1
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Luo Y, Hu Y, Yang J, Zhang M, Yung YL. Coupled atmospheric chemistry, radiation, and dynamics of an exoplanet generate self-sustained oscillations. Proc Natl Acad Sci U S A 2023; 120:e2309312120. [PMID: 38091286 PMCID: PMC10743409 DOI: 10.1073/pnas.2309312120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 10/13/2023] [Indexed: 12/24/2023] Open
Abstract
Nonlinearity in photochemical systems is known to allow self-sustained oscillations, but they have received little attention in studies of planetary atmospheres. Here, we present a unique, self-oscillatory solution for ozone chemistry of an exoplanet from a numerical simulation using a fully coupled, three-dimensional (3D) atmospheric chemistry-radiation-dynamics model. Forced with nonvarying stellar insolation and emission flux of nitric oxide (NO), atmospheric ozone abundance oscillates by a factor of thirty over a multidecadal timescale. As such self-oscillations can only occur with biological nitrogen fixation contributing to NO emission, we propose that they are a unique class of biosignature. The resulting temporal variability in the atmospheric spectrum is potentially observable. Our results underscore the importance of revisiting the spectra of exoplanets over multidecadal timescales to characterizing the atmospheric chemistry of exoplanets and searching for exoplanet biosignatures. There are also profound implications for comparative planetology and the evolution of the atmospheres of terrestrial planets in the solar system and beyond. Fully coupled, 3D atmospheric chemistry-radiation-dynamics models can reveal new phenomena that may not exist in one-dimensional models, and hence, they are powerful tools for future planetary atmospheric research.
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Affiliation(s)
- Yangcheng Luo
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
- Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing100871, China
- Laboratoire de Météorologie Dynamique/Institut Pierre-Simon Laplace, Sorbonne Université, École Normale Supérieure, Université Paris Sciences et Lettres, Ecole Polytechnique, Institut Polytechnique de Paris, Centre National de la Recherche Scientifique, Paris75005, France
| | - Yongyun Hu
- Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing100871, China
| | - Jun Yang
- Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing100871, China
| | - Michael Zhang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Yuk L. Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
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2
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Zeng ZC, Pongetti T, Newman S, Oda T, Gurney K, Palmer PI, Yung YL, Sander SP. Decadal decrease in Los Angeles methane emissions is much smaller than bottom-up estimates. Nat Commun 2023; 14:5353. [PMID: 37660143 PMCID: PMC10475107 DOI: 10.1038/s41467-023-40964-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 08/16/2023] [Indexed: 09/04/2023] Open
Abstract
Methane, a powerful greenhouse gas, has a short atmospheric lifetime ( ~ 12 years), so that emissions reductions will have a rapid impact on climate forcing. In megacities such as Los Angeles (LA), natural gas (NG) leakage is the primary atmospheric methane source. The magnitudes and trends of fugitive NG emissions are largely unknown and need to be quantified to verify compliance with emission reduction targets. Here we use atmospheric remote sensing data to show that, in contrast to the observed global increase in methane emissions, LA area emissions decreased during 2011-2020 at a mean rate of (-1.57 ± 0.41) %/yr. However, the NG utility calculations indicate a much larger negative emissions trend of -5.8 %/yr. The large difference between top-down and bottom-up trends reflects the uncertainties in estimating the achieved emissions reductions. Actions taken in LA can be a blueprint for COP28 and future efforts to reduce methane emissions.
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Affiliation(s)
- Zhao-Cheng Zeng
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Thomas Pongetti
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Sally Newman
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
- Planning and Climate Protection Division, Bay Area Air Quality Management District, San Francisco, CA, USA
| | - Tomohiro Oda
- Earth from Space Institute, Universities Space Research Association (USRA), Columbia, MD, USA
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, USA
- Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Kevin Gurney
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Paul I Palmer
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Yuk L Yung
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Stanley P Sander
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
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3
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Kuai L, Parazoo NC, Shi M, Miller CE, Baker I, Bloom AA, Bowman K, Lee M, Zeng Z, Commane R, Montzka SA, Berry J, Sweeney C, Miller JB, Yung YL. Quantifying Northern High Latitude Gross Primary Productivity (GPP) Using Carbonyl Sulfide (OCS). Global Biogeochem Cycles 2022; 36:e2021GB007216. [PMID: 36590828 PMCID: PMC9787914 DOI: 10.1029/2021gb007216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 07/21/2022] [Accepted: 08/08/2022] [Indexed: 06/17/2023]
Abstract
The northern high latitude (NHL, 40°N to 90°N) is where the second peak region of gross primary productivity (GPP) other than the tropics. The summer NHL GPP is about 80% of the tropical peak, but both regions are still highly uncertain (Norton et al. 2019, https://doi.org/10.5194/bg-16-3069-2019). Carbonyl sulfide (OCS) provides an important proxy for photosynthetic carbon uptake. Here we optimize the OCS plant uptake fluxes across the NHL by fitting atmospheric concentration simulation with the GEOS-CHEM global transport model to the aircraft profiles acquired over Alaska during NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (2012-2015). We use the empirical biome-specific linear relationship between OCS plant uptake flux and GPP to derive the six plant uptake OCS fluxes from different GPP data. Such GPP-based fluxes are used to drive the concentration simulations. We evaluate the simulations against the independent observations at two ground sites of Alaska. The optimized OCS fluxes suggest the NHL plant uptake OCS flux of -247 Gg S year-1, about 25% stronger than the ensemble mean of the six GPP-based OCS fluxes. GPP-based OCS fluxes systematically underestimate the peak growing season across the NHL, while a subset of models predict early start of season in Alaska, consistent with previous studies of net ecosystem exchange. The OCS optimized GPP of 34 PgC yr-1 for NHL is also about 25% more than the ensembles mean from six GPP data. Further work is needed to fully understand the environmental and biotic drivers and quantify their rate of photosynthetic carbon uptake in Arctic ecosystems.
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Affiliation(s)
- Le Kuai
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | | | - Mingjie Shi
- Pacific Northwest National LaboratoryRichlandWAUSA
| | - Charles E. Miller
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Ian Baker
- Colorado State UniversityFort CollinsCOUSA
| | - Anthony A. Bloom
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Kevin Bowman
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Meemong Lee
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Zhao‐Cheng Zeng
- University of California Los AngelesJIFRESSELos AngelesCAUSA
| | - Roisin Commane
- Lamont‐Doherty Earth Observatory at Columbia UniversityPalisadesNYUSA
| | | | | | | | | | - Yuk L. Yung
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
- California Institute of TechnologyPasadenaCAUSA
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4
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Le T, Natraj V, Braverman AJ, Yung YL. Evaluation of Modeled Hyperspectral Infrared Spectra Against All-Sky AIRS Observations Using Different Cloud Overlap Schemes. Earth Space Sci 2022; 9:e2022EA002245. [PMID: 35859723 PMCID: PMC9285748 DOI: 10.1029/2022ea002245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/08/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
Hyperspectral infrared sounding contains information about clouds, which plays an important role in modulating Earth's climate. However, there is a great deal of uncertainty in modeling the radiative effect of clouds due to its complex dependence on various parameters. Therefore, cloudy scenarios are often neglected in retrievals of infrared spectral measurements and in data assimilation. One-dimensional radiative transfer (RT) models have a limited capability to represent the cloud three-dimensional multilayer structure. This issue is typically resolved by using a multiple independent column approach, which is computationally demanding. Therefore, it is necessary to find a balance between computational speed and accuracy for infrared RT all-sky radiance simulations. In this study, we utilize the Community Radiative Transfer Model with four different cloud overlap schemes and compare against observations made by the Atmospheric Infrared Sounder (AIRS) using a statistical metric called the first Wasserstein distance. Our results show that the average cloud overlap scheme performs the best and successfully predicts the overall probability distribution of brightness temperature over nonfrozen oceans for a wide range of wavelengths. The mean absolute differences are less than 0.7 K for 846 selected AIRS channels between 790 cm-1 and 1231 cm-1.
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Affiliation(s)
- Tianhao Le
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - Vijay Natraj
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Amy J. Braverman
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Yuk L. Yung
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
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5
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Bartlett S, Gao AK, Yung YL. Computation by Convective Logic Gates and Thermal Communication. Artif Life 2022; 28:96-107. [PMID: 35358297 DOI: 10.1162/artl_a_00358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We demonstrate a novel computational architecture based on fluid convection logic gates and heat flux-mediated information flows. Our previous work demonstrated that Boolean logic operations can be performed by thermally driven convection flows. In this work, we use numerical simulations to demonstrate a different , but universal Boolean logic operation (NOR), performed by simpler convective gates. The gates in the present work do not rely on obstacle flows or periodic boundary conditions, a significant improvement in terms of experimental realizability. Conductive heat transfer links can be used to connect the convective gates, and we demonstrate this with the example of binary half addition. These simulated circuits could be constructed in an experimental setting with modern, 2-dimensional fluidics equipment, such as a thin layer of fluid between acrylic plates. The presented approach thus introduces a new realm of unconventional, thermal fluid-based computation.
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Affiliation(s)
- Stuart Bartlett
- California Institute of Technology, Division of Geological and Planetary Sciences.
- Tokyo Institute of Technology, Earth-Life Science Institute
| | - Andrew K Gao
- California Institute of Technology, Division of Geological and Planetary Sciences
- Peking University, Yuanpei College
| | - Yuk L Yung
- California Institute of Technology, Division of Geological and Planetary Sciences
- NASA Jet Propulsion Laboratory
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6
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Fan S, Gao P, Zhang X, Adams DJ, Kutsop NW, Bierson CJ, Liu C, Yang J, Young LA, Cheng AF, Yung YL. A bimodal distribution of haze in Pluto's atmosphere. Nat Commun 2022; 13:240. [PMID: 35017491 PMCID: PMC8752795 DOI: 10.1038/s41467-021-27811-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022] Open
Abstract
Pluto, Titan, and Triton make up a unique class of solar system bodies, with icy surfaces and chemically reducing atmospheres rich in organic photochemistry and haze formation. Hazes play important roles in these atmospheres, with physical and chemical processes highly dependent on particle sizes, but the haze size distribution in reducing atmospheres is currently poorly understood. Here we report observational evidence that Pluto’s haze particles are bimodally distributed, which successfully reproduces the full phase scattering observations from New Horizons. Combined with previous simulations of Titan’s haze, this result suggests that haze particles in reducing atmospheres undergo rapid shape change near pressure levels ~0.5 Pa and favors a photochemical rather than a dynamical origin for the formation of Titan’s detached haze. It also demonstrates that both oxidizing and reducing atmospheres can produce multi-modal hazes, and encourages reanalysis of observations of hazes on Titan and Triton. Pluto’s haze is revealed to have two types of particles: small spherical organic haze particles and micron-size fluffy aggregates. The persistence of these two populations has important implications for haze formation and properties on icy worlds.
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Affiliation(s)
- Siteng Fan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA. .,LMD/IPSL, Sorbonne Université, PSL Research University, École Normale Supérieure, École Polytechnique, CNRS, Paris, 75005, France.
| | - Peter Gao
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, 20015, USA
| | - Xi Zhang
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Danica J Adams
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | | | - Carver J Bierson
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA, 95064, USA.,School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85281, USA
| | - Chao Liu
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.,Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Jiani Yang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | | | - Andrew F Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, 20723, USA
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
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7
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Albright R, Corbett A, Jiang X, Creecy E, Newman S, Li K, Liang M, Yung YL. Seasonal Variations of Solar-Induced Fluorescence, Precipitation, and Carbon Dioxide Over the Amazon. Earth Space Sci 2022; 9:e2021EA002078. [PMID: 35860761 PMCID: PMC9285695 DOI: 10.1029/2021ea002078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/20/2021] [Accepted: 11/24/2021] [Indexed: 06/15/2023]
Abstract
Previous studies suggested that the Amazon, the largest rainforest on Earth, changes from a CO2 sink to a CO2 source during the dry/fire season. However, the biospheric contributions to atmospheric CO2 are not well understood during the two main seasons, the dry/fire season and the wet season. In this article, we utilize Orbiting Carbon Observatory 2 (OCO-2) Solar-Induced Fluorescence (SIF) to explore photosynthetic activity during the different seasons. The spatiotemporal variability of OCO-2 SIF, OCO-2 CO2, precipitation, and burned area are investigated over the Amazon from September 2014 to December 2019. Averaging over the entire Amazon region, we found a positive temporal correlation (0.94) between OCO-2 SIF and Global Precipitation Climatology Project precipitation and a negative temporal correlation (-0.64) between OCO-2 SIF and OCO-2 CO2, consistent with the fact that precipitation enhances photosynthesis, which results in higher values for SIF and rate of removal of CO2 from the atmosphere above the Amazon region. We also observed seasonality in the spatial variability of these variables within the Amazon region. During the dry/fire (August-October) season, low SIF values, low precipitation, high vapor pressure deficit (VPD), large burned areas, and high atmospheric CO2 are mainly found over the southern Amazon region. In contrast, during the wet season (January-March), high SIF values, high precipitation, low VPD, smaller burned areas, and low CO2 are found over both the central and southern Amazon regions. The seasonal difference in SIF suggests that photosynthetic activity is reduced during the dry/fire season relative to the wet season as a result of low precipitation and high VPD, especially over the southern Amazon region, which will contribute to more CO2 in the atmosphere during the dry/fire season.
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Affiliation(s)
- Ronald Albright
- Department of Earth & Atmospheric SciencesUniversity of HoustonHoustonTXUSA
| | - Abigail Corbett
- Department of Earth & Atmospheric SciencesUniversity of HoustonHoustonTXUSA
- SeekOps IncAustinTXUSA
| | - Xun Jiang
- Department of Earth & Atmospheric SciencesUniversity of HoustonHoustonTXUSA
| | - Ellen Creecy
- Department of Earth & Atmospheric SciencesUniversity of HoustonHoustonTXUSA
| | - Sally Newman
- Bay Area Air Quality Management DistrictSan FranciscoCAUSA
| | - King‐Fai Li
- Department of Environmental SciencesUniversity of CaliforniaRiversideCAUSA
| | | | - Yuk L. Yung
- Division of Geological and Planetary Sciences, California Institute of TechnologyPasadenaCAUSA
- Jet Propulsion LaboratoryPasadenaCAUSA
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8
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Laughner JL, Neu JL, Schimel D, Wennberg PO, Barsanti K, Bowman KW, Chatterjee A, Croes BE, Fitzmaurice HL, Henze DK, Kim J, Kort EA, Liu Z, Miyazaki K, Turner AJ, Anenberg S, Avise J, Cao H, Crisp D, de Gouw J, Eldering A, Fyfe JC, Goldberg DL, Gurney KR, Hasheminassab S, Hopkins F, Ivey CE, Jones DBA, Liu J, Lovenduski NS, Martin RV, McKinley GA, Ott L, Poulter B, Ru M, Sander SP, Swart N, Yung YL, Zeng ZC. Societal shifts due to COVID-19 reveal large-scale complexities and feedbacks between atmospheric chemistry and climate change. Proc Natl Acad Sci U S A 2021; 118:e2109481118. [PMID: 34753820 PMCID: PMC8609622 DOI: 10.1073/pnas.2109481118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2021] [Indexed: 11/21/2022] Open
Abstract
The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. The resulting reductions in anthropogenic activity represent an unprecedented event that yields a glimpse into a future where emissions to the atmosphere are reduced. Furthermore, the abrupt reduction in emissions during the lockdown periods led to clearly observable changes in atmospheric composition, which provide direct insight into feedbacks between the Earth system and human activity. While air pollutants and greenhouse gases share many common anthropogenic sources, there is a sharp difference in the response of their atmospheric concentrations to COVID-19 emissions changes, due in large part to their different lifetimes. Here, we discuss several key takeaways from modeling and observational studies. First, despite dramatic declines in mobility and associated vehicular emissions, the atmospheric growth rates of greenhouse gases were not slowed, in part due to decreased ocean uptake of CO2 and a likely increase in CH4 lifetime from reduced NO x emissions. Second, the response of O3 to decreased NO x emissions showed significant spatial and temporal variability, due to differing chemical regimes around the world. Finally, the overall response of atmospheric composition to emissions changes is heavily modulated by factors including carbon-cycle feedbacks to CH4 and CO2, background pollutant levels, the timing and location of emissions changes, and climate feedbacks on air quality, such as wildfires and the ozone climate penalty.
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Affiliation(s)
- Joshua L Laughner
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125;
| | - Jessica L Neu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
| | - David Schimel
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
| | - Paul O Wennberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125;
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Kelley Barsanti
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521
- Center for Environmental Research and Technology, Riverside, CA 92507
| | - Kevin W Bowman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Abhishek Chatterjee
- Goddard Earth Sciences Technology and Research, Universities Space Research Association, Columbia, MD 21046
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD 20771
| | - Bart E Croes
- Energy Research and Development Division, California Energy Commission, Sacramento, CA 95814
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309
| | - Helen L Fitzmaurice
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720
| | - Daven K Henze
- Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309
| | - Jinsol Kim
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720
| | - Eric A Kort
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Zhu Liu
- Department of Earth System Science, Tsinghua University, Beijing 100084, China
| | - Kazuyuki Miyazaki
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Alexander J Turner
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195
| | - Susan Anenberg
- Milken Institute School of Public Health, George Washington University, Washington, DC 20052
| | - Jeremy Avise
- Modeling and Meteorology Branch, California Air Resources Board, Sacramento, CA 95814
| | - Hansen Cao
- Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309
| | - David Crisp
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Joost de Gouw
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309
- Department of Chemistry, University of Colorado, Boulder, CO 80309
| | - Annmarie Eldering
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - John C Fyfe
- Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change Canada, Victoria, BC, V8W 2Y2 Canada
| | - Daniel L Goldberg
- Milken Institute School of Public Health, George Washington University, Washington, DC 20052
| | - Kevin R Gurney
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ 86011
| | - Sina Hasheminassab
- Science and Technology Advancement Division, South Coast Air Quality Management District, Diamond Bar, CA, 91765
| | - Francesca Hopkins
- Department of Environmental Sciences, University of California, Riverside, CA 92521
| | - Cesunica E Ivey
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521
- Center for Environmental Research and Technology, Riverside, CA 92507
| | - Dylan B A Jones
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A1 Canada
| | - Junjie Liu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Nicole S Lovenduski
- Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, CO 80309
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309
| | - Randall V Martin
- McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Galen A McKinley
- Department of Earth and Environmental Sciences, Lamont Doherty Earth Observatory, Columbia University, Palisades, NY 10964
| | - Lesley Ott
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD 20771
| | - Benjamin Poulter
- Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771
| | - Muye Ru
- The Earth Institute, Columbia University, New York, NY 10025
- Nicholas School of the Environment, Duke University, Durham, NC 27707
| | - Stanley P Sander
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Neil Swart
- Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change Canada, Victoria, BC, V8W 2Y2 Canada
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Zhao-Cheng Zeng
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, CA 90095
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9
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Yang J, Wen Y, Wang Y, Zhang S, Pinto JP, Pennington EA, Wang Z, Wu Y, Sander SP, Jiang JH, Hao J, Yung YL, Seinfeld JH. From COVID-19 to future electrification: Assessing traffic impacts on air quality by a machine-learning model. Proc Natl Acad Sci U S A 2021; 118:e2102705118. [PMID: 34155113 PMCID: PMC8256029 DOI: 10.1073/pnas.2102705118] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The large fluctuations in traffic during the COVID-19 pandemic provide an unparalleled opportunity to assess vehicle emission control efficacy. Here we develop a random-forest regression model, based on the large volume of real-time observational data during COVID-19, to predict surface-level NO2, O3, and fine particle concentration in the Los Angeles megacity. Our model exhibits high fidelity in reproducing pollutant concentrations in the Los Angeles Basin and identifies major factors controlling each species. During the strictest lockdown period, traffic reduction led to decreases in NO2 and particulate matter with aerodynamic diameters <2.5 μm by -30.1% and -17.5%, respectively, but a 5.7% increase in O3 Heavy-duty truck emissions contribute primarily to these variations. Future traffic-emission controls are estimated to impose similar effects as observed during the COVID-19 lockdown, but with smaller magnitude. Vehicular electrification will achieve further alleviation of NO2 levels.
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Affiliation(s)
- Jiani Yang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Yifan Wen
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125;
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Shaojun Zhang
- School of Environment, Tsinghua University, Beijing 100084, China;
| | - Joseph P Pinto
- Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Elyse A Pennington
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Zhou Wang
- Department of Geography, University of Mainz, 55099 Mainz, Germany
| | - Ye Wu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Stanley P Sander
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Jonathan H Jiang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Jiming Hao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - John H Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125;
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10
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Scheller EL, Ehlmann BL, Hu R, Adams DJ, Yung YL. Long-term drying of Mars by sequestration of ocean-scale volumes of water in the crust. Science 2021; 372:56-62. [PMID: 33727251 DOI: 10.1126/science.abc7717] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 03/04/2021] [Indexed: 11/02/2022]
Abstract
Geological evidence shows that ancient Mars had large volumes of liquid water. Models of past hydrogen escape to space, calibrated with observations of the current escape rate, cannot explain the present-day deuterium-to-hydrogen isotope ratio (D/H). We simulated volcanic degassing, atmospheric escape, and crustal hydration on Mars, incorporating observational constraints from spacecraft, rovers, and meteorites. We found that ancient water volumes equivalent to a 100 to 1500 meter global layer are simultaneously compatible with the geological evidence, loss rate estimates, and D/H measurements. In our model, the volume of water participating in the hydrological cycle decreased by 40 to 95% over the Noachian period (~3.7 billion to 4.1 billion years ago), reaching present-day values by ~3.0 billion years ago. Between 30 and 99% of martian water was sequestered through crustal hydration, demonstrating that irreversible chemical weathering can increase the aridity of terrestrial planets.
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Affiliation(s)
- E L Scheller
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
| | - B L Ehlmann
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - Renyu Hu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - D J Adams
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Y L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
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11
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Pinto JP, Li J, Mills FP, Marcq E, Evdokimova D, Belyaev D, Yung YL. Sulfur monoxide dimer chemistry as a possible source of polysulfur in the upper atmosphere of Venus. Nat Commun 2021; 12:175. [PMID: 33420044 PMCID: PMC7794339 DOI: 10.1038/s41467-020-20451-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 11/27/2020] [Indexed: 11/09/2022] Open
Abstract
The abundance of SO dimers (SO)2 in the upper atmosphere of Venus and their implications for the enigmatic ultraviolet absorption has been investigated in several studies over the past few years. However, the photochemistry of sulfur species in the upper atmosphere of Venus is still not well understood and the identity of the missing ultraviolet absorber(s) remains unknown. Here we update an existing photochemical model of Venus’ upper atmosphere by including the photochemistry of SO dimers. Although the spectral absorption profile of SO dimers fits the unknown absorber, their abundance is found to be too low for them to contribute significantly to the absorption. It is more likely that their photolysis and/or reaction products could contribute more substantively. Reactions of SO dimers are found to be important sources of S2O, and possibly higher order SnO species and polysulfur, Sn. All of these species absorb in the critical ultraviolet region and are expected to be found in both the aerosol and gas phase. indicating that in-situ high resolution aerosol mass spectrometry might be a useful technique for identifying the ultraviolet absorber on Venus. Photochemistry of sulfur species in the upper Venus atmosphere is not well understood and the identity of ultraviolet (UV) absorber(s) remain unknown. Here, the authors show that sulfur monoxide dimer chemistry is a possible source of polysulfur, which could be responsible for the UV absorption.
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Affiliation(s)
- Joseph P Pinto
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jiazheng Li
- Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA, USA.
| | - Franklin P Mills
- Australian National University, Canberra, ACT, Australia.,Space Science Institute, Boulder, CO, USA
| | | | - Daria Evdokimova
- LATMOS/CNRS/Sorbonne Université/UVSQ, Paris, France.,Space Research Institute of the Russian Academy of Sciences (IKI), Moscow, Russia
| | - Denis Belyaev
- Space Research Institute of the Russian Academy of Sciences (IKI), Moscow, Russia
| | - Yuk L Yung
- Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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12
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Zhao D, Bartlett S, Yung YL. Quantifying Mineral-Ligand Structural Similarities: Bridging the Geological World of Minerals with the Biological World of Enzymes. Life (Basel) 2020; 10:life10120338. [PMID: 33321803 PMCID: PMC7764262 DOI: 10.3390/life10120338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/15/2020] [Accepted: 12/07/2020] [Indexed: 01/10/2023] Open
Abstract
Metal compounds abundant on Early Earth are thought to play an important role in the origins of life. Certain iron-sulfur minerals for example, are proposed to have served as primitive metalloenzyme cofactors due to their ability to catalyze organic synthesis processes and facilitate electron transfer reactions. An inherent difficulty with studying the catalytic potential of many metal compounds is the wide range of data and parameters to consider when searching for individual minerals and ligands of interest. Detecting mineral-ligand pairs that are structurally analogous enables more relevant selections of data to study, since structural affinity is a key indicator of comparable catalytic function. However, current structure-oriented approaches tend to be subjective and localized, and do not quantify observations or compare them with other potential targets. Here, we present a mathematical approach that compares structural similarities between various minerals and ligands using molecular similarity metrics. We use an iterative substructure search in the crystal lattice, paired with benchmark structural similarity methods. This structural comparison may be considered as a first stage in a more advanced analysis tool that will include a range of chemical and physical factors when computing mineral-ligand similarity. This approach will seek relationships between the mineral and enzyme worlds, with applications to the origins of life, ecology, catalysis, and astrobiology.
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Affiliation(s)
- Daniel Zhao
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (D.Z.); (Y.L.Y.)
- Department of Mathematics, Harvard University, Massachusetts Hall, Cambridge, MA 02138, USA
| | - Stuart Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (D.Z.); (Y.L.Y.)
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- Correspondence:
| | - Yuk L. Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; (D.Z.); (Y.L.Y.)
- NASA Jet Propulsion Laboratory, Oak Grove Dr, La Cañada Flintridge, CA 91011, USA
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13
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Le T, Wang Y, Liu L, Yang J, Yung YL, Li G, Seinfeld JH. Unexpected air pollution with marked emission reductions during the COVID-19 outbreak in China. Science 2020; 369:702-706. [PMID: 32554754 PMCID: PMC7402623 DOI: 10.1126/science.abb7431] [Citation(s) in RCA: 336] [Impact Index Per Article: 84.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 06/09/2020] [Indexed: 12/26/2022]
Abstract
The absence of motor vehicle traffic and suspended manufacturing during the coronavirus disease 2019 (COVID-19) pandemic in China enabled assessment of the efficiency of air pollution mitigation. Up to 90% reduction of certain emissions during the city-lockdown period can be identified from satellite and ground-based observations. Unexpectedly, extreme particulate matter levels simultaneously occurred in northern China. Our synergistic observation analyses and model simulations show that anomalously high humidity promoted aerosol heterogeneous chemistry, along with stagnant airflow and uninterrupted emissions from power plants and petrochemical facilities, contributing to severe haze formation. Also, because of nonlinear production chemistry and titration of ozone in winter, reduced nitrogen oxides resulted in ozone enhancement in urban areas, further increasing the atmospheric oxidizing capacity and facilitating secondary aerosol formation.
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Affiliation(s)
- Tianhao Le
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Lang Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China
- Key Lab of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China
| | - Jiani Yang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Guohui Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China
- Key Lab of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China
| | - John H Seinfeld
- Divisions of Chemistry and Chemical Engineering and Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA
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14
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Abstract
Spatially resolving exoplanet features from single-point observations is essential for evaluating the potential habitability of exoplanets. The ultimate goal of this protocol is to determine whether these planetary worlds harbor geological features and/or climate systems. We present a method of extracting information from multi-wavelength single-point light curves and retrieving surface maps. It uses singular value decomposition (SVD) to separate sources that contribute to light curve variations and infer the existence of partially cloudy climate systems. Through analysis of the time series obtained from SVD, physical attributions of principal components (PCs) could be inferred without assumptions of any spectral properties. Combining with viewing geometry, it is feasible to reconstruct surface maps if one of the PCs are found to contain surface information. Degeneracy originated from convolution of the pixel geometry and spectrum information determines the quality of reconstructed surface maps, which requires the introduction of regularization. For the purpose of demonstrating the protocol, multi-wavelength light curves of Earth, which serves as a proxy exoplanet, are analyzed. Comparison between the results and the ground truth is presented to show the performance and limitation of the protocol. This work provides a benchmark for future generalization of exoplanet applications.
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Affiliation(s)
- Siteng Fan
- Division of Geological and Planetary Sciences, California Institute of Technology;
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology
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15
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Zhao B, Wang Y, Gu Y, Liou KN, Jiang JH, Fan J, Liu X, Huang L, Yung YL. Ice nucleation by aerosols from anthropogenic pollution. Nat Geosci 2019; 12:602-607. [PMID: 31360220 PMCID: PMC6662716 DOI: 10.1038/s41561-019-0389-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 05/15/2019] [Indexed: 05/27/2023]
Abstract
The formation of ice particles in the atmosphere strongly affects cloud properties and the climate. While mineral dust is known to be an effective ice nucleating particle, the role of aerosols from anthropogenic pollution in ice nucleation is still under debate. Here we probe the ice nucleation ability of different aerosol types by combining 11-year observations from multiple satellites and cloud-resolving model simulations. We find that, for strong convective systems, ice particle effective radius near cloud top decreases with increasing loading of polluted continental aerosols, because the ice formation is dominated by homogeneous freezing of cloud droplets that are smaller under more polluted conditions. In contrast, an increase in ice particle effective radius with polluted continental aerosols is found for moderate convection. Our model simulations suggest that this positive correlation is explained by enhanced heterogeneous ice nucleation and prolonged ice particle growth at larger aerosol loading, indicating that polluted continental aerosols contain a significant fraction of ice nucleating particles. Similar aerosol-ice relationships are observed for dust aerosols, further corroborating the ice nucleation ability of polluted continental aerosols. By catalyzing ice formation, aerosols from anthropogenic pollution could have profound impacts on cloud lifetime and radiative effect as well as precipitation efficiency.
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Affiliation(s)
- Bin Zhao
- Joint Institute for Regional Earth System Science and
Engineering and Department of Atmospheric and Oceanic Sciences, University of
California, Los Angeles, California 90095, USA
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California
Institute of Technology, Pasadena, California 91109, USA
- Jet propulsion Laboratory, California Institute of
Technology, Pasadena, California 91109, USA
| | - Yu Gu
- Joint Institute for Regional Earth System Science and
Engineering and Department of Atmospheric and Oceanic Sciences, University of
California, Los Angeles, California 90095, USA
| | - Kuo-Nan Liou
- Joint Institute for Regional Earth System Science and
Engineering and Department of Atmospheric and Oceanic Sciences, University of
California, Los Angeles, California 90095, USA
| | - Jonathan H. Jiang
- Jet propulsion Laboratory, California Institute of
Technology, Pasadena, California 91109, USA
| | - Jiwen Fan
- Atmospheric Sciences and Global Change Division, Pacific
Northwest National Laboratory, Richland, Washington 99352, USA
| | - Xiaohong Liu
- Department of Atmospheric Science, University of Wyoming,
Laramie, Wyoming 82071, USA
| | - Lei Huang
- Jet propulsion Laboratory, California Institute of
Technology, Pasadena, California 91109, USA
| | - Yuk L. Yung
- Division of Geological and Planetary Sciences, California
Institute of Technology, Pasadena, California 91109, USA
- Jet propulsion Laboratory, California Institute of
Technology, Pasadena, California 91109, USA
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16
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Liu H, Guo J, Koren I, Altaratz O, Dagan G, Wang Y, Jiang JH, Zhai P, Yung YL. Non-Monotonic Aerosol Effect on Precipitation in Convective Clouds over Tropical Oceans. Sci Rep 2019; 9:7809. [PMID: 31127137 PMCID: PMC6534586 DOI: 10.1038/s41598-019-44284-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/14/2019] [Indexed: 11/22/2022] Open
Abstract
Aerosol effects on convective clouds and associated precipitation constitute an important open-ended question in climate research. Previous studies have linked an increase in aerosol concentration to a delay in the onset of rain, invigorated clouds and stronger rain rates. Here, using observational data, we show that the aerosol effect on convective clouds shifts from invigoration to suppression with increasing aerosol optical depth. We explain this shift in trend (using a cloud model) as the result of a competition between two types of microphysical processes: cloud-core-based invigorating processes vs. peripheral suppressive processes. We show that the aerosol optical depth value that marks the shift between invigoration and suppression depends on the environmental thermodynamic conditions. These findings can aid in better parameterizing aerosol effects in climate models for the prediction of climate trends.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.,Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Jianping Guo
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.
| | - Ilan Koren
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Orit Altaratz
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Guy Dagan
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Jonathan H Jiang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Panmao Zhai
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
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17
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Bartlett SJ, Yung YL. Convective flow in the presence of a small obstacle: Symmetry breaking, attractors, hysteresis, and information. Phys Rev E 2019; 99:033103. [PMID: 30999451 DOI: 10.1103/physreve.99.033103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Indexed: 11/07/2022]
Abstract
This work explores the stability and hysteresis effects that occur when a small sink of momentum is introduced into a heat-driven, two-dimensional convective flow. As per standard fluid mechanical intuition, the system minimizes work generation and dissipation when one component of momentum is extracted. However, when the sink absorbs all incoming momentum, the system configures itself such that one of the convection plumes aligns directly with the sink. This state is the most hydrodynamically stable, but it maximizes, rather than minimizes extracted mechanical work. Furthermore, in the case of only vertical momentum extraction, there are two attractors, with different stabilities. Numerical experiments involving slow variations of the horizontal momentum extraction show a clear history dependence. This hysteresis preserves information about the system's past states, and hence represents a primitive memory. The momentum sink can also be used to manipulate the horizontal position of the flow field, with potential applications in microfluidics and laminar convection systems. This simple system exhibits the phenomena of autocatalysis (during the initial growth of the convection plumes), negative feedback (the attractors are either fully or quasistable), memory, and elementary computation.
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Affiliation(s)
- S J Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA and Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Y L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA and Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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18
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Wang Y, Ma P, Peng J, Zhang R, Jiang JH, Easter RC, Yung YL. Constraining Aging Processes of Black Carbon in the Community Atmosphere Model Using Environmental Chamber Measurements. J Adv Model Earth Syst 2018; 10:2514-2526. [PMID: 31031881 PMCID: PMC6472719 DOI: 10.1029/2018ms001387] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/03/2018] [Accepted: 10/03/2018] [Indexed: 05/30/2023]
Abstract
The direct radiative forcing of black carbon aerosol (BC) on the Earth system remains unsettled, largely due to the uncertainty with physical properties of BC throughout their lifecycle. Here we show that ambient chamber measurements of BC properties provide a novel constraint on the crude BC aging representation in climate models. Observational evidence for significant absorption enhancement of BC can be reproduced when the aging processes in the four-mode version of the Modal Aerosol Module (MAM4) aerosol scheme in the Community Atmosphere Model version 5 are calibrated by the recent in situ chamber measurements. An observation-based scaling method is developed in the aging timescale calculation to alleviate the influence of biases in the simulated model chemical composition. Model sensitivity simulations suggest that the different monolayer settings in the BC aging parameterization of MAM4 can cause as large as 26% and 24% differences in BC burden and radiative forcing, respectively. We also find that an increase in coating materials (e.g., sulfate and secondary organic aerosols) reduces BC lifetime by increasing the hygroscopicity of the mixture but enhances its absorption, resulting in a net increase in BC direct radiative forcing. Our results suggest that accurate simulations of BC aging processes as well as other aerosol species are equally important in reducing the uncertainty of BC forcing estimation.
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Affiliation(s)
- Yuan Wang
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Po‐Lun Ma
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LaboratoryRichlandWAUSA
| | - Jianfei Peng
- Department of Atmospheric SciencesTexas A&M UniversityCollege StationTXUSA
| | - Renyi Zhang
- Department of Atmospheric SciencesTexas A&M UniversityCollege StationTXUSA
| | - Jonathan H. Jiang
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Richard C. Easter
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LaboratoryRichlandWAUSA
| | - Yuk L. Yung
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
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19
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Yung YL, Chen P, Nealson K, Atreya S, Beckett P, Blank JG, Ehlmann B, Eiler J, Etiope G, Ferry JG, Forget F, Gao P, Hu R, Kleinböhl A, Klusman R, Lefèvre F, Miller C, Mischna M, Mumma M, Newman S, Oehler D, Okumura M, Oremland R, Orphan V, Popa R, Russell M, Shen L, Sherwood Lollar B, Staehle R, Stamenković V, Stolper D, Templeton A, Vandaele AC, Viscardy S, Webster CR, Wennberg PO, Wong ML, Worden J. Methane on Mars and Habitability: Challenges and Responses. Astrobiology 2018; 18:1221-1242. [PMID: 30234380 PMCID: PMC6205098 DOI: 10.1089/ast.2018.1917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 06/12/2018] [Indexed: 05/05/2023]
Abstract
Recent measurements of methane (CH4) by the Mars Science Laboratory (MSL) now confront us with robust data that demand interpretation. Thus far, the MSL data have revealed a baseline level of CH4 (∼0.4 parts per billion by volume [ppbv]), with seasonal variations, as well as greatly enhanced spikes of CH4 with peak abundances of ∼7 ppbv. What do these CH4 revelations with drastically different abundances and temporal signatures represent in terms of interior geochemical processes, or is martian CH4 a biosignature? Discerning how CH4 generation occurs on Mars may shed light on the potential habitability of Mars. There is no evidence of life on the surface of Mars today, but microbes might reside beneath the surface. In this case, the carbon flux represented by CH4 would serve as a link between a putative subterranean biosphere on Mars and what we can measure above the surface. Alternatively, CH4 records modern geochemical activity. Here we ask the fundamental question: how active is Mars, geochemically and/or biologically? In this article, we examine geological, geochemical, and biogeochemical processes related to our overarching question. The martian atmosphere and surface are an overwhelmingly oxidizing environment, and life requires pairing of electron donors and electron acceptors, that is, redox gradients, as an essential source of energy. Therefore, a fundamental and critical question regarding the possibility of life on Mars is, "Where can we find redox gradients as energy sources for life on Mars?" Hence, regardless of the pathway that generates CH4 on Mars, the presence of CH4, a reduced species in an oxidant-rich environment, suggests the possibility of redox gradients supporting life and habitability on Mars. Recent missions such as ExoMars Trace Gas Orbiter may provide mapping of the global distribution of CH4. To discriminate between abiotic and biotic sources of CH4 on Mars, future studies should use a series of diagnostic geochemical analyses, preferably performed below the ground or at the ground/atmosphere interface, including measurements of CH4 isotopes, methane/ethane ratios, H2 gas concentration, and species such as acetic acid. Advances in the fields of Mars exploration and instrumentation will be driven, augmented, and supported by an improved understanding of atmospheric chemistry and dynamics, deep subsurface biogeochemistry, astrobiology, planetary geology, and geophysics. Future Mars exploration programs will have to expand the integration of complementary areas of expertise to generate synergistic and innovative ideas to realize breakthroughs in advancing our understanding of the potential of life and habitable conditions having existed on Mars. In this spirit, we conducted a set of interdisciplinary workshops. From this series has emerged a vision of technological, theoretical, and methodological innovations to explore the martian subsurface and to enhance spatial tracking of key volatiles, such as CH4.
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Affiliation(s)
- Yuk L. Yung
- California Institute of Technology, Pasadena, California
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Pin Chen
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | | | | | - Jennifer G. Blank
- NASA Ames Research Center, Blue Marble Space Institute of Science, Mountain View, California
| | - Bethany Ehlmann
- California Institute of Technology, Pasadena, California
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - John Eiler
- California Institute of Technology, Pasadena, California
| | - Giuseppe Etiope
- Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
- Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
| | - James G. Ferry
- The Pennsylvania State University, University Park, Pennsylvania
| | - Francois Forget
- Laboratoire de Météorologie Dynamique, Institut Pierre Simon Laplace, CNRS, Paris, France
| | - Peter Gao
- University of California, Berkeley, California
| | - Renyu Hu
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Armin Kleinböhl
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | - Franck Lefèvre
- Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS), IPSL, Paris, France
| | - Charles Miller
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Michael Mischna
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Michael Mumma
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Sally Newman
- California Institute of Technology, Pasadena, California
| | | | | | | | | | - Radu Popa
- University of Southern California, Los Angeles, California
| | - Michael Russell
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Linhan Shen
- California Institute of Technology, Pasadena, California
| | | | - Robert Staehle
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | - Vlada Stamenković
- California Institute of Technology, Pasadena, California
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | | | - Ann C. Vandaele
- The Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
| | - Sébastien Viscardy
- The Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
| | - Christopher R. Webster
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
| | | | | | - John Worden
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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20
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Wong ML, Charnay BD, Gao P, Yung YL, Russell MJ. Nitrogen Oxides in Early Earth's Atmosphere as Electron Acceptors for Life's Emergence. Astrobiology 2017; 17:975-983. [PMID: 29023147 DOI: 10.1089/ast.2016.1473] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We quantify the amount of nitrogen oxides (NOx) produced through lightning and photochemical processes in the Hadean atmosphere to be available in the Hadean ocean for the emergence of life. Atmospherically generated nitrate (NO3-) and nitrite (NO2-) are the most attractive high-potential electron acceptors for pulling and enabling crucial redox reactions of autotrophic metabolic pathways at submarine alkaline hydrothermal vents. The Hadean atmosphere, dominated by CO2 and N2, will produce nitric oxide (NO) when shocked by lightning. Photochemical reactions involving NO and H2O vapor will then produce acids such as HNO, HNO2, HNO3, and HO2NO2 that rain into the ocean. There, they dissociate into or react to form nitrate and nitrite. We present new calculations based on a novel combination of early-Earth global climate model and photochemical modeling, and we predict the flux of NOx to the Hadean ocean. In our 0.1-, 1-, and 10-bar pCO2 models, we calculate the NOx delivery to be 2.4 × 105, 6.5 × 108, and 1.9 × 108 molecules cm-2 s-1. After only tens of thousands to tens of millions of years, these NOx fluxes are expected to produce sufficient (micromolar) ocean concentrations of high-potential electron acceptors for the emergence of life. Key Words: Nitrogen oxides-Nitrate-Nitrite-Photochemistry-Lightning-Emergence of life. Astrobiology 17, 975-983.
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Affiliation(s)
- Michael L Wong
- 1 Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California
| | - Benjamin D Charnay
- 2 LESIA, Observatoire de Paris, PSL Research University , CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, Meudon, France
- 3 Virtual Planetary Laboratory, University of Washington , Seattle, Washington
| | - Peter Gao
- 4 Department of Astronomy, University of California Berkeley , Berkeley, California
| | - Yuk L Yung
- 1 Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California
- 5 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
| | - Michael J Russell
- 5 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
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Abstract
UNLABELLED The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ mol(-1) to explain the magnitude of the methane spikes, higher than existing laboratory measurements. The second scenario is that microorganisms convert organic matter in the soil to methane when they are in liquid solutions. This scenario does not require regolith adsorption but entails extant life on Mars. The third scenario is that deep subsurface aquifers produce the bursts of methane. Continued in situ measurements of methane and water, as well as laboratory studies of adsorption and deliquescence, will test these hypotheses and inform the existence of the near-surface reservoir and its exchange with the atmosphere. KEY WORDS Mars-Methane-Astrobiology-Regolith. Astrobiology 16, 539-550.
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Affiliation(s)
- Renyu Hu
- 1 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
- 2 Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California
| | - A Anthony Bloom
- 1 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
| | - Peter Gao
- 2 Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California
| | - Charles E Miller
- 1 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
| | - Yuk L Yung
- 1 Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California
- 2 Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California
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Gladstone GR, Stern SA, Ennico K, Olkin CB, Weaver HA, Young LA, Summers ME, Strobel DF, Hinson DP, Kammer JA, Parker AH, Steffl AJ, Linscott IR, Parker JW, Cheng AF, Slater DC, Versteeg MH, Greathouse TK, Retherford KD, Throop H, Cunningham NJ, Woods WW, Singer KN, Tsang CCC, Schindhelm E, Lisse CM, Wong ML, Yung YL, Zhu X, Curdt W, Lavvas P, Young EF, Tyler GL, Bagenal F, Grundy WM, McKinnon WB, Moore JM, Spencer JR, Andert T, Andrews J, Banks M, Bauer B, Bauman J, Barnouin OS, Bedini P, Beisser K, Beyer RA, Bhaskaran S, Binzel RP, Birath E, Bird M, Bogan DJ, Bowman A, Bray VJ, Brozovic M, Bryan C, Buckley MR, Buie MW, Buratti BJ, Bushman SS, Calloway A, Carcich B, Conard S, Conrad CA, Cook JC, Cruikshank DP, Custodio OS, Ore CMD, Deboy C, Dischner ZJB, Dumont P, Earle AM, Elliott HA, Ercol J, Ernst CM, Finley T, Flanigan SH, Fountain G, Freeze MJ, Green JL, Guo Y, Hahn M, Hamilton DP, Hamilton SA, Hanley J, Harch A, Hart HM, Hersman CB, Hill A, Hill ME, Holdridge ME, Horanyi M, Howard AD, Howett CJA, Jackman C, Jacobson RA, Jennings DE, Kang HK, Kaufmann DE, Kollmann P, Krimigis SM, Kusnierkiewicz D, Lauer TR, Lee JE, Lindstrom KL, Lunsford AW, Mallder VA, Martin N, McComas DJ, McNutt RL, Mehoke D, Mehoke T, Melin ED, Mutchler M, Nelson D, Nimmo F, Nunez JI, Ocampo A, Owen WM, Paetzold M, Page B, Pelletier F, Peterson J, Pinkine N, Piquette M, Porter SB, Protopapa S, Redfern J, Reitsema HJ, Reuter DC, Roberts JH, Robbins SJ, Rogers G, Rose D, Runyon K, Ryschkewitsch MG, Schenk P, Sepan B, Showalter MR, Soluri M, Stanbridge D, Stryk T, Szalay JR, Tapley M, Taylor A, Taylor H, Umurhan OM, Verbiscer AJ, Versteeg MH, Vincent M, Webbert R, Weidner S, Weigle GE, White OL, Whittenburg K, Williams BG, Williams K, Williams S, Zangari AM, Zirnstein E. The atmosphere of Pluto as observed by New Horizons. Science 2016; 351:aad8866. [PMID: 26989258 DOI: 10.1126/science.aad8866] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- G. Randall Gladstone
- Southwest Research Institute, San Antonio, TX 78238, USA
- University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - S. Alan Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - Kimberly Ennico
- National Aeronautics and Space Administration, Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | | | - Harold A. Weaver
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | | | | | - David P. Hinson
- Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA
| | | | | | | | | | | | - Andrew F. Cheng
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | | | | | - Kurt D. Retherford
- Southwest Research Institute, San Antonio, TX 78238, USA
- University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Henry Throop
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | | | | | | | | - Carey M. Lisse
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - Yuk L. Yung
- California Institute of Technology, Pasadena, CA 91125, USA
| | - Xun Zhu
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - Werner Curdt
- Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany
| | - Panayotis Lavvas
- Groupe de Spectroscopie Moléculaire et Atmosphérique, Université Reims Champagne-Ardenne, 51687 Reims, France
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Zhang X, West RA, Irwin PGJ, Nixon CA, Yung YL. Aerosol influence on energy balance of the middle atmosphere of Jupiter. Nat Commun 2015; 6:10231. [PMID: 26694318 PMCID: PMC4703888 DOI: 10.1038/ncomms10231] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/18/2015] [Indexed: 11/09/2022] Open
Abstract
Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5-10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter.
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Affiliation(s)
- Xi Zhang
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Robert A West
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, USA
| | - Patrick G J Irwin
- Atmospheric, Oceanic and Planetary Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK
| | - Conor A Nixon
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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Hu R, Kass DM, Ehlmann BL, Yung YL. Tracing the fate of carbon and the atmospheric evolution of Mars. Nat Commun 2015; 6:10003. [PMID: 26600077 PMCID: PMC4673500 DOI: 10.1038/ncomms10003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/26/2015] [Indexed: 11/18/2022] Open
Abstract
The climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements of the atmosphere. Here we show that a family of solutions exist, invoking no missing reservoirs or loss processes. Escape of carbon via CO photodissociation and sputtering enriches heavy carbon (13C) in the Martian atmosphere, partially compensated by moderate carbonate precipitation. The current atmospheric 13C/12C and rock and soil carbonate measurements indicate an early atmosphere with a surface pressure <1 bar. Only scenarios with large amounts of carbonate formation in open lakes permit higher values up to 1.8 bar. The evolutionary scenarios are fully testable with data from the MAVEN mission and further studies of the isotopic composition of carbonate in the Martian rock record through time. Mars likely evolved from a warmer, wetter early state to the cold, arid current climate, but this evolution is not reflected in recent observations and measurements. Here, the authors derive quantitative constraints on the atmospheric pressure through time, identifying a mechanism that explains the carbon data.
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Affiliation(s)
- Renyu Hu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - David M Kass
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Bethany L Ehlmann
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - Yuk L Yung
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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Wang S, Li KF, Pongetti TJ, Sander SP, Yung YL, Liang MC, Livesey NJ, Santee ML, Harder JW, Snow M, Mills FP. Midlatitude atmospheric OH response to the most recent 11-y solar cycle. Proc Natl Acad Sci U S A 2013; 110:2023-8. [PMID: 23341617 PMCID: PMC3568342 DOI: 10.1073/pnas.1117790110] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hydroxyl radical (OH) plays an important role in middle atmospheric photochemistry, particularly in ozone (O(3)) chemistry. Because it is mainly produced through photolysis and has a short chemical lifetime, OH is expected to show rapid responses to solar forcing [e.g., the 11-y solar cycle (SC)], resulting in variabilities in related middle atmospheric O(3) chemistry. Here, we present an effort to investigate such OH variability using long-term observations (from space and the surface) and model simulations. Ground-based measurements and data from the Microwave Limb Sounder on the National Aeronautics and Space Administration's Aura satellite suggest an ∼7-10% decrease in OH column abundance from solar maximum to solar minimum that is highly correlated with changes in total solar irradiance, solar Mg-II index, and Lyman-α index during SC 23. However, model simulations using a commonly accepted solar UV variability parameterization give much smaller OH variability (∼3%). Although this discrepancy could result partially from the limitations in our current understanding of middle atmospheric chemistry, recently published solar spectral irradiance data from the Solar Radiation and Climate Experiment suggest a solar UV variability that is much larger than previously believed. With a solar forcing derived from the Solar Radiation and Climate Experiment data, modeled OH variability (∼6-7%) agrees much better with observations. Model simulations reveal the detailed chemical mechanisms, suggesting that such OH variability and the corresponding catalytic chemistry may dominate the O(3) SC signal in the upper stratosphere. Continuing measurements through SC 24 are required to understand this OH variability and its impacts on O(3) further.
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Affiliation(s)
- Shuhui Wang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
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Trainer MG, Jimenez JL, Yung YL, Toon OB, Tolbert MA. Nitrogen incorporation in CH(4)-N(2) photochemical aerosol produced by far ultraviolet irradiation. Astrobiology 2012; 12:315-26. [PMID: 22519972 PMCID: PMC3330558 DOI: 10.1089/ast.2011.0754] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Nitrile incorporation into Titan aerosol accompanying hydrocarbon chemistry is thought to be driven by extreme UV wavelengths (λ<120 nm) or magnetospheric electrons in the outer reaches of the atmosphere. Far UV radiation (120-200 nm), which is transmitted down to the stratosphere of Titan, is expected to affect hydrocarbon chemistry only and not initiate the formation of nitrogenated species. We examined the chemical properties of photochemical aerosol produced at far UV wavelengths, using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), which allows for elemental analysis of particle-phase products. Our results show that aerosol formed from CH(4)/N(2) photochemistry contains a surprising amount of nitrogen, up to 16% by mass, a result of photolysis in the far UV. The proportion of nitrogenated organics to hydrocarbon species is shown to be correlated with that of N(2) in the irradiated gas. The aerosol mass greatly decreases when N(2) is removed, which indicates that N(2) plays a major role in aerosol production. Because direct dissociation of N(2) is highly improbable given the immeasurably low cross section at the wavelengths studied, the chemical activation of N(2) must occur via another pathway. Any chemical activation of N(2) at wavelengths >120 nm is presently unaccounted for in atmospheric photochemical models. We suggest that reaction with CH radicals produced from CH(4) photolysis may provide a mechanism for incorporating N into the molecular structure of the aerosol. Further work is needed to understand the chemistry involved, as these processes may have significant implications for how we view prebiotic chemistry on early Earth and similar planets.
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Abstract
Carbon dioxide (CO(2)) is the most important anthropogenic greenhouse gas in the present-day climate. Most of the community focuses on its long-term (decadal to centennial) behaviors that are relevant to climate change, but there are relatively few discussions of its higher-frequency forms of variability, and none regarding its subseasonal distribution. In this work, we report a large-scale intraseasonal variation in the Atmospheric Infrared Sounder CO(2) data in the global tropical region associated with the Madden-Julian oscillation (MJO). The peak-to-peak amplitude of the composite MJO modulation is ∼1 ppmv, with a standard error of the composite mean < 0.1 ppmv. The correlation structure between CO(2) and rainfall and vertical velocity indicate positive (negative) anomalies in CO(2) arise due to upward (downward) large-scale vertical motions in the lower troposphere associated with the MJO. These findings can help elucidate how faster processes can organize, transport, and mix CO(2) and provide a robustness test for coupled carbon-climate models.
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Affiliation(s)
- King-Fai Li
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125; and
| | - Baijun Tian
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Duane E. Waliser
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
| | - Yuk L. Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125; and
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Abstract
Reactions between nitrogen and water in the air surrounding lightning discharges can provide an important source of nitric oxide even under conditions where oxygen is a minor atmospheric constituent. Estimates are given for the associated source of soluble nitrite and nitrate. It is shown that lightning and subsequent atmospheric chemistry can provide a source of nitrate for the primitive ocean as large as 106 tons of nitrogen per year, sufficient to fill the ocean to its present level of nitrate in less than 10(6) years.
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Abstract
It is proposed that Saturn's satellite Titan is covered by an ocean one to several kilometers deep consisting mainly of ethane. If the ocean is in thermodynamic equilibrium with an atmosphere of 3 percent (mole fraction) methane, then its composition is roughly 70 percent ethane, 25 percent methane, and 5 percent nitrogen. Photochemical models predict that ethane is the dominant end product of methane photolysis so that the evolving ocean is both the source and sink for continuing photolysis. The coexisting atmosphere is compatible with Voyager data.
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Yung YL, Liang MC, Jiang X, Shia RL, Lee C, Bézard B, Marcq E. Evidence for carbonyl sulfide (OCS) conversion to CO in the lower atmosphere of Venus. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008je003094] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cheung R, Li KF, Wang S, Pongetti TJ, Cageao RP, Sander SP, Yung YL. Atmospheric hydroxyl radical (OH) abundances from ground-based ultraviolet solar spectra: an improved retrieval method. Appl Opt 2008; 47:6277-6284. [PMID: 19023394 DOI: 10.1364/ao.47.006277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The Fourier Transform Ultraviolet Spectrometer (FTUVS) instrument has recorded a long-term data record of the atmospheric column abundance of the hydroxyl radical (OH) using the technique of high resolution solar absorption spectroscopy. We report new efforts in improving the precision of the OH measurements in order to better model the diurnal, seasonal, and interannual variability of odd hydrogen (HO(x)) chemistry in the stratosphere, which, in turn, will improve our understanding of ozone chemistry and its long-term changes. Until the present, the retrieval method has used a single strong OH absorption line P(1)(1) in the near-ultraviolet at 32,341 cm(-1). We describe a new method that uses an average based on spectral fits to multiple lines weighted by line strength and fitting precision. We have also made a number of improvements in the ability to fit a model to the spectral feature, which substantially reduces the scatter in the measurements of OH abundances.
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Affiliation(s)
- Ross Cheung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
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Parkinson CD, Liang MC, Yung YL, Kirschivnk JL. Habitability of enceladus: planetary conditions for life. ORIGINS LIFE EVOL B 2008; 38:355-69. [PMID: 18566911 DOI: 10.1007/s11084-008-9135-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Accepted: 04/10/2008] [Indexed: 12/01/2022]
Abstract
The prolific activity and presence of a plume on Saturn's tiny moon Enceladus offers us a unique opportunity to sample the interior composition of an icy satellite, and to look for interesting chemistry and possible signs of life. Based on studies of the potential habitability of Jupiter's moon Europa, icy satellite oceans can be habitable if they are chemically mixed with the overlying ice shell on Myr time scales. We hypothesize that Enceladus' plume, tectonic processes, and possible liquid water ocean may create a complete and sustainable geochemical cycle that may allow it to support life. We discuss evidence for surface/ocean material exchange on Enceladus based on the amounts of silicate dust material present in the Enceladus' plume particles. Microphysical cloud modeling of Enceladus' plume shows that the particles originate from a region of Enceladus' near surface where the temperature exceeds 190 K. This could be consistent with a shear-heating origin of Enceladus' tiger stripes, which would indicate extremely high temperatures ( approximately 250-273 K) in the subsurface shear fault zone, leading to the generation of subsurface liquid water, chemical equilibration between surface and subsurface ices, and crustal recycling on a time scale of 1 to 5 Myr. Alternatively, if the tiger stripes form in a mid-ocean-ridge-type mechanism, a half-spreading rate of 1 m/year is consistent with the observed regional heat flux of 250 mW m(-2) and recycling of south polar terrain crust on a 1 to 5 Myr time scale as well.
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Affiliation(s)
- Christopher D Parkinson
- Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
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Tian B, Waliser DE, Kahn RA, Li Q, Yung YL, Tyranowski T, Geogdzhayev IV, Mishchenko MI, Torres O, Smirnov A. Does the Madden-Julian Oscillation influence aerosol variability? ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009372] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Natraj V, Boesch H, Spurr RJD, Yung YL. Retrieval ofXCO2from simulated Orbiting Carbon Observatory measurements using the fast linearized R-2OS radiative transfer model. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Su H, Jiang JH, Gu Y, Neelin JD, Kahn BH, Feldman D, Yung YL, Waters JW, Livesey NJ, Santee ML, Read WG. Variations of tropical upper tropospheric clouds with sea surface temperature and implications for radiative effects. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009624] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Affiliation(s)
- Mao‐Chang Liang
- Research Center for Environmental Changes Academia Sinica Taipei Taiwan
- Division of Geological and Planetary Sciences California Institute of Technology Pasadena California USA
| | - Yuk L. Yung
- Division of Geological and Planetary Sciences California Institute of Technology Pasadena California USA
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Abstract
The isotopic composition of long-lived trace molecules provides a window into atmospheric transport and chemistry. Carbon dioxide is a particularly powerful tracer, because its abundance remains >100 parts per million by volume (ppmv) in the mesosphere. Here, we successfully reproduce the isotopic composition of CO(2) in the middle atmosphere, which has not been previously reported. The mass-independent fractionation of oxygen in CO(2) can be satisfactorily explained by the exchange reaction with O((1)D). In the stratosphere, the major source of O((1)D) is O(3) photolysis. Higher in the mesosphere, we discover that the photolysis of (16)O(17)O and (16)O(18)O by solar Lyman-alpha radiation yields O((1)D) 10-100 times more enriched in (17)O and (18)O than that from ozone photodissociation at lower altitudes. This latter source of heavy O((1)D) has not been considered in atmospheric simulations, yet it may potentially affect the "anomalous" oxygen signature in tropospheric CO(2) that should reflect the gross carbon fluxes between the atmosphere and terrestrial biosphere. Additional laboratory and atmospheric measurements are therefore proposed to test our model and validate the use of CO(2) isotopic fractionation as a tracer of atmospheric chemical and dynamical processes.
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Affiliation(s)
- Mao-Chang Liang
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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Mills FP, Esposito LW, Yung YL. Atmospheric composition, chemistry, and clouds. Exploring Venus as a Terrestrial Planet 2007. [DOI: 10.1029/176gm06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Liang MC, Hartman H, Kopp RE, Kirschvink JL, Yung YL. Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis. Proc Natl Acad Sci U S A 2006; 103:18896-9. [PMID: 17138669 PMCID: PMC1672611 DOI: 10.1073/pnas.0608839103] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Indexed: 11/18/2022] Open
Abstract
During Proterozoic time, Earth experienced two intervals with one or more episodes of low-latitude glaciation, which are probable "Snowball Earth" events. Although the severity of the historical glaciations is debated, theoretical "hard Snowball" conditions are associated with the nearly complete shutdown of the hydrological cycle. We show here that, during such long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The photochemical production of hydrogen peroxide has been proposed previously as the primary mechanism for oxidizing the surface of Mars. During a Snowball, hydrogen peroxide could be stored in the ice; it would then be released directly into the ocean and the atmosphere upon melting and could mediate global oxidation events in the aftermath of the Snowball, such as that recorded in the Fe and Mn oxides of the Kalahari Manganese Field, deposited after the Paleoproterozoic low-latitude Makganyene glaciation. Low levels of peroxides and molecular oxygen generated during Archean and earliest Proterozoic non-Snowball glacial intervals could have driven the evolution of oxygen-mediating and -using enzymes and thereby paved the way for the eventual appearance of oxygenic photosynthesis.
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Affiliation(s)
- Mao-Chang Liang
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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Esposito LW, Colwell JE, Larsen K, McClintock WE, Stewart AIF, Hallett JT, Shemansky DE, Ajello JM, Hansen CJ, Hendrix AR, West RA, Keller HU, Korth A, Pryor WR, Reulke R, Yung YL. Ultraviolet Imaging Spectroscopy Shows an Active Saturnian System. Science 2005; 307:1251-5. [PMID: 15604361 DOI: 10.1126/science.1105606] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Neutral oxygen in the saturnian system shows variability, and the total number of oxygen atoms peaks at 4 x 10(34). Saturn's aurora brightens in response to solar-wind forcing, and the auroral spectrum resembles Jupiter's. Phoebe's surface shows variable water-ice content, and the data indicate it originated in the outer solar system. Saturn's rings also show variable water abundance, with the purest ice in the outermost A ring. This radial variation is consistent with initially pure water ice bombarded by meteors, but smaller radial structures may indicate collisional transport and recent renewal events in the past 10(7) to 10(8) years.
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Affiliation(s)
- Larry W Esposito
- University of Colorado, Laboratory for Atmospheric and Space Physics, 234 Innovation Drive, Boulder, CO 80303-7814, USA.
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Jiang X, Jones DBA, Shia R, Waliser DE, Yung YL. Spatial patterns and mechanisms of the quasi-biennial oscillation–annual beat of ozone. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd006055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Limpasuvan V, Hartmann DL, Thompson DWJ, Jeev K, Yung YL. Stratosphere-troposphere evolution during polar vortex intensification. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd006302] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pernice H, Garcia P, Willner H, Francisco JS, Mills FP, Allen M, Yung YL. Laboratory evidence for a key intermediate in the Venus atmosphere: peroxychloroformyl radical. Proc Natl Acad Sci U S A 2004; 101:14007-10. [PMID: 15375212 PMCID: PMC521112 DOI: 10.1073/pnas.0405501101] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
For two decades, the peroxychloroformyl radical, ClC(O)OO, has played a central role in models of the chemical stability of the Venus atmosphere. No confirmation, however, has been possible in the absence of laboratory measurements for ClC(O)OO. We report the isolation of ClC(O)OO in a cryogenic matrix and its infrared and ultraviolet spectral signatures. These experiments show that ClC(O)OO is thermally and photolytically stable in the Venus atmosphere. These experimental discoveries validate the existence of ClC(O)OO, confirm several longstanding model assumptions, and provide a basis for the astronomical search for this important radical species.
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Affiliation(s)
- Holger Pernice
- Fachbereich C-Anorganische Chemie, Universität Wuppertal, Gauss-Strasse 20, D-42119 Wuppertal, Germany
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Abstract
The widespread use of hydrogen fuel cells could have hitherto unknown environmental impacts due to unintended emissions of molecular hydrogen, including an increase in the abundance of water vapor in the stratosphere (plausibly by as much as approximately 1 part per million by volume). This would cause stratospheric cooling, enhancement of the heterogeneous chemistry that destroys ozone, an increase in noctilucent clouds, and changes in tropospheric chemistry and atmosphere-biosphere interactions.
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Affiliation(s)
- Tracey K Tromp
- California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
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Huang XL, Yung YL, Margolis JS. Use of high-resolution measurements for the retrieval of temperature and gas-concentration profiles from outgoing infrared spectra in the presence of cirrus clouds. Appl Opt 2003; 42:2155-2165. [PMID: 12716157 DOI: 10.1364/ao.42.002155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We explore ways in which high-spectral-resolution measurements can aid in the retrieval of atmospheric temperature and gas-concentration profiles from outgoing infrared spectra when optically thin cirrus clouds are present. Simulated outgoing spectra that contain cirrus are fitted with spectra that do not contain cirrus, and the residuals are examined. For those lines with weighting functions that peak near the same altitude as the thin cirrus, unique features are observed in the residuals. These unique features are highly sensitive to the resolution of the instrumental line shape. For thin cirrus these residual features are narrow (< or = 0.1 cm(-1)), so high spectral resolution is required for unambiguous observation. The magnitudes of these unique features are larger than the noise of modern instruments. The sensitivities of these features to cloud height and cloud optical depth are also discussed. Our sensitivity studies show that, when the errors in the estimation of temperature profiles are not large, the dominant contribution to the residuals is the misinterpretation of cirrus. An analysis that focuses on information content is also presented. An understanding of the magnitude of the effect and of its dependence on spectral resolution as well as on spectral region is important for retrieving spacecraft data and for the design of future infrared instruments for forecasting weather and monitoring greenhouse gases.
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Affiliation(s)
- Xianglei L Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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