1
|
Zhang G. Warming-induced contraction of tropical convection delays and reduces tropical cyclone formation. Nat Commun 2023; 14:6274. [PMID: 37805508 PMCID: PMC10560220 DOI: 10.1038/s41467-023-41911-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/19/2023] [Indexed: 10/09/2023] Open
Abstract
The future risk of tropical cyclones (TCs) strongly depends on changes in TC frequency, but models have persistently produced contrasting projections. A satisfactory explanation of the projected changes also remains elusive. Here we show a warming-induced contraction of tropical convection delays and reduces TC formation. This contraction manifests as stronger equatorial convection and weaker off-equatorial convection. It has been robustly projected by climate models, particularly in the northern hemisphere. This contraction shortens TC seasons by delaying the poleward migration of the intertropical convergence zone. At seasonal peaks of TC activity, the equatorial and off-equatorial components of this contraction are associated with TC-hindering environmental changes. Finally, the convection contraction and associated warming patterns can partly explain the ensemble spread in projecting future TC frequency. This study highlights the role of convection contraction and provides motivation for coordinated research to solidify our confidence in future TC risk projections.
Collapse
Affiliation(s)
- Gan Zhang
- Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 1301 W. Green Street, Urbana, IL, 61801, USA.
| |
Collapse
|
2
|
Schiro KA, Su H, Ahmed F, Dai N, Singer CE, Gentine P, Elsaesser GS, Jiang JH, Choi YS, David Neelin J. Model spread in tropical low cloud feedback tied to overturning circulation response to warming. Nat Commun 2022; 13:7119. [DOI: 10.1038/s41467-022-34787-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 11/07/2022] [Indexed: 11/21/2022] Open
Abstract
AbstractAmong models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6), here we show that the magnitude of the tropical low cloud feedback, which contributes considerably to uncertainty in estimates of climate sensitivity, is intimately linked to tropical deep convection and its effects on the tropical atmospheric overturning circulation. First, a reduction in tropical ascent area and an increased frequency of heavy precipitation result in high cloud reduction and upper-tropospheric drying, which increases longwave cooling and reduces subsidence weakening, favoring low cloud reduction (Radiation-Subsidence Pathway). Second, increased longwave cooling decreases tropospheric stability, which also reduces subsidence weakening and low cloudiness (Stability-Subsidence Pathway). In summary, greater high cloud reduction and upper-tropospheric drying (negative longwave feedback) lead to a more positive cloud feedback among CMIP6 models by contributing to a greater reduction in low cloudiness (positive shortwave feedback). Varying strengths of the two pathways contribute considerably to the intermodel spread in climate sensitivity.
Collapse
|
3
|
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 AND SPACE SCIENCE (HOBOKEN, N.J.) 2022; 9:e2022EA002245. [PMID: 35859723 PMCID: PMC9285748 DOI: 10.1029/2022ea002245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
4
|
Ocean surface energy balance allows a constraint on the sensitivity of precipitation to global warming. Nat Commun 2021; 12:2115. [PMID: 33837191 PMCID: PMC8035209 DOI: 10.1038/s41467-021-22406-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 03/11/2021] [Indexed: 11/10/2022] Open
Abstract
Climate models generally predict higher precipitation in a future warmer climate. Whether the precipitation intensification occurred in response to historical warming continues to be a subject of debate. Here, using observations of the ocean surface energy balance as a hydrological constraint, we find that historical warming intensified precipitation at a rate of 0.68 ± 0.51% K−1, which is slightly higher than the multi-model mean calculation for the historical climate (0.38 ± 1.18% K−1). The reduction in ocean surface albedo associated with melting of sea ice is a positive contributor to the precipitation temperature sensitivity. On the other hand, the observed increase in ocean heat storage weakens the historical precipitation. In this surface energy balance framework, the incident shortwave radiation at the ocean surface and the ocean heat storage exert a dominant control on the precipitation temperature sensitivity, explaining 91% of the inter-model spread and the spread across climate scenarios in the Intergovernmental Panel on Climate Change Fifth Assessment Report. There is some disagreement between climate models about how much precipitation changes under global warming. Here, the authors use the ocean surface energy balance to constrain the sensitivity of precipitation to historical warming and find that it is increasing by 0.68 ± 0.51% per degree warming.
Collapse
|
5
|
Tai CY, Chin AL, Chiang AS. Comprehensive map of visual projection neurons for processing ultraviolet information in the Drosophila brain. J Comp Neurol 2020; 529:1988-2013. [PMID: 33174208 PMCID: PMC8049075 DOI: 10.1002/cne.25068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 11/11/2022]
Abstract
The brain perceives visual information and controls behavior depending on its underlying neural circuits. How UV information is represented and processed in the brain remains poorly understood. In Drosophila melanogaster, UV light is detected by the R7 photoreceptor that projects exclusively into the medulla layer 6 (M6 ). Herein, we imaged 28,768 single neurons and identified 238 visual projection neurons linking M6 to the central brain. Based on morphology and connectivity, these visual projection neurons were systematically classified into 94 cell types belonging to 12 families. Three tracts connected M6 in each optic lobe to the central brain: One dorsal tract linking to the ipsilateral lateral anterior optic tubercle (L-AOTU) and two medial tracts linking to the ipsilateral ventral medial protocerebrum (VMP) and the contralateral VMP. The M6 information was primarily represented in the L-AOTU. Each L-AOTU consisted of four columns that each contained three glomeruli. Each L-AOTU glomerulus received inputs from M6 subdomains and gave outputs to a glomerulus within the ellipsoid body dendritic region, suggesting specific processing of spatial information through the dorsal pathway. Furthermore, the middle columns of the L-AOTUs of both hemispheres were connected via the intertubercle tract, suggesting information integration between the two eyes. In contrast, an ascending neuron linked each VMP to all glomeruli in the bulb and the L-AOTU, bilaterally, suggesting general processing of information through the ventral pathway. Altogether, these diverse morphologies of the visual projection neurons suggested multi-dimensional processing of UV information through parallel and bilateral circuits in the Drosophila brain.
Collapse
Affiliation(s)
- Chu-Yi Tai
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan
| | - An-Lun Chin
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
| | - Ann-Shyn Chiang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan.,Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan.,Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.,Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli County, Taiwan.,Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.,Kavli Institute for Brain and Mind, University of California at San Diego, La Jolla, California, USA
| |
Collapse
|
6
|
Allan RP, Barlow M, Byrne MP, Cherchi A, Douville H, Fowler HJ, Gan TY, Pendergrass AG, Rosenfeld D, Swann ALS, Wilcox LJ, Zolina O. Advances in understanding large-scale responses of the water cycle to climate change. Ann N Y Acad Sci 2020; 1472:49-75. [PMID: 32246848 DOI: 10.1111/nyas.14337] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 11/30/2022]
Abstract
Globally, thermodynamics explains an increase in atmospheric water vapor with warming of around 7%/°C near to the surface. In contrast, global precipitation and evaporation are constrained by the Earth's energy balance to increase at ∼2-3%/°C. However, this rate of increase is suppressed by rapid atmospheric adjustments in response to greenhouse gases and absorbing aerosols that directly alter the atmospheric energy budget. Rapid adjustments to forcings, cooling effects from scattering aerosol, and observational uncertainty can explain why observed global precipitation responses are currently difficult to detect but are expected to emerge and accelerate as warming increases and aerosol forcing diminishes. Precipitation increases with warming are expected to be smaller over land than ocean due to limitations on moisture convergence, exacerbated by feedbacks and affected by rapid adjustments. Thermodynamic increases in atmospheric moisture fluxes amplify wet and dry events, driving an intensification of precipitation extremes. The rate of intensification can deviate from a simple thermodynamic response due to in-storm and larger-scale feedback processes, while changes in large-scale dynamics and catchment characteristics further modulate the frequency of flooding in response to precipitation increases. Changes in atmospheric circulation in response to radiative forcing and evolving surface temperature patterns are capable of dominating water cycle changes in some regions. Moreover, the direct impact of human activities on the water cycle through water abstraction, irrigation, and land use change is already a significant component of regional water cycle change and is expected to further increase in importance as water demand grows with global population.
Collapse
Affiliation(s)
- Richard P Allan
- Department of Meteorology and National Centre for Earth Observation, University of Reading, Reading, United Kingdom
| | - Mathew Barlow
- Department of Environmental Earth and Atmospheric Sciences, University of Massachusetts Lowell, Lowell, Massachusetts
| | - Michael P Byrne
- School of Earth and Environmental Science, University of St Andrews, St Andrews, United Kingdom.,Department of Physics, University of Oxford, Oxford, United Kingdom
| | - Annalisa Cherchi
- Istituto Nazionale di Geofisica e Vulcanologia Sezione di Bologna, INGV, Bologna, Italy
| | - Hervé Douville
- Centre National de Recherches Météorologiques, Météo-France/CNRS, Toulouse, France
| | - Hayley J Fowler
- University of Newcastle, Newcastle upon Tyne, United Kingdom
| | - Thian Y Gan
- University of Alberta, Edmonton, Alberta, Canada
| | | | - Daniel Rosenfeld
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,School of Atmospheric Sciences, Nanjing University, Nanjing, China
| | | | - Laura J Wilcox
- National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading, United Kingdom
| | - Olga Zolina
- L'Institut des Géosciences de l'Environnement/Centre National de la Recherche Scientifique, L'Université Grenoble Alpes, Grenoble, France.,P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
7
|
Yue Q, Jiang JH, Heymsfield A, Liou K, Gu Y, Sinha A. Combining In Situ and Satellite Observations to Understand the Vertical Structure of Tropical Anvil Cloud Microphysical Properties During the TC4 Experiment. EARTH AND SPACE SCIENCE (HOBOKEN, N.J.) 2020; 7:e2020EA001147. [PMID: 32715026 PMCID: PMC7375154 DOI: 10.1029/2020ea001147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/06/2020] [Accepted: 03/14/2020] [Indexed: 06/11/2023]
Abstract
Tropical anvil clouds have a profound impact on Earth's weather and climate. Their role in Earth's energy balance and hydrologic cycle is heavily modulated by the vertical structure of the microphysical properties for various hydrometeors in these clouds and their dependence on the ambient environmental conditions. Accurate representations of the variability and covariability of such vertical structures are key to both the satellite remote sensing of cloud and precipitation and numerical modeling of weather and climate, which remain a challenge. This study presents a new method to combine vertically resolved observations from CloudSat radar reflectivity and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation cloud masks with probability distributions of cloud microphysical properties and the ambient atmospheric conditions from detailed in situ measurements on tropical anvils sampled during the National Aeronautics and Space Administration TC4 (Tropical Composition, Cloud and Climate Coupling) mission. We focus on the microphysical properties of the vertical distribution of ice water content, particle size distributions, and effective sizes for different hydrometeors, including ice particles and supercooled liquid droplets. Results from this method are compared with those from in situ data alone and various CloudSat/Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation cloud retrievals. The sampling limitation of the field experiment and algorithm limitations in the current retrievals is highlighted, especially for the liquid cloud particles, while a generally good agreement with ice cloud microphysical properties is seen from different methods. While the method presented in this study is applied to tropical anvil clouds observed during TC4, it can be readily employed to study a broad range of ice clouds sampled by various field campaigns.
Collapse
Affiliation(s)
- Qing Yue
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Jonathan H. Jiang
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Andrew Heymsfield
- Mesoscale and Microscale MeteorologyNational Center for Atmospheric ResearchBoulderCOUSA
| | - Kuo‐Nan Liou
- Department of Atmospheric and Oceanic Sciences and Joint Institute for Regional Earth System Science and EngineeringUniversity of CaliforniaLos AngelesCAUSA
| | - Yu Gu
- Department of Atmospheric and Oceanic Sciences and Joint Institute for Regional Earth System Science and EngineeringUniversity of CaliforniaLos AngelesCAUSA
| | - Arushi Sinha
- Department of Atmospheric and Oceanic Sciences and Joint Institute for Regional Earth System Science and EngineeringUniversity of CaliforniaLos AngelesCAUSA
| |
Collapse
|
8
|
Tang S, Ruan H, Feng R, Zhao Y, Tan G, Zhang L, Wang X. Tunable Reduction of 2,4,6‐Tri(4‐pyridyl)‐1,3,5‐Triazine: From Radical Anion to Diradical Dianion to Radical Metal–Organic Framework. Angew Chem Int Ed Engl 2019; 58:18224-18229. [DOI: 10.1002/anie.201910468] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/19/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Shuxuan Tang
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Huapeng Ruan
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Rui Feng
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Yue Zhao
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Gengwen Tan
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Li Zhang
- Center of Materials Science and EngineeringGuangxi University of Science and Technology Liuzhou 545006 China
| | - Xinping Wang
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| |
Collapse
|
9
|
Zhang Q, Shen Z, Xu CY, Sun P, Hu P, He C. A new statistical downscaling approach for global evaluation of the CMIP5 precipitation outputs: Model development and application. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:1048-1067. [PMID: 31470471 DOI: 10.1016/j.scitotenv.2019.06.310] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 06/10/2023]
Abstract
Outputs of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models have been widely used in studies of climate changes related to scenarios at global and regional scales. However, CMIP5 outputs cannot be used directly in analysis of climate changes due to coarse spatial resolution. Here, we proposed a new statistical downscaling method for the downscaling practice of the CMIP5 outputs, i.e. Bias-corrected and station-based Non-linear Regression Downscaling method based on Randomly-Moving Points (BNRD). And up to now, there are only two global downscaled CMIP5 precipitation datasets, i.e. NASA daily downscaled CMIP5 precipitation product and BCSD-based (Bias Correction Spatial Disaggregation) monthly downscaled CMIP5 precipitation product available online, which are both based on BCSD downscaling method. Hence, we evaluated downscaling performance of BNRD by comparing it with the downscaled CMIP5 outputs using the BCSD method in this current study. The results indicate that: (1) during the period for development of the model (1964-2005), the error between downscaled CMIP5 precipitation and GPCC ranges between -50 mm-50 mm at monthly scale. When compared to BCSD-downscaled CMIP5 precipitation, BNRD-downscaled CMIP5 precipitation well reduces errors and avoids underestimation and overestimation of GPCC by BCSD-downscaled CMIP5 precipitation; (2) during period for verification of the downscaling models (2006-2013), the maximum (182 mm), minimum (15 mm) and average (68 mm) RMSEs between BNRD-downscaled CMIP5 precipitation and GPCC are all lower than those between BCSD-downscaled CMIP5 precipitation and GPCC at continental scales. Besides, from the average precipitation viewpoint, BNRD-downscaled CMIP5 precipitation is in higher correlation (around 0.75) with GPCC than BCSD-downscaled CMIP5 precipitation under RCP4.5 and RCP8.5 scenarios at continental scales; (3) BNRD resolved the negative relation to GPCC in the areas near equator, including north part of the South America, southern Africa, northern Australia. In all, BNRD downscaling method developed in this study performs better in describing GPCC changes in both space and time when compared to BCSD and can be used for downscaling practice of CMIP5 and even potentially CMIP6 precipitation outputs over the globe.
Collapse
Affiliation(s)
- Qiang Zhang
- Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China; Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Ministry of Education/Ministry of Civil Affairs, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing Normal University, Beijing 100875, China.
| | - Zexi Shen
- Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China; Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Ministry of Education/Ministry of Civil Affairs, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing Normal University, Beijing 100875, China.
| | - Chong-Yu Xu
- Department of Geosciences and Hydrology, University of Oslo, P O Box 1047, Blindern, N-0316 Oslo, Norway
| | - Peng Sun
- College of Territorial Resource and Tourism, Anhui Normal University, Anhui 241002, China
| | - Pan Hu
- Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China; Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Ministry of Education/Ministry of Civil Affairs, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Earth Surface Processes and Resources Ecology, Beijing Normal University, Beijing 100875, China
| | - Chunyang He
- Center for Human-Environment System Sustainability (CHESS), State Key Laboratory of Earth Surface Processes and Resource Ecology (ESPRE), Beijing Normal University, Beijing 100875, China
| |
Collapse
|
10
|
Tang S, Ruan H, Feng R, Zhao Y, Tan G, Zhang L, Wang X. Tunable Reduction of 2,4,6‐Tri(4‐pyridyl)‐1,3,5‐Triazine: From Radical Anion to Diradical Dianion to Radical Metal–Organic Framework. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201910468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shuxuan Tang
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Huapeng Ruan
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Rui Feng
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Yue Zhao
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Gengwen Tan
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| | - Li Zhang
- Center of Materials Science and EngineeringGuangxi University of Science and Technology Liuzhou 545006 China
| | - Xinping Wang
- State Key Laboratory of Coordination ChemistryJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing University Nanjing 210023 China
| |
Collapse
|
11
|
Surface and tropospheric ozone trends in the Southern Hemisphere since 1990: possible linkages to poleward expansion of the Hadley circulation. Sci Bull (Beijing) 2019; 64:400-409. [PMID: 36659731 DOI: 10.1016/j.scib.2018.12.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/12/2018] [Accepted: 12/14/2018] [Indexed: 01/21/2023]
Abstract
Increases in free tropospheric ozone over the past two decades are mainly in the Northern Hemisphere that have been widely documented, while ozone trends in the Southern Hemisphere (SH) remain largely unexplained. Here we first show that in-situ and satellite observations document increases of tropospheric ozone in the SH over 1990-2015. We then use a global chemical transport model to diagnose drivers of these trends. We find that increases of anthropogenic emissions (including methane) are not the most significant contributors. Instead, we explain the trend as due to changes in meteorology, and particularly in transport patterns. We propose a possible linkage of the ozone increases to meridional transport pattern shifts driven by poleward expansion of the SH Hadley circulation (SHHC). The SHHC poleward expansion allows more downward transport of ozone from the stratosphere to the troposphere at higher latitudes, and also enhances tropospheric ozone production through stronger lifting of tropical ozone precursors to the upper troposphere. These together may lead to increasing tropospheric ozone in the extratropical SH, particularly in the middle/upper troposphere and in austral autumn. Poleward expansion of the Hadley circulation is partly driven by greenhouse warming, and the associated increase in tropospheric ozone potentially provides a positive climate feedback amplifying the warming that merits further quantification.
Collapse
|
12
|
Using the Himawari-8 AHI Multi-Channel to Improve the Calculation Accuracy of Outgoing Longwave Radiation at the Top of the Atmosphere. REMOTE SENSING 2019. [DOI: 10.3390/rs11050589] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, Himawari-8 Advanced Himawari Imager (AHI) longwave channel data that is sensitive to clouds and absorption gas were used to improve the accuracy of the algorithm used to calculate outgoing longwave radiation (OLR) at the top of the atmosphere. A radiative transfer model with a variety of atmospheric conditions was run using Garand vertical profile data as input data. The results of the simulation showed that changes in AHI channels 8, 12, 15, and 16, which were used to calculate OLR, were sensitive to changes in cloud characteristics (cloud optical thickness and cloud height) and absorption gases (water vapor, O3, CO2, aerosol optical thickness) in the atmosphere. When compared to long-term analysis OLR data from 2017, as recorded by the Cloud and Earth’s Radiant Energy System (CERES), the OLR calculated in this study had an annual mean bias of 2.28 Wm−2 and a root mean square error (RMSE) of 11.03 Wm−2. The new calculation method mitigated the problem of overestimations in OLR in mostly cloudy and overcast regions and underestimated OLR in cloud-free desert regions. It is also an improvement over the result from the existing OLR calculation algorithm, which uses window and water vapor channels.
Collapse
|
13
|
Regulation of atmospheric circulation controlling the tropical Pacific precipitation change in response to CO 2 increases. Nat Commun 2019; 10:1108. [PMID: 30846694 PMCID: PMC6405775 DOI: 10.1038/s41467-019-08913-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 01/22/2019] [Indexed: 11/08/2022] Open
Abstract
The spatial pattern of precipitation responses to CO2 concentration increases significantly influences global weather and climate variability by altering the location of tropical heating in a warmer climate. In this study, we analyze the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model projections of tropical Pacific rainfall response to quadrupled increase of CO2. We found that the precipitation changes to the CO2 concentration increase cannot be interpreted by a weakening or strengthening of large-scale east-west coupling across the tropical Pacific basin, i.e., Walker circulation. By calculating the water vapor transport, we suggest instead that different responses of the Walker and Hadley circulations to the increasing CO2 concentration shape the details of the spatial pattern of precipitation in the tropical Pacific. Therefore, more regionally perturbed circulations over the tropical Pacific, which is influenced by the mean state change in the tropical Pacific and the enhanced precipitation outside the tropical Pacific, lead to greater increases in precipitation in the western equatorial Pacific as compared to the eastern tropical Pacific in a warmer climate.
Collapse
|
14
|
Byrne MP, Pendergrass AG, Rapp AD, Wodzicki KR. Response of the Intertropical Convergence Zone to Climate Change: Location, Width, and Strength. CURRENT CLIMATE CHANGE REPORTS 2018; 4:355-370. [PMID: 30931244 PMCID: PMC6411165 DOI: 10.1007/s40641-018-0110-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
PURPOSE OF REVIEW The intertropical convergence zone (ITCZ) is a planetary-scale band of heavy precipitation close to the equator. Here, we consider the response of the ITCZ structure to climate change using observations, simulations, and theory. We focus on the substantial yet underappreciated projected changes in ITCZ width and strength, and highlight an emerging conceptual framework for understanding these changes. RECENT FINDINGS Satellite observations and reanalysis data show a narrowing and strengthening of precipitation in the ITCZ over recent decades in both the Atlantic and Pacific basins, but little change in ITCZ location. Consistent with observations, coupled climate models predict no robust change in the zonal-mean ITCZ location over the twenty-first century. However, the majority of models project a narrowing of the ITCZ and weakening mean ascent. Interestingly, changes in ITCZ width and strength are strongly anti-correlated across models. SUMMARY The ITCZ has narrowed over recent decades yet its location has remained approximately constant. Climate models project further narrowing and a weakening of the average ascent within the ITCZ as the climate continues to warm. Following intense work over the last ten years, the physical mechanisms controlling the ITCZ location are now well understood. The development of complementary theories for ITCZ width and strength is a current research priority. Outstanding challenges include understanding the ITCZ response to past climate changes and over land versus ocean regions, and better constraining all aspects of the ITCZ structure in model projections. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (10.1007/s40641-018-0110-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Michael P. Byrne
- Space and Atmospheric Physics Group, Imperial College London, London, SW7 2AZ UK
| | | | | | | |
Collapse
|
15
|
Jiang JH, Yue Q, Su H, Reising SC, Kangaslahti PP, Deal WR, Schlecht ET, Wu L, Evans KF. A simulation of ice cloud particle size, humidity, and temperature measurements from the TWICE CubeSat. EARTH AND SPACE SCIENCE (HOBOKEN, N.J.) 2017; 4:574-587. [PMID: 29104900 PMCID: PMC5656330 DOI: 10.1002/2017ea000296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/07/2017] [Accepted: 07/20/2017] [Indexed: 06/07/2023]
Abstract
This paper describes a forward radiative transfer model and retrieval system (FMRS) for the Tropospheric Water and cloud ICE (TWICE) CubeSat instrument. We use the FMRS to simulate radiances for the TWICE's 14 millimeter- and submillimeter-wavelength channels for a tropical atmospheric state produced by a Weather Research and Forecasting model simulation. We also perform simultaneous retrievals of cloud ice particle size, ice water content (IWC), water vapor content (H2O), and temperature from the simulated TWICE radiances using the FMRS. We show that the TWICE instrument is capable of retrieving ice particle size in the range of ~50-1000 μm in mass mean effective diameter with approximately 50% uncertainty. The uncertainties of other retrievals from TWICE are about 1 K for temperature, 50% for IWC, and 20% for H2O.
Collapse
Affiliation(s)
- Jonathan H. Jiang
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Qing Yue
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Hui Su
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Steven C. Reising
- Microwave Systems LaboratoryColorado State UniversityFort CollinsColoradoUSA
| | - Pekka P. Kangaslahti
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | | | - Erich T. Schlecht
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Longtao Wu
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - K. Franklin Evans
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderColoradoUSA
| |
Collapse
|