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Haspel C, Cohen I. The SSSS scheme: a method for calculating multiple scattering of electromagnetic radiation by a collection of sparsely spaced spherical scatterers of Mie-scattering size based on first principles. APPLIED OPTICS 2022; 61:8563-8577. [PMID: 36255988 DOI: 10.1364/ao.465701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/30/2022] [Indexed: 06/16/2023]
Abstract
We present a method for calculating multiple scattering of electromagnetic radiation by a collection of sparsely spaced spherical scatterers (SSSS) of Mie-scattering size based on first principles rather than radiative transfer theory. In this respect, our methodology is conceptually similar to the superposition T-matrix method. However, our implementation, which we call the SSSS scheme, differs in a number of respects. Overall, the SSSS scheme is simpler, it is better suited numerically to sparse spacing, and the computer memory required is only linearly dependent on the total number of scatterers. We suggest that the SSSS scheme would be particularly useful for examining the effects of different spatial configurations of drops within water clouds in Earth's atmosphere and would also be useful in other fields of research in which the exact configuration of a collection of sparsely spaced Mie-sized scatterers is important.
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Shen Z, Ming Y, Held IM. Using the fast impact of anthropogenic aerosols on regional land temperature to constrain aerosol forcing. SCIENCE ADVANCES 2020; 6:eabb5297. [PMID: 32821838 PMCID: PMC7406383 DOI: 10.1126/sciadv.abb5297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/24/2020] [Indexed: 06/01/2023]
Abstract
Anthropogenic aerosols have been postulated to have a cooling effect on climate, but its magnitude remains uncertain. Using atmospheric general circulation model simulations, we separate the land temperature response into a fast response to radiative forcings and a slow response to changing oceanic conditions and find that the former accounts for about one fifth of the observed warming of the Northern Hemisphere land during summer and autumn since the 1960s. While small, this fast response can be constrained by observations. Spatially varying aerosol effects can be detected on the regional scale, specifically warming over Europe and cooling over Asia. These results provide empirical evidence for the important role of aerosols in setting regional land temperature trends and point to an emergent constraint that suggests strong global aerosol forcing and high transient climate response.
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Affiliation(s)
- Zhaoyi Shen
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yi Ming
- Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, NJ 08540, USA
| | - Isaac M. Held
- Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ 08540, USA
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Abstract
Early climate and weather models, constrained by computing resources, made numerical approximations on modeling the real world. One process, the radiative transfer of sunlight through the atmosphere, has always been a costly component. As computational ability expanded, these models added resolution, processes, and numerical methods to reduce errors and become the Earth system models that we use today. While many of the original approximations have since been improved, one—that the Earth’s surface and atmosphere are locally flat—remains in current models. Correcting from flat to spherical atmospheres leads to regionally differential solar heating at rates comparable to the climate forcing by greenhouse gases and aerosols. In addition, spherical atmospheres change how we evaluate the aerosol direct radiative forcing. Sunlight drives the Earth’s weather, climate, chemistry, and biosphere. Recent efforts to improve solar heating codes in climate models focused on more accurate treatment of the absorption spectrum or fractional clouds. A mostly forgotten assumption in climate models is that of a flat Earth atmosphere. Spherical atmospheres intercept 2.5 W⋅m−2 more sunlight and heat the climate by an additional 1.5 W⋅m−2 globally. Such a systematic shift, being comparable to the radiative forcing change from preindustrial to present, is likely to produce a discernible climate shift that would alter a model’s skill in simulating current climate. Regional heating errors, particularly at high latitudes, are several times larger. Unlike flat atmospheres, constituents in a spherical atmosphere, such as clouds and aerosols, alter the total amount of energy received by the Earth. To calculate the net cooling of aerosols in a spherical framework, one must count the increases in both incident and reflected sunlight, thus reducing the aerosol effect by 10 to 14% relative to using just the increase in reflected. Simple fixes to the current flat Earth climate models can correct much of this oversight, although some inconsistencies will remain.
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Westervelt DM, Conley AJ, Fiore AM, Lamarque JF, Shindell D, Previdi M, Faluvegi G, Correa G, Horowitz LW. Multimodel precipitation responses to removal of U.S. sulfur dioxide emissions. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2017; 122:5024-5038. [PMID: 33005557 PMCID: PMC7526610 DOI: 10.1002/2017jd026756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Emissions of aerosols and their precursors are declining due to policies enacted to protect human health, yet we currently lack a full understanding of the magnitude, spatiotemporal pattern, statistical significance, and physical mechanisms of precipitation responses to aerosol reductions. We quantify the global and regional precipitation responses to U.S. SO2 emission reductions using three fully coupled chemistry-climate models: Community Earth System Model version 1, Geophysical Fluid Dynamics Laboratory Coupled Model 3, and Goddard Institute for Space Studies ModelE2. We contrast 200 year (or longer) simulations in which anthropogenic U.S. sulfur dioxide (SO2) emissions are set to zero with present-day control simulations to assess the aerosol, cloud, and precipitation response to U.S. SO2 reductions. In all three models, reductions in aerosol optical depth up to 70% and cloud droplet number column concentration up to 60% occur over the eastern U.S. and extend over the Atlantic Ocean. Precipitation responses occur both locally and remotely, with the models consistently showing an increase in most regions considered. We find a northward shift of the tropical rain belt location of up to 0.35° latitude especially near the Sahel, where the rainy season length and intensity are significantly enhanced in two of the three models. This enhancement is the result of greater warming in the Northern versus Southern Hemispheres, which acts to shift the Intertropical Convergence Zone northward, delivering additional wet season rainfall to the Sahel. Two of our three models thus imply a previously unconsidered benefit of continued U.S. SO2 reductions for Sahel precipitation.
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Affiliation(s)
- D. M. Westervelt
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
- NASA Goddard Institute for Space Studies, New York, New York, USA
| | - A. J. Conley
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - A. M. Fiore
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
- Department of Earth and Environmental Sciences, Columbia University, Palisades, New York, USA
| | - J.-F. Lamarque
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - D. Shindell
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - M. Previdi
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
| | - G. Faluvegi
- NASA Goddard Institute for Space Studies, New York, New York, USA
- Center for Climate Systems Research, Columbia University, New York, New York, USA
| | - G. Correa
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
| | - L. W. Horowitz
- Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, New Jersey, USA
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DIFFERENCES IN WATER VAPOR RADIATIVE TRANSFER AMONG 1D MODELS CAN SIGNIFICANTLY AFFECT THE INNER EDGE OF THE HABITABLE ZONE. ACTA ACUST UNITED AC 2016. [DOI: 10.3847/0004-637x/826/2/222] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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DeAngelis AM, Qu X, Zelinka MD, Hall A. An observational radiative constraint on hydrologic cycle intensification. Nature 2016; 528:249-53. [PMID: 26659186 DOI: 10.1038/nature15770] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/25/2015] [Indexed: 11/09/2022]
Abstract
Intensification of the hydrologic cycle is a key dimension of climate change, with substantial impacts on human and natural systems. A basic measure of hydrologic cycle intensification is the increase in global-mean precipitation per unit surface warming, which varies by a factor of three in current-generation climate models (about 1-3 per cent per kelvin). Part of the uncertainty may originate from atmosphere-radiation interactions. As the climate warms, increases in shortwave absorption from atmospheric moistening will suppress the precipitation increase. This occurs through a reduction of the latent heating increase required to maintain a balanced atmospheric energy budget. Using an ensemble of climate models, here we show that such models tend to underestimate the sensitivity of solar absorption to variations in atmospheric water vapour, leading to an underestimation in the shortwave absorption increase and an overestimation in the precipitation increase. This sensitivity also varies considerably among models due to differences in radiative transfer parameterizations, explaining a substantial portion of model spread in the precipitation response. Consequently, attaining accurate shortwave absorption responses through improvements to the radiative transfer schemes could reduce the spread in the predicted global precipitation increase per degree warming for the end of the twenty-first century by about 35 per cent, and reduce the estimated ensemble-mean increase in this quantity by almost 40 per cent.
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Affiliation(s)
- Anthony M DeAngelis
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Xin Qu
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Mark D Zelinka
- Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Alex Hall
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, California 90095, USA
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Ocko IB, Ramaswamy V, Ginoux P, Ming Y, Horowitz LW. Sensitivity of scattering and absorbing aerosol direct radiative forcing to physical climate factors. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd018019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Goren T, Rosenfeld D. Satellite observations of ship emission induced transitions from broken to closed cell marine stratocumulus over large areas. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017981] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Freidenreich SM, Ramaswamy V. Analysis of the biases in the downward shortwave surface flux in the GFDL CM2.1 general circulation model. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd014930] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Huang X, Loeb NG, Yang W. Spectrally resolved fluxes derived from collocated AIRS and CERES measurements and their application in model evaluation: 2. Cloudy sky and band-by-band cloud radiative forcing over the tropical oceans. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd013932] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lee SS, Donner LJ, Phillips VTJ, Ming Y. The dependence of aerosol effects on clouds and precipitation on cloud-system organization, shear and stability. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009224] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Huang X, Yang W, Loeb NG, Ramaswamy V. Spectrally resolved fluxes derived from collocated AIRS and CERES measurements and their application in model evaluation: Clear sky over the tropical oceans. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009219] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Fiore AM, West JJ, Horowitz LW, Naik V, Schwarzkopf MD. Characterizing the tropospheric ozone response to methane emission controls and the benefits to climate and air quality. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009162] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ginoux P, Horowitz LW, Ramaswamy V, Geogdzhayev IV, Holben BN, Stenchikov G, Tie X. Evaluation of aerosol distribution and optical depth in the Geophysical Fluid Dynamics Laboratory coupled model CM2.1 for present climate. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006707] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Erlick C, Ramaswamy V, Russell LM. Differing regional responses to a perturbation in solar cloud absorption in the SKYHI general circulation model. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006491] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Huang X, Ramaswamy V, Schwarzkopf MD. Quantification of the source of errors in AM2 simulated tropical clear-sky outgoing longwave radiation. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006576] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Freidenreich SM. Refinement of the Geophysical Fluid Dynamics Laboratory solar benchmark computations and an improved parameterization for climate models. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005471] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Naik V, Mauzerall D, Horowitz L, Schwarzkopf MD, Ramaswamy V, Oppenheimer M. Net radiative forcing due to changes in regional emissions of tropospheric ozone precursors. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd005908] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Halthore RN. Intercomparison of shortwave radiative transfer codes and measurements. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005293] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Stenchikov G, Hamilton K, Robock A, Ramaswamy V, Schwarzkopf MD. Arctic oscillation response to the 1991 Pinatubo eruption in the SKYHI general circulation model with a realistic quasi-biennial oscillation. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jd003699] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Georgiy Stenchikov
- Department of Environmental Sciences; Rutgers University; New Brunswick New Jersey USA
| | - Kevin Hamilton
- International Pacific Research Center; University of Hawaii; Honolulu Hawaii USA
| | - Alan Robock
- Department of Environmental Sciences; Rutgers University; New Brunswick New Jersey USA
| | - V. Ramaswamy
- NOAA Geophysical Fluid Dynamics Laboratory; Princeton University; Princeton New Jersey USA
| | - M. Daniel Schwarzkopf
- NOAA Geophysical Fluid Dynamics Laboratory; Princeton University; Princeton New Jersey USA
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Fomichev VI. Model thermal response to minor radiative energy sources and sinks in the middle atmosphere. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd004892] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nousiainen T. Scattering of light by large Saharan dust particles in a modified ray optics approximation. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2001jd001277] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Garrett TJ. Microphysical and radiative evolution of aerosol plumes over the tropical North Atlantic Ocean. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jd002228] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Erlick C. Sensitivity of the atmospheric lapse rate to solar cloud absorption in a radiative-convective model. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jd002966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Stenchikov G, Robock A, Ramaswamy V, Schwarzkopf MD, Hamilton K, Ramachandran S. Arctic Oscillation response to the 1991 Mount Pinatubo eruption: Effects of volcanic aerosols and ozone depletion. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2002jd002090] [Citation(s) in RCA: 180] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Georgiy Stenchikov
- Department of Environmental Sciences Rutgers University New Brunswick New Jersey USA
| | - Alan Robock
- Department of Environmental Sciences Rutgers University New Brunswick New Jersey USA
| | - V. Ramaswamy
- NOAA Geophysical Fluid Dynamics Laboratory Princeton University Princeton New Jersey USA
| | - M. Daniel Schwarzkopf
- NOAA Geophysical Fluid Dynamics Laboratory Princeton University Princeton New Jersey USA
| | - Kevin Hamilton
- International Pacific Research Center University of Hawaii Honolulu Hawaii USA
| | - S. Ramachandran
- Planetary Atmospheric Sciences Division Physical Research Laboratory Ahmedabad India
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Erlick C, Russell LM, Ramaswamy V. A microphysics-based investigation of the radiative effects of aerosol-cloud interactions for two MAST Experiment case studies. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd900567] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Ramachandran S, Ramaswamy V, Stenchikov GL, Robock A. Radiative impact of the Mount Pinatubo volcanic eruption: Lower stratospheric response. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900355] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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