The GFDL Earth System Model Version 4.1 (GFDL‐ESM 4.1): Overall Coupled Model Description and Simulation Characteristics

Journal of Advances in Modeling Earth Systems, Journal Year: 2020, Volume and Issue: 12(11)

Published: Aug. 13, 2020

Abstract We describe the baseline coupled model configuration and simulation characteristics of GFDL's Earth System Model Version 4.1 (ESM4.1), which builds on component developments at GFDL over 2013–2018 for carbon‐chemistry‐climate contributing to sixth phase Coupled Intercomparison Project. In contrast with CM4.0 development effort that focuses ocean resolution physical climate, ESM4.1 comprehensiveness system interactions. features doubled horizontal both atmosphere (2° 1°) (1° 0.5°) relative previous‐generation ESM2‐carbon CM3‐chemistry models. brings together key representational advances in dynamics physics along those aerosols their precursor emissions, land ecosystem vegetation canopy competition, multiday fire; ecological biogeochemical interactions, comprehensive land‐atmosphere‐ocean cycling CO 2 , dust iron, interactive ocean‐atmosphere nitrogen are described detail across this volume JAMES presented here terms overall coupling resulting fidelity. provides much improved fidelity chemistry ESM2 CM3, captures most CM4.0's simulations characteristics, notably improves (1) Southern Ocean mode intermediate water ventilation, (2) aerosols, (3) reduced spurious heat uptake. has transient equilibrium climate sensitivity compared CM4.0. Fidelity concerns include moderate degradation sea surface temperature biases, some regions, strong centennial scale modulation by convection.

Language: Английский

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A new model mechanism for atmospheric oxidation of isoprene: global effects on oxidants, nitrogen oxides, organic products, and secondary organic aerosol

Atmospheric chemistry and physics, Journal Year: 2019, Volume and Issue: 19(14), P. 9613 - 9640

Published: July 31, 2019

Abstract. Atmospheric oxidation of isoprene, the most abundantly emitted non-methane hydrocarbon, affects abundances ozone (O3), hydroxyl radical (OH), nitrogen oxide radicals (NOx), carbon monoxide (CO), oxygenated and nitrated organic compounds, secondary aerosol (SOA). We analyze these effects in box models global GEOS-Chem chemical transport model using new reduced Caltech isoprene mechanism (RCIM) condensed from a recently developed explicit mechanism. find many similarities with previous chemistry along number important differences. Proper accounting isomer distribution peroxy following addition OH O2 to influences subsequent products, decreasing particular yield methacrolein increasing capacity intramolecular hydrogen shifts promptly regenerate OH. Hydrogen shift reactions throughout lead increased recycling, resulting less depletion under low-NO conditions than mechanisms. Higher organonitrate yields faster tertiary nitrate hydrolysis more efficient NOx removal by conversion inorganic nitrate. Only 20 % isoprene-derived organonitrates (excluding peroxyacyl nitrates) are chemically recycled NOx. The formaldehyde is 22 per sensitive NO molar glyoxal 2 %, much lower mechanisms because deposition uptake precursors. Global production SOA about one-third each following: epoxydiols (IEPOX), organonitrates, tetrafunctional compounds. 13 carbon, higher commonly assumed likely offset loss. use results our simulations further condense RCIM into mini (Mini-CIM) for expensive implementation atmospheric models, total size (108 species, 345 reactions) comparable currently used

Language: Английский

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Revisiting particle dry deposition and its role in radiative effect estimates

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(42), P. 26076 - 26082

Published: Oct. 5, 2020

Significance Dry deposition is a key sink of atmospheric particles, which impact human and ecosystem health, the radiative balance planet. However, parameterizations used in climate air-quality models are poorly constrained by observations. submicron particles largest uncertainty aerosol indirect forcing. Our particle flux observations indicate that dry velocities an order magnitude lower than suggest. updated, observation-driven should reduce modeled deposition. The scheme increases accumulation mode number concentrations, enhances combined natural anthropogenic effect −0.63 W m −2 , similar to total forcing Intergovernmental Panel on Climate Change report.

Language: Английский

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The fuel of atmospheric chemistry: Toward a complete description of reactive organic carbon

Science Advances, Journal Year: 2020, Volume and Issue: 6(6)

Published: Feb. 6, 2020

Tracking reactive organic carbon in the atmosphere is critical to advancing our understanding of air quality and climate.

Language: Английский

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Rapid dark aging of biomass burning as an overlooked source of oxidized organic aerosol

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(52), P. 33028 - 33033

Published: Dec. 14, 2020

Significance To quantify the full implications of biomass burning emissions on atmosphere, it is essential to accurately represent emission plume after has undergone chemical aging in atmosphere. Atmospheric models typically consider predominant pathway take place presence sunlight (via OH radical); however, this mechanism leads consistent underpredictions oxidized organic aerosol wintertime urban areas. Here, we show, through a combination laboratory experiments, ambient field measurements, and transport modeling, that plumes exposed NO 2 O 3 age rapidly without requiring any sunlight, thus providing an overlooked source previously not accounted for models.

Language: Английский

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The GFDL Global Atmospheric Chemistry‐Climate Model AM4.1: Model Description and Simulation Characteristics

Journal of Advances in Modeling Earth Systems, Journal Year: 2020, Volume and Issue: 12(10)

Published: Aug. 25, 2020

Abstract We describe the baseline model configuration and simulation characteristics of Geophysical Fluid Dynamics Laboratory (GFDL)'s Atmosphere Model version 4.1 (AM4.1), which builds on developments at GFDL over 2013–2018 for coupled carbon‐chemistry‐climate as part sixth phase Coupled Intercomparison Project. In contrast with GFDL's AM4.0 development effort, focused physical aerosol interactions is used atmospheric component CM4.0, AM4.1 focuses comprehensiveness Earth system interactions. Key features this include doubled horizontal resolution atmosphere (~200 to ~100 km) revised dynamics physics from previous‐generation AM3 chemistry‐climate model. improved representation chemical composition, including precursor emissions, key land‐atmosphere interactions, comprehensive land‐atmosphere‐ocean cycling dust iron, interactive ocean‐atmosphere reactive nitrogen. provides vast improvements in fidelity AM3, captures most AM4.0's simulations characteristics, notably improves aerosols Southern Ocean, India, China—even its chemistry representation—and manifestation sudden stratospheric warmings coldest months. Distributions nitrogen sulfur species, carbon monoxide, ozone are all substantially AM3. Fidelity concerns degradation upper equatorial winds some regions.

Language: Английский

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Improved Mechanistic Model of the Atmospheric Redox Chemistry of Mercury

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(21), P. 14445 - 14456

Published: Aug. 17, 2021

We present a new chemical mechanism for Hg0/HgI/HgII atmospheric cycling, including recent laboratory and computational data, implement it in the GEOS-Chem global chemistry model comparison to observations. Our includes oxidation of Hg0 by Br OH, subsequent HgI ozone radicals, respeciation HgII aerosols cloud droplets, speciated photolysis gas aqueous phases. The tropospheric Hg lifetime against deposition is 5.5 months, consistent with observational constraints. reproduces observed surface concentrations wet fluxes. OH make comparable contributions net HgII. Ozone principal oxidant, enabling efficient OH. BrHgIIOH HgII(OH)2, initial products oxidation, respeciate clouds organic inorganic complexes, volatilize photostable forms. Reduction takes place largely through HgII–organic complexes. 71% oceans. Major uncertainties modeling include concentrations, stability reactions HgI, speciation photoreduction clouds.

Language: Английский

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Secondary organic aerosols from anthropogenic volatile organic compounds contribute substantially to air pollution mortality

Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(14), P. 11201 - 11224

Published: July 27, 2021

Abstract. Anthropogenic secondary organic aerosol (ASOA), formed from anthropogenic emissions of compounds, constitutes a substantial fraction the mass submicron in populated areas around world and contributes to poor air quality premature mortality. However, precursor sources ASOA are poorly understood, there large uncertainties health benefits that might accrue reducing emissions. We show production 11 urban on three continents is strongly correlated with reactivity specific volatile compounds. The differences across different cities can be explained by aromatics intermediate- semi-volatile indicating importance controlling these precursors. With an improved model representation driven observations, we attribute 340 000 PM2.5-related deaths per year ASOA, which over order magnitude higher than prior studies. A sensitivity case more recently proposed for attributing mortality PM2.5 (the Global Exposure Mortality Model) results up 900 deaths. limitation this study extrapolation detailed studies regions where emission inventories available other larger. In addition further development institutional management infrastructure, comprehensive campaigns countries South Central America, Africa, Asia, Middle East needed progress area.

Language: Английский

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Nitrogen oxides in the free troposphere: implications for tropospheric oxidants and the interpretation of satellite NO₂ measurements

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(2), P. 1227 - 1257

Published: Jan. 24, 2023

Abstract. Satellite-based retrievals of tropospheric NO2 columns are widely used to infer NOx (≡ NO + NO2) emissions. These rely on model information for the vertical distribution NO2. The free background above 2 km is particularly important because sensitivity increases with altitude. Free also has a strong effect OH and ozone concentrations. Here we use observations from three aircraft campaigns (SEAC4RS, DC3, ATom) four atmospheric chemistry models (GEOS-Chem, GMI, TM5, CAMS) evaluate capabilities simulating in troposphere attribute it sources. measurements during Studies Emissions Atmospheric Composition, Clouds, Climate Coupling by Regional Surveys (SEAC4RS) Deep Convective Clouds Chemistry (DC3) over southeastern U.S. summer show increasing concentrations upper 10 km, which not replicated GEOS-Chem, although consistent measurements. Using concurrent NO, NO2, DC3 flight thunderstorm outflow, that biased high, plausibly due interference thermally labile reservoirs such as peroxynitric acid (HNO4) methyl peroxy nitrate (MPN). We find calculated NO–NO2 photochemical steady state (PSS) more reliable profiles models. GEOS-Chem reproduces shape PSS-inferred throughout SEAC4RS but overestimates about factor 2. underestimates MPN alkyl concentrations, suggesting missing organic chemistry. On other hand, standard Tomography Mission (ATom) Pacific Atlantic oceans, indicating source oceans. can account this including photolysis particulate sea salt aerosols at rates inferred laboratory studies field nitrous (HONO) Atlantic. median column density ATom campaign 1.7 ± 0.44 × 1014 molec. cm−2, simulated range 1.4–2.4 implying uncertainty using modeled clean areas stratosphere–troposphere separation 1 cm−2. lightning main primary tropics southern midlatitudes, emissions dominate northern midlatitudes winter Particulate up 5 ppbv (parts per billion volume) extratropics model, would largely correct low bias relative ozonesonde observations. Global increase 19 %. contribution observed satellites contiguous 25 11 % 65 9 summer, according profiles. This needs be accounted when deriving satellite

Language: Английский

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Evaluating Organic Aerosol Sources and Evolution with a Combined Molecular Composition and Volatility Framework Using the Filter Inlet for Gases and Aerosols (FIGAERO)

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(8), P. 1415 - 1426

Published: July 10, 2020

ConspectusThe complex array of sources and transformations organic carbonaceous material that comprises an important fraction atmospheric fine particle mass, known as aerosol, has presented a long running challenge for accurate predictions its abundance, distribution, sensitivity to anthropogenic activities. Uncertainties about changes in aerosol abundance over time translate uncertainties their impact on Earth's climate response air quality policy. One limitation our understanding been lack comprehensive measurements molecular composition volatility, which can elucidate processes affecting abundance. Herein we describe advances the development application Filter Inlet Gases Aerosols (FIGAERO) coupled field-deployable High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometers (HRToF-CIMS). The FIGAERO HRToFCIMS combination broadly probes gas particulate OA by using programmed thermal desorption particles collected Teflon filter with subsequent detection speciation desorbed vapors inherently quantitative selected-ion chemical ionization. provides means obtain insights into volatility components thus physicochemical nature will govern evolution atmosphere.In this Account, discuss design operation FIGAERO, when HRToF-CIMS, characterization molecular-level effective laboratory field. We provide example gleaned from deployment, improve evolution. Specifically, connect profiles equilibrium saturation vapor concentration enthalpy vaporization detected components. also show how HRToF-CIMS environmental simulation chamber experiments field new constraints mechanisms governing secondary formation dynamic associated challenges decomposition during calibration both axis signal. illustrate additional through isothermal evaporation well ultrafine composition. conclude description future opportunities needs ability further science.

Language: Английский

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