Detection of large-scale cloud microphysical changes within a major shipping corridor after implementation of the International Maritime Organization 2020 fuel sulfur regulations DOI Creative Commons
Michael Diamond

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(14), P. 8259 - 8269

Published: July 25, 2023

Abstract. New regulations from the International Maritime Organization (IMO) limiting sulfur emissions shipping industry are expected to have large benefits in terms of public health but may come with an undesired side effect: acceleration global warming as climate-cooling effects ship pollution on marine clouds diminished. Previous work has found a substantial decrease detection tracks after IMO 2020 went into effect, changes large-scale cloud properties been more equivocal. Using statistical technique that estimates counterfactual fields what and radiative within isolated corridor southeastern Atlantic would absence shipping, we confidently detect reduction magnitude droplet effective radius decreases find evidence for brightening well. The instantaneous forcing due aerosol–cloud interactions is estimated O(1 W m−2) corridor, lending credence O(0.1 m−2). In addition their geophysical significance, our results also provide independent general compliance regulations.

Language: Английский

Bounding global aerosol radiative forcing of climate change DOI
Nicolas Bellouin, Johannes Quaas, Edward Gryspeerdt

et al.

Published: March 9, 2020

<p>Aerosol radiative forcing plays an important role in the attribution of past climate changes, estimates future allowable carbon emissions, and assessment potential geoengineering solutions. Substantial progress made over 40 years observing, understanding, modelling aerosol processes helped quantify forcing, but uncertainties remain large.</p><p>In spring 2018, under auspices World Climate Research Programme's Grand Science Challenge on Clouds, Circulation Sensitivity, thirty-six experts gathered to take a fresh comprehensive look at present understanding identify prospects for some most pressing open questions. The outcome that meeting is review paper, Bellouin et al. (2019), accepted publication Reviews Geophysics. This provides new range industrial era based multiple, traceable arguable lines evidence, including approaches, theoretical considerations, observations. A substantial achievement focus evidence rather than survey results or expert judgement, make questions much more specific.</p><p>This talk will key messages arguments work show promise improving quantification forcing.</p>

Language: Английский

Citations

349
Scattering and absorbing aerosols in the climate system DOI Open Access
Jing Li, Barbara E. Carlson, Yuk L. Yung

et al.

Nature Reviews Earth & Environment, Journal Year: 2022, Volume and Issue: 3(6), P. 363 - 379

Published: May 24, 2022

Language: Английский

Citations

320
Aerosols enhance cloud lifetime and brightness along the stratus-to-cumulus transition DOI Creative Commons
Matthew W. Christensen, William K. Jones, Philip Stier

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(30), P. 17591 - 17598

Published: July 13, 2020

Significance All cloud droplets on Earth form from tiny airborne particles known as aerosols. Additional aerosols anthropogenic activity have produced more but at smaller sizes. The smaller, numerous in clouds do not collide effectively, therefore resulting less precipitation. Using a combination of time-lapse satellite imagery and air mass trajectory modeling, we show that can enhance fraction extend the lifetime overcast fields primarily under stable atmospheric conditions typically found off west coasts subtropical stratocumulus-dominated regions. Longer-lived stronger cooling influence climate therefore, need to be correctly parameterized models so accurate projections change achieved.

Language: Английский

Citations

248
Aerosol-cloud-climate cooling overestimated by ship-track data DOI
Franziska Glassmeier, Fabian Hoffmann, Jill S. Johnson

et al.

Science, Journal Year: 2021, Volume and Issue: 371(6528), P. 485 - 489

Published: Jan. 28, 2021

Making tracks The magnitude of the effect anthropogenic aerosols on formation clouds is an important unknown about how humans are affecting climate. Studies stratocumulus cloud that formed by ship exhaust have been used to estimate radiative impact this process, but Glassmeier et al. now show approach overestimates cooling aerosol addition up 200%. These findings underscore need quantify responses understand climate system. Science , issue p. 485

Language: Английский

Citations

173
Aerosol‐Forced AMOC Changes in CMIP6 Historical Simulations DOI Creative Commons
Matthew Menary, Jon Robson, Richard P. Allan

et al.

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 47(14)

Published: July 9, 2020

Abstract The Atlantic Meridional Overturning Circulation (AMOC) has been, and will continue to be, a key factor in the modulation of climate change both locally globally. However, there remains considerable uncertainty recent AMOC evolution. Here, we show that multimodel mean strengthened by approximately 10% from 1850–1985 new simulations 6th Coupled Model Intercomparison Project (CMIP6), larger than was seen CMIP5. Across models, strength trend up 1985 is related proxy for aerosol forcing. Therefore, difference result stronger anthropogenic forcing on average CMIP6 CMIP5, which primarily due more models including aerosol‐cloud interactions. observational constraints—including historical sea surface temperature fingerprint shortwave radiative decades—suggest and/or response may be overestimated.

Language: Английский

Citations

158
The hemispheric contrast in cloud microphysical properties constrains aerosol forcing DOI Creative Commons
Isabel L. McCoy, Daniel T. McCoy, Robert Wood

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(32), P. 18998 - 19006

Published: July 27, 2020

Significance Enhancement of aerosol that can nucleate cloud droplets increases the droplet number concentration and albedo clouds. This amount sunlight reflected to space. Uncertainty in how aerosol−cloud interactions over industrial period have increased planetary by this mechanism leads significant uncertainty climate projections. Our work presents a method for observationally constraining change due anthropogenic emissions: hemispheric difference remotely sensed between pristine Southern Ocean (a preindustrial proxy) polluted Northern Hemisphere. Application constraint models reduces range estimated since industrialization suggests current underpredict era.

Language: Английский

Citations

148
The CLoud–Aerosol–Radiation Interaction and Forcing: Year 2017 (CLARIFY-2017) measurement campaign DOI Creative Commons
Jim Haywood, Steven J. Abel, Paul A. Barrett

et al.

Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(2), P. 1049 - 1084

Published: Jan. 27, 2021

Abstract. The representations of clouds, aerosols, and cloud–aerosol–radiation impacts remain some the largest uncertainties in climate change, limiting our ability to accurately reconstruct past predict future climate. south-east Atlantic is a region where high atmospheric aerosol loadings semi-permanent stratocumulus clouds are co-located, providing an optimum for studying full range aerosol–radiation aerosol–cloud interactions their perturbations Earth's radiation budget. While satellite measurements have provided useful insights into over region, these observations do not spatial temporal resolution, nor required level precision allow process-level assessment. Detailed from resolution airborne very sparse, use assessing performance modelling numerical weather prediction models. CLARIFY-2017 was major consortium programme consisting five principal UK universities with project partners Met Office European- USA-based research centres involved complementary ORACLES, LASIC, AEROCLO-sA projects. aims were fourfold: (1) improve representation reduce uncertainty model estimates direct, semi-direct, indirect radiative effect absorbing biomass burning aerosols; (2) knowledge processes determining cloud microphysical properties transition cumulus regimes; (3) challenge, validate, retrievals impacts; (4) aerosols This paper describes measurement strategies central deployment FAAM BAe146 instrumented aircraft campaign, summarizes flight objectives patterns, highlights key results initial analyses.

Language: Английский

Citations

145
Opportunistic experiments to constrain aerosol effective radiative forcing DOI Creative Commons
Matthew W. Christensen, Andrew Gettelman, Jan Čermák

et al.

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(1), P. 641 - 674

Published: Jan. 17, 2022

Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due human activities. The nonlinearity cloud-state changes aerosol perturbations make it challenging attribute causality in observed relationships forcing. Using correlations infer can when meteorological variability also drives both and cloud independently. Natural anthropogenic from well-defined sources provide "opportunistic experiments" (also known as natural experiments) investigate ACI cases where may more confidently inferred. These cover a wide range locations spatiotemporal scales, including point such volcanic eruptions or industrial sources, plumes biomass burning forest fires, tracks individual ships shipping corridors. We review different experimental conditions conduct synthesis available satellite datasets field campaigns place these opportunistic experiments on common footing, facilitating new insights clearer understanding key uncertainties Cloud albedo strongly sensitive background conditions. Strong liquid water path increases largely ruled out by averaging across experiments. Opportunistic have significantly improved process-level ACI, but remains unclear how reliably found scaled global level, thus demonstrating need for deeper investigation order improve assessments climate change.

Language: Английский

Citations

113
Tropical and Boreal Forest – Atmosphere Interactions: A Review DOI Creative Commons
Paulo Artaxo, Hans‐Christen Hansson, Meinrat O. Andreae

et al.

Tellus B, Journal Year: 2022, Volume and Issue: 74(1), P. 24 - 24

Published: March 25, 2022

This review presents how the boreal and tropical forests affect atmosphere, its chemical composition, function, further that affects climate and, in return, ecosystems through feedback processes. Observations from key tower sites standing out due to their long-term comprehensive observations: The Amazon Tall Tower Observatory Central Amazonia, Zotino Siberia, Station Measure Ecosystem-Atmosphere Relations at Hyytiäla Finland. is complemented by short-term observations networks large experiments. discusses atmospheric chemistry observations, aerosol formation processing, physiochemical aerosol, cloud condensation nuclei properties finds surprising similarities important differences two ecosystems. concentrations are similar, particularly concerning main components, both dominated an organic fraction, while ecosystem has generally higher of inorganics, influence long-range transported air pollution. emissions biogenic volatile compounds isoprene monoterpene regions, respectively, being precursors fraction. modeling studies show change deforestation such carbon hydrological cycles Amazonia changing neutrality precipitation downwind. In Africa, so far maintaining sink. It urgent better understand interaction between these major ecosystems, climate, which calls for more observation sites, providing data on water, carbon, other biogeochemical cycles. essential finding a sustainable balance forest preservation reforestation versus potential increase food production biofuels, critical services global stability. Reducing warming vital forests.

Language: Английский

Citations

94
Machine learning reveals climate forcing from aerosols is dominated by increased cloud cover DOI
Ying Chen, Jim Haywood, Yu Wang

et al.

Nature Geoscience, Journal Year: 2022, Volume and Issue: 15(8), P. 609 - 614

Published: Aug. 1, 2022

Language: Английский

Citations

89