Articles | Volume 23, issue 2
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Hemispheric-wide climate response to regional COVID-19-related aerosol emission reductions: the prominent role of atmospheric circulation adjustments
Nora L. S. Fahrenbach
School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
Massimo A. Bollasina
School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
No articles found.
Laura J. Wilcox, Robert J. Allen, Bjørn H. Samset, Massimo A. Bollasina, Paul T. Griffiths, James Keeble, Marianne T. Lund, Risto Makkonen, Joonas Merikanto, Declan O'Donnell, David J. Paynter, Geeta G. Persad, Steven T. Rumbold, Toshihiko Takemura, Kostas Tsigaridis, Sabine Undorf, and Daniel M. Westervelt
Geosci. Model Dev., 16, 4451–4479,Short summary
Changes in anthropogenic aerosol emissions have strongly contributed to global and regional climate change. However, the size of these regional impacts and the way they arise are still uncertain. With large changes in aerosol emissions a possibility over the next few decades, it is important to better quantify the potential role of aerosol in future regional climate change. The Regional Aerosol Model Intercomparison Project will deliver experiments designed to facilitate this.
Joseph Albert Smith, Cathryn Birch, John Marsham, Simon Peatman, Massimo Bollasina, and George Pankiewicz
Nowcasting uses observations to make predictions of the atmosphere on short time scales and is particularly applicable to the Maritime Continent where storms rapidly develop and cause natural disasters. This paper evaluates probabilistic and deterministic satellite nowcasting algorithms over the Maritime Continent. We show that the probabilistic approach is most skilful at small scales (~60 km) whereas the deterministic approach is most skilful at larger scales (~200 km).
Andrew P. Schurer, Gabriele C. Hegerl, Hugues Goosse, Massimo A. Bollasina, Matthew H. England, Michael J. Mineter, Doug M. Smith, and Simon F. B. Tett
Clim. Past, 19, 943–957,Short summary
We adopt an existing data assimilation technique to constrain a model simulation to follow three important modes of variability, the North Atlantic Oscillation, El Niño–Southern Oscillation and the Southern Annular Mode. How it compares to the observed climate is evaluated, with improvements over simulations without data assimilation found over many regions, particularly the tropics, the North Atlantic and Europe, and discrepancies with global cooling following volcanic eruptions are reconciled.
Liang Guo, Laura J. Wilcox, Massimo Bollasina, Steven T. Turnock, Marianne T. Lund, and Lixia Zhang
Atmos. Chem. Phys., 21, 15299–15308,Short summary
Severe haze remains serious over Beijing despite emissions decreasing since 2008. Future haze changes in four scenarios are studied. The pattern conducive to haze weather increases with the atmospheric warming caused by the accumulation of greenhouse gases. However, the actual haze intensity, measured by either PM2.5 or optical depth, decreases with aerosol emissions. We show that only using the weather pattern index to predict the future change of Beijing haze is insufficient.
Francesco S. R. Pausata, Gabriele Messori, Jayoung Yun, Chetankumar A. Jalihal, Massimo A. Bollasina, and Thomas M. Marchitto
Clim. Past, 17, 1243–1271,Short summary
Far-afield changes in vegetation such as those that occurred over the Sahara during the middle Holocene and the consequent changes in dust emissions can affect the intensity of the South Asian Monsoon (SAM) rainfall and the lengthening of the monsoon season. This remote influence is mediated by anomalies in Indian Ocean sea surface temperatures and may have shaped the evolution of the SAM during the termination of the African Humid Period.
Lixia Zhang, Laura J. Wilcox, Nick J. Dunstone, David J. Paynter, Shuai Hu, Massimo Bollasina, Donghuan Li, Jonathan K. P. Shonk, and Liwei Zou
Atmos. Chem. Phys., 21, 7499–7514,Short summary
The projected frequency of circulation patterns associated with haze events and global warming increases significantly due to weakening of the East Asian winter monsoon. Rapid reduction in anthropogenic aerosol further increases the frequency of circulation patterns, but haze events are less dangerous. We revealed competing effects of aerosol emission reductions on future haze events through their direct contribution to haze intensity and their influence on the atmospheric circulation patterns.
Laura J. Wilcox, Zhen Liu, Bjørn H. Samset, Ed Hawkins, Marianne T. Lund, Kalle Nordling, Sabine Undorf, Massimo Bollasina, Annica M. L. Ekman, Srinath Krishnan, Joonas Merikanto, and Andrew G. Turner
Atmos. Chem. Phys., 20, 11955–11977,Short summary
Projected changes in man-made aerosol range from large reductions to moderate increases in emissions until 2050. Rapid reductions between the present and the 2050s lead to enhanced increases in global and Asian summer monsoon precipitation relative to scenarios with continued increases in aerosol. Relative magnitude and spatial distribution of aerosol changes are particularly important for South Asian summer monsoon precipitation changes, affecting the sign of the trend in the coming decades.
Zhen Liu, Yi Ming, Chun Zhao, Ngar Cheung Lau, Jianping Guo, Massimo Bollasina, and Steve Hung Lam Yim
Atmos. Chem. Phys., 20, 223–241,Short summary
OH and HO2 radicals are important trace constituents of the atmosphere that are closely coupled via several types of reaction. This paper describes a new laboratory method to simultaneously determine OH kinetics and HO2 yields from chemical processes. The instrument also provides some time resolution on HO2 detection allowing one to separate HO2 produced from the target reaction from HO2 arising from secondary chemistry. Examples of applications are presented.
Alcide Zhao, Massimo A. Bollasina, Monica Crippa, and David S. Stevenson
Atmos. Chem. Phys., 19, 14517–14533,Short summary
Emissions of aerosols over the recent past have been regulated largely by two policy-relevant drivers: energy-use growth and technology advances. These generate large and competing impacts on global radiation balance and climate, particularly over Asia, Europe, and the Arctic. This may help better assess and interpret future climate projections, and hence inform future climate change impact reduction strategies. Yet, it is pressing to better constrain various uncertainties related to aerosols.
Laura J. Wilcox, Nick Dunstone, Anna Lewinschal, Massimo Bollasina, Annica M. L. Ekman, and Eleanor J. Highwood
Atmos. Chem. Phys., 19, 9081–9095,Short summary
Asian anthropogenic aerosol emissions have increased rapidly since 1980. In winter, this has resulted in warming over China and cooling over India. Using models of different levels of complexity, we show that Asian-aerosol-induced heating anomalies in the western and northern North Pacific establish a circulation pattern that causes cooling in North America and Europe. This connection makes these regions potentially sensitive to any reductions of Asian aerosol emissions in the near future.
Related subject area
Subject: Aerosols | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Impacts of reducing scattering and absorbing aerosols on the temporal extent and intensity of South Asian summer monsoon and East Asian summer monsoonSuperimposed effects of typical local circulations driven by mountainous topography and aerosol–radiation interaction on heavy haze in the Beijing–Tianjin–Hebei central and southern plains in winterMulti-model ensemble projection of the global dust cycle by the end of 21st century using the Coupled Model Intercomparison Project version 6 dataA thermodynamic framework for bulk–surface partitioning in finite-volume mixed organic–inorganic aerosol particles and cloud dropletsChange from aerosol-driven to cloud-feedback-driven trend in short-wave radiative flux over the North AtlanticA new process-based and scale-aware desert dust emission scheme for global climate models – Part I: Description and evaluation against inverse modeling emissionsTransported aerosols regulate the pre-monsoon rainfall over north-east India: a WRF-Chem modelling studyCollision-sticking rates of acid–base clusters in the gas phase determined from atomistic simulation and a novel analytical interacting hard-sphere modelParameterization of size of organic and secondary inorganic aerosol for efficient representation of global aerosol optical propertiesModel-based insights into aerosol perturbation on pristine continental convective precipitationThe impact of using assimilated Aeolus wind data on regional WRF-Chem dust simulationsOn the differences in the vertical distribution of modeled aerosol optical depth over the southeastern AtlanticA global evaluation of daily to seasonal aerosol and water vapor relationships using a combination of AERONET and NAAPS reanalysis dataAtlantic Multi-decadal Oscillation Modulates the Relationship Between El Niño-Southern Oscillation and Fire Weather in AustraliaLocal and remote climate impacts of future African aerosol emissionsThe dependence of aerosols' global and local precipitation impacts on the emitting regionAssessing the climate and air quality effects of future aerosol mitigation in India using a global climate model combined with statistical downscalingAggravated air pollution and health burden due to traffic congestion in urban ChinaLate summer transition from a free-tropospheric to boundary layer source of Aitken mode aerosol in the high ArcticSelf-lofting of wildfire smoke in the troposphere and stratosphere: simulations and space lidar observationsAerosol emissions estimation with POLDERThe underappreciated role of transboundary pollution in future air quality and health improvements in ChinaIdentifying climate model structural inconsistencies allows for tight constraint of aerosol radiative forcingRole of K-feldspar and quartz in global ice nucleation by mineral dust in mixed-phase cloudsProjected increases in wildfires may challenge regulatory curtailment of PM2.5 over the eastern US by 2050Meteorological export and deposition fluxes of black carbon on glaciers of the central Chilean AndesFuture changes in atmospheric rivers over East Asia under stratospheric aerosol interventionModeling the influence of chain length on secondary organic aerosol (SOA) formation via multiphase reactions of alkanesHow aerosol size matters in aerosol optical depth (AOD) assimilation and the optimization using the Ångström exponentMicrophysical, macrophysical, and radiative responses of subtropical marine clouds to aerosol injectionsImpacts of an aerosol layer on a midlatitude continental system of cumulus clouds: how do these impacts depend on the vertical location of the aerosol layer?Impact of phase state and non-ideal mixing on equilibration timescales of secondary organic aerosol partitioningEffect of radiation interaction and aerosol processes on ventilation and aerosol concentrations in a real urban neighbourhood in HelsinkiA global climatology of ice-nucleating particles under cirrus conditions derived from model simulations with MADE3 in EMACEnviro-HIRLAM model estimates of elevated black carbon pollution over Ukraine resulted from forest firesWhere does the dust deposited over the Sierra Nevada snow come from?Instant and delayed effects of March biomass burning aerosols over the Indochina PeninsulaAerosol–cloud interaction in the atmospheric chemistry model GRAPES_Meso5.1/CUACE and its impacts on mesoscale numerical weather prediction under haze pollution conditions in Jing–Jin–Ji in ChinaSurvival probabilities of atmospheric particles: comparison based on theory, cluster population simulations, and observations in BeijingAir pollution reductions caused by the COVID-19 lockdown open up a way to preserve the Himalayan snow coverThe simulation of mineral dust in the United Kingdom Earth System Model UKESM1Dust pollution in China affected by different spatial and temporal types of El NiñoThe export of African mineral dust across the Atlantic and its impact over the Amazon BasinAn improved representation of aerosol mixing state for air quality–weather interactionsCirculation-regulated impacts of aerosol pollution on urban heat island in BeijingSize-resolved dust direct radiative effect efficiency derived from satellite observationsModeling coarse and giant desert dust particlesFire–climate interactions through the aerosol radiative effect in a global chemistry–climate–vegetation modelContributions of meteorology and anthropogenic emissions to the trends in winter PM2.5 in eastern China 2013–2018Impacts of condensable particulate matter on atmospheric organic aerosols and fine particulate matter (PM2.5) in China
Chenwei Fang, Jim M. Haywood, Ju Liang, Ben T. Johnson, Ying Chen, and Bin Zhu
Atmos. Chem. Phys., 23, 8341–8368,Short summary
The responses of Asian summer monsoon duration and intensity to air pollution mitigation are identified given the net-zero future. We show that reducing scattering aerosols makes the rainy season longer and stronger across South Asia and East Asia but that absorbing aerosol reduction has the opposite effect. Our results hint at distinct monsoon responses to emission controls that target different aerosols.
Yue Peng, Hong Wang, Xiaoye Zhang, Zhaodong Liu, Wenjie Zhang, Siting Li, Chen Han, and Huizheng Che
Atmos. Chem. Phys., 23, 8325–8339,Short summary
This study demonstrates a strong link between local circulation, aerosol–radiation interaction (ARI), and haze pollution. Under the weak weather-scale systems, the typical local circulation driven by mountainous topography is the main cause of pollutant distribution in the Beijing–Tianjin–Hebei region, and the ARI mechanism amplifies this influence of local circulation on pollutants, making haze pollution aggravated by the superposition of both.
Yuan Zhao, Xu Yue, Yang Cao, Jun Zhu, Chenguang Tian, Hao Zhou, Yuwen Chen, Yihan Hu, Weijie Fu, and Xu Zhao
Atmos. Chem. Phys., 23, 7823–7838,Short summary
We project the future changes of dust emissions and loading using an ensemble of model outputs from the Coupled Model Intercomparison Project version 6 under four scenarios. We find increased dust emissions and loading in North Africa, due to increased drought and strengthened surface wind, and decreased dust loading over Asia, following enhanced precipitation. Such a spatial pattern remains similar, though the regional intensity varies among different scenarios.
Ryan Schmedding and Andreas Zuend
Atmos. Chem. Phys., 23, 7741–7765,Short summary
Aerosol particles below 100 nm in diameter have high surface-area-to-volume ratios. The enrichment of compounds in the surface of an aerosol particle may lead to depletion of that species in the interior bulk of the particle. We present a framework for modeling the equilibrium bulk–surface partitioning of mixed organic–inorganic particles, including cases of co-condensation of semivolatile organic compounds and species with extremely limited solubility in the bulk or surface of a particle.
Daniel P. Grosvenor and Kenneth S. Carslaw
Atmos. Chem. Phys., 23, 6743–6773,Short summary
We determine what causes long-term trends in short-wave (SW) radiative fluxes in two climate models. A positive trend occurs between 1850 and 1970 (increasing SW reflection) and a negative trend between 1970 and 2014; the pre-1970 positive trend is mainly driven by an increase in cloud droplet number concentrations due to increases in aerosol, and the 1970–2014 trend is driven by a decrease in cloud fraction, which we attribute to changes in clouds caused by greenhouse gas-induced warming.
Danny M. Leung, Jasper F. Kok, Longlei Li, Gregory S. Okin, Catherine Prigent, Martina Klose, Carlos Pérez García-Pando, Laurent Menut, Natalie M. Mahowald, David M. Lawrence, and Marcelo Chamecki
Atmos. Chem. Phys., 23, 6487–6523,Short summary
Desert dust modeling is important for understanding climate change, as dust regulates the atmosphere's greenhouse effect and radiation. This study formulates and proposes a more physical and realistic desert dust emission scheme for global and regional climate models. By considering more aeolian processes in our emission scheme, our simulations match better against dust observations than existing schemes. We believe this work is vital in improving dust representation in climate models.
Neeldip Barman and Sharad Gokhale
Atmos. Chem. Phys., 23, 6197–6215,Short summary
The study shows that during the pre-monsoon season transported aerosols, especially from the Indo-Gangetic Plain (IGP), have a greater impact with respect to air pollution, radiative forcing and rainfall over north-east (NE) India than emissions from within NE India itself. Hence, controlling emissions in the IGP will be significantly more fruitful in reducing pollution as well as climatic impacts over this region.
Huan Yang, Ivo Neefjes, Valtteri Tikkanen, Jakub Kubečka, Theo Kurtén, Hanna Vehkamäki, and Bernhard Reischl
Atmos. Chem. Phys., 23, 5993–6009,Short summary
We present a new analytical model for collision rates between molecules and clusters of arbitrary sizes, accounting for long-range interactions. The model is verified against atomistic simulations of typical acid–base clusters participating in atmospheric new particle formation (NPF). Compared to non-interacting models, accounting for long-range interactions leads to 2–3 times higher collision rates for small clusters, indicating the necessity of including such interactions in NPF modeling.
Haihui Zhu, Randall V. Martin, Betty Croft, Shixian Zhai, Chi Li, Liam Bindle, Jeffrey R. Pierce, Rachel Y.-W. Chang, Bruce E. Anderson, Luke D. Ziemba, Johnathan W. Hair, Richard A. Ferrare, Chris A. Hostetler, Inderjeet Singh, Deepangsu Chatterjee, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jack E. Dibb, Joshua S. Schwarz, and Andrew Weinheimer
Atmos. Chem. Phys., 23, 5023–5042,Short summary
Particle size of atmospheric aerosol is important for estimating its climate and health effects, but simulating atmospheric aerosol size is computationally demanding. This study derives a simple parameterization of the size of organic and secondary inorganic ambient aerosol that can be applied to atmospheric models. Applying this parameterization allows a better representation of the global spatial pattern of aerosol size, as verified by ground and airborne measurements.
Mengjiao Jiang, Yaoting Li, Weiji Hu, Yinshan Yang, Guy Brasseur, and Xi Zhao
Atmos. Chem. Phys., 23, 4545–4557,Short summary
Relatively clean background aerosol over the Tibetan Plateau makes the study of aerosol–cloud–precipitation interactions distinctive. A convection on 24 July 2014 in Naqu was selected using the Weather Research Forecasting (WRF) model, including the Thompson aerosol-aware microphysical scheme. Our study uses a compromise approach to the limited observations. We show that the transformation of cloud water to graupel and the development of convective clouds are favored in a polluted situation.
Pantelis Kiriakidis, Antonis Gkikas, Georgios Papangelis, Theodoros Christoudias, Jonilda Kushta, Emmanouil Proestakis, Anna Kampouri, Eleni Marinou, Eleni Drakaki, Angela Benedetti, Michael Rennie, Christian Retscher, Anne Grete Straume, Alexandru Dandocsi, Jean Sciare, and Vasilis Amiridis
Atmos. Chem. Phys., 23, 4391–4417,Short summary
With the launch of the Aeolus satellite, higher-accuracy wind products became available. This research was carried out to validate the assimilated wind products by testing their effect on the WRF-Chem model predictive ability of dust processes. This was carried out for the eastern Mediterranean and Middle East region for two 2-month periods in autumn and spring 2020. The use of the assimilated products improved the dust forecasts of the autumn season (both quantitatively and qualitatively).
Ian Chang, Lan Gao, Connor J. Flynn, Yohei Shinozuka, Sarah J. Doherty, Michael S. Diamond, Karla M. Longo, Gonzalo A. Ferrada, Gregory R. Carmichael, Patricia Castellanos, Arlindo M. da Silva, Pablo E. Saide, Calvin Howes, Zhixin Xue, Marc Mallet, Ravi Govindaraju, Qiaoqiao Wang, Yafang Cheng, Yan Feng, Sharon P. Burton, Richard A. Ferrare, Samuel E. LeBlanc, Meloë S. Kacenelenbogen, Kristina Pistone, Michal Segal-Rozenhaimer, Kerry G. Meyer, Ju-Mee Ryoo, Leonhard Pfister, Adeyemi A. Adebiyi, Robert Wood, Paquita Zuidema, Sundar A. Christopher, and Jens Redemann
Atmos. Chem. Phys., 23, 4283–4309,Short summary
Abundant aerosols are present above low-level liquid clouds over the southeastern Atlantic during late austral spring. The model simulation differences in the proportion of aerosol residing in the planetary boundary layer and in the free troposphere can greatly affect the regional aerosol radiative effects. This study examines the aerosol loading and fractional aerosol loading in the free troposphere among various models and evaluates them against measurements from the NASA ORACLES campaign.
Juli I. Rubin, Jeffrey S. Reid, Peng Xian, Christopher M. Selman, and Thomas F. Eck
Atmos. Chem. Phys., 23, 4059–4090,Short summary
This work aims to quantify the covariability between aerosol optical depth/extinction with water vapor (PW) globally, using NASA AERONET observations and NAAPS model data. Findings are important for data assimilation and radiative transfer. The study shows statistically significant and positive AOD–PW relationships are found across the globe, varying in strength with location and season and tied to large-scale aerosol events. Hygroscopic growth was also found to be an important factor.
Guanyu Liu, Jing Li, and Tong Ying
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Fire weather in Australia is positively correlated with El Niño-Southern Oscillation (ENSO). However, their correlation is strengthened in the last two decades. Here, we show the correlation between ENSO and Australia fire weather index (FWI) increases from 0.17 to 0.70 when AMO shifts from its negative to positive phase. This is explained by the teleconnection effect. Warmer Atlantic generates Rossby wave trains and results in high pressures and a weather condition conducive to wildfires.
Christopher D. Wells, Matthew Kasoar, Nicolas Bellouin, and Apostolos Voulgarakis
Atmos. Chem. Phys., 23, 3575–3593,Short summary
The climate is altered by greenhouse gases and air pollutant particles, and such emissions are likely to change drastically in the future over Africa. Air pollutants do not travel far, so their climate effect depends on where they are emitted. This study uses a climate model to find the climate impacts of future African pollutant emissions being either high or low. The particles absorb and scatter sunlight, causing the ground nearby to be cooler, but elsewhere the increased heat causes warming.
Geeta G. Persad
Atmos. Chem. Phys., 23, 3435–3452,Short summary
Human-induced aerosol pollution has major impacts on both local and global precipitation. This study demonstrates using a global climate model that both the strength and localization of aerosols' precipitation impacts are highly dependent on which region the aerosols are emitted from. The findings highlight that the geographic distribution of human-induced aerosol emissions must be accounted for when quantifying their influence on global precipitation.
Tuuli Miinalainen, Harri Kokkola, Antti Lipponen, Antti-Pekka Hyvärinen, Vijay Kumar Soni, Kari E. J. Lehtinen, and Thomas Kühn
Atmos. Chem. Phys., 23, 3471–3491,Short summary
We simulated the effects of aerosol emission mitigation on both global and regional radiative forcing and city-level air quality with a global-scale climate model. We used a machine learning downscaling approach to bias-correct the PM2.5 values obtained from the global model for the Indian megacity New Delhi. Our results indicate that aerosol mitigation could result in both improved air quality and less radiative heating for India.
Peng Wang, Ruhan Zhang, Shida Sun, Meng Gao, Bo Zheng, Dan Zhang, Yanli Zhang, Gregory R. Carmichael, and Hongliang Zhang
Atmos. Chem. Phys., 23, 2983–2996,Short summary
In China, the number of vehicles has jumped significantly in the last decade. This caused severe traffic congestion and aggravated air pollution. In this study, we developed a new temporal allocation approach to quantify the impacts of traffic congestion. We found that traffic congestion worsens air quality and the health burden across China, especially in the urban clusters. More effective and comprehensive vehicle emission control policies should be implemented to improve air quality in China.
Ruth Price, Andrea Baccarini, Julia Schmale, Paul Zieger, Ian M. Brooks, Paul Field, and Ken S. Carslaw
Atmos. Chem. Phys., 23, 2927–2961,Short summary
Arctic clouds can control how much energy is absorbed by the surface or reflected back to space. Using a computer model of the atmosphere we investigated the formation of atmospheric particles that allow cloud droplets to form. We found that particles formed aloft are transported to the lowest part of the Arctic atmosphere and that this is a key source of particles. Our results have implications for the way Arctic clouds will behave in the future as climate change continues to impact the region.
Kevin Ohneiser, Albert Ansmann, Jonas Witthuhn, Hartwig Deneke, Alexandra Chudnovsky, Gregor Walter, and Fabian Senf
Atmos. Chem. Phys., 23, 2901–2925,Short summary
This study shows that smoke layers can reach the tropopause via the self-lofting effect within 3–7 d in the absence of pyrocumulonimbus convection if the aerosol optical thickness is larger than approximately 2 for a longer time period. When reaching the stratosphere, wildfire smoke can sensitively influence the stratospheric composition on a hemispheric scale and thus can affect the Earth’s climate and the ozone layer.
Athanasios Tsikerdekis, Otto P. Hasekamp, Nick A. J. Schutgens, and Qirui Zhong
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Aerosol are tiny particles of different substance (species) that can be emitted into the atmosphere by natural processes or by anthropogenic activities. However, the actual aerosol emission amount per species is highly uncertain. Thus in this work we are correcting the aerosol emissions used to drive a global aerosol/climate model using satellite observations through a process called data assimilation. These more accurate aerosol emissions can lead to a more accurate weather/climate prediction.
Jun-Wei Xu, Jintai Lin, Dan Tong, and Lulu Chen
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
This study highlights the necessity of a low-carbon pathway in foreign countries for China to achieve air quality goals and to protect public health. We find that adopting the low-carbon instead of the fossil fuel-intensive pathway in foreign countries would avoid 63,000–270,000 transboundary PM2.5-associated mortality in China in 2060. Our study provides direct evidence on the necessity of inter-regional cooperation for air quality improvement.
Leighton A. Regayre, Lucia Deaconu, Daniel P. Grosvenor, David M. H. Sexton, Christopher Symonds, Tom Langton, Duncan Watson-Paris, Jane P. Mulcahy, Kirsty J. Pringle, Mark Richardson, Jill S. Johnson, John W. Rostron, Hamish Gordon, Grenville Lister, Philip Stier, and Ken S. Carslaw
Aerosol forcing of Earth’s energy balance has persisted as a major cause of uncertainty in climate simulations over generations of climate model development. We show that structural deficiencies in a climate model are exposed by comprehensively exploring parametric uncertainty, and that these deficiencies limit how much the model uncertainty can be reduced through observational constraint. This provides a future pathway towards building models with greater physical realism and lower uncertainty.
Marios Chatziparaschos, Nikos Daskalakis, Stelios Myriokefalitakis, Nikos Kalivitis, Athanasios Nenes, María Gonçalves Ageitos, Montserrat Costa-Surós, Carlos Pérez García-Pando, Medea Zanoli, Mihalis Vrekoussis, and Maria Kanakidou
Atmos. Chem. Phys., 23, 1785–1801,Short summary
Ice formation is enabled by ice-nucleating particles (INP) at higher temperatures than homogeneous formation and can profoundly affect the properties of clouds. Our global model results show that K-feldspar is the most important contributor to INP concentrations globally, affecting mid-level mixed-phase clouds. However, quartz can significantly contribute and dominates the lowest and the highest altitudes of dust-derived INP, affecting mainly low-level and high-level mixed-phase clouds.
Chandan Sarangi, Yun Qian, L. Ruby Leung, Yang Zhang, Yufei Zou, and Yuhang Wang
Atmos. Chem. Phys., 23, 1769–1783,Short summary
We show that for air quality, the densely populated eastern US may see even larger impacts of wildfires due to long-distance smoke transport and associated positive climatic impacts, partially compensating the improvements from regulations on anthropogenic emissions. This study highlights the tension between natural and anthropogenic contributions and the non-local nature of air pollution that complicate regulatory strategies for improving future regional air quality for human health.
Rémy Lapere, Nicolás Huneeus, Sylvain Mailler, Laurent Menut, and Florian Couvidat
Atmos. Chem. Phys., 23, 1749–1768,Short summary
Glaciers in the Andes of central Chile are shrinking rapidly in response to global warming. This melting is accelerated by the deposition of opaque particles onto snow and ice. In this work, model simulations quantify typical deposition rates of soot on glaciers in summer and winter months and show that the contribution of emissions from Santiago is not as high as anticipated. Additionally, the combination of regional- and local-scale meteorology explains the seasonality in deposition.
Ju Liang and Jim Haywood
Atmos. Chem. Phys., 23, 1687–1703,Short summary
The recent record-breaking flood events in China during the summer of 2021 highlight the importance of mitigating the risks from future changes in high-impact weather systems under global warming. Based on a state-of-the-art Earth system model, we demonstrate a pilot study on the responses of atmospheric rivers and extreme precipitation over East Asia to anthropogenically induced climate warming and an unconventional mitigation strategy – stratospheric aerosol injection.
Azad Madhu, Myoseon Jang, and David Deacon
Atmos. Chem. Phys., 23, 1661–1675,Short summary
SOA formation is simulated using the UNIPAR model for series of linear alkanes. The inclusion of autoxidation reactions within the explicit gas mechanisms of C9–C12 was found to significantly improve predictions. Available product distributions were extrapolated with an incremental volatility coefficient (IVC) to predict SOA formation of alkanes without explicit mechanisms. These product distributions were used to simulate SOA formation from C13 and C15 and had good agreement with chamber data.
Jianbing Jin, Bas Henzing, and Arjo Segers
Atmos. Chem. Phys., 23, 1641–1660,Short summary
Aerosol models and satellite retrieval algorithms rely on different aerosol size assumptions. In practice, differences between simulations and observations do not always reflect the difference in aerosol amount. To avoid inconsistencies, we designed a hybrid assimilation approach. Different from a standard aerosol optical depth (AOD) assimilation that directly assimilates AODs, the hybrid one estimates aerosol size parameters by assimilating Ängström observations before assimilating the AODs.
Je-Yun Chun, Robert Wood, Peter Blossey, and Sarah J. Doherty
Atmos. Chem. Phys., 23, 1345–1368,Short summary
We investigate the impact of injected aerosol on subtropical low marine clouds under a variety of meteorological conditions using high-resolution model simulations. This study illustrates processes perturbed by aerosol injections and their impact on cloud properties (e.g., cloud number concentration, thickness, and cover). We show that those responses are highly sensitive to background meteorological conditions, such as precipitation, and background cloud properties.
Seoung Soo Lee, Junshik Um, Won Jun Choi, Kyung-Ja Ha, Chang Hoon Jung, Jianping Guo, and Youtong Zheng
Atmos. Chem. Phys., 23, 273–286,Short summary
This paper elaborates on process-level mechanisms regarding how the interception of radiation by aerosols interacts with the surface heat fluxes and atmospheric instability in warm cumulus clouds. This paper elucidates how these mechanisms vary with the location or altitude of an aerosol layer. This elucidation indicates that the location of aerosol layers should be taken into account for parameterizations of aerosol–cloud interactions.
Meredith Schervish and Manabu Shiraiwa
Atmos. Chem. Phys., 23, 221–233,Short summary
Secondary organic aerosols (SOAs) can exhibit complex non-ideal behavior and adopt an amorphous semisolid state. We simulate condensation of semi-volatile compounds into a phase-separated particle to investigate the effect of non-ideality and particle phase state on the equilibration timescale of SOA partitioning. Our results provide useful insights into the interpretation of experimental observations and the description and treatment of SOA in aerosol models.
Jani Strömberg, Xiaoyu Li, Mona Kurppa, Heino Kuuluvainen, Liisa Pirjola, and Leena Järvi
In this study we concluded that with low wind speeds, solar radiation has a larger decreasing effect (53 %) on pollutant concentrations than aerosol processes (18 %). Additionally, our results showed that with solar radiation included, pollutant concentrations were closer to observations (-13 %) than with only aerosol processes (+97 %). This has implications when planning simulations under calm conditions such as our case and deciding whether or not simulations need to include these processes.
Christof G. Beer, Johannes Hendricks, and Mattia Righi
Atmos. Chem. Phys., 22, 15887–15907,Short summary
Ice-nucleating particles (INPs) have important influences on cirrus clouds and the climate system; however, their global atmospheric distribution in the cirrus regime is still very uncertain. We present a global climatology of INPs under cirrus conditions derived from model simulations, considering the mineral dust, soot, crystalline ammonium sulfate, and glassy organics INP types. The comparison of respective INP concentrations indicates the large importance of ammonium sulfate particles.
Mykhailo Savenets, Larysa Pysarenko, Svitlana Krakovska, Alexander Mahura, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 15777–15791,Short summary
The paper explores the spatio-temporal variability of black carbon during a wildfire in August 2010, with a focus on Ukraine. As a research tool, the seamless Enviro-HIRLAM modelling system is used for investigating the atmospheric transport of aerosol particles emitted by wildfires from remote and local sources. The results of this study improve our understanding of the physical and chemical processes and the interactions of aerosols in the atmosphere.
Huilin Huang, Yun Qian, Ye Liu, Cenlin He, Jianyu Zheng, Zhibo Zhang, and Antonis Gkikas
Atmos. Chem. Phys., 22, 15469–15488,Short summary
Using a clustering method developed in the field of artificial neural networks, we identify four typical dust transport patterns across the Sierra Nevada, associated with the mesoscale and regional-scale wind circulations. Our results highlight the connection between dust transport and dominant weather patterns, which can be used to understand dust transport in a changing climate.
Anbao Zhu, Haiming Xu, Jiechun Deng, Jing Ma, and Shaofeng Hua
Atmos. Chem. Phys., 22, 15425–15447,Short summary
This study demonstrates the instant and delayed effects of biomass burning (BB) aerosols on precipitation over the Indochina Peninsula (ICP). The convection suppression due to the BB aerosol-induced stabilized atmosphere dominates over the favorable water-vapor condition induced by large-scale circulation responses, leading to an overall reduced precipitation in March, while the delayed effect promotes precipitation from early April to mid April due to the anomalous atmospheric circulations.
Wenjie Zhang, Hong Wang, Xiaoye Zhang, Liping Huang, Yue Peng, Zhaodong Liu, Xiao Zhang, and Huizheng Che
Atmos. Chem. Phys., 22, 15207–15221,Short summary
Aerosol–cloud interaction (ACI) is first implemented in the atmospheric chemistry system GRAPES_Meso5.1/CUACE. ACI can improve the simulated cloud, temperature, and precipitation under haze pollution conditions in Jing-Jin-Ji in China. This paper demonstrates the critical role of ACI in current numerical weather prediction over the severely polluted region.
Santeri Tuovinen, Runlong Cai, Veli-Matti Kerminen, Jingkun Jiang, Chao Yan, Markku Kulmala, and Jenni Kontkanen
Atmos. Chem. Phys., 22, 15071–15091,Short summary
We compare observed survival probabilities of atmospheric particles from Beijing, China, with survival probabilities based on analytical formulae and model simulations. We find observed survival probabilities under polluted conditions at smaller sizes to be higher, while at larger sizes they are lower than or similar to theoretical survival probabilities. Uncertainties in condensation sink and growth rate are unlikely to explain higher-than-predicted survival probabilities at smaller sizes.
Suvarna Fadnavis, Bernd Heinold, Thazhe Purayil Sabin, Anne Kubin, Wan Ting Katty Huang, Alexandru Rap, and Rolf Müller
The influence of COVID-19 lockdown on the Himalayas caused increases in snow-cover and a decrease in runoff, ultimately leading to an enhanced snow-water-equivalent. Our findings highlight that out of the two processes causing a retreat of Himalayan glaciers: (1) a slow response by global climate change and (2) fast response of local air pollution, a policy action on the latter is more likely to be within reach of possible policy action to help billons of people in south Asia.
Stephanie Woodward, Alistair A. Sellar, Yongming Tang, Marc Stringer, Andrew Yool, Eddy Robertson, and Andy Wiltshire
Atmos. Chem. Phys., 22, 14503–14528,Short summary
We describe the dust scheme in the UKESM1 Earth system model and show generally good agreement with observations. Comparing with the closely related HadGEM3-GC3.1 model, we show that dust differences are not only due to inter-model differences but also to the dust size distribution. Under climate change, HadGEM3-GC3.1 dust hardly changes, but UKESM1 dust decreases because that model includes the vegetation response which, in our models, has a bigger impact on dust than climate change itself.
Yang Yang, Liangying Zeng, Hailong Wang, Pinya Wang, and Hong Liao
Atmos. Chem. Phys., 22, 14489–14502,Short summary
Using an aerosol–climate model, dust pollution in China affected by different spatial and temporal types of El Niño are examined. Both eastern and central Pacific El Niño and short-duration El Niño increase winter dust concentrations over northern China, while long-duration El Niño decreases concentrations. Only long-duration El Niño events can significantly affect dust over China in the following spring. This study has profound implications for air pollution control and dust storm prediction.
Xurong Wang, Qiaoqiao Wang, Maria Prass, Christopher Pöhlker, Daniel Moran-Zuloaga, Paulo Artaxo, Jianwei Gu, Ning Yang, Xiajie Yang, Jiangchuan Tao, Juan Hong, Nan Ma, Yafang Cheng, Hang Su, and Meinrat O. Andreae
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
In this work, with optimized particle mass size distribution, we well captured observed AOD and coarse aerosol concentrations over source and/or receptor regions, demonstrating the well performance in simulating the export of African dust towards the Amazon Basin. In addition to the factors controlling the trans-Atlantic transport of African dust, the study also investigated the impact of African dust over the Amazon Basin including the nutrient inputs associated with dust deposition.
Robin Stevens, Andrei Ryjkov, Mahtab Majdzadeh, and Ashu Dastoor
Atmos. Chem. Phys., 22, 13527–13549,Short summary
Absorbing particles like black carbon can be coated with other matter. How much radiation these particles absorb depends on the coating thickness. The removal of these particles by clouds and rain depends on the coating composition. These effects are important for both climate and air quality. We implement a more detailed representation of these particles in an air quality model which accounts for both coating thickness and composition. We find a significant effect on particle concentrations.
Fan Wang, Gregory R. Carmichael, Jing Wang, Bin Chen, Bo Huang, Yuguo Li, Yuanjian Yang, and Meng Gao
Atmos. Chem. Phys., 22, 13341–13353,Short summary
Unprecedented urbanization in China has led to serious urban heat island (UHI) issues, exerting intense heat stress on urban residents. We find diverse influences of aerosol pollution on urban heat island intensity (UHII) under different circulations. Our results also highlight the role of black carbon in aggravating UHI, especially during nighttime. It could thus be targeted for cooperative management of heat islands and aerosol pollution.
Qianqian Song, Zhibo Zhang, Hongbin Yu, Jasper F. Kok, Claudia Di Biagio, Samuel Albani, Jianyu Zheng, and Jiachen Ding
Atmos. Chem. Phys., 22, 13115–13135,Short summary
This study developed a dataset that enables us to efficiently calculate dust direct radiative effect (DRE, i.e., cooling or warming our planet) for any given dust size distribution in addition to three sets of dust mineral components and two dust shapes. We demonstrate and validate the method of using this dataset to calculate dust DRE. Moreover, using this dataset we found that dust mineral composition is a more important factor in determining dust DRE than dust size and shape.
Eleni Drakaki, Vassilis Amiridis, Alexandra Tsekeri, Antonis Gkikas, Emmanouil Proestakis, Sotirios Mallios, Stavros Solomos, Christos Spyrou, Eleni Marinou, Claire L. Ryder, Demetri Bouris, and Petros Katsafados
Atmos. Chem. Phys., 22, 12727–12748,Short summary
State-of-the-art atmospheric dust models have limitations in accounting for a realistic dust size distribution (emission, transport). We modify the parameterization of the mineral dust cycle by including particles with diameter >20 μm, as indicated by observations over deserts. Moreover, we investigate the effects of reduced settling velocities of dust particles. Model results are evaluated using airborne and spaceborne dust measurements above Cabo Verde.
Chenguang Tian, Xu Yue, Jun Zhu, Hong Liao, Yang Yang, Yadong Lei, Xinyi Zhou, Hao Zhou, Yimian Ma, and Yang Cao
Atmos. Chem. Phys., 22, 12353–12366,Short summary
We quantify the impacts of fire aerosols on climate through direct, indirect, and albedo effects. In atmosphere-only simulations, we find global fire aerosols cause surface cooling and rainfall inhibition over many land regions. These fast atmospheric perturbations further lead to a reduction in regional leaf area index and lightning activities. By considering the feedback of fire aerosols on humidity, lightning, and leaf area index, we predict a slight reduction in fire emissions.
Yanxing Wu, Run Liu, Yanzi Li, Junjie Dong, Zhijiong Huang, Junyu Zheng, and Shaw Chen Liu
Atmos. Chem. Phys., 22, 11945–11955,Short summary
Multiple linear regression (MLR) analyses often interpret the correlation coefficient (r2) as the contribution of an independent variable to the dependent variable. Since a good correlation does not imply a causal relationship, we propose that r2 should be interpreted as the maximum possible contribution. Moreover, MLR results are sensitive to the length of time analyzed; long-term analysis gives a more accurate assessment because of its additional constraints.
Mengying Li, Shaocai Yu, Xue Chen, Zhen Li, Yibo Zhang, Zhe Song, Weiping Liu, Pengfei Li, Xiaoye Zhang, Meigen Zhang, Yele Sun, Zirui Liu, Caiping Sun, Jingkun Jiang, Shuxiao Wang, Benjamin N. Murphy, Kiran Alapaty, Rohit Mathur, Daniel Rosenfeld, and John H. Seinfeld
Atmos. Chem. Phys., 22, 11845–11866,Short summary
This study constructed an emission inventory of condensable particulate matter (CPM) in China with a focus on organic aerosols (OAs), based on collected CPM emission information. The results show that OA emissions are enhanced twofold for the years 2014 and 2017 after the inclusion of CPM in the new inventory. Sensitivity cases demonstrated the significant contributions of CPM emissions from stationary combustion and mobile sources to primary, secondary, and total OA concentrations.
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We studied the monthly-scale climate response to COVID-19 aerosol emission reductions during January–May 2020 using climate models. Our results show global temperature and rainfall anomalies driven by circulation changes. The climate patterns reverse polarity from JF to MAM due to a shift in the main SO2 reduction region from China to India. This real-life example of rapid climate adjustments to abrupt, regional aerosol emission reduction has large implications for future climate projections.
We studied the monthly-scale climate response to COVID-19 aerosol emission reductions during...