scholarly journals Trends and source apportionment of aerosols in Europe during 1980–2018

2019 ◽  
Author(s):  
Yang Yang ◽  
Sijia Lou ◽  
Hailong Wang ◽  
Pinya Wang ◽  
Hong Liao
Keyword(s):  
Radiative Forcing ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Comparable Rate ◽  
Near Surface ◽  
Source Regions ◽  
Community Atmosphere Model ◽  
Radiative Impact ◽  
Local Emissions ◽  
Aerosol Source

Abstract. Aerosols have significantly affected health, environment and climate in Europe. Aerosol concentrations have been declining since 1980s in Europe, mainly owing to the reduction of local aerosol and precursor emissions. Emissions from other source regions of the world, which have been changing rapidly as well, may also perturb the historical and future trends of aerosols and change their radiative impact in Europe. This study examines trends of aerosols in Europe during 1980–2018 and quantify contributions from sixteen source regions using the Community Atmosphere Model version 5 with an Explicit Aerosol Source Tagging technique (CAM5-EAST). The simulated near-surface total mass concentration of sulfate, black carbon and primary organic carbon had a 62 % decrease during 1980–2018, of which the majority was contributed by reductions of local emissions in Europe and 8 %–9 % was induced by the decrease in emissions from Russia–Belarus–Ukraine. With the decreases in the fractional contribution of local emissions, aerosols transported from other source regions are increasingly important to air quality in Europe. During 1980–2018, the decrease in sulfate loading leads to a warming effect of 2.0 W m−2 in Europe, with 12 % coming from changes in non-European sources, especially from North America and Russia–Belarus–Ukraine. According to the Shared Socioeconomic Pathways (SSP) scenarios, contributions to the sulfate radiative forcing over Europe from both European local emissions and non-European emissions would decrease at a comparable rate in the next three decades, suggesting that future changes in non-European emissions are as important as European emissions in causing possible regional climate change associated with aerosols in Europe.

scholarly journals Trends and source apportionment of aerosols in Europe during 1980–2018

2020 ◽  
Vol 20 (4) ◽  
pp. 2579-2590 ◽  
Author(s):  
Yang Yang ◽  
Sijia Lou ◽  
Hailong Wang ◽  
Pinya Wang ◽  
Hong Liao
Keyword(s):  
Radiative Forcing ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Comparable Rate ◽  
Near Surface ◽  
Source Regions ◽  
Community Atmosphere Model ◽  
Radiative Impact ◽  
Local Emissions ◽  
Aerosol Source

Abstract. Aerosols have significantly affected health, environment, and climate in Europe. Aerosol concentrations have been declining since the 1980s in Europe, mainly owing to a reduction of local aerosol and precursor emissions. Emissions from other source regions of the world, which have been changing rapidly as well, may also perturb the historical and future trends of aerosols and change their radiative impact in Europe. This study examines trends of aerosols in Europe during 1980–2018 and quantifies contributions from 16 source regions using the Community Atmosphere Model version 5 with Explicit Aerosol Source Tagging (CAM5-EAST). The simulated near-surface total mass concentration of sulfate, black carbon, and primary organic carbon had a 62 % decrease during 1980–2018. The majority of which was contributed to reductions of local emissions in Europe, and 8 %–9 % was induced by a decrease in emissions from Russia–Belarus–Ukraine. With the decreases in the fractional contribution of local emissions, aerosols transported from other source regions are increasingly important for air quality in Europe. During 1980–2018, the decrease in sulfate loading led to a warming effect of 2.0 W m−2 in Europe, with 12 % coming from changes in non-European sources, especially from North America and Russia–Belarus–Ukraine. According to the Shared Socioeconomic Pathways (SSP) scenarios, contributions to the sulfate radiative forcing over Europe from both local European emissions and non-European emissions should decrease at a comparable rate in the next 3 decades, suggesting that future changes in non-European emissions are as important as European emissions for causing possible regional climate change associated with aerosols in Europe.

scholarly journals Simulation of dust aerosol and its regional feedbacks over East Asia using a regional climate model

2008 ◽  
Vol 8 (2) ◽  
pp. 4625-4667 ◽  
Author(s):  
D. F. Zhang ◽  
A. S. Zakey ◽  
X. J. Gao ◽  
F. Giorgi
Keyword(s):  
East Asia ◽  
Regional Climate Model ◽  
Radiative Forcing ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Cooling ◽  
Near Surface ◽  
Dust Aerosols ◽  
Source Regions ◽  
Mass Load

Abstract. The ICTP regional climate model (RegCM3) coupled with a desert dust model is used to simulate the radiative forcing and related climate effects of dust aerosols over East Asia. Two sets of experiments encompassing the main dust producing months, February to May, for 10 years (1997–2006) are conducted and inter-compared, one without (Exp. 1) and one with (Exp. 2) the radiative effects of dust aerosols. The simulation results are evaluated against ground station and satellite data. The model captures the basic observed climatology over the area of interest. The spatial and temporal variations of near surface concentration, mass load, and emission of dust aerosols from the main source regions are reproduced by model, with the main model deficiency being an overestimate of dust amount over the source regions and underestimate downwind of these source areas. Both the top-of-the-atmosphere (TOA) and surface radiative fluxes are decreased by dust and this causes a surface cooling locally up to −1°C. The inclusion of dust radiative forcing leads to a reduction of dust emission in the East Asia source regions, which is mainly caused by an increase in local stability and a corresponding decrease in dust lifting. Our results indicate that dust effects should be included in the assessment of climate change over East Asia.

scholarly journals Incorrect Asian aerosols affecting the attribution and projection of regional climate change in CMIP6 models

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhili Wang ◽  
Lei Lin ◽  
Yangyang Xu ◽  
Huizheng Che ◽  
Xiaoye Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
Impact Analysis ◽  
Climate Model ◽  
Regional Climate ◽  
Eastern China ◽  
Coupled Model ◽  
Regional Climate Change ◽  
Anthropogenic Aerosol ◽  
Wide Range

AbstractAnthropogenic aerosol (AA) forcing has been shown as a critical driver of climate change over Asia since the mid-20th century. Here we show that almost all Coupled Model Intercomparison Project Phase 6 (CMIP6) models fail to capture the observed dipole pattern of aerosol optical depth (AOD) trends over Asia during 2006–2014, last decade of CMIP6 historical simulation, due to an opposite trend over eastern China compared with observations. The incorrect AOD trend over China is attributed to problematic AA emissions adopted by CMIP6. There are obvious differences in simulated regional aerosol radiative forcing and temperature responses over Asia when using two different emissions inventories (one adopted by CMIP6; the other from Peking university, a more trustworthy inventory) to driving a global aerosol-climate model separately. We further show that some widely adopted CMIP6 pathways (after 2015) also significantly underestimate the more recent decline in AA emissions over China. These flaws may bring about errors to the CMIP6-based regional climate attribution over Asia for the last two decades and projection for the next few decades, previously anticipated to inform a wide range of impact analysis.

scholarly journals Influence of anthropogenic aerosols on the Asian monsoon: a case study using the WRF-Chem model

2013 ◽  
Vol 13 (8) ◽  
pp. 21383-21425 ◽  
Author(s):  
X. Jiang ◽  
M. C. Barth ◽  
C. Wiedinmyer ◽  
S. T. Massie
Keyword(s):  
East Asia ◽  
Radiative Forcing ◽  
Asian Monsoon ◽  
Anthropogenic Activities ◽  
Cloud Droplet ◽  
Cloud Base ◽  
Monsoon Precipitation ◽  
Anthropogenic Aerosols ◽  
Source Regions ◽  
Local Emissions

Abstract. Aerosols, in particular those related to anthropogenic activities, including black carbon, organic carbon, and sulfate aerosols, have been found to affect the Asian monsoon through direct and indirect aerosol radiative forcing. In this work, we use the coupled regional Weather Research and Forecasting model with Chemistry (WRF-Chem) to understand how aerosol changes from local emission sources could modulate the Asian monsoon precipitation through aerosol direct and indirect radiative effects. Our modeling results with the consideration of the local emissions show an improvement in simulated monsoon precipitation, when compared to reanalysis data and satellite observations. Aerosols generally induce a reduction in pre-monsoon and monsoon precipitation in East Asia. Over the Indian region, local anthropogenic emissions tend to reduce precipitation in the source regions while slightly increasing precipitation outside of the emission source regions. The increase in precipitation corresponds to a decrease in the cloud base level or lifting condensation level. Analysis of vertical cloud properties suggests that the increased cloud droplet number and prolonged cloud lifetime/reduced precipitation efficiency due to the local aerosol emissions are responsible for the precipitation reduction over East Asia. Aerosols from local emissions also play a very important role in the simulated surface temperature, radiation, and monsoon circulations.

Incorrect Asian aerosols affecting the attribution and projection of regional climate change in CMIP6 models 

2021 ◽  
Author(s):  
Lei Lin ◽  
Zhili Wang ◽  
Yangyang Xu ◽  
Huizheng Che ◽  
Xiaoye Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
Impact Analysis ◽  
Climate Model ◽  
Regional Climate ◽  
Eastern China ◽  
Coupled Model ◽  
Regional Climate Change ◽  
Anthropogenic Aerosol ◽  
Wide Range

<p><span>Anthropogenic aerosol (AA) forcing has been shown as a critical driver of climate change over Asia since the mid-20th century. Here we show that almost all Coupled Model Intercomparison Project Phase 6 (CMIP6) models fail to capture the observed dipole pattern of aerosol optical depth (AOD) trends over Asia during 2006–2014, last decade of CMIP6 historical simulation, due to an opposite trend over eastern China compared with observations. The incorrect AOD trend over China is attributed to problematic AA emissions adopted by CMIP6. There are obvious differences in simulated regional aerosol radiative forcing and temperature responses over Asia when using two different emissions inventories (one adopted by CMIP6; the other from Peking university, a more trustworthy inventory) to driving a global aerosol-climate model separately. We further show that some widely adopted CMIP6 pathways (after 2015) also significantly underestimate the more recent decline in AA emissions over China. These flaws may bring about errors to the CMIP6-based regional climate attribution over Asia for the last two decades and projection for the next few decades, previously anticipated to inform a wide range of impact analysis.</span></p>

scholarly journals Scattering and absorption properties of near-surface aerosol over Gangetic–Himalayan region: the role of boundary-layer dynamics and long-range transport

2015 ◽  
Vol 15 (3) ◽  
pp. 1555-1572 ◽  
Author(s):  
U. C. Dumka ◽  
D. G. Kaskaoutis ◽  
M. K. Srivastava ◽  
P. C. S. Devara
Keyword(s):  
Atmospheric Aerosols ◽  
Radiative Forcing ◽  
Monsoon Circulation ◽  
Absorption Properties ◽  
Near Surface ◽  
Source Regions ◽  
Range Transport ◽  
Boundary Layer Dynamics ◽  
The Ganges

Abstract. Light scattering and absorption properties of atmospheric aerosols are of vital importance for evaluating their types, sources and radiative forcing. This is of particular interest over the Gangetic–Himalayan (GH) region due to uplift of aerosol from the plains to the Himalayan range, causing serious effects on atmospheric heating, glaciology and monsoon circulation. In this respect, the Ganges Valley Aerosol Experiment (GVAX) was initiated in Nainital from June 2011 to March 2012 with the aim of examining the aerosol properties, source regions, uplift mechanisms and aerosol–radiation–cloud interactions. The present study examines the temporal (diurnal, monthly, seasonal) evolution of scattering (σ

Will marine dimethylsulfide emissions amplify or alleviate global warming? A model study

2004 ◽  
Vol 61 (5) ◽  
pp. 826-835 ◽  
Author(s):  
Laurent Bopp ◽  
Olivier Boucher ◽  
Olivier Aumont ◽  
Sauveur Belviso ◽  
Jean-Louis Dufresne ◽  
...  
Keyword(s):  
Global Warming ◽  
Radiative Forcing ◽  
Sulfur Compound ◽  
Cloud Condensation Nuclei ◽  
Regional Climate ◽  
Climate Feedback ◽  
Model Study ◽  
Radiative Impact ◽  
Radiative Perturbation ◽  
First Time

Dimethylsulfide (DMS) is the most abundant volatile sulfur compound at the sea surface and has a strong marine phytoplanktonic origin. Once outgased into the atmosphere, it contributes to the formation of sulfate aerosol particles that affect the radiative budget as precursors of cloud condensation nuclei (CCN). It has been postulated that climate may be partly modulated by variations in DMS production. We test this hypothesis in the context of anthro pogenic climate change and present here, modelled for the first time, an estimate of the radiative impact resulting from changes in DMS air–sea fluxes caused by global warming. At 2× CO2, our model estimates a small increase (3%) in the global DMS flux to the atmosphere but with large spatial heterogeneities (from –15% to 30%). The radiative perturbation resulting from the DMS-induced change in cloud albedo is estimated to be –0.05 W·m–2, which represents only a small negative climate feedback on global warming. However, there are large regional changes, such as a perturbation of up to –1.5 W·m–2 in summer between 40°S and 50°S, that can impact the regional climate. In the Southern Ocean, the radiative impact resulting from changes in the DMS cycle may partly alleviate the radiative forcing resulting from anthropogenic CO2.

scholarly journals Relative Importance of Northern Hemisphere Circulation Modes in Predicting Regional Climate Change

2004 ◽  
Vol 17 (21) ◽  
pp. 4180-4189 ◽  
Author(s):  
Monika Rauthe ◽  
Heiko Paeth
Keyword(s):  
Climate Change ◽  
Northern Hemisphere ◽  
North Atlantic ◽  
North Pacific ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Relative Importance ◽  
Near Surface ◽  
The North ◽  
The North Pacific

Abstract The Northern Hemisphere annular mode (NAM), North Atlantic Oscillation (NAO), and Aleutian low (AL) are known to be the most prominent components of Northern Hemisphere (NH) near-surface climate variability. In a tremendous number of studies, the impact of these circulation features on regional climate has been demonstrated. More recently, research has gone into the connection between the NAO and NAM and into the physical meaning of the latter. However, the relevance of those circulation modes for climatological issues may also be inferred from another nondynamical point of view: their statistical relationship to various climate parameters. This study comprises two steps: 1) qualifying and quantifying the relative importance of NH circulation modes with respect to twentieth-century near-surface temperature and precipitation, using stepwise multiple regression with cross validation; and 2) using predictor–predictand relationships to access the contributions of each circulation mode to regional climate change in the middle of the twenty-first century, given multimodel predictions of the circulation modes' responses to increasing greenhouse gas (GHG) and sulfate aerosol (SUL) concentrations. Altogether, the NAM, NAO, and AL account locally for up to 75% of the total interannual temperature and rainfall variability over NH continents. Over the major part of the NH, the NAM appears to be the most important predictor. In some parts of the North Atlantic, temperature and rainfall are more closely linked to the NAO, while the North Pacific is clearly dominated by the AL dynamics. In general, the NAO and AL have a more regionally confined influence. Climate change experiments mostly predict an intensification of the NAM and AL under GHG+SUL forcing, while the NAO response is much less consistent with different models and generally undergoes no long-term changes. This leads to substantial contributions to temperature and rainfall anomalies, especially over the NH landmasses. Temperature changes amount to ±1 K over large parts of Russia, North America, and the North Pacific. The major precipitation changes occur over the North Pacific, the North Atlantic, and Scandinavia. This circulation-induced contribution accounts for a considerable part of total expected change in these regions. Given its distinct trend, the NAM plays the main role, except over the Pacific Ocean and North America, where the AL is driving regional climate anomalies. Thus, whether physically relevant or not, the NAM is an appropriate statistical indicator of NH regional climate change.

scholarly journals Source attribution of black carbon and its direct radiative forcing in China

2016 ◽  
Author(s):  
Yang Yang ◽  
Hailong Wang ◽  
Steven J. Smith ◽  
Po-Lun Ma ◽  
Philip J. Rasch
Keyword(s):  
Air Quality ◽  
East Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
North China ◽  
Local Source ◽  
Near Surface ◽  
Direct Radiative Forcing ◽  
Non Local ◽  
Local Emissions

Abstract. The source attributions for mass concentration, haze formation, transport, and direct radiative forcing of black carbon (BC) in various regions of China are quantified in this study using the Community Earth System Model (CESM) with a source-tagging technique. Anthropogenic emissions are from the Community Emissions Data System that is newly developed for the Coupled Model Intercomparison Project Phase 6 (CMIP6). Over North China where the air quality is often poor, about 90 % of near-surface BC concentration is contributed by local emissions. 30 % of BC concentration over South China in winter can be attributed to emissions from North China and 10 % comes from sources outside China in spring. For other regions in China, BC is largely contributed from non-local sources. We further investigated potential factors that contribute to the poor air quality in China. During polluted days, a net inflow of BC transported from non-local source regions associated with anomalous winds plays an important role in increasing local BC concentrations. BC-containing particles emitted from East Asia can also be transported across the Pacific. Our model results show that emissions from inside and outside China are equally important for the BC outflow from East Asia, while emissions from China account for 7 % of BC concentration and 25 % in column burden in western United States in spring. Radiative forcing estimated shows that 66 % of the annual mean BC direct radiative forcing (2.3 W m−2) in China results from local emissions, and the remaining 34 % are contributed by emissions outside of China. Efficiency analysis shows that reduction in BC emissions over eastern China could benefit more on the regional air quality in China, especially in winter haze season.

scholarly journals Quantifying sources of black carbon in Western North America using observationally based analysis and an emission tagging technique in the Community Atmosphere Model

2015 ◽  
Vol 15 (9) ◽  
pp. 12957-13000
Author(s):  
R. Zhang ◽  
H. Wang ◽  
D. A. Hegg ◽  
Y. Qian ◽  
S. J. Doherty ◽  
...  
Keyword(s):  
North America ◽  
Black Carbon ◽  
Local Source ◽  
Western North America ◽  
Near Surface ◽  
Mixing Ratios ◽  
Source Regions ◽  
Source Type ◽  
Community Atmosphere Model ◽  
Atmosphere Model

Abstract. The Community Atmosphere Model (CAM5), equipped with a technique to tag black carbon (BC) emissions by source regions and types, has been employed to establish source-receptor relationships for atmospheric BC and its deposition to snow over Western North America. The CAM5 simulation was conducted with meteorological fields constrained by reanalysis for year 2013 when measurements of BC in both near-surface air and snow are available for model evaluation. We find that CAM5 has a significant low bias in predicted mixing ratios of BC in snow but only a small low bias in predicted atmospheric concentrations over the Northwest USA and West Canada. Even with a strong low bias in snow mixing ratios, radiative transfer calculations show that the BC-in-snow darkening effect is substantially larger than the BC dimming effect at the surface by atmospheric BC. Local sources contribute more to near-surface atmospheric BC and to deposition than distant sources, while the latter are more important in the middle and upper troposphere where wet removal is relatively weak. Fossil fuel (FF) is the dominant source type for total column BC burden over the two regions. FF is also the dominant local source type for BC column burden, deposition, and near-surface BC, while for all distant source regions combined the contribution of biomass/biofuel (BB) is larger than FF. An observationally based Positive Matrix Factorization (PMF) analysis of the snow-impurity chemistry is conducted to quantitatively evaluate the CAM5 BC source-type attribution. While CAM5 is qualitatively consistent with the PMF analysis with respect to partitioning of BC originating from BB and FF emissions, it significantly underestimates the relative contribution of BB. In addition to a possible low bias in BB emissions used in the simulation, the model is likely missing a significant source of snow darkening from local soil found in the observations.

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