The Fast Response of the Atmospheric Water Cycle to Anthropogenic Black Carbon Aerosols during Summer in East Asia

2021 ◽  
Vol 34 (8) ◽  
pp. 3049-3065
Author(s):  
Chen Pan ◽  
Bin Zhu ◽  
Chenwei Fang ◽  
Hanqing Kang ◽  
Zhiming Kang ◽  
...  
Keyword(s):  
East Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Water Cycle ◽  
Tropical Indian Ocean ◽  
Fast Response ◽  
Southwest Monsoon ◽  
Northwest Pacific ◽  
Atmospheric Water ◽  
Study Results

Abstract Studies of the climate effects of black carbon (BC) in East Asia are not abundant and the effects remain uncertain. Using the Community Earth System Model version 1 (CESM1) with Peking University’s emissions data, the fast response of the atmospheric water cycle to anthropogenic BC during summer in East Asia is investigated in this study. Results show that the CESM1-simulated BC concentration and its direct effective radiative forcing are comparable to observations. With the combination of aerosol–radiation interaction (ARI) and non-aerosol–radiation interaction (including aerosol–cloud interaction and surface albedo effects), anthropogenic BC induces a “wetter south and drier north” pattern over East Asia during summer. Also, anthropogenic BC affects the summer precipitation primarily through changing moisture transport rather than altering local evaporation over East Asia. Using the self-developed atmospheric water tracer method, the responses of dominant moisture sources [the tropical Indian Ocean (TIO) and northwest Pacific] to anthropogenic BC are investigated. Results show that the moisture originating from southwest monsoon-related sources (especially the TIO) is more responsive to anthropogenic BC effects over East Asia. In particular, differing from total precipitation, TIO-supplied precipitation shows a significant response to the ARI of anthropogenic BC over East Asia. Process analyses show that anthropogenic BC affects the southwest monsoon-related moisture supplies primarily via advection, deep convection, and cloud macrophysics. Interestingly, the anthropogenic BC-induced changes of TIO-supplied water vapor in these three processes are all dominated by the ARI over East Asia.

scholarly journals A GCM study of the response of the atmospheric water cycle of West Africa and the Atlantic to Saharan dust radiative forcing

2009 ◽  
Vol 27 (10) ◽  
pp. 4023-4037 ◽  
Author(s):  
K. M. Lau ◽  
K. M. Kim ◽  
Y. C. Sud ◽  
G. K. Walker
Keyword(s):  
West Africa ◽  
Radiative Forcing ◽  
Large Scale ◽  
Water Cycle ◽  
Deep Convection ◽  
Saharan Dust ◽  
Caribbean Region ◽  
Atmospheric Water ◽  
The West ◽  
Dust Layer

Abstract. The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence of an "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summer, as a result of large-scale atmospheric feedback triggered by absorbing dust aerosols, rainfall and cloudiness are enhanced over the West Africa/Eastern Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while longwave has the opposite response. The elevated dust layer warms the air over West Africa and the eastern Atlantic. As the warm air rises, it spawns a large-scale onshore flow carrying the moist air from the eastern Atlantic and the Gulf of Guinea. The onshore flow in turn enhances the deep convection over West Africa land, and the eastern Atlantic. The condensation heating associated with the ensuing deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in a northward shift of the West Africa precipitation over land, increased low-level westerly flow over West Africa at the southern edge of the dust layer, and a near surface westerly jet underneath the dust layer over the Sahara. The dust radiative forcing also leads to significant changes in surface energy fluxes, resulting in cooling of the West African land and the eastern Atlantic, and warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at 0.95 or higher.

scholarly journals Wet removal of black carbon in Asian outflow: Aerosol Radiative Forcing in East Asia (A-FORCE) aircraft campaign

2012 ◽  
Vol 117 (D3) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. Oshima ◽  
Y. Kondo ◽  
N. Moteki ◽  
N. Takegawa ◽  
M. Koike ◽  
...  
Keyword(s):  
East Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Aerosol Radiative Forcing ◽  
Aerosol Radiative ◽  
Wet Removal

scholarly journals Source apportionment of atmospheric water over East Asia – a source tracer study in CAM5.1

2016 ◽  
Author(s):  
Chen Pan ◽  
Bin Zhu ◽  
Jinhui Gao ◽  
Hanqing Kang
Keyword(s):  
East Asia ◽  
Source Apportionment ◽  
Water Vapour ◽  
South China ◽  
Source Region ◽  
Northwest Pacific ◽  
Small Contribution ◽  
Atmospheric Water ◽  
Transport Pathway ◽  
Moisture Source

Abstract. The atmospheric water tracer (AWT) method is implemented in the Community Atmosphere Model version 5.1 (CAM5.1) to quantitatively identify the contributions of various source regions to precipitation and water vapour over East Asia. Compared to other source apportionment methods, the AWT method was developed based on detailed physical parameterizations, and can therefore trace the behaviour of atmospheric water substances directly and exactly. According to the simulation, the north Indian Ocean (NIO) is the dominant oceanic moisture source region for precipitation over the Yangtze River Valley (YRV) and South China (SCN) in summer, while the Northwest Pacific (NWP) dominates during other seasons. Evaporation over the South China Sea (SCS) is responsible for only 2.8–4.2 % of summer precipitation over the YRV and SCN. In addition, the Indo-China Peninsula is an important terrestrial moisture source region (annual contribution of ~ 10 %). The overall relative contribution of each source region to the water vapour amount is similar to the corresponding contribution to precipitation over the YRV and SCN. A case study for the SCS shows that only a small part (≤ 5.8 %) of water vapour originates from local evaporation, while much more water vapour is supplied by the NWP and NIO. In addition, because evaporation from the SCS represents only a small contribution to the water vapour over the YRV and SCN in summer, the SCS mainly acts as a water vapour transport pathway where moisture from the NIO and NWP meet.

Interaction between the Black Carbon Aerosol Warming Effect and East Asian Monsoon

2020 ◽  
Author(s):  
Bingliang Zhuang ◽  
Tijian Wang ◽  
Shu Li ◽  
Min Xie ◽  
Mengmeng Li ◽  
...  
Keyword(s):  
East Asia ◽  
Black Carbon ◽  
South China ◽  
Radiative Forcing ◽  
Asian Monsoon ◽  
Meridional Circulation ◽  
East Asian Monsoon ◽  
Regional Climate ◽  
East Asian ◽  
Black Carbon Aerosol

<p>Black carbon aerosol (BC) has a significant influence on regional climate changes due to its warming effect. Such changes will feedback to BC loadings. Here, the interactions between the BC warming effect and East Asian monsoon (EAM) in both winter (EAWM) and summer (EASM) are investigated using a regional climate model RegCM4, which essentially captures the EAM features and the BC variations in China. The seasonal mean BC optical depth is 0.021 over East Asia during winter, which is 10.5% higher than that during summer. Nevertheless, the BCs direct radiative forcing is 32% stronger during summer (+1.85 W/m<sup>2</sup>). The BC direct effect would induce lower air to warm by 0.11-0.12 K, which causes an meridional circulation anomaly associated with a cyclone at 20-30 <sup>o</sup>N and southerly anomalies at 850 hPa over East Asia. Consequently, the EAM circulation is weakened during winter but enhanced during summer. Precipitation is likely increased, especially in south China during summer (by 3.73%). Compared to BC changes due to EAM interannual variations, BC changes due to its warming effect are as important, but weaker. BC surface concentrations are decreased by 1~3% during both winter and summer, by 1~3%, while the columnar BC is increased in south China during winter. During the strongest monsoon years, the BC loadings are higher at lower latitudes than those during the weakest years, resulting in more southerly meridional circulation anomalies and BC feedbacks during both winter and summer. However, the interactions between the BC warming effect and EAWM/EASM are more intense during the weakest monsoon years.</p>

Interaction between the Black Carbon Aerosol Warming Effect and East Asian Monsoon Using RegCM4

2018 ◽  
Vol 31 (22) ◽  
pp. 9367-9388 ◽  
Author(s):  
B. L. Zhuang ◽  
S. Li ◽  
T. J. Wang ◽  
J. Liu ◽  
H. M. Chen ◽  
...  
Keyword(s):  
East Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Asian Monsoon ◽  
Meridional Circulation ◽  
East Asian Monsoon ◽  
Southern China ◽  
Regional Climate ◽  
East Asian ◽  
Black Carbon Aerosol

AbstractBlack carbon aerosol (BC) has a significant influence on regional climate changes because of its warming effect. Such changes will feed back to BC loadings. Here, the interactions between the BC warming effect and the East Asian monsoon (EAM) in both winter (EAWM) and summer (EASM) are investigated using a regional climate model, RegCM4, that essentially captures the EAM features and the BC variations in China. The seasonal mean BC optical depth is 0.021 over East Asia during winter, which is 10.5% higher than that during summer. Nevertheless, the BC direct radiative forcing is 32% stronger during summer (+1.85 W m−2). The BC direct effect would induce lower air to warm by 0.11–0.12 K, which causes a meridional circulation anomaly associated with a cyclone at 20°–30°N and southerly anomalies at 850 hPa over East Asia. Consequently, the EAM circulation is weakened during winter but enhanced during summer. Precipitation is likely increased, especially in southern China during summer (by 3.73%). Relative to BC changes that result from EAM interannual variations, BC changes from its warming effect are as important but are weaker. BC surface concentrations are decreased by 1%–3% during both winter and summer, whereas the columnar BC is increased in south China during winter. During the strongest monsoon years, the BC loadings are higher at lower latitudes than those during the weakest years, resulting in more southerly meridional circulation anomalies and BC feedbacks during both winter and summer. However, the interactions between the BC warming effect and EAWM/EASM are more intense during the weakest monsoon years.

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 Regional Climate Responses in East Asia to the Black Carbon Aerosol Direct Effects from India and China in Summer

2020 ◽  
Vol 33 (22) ◽  
pp. 9783-9800 ◽  
Author(s):  
Huimin Chen ◽  
Bingliang Zhuang ◽  
Jane Liu ◽  
Shu Li ◽  
Tijian Wang ◽  
...  
Keyword(s):  
East Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Regional Climate ◽  
Cloud Amount ◽  
Climate Feedback ◽  
Direct Effects ◽  
Aerosol Loading ◽  
Highly Nonlinear ◽  
Climate Responses

AbstractBlack carbon (BC) aerosol is a significant and short-lived climate forcing factor. Here, the direct effects of BC emissions from India (IDBC) and China (CNBC) are investigated in East Asia during summer using the state-of-the-art regional climate model RegCM4. In summer, IDBC and CNBC account for approximately 30% and 46% of the total BC emissions in Asia, respectively. The total BC column burden from the two countries and corresponding TOA effective radiative forcing are 1.58 mg m−2 and +1.87 W m−2 in East Asia, respectively. The regional air temperature increases over 0.3 K at maximum and precipitation decreases 0.028 mm day−1 on average. Individually, IDBC and CNBC each can bring about rather different effects on regional climate. IDBC can result in a cooling perturbation accompanied by a substantially increased cloud amount and scattering aerosol loading, resulting in a complex response in the regional precipitation, while CNBC can lead to regional warming, and further induce a local flood in northern China or drought in southern China depending on the opposite but significant circulation anomalies. CNBC plays a dominant role in modulating the regional climate over East Asia due to its higher magnitude, wider coverage, and stronger climate feedback. The direct effect of the total BC from both countries is not a linear combination of that of IDBC and CNBC individually, suggesting that the regional climate responses are highly nonlinear to the emission intensity or aerosol loading, which may be greatly related to the influences of the perturbed atmospheric circulations and climate feedback.

scholarly journals Quantifying sources, transport, deposition, and radiative forcing of black carbon over the Himalayas and Tibetan Plateau

2015 ◽  
Vol 15 (11) ◽  
pp. 6205-6223 ◽  
Author(s):  
R. Zhang ◽  
H. Wang ◽  
Y. Qian ◽  
P. J. Rasch ◽  
R. C. Easter ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
South Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Glacier Retreat ◽  
Modeling Framework ◽  
Near Surface ◽  
Geographical Regions ◽  
Source Receptor Relationships

Abstract. Black carbon (BC) particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions and emission sectors, it is essential to quantify the source–receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. In this study, we use the Community Atmosphere Model version 5 (CAM5) with a newly developed source-tagging technique, nudged towards the MERRA meteorological reanalysis, to characterize the fate of BC particles emitted from various geographical regions and sectors. Evaluated against observations over the HTP and surrounding regions, the model simulation shows a good agreement in the seasonal variation in the near-surface airborne BC concentrations, providing confidence to use this modeling framework for characterizing BC source–receptor relationships. Our analysis shows that the relative contributions from different geographical regions and source sectors depend on season and location in the HTP. The largest contribution to annual mean BC burden and surface deposition in the entire HTP region is from biofuel and biomass (BB) emissions in South Asia, followed by fossil fuel (FF) emissions from South Asia, then FF from East Asia. The same roles hold for all the seasonal means except for the summer, when East Asia FF becomes more important. For finer receptor regions of interest, South Asia BB and FF have the largest impact on BC in the Himalayas and central Tibetan Plateau, while East Asia FF and BB contribute the most to the northeast plateau in all seasons and southeast plateau in the summer. Central Asia and Middle East FF emissions have relatively more important contributions to BC reaching the northwest plateau, especially in the summer. Although local emissions only contribute about 10% of BC in the HTP, this contribution is extremely sensitive to local emission changes. Lastly, we show that the annual mean radiative forcing (0.42 W m−2) due to BC in snow outweighs the BC dimming effect (−0.3 W m−2) at the surface over the HTP. We also find strong seasonal and spatial variation with a peak value of 5 W m−2 in the spring over the northwest plateau. Such a large forcing of BC in snow is sufficient to cause earlier snow melting and potentially contribute to the acceleration of glacier retreat.

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