Radiative effects of black carbon aerosols on Indian monsoon: a study using WRF-Chem model

2017 ◽  
Vol 132 (1-2) ◽  
pp. 115-134 ◽  
Author(s):  
Pramod Soni ◽  
Sachchida Nand Tripathi ◽  
Rajesh Srivastava
Keyword(s):  
Black Carbon ◽  
Indian Monsoon ◽  
Radiative Effects ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

scholarly journals A global modeling study on carbonaceous aerosol microphysical characteristics and radiative effects

2010 ◽  
Vol 10 (15) ◽  
pp. 7439-7456 ◽  
Author(s):  
S. E. Bauer ◽  
S. Menon ◽  
D. Koch ◽  
T. C. Bond ◽  
K. Tsigaridis
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Radiative Flux ◽  
Radiative Effects ◽  
Carbonaceous Particle ◽  
Flux Change ◽  
Aerosol Effects ◽  
The Impact ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Abstract. Recently, attention has been drawn towards black carbon aerosols as a short-term climate warming mitigation candidate. However the global and regional impacts of the direct, indirect and semi-direct aerosol effects are highly uncertain, due to the complex nature of aerosol evolution and the way that mixed, aged aerosols interact with clouds and radiation. A detailed aerosol microphysical scheme, MATRIX, embedded within the GISS climate model is used in this study to present a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative effects. Our best estimate for net direct and indirect aerosol radiative flux change between 1750 and 2000 is −0.56 W/m2. However, the direct and indirect aerosol effects are quite sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative flux change can vary between −0.32 to −0.75 W/m2 depending on these carbonaceous particle properties at emission. Taking into account internally mixed black carbon particles let us simulate correct aerosol absorption. Absorption of black carbon aerosols is amplified by sulfate and nitrate coatings and, even more strongly, by organic coatings. Black carbon mitigation scenarios generally showed reduced radiative fluxeswhen sources with a large proportion of black carbon, such as diesel, are reduced; however reducing sources with a larger organic carbon component as well, such as bio-fuels, does not necessarily lead to a reduction in positive radiative flux.

scholarly journals Effects of Black Carbon Aerosols on the Indian Monsoon

2008 ◽  
Vol 21 (12) ◽  
pp. 2869-2882 ◽  
Author(s):  
Gerald A. Meehl ◽  
Julie M. Arblaster ◽  
William D. Collins
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Bay Of Bengal ◽  
Indian Monsoon ◽  
The Tibetan Plateau ◽  
Bc Aerosols ◽  
Carbon Aerosols ◽  
Sst Gradient ◽  
Precipitation Trends ◽  
Black Carbon Aerosols

Abstract A six-member ensemble of twentieth-century simulations with changes to only time-evolving global distributions of black carbon aerosols in a global coupled climate model is analyzed to study the effects of black carbon (BC) aerosols on the Indian monsoon. The BC aerosols act to increase lower-tropospheric heating over South Asia and reduce the amount of solar radiation reaching the surface during the dry season, as noted in previous studies. The increased meridional tropospheric temperature gradient in the premonsoon months of March–April–May (MAM), particularly between the elevated heat source of the Tibetan Plateau and areas to the south, contributes to enhanced precipitation over India in those months. With the onset of the monsoon, the reduced surface temperatures in the Bay of Bengal, Arabian Sea, and over India that extend to the Himalayas act to reduce monsoon rainfall over India itself, with some small increases over the Tibetan Plateau. Precipitation over China generally decreases due to the BC aerosol effects. There is a weakened latitudinal SST gradient resulting from BC aerosols in the model simulations as seen in the observations, and this is present in the multiple-forcings experiments with the Community Climate System Model, version 3 (CCSM3), which includes natural and anthropogenic forcings (including BC aerosols). The BC aerosols and consequent weakened latitudinal SST gradient in those experiments are associated with increased precipitation during MAM in northern India and over the Tibetan Plateau, with some decreased precipitation over southwest India, the Bay of Bengal, Burma, Thailand, and Malaysia, as seen in observations. During the summer monsoon season, the model experiments show that BC aerosols have likely contributed to observed decreasing precipitation trends over parts of India, Bangladesh, Burma, and Thailand. Analysis of single ensemble members from the multiple-forcings experiment suggests that the observed increasing precipitation trends over southern China appear to be associated with natural variability connected to surface temperature changes in the northwest Pacific.

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