Spatial heterogeneity in near surface aerosol characteristics across the Brahmaputra valley

Journal of Earth system science

Arup Borgohain2³  Binita Pathak1¹  Shyam Sundar Kundu2³  Pradip Kumar Bhuyan1¹  S Sudhakar2³  Mukunda M Gogoi3⁴  Toshihiko Takemura4² 

[1] Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh 786 004, India.$$;Research Institute for Applied Mechanics, Kyushu University 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan.$$;North–East Space Application Centre, Umiam, Shillong, Meghalaya 793 103, India.$$;Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695 022, India.$$

关键词: PM10;    PM2.5;    black carbon;    SPRINTARS;    CWT.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

In order to examine the spatial variability of the aerosol characteristics across the Brahmaputra valley, a land campaign was conducted during late winter (February 3–March 2) 2011. Measurements of particulate matter (PM, PM10, PM2.5) and black carbon (BC) concentrations were made onboard an interior redesigned vehicle. The length of the campaign trail stretched about 700 km, covering the longitude belt of 89.97°–95.55°E and latitude belt of 26.1°–27.6°N, comprising 13 measurement locations. The valley is divided into three sectors longitudinally: western sector (R1: 89.97°–91.75°E), middle sector (R2: 92.5°–94.01°E) and eastern sector (R3: 94.63°–95.55°E). Spatial heterogeneity in aerosol distribution has been observed with higher PM10 and PM2.5 concentrations at the western and middle sectors compared to the eastern sector. The locations in the western sector are found to be rich in BC compared to the other two sectors and there is a gradual decrease in BC concentrations from west to east of the Brahmaputra valley. Two hotspots within the western and middle sectors with high PM and BC concentrations have been identified. The associated physico-optical parameters of PM reveal abundance of PM2.5 aerosols along the entire valley. High population density in the western and middle sectors, together with the contribution of remote aerosols, leads to higher anthropogenic aerosols over those regions. Spectral Radiation-Transport Model for Aerosol Species (SPRINTARS) slightly underestimates the measured PM10 and PM2.5 at the eastern sector while the model overestimates the measurements at a number of locations in the western sector. In general, BC is underestimated by the model. The variation of BC within the campaign trail has not been adequately captured by the model leading to higher variance in the western locations as compared to the middle and eastern locations.

【 授权许可】

Unknown