Cross-Sectional View of Atmospheric Aerosols over an Urban Location in Central India

Abstract

Surface, column and vertically resolved variations of physical and optical properties of atmospheric aerosol over Hyderabad, a tropical urban location in central India are explored on the basis of ground based and satellite retrieved data. Annual mean aerosol optical depth (τ) observed with Microtops sun-photometer is 0.61 ± 0.07 and seasonally it varied from 0.71 ± 0.06 in pre-monsoon to 0.55 ± 0.05 in winter. Aerosol types are categorized based on Ångström exponent (α) and τ relations; revealed that the study region is dominated by mixed type (MT) aerosol followed by urban/industrial aerosols under high τ (HUI) category. A consistent diurnal variation of black carbon (BC) is observed irrespective of seasonal variation with annual BC mass concentration is found to be 9.7 ± 1.9 µg m -3. During Telangana Survey day, which was the least pollutant day showed a reduction of 75% BC concentration during day time in comparison to five years average values, indicating the influence of anthropogenic effect over Hyderabad. Vertical information's on aerosol are analyzed using Cloud Aerosol Lidar Pathfinder Satellite Observations (CALIPSO) and ground based Lidar (LAMP) data. LAMP data analysis shows a significant elevated aerosol layer up to 4 km during pre-monsoon while aerosols are confined below 3 km during post-monsoon and winter. Long term CALIPSO observations revealed that during postmonsoon to winter, the study area is dominated (~60%) by 'urban' aerosol; while during pre-monsoon period ~75% of the aerosol type belongs to 'dusty mix' category. A decline in short wave flux at the top of the atmosphere (0.66 Wm -2 yr -1 ) is observed, as revealed by long term Clouds and Earths Radiant Energy System (CERES) data analysis with higher decline rate observed in winter (1 Wm -2 yr -1 ) followed by pre-monsoon (0.8 Wm -2 yr -1 ).

Emission of black carbon in heavy traffic areas of Jamshedpur and Ranchi: Risk exposure to humans

“…In this paper, we compared the BC mass concentration of JSR and RNC with other cities of India. The mean BC mass concentration reported at JSR (15.87 μgm −3 ; Present study) was found to be higher as compared to Agra 29 9.5 μgm −3 , Ahmedabad 30 8.3 μgm −3 ; Dhanbad 11 6.5 μgm −3 ;, Guwahati 31 7.2 μgm −3 , Hyderabad 32 9.7 μgm −3 , Visakhapatam 33 4.8 μgm −3 , Kolkata 34 5.0 μgm −3 , Ranchi 35 8.5 μgm −3 ; New Delhi 36 17.4 μgm −3 , Patana 37 9.1 μgm −3 , Pune 38 13.8 μgm −3 , Srinagar 39 6.0 μgm −3 , Tirupati 40 1.0 μgm −3 , Varanasi 35 μgm −3 ;Present study). And BC concentration reported at present study sites (JSR and RNC) was found to be low as compared to Kharagpur 33 21.0 μgm −3 , National Capital Territory 41 33.9 μgm −3 and Raipur 42 23.0 μgm −3 .…”