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Author

Y. B. Kumar

Bio: Y. B. Kumar is an academic researcher from National Atmospheric Research Laboratory. The author has contributed to research in topics: Mass concentration (chemistry) & Air mass. The author has an hindex of 1, co-authored 1 publications receiving 42 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, one year measurement of vertical profiles of volume backscatter and extinction coefficient, aerosol optical depth (AOD), mass concentration of black carbon (BC) and composite aerosol along with thermodynamic structure of the atmosphere has been carried out over an urban tropical location of Hyderabad (17.47°N, 78.58°E), India, during April 2009 to March 2010.
Abstract: [1] One year measurement of vertical profiles of volume backscatter and extinction coefficient, aerosol optical depth (AOD), mass concentration of black carbon (BC) and composite aerosol along with thermodynamic structure of the atmosphere has been carried out over an urban tropical location of Hyderabad(17.47°N, 78.58°E), India, during April 2009 to March 2010. The mean mixing layer height (MLH) exhibits large seasonality exceeding 4 km in pre-monsoon period whereas in winter it comes down to ~1.5 km with an annual mean value of 2.35 ± 1.02 km. Surface BC mass fraction (FBC) shows marked seasonal variation from winter (13 ± 1.9%), pre-monsoon (8.19 ± 2.16%), monsoon (7.3 ± 1.8%) to post-monsoon (11.8 ± 0.18%). The profiles of volume backscatter and extinction coefficients reveal presence of elevated aerosol layers from 2 to 4 km and strong oscillations during pre-monsoon (March–May) and monsoon (June–September) seasons, respectively, while in post-monsoon (October–November) and winter (December–February), the aerosols are well within the lower boundary layer and also exhibit a drastic decrease with increasing altitude. These elevated aerosol layers and vertical distribution appear to be closely linked to the thermodynamic structure of the atmosphere. The aerosol optical properties in conjunction with air mass back trajectory analysis indicate that the observed elevated aerosol layers during pre-monsoon and monsoon could contain significant fraction of coarse mode particles with a mix of dust and marine aerosols. Further analysis reveals that the aerosols within atmospheric boundary layer (ABL) dominate the column aerosol loading with ABL-AOD contributing to ~77.7 ± 17.0%, with significant seasonal variation from winter (86.2 ± 13.1%), pre-monsoon (76.6 ± 12.8%), monsoon (54.2 ± 15.6%) to post monsoon (80.8 ± 14.8%). Seasonal variation of ABL-AOD and BC mass fraction follows similar pattern in the ABL indicating that BC may be an important contributor to the ABL aerosol loading.

50 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the aerosol episode (AE) days and examined the modification in aerosol properties and radiative forcing during the period 2001-2010 based on Kanpur-AERONET sun photometer data.

100 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the time variability of black carbon (BC) aerosols over different timescales (daily, weekly and annual) over a tropical urban location Hyderabad in India using seven channel portable Aethalometer.

67 citations

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TL;DR: In this paper, the authors developed empirical models for PM10 estimation from space over Malaysia using aerosol optical depth (AOD550) and meteorological (surface temperature, relative humidity and atmospheric stability) data (retrieved or estimated) from Moderate Resolution Imaging Spectroradiometer (MODIS) during the period 2007-2011.

64 citations

Journal ArticleDOI
TL;DR: In this paper, the mass concentrations of black carbon (BC) and elemental carbon (EC) from different emissions in the Indo-Gangetic plain (IGP) were compared using optical (Aethalometer; 880 nm) and thermo-optical technique (EC-OC analyzer; 678 nm), respectively.
Abstract: We compare the mass concentrations of black carbon (BC) and elemental carbon (EC) from different emissions in the Indo-Gangetic Plain (IGP), using optical (Aethalometer; 880 nm) and thermooptical technique (EC-OC analyzer; 678 nm), respectively. The fractional contribution of BC mass concentration measured at two different channels (370 and 880 nm), OC/EC ratio, and non-sea-salt K

63 citations

Journal ArticleDOI
TL;DR: The ground and vertical profiles of particulate matter (PM) were mapped as part of a pilot study using a Tethered balloon within the lower troposphere (1000m) during the foggy episodes in the winter season of 2015-16 in New Delhi, India to suggest the need for immediate, stringent measures to improve the regional air quality in the northern India.

59 citations