Investigations of aerosol black carbon from a semi-urban site in the Indo-Gangetic Plain region

摘要: Long-term (2009-2012) data from ground-based measurements of aerosol black carbon (BC) a semi-urban site, Pantnagar (29.0 degrees N, 79.5 E, 231 m amsl), in the Indo-Gangetic Plain (IGP) near Himalayan foothills are analyzed to study regional characterization. Large variations seen BC at both diurnal and seasonal scales, associated with mesoscale synoptic meteorological processes, local/regional anthropogenic activities. show two peaks (morning evening) arising combined effects atmospheric boundary layer (ABL) dynamics local emissions. The amplitudes as well rates evolution highest winter season, followed by autumn, lowest summer-monsoon. exhibits nearly an inverse relation mixing depth all seasons; being strongest (R-2 = 0.89) weakest 0.33) monsoon (July-August). Unlike BC, co-located optical depths (AOD) absorption spring over IGP, probably due presence higher abundances aerosols (including dust) above ABL (in free troposphere). AOD (500 nm) showed annual peak (>0.6) May-June, dominated coarse mode, while fine mode late autumn early winter. Aerosols profiles CALIPSO values close surface winter/autumn, similar feature whereas altitudes > 2 km, extinction is maximum spring/summer. WRF-Chem model used simulate temporal then compared observed BC. captures most important features but significantly underestimated levels, suggesting improvements varying emissions apart processes. (C) 2015 Elsevier Ltd. All rights reserved.