Abstract
Abstract During the pre-monsoon season (April–June), the Indo-Gangetic Basin (IGB) suffers from frequent and intense dust storms originated from the arid and desert regions of southwest Asia (Iran, Afghanistan), Arabia and Thar desert blanketing IGB and Himalayan foothills. The present study examines the columnar and vertical aerosol characteristics and estimates the shortwave (0.25–4.0 μm) aerosol radiative forcing (ARF) and atmospheric heating rates over Kanpur, central IGB, during three intense dust-storm events in the pre-monsoon season of 2010. MODIS images, meteorological and AERONET observations clearly show that all the dust storms either originated from the Thar desert or transported over, under favorable meteorological conditions (low pressure and strong surface winds) affecting nearly the whole IGB and modifying the aerosol loading and characteristics (Angstrom exponent, single scattering albedo, size distribution and refractive index). CALIPSO observations reveal the presence of high-altitude (up to 3–5 km) dust plumes that strongly modify the vertical aerosol profile and are transported over Himalayan foothills with serious climate implications (atmospheric warming, enhanced melting of glaciers). Shortwave ARF calculations over Kanpur using SBDART model show large negative forcing values at the surface (−93.27, −101.60 and −66.71 W m −2 ) during the intense dusty days, associated with planetary (top of atmosphere) cooling (−18.16, −40.95, −29.58 W m −2 ) and significant atmospheric heating (75.11, 60.65, 37.13 W m −2 ), which is translated to average heating rates of 1.57, 1.41 and 0.78 K day −1 , respectively in the lower atmosphere (below ∼3.5 km). The ARF estimates are in satisfactory agreement with the AERONET ARF retrievals over Kanpur.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.