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The extensive work on the increasing burden of aerosols and resultant climate implications
shows a matter of great concern. In this study, we investigate the aerosol optical depth (AOD)
variations in the Indian Himalayan Region (IHR) between its plains and alpine regions and the
corresponding consequences on the energy balance on the Himalayan glaciers. For this purpose,
AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS, MOD-L3), Aerosol Robotic
Network (AERONET), India, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation
(CALIPSO) were analyzed. Aerosol radiative forcing (ARF) was assessed using the atmospheric
radiation transfer model (RTM) integrated into AERONET inversion code based on the Discrete
Ordinate Radiative Transfer (DISORT) module. Further, air mass trajectory over the entire IHR
was analyzed using a hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model.
We estimated that between 2001 and 2015, the monthly average ARF at the surface (ARFSFC), top
of the atmosphere (ARFTOA), and atmosphere (ARFATM) were −89.6 ± 18.6 Wm−2, −25.2 ± 6.8 Wm−2,
and +64.4 ± 16.5 Wm−2, respectively. We observed that during dust aerosol transport days, the
ARFSFC and TOA changed by −112.2 and −40.7 Wm−2, respectively, compared with low aerosol
loading days, thereby accounting for the decrease in the solar radiation by 207% reaching the surface.
This substantial decrease in the solar radiation reaching the Earth’s surface increases the heating
rate in the atmosphere by 3.1-fold, thereby acting as an additional forcing factor for accelerated
melting of the snow and glacier resources of the IHR.
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