Measurement of light-absorbing particles in surface snow of central and western Himalayan glaciers: spatial variability, radiative impacts, and potential source regions

Abstract. We collected surface snow samples from three different glaciers – Yala, Thana, and Sachin in the central western Himalayas to understand spatial variability radiative impacts of light-absorbing particles. The Yala Thana Nepal Bhutan, respectively, were selected represent Himalayas. glacier Pakistan was during pre- post-monsoon seasons year 2016. analyzed for black carbon (BC) water-insoluble organic (OC) through thermal optical method. average mass concentrations (BC 2381 ng g−1; OC 3896 dust 101 µg g−1) (Sachin glacier) quite high compared 358 g−1, 904 22 (Yala glacier). difference concentration may be due elevation, age, local pollution sources, meteorological conditions. BC also estimated Weather Research Forecasting (WRF) model coupled with Chemistry (WRF-Chem) simulations at sites sampling periods. Simulations reasonably capture seasonal patterns observed but a relatively smaller magnitude. Absolute albedo Snow, Ice, Aerosol Radiative (SNICAR) model. absolute reduction ranged 0.48 % (Thana September) 24 May) 0.13 5 dust. instantaneous forcing range 0 96.48 25 W m−2, respectively. lowest highest Himalayan glaciers, potential source regions deposited pollutants inferred using WRF-Chem tagged-tracer simulations. Selected mostly affected by long-range transport Middle East Asia; however, mainly south Asia emissions (from Nepal, India, China) especially pre-monsoon season. Overall, west main contributing pollutants.