Chemical Characterization of Meltwater from East Rathong Glacier Vis-à-Vis Western Himalayan Glaciers

Ice and meltwater samples from Rathong glacier and its pro-glacial stream Rathong chu, were collected during late winter season. Samples were analyzed to study the chemical composition, weathering, and geochemical processes in ice and meltwater at high altitudes. This study elucidate the variation of major cations (Li⁺, Mg²⁺, NH₄ ⁺, K⁺, Na⁺, Ca²⁺) and major anions (PO₄ ³⁻, F⁻, NO₂ ⁻, Cl⁻, SO₄ ²⁻, NO₃ ⁻) with respect to ionic concentration reported for glaciers in western Himalaya  High correlation between Ca²⁺ and Mg²⁺, the contribution of (Ca²⁺ + Mg²⁺) to the total cations and high value of [(Ca²⁺ + Mg²⁺)/(Na⁺ + K⁺)] ratio suggests that the major source of dissolved ions in the meltwater is carbonate weathering. Enrichment of samples with NO₃ ⁻ and NH₄ ⁺ suggests that scavenging of HNO₃ present in the atmosphere is a major contributor for these ions. High average value of Na⁺/Cl⁻ and K⁺/Cl⁻ ratio suggest that marine aerosols are not the only contributor to ionic composition. R-mode factor analysis was performed to understand the contribution of geochemical weathering and atmosphere in accumulating major cations and anions in ice and meltwater, which suggests that a majority of ions were from chemical weathering and post-depositional sources.