A review of major ionic species and trace elements in the Himalayan cryosphere.

Snow and glacier deposits in the Himalayan cryosphere serve as important archives of atmospheric deposition. This review collates published data on major ions and trace elements in snow and ice from the Western, Central, and Eastern Himalayas and the Tibetan Plateau between 2000 and 2024. The compiled studies show a clear dominance of crustal ions (Ca2⁺ and HCO₃⁻), alongside notable enrichment of trace elements such as Zn, Pb, and Mn, reflecting combined influences of mineral dust and anthropogenic emissions. Spatial patterns reveal consistently higher pollutant concentrations on the southern slopes of the Himalayas, while seasonal variability indicates enhanced accumulation during non-monsoon periods due to efficient snow scavenging. Long-range transport driven by Indian summer monsoons and western disturbances plays a key role in transporting contaminants from South and Central Asia. The review further identifies critical data gaps, particularly in the Eastern Himalayas, and emphasizes the need for expanded, standardized monitoring to better assess future ecological and health risks associated with cryospheric contamination under a changing climate.