Brief Communication: Accurate and autonomous snow water equivalent measurements using a cosmic ray sensor on a Himalayan glacier

We analyze snow water equivalent (SWE) measurements from a cosmic ray sensor (CRS) on the lower accumulation area of Mera Glacier (Central Himalaya, Nepal) between November 2019 and November 2021. The CRS aligned well with field observations and revealed accumulation in pre-monsoon and monsoon, followed by ablation in post-monsoon and winter. COSIPY simulations suggest significant surface melting, water percolation and refreezing within the snowpack, consistent with CRS observations, yet liable to be missed by surface mass balance surveys. We conclude that CRS can be used to complement more resource-intensive manual measurements to determine mass fluxes on remote, high-altitude Himalayan glaciers.