Glacier snowmelt in the Indian central Himalaya is exacerbated by the presence of light-absorbing particles

The activities of the Indo-Gangetic Plain produce vast amounts of particulate matter that is released into the atmosphere. Many of these particles are so-called light-absorbing particles, which can be transported to the nearby Himalayan Mountains – darkening the snow surfaces leading to accelerated snowmelt.

In a series of measurements in the Indian Himalaya, it was recently reported that the deposition of black carbon (a pronounced light-absorbing particle) to the snow can surprisingly well be characterized by a constant for different snow layers. In between the snow layers, there were distinct melt-layers that contained very high amounts of light-absorbing particles. These layers are the result of strong melting that took place during the summers of 2015 and 2016. The measurements further show that another prominent light-absorbing particle, mineral dust, is responsible for about half of the light absorption taking place by the particles in the snow.

The melted snow feeds rivers with fresh water. Therefore studying snowmelt and the causes of it is of great importance in the Himalaya, since millions of people living downstream depend on the water originating from the high-altitude glaciers.

Further information:

Researcher Jonas Svensson, Finnish Meteorological Institute, jonas.svensson@fmi.fi Svensson, J., Ström, J., Honkanen, H., Asmi, E., Dkhar, N. B., Tayal, S., Sharma, V. P., Hooda, R., Leppäranta, M., Jacobi, H.-W., Lihavainen, H., and Hyvärinen, A.: Deposition of light-absorbing particles in glacier snow of the Sunderdhunga Valley, the southern forefront of the central Himalayas, Atmos. Chem. Phys., 21, 2931–2943, https://doi.org/10.5194/acp-21-2931-2021, 2021.