Processes governing the mass balance of Chhota Shigri Glacier (Western Himalaya, India) assessed by point-scale surface energy balance measurements

Abstract

Abstract. Recent studies revealed that Himalayan glaciers have been shrinking at an accelerated rate since the beginning of the 21st century. However the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in-situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July to October 2013) in order to understand the response of mass balance to climate change. Energy balance numerical modeling provides quantification of the surface energy fluxes and identification of the factors affecting glacier mass balance. The computed ablation was validated by stake observations. During summer-monsoon period, net radiation was the primary component of the surface energy balance with 82% of the total heat flux which was complimented with turbulent sensible and latent heat fluxes with a share of 13% and 5%, respectively. A striking feature of energy balance is the positive turbulent latent heat flux, thus condensation or re-sublimation of moist air at the glacier surface takes place, during summer-monsoon period which is characterized by relatively high air temperature, high relative humidity and almost permanent melting surface. The impact of Indian summer monsoon on Chhota Shigri Glacier mass balance has also been assessed. This analysis demonstrates that the intensity of snowfall events during the summer-monsoon season plays a key role on surface albedo, in turn on melting, and thus is among the most important drivers controlling the annual mass balance of the glacier. Summer-monsoon air temperature, controlling the precipitation phase (rain vs. snow and thus albedo), counts, indirectly, also among the most important drivers for the glacier mass balance.

Study of isotopic seasonality to assess the water source of proglacial stream in Chhota Shigri Glaciated Basin, Western Himalaya

“…Surface melts were related quite well with the precipitation as well; for instance, late August/September (August 30–September 2, 2016) where temperature was ~2°C and most of the precipitation occurred as snowfall in the glacier surface (snowfall observed during fieldwork), which increase the surface albedo; in turn, a sudden check in surface melting occurred as evident in the Figure . Such pattern of snowfall role in glacier melting is significant if the snowfall occurs frequently, which restricts the glacier from high melting in summer and leads to a positive or near zero annual mass balance of this glacier as noted in one of our previous study (Azam et al, ).…”

“…Mean monthly relative humidity on the other hand was observed to be highest in summer monsoon season (68%), whereas the same was 42%, 39%, and 52% during winter, postmonsoon, and premonsoon period. Chhota Shigri receives majority of its precipitation during winter season (71%), whereas summer, premonsoon, and postmonsoon only receives 12%, 15%, and 3% of the total annual precipitation, respectively (Azam et al, ; Azam et al, ). This shows that the glacier is winter accumulation type glacier and receives majority of the precipitation through western disturbances.…”

A comparative high-altitude meteorological analysis from three catchments in the Nepalese Himalaya

“…Similar studies are still needed in the Karakoram-Himalaya region, though some short-term studies have been published (Azam et al, 2014b;Fujita, Sakai, & Chhetri, 1997;Immerzeel, Petersen, Ragettli, & Pellicciotti, 2014;Takahashi et al, 1987). This article presents first analyses of high-quality meteorological data-sets recorded in three distinct catchments in the Nepal Himalaya where glaciological monitoring is simultaneously performed.…”

Elevation Change Rates of Glaciers in the Lahaul-Spiti (Western Himalaya, India) during 2000–2012 and 2012–2013

“…A segment is located in the Lahaul-Spiti region of western Himalaya, India. The glaciers in the Lahaul-Spiti receive precipitation throughout the year but majorly during July-September by Indian summer monsoon (ISM) and during January-April by mid-latitude winter westerlies (MLW) [2]. The warming trend of surface air temperature (e.g., 0.46 • per decade during 1971-2007) in western Himalaya is higher than the global average [3].…”