Towards understanding various influences on mass balance of the Hoksar Glacier in the Upper Indus Basin using observations

Mass balance of Nehnar glacier from 2000 to 2020, using temperature indexed-IAAR approach

Glacier mass balance is inextricably linked to annual meteorological conditions and is a key indicator for assessing the ice reserves of a glacier. As a result, a number of studies have estimated glacier mass balance using different methods. Here, we have used the improved accumulation area-ratio (IAAR) method to study the mass balance of the Nehnar glacier from 2000 to 2020. This study also aims to study the spatiotemporal behavior and other dynamics of the glacier. Results have shown that the glacier has continuously lost its ice reserves throughout the studied period though at a lower rate since 2010. Its annual specific mass balance has changed from - 50.10 ± 3 cm w.e in 2000 to - 59.46 ± 3 cm w.e. in 2020. The equilibrium line altitude (ELA) of the glacier rose by 90 m and has shifted from 4260 masl in 2000 to 4350 masl in 2020. The glacier has shrunk from an area of 1.64 km2 in 2000 to 1.38 km2 in 2020 losing nearly 16% of its area. The study highlights the need for continued monitoring of glacier mass balance to better understand and predict the effects of climate change. These findings have important implications for the future of glacier retreat and water reserves of the Jhelum basin.

Explaining the natural and anthropogenic factors driving glacier recession in Kashmir Himalaya, India

Glaciers across the Kashmir Himalayan region are melting at an accelerated pace compared to other regions across the Himalayan arc. This study analyzed the recession patterns of nine glaciers in the Kashmir Himalaya region over 28 years between 1992 and 2020 using satellite images and field measurements. The recession patterns were correlated with debris cover, topographic factors, and ambient black carbon (BC) concentration at glacier sites. HYSPLIT model was used to track the air mass sources at a 7-day time-step from September 1, 2014, to September 28, 2014, over the selected region. All nine glaciers revealed high recession as indicated by changes in the area (average recession: 20.8%) and snout position (~ 14 m a^-1). The relative percentage of debris on each glacier varied between ~ 0% (clean glacier) and 43%. Although the investigated glaciers lie in the same climatological regime, their topographical behavior is dissimilar with mean altitude ranging between 4000 and ~ 4700 m asl and the average slope varying from 17 to 24°. All the investigated glaciers are north-facing except G3 (southerly aspect). Our results indicate anomalously high ambient BC concentrations, ranging from 500 to 1364 ng m^-3, at the glacier sites, higher than previously studied for glaciers in the Himalayas and neighboring Tibetan Plateau. The backward air-mass trajectory modeling indicated both local and global sources of particulate matter in the study area. A comparative analysis of BC measurements and glacier recession with the studies conducted across high Asia indicated the influence of BC in accelerating the melting of glaciers in the Kashmir region.