Glacier area change (1993–2019) and its relationship to debris cover, proglacial lakes, and morphological parameters in the Chandra-Bhaga Basin, Western Himalaya, India

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Annual and seasonal glaciological mass balance of Patsio Glacier, western Himalaya (India) from 2010 to 2017

The authors are highly thankful for our ex-glacier group members, Dr Parmanand Sharma, Dr Anurag Linda and Dr Jose George Pottakkal for helping in initiating and conducting mass-balance measurements at the beginning of the study period. We are highly grateful to the Scientific Editor Argha Banerjee and the two anonymous referees whose detailed comments and suggestions have significantly improved the paper. TA is grateful to Jawaharlal Nehru University, for the laboratory facilities throughout the study period. The authors are grateful for various glacier training programmes conducted by DST, GOI, and also for CHARIS project. We are also thankful to all the field experts and assistants, especially Mr Adikari, who helped in conducting the fieldwork. Finally, we thank the USGS for Landsat and SRTM data, Planet Labs for PlanetScope image and Indian Meteorological Department for precipitation data.Peer reviewe

Modelling 60 years of glacier mass balance and runoff for Chhota Shigri Glacier, Western Himalaya, Northern India

Glacier mass balance and runoff are simulated from 1955 to 2014 for the catchment (46% glacier cover) containing Chhota Shigri Glacier (Western Himalaya) using gridded data from three regional climate models: (1) the Rossby Centre regional atmospheric climate model v.4 (RCA4); (2) the REgional atmosphere MOdel (REMO); and (3) the Weather Research and Forecasting Model (WRF). The input data are downscaled to the simulation grid (300 m) and calibrated with point measurements of temperature and precipitation. Additional input is daily potential global radiation calculated using a DEM at a resolution of 30 m. The mass-balance model calculates daily snow accumulation, melt and runoff. The model parameters are calibrated with available mass-balance measurements and results are validated with geodetic measurements, other mass-balance model results and run-off measurements. Simulated annual mass balances slightly decreased from −0.3 m w.e. a−1 (1955–99) to −0.6 m w.e. a−1 for 2000–14. For the same periods, mean runoff increased from 2.0 m3 s−1 (1955–99) to 2.4 m3 s−1 (2000–14) with glacier melt contributing about one-third to the runoff. Monthly runoff increases are greatest in July, due to both increased snow and glacier melt, whereas slightly decreased snowmelt in August and September was more than compensated by increased glacier melt

An 11-year record of wintertime snow-surface energy balance and sublimation at 4863 m a.s.l. on the Chhota Shigri Glacier moraine (western Himalaya, India)

International audienceAnalysis of surface energy balance (SEB) at the glacier/snow surface is the most comprehensive way to explain the atmosphere-glacier/snow interactions, but that requires extensive data. In this study, we have analysed an 11-year (2009-2020) record of the meteorological dataset from an automatic weather station installed at 4863 ma.s.l. (above sea level) on a lateral moraine of the Chhota Shigri Glacier, western Himalaya. The study was carried out over the winter months (December to April) to understand SEB drivers and snow loses through sublimation. Furthermore, this study examines the role of cloud cover on SEB and turbulent heat fluxes. The turbulent heat fluxes were calculated using the bulk-aerodynamic method, including stability corrections. The net short-wave radiation was the primary energy source. However, the turbulent heat fluxes dissipated a significant amount of energy. The cloud cover plays an important role in limiting the incoming short-wave radiation by about 70 %. It also restricts the turbulent heat fluxes by more than 60 %, resulting in lower snow sublimation. During winter, turbulent latent heat flux contributed the largest proportion (64 %) in the total SEB, followed by net radiation (25 %) and sensible heat flux (11 %). Sublimation rates were 3 times higher in clear-sky than overcast conditions, indicating a strong role of cloud cover in shaping favourable conditions for turbulent latent heat flux by modulating the near-surface boundary layer conditions. Dry air, along with high snow-surface temperature and wind speed, favours sublimation. Besides, we also observed that strong and cold winds, possibly through mid-latitude western disturbances, impede sublimation by bringing high moisture content to the region and cooling the snow surface. The estimated snow sublimation fraction was 16 %-42 % of the total winter snowfall at the study site. This study substantiates that the snow sublimation is an essential variable to be considered in glaciohydrological modelling at the high-mountain Himalayan glacierised catchments

Challenges in understanding the variability of the cryosphere in the Himalaya and its impact on regional water resources

Authors are grateful to UKIERI and DST for supporting us financially through UKIERI-DST Partnership Development Workshops. RR would like to thank the funding agency Ministry of Earth Science (MoES), Government of India for the project titled Estimating Mass balance of glaciers in the Bhaga Basin, Western Himalaya using GPR and Remote Sensing methods (Grant Ref. No: MoES/PAMC/H&C/107/2018-PC-II dated 27.07.2019).The Himalaya plays a vital role in regulating the freshwater availability for nearly a billion people living in the Indus, Ganga, and Brahmaputra River basins. Due to climate change and constantly evolving human-hydrosphere interactions, including land use/cover changes, groundwater extraction, reservoir or dam construction, water availability has undergone significant change, and is expected to change further in the future. Therefore, understanding the spatiotemporal evolution of the hydrological cycle over the Himalaya and its river basins has been one of the most critical exercises toward ensuring regional water security. However, due to the lack of extensive in-situ measurements, complex hydro-climatic environment, and limited collaborative efforts, large gaps in our understanding exist. Moreover, there are several significant issues with available studies, such as lack of consistent hydro-meteorological datasets, very few attempts at integrating different data types, limited spatiotemporal sampling of hydro-meteorological measurements, lack of open access to in-situ datasets, poorly accounted anthropogenic climate feedbacks, and limited understanding of the hydro-meteorological drivers over the region. These factors result in large uncertainties in our estimates of current and future water availability over the Himalaya, which constraints the development of sustainable water management strategies for its river catchments hampering our preparedness for the current and future changes in hydro-climate. To address these issues, a partnership development workshop entitled “Water sEcurity assessment in rIvers oriGinating from Himalaya (WEIGH),” was conducted between the 07th and 11th September 2020. Based on the intense discussions and deliberations among the participants, the most important and urgent research questions were identified. This white paper synthesizes the current understanding, highlights, and the most significant research gaps and research priorities for studying water availability in the Himalaya.Publisher PDFPeer reviewe