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Improving the knowledge on Himalayan glaciers mass balance is a key to understand the present and past annual atmospheric variations and future water availability in the region. Here, we present glaciological mass balance for Patsio Glacier, located in Himachal Pradesh (India), western Himalaya. Annual glacier-wide mass balance was measured for 7 consecutive years (2010/11 to 2016/17) and winter mass balance for 6 years (2011/12 to 2016/17). The cumulative mass balance over this period was −2.35 ± 0.37 m w.e. The corresponding mean mass balance was −0.34 m w.e. a−1. The mean annual ablation gradient excluding the debris-covered area was 0.47 m w.e. (100 m)−1. The annual ablation over the debris-covered area is reduced by an average of −1.0 m w.e. compared to the clean ice surface. Winter mass balance was consistently positive with a maximum of 1.34 m w.e. in 2014/15 and a minimum of 0.88 m w.e. in 2011/12. Multiple regression analysis between annual mass balance versus annual and winter precipitation of the Lahaul-Spiti region shows a significant positive correlation. Our results highlight the importance of monitoring seasonal mass balance and consideration of non-climatic parameters (debris and aspect) while estimating the glacier-wide mass balance. [ABSTRACT FROM AUTHOR]

The Himalayan glaciers contribute significantly to regional water resources. However, limited field observations restrict our understanding of glacier dynamics and behaviour. Here, we investigated the long-term in situ mass balance, meteorology, ice velocity and discharge of the Chhota Shigri Glacier. The mean annual glacier-wide mass balance was negative, −0.46 ± 0.40 m w.e. a−1 for the period 2002–2019 corresponding to a cumulative wastage of −7.87 m w.e. Winter mass balance was 1.15 m w.e. a−1 and summer mass balance was −1.35 m w.e. a−1 over 2009–2019. Surface ice velocity has decreased on average by 25–42% in the lower and middle ablation zone (below 4700 m a.s.l.) since 2003; however, no substantial change was observed at higher altitudes. The decrease in velocity suggests that the glacier is adjusting its flow in response to negative mass balance. The summer discharge begins to rise from May and peaks in July, with a contribution of 43%, followed by 38% and 19% in August and September, respectively. The discharge pattern closely follows the air temperature. The long-term observation on the 'Chhota Shigri – a benchmark glacier', shows a mass wastage which corresponds to the slowdown of the glacier in the past two decades. [ABSTRACT FROM AUTHOR]

This study presents a reconstruction of the mass balance (MB) of Chhota Shigri glacier, Western Himalaya, India, and discusses the regional climatic drivers responsible for its evolution since 1969. The MB is reconstructed by a temperature-index and an accumulation model using daily airtemperature and precipitation records from the nearest meteorological station, at Bhuntar Observatory. The only adjusted parameter is the altitudinal precipitation gradient. The model is calibrated against 10 years of annual altitudinal MB measurements between 2002 and 2012 and decadal cumulative MBs between 1988 and 2010. Three periods were distinguished in the MB series. Periods I (1969-85) and III (2001-12) show significant mass loss at MB rates of -0.36±0.36 and -0.57±0.36mw.e. a-1 respectively, whereas period II (1986-2000) exhibits steady-state conditions with average MBs of -0.01±0.36mw.e. a-1. The comparison among these three periods suggests that winter precipitation and summer temperature are almost equally important drivers controlling the MB pattern of Chhota Shigri glacier at decadal scale. The sensitivity of the modelled glacier-wide MB to temperature is -0.52mw.e. a-1 8C-1 whereas the sensitivity to precipitation is calculated as 0.16mw.e. a-1 for a 10% change. [ABSTRACT FROM AUTHOR]

The article discusses a research study on Chhota Shigri glacier in western Himalaya, India as to the shift in its dynamic behaviour and mass-balance. The article analyzed data on measurements of Chhota Shigri glacier mass-balance between 1987 and 1989 as well as the survey of surface ice velocity and bedrock topography in the same period through stake displacement and gravimetric methods. The measurements of annual surface mass-balance (SMB) between 2002 and 2010 were done through direct glaciological method. Conclusions indicated the negative mass balance experienced by Chhota Shigri glacier during the 2002-10 period while elevation in the ablation area and ice velocities have decreased since 2003.

Glacier-wide mass balances and runoffs are reconstructed over 1969-2016 for Chhota Shigri Glacier catchment (India) applying a glacio-hydrological model. The model is forced using in-situ daily air-temperature and precipitation records from the meteorological stations at Bhuntar city (1092 m a.s.l.), glacier base camp (3850 m a.s.l.) and glacier side moraine (4863 m a.s.l.). The modelled mean annual mass balance is −0.30±0.36 m w.e. a-1 (meter water equivalent year-1), while the mean catchment-wide runoff is 1.56±0.23 m w.e. a-1 over 1969-2016. Three periods are distinguished in the reconstructed mass balance and runoff series. Periods I (1969−1985) and III (2001−2016) show glacier mass wastage at rates of −0.36 and −0.50 m w.e. a−1, respectively, corresponding to catchment-wide runoffs of 1.51 and 1.65 m w.e. a-1, respectively. Conversely, period II (1986−2000) exhibits steady-state conditions with average mass balances of −0.01 m w.e. a−1, and corresponding runoff of 1.52 m w.e. a-1. The reduced ice melt (0.20 m w.e. a-1) over period II, in agreement with steady-state conditions, is compensated by the increased snow melt (1.03 m w.e. a-1), providing almost similar catchment-wide runoffs for period I and II. The increased runoff after 2000 is mainly governed by increased ice melt (0.32 m w.e. a-1) over period III. Snow accumulation in winter and summer seasons together control the glacier-wide mass balances as well as catchment-wide runoff. Snow melt contributes the maximum to the total mean annual runoff with 63% share while glacier melt and rain contribute 17% and 20% respectively over the whole period. [ABSTRACT FROM AUTHOR]