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

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.

Glacio-metrological measurements of Patsio glacier, Himachal Pradesh (India), Western Himalaya

<p><span>We present the glacio-metrological measurements on the Patsio glacier, located in the Lahaul-Spiti region, Himachal Pradesh, western Himalaya. In-situ annual and seasonal mass balance measurements have been monitored since 2010 and 2012 respectively. Subsequently, an automatic weather station was installed in the summer of 2015. The baseline investigations show a large variability in meteorological conditions during different seasons. Summer was warm and calm, whereas winter is cold and windy with high precipitation, especially snow. Peak ablation months were July and August. Mean annual temperature over the study period was low (-6.3 °C). January recorded as the coldest month and July as hottest corresponding to a mean of -16.8 and 4.28 °C, respectively. Two contrasting wind flow over the Patsio glacier valley was prominent. The persistent katabatic flow was observed during the winter season and up-valley wind in summer. A classic Temperature Index Model was used to estimate the melt from the Patsio glacier, for the years 2016 and 2017. Degree-day factor (DDF) for various components (snow, ice, and debris covered ice) was estimated using field data. High DDFs for snow, ice, and debris-covered ice were observed compared to other studies. The simulated results (snow and ice) were in good agreement with observed data (R2 = 0.88 in 2016 and 0.93 in 2017). Temperature is the main governing factor in inducing the melt. This study gives insight the metrological conditions together with snow and ice melt of Patsio glacier situated in the high and dry region of the Himalaya.</span></p>

A new species of Oxytropis (Fabaceae: Papilionoideae) from India

A new species Oxytropis sanjappae is described and illustrated from the Himalaya in India. The new species is widely scattered from Losar to Kaza in Lahul-Spiti region of Himachal Pradesh State. The relationship of the species has been discussed with O. cachemiriana and O. tatarica. The new species differs in having hairs very dense, silky and white, stems generally absent or quite reduced, racemes capitate, globose-ovoid or oblong, many-flowered, dense and elongating in infruitescence, calyx teeth distinctly longer than tube, corolla light purplish pink and almost equal to calyx, wing petals obtuse at apex, mucro of the keel petal ca. 1 mm long and pods comparatively larger in size. A taxonomic key to the all 18 species of the genus occurring in India including new ones has been provided for the first time. In addition, the ecological studies related with the frequency, density, basal cover and importance value index (IVI) have also been carried out to know the conservation status of the species in the Himalaya.

Balanced conditions or slight mass gain of glaciers in the Lahaul and Spiti region (northern India, Himalaya) during the nineties preceded recent mass loss

The volume change of the Chhota Shigri Glacier (India, 32° 20 N, 77° 30' E) between 1988 and 2010 has been determined using in situ geodetic measurements. This glacier has experienced only a slight mass loss between 1988 and 2010 (−3.8 ± 2.0 m w.e. (water equivalent) corresponding to −0.17 ± 0.09 m w.e. yr−1). Using satellite digital elevation models (DEM) differencing and field measurements, we measure a negative mass balance (MB) between 1999 and 2010 (−4.8 ± 1.8 m w.e. corresponding to −0.44 ± 0.16 m w.e. yr−1). Thus, we deduce a slightly positive or near-zero MB between 1988 and 1999 (+1.0 ± 2.7 m w.e. corresponding to +0.09 ± 0.24 m w.e. yr−1). Furthermore, satellite DEM differencing reveals that the MB of the Chhota Shigri Glacier (−0.39 ± 0.15 m w.e. yr−1) has been only slightly less negative than the MB of a 2110 km2 glaciarized area in the Lahaul and Spiti region (−0.44 ± 0.09 m w.e. yr−1) during 1999−2011. Hence, we conclude that the ice wastage is probably moderate in this region over the last 22 yr, with near equilibrium conditions during the nineties, and an ice mass loss after. The turning point from balanced to negative mass budget is not known but lies probably in the late nineties and at the latest in 1999. This positive or near-zero MB for Chhota Shigri Glacier (and probably for the surrounding glaciers of the Lahaul and Spiti region) during at least part of the 1990s contrasts with a recent compilation of MB data in the Himalayan range that indicated ice wastage since 1975. However, in agreement with this compilation, we confirm more negative balances since the beginning of the 21st century.