Papers by Thupstan Angchuk
Increased up-glacier thinning in four major glaciers of High Mountain Asia revealed by geodetic mass balance estimates
Journal of Glaciology, May 18, 2020
We present the first-ever mass-balance (MB) observation (2014-19), reconstruction (between 1978 a... more We present the first-ever mass-balance (MB) observation (2014-19), reconstruction (between 1978 and 2019) and sensitivity of debris-free Stok glacier (33.98°N, 77.45°E), Ladakh Region, India. In-situ MB was negative throughout the study period except in 2018/19 when the glacier witnessed a balanced condition. For MB modelling, three periods were considered based on the available data. Period I (1978-87, 1988/89) witnessed a near balance condition (−0.03 ± 0.35 m w.e. a −1) with five positive MB years. Whereas Period II (1998-2002, 2003-09) and III (2011-19) experienced high (−0.9 ± 0.35 m w.e. a −1) and moderate (−0.46 ± 0.35 m w.e. a −1) negative MBs, respectively. Glacier area for these periods was derived from the Corona, Landsat and PlanetScope imageries using a semi-automatic approach. The in-situ and modelled MBs were in good agreement with RMSE of 0.23 m w.e. a −1 , R 2 = 0.92, P < 0.05. The average mass loss was moderate (−0.47 ± 0.35 m w.e. a −1) over 28 hydrological years between 1978 and 2019. Sensitivity analysis showed that the glacier was more sensitive to summer temperature (−0.32 m w.e. a −1°C−1) and winter precipitation (0.12 m w.e. a −1 for ± 10%). It was estimated that ∼27% increase in precipitation is required on Stok glacier to compensate for the mass loss due to 1°C rise in temperature.
Journal of Glaciology, Jun 23, 2020
The Himalayan glaciers contribute significantly to regional water resources. However, limited fie... more 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 Shigria benchmark glacier', shows a mass wastage which corresponds to the slowdown of the glacier in the past two decades.
Table S1. Radiative and turbulent heat fluxes in the High Mountain Asian (HMA) glacier/snow-cover... more Table S1. Radiative and turbulent heat fluxes in the High Mountain Asian (HMA) glacier/snow-covered/debris surfaces. All radiative fluxes are in W m-2. R net corresponds to the sum of S net and L net. Glacier/Snow-covered site Region Period of observation Lat (°) Long (°) Elevation (m) Surface type Reference Rnet (W m-2) H (W m-2) LE (W m-2) Tibetan Plateau (TP)
Journal of Earth System Science, Jul 28, 2021
This study presents a recent estimate (for year 2017) of ice thickness and volume of a small glac... more This study presents a recent estimate (for year 2017) of ice thickness and volume of a small glacier called Patsio Glacier located in Western Himalayas. Also, the present study aims to examine whether the improvement in GlabTop2 based estimates obtained for Chhota Shigri Glacier through the use of relatively accurate and high-resolution Digital Elevation Model (DEM) and glacier speciBc model parameterisation is consistent and can be extended to other glaciers. The version of GlabTop2 model used in this study is GlabTop2˙IITB (Glacier Bed Topography version 2˙Indian Institute of Technology Bombay). For validation purpose, ground penetrating radar (GPR) survey-based ice thickness estimates available at four cross-section proBles collected during July 2017 was used. Root mean square error (RMSE) of the modelled ice thickness estimates is about 14 m. Average and the maximum thickness of the modelled glacier ice is about 45 and 129 m, respectively. The obtained results when compared with an earlier study carried out using velocity-based approach indicate a significant improvement in the modelling accuracy. Moreover, a 16 percentage points reduction in uncertainty of the estimated ice thickness is seen when compared with a previous study involving different version of GlabTop2 model for Himalaya-Karakoram region. This is perhaps due to the use of a relatively accurate and high-resolution DEM and model parameterisation scheme adopted in this study, thus conBrming the consistency of the modelling approach for different glaciers. Based on the obtained ice thickness estimates, the modelled volume of the glacier stored ice was calculated to be 0.11198 ± 0.0162 km 3 in 2017.
Environmental Earth Sciences, Sep 1, 2016
Available published literatures on glacier mass loss and climate studies like temperature and pre... more Available published literatures on glacier mass loss and climate studies like temperature and precipitation are reviewed for Lahaul and Spiti region in northern India, which is a part of the western Himalayas. Chhota Shigri and Hamtah Glaciers are both located in the Lahaul and Spiti region and have the longest record of in situ glaciological mass balance (MB) measurements. We have compiled and compared all the dataset (different methods) related to glacier change with climate in the past few decades. Both the glaciers have experienced a significant mass loss during the study period. Different methods show diverse results for the glaciers studied for the same year; however, all results depicts overall unsteady state of both the glaciers. Data of Indian Meteorological Department (IMD) shows a significant increase in average temperature for the entire country and huge variability in precipitation particularly in the state of Himachal Pradesh. Temperature and precipitation are found to be the two main governing factors controlling the glacier health in this region. Thus, it can be said that the glaciers of Lahaul and Spiti region are losing mass due to changing weather conditions, especially the increasing air temperature. However, long-term MB and climate data will give a better insight into understand and predict the future scenario of glacier health in this region. Keywords Glacier mass balance Á Climate change Á Chhota Shigri Glacier Á Lahaul and Spiti region Á Western Himalayas This article is part of a Topical Collection in Environmental Earth Sciences on ''Water in Central Asia'', guest edited by Daniel Karthe,
Journal of climate change, Aug 6, 2018
The present meteorological study has been carried out on the Chhota Shigri glacier during the stu... more The present meteorological study has been carried out on the Chhota Shigri glacier during the study period from 1 October 2013 to 30 September 2014 (one hydrological year). The annual mean temperature over the surface of glacier was recorded to be-6.0 °C during the study period. This study shows that the hydrological year 2013/2014 was relatively colder as compared to the hydrological years 2009/10, 2010/11 and 2012/13 in the Chhota Shigri glacier. Maximum relative humidity (RH) in the study area was reported in the summer-monsoon season, whereas minimum relative humidity was observed in the post-monsoon season. On the other hand, highest mean seasonal incoming shortwave (SWI) radiation over the surface of Chhota Shigri glacier was found in the pre-monsoon season, whereas lowest SWI radiation was observed in the winter season. The annual mean incoming longwave (LWI) radiation and outgoing longwave (LWout) radiation in the investigation area were calculated to be 227 and 293 Wm-2 , respectively and the annual mean wind speed was computed to be 4.0 ms-1 during the hydrological year 2013/14. Wind regime of the study area plays a significant role in the transportation of moisture and melting of glacier. Wind rose diagram shows that wind blew from south to southwest direction during most of the time period at the Chhota Shigri glacier.
Applied Water Science, Oct 6, 2022
Identification of groundwater recharge zone is an important factor for water resource management ... more Identification of groundwater recharge zone is an important factor for water resource management in any area. The present study investigates the potential water recharge zones in the Sikkim state, a mountain region of the Eastern Himalayas. To identify potential watershed recharge zone in the region, a combination of geographic information system (GIS)-based weighted overlay index (WOI) tools and analytic hierarchy process (AHP) pairwise matrix techniques was applied. The delineated watershed recharge sites were classified into five different potential zones. The results show that the majority of the study area (54.22%) was under moderate recharge potential zone. Some of the suitable recharge potential sites are forest-covered regions; therefore, the construction of surface check dams could be a suitable recharge method; it will escalate the discharge in springs and also help to make them perineal. This study provides first-hand information on the groundwater recharge potential of East Sikkim, where the populace depends largely on spring water discharge. Also, it is useful in selecting areas for digging staggered contour trenches, pits, and other structures to recharge the spring water and improve the watershed management system.
Journal of Glaciology, Jun 16, 2021
Improving the knowledge on Himalayan glaciers mass balance is a key to understand the present and... more 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.
Surface energy balance and sublimation of the winter snow cover at 4863 m a.s.l. on Chhota Shigri Glacier moraine (western Himalaya, India) between 2009 and 2020
&amp;lt;p&amp;gt;Surface energy balance (SEB) is the most comprehensive way to explain th... more &amp;lt;p&amp;gt;Surface energy balance (SEB) is the most comprehensive way to explain the atmosphere-glacier interactions but requires extensive data. We analyse an 11-year (2009-2020) record of the meteorological dataset from an automatic weather station installed at 4863 m a.s.l., on a lateral moraine of the Chhota Shigri Glacier in the western Himalaya. The study was carried out over the winter months (December to April) to understand the SEB drivers and snow sublimation. Further, we examine 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 is the primary energy source. However, a significant amount of energy is dissipated by the turbulent heat fluxes. The cloud cover plays an important role in limiting the incoming short-wave radiation by up to 75%. It also restricts the turbulent heat fluxes by around 50%, consequently less snow sublimation. During the winter period, turbulent latent heat flux contributed the largest (63%) in the total SEB, followed by net all-wave radiation (29%) and sensible heat flux (8%). Dry air, along with the high snow surface temperature and wind speed, favours sublimation. We also observe that strong and cold winds, possibly through mid-latitude western disturbances, impede sublimation by bringing high moisture content in the region and cooling the snow surface. The estimated snow sublimation fraction is 18 to 42% of the total winter snowfall at the study site, indicating that the snow sublimation is an essential parameter in the surface mass balance and hydrological modelling at the high mountain Himalayan catchments.&amp;lt;/p&amp;gt;
Interrelationships among mass balance, meteorology, discharge, and surface velocity on Chhota Shigri Glacier over 2002-2019 using in-situ measurements
&amp;lt;p&amp;gt;Interrelationships among mass balance, meteorology, discharge, and surfa... more &amp;lt;p&amp;gt;Interrelationships among mass balance, meteorology, discharge, and surface velocity on Chhota Shigri Glacier over 2002-2019 using in-situ measurements&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Arindan MANDAL&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, AL. RAMANATHAN&amp;lt;sup&amp;gt;1*&amp;lt;/sup&amp;gt;, Mohd. Farooq AZAM&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;, Thupstan ANGCHUK&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, Mohd. SOHEB&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, Naveen KUMAR&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, Jose George POTTAKKAL&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;, Sarvagya VATSAL&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, Somdutta MISHRA&amp;lt;sup&amp;gt;1&amp;lt;/sup&amp;gt;, Virendra Bahadur SINGH&amp;lt;sup&amp;gt;1,4&amp;lt;/sup&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sup&amp;gt;&amp;amp;#160;&amp;lt;/sup&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;sup&amp;gt;*&amp;lt;/sup&amp;gt;Corresponding author email: alrjnu@gmail.com&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The Himalayan glaciers contribute significantly to regional water resources. However, limited field observations restrict our understanding of glacier dynamics and behavior. Here, we investigated the long-term in-situ mass balance, meteorology, ice velocity, and discharge of the Chhota Shigri Glacier over the past two decades. With 17 years of uninterrupted glacier-wide mass balance datasets, Chhota Shigri Glacier is one of the most studied glaciers in the Hindu-Kush Himalayan region in terms of mass balance record. The mean annual glacier-wide mass balance was negative, -0.46&amp;amp;#177;0.40 m w.e. a&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; during 2002-2019 corresponding to a cumulative wastage of about -8 m w.e. Mean winter mass balance was 1.15 m w.e. a&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; and summer mass balance was -1.35 m w.e. a&amp;lt;sup&amp;gt;-1 &amp;lt;/sup&amp;gt;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 &amp;amp;#8212; a benchmark &amp;amp;#8212; glacier, shows a mass wastage that corresponds to the glacier&amp;amp;#8217;s slowdown in the past two decades.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;
Determining fractures and their orientation for preventing in-situ seepage of water in the Poison Lake, Sikkim, India
Journal of Taibah University for Science, Dec 13, 2022
Geological Society, London, Special Publications, Sep 29, 2017
We describe a time series of meteorological parameters and surface energy balance components of a... more We describe a time series of meteorological parameters and surface energy balance components of a seasonal snow cover from an automatic weather station (4863 m a.s.l., 32.28°N, 77.58°E), for a winter season from 1 December 2012 to 30 March 2013, located on a moraine close to the equilibrium line altitude of Chhota Shigri glacier, Himachal Pradesh, India. The analysis shows that for over 80% of the time in winter, the snow surface was at a cooling phase. During late winter however, the surface had some positive residual energy which induced some melt during peak hours of the day. The net all-wave radiation was mostly negative during winter because of the high reflective property of snow and reduced incoming longwave radiation due to low cloud. The sensible heat flux heats the surface at night and enhances the cooling during day. The latent heat flux is always negative, showing that the surface is losing mass through sublimation processes (−0.83 mm w.e./day). A correlation between the energy fluxes and temperature shows a distinct relationship between fluxes. A comparison between the two studies performed on-and off-glacier reveals a significant difference in some parameters. A higher value (−1.08 mm/day) of sublimation rate at 4863 m a. s.l. shows that a large amount of energy available at the surface was used in sublimation processes. A comparatively lower albedo, relative humidity and net longwave radiation and higher latent heat flux, wind speed and net shortwave radiation yield a distinctive surface energy balance, highlighting the need for a large number of stations at different zones to achieve a coherent picture of energy balance in the region.
Analysis of surface energy balance (SEB) at the glacier surface is the most comprehensive way to ... more Analysis of surface energy balance (SEB) at the glacier surface is the most comprehensive way to explain the atmosphere-glacier interactions but that requires extensive data. In this study, we analyse an 11-year (2009-2020) record of the meteorological dataset from an automatic weather station installed at 4863 m a.s.l., on a lateral moraine of the Chhota Shigri Glacier in the western Himalaya. The study was carried out over the winter months (December to April) to understand SEB drivers and snow sublimation. Further, we examine 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 shortwave 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 shortwave radiation by 70%. It also restricts the turbulent heat fluxes by around 50%, consequently less snow sublimation. During the winter period, turbulent latent heat flux contributed the largest (63%) in the total SEB, followed by net all-wave radiation (29%) and sensible heat flux (8%). Sublimation rates were three times higher in clear-sky conditions than overcast, indicating a strong control of cloud cover in turbulent latent heat flux. Dry air, along with the high snow surface temperature and wind speed, favours sublimation. We also observed that strong and cold winds, possibly through mid-latitude western disturbances, impede sublimation by bringing high moisture content in 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 indicates snow sublimation is an essential parameter to be considered in the glaciohydrological modelling at the high mountain Himalayan catchments.
Annals of Glaciology, 2016
We present the updated glaciological mass balance (MB) of Chhota Shigri Glacier, the longest cont... more We present the updated glaciological mass balance (MB) of Chhota Shigri Glacier, the longest continuous annual MB record in the Hindu-Kush Karakoram Himalaya (HKH) region. Additionally, 4 years of seasonal MBs are presented and analyzed using the data acquired at an automatic weather station (AWS-M) installed in 2009 on a lateral moraine (4863 m a.s.l.). The glaciological MB series since 2002 is first recalculated using an updated glacier hypsometry and then validated against geodetic MB derived from satellite stereo-imagery between 2005 (SPOT5) and 2014 (Pléiades). Chhota Shigri Glacier lost mass between 2002 and 2014 with a cumulative glaciological MB of-6.72 m w.e. corresponding to a mean annual glacier-wide MB (B a) of-0.56 m w.e. a-1. Equilibriumline altitude (ELA 0) for the steady-state condition is calculated as �4950 m a.s.l., corresponding to an accumulation-area ratio (AAR 0) of �61%. Analysis of seasonal MBs between 2009 and 2013 with air temperature from AWS-M and precipitation from the nearest meteorological station at Bhuntar (1050 m a.s.l.) suggests that the summer monsoon is the key season driving the interannual variability of B a for this glacier. The intensity of summer snowfall events controls the B a evolution via controlling summer glacier-wide MB (B s).
Annual and seasonal mass balances of Chhota Shigri Glacier (benchmark glacier, Western Himalaya), India
EGUGA, Apr 1, 2015
ABSTRACT Several studies on Himalayan glaciers have been recently initiated as they are of partic... more ABSTRACT Several studies on Himalayan glaciers have been recently initiated as they are of particular interest in terms of future water supply, regional climate change and sea-level rise. In 2002, a long-term monitoring program was initiated on Chhota Shigri Glacier (15.68 km2, 9 km long, 5830-4050 m a.s.l.) located in Lahaul and Spiti Valley, Himachal Pradesh, India. This glacier lies in the monsoon–arid transition zone (western Himalaya) and is a representative glacier in Lahaul and Spiti Valley. We present here the updated glaciological mass balance (MB) of Chhota Shigri Glacier, the longest continuous annual mass balance record in the HKH region. Additionally, four years of seasonal mass balances are presented and analyzed using the data acquired at an automatic weather station (AWS) installed in 2009 on a lateral moraine (4863 m a.s.l.). Chhota Shigri Glacier lost mass between 2002 and 2014 with a cumulative glaciological MB of -6.75 m w.e. corresponding to a mean annual glacier-wide MB (Ba) of -0.56 m w.e. a-1. Ba were negative except for four years (2004/05, 2008/09, 2009/10 and 2010/11) when it was generally close to balanced conditions. The winter glacier-wide mass balance (Bw) between 2009 and 2013 ranges from a maximum value of 1.38 m w.e. in 2009/10 to a minimum value of 0.89 in 2012/13 year whereas the summer glacier-wide mass balance (Bs) varies from the highest value of –0.95 m w.e. in 2010/11 to the lowest value of –1.72 m w.e. in 2011/12 year. Equilibrium line altitude (ELA0) for steady state condition is calculated as ~4950 m a.s.l. corresponding to an accumulation area ratio (AAR0) of ~61%. An analysis of the seasonal MBs between 2009 and 2013 with air temperature from AWS and precipitation from the nearest meteorological station at Bhuntar (1050 m a.s.l.) suggests that the summer-monsoon is the key season driving Ba of this glacier. The intensity of summer snowfall events controls the Ba evolution via controlling Bs. The mean vertical mass balance gradient between 2002 and 2013 was 0.66 m w.e. (100 m)-1 quite similar to Alps, Nepalese Himalayas etc. Over debris covered area, the gradients are highly variable with a negative mean value of -2.15 m w.e. (100 m)-1 over 2002-2013 observation period. The negative gradients can be explained by the thickness of debris cover that increases with decrease in altitude, thus protecting the glacier more efficiently at lower altitudes. Mass balance is strongly dependent on debris cover, exposure and the shading effect of surrounding steep slopes.
Frontiers in sustainable food systems, Jan 10, 2023
The Indus is one of three largest river systems emerging from the Hindu-Kush Himalaya (HKH). In t... more The Indus is one of three largest river systems emerging from the Hindu-Kush Himalaya (HKH). In the Upper Indus Basin (UIB), water resources, agriculture and livelihoods are highly vulnerable to climate change induced hazards and risks. Present study investigates impacts of climate change on water availability, agriculture and livelihoods based on perception data collected through focus group discussions and key informant interviews from selected study sites in Gilgit-Baltistan and Leh-Ladakh subregions of the UIB. Findings revealed that climate change is inducing both direct and indirect impacts on water availability, agriculture, and livelihoods. Local people reported that changes in precipitations patterns, temperature and timing of seasons, and increased incidence of crop pest attacks are resulting in the decline of crop and livestock productivity (direct impacts). Climate change is also impacting productivity indirectly through degradation of rangelands/pastures and water variability in traditional irrigation systems. Local people are taking diverse adaptation measures to cope with climate change impacts. These measures include revival of less water intensive traditional crops, start of enterprises and value chain developments in Gilgit-Baltistan, and improvement in water management practices and integration of traditional agricultural products with tourism in Leh-Ladakh. Some adaptation measures are likely to have negative impacts on sustainability of local agriculture. For instance, inorganic agricultural practices in Gilgit-Baltistan, and unplanned shift to water intensive crops and improved breeds of livestock in both Gilgit-Baltistan and Leh-Ladakh. Based on findings, this study suggests establishing a learning mechanism for local communities through collaboration of local institutions from both sides of border and people to people connections.
Transportation of Suspended Sediment from Meltwater of the Patsio Glacier, Western Himalaya, India
Proceedings of the National Academy of Sciences, India. Section A, Physical sciences, Feb 3, 2015
ABSTRACT Discharge and transportation of suspended sediment from the Patsio glacier have been stu... more ABSTRACT Discharge and transportation of suspended sediment from the Patsio glacier have been studied for 2 years. During the study period 2011 and 2012, daily mean discharge was measured to be 0.70 and 0.94 m(3)/s, respectively. Daily mean suspended sediment concentration during the study period 2011 and 2012 was found to be 28.1 and 48.8 mg l(-1), respectively. Whereas, daily mean suspended sediment load during the study period was estimated to be 1.70 and 3.96 t day(-1). Suspended sediment concentrations generally follow the discharge pattern of the glacier for both years. High average TDS/TSM ratio of the Patsio glacier meltwater for both years shows the dominancy of chemical weathering over the physical weathering. The physical weathering rate of the study area during year 2011 and 2012 was estimated to be 79.3 and 185 t km(-2) year(-1), respectively. The chemical (cation) weathering rate of the Patsio glacier is much higher than other Himalayan glaciers, which may be due to high intensity of chemical weathering in this glacier.
13 years (2002-2015) of in-situ mass balance record and meteorological conditions of Chhota Shigri Glacier, Indian Himalaya
AGU Fall Meeting Abstracts, Dec 1, 2016
Journal of Earth Science & Climatic Change, 2014
Available published literatures on glacier mass balance and climate studies i.e. temperature chan... more Available published literatures on glacier mass balance and climate studies i.e. temperature change, precipitation variation etc. are reviewed for whole Lahaul-Spiti region as well as for western Himalaya. Chhota Shigri and Hamta glaciers both lie in the Lahaul-Spiti region and have the longest in-situ datasets till the date ~10 years, surface mass balance data, geodetic, remotely sensed mass balance data are available. We have compiled and compared all the datasets (different methods) and tried to link up the glacier mass balance with the climate of the past few decades. In the past decade both the glaciers have experienced negative mass balance. However, all the values of mass balance for same years are not corresponding with different methods, but it is clear that the two glaciers are losing mass and behaving like other glaciers with time. Data from Indian Meteorological Department shows a significant increase of average temperature for the entire country and huge variability in precipitation of Himachal Pradesh. Temperature and precipitation are the two main governing factors of the glacier health. It has been observed and predicted that glaciers of the Lahual-Spiti region are losing mass due to change in weather pattern, especially increasing air temperature which is the key parameter of glacier change. However, long-term mass balance and climate data are essential for the better understanding and to predict the future status of glaciers in Lahaul-Spiti region.
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Papers by Thupstan Angchuk