Chhota Shigri Research Articles

Meltwater runoff in a changing climate (1951–2099) at Chhota Shigri Glacier, Western Himalaya, Northern India

ABSTRACTMeltwater runoff in the catchment area containing Chhota Shigri glacier (Western Himalaya) is simulated for the period 1951–2099. The applied mass-balance model is forced by downscaled products from four regional climate models with different horizontal resolution. For the future climate scenarios we use high resolution time series of 5 km grid spacing, generated using the newly developed Intermediate Complexity Atmospheric Research Model. The meteorological input is downscaled to 300 m horizontal resolution. The use of an ice flow model provides annually updated glacier area for the mass-balance calculations. The mass-balance model calculates daily snow accumulation, melt, runoff, as well as the individual runoff components (glacial melt, snowmelt and rain). The resulting glacier area decreases by 35% (representative concentration pathway (RCP) 4.5 scenario) to 70% (RCP 8.5 scenario) by 2099 relative to 2000. The average annual mass balance over the whole model period (1951–2099) was –0.4 (±0.3) m w.e. a–1. Average annual runoff does not differ substantially between the two climate scenarios. However, for the years after 2040 our results show a shift towards earlier snowmelt onset that increases runoff in May and June, and reduced glacier melt that decreases runoff in August and September. This shift is much stronger pronounced in the RCP 8.5 scenario.

Numerical modelling of past retreat and future evolution of Chhota Shigri glacier in Western Indian Himalaya

ABSTRACT The history of glacier length fluctuations serves as a reliable indicator of the past climate. In this paper, a numerical flowline model has been used to study the relationship between length variations of Chhota Shigri glacier and local climate since 1876. The simulated front positions of Chhota Shigri glacier are in agreement with those observed. After a successful simulation of the past retreat, the model was also used to predict future evolution of the glacier for the next 100 years under different climatic scenarios. These simulations indicate that the Chhota Shigri glacier may lose ~90% of its present volume by 2100 if the local temperature increases by 2.4 K, and for a temperature rise of 5.5 K, the glacier loses almost all its volume.

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

ABSTRACTGlacier 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.

Hydrogeochemistry of the Chhota Shigri glacier meltwater, Chandra basin, Himachal Pradesh, India: solute acquisition processes, dissolved load and chemical weathering rates

The chemical compositions of various ions in meltwater of the Chhota Shigri glacier were analysed during the observation period from May to October 2010. Total 164 samples of meltwater were collected in two times a day at 8.0 a.m and 6.0 p.m. Bicarbonate and calcium were the dominant anion and cation in meltwater of the investigation area. High ratios of (Ca + Mg) versus TZ+ and (Ca + Mg) versus (Na + K) demonstrate that hydrogeochemistry of the study area was mainly governed by carbonate type weathering. The average sulphate mass fraction of meltwater was computed to be 0.31 ± 0.12, showing dominancy of bicarbonate over sulphate. This excess bicarbonate would be generated by an alternative proton supply mechanism due to biological activities in the bed rock lithology and sulphide oxidation may be about the same as carbonation as a driver of chemical weathering at Chhota Shigri glacier. In general, major ions and total dissolved solid concentrations showed decreasing trend with increasing discharge from the study area. The average daily mean dissolved load of this glacier was much lower than that of the Gangotri glacier, which may be due to low meltwater runoff and lithology of the investigation area. The cation weathering rates of study area for early, peak and late melt seasons were computed to be 694, 1631 and 481 meq m−2 a−1, respectively. The average value of chemical denudation rates of the Chhota Shigri glacier meltwater was found lower than that of the Dokriani glacier.

Comparative Assessment of Volume Change in Kolahoi and Chhota Shigri Glaciers, Western Himalayas, Using Empirical Techniques

Comparative Assessment of Volume Change in Kolahoi and Chhota Shigri Glaciers, Western Himalayas, Using Empirical Techniques

Assessing the status of glaciers in part of the Chandra basin, Himachal Himalaya: A multiparametric approach

This study investigates the change in multiple glacier parameters of three valley-type glaciers (Sakchum (SC), Chhota Shigri (CS), and Bara Shigri (BS)) located in Chandra basin, Himachal Himalaya, sharing the same climatic regime, and assesses the control of nonclimatic factors on wholesome glacier response. Multitemporal satellite remote sensing data from Landsat-TM/ETM/OLI (1993–2014), and Terra-ASTER (2002–2014) along with an SRTM digital elevation model were used for extraction of the glacier parameters. Results show that while SC and BS retreated (SC: 10.65±2.52m/y; BS: 15.51±2.52m/y) and lost area (SC: 0.49±0.0032km2, BS: 1.18±0.0032km2), the CS remained relatively stable (retreat rate: 4.06±2.52m/y, area loss: 0.19±0.0032km2) during 1993–2014. However, results of surface ice velocities (SIV) change (SC: 24.41%, CS: 21.60%, and BS: 28.49%) and surface elevation change (SC: −1.22m/y, CS: −0.91m/y and BS: −1.21m/y) suggest a comparable slowing down and surface lowering from 2002 to 2014. Debris cover also varied substantially (SC: 30.25%, CS: 11.96%, BS: 19.61%) on these glaciers. Results reveal that higher retreat/deglaciation of glaciers was associated with higher altitudinal range, slow SIV in lower ablation zones (LAZ), and glacier hypsometry. Debris cover on glaciers was found to be controlled by slope, higher deglaciation rates, higher SIV in the upper ablation zone (UAZ) coupled with lower SIV in LAZ and surface lowering. Glacier SIV was primarily governed by slope gradient, differential surface lowering, and size of accumulation zone (ACZ). The SIV results confirm the presence of stagnant zones in the lower ablations of SC (<1km upstream) and BS (<6km upstream) and a major SIV dropdown in the UAZ (SC: 34.48%, BS: 37.35%), indicating the expansion of stagnant zones farther up. Glacier surface lowering seemed to be influenced by ice-flux, changing spatial distribution of debris cover, presence of supraglacial lakes, and ice cliffs bordering them. Melting around supraglacial lakes and backwasting of ice cliffs may be the prime reasons behind intense mass loss observed in the stagnant zone of the Bara Shigri glacier, where surface lowering was ~32% higher than glacier-wide thinning. Differential surface lowering in glaciers reduced the surface gradient and hence the SIV. Also, rapid surface gradient changes and SIV dropdown in the Sakchum glacier indicate possible development of supraglacial lakes on it in the future. Interestingly, despite close proximity, SC, CS, and BS demonstrate three distinct ablation patterns, reemphasizing the role of nonclimatic factors. Overall, the study states that mutual variation of glacier parameters together with nonclimatic factors exercise a great control on glacier response.

Unsteady state of glaciers (Chhota Shigri and Hamtah) and climate in Lahaul and Spiti region, western Himalayas: a review of recent mass loss

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.

Identification of Potential Glacial Lake Sites and Mapping Maximum Extent of Existing Glacier Lakes in Drang Drung and Samudra Tapu Glaciers, Indian Himalaya

The Himalayan glaciers feed major Asian river systems sustaining the lives of more than 800 million people. Though the rates of retreat of individual glaciers are uncertain, on the whole the Himalayan glaciers have been losing mass at an increasing rate over the past few decades. With the changing climate, glaciers will continue to shrink and the rates of retreat may increase even further. This may lead to the formation of moraine dammed glacial lakes, which can cause outburst floods upon failure of the dam, catastrophic to human life and infrastructure downstream. Therefore, identification of potential lake sites and predicting the expansion of existing lakes are crucial for timely monitoring and mitigation of these hazards. In the present study, glacier surface velocity and slope are used to calculate ice thickness, by applying a basic parallel flow model, subsequently outlining the bed topography and locating potential lake sites in over-deepenings in the bedrock. Comparison of the modelled and measured ice thickness values on Chhota Shigri glacier suggests a model uncertainty of +/- 15%. The model is further applied to Samudra Tapu and Drang Drung glaciers using satellite data between the years 1999 and 2001, where eight potential lake sites were identified with mean depths varying between 33 +/- 5 and 93 +/- 14 m, of which three sites have a volume greater than 0.01 km(3). The analysis predicts an over-deepening near the snout of Samudra Tapu, in close proximity to an existing moraine dammed lake. A portion of the predicted site has already evolved into a lake between the years 2000 and 2015, which upon further deglaciation could lead to an expansion of the existing lake by an area of 14 +/- 2 ha. This observation further validates the model prediction of lake expansion. The present study demonstrates the utility of the model to predict maximum expansion of the existing lakes and possible formation of new lakes due to glacier retreat. Systematic application of this technique can provide information crucial to policy makers and planners dealing with the security of people living in the mountains.

Regional representation of glaciers in Chandra Basin region, western Himalaya, India

Hamtah and Chhota Shigri are two nearby, well monitored glaciers of western Himalaya, lying in the same climatic zone and driven by the same climatic conditions. In this study, topographical characteristics of both the glacier have been explored to understand the role of topography in controlling the glacier response. Further, their topographical characteristics and possible response towards climatic variations have been compared with each other and also with that of the other glaciers in the basin to find out the suitability of these two glaciers to be considered as representative of the region. Multi sensor and multi temporal remote sensing data have been used to carry out to fulfill the objectives. It is found that being in the same climatic zone, the mean accumulation area ratio of Chhota Shigri is 54% and Hamtah is 11% between 1980 and 2014. In comparison to Hamtah, Chhota Shigri glacier has a small upslope area, low compactness ratio indicating the ability of the glacier to receive direct precipitation and solar radiation. The analysis revealed that the Chhota Shigri glacier has a closer resemblance with the other glaciers in the region than Hamtah glacier. Also, the topographical settings of Chhota Shigri glacier are suitable for recording and reflecting year-to-year climatic variations.

Glacial runoff and transport of suspended sediment from the Chhota Shigri glacier, Western Himalaya, India

Glacial runoff and suspended sediment transport characteristics of the Chhota Shigri glacier were studied during the whole ablation period (May–October 2010). Discharge patterns of this glacier show that August experiences maximum runoff accounting for 34.2 % of the total runoff, followed by July 32.9 %, June 14.3 %, September 12.5 %, May 5.2 % and October 0.9 %. During the study period, the maximum runoff (Qmax) was observed in the evening (4–6 p.m.), whereas minimum runoff (Qmin) was observed in the morning (7–9 a.m.). The lag time between generation of meltwater from the glacier and its emergence as runoff varied from 1 to 4 h depending on the condition of melting during the melt season. A good correlation (r2 = 0.71) was found between daily mean glacier-specific runoff and air temperature of the study area. Daily mean concentrations of suspended sediment for May, June, July, August, September and October were found as 155, 506, 577, 591, 80.9 and 30.8 mg l−1, respectively, showing maximum concentration of suspended sediment in August, followed by July. Suspended sediment load also follows a similar trend. Diurnal variations in the concentration of suspended sediment of the investigation area are directly associated with diurnal variations in meltwater runoff. There is a strong relationship between concentration of suspended sediment and discharge (r2 = 0.79) and suspended sediment load with discharge (r2 = 0.94). The average sediment yield of the Chhota Shigri glacier basin was computed as 1689 t km−2 year−1 during the melt season, much higher than the worldwide and Indian averages.

Meteorological conditions, seasonal and annual mass balances of Chhota Shigri Glacier, western Himalaya, India

AbstractWe 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 (4863ma.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 –6.72mw.e. corresponding to a mean annual glacier-wide MB (Ba) of –0.56mw.e. a–1. Equilibrium-line altitude (ELA0) for the steady-state condition is calculated as ~4950ma.s.l., corresponding to an accumulation–area ratio (AAR0) 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 (1050ma.s.l.) suggests that the summer monsoon is the key season driving the interannual variability of Ba for this glacier. The intensity of summer snowfall events controls the Ba evolution via controlling summer glacier-wide MB (Bs).

Seasonal changes in surface albedo of Himalayan glaciers from MODIS data and links with the annual mass balance

Abstract. Few glaciological field data are available on glaciers in the Hindu Kush–Karakoram–Himalayan (HKH) region, and remote sensing data are thus critical for glacier studies in this region. The main objectives of this study are to document, using satellite images, the seasonal changes of surface albedo for two Himalayan glaciers, Chhota Shigri Glacier (Himachal Pradesh, India) and Mera Glacier (Everest region, Nepal), and to reconstruct the annual mass balance of these glaciers based on the albedo data. Albedo is retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) images, and evaluated using ground based measurements. At both sites, we find high coefficients of determination between annual minimum albedo averaged over the glacier (AMAAG) and glacier-wide annual mass balance (Ba) measured with the glaciological method (R2 = 0.75). At Chhota Shigri Glacier, the relation between AMAAG found at the end of the ablation season and Ba suggests that AMAAG can be used as a proxy for the maximum snow line altitude or equilibrium line altitude (ELA) on winter-accumulation-type glaciers in the Himalayas. However, for the summer-accumulation-type Mera Glacier, our approach relied on the hypothesis that ELA information is preserved during the monsoon. At Mera Glacier, cloud obscuration and snow accumulation limits the detection of albedo during the monsoon, but snow redistribution and sublimation in the post-monsoon period allows for the calculation of AMAAG. Reconstructed Ba at Chhota Shigri Glacier agrees with mass balances previously reconstructed using a positive degree-day method. Reconstructed Ba at Mera Glacier is affected by heavy cloud cover during the monsoon, which systematically limited our ability to observe AMAAG at the end of the melting period. In addition, the relation between AMAAG and Ba is constrained over a shorter time period for Mera Glacier (6 years) than for Chhota Shigri Glacier (11 years). Thus the mass balance reconstruction is less robust for Mera Glacier than for Chhota Shigri Glacier. However our method shows promising results and may be used to reconstruct the annual mass balance of glaciers with contrasted seasonal cycles in the western part of the HKH mountain range since the early 2000s when MODIS images became available.

Comparison of energy balance on Gangotri and Chhota Shigri Glaciers

Abstract. Surface energy balance of a glacier governs the physical processes taking place at the surface-atmosphere interface and connects ice ablation/accumulation to climate variability. To understand the response of Himalayan glaciers to climatic variability, a study was taken to formulate energy balance equation on two of the Indian Himalayan glaciers, one each from Indus and Ganga basins, which have different climatic and physiographic conditions. Study was carried out over Gangotri glacier (Ganga basin) and Chhota Shigri(CS) glacier from Chandra sub-basin (Indus basin). Gangotri glacier is one of the largest glaciers in the central Himalaya located in Uttarkashi District, Uttarakhand, India. Chhota Shigri glacier of Chandra sub-basin lies in Lahaul and Spiti valley of Himachal Pradesh. Energy balance components have been computed using inputs derived from satellite data, AWS (Automatic Weather Station) data and field measurements. Different components of energy balance computed are net radiation (includes net shortwave and net longwave radiation), sensible heat flux and latent heat flux. In this study comparison has been made for each of the above energy balance components as well as total energy for the above glaciers for the months of November and December, 2011. It is observed that net radiation in Gangotri glacier is higher by approximately 43 % in comparison to Chhota Shigri glacier; Sensible heat flux is lesser by 77 %; Latent heat flux is higher by 66 % in the month of November 2011. Comparison in the month of December shows that net radiation in Gangotri glacier is higher by approximately 22 % from Chhota Shigri glacier; Sensible heat flux is lesser by 90 %; Latent heat flux is higher by 3 %.Total energy received at the glacier surface and contributes for melting is estimated to be around 32 % higher in Gangotri than Chhota Shigri glacier in November, 2011 and 1.25 % higher in December, 2011. The overall results contribute towards higher melting rate in November and December, 2011 in Gangotri than Chhota Shigri glacier.

Processes governing the mass balance of Chhota Shigri Glacier (western Himalaya, India) assessed by point-scale surface energy balance measurements

Abstract. Some recent studies revealed that Himalayan glaciers were shrinking at an accelerated rate since the beginning of the 21st century. However, the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July to October 2013) in order to understand the response of mass balance to climatic variables. Energy balance numerical modelling provides quantification of the surface energy fluxes and identification of the factors affecting glacier mass balance. The model was validated by comparing the computed and observed ablation and surface temperature data. During the summer-monsoon period, net radiation was the primary component of the surface energy balance accounting for 80 % of the total heat flux followed by turbulent sensible (13%), latent (5%) and conductive (2%) heat fluxes. A striking feature of the energy balance is the positive turbulent latent heat flux, suggesting re-sublimation of moist air at the glacier surface, during the summer-monsoon characterized by relatively high air temperature, high relative humidity and a continual melting surface. The impact of the Indian Summer Monsoon on Chhota Shigri Glacier mass balance has also been assessed. This analysis demonstrates that the intensity of snowfall events during the summer-monsoon plays a key role on surface albedo (melting is reduced in the case of strong snowfalls covering the glacier area), and thus is among the most important drivers controlling the annual mass balance of the glacier. The summer-monsoon air temperature, controlling the precipitation phase (rain versus snow and thus albedo), counts, indirectly, also among the most important drivers.

Assessment of Lahaul-Spiti (western Himalaya, India) Glaciers- An Overview of Mass Balance and Climate

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.

Awareness of Climatic Variation through Indigenous Knowledge in Akungba-Akoko, Ondo State, Nigeria

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.

Reconstruction of the annual mass balance of Chhota Shigri glacier, Western Himalaya, India, since 1969

AbstractThis 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 air-temperature 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 -0.52 m w.e. a–1 °C–1 whereas the sensitivity to precipitation is calculated as 0.16mw.e.a-1 for a 10% change.

Dissolved ion chemistry and suspended sediment characteristics of meltwater draining from Chhota Shigri Glacier, western Himalaya, India

Studies on dissolved ion chemistry and suspended sediment concentration of meltwater draining from Chhota Shigri Glacier were carried out in the year 2008 and 2009. The cationic and anionic concentrations follow the trend: Ca2+ > Mg2+ > Na+ > K+ and HCO3 − > SO4 2− > Cl− > NO3 − > PO4 3−, respectively. The higher ratios of (Ca + Mg)/TZ+ and (Ca + Mg)/(Na + K); strong correlations between Ca-Mg, Ca-HCO3 and Mg-HCO3; and low ratio of (Na + K)/TZ+ for both the years indicate that chemical characteristics of Chhota Shigri Glacier meltwater are mostly controlled by carbonate weathering followed by silicate weathering. The C ratio shows that dissolution and dissociation of atmospheric CO2 is the major proton producer for glacier meltwater. Statistical analysis was used to identify different factors controlling dissolved ions chemistry of study area. There have been marked seasonal and diurnal variations in the total dissolved solid (TDS) and suspended sediment concentration of glacier meltwater observed during the sampling periods. TDS of meltwater is high during October (low discharge) and low during August (high discharge) in both years, implying that TDS is inversely correlated with discharge. On the other hand, suspended sediment concentration is higher during August (high flow regime) and low during October (low flow regime) during the sampling periods, generally following the discharge pattern of the glacier.

Study of solute sources and evolution of hydrogeochemical processes of the Chhota Shigri Glacier meltwaters, Himachal Himalaya, India

This study was carried out from 2003 to 2007 to understand the hydrogeochemical processes and the solute sources of the meltwaters of the Chhota Shigri Glacier, Himalaya. The meltwater is almost neutral to slightly alkaline in nature: bicarbonate and sulphate are the dominant anions, while calcium and magnesium are the dominant cations. Bicarbonate is found to be derived from carbonate weathering and partly from silicate weathering. Rock weathering followed by precipitation are the main controlling factors that influence the meltwater chemistry of this region. The relatively high values of pCO2 reflect a higher rate of solubility in comparison to release of excess CO2 gas to the atmosphere. The presence of active hydrogeochemical processes and sediment–water interaction results in excess solute transport through the meltwater to the Chandra River that feeds the Chenab, one of the great Himalayan river systems, and ultimately flows into the ocean. This study is the first of its kind to understand in detail the hydrogeochemical process and resultant solute load transport in this Himalayan glacier. Citation Sharma, P., Ramanathan, A.L., and Pottakkal, J., 2013. Study of solute sources and evolution of hydrogeochemical processes of the Chhota Shigri Glacier meltwaters, Himachal Himalaya, India. Hydrological Sciences Journal, 58 (5), 1128–1143. Editor Z.W. Kundzewicz

Temporal Variation in the Major Ion Chemistry of Chhota Shigri Glacier Meltwater, Lahaul–Spiti Valley, Himachal Pradesh, India

Glaciers, while commonly regarded as sensitive indicators of climate change, can also be affected by various factors like atmospheric deposition. Study of major ions (Mg2+, Ca2+, Na+, K+, HCO3 −, SO4 2− and Cl−) of meltwater draining from Chhota Shigri glacier was carried out to understand weathering and geochemical processes controlling the major ion chemistry of the glacier meltwater. Chhota Shigri glacier meltwater was sampled in August 2008. Mg2+ is the dominant cation followed by Ca2+, K+ and Na+. Whereas HCO3 − is the dominant anion followed by SO4 2− and Cl−. The high ratio of Ca + Mg/TZ+ i.e. 0.77 and low ratio of Na + K/TZ+ i.e. 0.23 shows that carbonate weathering is the dominant mechanism controlling major ion chemistry followed by silicate weathering in the study area. In this paper we aim to evaluate the possible effect of various processes that affect the chemistry of meltwater of Chhota Shigri glacier. Decadal variation in the major ion chemistry of Chhota Shigri glacier meltwater was carried out by comparing the hydrochemistry of August 2008 with previous study carried out in 1987. Comparison between the two data sets shows that cations like Ca2+ increased nearly 6 times, Mg2+ 87 times, Na+ 10 times and K+ 19 times, while anions like Cl− increased nearly 12 times, HCO3 − 85 times and SO4 2− 49 times between 1987 and 2008. This could be attributed to increased weathering rates due to climate warming, atmospheric deposition or a combination of both. Annual specific mass balance of Chhota Shigri glacier was often sharply negative during 2002–2010, pointing to glacier recession, which may be also attributed to global climatic change.