The 2400 km long arcuate Himalaya-Hindu Kush mountain range supports largest accumulation of snow and ice following the Polar regions of Arctic and Antarctic and Greenland. Apart from the several peaks that attain more than 8000 m heights above mean sea level, the Himalaya also brings to life many major rivers that support ~1.3 billion people in one of the most densely populated regions of the world. Researchers have attempted to understand the feedback mechanism between climate forcing and glacier response by mapping of glacier characteristics such as their distribution pattern, changes in their length and thickness, mass-balance, basement topography etc. It has been established that adjoining glaciers can display dissimilar behaviour even in similar regional climatic settings due to varying geometry, bedrock topography or debris cover, thus necessitating their long term monitoring to arrive at a conclusion regarding their dynamics (Parmanand Sharma et al, 2016).
Bahuguna (2017) drawing greatly from IRS LISS IV image has depicted the morphological characteristics of a glacier from Zanskar Basin such as, accumulation and ablation zones, snout, snow line, moraines and tributary glacier joining the main trunk glacier (Fig. 1). Recognition of the changes in these surface morphological features such as the distribution of moraines, snout position, zones of accumulation and ablation etc are important for appreciating responses to climate change.
The data compiled by Bhutiyani (2013) shows that elevation-dependent warming (EDW) can accelerate the rate of change in mountain ecosystems, cryospheric systems, hydrological regimes and biodiversity (also see Pepin et al., 2015).The Himalaya has a profound impact on regional climate and its cryosphere gets affected by changing climatic systems. The Himalaya is warming much faster than the rest of the globe. It affects wind circulation and storm tracks over large distances. The high altitude segments of Himalaya)—the Siwaliks (>3000m), Pirpanjal (>5000m), Greater Himalayan Ranges (>6000 to 7000m), Zanskar Range (>7000m) exhibit warming trends while decreasing trends are noted only in the Karakorum range (>8000m). Due to its unique geographic, orographic position and high altitude, it faces rapid changes in the weather patterns and ecosystem.
The glaciers, snow-capped mountains, permafrost soils; cold deserts and wetlands hold large reserves of carbon. Climate change processes have caused changes in rainfall pattern, recession of glaciers, loss of snow cover, scarcity of water and forced changes in cultivation patterns, bringing the Himalayan earth system to a critical stage that necessitates intervention for its protection and preservation.
Monitoring, studying and understanding various scientific and related social aspects of the Himalaya pertaining to meteorological parameters, hydrological cycle and glaciers are of vital importance for managing river flows, irrigation, power generation, conserving the biodiversity and sustaining the life systems of the Himalayan terrain, the people and the plains below. Glacier melt water discharge measurement by the Geological Survey of India (Shukla, 2017) in Hamtah glacier shows strong positive and significant correlation with temperature as well as ablation and relatively weak correlation with precipitation. The glacier also does not show any appreciable lag between ice melt generation and its release and thereby indicates that there is no storage of glacier melt within the glacier.
The glacier inventory of the Himalaya prepared by Space Applications Centre (SAC) identifies a total of 34919 glaciers that occupy an area of around 75,779 sq km (Sharma et al., 2013) (Fig 2). The distribution of these glaciers in three main basins—the Indus, the Ganga and the Brahmaputra is as given in Fig 1.
SAC is also undertaking snow cover mapping as also mapping and monitoring of glacial and peri-glacial lakes in the Indian Himalayan region to develop a model for glacial lake outbursts (GLOF) hazard based on vulnerability Index (Bahuguna, 2017). The results of studies published by SAC on the long term monitoring of snout of glaciers in three main basins-Ganga, Indus and Brahmaputra in the two periods of 1989-90 to 2001-04 and 2001-02 to 2010-11 have presented a contrasting picture. During the period of 1989-90 to 2001-2004, 76 per cent of the glaciers have shown retreat, 7 per cent have advanced and 17 per cent have shown no change. As compared to this, during the next decade i.e. 2001-02 to 2010-11, only 12.3 per cent glaciers have shown retreat, 86.6 per cent of glaciers have shown stable fronts and 0.9 per cent have shown advancement (Ajai, 2017).
Romshoo (2017) has pointed out that the Kashmir Himalayas have lost ~20 per cent of the glacial mass during last six decades. He has cautioned that shifting of hydrograph peaks, change in the precipitation and low availability of storage capacity of water in Kashmir should be a matter of grave concern for policy makers and that water issues, if, not understood in the right perspective have the potential to complicate south Asian security.
Data provided by Ramanathan (2017) states a total mass change of -16.3±3.5 Gt per yr between 2000 and 2016 for the Himalayan glaciers, which is less negative than most of the previous estimates, while region-wide mass balances vary from -4.0±1.5 Gt per yr (-0.62 m w.e. per yr) in Nyainqentanglha (Tibet, China) to +1.4±0.8 Gt per yr(+0.14 m w.e. per yr) in Kunlun.
Apart from SAC the multiple agencies in India—several universities, Geological Survey of India, Wadia Institute of Himalayan Geology, the National Institute of Hydrology, National Centre for Antarctica and Ocean Research etc., are monitoring various glaciers by field and remote sensing techniques showing a wide mismatch in the findings. This highlights the need for the standardisation of tools and techniques and parameterisation as also necessary for ground checks of the interpreted results from satellite data. Ravindra (2017) has highlighted a need for coordination among these institutions to ensure proper utilisation of scarce manpower in the field of glaciology and also to cover more and more the spread of glaciers. The quantitative data on dating of moraines, though is gaining ground, yet much needs to be done to obtain luminescence (TL) or optically stimulated luminescence (OSL) and cosmogenic dates to build a history of the nature of glaciers in Holocene, Little Ice Age etc.
The Himalayan ecosystem is vital to the ecological security of the Indian landmass. It is highly vulnerable and susceptible to the impacts and consequences of excessive anthropogenic emissions and developmental paradigms of modern society. It needs to be protected to conserve its biodiversity for providing a rich base for high value agriculture, and the development of sustainable tourism. The issues pertaining to the preservation and protection of this fragile Himalayan ecosystem, understanding the coupling between this ecosystem and climate factors and providing inputs for Himalayan sustainable development come under the preview of the National Action Plan on Climate Change (NAPCC).
Ajai, 2017. Inventory and monitoring of Snow and Glaciers of the Himalaya using Space data. (In) Goel, P. S., Ravindra, R., and Chattopadhyay, S (Eds.), Science and Geopolitics of the White World, Arctic-Antarctic-Himalaya. Springer Polar Geography, Springer International Publishing, 95-113.
Bahuguna, I. M., 2017. Observing Himalayan and polar cryosphere through Indian satellites. Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 103-104.
Bhutiyani, M.R., 2017. An overview of high altitude warming to the Himalayas: A study based on instrumental records and land surface temperatures (LST) derived from Landsat – 5 TM and OLI data Abstract. Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 135-136.
Pepin, N., Bradley, R. S., Diaz, H. F., Baraer, M., Caceres, E. B., Forsythe, N., Fowler, H., Greenwood, G., Hashmi, M. Z., Liu, X. D., Miller, J. R., Ning, L., Ohmura, A., Palazzi, E., Rangwala, I., Schöner, W., Severskiy, I., Shahgedanova, M., Wang, M. B., Williamson, S. N., and Yang, D. Q., 2015. Mountain Research Initiative EDW Working Group. Elevation-dependent warming in mountain regions of the world. Nature Climate Change, 5: 424–430.
Ramanathan, A. L., Sharma, P., Mandal, A., Angchuk, T., Patel, L., Kumar, N., Soheb, M., Ranjan, S., Mishra, S.D., and Vatsal, S., 2017. Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 134.
Ravindra, R., 2017. Polar Regions and the Climate Scenario. Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 110.
Romshoo, S.A., 2017. Melting Third Pole: Driving Factors and Consequences. Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 137-138.
Sharma, P., Patel, LK., Ravindra, R., Singh, A., Mahalinganathan, K., and Thamban, M., 2016. Role of debris cover to control specific ablation of adjoining Batal and Sutri Dhaka glaciers in Chandra Basin (Himachal Pradesh) during peak ablation season. Journal of Earth System Sciences, 125(3): 459-473.
Sharma A.K., Singh S., and Kulkarni, A.V., 2013. Glacier Inventory in Indus, Ganga and Brahmputra basins of the Himalaya. National Academy Science Letter, 36(5):497-505.
Shukla, S.P., Rakesh Mishra and Ajai Kumar. Glacier melts water characteristics of Hamtah glacier, Lahaul and Spiti district, Himachal Pradesh, India. 2017 Abstract 4th Conference on Science and Geopolitics of Himalaya-Arctic-Antarctic (SaGHAA 2017) Nov. 30 – Dec. 1, 2017, Jawaharlal Nehru University, New Delhi, India, 146.
Inputs from : Dr I M Bahuguna, Scientist G, Space Applications Centre, ISRO. firstname.lastname@example.org