Climate change over Leh (Ladakh), India

Mountains over the world are considered as the indicators of climate change. The Himalayas are comprised of five ranges, viz., Pir Panjal, Great Himalayas, Zanskar, Ladhak, and Karakorum. The Ladakh region lies in the northernmost state of India, Jammu and Kashmir, in the Ladhak range. It has a unique cold-arid climate and lies immediately south of the Karakorum range. With scarce water resources, such regions show high sensitivity and vulnerability to the change in climate and need urgent attention. The objective of this study is to understand the climate of the Ladakh region and to characterize its changing climate. Using different temperature and precipitation datasets over Leh and surrounding regions, we statistically analyze the current trends of climatic patterns over the region. The study shows that the climate over Leh shows a warming trend with reduced precipitation in the current decade. The reduced average seasonal precipitation might also be associated with some indications of reducing number of days with higher precipitation amounts over the region

Comparison of climatic trends and variability among glacierized environments in the Western Himalayas

The climate and hydrology of the Western Himalayas is complex and a function of snow and glacier melt, land use, topography, and Indian summer and winter monsoon dynamics. Improving our knowledge about these processes is important from societal and agricultural points of view. In this study, an observational analysis is carried out to assess the changing climatic trends and the associated interannual variability in winter temperature and precipitation at three glacierized regions of Western Himalayas having distinctly different sub-regional characteristics. In situ observations of 23 years (1985–2007) are used. These observations are passed through rigorous statistical quality control checks. Results show higher interannual variability with increasing temperature trends in the glacierized regions of the Siachen (Karakoram Range) and Chotasigri (Great Himalayan Range). Karakoram Range has higher warming trends than the Great Himalayan Range. In case of precipitation, an overall decrease in precipitation is observed with contrasting trends in the last decade. Nino3.4 index is positively correlated with winter precipitation with similar interannual variability. In addition, at Siachen temperature and precipitation show strong negative correlation, and precipitation to spell length correlation is opposite at Siachen and Chotasigri

Cloudbursts in Indian Himalayas: a review

Cloudbursts in and around the southern rim of the Indian Himalayas are elusive in terms of their position and time of occurrences. Most of the reported cloudbursts are in the interior of the Himalayas and hence their observation itself is limited. Most of these events are reported once their affect in terms of loss to life and property is experienced in the downstream habitats. In addition, they are mostly associated with flash floods as an impact of the torrential precipitation. The principal understanding of the cloudburst is associated with sudden heavy deluge of precipitation in very less time interval over a very small area. Except this understanding and India Meteorology Department (IMD) definition of > 100 mm/h precipitation over a geographical region of approximately 20–30 km2, nothing much else is known about these events. There are a very few studies carried out on understanding of these events. Present paper synthesizes the available information and research on cloudburst events and tries to define it based on associated dynamics, thermodynamics and physical processes leading to a cloudburst event. Thus in the present work, characterizations and impacts of cloudburst leading from precipitation to dynamical to thermodynamical to large scale forcings to orographical forcings to followed geomorphology to impacts are intertwined to present comprehensive portray of it. Most of the cloudburst events are seen occurring in the elevation range of 1000 m to 2500 m within the valley folds of the southern rim of the Indian Himalayas. Apart from some of the large scale flow shown by few of the studies, it is found that cloudburst events are convectively triggered followed by orographically locked systems. These intertwined mechanisms lead cloudburst events to form. Amiss of any one of these mechanisms will not lead the cloudburst mechanism to form. These interactions in the present paper established the vagaries associated with the cloudburst events

Supraglacial ponds regulate runoff from Himalayan debris-covered glaciers

Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one fifth of the Earth's population. Between 13% and 36% of the region's glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu Glacier, Nepal, spanning a seven-month period in 2014. Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs. Diurnally, the supraglacial pond system may store >23% of observed mean daily discharge, with mean recession constants ranging from 31 to 108 hours. Given projections of increased debris-cover and supraglacial pond extent across High Mountain Asia, we conclude that runoff regimes may become progressively buffered by the presence of supraglacial reservoirs. Incorporation of these processes is critical to improve predictions of the region's freshwater resource availability and cascading environmental effects downstream

Cosmic-ray soil water monitoring: the development, status & potential of the COSMOS-India network

Soil moisture (SM) plays a central role in the hydrological cycle and surface energy balance and represents an important control on a range of land surface processes. Knowledge of the spatial and temporal dynamics of SM is important for applications ranging from numerical weather and climate predictions, the calibration and validation of remotely sensed data products, as well as water resources, flood and drought forecasting, agronomy and predictions of greenhouse gas fluxes. Since 2015, the Centre for Ecology and Ecology has been working in partnership with several Indian Research Institutes to develop COSMOS-India, a new network of SM monitoring stations that employ cosmic-ray soil moisture sensors (CRS) to deliver high temporal frequency, near-real time observations of SM at field scale. CRS provide continuous observations of near-surface (top 0.1 to 0.2 m) soil volumetric water content (VWC; m3 m-3) that are representative of a large footprint area (approximately 200 m in radius). To date, seven COSMOS-India sites have been installed and are operational at a range of locations that are characterised by differences in climate, soil type and land management. In this presentation, the development, current status and future potential of the COSMOS-India network will be discussed. Key results from the COSMOS-India network will be presented and analysed

Role of glaciers in watershed hydrology: a preliminary study of a "Himalayan catchment"

A large number of Himalayan glacier catchments are under the influence of humid climate with snowfall in winter (November–April) and south-west monsoon in summer (June–September) dominating the regional hydrology. Such catchments are defined as "Himalayan catchment", where the glacier meltwater contributes to the river flow during the period of annual high flows produced by the monsoon. The winter snow dominated Alpine catchments of the Kashmir and Karakoram region and cold-arid regions of the Ladakh mountain range are the other major glacio-hydrological regimes identified in the region. Factors influencing the river flow variations in a "Himalayan catchment" were studied in a micro-scale glacier catchment in the Garhwal Himalaya, covering an area of 77.8 km<sup>2</sup>. Three hydrometric stations were established at different altitudes along the Din Gad stream and discharge was monitored during the summer ablation period from 1998 to 2004, with an exception in 2002. These data have been analysed along with winter/summer precipitation, temperature and mass balance data of the Dokriani glacier to study the role of glacier and precipitation in determining runoff variations along the stream continuum from the glacier snout to 2360 m a.s.l. The study shows that the inter-annual runoff variation in a "Himalayan catchment" is linked with precipitation rather than mass balance changes of the glacier. This study also indicates that the warming induced an initial increase of glacier runoff and subsequent decline as suggested by the IPCC (2007) is restricted to the glacier degradation-derived component in a precipitation dominant Himalayan catchment and cannot be translated as river flow response. The preliminary assessment suggests that the "Himalayan catchment" could experience higher river flows and positive glacier mass balance regime together in association with strong monsoon. The important role of glaciers in this precipitation dominant system is to augment stream runoff during the years of low summer discharge. This paper intends to highlight the importance of creating credible knowledge on the Himalayan cryospheric processes to develop a more representative global view on river flow response to cryospheric changes and locally sustainable water resources management strategies

Comparison of climatic trends and variability among glacierized environments in the Western Himalayas

The climate and hydrology of the Western Himalayas is complex and a function of snow and glacier melt, land use, topography, and Indian summer and winter monsoon dynamics. Improving our knowledge about these processes is important from societal and agricultural points of view. In this study, an observational analysis is carried out to assess the changing climatic trends and the associated interannual variability in winter temperature and precipitation at three glacierized regions of Western Himalayas having distinctly different sub-regional characteristics. In situ observations of 23 years (1985–2007) are used. These observations are passed through rigorous statistical quality control checks. Results show higher interannual variability with increasing temperature trends in the glacierized regions of the Siachen (Karakoram Range) and Chotasigri (Great Himalayan Range). Karakoram Range has higher warming trends than the Great Himalayan Range. In case of precipitation, an overall decrease in precipitation is observed with contrasting trends in the last decade. Nino3.4 index is positively correlated with winter precipitation with similar interannual variability. In addition, at Siachen temperature and precipitation show strong negative correlation, and precipitation to spell length correlation is opposite at Siachen and Chotasigri

Climate change, cryosphere and impacts in the Indian Himalayan Region

This study has benefitted from collaborations promoted by the Indian Himalayas Climate Adaptation Programme (www.ihcap.in), a project under the Global Programme Climate Change and Environment of the Swiss Agency for Development and Cooperation in cooperation with the Department of Science and Technology, Government of India (GoI), and with support from the Government of Himachal Pradesh and National Mission of Himalayan Studies, Ministry of Environment, Forest and Climate Change, GoI.Climate change and related impacts over the Indian Himalayan Region (IHR) remains poorly quantified. The present study reviews observed and modelled changes in the climate, cryosphere and impacts related to hazards, agriculture and ecosystems. An increasing temperature trend over the IHR is reported, which over a few locations is found to be higher than the global average. For precipitation, a complex and inconsistent response with considerable variation in the sign and magnitude of change is observed. Future projections show significant warming. Climate-driven changes and impacts are clearly observed. Snow cover has declined since the 1960s, with an enhanced decreasing trend during the 1990s and variable trends since 2000. Glaciers are losing mass and retreating at varying rates since the early 20th century, with an exception over the Karakoram region. An observed heterogeneous response of glaciers to atmospheric warming is controlled by regional variations in topography, debris cover, circulation and precipitation. Initial assessments of permafrost extent of 1 million km(2) across the IHR roughly translate into 14 times the glacier area. Extreme floods represent the most frequent natural disaster in the IHR. Studies have highlighted the significant threat from glacial lakes. Landslides occur in combination with heavy rainfall and flooding, with poor land- use practices such as road-cutting and deforestation being additional drivers. Climate change has also stressed traditional subsistence agriculture and food systems. Improving systematic and coordinated monitoring of climate and related impacts is crucial to contribute to effective climate change adaptation and response strategies.Publisher PDFPeer reviewe