Abstract
High-altitude meteorological data are scarce in the Himalayan region, particularly for glacierized catchments. In-depth knowledge of meteorological variables is crucial to describe numerous cryospheric processes and associated hazards. The present study comprehensively assesses time series data (2013–16) of meteorological parameters in the Chorabari Glacier catchment (CGC) using an automatic weather station (∼4270 m MSL). Results revealed that average near-surface air temperature varied seasonally, ranging from 6.4°C in the summer monsoon (June–September) to −6.3°C in the winter season (December–February). The minimum temperature (Tmin) remained positive throughout the monsoon seasons in the higher elevations (∼5050 m MSL), indicating the melting of glaciers and their reduced mass. The daily relative humidity in different seasons fluctuated from 39% to 90%, whereas the highest seasonal average (∼63%) was observed in the monsoon season. The average wind speed was high (∼1.7 m s−1) during winter and dropped to 1.1 m s−1 in the monsoon season. The average daily influx of solar radiation ranged from 19 to 374 W m−2, with the highest value recorded during the premonsoon (March–May ∼ 212 W m−2) and the lowest during the winter (∼149 W m−2) season. The daily outflux solar radiation varied from 18 to 186 W m−2, with the maximum value in premonsoon (∼145 W m−2) and the minimum value in the monsoon season (∼30 W m−2). The mean zero-degree isotherm was found above the equilibrium line altitude (ELA ∼ 5120 m MSL) during the monsoon season, indicating a considerable mass depletion of the Chorabari Glacier. The abnormal variations in climatic variables on 16–17 June 2013 were signs of the Kedarnath disaster.
Significance Statement
The main objective of this study is to understand the variability of meteorological drivers at daily, monthly, and seasonal scales and how these changes may impact glacier mass and downstream hydrology. Our research revealed considerable variations in maximum temperature throughout the year and positive minimum temperature at higher elevations during monsoon months, which significantly control the glacier mass changes. Meteorological variables showing cyclic behavior and indicators of the “monsoon lowering phenomenon” are important in determining the timing and intensity of the seasonal shift. Investigation of abnormal changes in the climatic drivers in the 2013 Kedarnath disaster provides valuable insight into the glacier-related hazards and draws attention to decision-makers to create robust strategies to monitor the dynamic response of Himalayan glaciers.
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