Spatially heterogeneous glacier elevation change in the Jankar Chhu Watershed, Lahaul Himalaya, India derived using ASTER DEMs
Creators: name: Das, Suresh
name: Sharma, Milap Chand
name: Murari, Madhav Krishna
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biochemistry
subject: Physiology
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: Astronomical and Space Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: This study investigates elevation change (<i>dh</i>) and geodetic mass budget of glaciers in the Jankar Chhu Watershed (JCW), Lahaul Himalaya, India, based on the difference in ASTER DEMs during 2002–2018. Glacier-wide spatially heterogeneous <i>dh</i> patterns were evaluated in the context of morphological and topographical settings. During 2002–2018, glaciers show a mean annual elevation change rate (<i>dh/dt</i>) of −0.38 ± 0.10 m a<sup>−1</sup>, resulting in a specific mass budget of −0.32 ± 0.09 m w.e.a<sup>−1</sup>, close to the previously reported estimates in western Himalaya. Nearly stagnant thick debris-covered tongue (&gt;10% debris cover) characterized by melt hotspots exhibits maximum <i>dh</i> at up-glacier instead of the terminus. Debris-free glaciers (&lt;10% debris cover) show maximum <i>dh</i> near the terminus. Spatially heterogeneous <i>dh</i> under varying debris cover is interpreted as an insulating effect of debris thickness as validated by field measurements. We suggest that elevation change of debris-covered glaciers cannot be generalized and glacier-wide spatially detailed mapping of <i>dh</i> is necessary to better understand the control of different surface morphology under warming climatic conditions in the western Himalayas. We present a spatially heterogeneous elevation change rate of 33 glaciers (150.9 km<sup>2</sup>) in the Jankar Chhu Watershed (JCW), Chandrabhaga basin, Western Himalaya based on the differences of ASTER digital elevation models (DEMs).We estimate the altitude-dependent elevation change of glaciers under varying debris thickness and surface morphology.Glaciers in the JCW show mean <i>dh/dt</i> of –0.38 ± 0.10 m a<sup>−1</sup>, resulting in a specific mass budget of –0.32 ± 0.09 m w.e.a<sup>−1</sup>, close to the previously reported estimates in western Himalaya.Debris-covered ice exhibits higher elevation change than debris-free ones.Thick debris-covered tongues show maximum surface lowering at up glaciers while debris-free tongue exhibits maximum lowering near the terminus.Debris thickness controls the altitude-wise spatial elevation change pattern in the JCW. We present a spatially heterogeneous elevation change rate of 33 glaciers (150.9 km<sup>2</sup>) in the Jankar Chhu Watershed (JCW), Chandrabhaga basin, Western Himalaya based on the differences of ASTER digital elevation models (DEMs). We estimate the altitude-dependent elevation change of glaciers under varying debris thickness and surface morphology. Glaciers in the JCW show mean <i>dh/dt</i> of –0.38 ± 0.10 m a<sup>−1</sup>, resulting in a specific mass budget of –0.32 ± 0.09 m w.e.a<sup>−1</sup>, close to the previously reported estimates in western Himalaya. Debris-covered ice exhibits higher elevation change than debris-free ones. Thick debris-covered tongues show maximum surface lowering at up glaciers while debris-free tongue exhibits maximum lowering near the terminus. Debris thickness controls the altitude-wise spatial elevation change pattern in the JCW.