- Indian Institute of Science Education and Research Bhopal India, Department of Earth and Environmental Sciences, Bhopal, India (kumarp@iiserb.ac.in)
The global retreat of glaciers is a widely recognized indicator of climate change. However, the Karakoram region of the Himalayas defies this trend, exhibiting a unique phenomenon termed the “Karakoram Anomaly,” characterized by glacier stability or surges. This anomaly has been increasingly linked to the dynamics of western disturbances (WDs), upper-tropospheric synoptic systems propagating eastward along the subtropical westerly jet stream, critical drivers of winter precipitation in the region. This study synthesizes recent analyses of WDs using tracking algorithms applied to reanalysis datasets (ERA5, MERRA2, and NCEP-CFSR/CFSv2) to evaluate their role in sustaining the Karakoram Anomaly. While the frequency of WDs has remained relatively steady, a ∼10% increase in precipitation intensity associated with WDs over the anomaly core region has been observed in recent decades. The Karakoram receives approximately 65% of its total winter snowfall from WDs, emphasizing its pivotal role in modulating regional glacier mass balance. Concurrently, snowfall from non-WD sources has declined by ∼17%, further underscoring the significance of WDs. Changes in atmospheric dynamics, including enhanced baroclinic instability and a latitudinal shift in the subtropical westerly jet, have been identified as contributors to the increased intensity of WDs. Moreover, a statistically significant eastward shift (~9.7°E) in the genesis zone of WDs has been noted, resulting in enhanced cyclogenesis potential, higher moisture availability, and reduced propagation speeds. These factors collectively intensify WD-induced precipitation events over the Karakoram, supporting anomalous glacier behavior. This study highlights the critical influence of strengthening WDs on the Karakoram Anomaly, providing new insights into the interplay between atmospheric dynamics and regional glacier dynamics under climate change.
Keywords: Glaciers, Karakoram anomaly, Western Disturbances, TRACK
Acknowledgement: Funding from Science and Engineering Research Board (SERB), Govt. of India, grant number CRG/2021/00l227-G
How to cite: Kumar, P. and Javed, A.: Karakoram Anomaly and its connection with the Western Disturbances, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14227, https://doi.org/10.5194/egusphere-egu25-14227, 2025.
