Multi–parametric approach using SAR data for Siachen glacier dynamics in the Karakoram Himalaya

: The study focuses on the Siachen Glacier and uses Sentinel-1A Synthetic Aperture Radar (SAR) data between 2017 and 2024 to explore glacier dynamics, i.e., glacier mass balance (GMb), equilibrium line altitude (ELA), facies classification, and surface velocity. High-level SAR processing techniques, e.g., application of orbit files, thermal noise removal, calibration, and terrain correction, were carried out by using the Sentinel Application Platform (SNAP). Four zones—Frozen Percolation Zone (FPZ), Wet Snow Zone (WSZ), Bare Ice Zone (BIZ), and Debris-Covered Ice Zone (DCIZ)—were inferred for glacier facies using backscatter thresholds derived from VV and VH polarizations. Dynamic distribution of facies is captured in the results with significant fluctuation in the WSZ, general decrease in the BIZ, changing debris coverage in the DCIZ, and a constant FPZ. The average ELA was 5612.48 ±203.2 m, and the average GMb was -0.668 ±0.2 meters water equivalent (m w.e.) y -1 , showing sustained loss of ice mass dominated by climatic variability, a pattern observed in most Himalayan glaciers. Glacier retreat and variation in GMb have been linked to variation in climatic conditions, which has resulted in sustained loss of ice over the years. Surface velocity analysis revealed values ranging from 2.63 to 176.43 ±2.3 m y -1 , with maximum velocities observed in 2021, indicating periods of dynamically enhanced glacier flow. Overall, the study demonstrates the effectiveness of multi-temporal SAR data for long-term, weather-independent monitoring of glacier facies, GMb, and flow dynamics in the Karakoram Himalaya.