Fig. 7
Conceptual schematic illustrating the teleconnection between Arctic sea ice melt and the Indian Summer Monsoon Rainfall. The left side of the figure depicts a sequence of processes initiated by Arctic warming and sea ice melt. The retreat of Arctic sea ice, particularly in the Barents–Kara sector, is accompanied by Atlantification—intrusion of warmer Atlantic waters into the Arctic Ocean—which enhances local ocean-atmosphere heat exchange. This process contributes to Arctic Amplification characterized by a faster rate of warming in the Arctic compared to the global average. The amplified Arctic warming is associated with the weakening of the winter polar vortex and modifications in planetary wave activity, which in turn result in the enhanced meandering of the mid-latitude jet streams. These altered jet streams propagate downstream and impact the lower latitudes, including South Asia. The right side of the figure zooms into India, where the downstream impact manifests as subsidence (downward air motion) over the Indo-Gangetic region (oval shape marked in black dotted lines). This atmospheric subsidence is associated with reduced vertical motion and diminished convective activity, leading to less buoyant air parcels and thereby suppressing rainfall in this region. Collectively, the schematic highlights a potential diagnostic pathway through which Arctic sea ice variability may influence the strength and spatial variability of the ISMR.
