The Kamchatka Strait, the westernmost and deepest passage of the Aleutian Archipelago, serves as the primary deep-water conduit for mass and heat exchange between the North Pacific and the Bering Sea. Understanding its circulation is crucial for characterizing the Bering Sea's hydrographic regime, yet study remains challenging due to extreme climatic forcing and complex bathymetry. This study investigates the variability of water circulation within the strait during the critical spring transition (May–June) from 1950 to 2017, utilizing numerical modeling and Ocean Data View (ODV) statistical analysis.
Our results demonstrate that the seasonal shift from winter to summer monsoons triggers a fundamental restructuring of the current system. While cyclonic flow generally dominates the Aleutian-Bering system, the spring season marks a significant weakening of cyclonic activity in the Kamchatka Strait, giving way to anticyclonic gyres. These structures facilitate a substantial seasonal inflow of warm Pacific waters into the Bering Sea basin. During this period, the Kamchatka Current loses its spatial continuity, bifurcating into several hydrodynamic eddies. These findings identify the May–June period as a critical threshold, where hydrodynamic instability reflects the non-linear nature of seasonal atmospheric shifts governing the Bering Sea’s water balance.
 

Kamchatka Strait,,Bering Sea,,water circulation,,numerical modeling,,Pacific–Bering Sea exchange,,anticyclonic gyres.