Barents sea inflow shutdown: a new mechanism for rapid climate changes

Abstract

A new mechanism for rapid climate transitions in the high latitudes is presented which involves complex ocean-sea ice-atmosphere interactions. A shutdown of the Barents Sea Inflow (BSI) which carries a vast amount of heat into the Arctic Ocean is at the heart of the mechanism. The BSI shutdown is studied in a multi-millennium integration with a global climate model forced by periodically (1000 yr) varying solar constant (±2 W/m2). A positive feedback between the inflow and sea ice cover is revealed in the model, which triggers rapid climate changes. The BSI shutdown events are associated with strong cooling in the northern latitudes and subsequent rearrangement of the Arctic Ocean surface current system. The results reveal the existence of a bifurcation point in the Arctic climate system and demonstrate that rapid climate transitions may be caused by local feedbacks and restricted to confined areas without significant global impacts Copyright 2009 by the American Geophysical Union.