Fig. 5. Schematic showing changes in the Arctic atmosphere–sea ice–ocean system caused by riverine heat.

Anomalous riverine heat Q_rh influx ① results in ② sea-ice reduction including loss of ice area, thickness, and longer ice-free periods, ③ ocean warming, ④ positive feedback caused by additional sea ice retreat and enhanced absorption of atmospheric heat, and ⑤ additional atmospheric warming caused by anomalous release of ocean heat into the atmosphere. The thicker vertical and horizontal arrows indicate larger heat fluxes or inflows.