11:00 AM - 1:00 PM
[ACG43-P03] Atmospheric warming over the Barents Sea during moisture intrusion events in January 2006
Keywords:Arctic Amplification, Sea ice, Numerical simulation
Recent studies suggest the long-term trend of Arctic warming during winter is attributable to increased frequency of occurrence of moisture intrusion events from lower latitudes, but that sea ice loss is also one of the fundamental controlling processes; however, the relative importance of their roles remains disputed. Using numerical simulations, this study examined the impact of sea ice cover on atmospheric warming during moisture intrusion events in January 2006. Atmospheric warming due to sea ice loss could well explain the horizontal distribution of the observed temperature anomaly in January 2006, indicating the importance of sea ice loss in relation to recent Arctic warming. It was found that cooling (warming) due to divergence (convergence) of downward (upward) longwave radiation was weakened (enhanced) by sea ice loss, producing a net result of stronger radiative heating. This finding corroborates recent data analysis studies that inferred interaction between sea ice loss and radiative heating. The results indicate that enhanced radiative heating is attributable to changes in the vertical distributions and phases of hydrometeors caused by more unstable near-surface conditions and stronger ascent.