Publication Date:
2013-06-21
Description:
[1] The coupled regional climate model HIRHAM-NAOSIM is used to investigate feedbacks between September sea-ice anomalies in the Arctic and atmospheric conditions in autumn and the subsequent winter. A six-member ensemble of simulations spanning the period 1949-2008 is analyzed. The results show that negative Arctic sea-ice anomalies are associated with increased heat and moisture fluxes, decreased static stability, increased lower-tropospheric moisture, and modified baroclinicity, synoptic activity and atmospheric large-scale circulation. The circulation changes in the following winter display meridionalized flow, but are not fully characteristic of a negative Arctic Oscillation pattern, though they do support cold winter temperatures in northern Eurasia. Internally generated climate variability cause significant uncertainty in the simulated circulation changes due to sea ice - atmosphere interactions. The simulated atmospheric feedback patterns depend strongly on the position and strength of the regional sea-ice anomalies and on the analyzed time period. The strongest atmospheric feedbacks are related with sea-ice anomalies in the Beaufort Sea. This work suggests that there are complex feedback mechanisms that support a statistical link between reduced September sea ice and Arctic winter circulation. However the feedbacks depend on regional and decadal variations in the coupled atmosphere-ocean-sea ice system.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
Permalink
