Mid-Latitude Atmospheric Response to Anomalous Arctic Autumn Surface Heating
Abstract
One of the most striking recent changes in climate is the reduction of sea ice extent in the Arctic. This reduction of sea ice extent allows for open water to persist later in autumn leading to increased surface temperature and a large exchange of heat between these warm, open water areas and the atmosphere. Using four reanalysis datasets and a self-organizing map framework, this anomalous heating during autumn is analyzed to determine both the local, immediate and the downstream, delayed impact on the atmospheric state, circulation, and fluxes, particularly in the mid-latitudes. SOM-identified patterns with increased surface temperature, corresponding to reduced sea ice extent in the GIN seas region are persistent through much of the autumn. This persistent surface anomaly leads to a local maximum in 1000-500mb thickness and a 500mb ridge in this area. This perturbation of the 500 mb heights results in persistent northerly flow, cold surface temperature anomalies, and a 500 mb trough over Eurasia several weeks after the initial surface temperature anomaly appears.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C21C0696C
- Keywords:
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- 3349 Polar meteorology;
- ATMOSPHERIC PROCESSESDE: 0750 Sea ice;
- CRYOSPHEREDE: 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERALDE: 4540 Ice mechanics and air/sea/ice exchange processes;
- OCEANOGRAPHY: PHYSICAL