Does the Antarctic Slope Current control the heat transport towards Antarctica?
Wilton Aguiar
The ocean heat transport towards Antarctica directly drives the melting of Antarctic ice shelves, modulating sea level rise. A common assumption is that heat transport across the Antarctic continental slope is modulated by the strength of the Antarctic Slope Current (ASC). The main dynamic explanation for this assumption is that the frontal structure of the ASC acts as a barrier to cross-slope heat transport from the Circumpolar Deep Water (CDW). However, observations of the ASC are too scarce to investigate its relationship to poleward heat transport across large circumpolar spatial scales, or over long temporal scales. This study quantifies the relationship between ASC speed and the cross-slope heat transport from CDW using an interannual simulation with the ACCESS-OM2-01 ocean and sea ice model, with 0.1o horizontal resolution. We find primarily low coefficients of determination (r² < 0.6) between ASC strength and cross-slope heat transport from CDW, except at a few locations, such as near the Getz (r² = 0.64) and Glomar ice shelves (r² = 0.65), and on the northern edge of the West Antarctic Peninsula (r² = 0.61). These results suggest that the ASC does not control cross-slope heat transport from CDW along most of the Antarctic continental shelf, as is often assumed.
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