open access

https://doi.org/10.14943/lowtemsci.76.13

https://hdl.handle.net/2115/70322

Sea-ice production in Antarctic coastal polynyas and bottom water formation

日本語

Cape Darnley Polynya

2018-03-31

低温科学第76巻編集委員会

Low Temperature Science

76

13-23

Global overturning circulation is driven by density differences. Saline water rejected by sea-ice production in coastal polynyas is the main source of dense water, and thus sea-ice production is a key factor in the overturning circulation. The mapping of sea-ice production derived from satellite microwave radiometer data demonstrates that ice production rate is high in Antarctic coastal polynyas, in contrast to Arctic coastal polynyas. This is consistent with the formation of Antarctic Bottom Water (AABW), the densest water mass which occupies the abyssal layer of the global ocean. The Ross Ice Shelf polynya has by far the highest ice production in the Southern Hemisphere. The Cape Darnley polynya is found to be the second highest production area, leading to the discovery of the missing (fourth) source of AABW in this region. In the region off the Mertz Glacier Tongue, the third source of AABW, sea-ice production in the Mertz polynya decreased by as much as 40 %, due to the glacier calving in early 2010, resulting in a significant decrease in AABW production.

紀要論文

Version of Record

1880-7593

AA12122962