|Title||Episodic Southern Ocean heat loss and its mixed layer impacts revealed by the farthest south multiyear surface flux mooring|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Ogle S.E, Tamsitt V., Josey S.A, Gille ST, Cerovecki I, Talley LD, Weller RA|
|Journal||Geophysical Research Letters|
|Type of Article||Article|
|Keywords||air-sea heat flux; antarctic mode water; anthropogenic carbon; co2; Geology; interannual variability; intermediate water; mixed layer; mooring; sea interaction research; Southern Ocean; Subantarctic Mode Water; transport; variability|
The Ocean Observatories Initiative air-sea flux mooring deployed at 54.08 degrees S, 89.67 degrees W, in the southeast Pacific sector of the Southern Ocean, is the farthest south long-term open ocean flux mooring ever deployed. Mooring observations (February 2015 to August 2017) provide the first in situ quantification of annual net air-sea heat exchange from one of the prime Subantarctic Mode Water formation regions. Episodic turbulent heat loss events (reaching a daily mean net flux of -294W/m(2)) generally occur when northeastward winds bring relatively cold, dry air to the mooring location, leading to large air-sea temperature and humidity differences. Wintertime heat loss events promote deep mixed layer formation that lead to Subantarctic Mode Water formation. However, these processes have strong interannual variability; a higher frequency of 2 sigma and 3 sigma turbulent heat loss events in winter 2015 led to deep mixed layers (>300m), which were nonexistent in winter 2016.