Climatic modulation of surface acidification rates through summertime wind forcing in the Southern Ocean
|Author(s)||Xue Liang1, 2, Cai Wei-Jun3, Takahashi Taro4, Gao Libao1, 2, Wanninkhof Rik5, Wei Meng1, 2, Li Kuiping1, 2, Feng Lin1, 2, Yu Weidong1, 2|
|Affiliation(s)||1 : State Ocean Adm, Inst Oceanog 1, Qingdao 266061, Peoples R China.
2 : Qingdao Natl Lab Marine Sci & Technol, Lab Reg Oceanog & Numer Modeling, Qingdao 266237, Peoples R China.
3 : Univ Delaware, Sch Marine Sci & Policy, Newark, DE 19716 USA.
4 : Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA.
5 : NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA.
|Source||Nature Communications (2041-1723) (Nature Publishing Group), 2018-08 , Vol. 9 , P. 3240 (11p.)|
|WOS© Times Cited||31|
While the effects of the Southern Annular Mode (SAM), a dominant climate variability mode in the Southern Ocean, on ocean acidification have been examined using models, no consensus has been reached. Using observational data from south of Tasmania, we show that during a period with positive SAM trends, surface water pH and aragonite saturation state at 60 degrees-55 degrees S (Antarctic Zone) decrease in austral summer at rates faster than those predicted from atmospheric CO2 increase alone, whereas an opposite pattern is observed at 50 degrees-45 degrees S (Subantarctic Zone). Together with other processes, the enhanced acidification at 60 degrees-55 degrees S may be attributed to increased westerly winds that bring in more "acidified" waters from the higher latitudes via enhanced meridional Ekman transport and from the subsurface via increased vertical mixing. Our observations support climatic modulation of ocean acidification superimposed on the effect of increasing atmospheric CO2.