Linkage of the physical environments in the northern Antarctic Peninsula region to the Southern Annular Mode and the implications for the phytoplankton production

The long-term (almost 20 years) hydrographic and primary production data collected by the U.S. Antarctic Marine Living Resources (AMLR) program during the austral summer near Elephant Island and the South Shetland Islands were combined with satellite observations to assess interannual variability in environmental conditions and production of the northern Antarctic Peninsula (NAP). Correlation analyses show that interannual variability of the region is related to the dominant mode of the Southern Hemisphere extratropical climate variability, the Southern Annular Mode (SAM). Post 2000, significant correlations (r > 0.5, p 0.7, p ≤ 0.01). Significant correlations also exist between chlorophyll concentration and the spring and annual SAM indices (r > 0.6, p ≤ 0.06). The statistical relationship between chlorophyll concentration and SAM is used with the predicted variation of SAM based on CMIP5 models to make projections of biological production change over the next 50 years in the NAP and adjacent areas. With an estimated SAM trend of 0.03 yr−1, in the next 50 years the surface chlorophyll concentration over the NAP and WAP outer shelf and slope will increase by as much as 0.5 mg m−3, and the integrated chlorophyll concentration over the upper 100-m water column will increase in the NAP area by 10 mg m−2 to 50 mg m−2.