Figure 1
a) Schematic representation of ocean circulation and front patterns along the northern Antarctic Peninsula and its surroundings. Arrows represent the pathways of Circumpolar Deep Water (CDW) intrusions (dashed red;
Dotto et al. 2016DOTTO TS, KERR R, MATA MM & GARCIA CAE. 2016. Multidecadal freshening and lightening in the deep waters of the Bransfield Strait, Antarctica. J Geophys Res Oceans 121(6): 3741-3756. https://doi.org/10.1002/2015JC011228.
https://doi.org/.https://doi.org/10.1002...
,
Ruiz Barlett et al. 2018RUIZ BARLETT EM, PIOLA AR, MATA MM, TOSONOTTO GV & SIERRA ME. 2018. On the temporal variability of intermediate and deep waters in the Western Basin of the Bransfield Strait. Deep Sea Res Part II Top Stud Oceanogr 149(1): 31-46. https://doi.org/10.1016/j.dsr2.2017.12.010.
https://doi.org/.https://doi.org/10.1016...
) and Weddell Sea Dense Shelf Waters advection (continuous purple) entering NAP. Yellow and blue lines represent mean locations of the Southern Antarctic Circumpolar Current Front (SACCF) and the Southern Boundary (SB) of the Antarctic Circumpolar Current, respectively, following
Orsi et al. (1995)ORSI AH, WHITWORTH III T & NOWLIN JR WD. 1995. On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep-Sea Res I Oceanogr Res Pap 42(5): 641-673.. Mesoscale eddies along the Bransfield Strait are shown by blue arrows. Black arrows represent the mean location of the Antarctic Slope Front (ASF;
Heywood et al. 2004HEYWOOD KJ, NAVEIRA GARABATO AC, STEVENS DP & MUENCH RD. 2004. On the fate of the Antarctic Slope Front and the origin of the Weddell Front. J Geophys Res Oceans 109(C6): 1-13.,
Azaneu et al. 2017AZANEU M, HEYWOOD KJ, QUESTE BY & THOMPSON AF. 2017. Variability of the Antarctic slope current system in the Northwestern Weddell sea. J Phys Oceanogr 47: 2977-2997. doi: 10.1175/JPO-D-17-0030.1.). The orange arrow denotes the Bransfield Current System (
Sangrà et al. 2011SANGRà P, GORDO C, HERNáNDEZ-ARENCIBIA M, MARRERO-DíAZ A, RODRíGUEZ-SANTANA A, STEGNER A, MARTíNEZ-MARRERO A, PELEGRí JL & PICHON T. 2011. The Bransfield current system. Deep Sea Res Part I Oceanogr Res Pap 58: 390-402. http://dx.doi.org/10.1016/j.dsr.2011.01.011.
https://doi.org/.https://doi.org/10.1016...
, 2017). Dashed blue lines indicate the Peninsula Front (PF) and the Bransfield Front (BF). The Bransfield Strait basins are indicated as Western Basin (WB), Central Basin (CB) and Eastern Basin (EB). The islands are: Anvers Island (AI), Brabant Island (BI), Clarence Island (CI), Elephant Island (EI), Joinville Island (JI) and South Shetland Islands (SSI).
b) Brazilian High Latitude Oceanography Group (GOAL) biogeochemical stations at NAP over the years 2008–2020. The colored dots represent the biogeochemical stations of the respective scientific projects: SOS-CLIMATE 2008–2010 (blue); POLARCANION 2011, 2013, 2014 (red); NAUTILUS 2015–2019 (yellow), and PROVOCCAR 2020 (green). The SOS-CLIMATE includes measurements of dissolved macronutrients and oxygen, pH, and
pCO
2 continuous survey. Only dissolved macronutrients and oxygen were measured during the POLARCANION survey, with the addition of pH during the 2014 cruise. NAUTILUS and PROVOCCAR surveys encompass the same measurements as SOS-CLIMATE, including sampling of total alkalinity, total dissolved inorganic carbon, and particulate, dissolved and total organic carbon. Phytoplankton pigments and functional groups were measured during all cruises. NAUTILUS 2016 and 2019 includes
pCO
2 continuous survey. The GOAL biogeochemical dataset is provided by request.