Physical oceanography on board of POLARSTERN (1983-11-22 to 2016-02-14)

Improving Antarctic Bottom Water precursors in NEMO for climate applications

“…In both the Weddell and Ross Seas, opening the cavities decreases sea ice production to the west of the ice shelves, assisting in the partial reduction of the salt bias in these areas linked to polynya activity. By comparing model output with two CTD sections performed across the front of FRIS in 1980 and 1995 (Rohardt et al, 2016;Janout et al, 2021), we see clear evidence of an improvement in the realism of water properties with the opening of the sub-ice shelf cavity. Similarly in the Ross Sea, an anticlockwise sub-ice shelf cavity circulation cell facilitates the spread of HSSW across the continental shelf and ocean-ice shelf interactions create a cold ISW plume to the east of Roosevelt Island.…”

“…For comparison purposes, we have consequently selected CTD data from research cruises that have sampled transects across the front of the ice shelves and e tracted the model data corresponding to the appro imate ship s track using PAGO, a pre-existing tool to analyze gridded ocean datasets (Deshayes et al, 2014). For FRIS we use two CTD sections across the ice shelf front undertaken in 1980 and 1995 on board the RV Polarstern by the Alfred Wegener Institute (Rohardt et al, 2016;Janout et al, 2021). The location of the section selected in NEMO to approximately overlay the CTD transects can be seen as a magenta dotted line in Fig.…”

“…6c and 6i). (Rohardt et al, 2016) and 1995 (Janout et al, 2021). The model output for the corresponding equivalent year and month was extracted for more accurate comparison.…”

“…Figure 6: Validation of properties across the Filchner Ronne Ice Shelf front by comparing closed and open cavity NEMO results with measured values from CTD sections performed in 1980(Rohardt et al, 2016) and 1995(Janout et al, 2021). The model output for the corresponding equivalent year and month was extracted for more accurate comparison.…”