Intense nutrient removal in the remote area off Larsen Ice Shelf (Weddell Sea)

Using Weddell Sea data collected during a cruise with "FS Polarstern" in au stral summer 1992/1993, depletions of nutrients and TCO2 in the summer surf ace layer were calculated. The analogous depletion-like properties for temp erature (Heat Storage) and salinity were also computed. The latter properti es are useful to describe the physical conditions over the time period pert inent to the depletions. For different areas a, strong correlation exists o f Heat Storage and nutrient/TCO2 depletions, which is caused by a common fa ctor - the period of light availability. Offshore of the Larsen shelf, an a rea usually inaccessible due to perennial ice cover, high nutrients/TCO2 de pletions are achieved over a short period of time, pointing to a rapidly pr oducing biological system. Primary productivity, calculated from the TCO2 d epletion, amounts to about 100 mg C m(-2) day(-1) for the central Weddell S ea, but 570-1140 mg C m(-2) day(-1) for the offshore Larsen region. These v alues agree fairly well with the open-ocean Antarctic and other coastal are as,respectively.