In a project with Hugh Ducklow, I have been investigating the seasonal patterns of new and export production off of the Western Antarctic Peninsula (WAP). Simple mass balance considerations require that (at suitably large spatiotemporal scales), new production supported by allochthonous nutrients must be balanced by the export of nitrogen from the ecosystem. This has been simplified, in many cases, to the assumption that phytoplankton nitrate uptake will be balanced by the gravitational flux of particulate nitrogen out of the ecosystem. However, due to temporal (and potentially spatial) mismatches between pulses of new production and export flux, this equivalence has not been conclusively shown. In order to address the temporal decoupling, we set out to measure carbon and nitrogen export (using sediment traps and 234Th:238U disequilibrium) and new production (15NO3- uptake measurements) during the entire austral summer (Oct-Mar) at a site in the WAP off of Palmer Station Antarctica.

The WAP encompasses coastal regions as well as pelagic waters adjacent to the Southern Ocean. It is also one of the most rapidly warming regions on the planet and has seen a drastic decrease in sea ice duration and extent in the northern regions, and hence a region where the ocean-atmosphere interactions are changing. Our project involves two distinctly different components. During austral summer 2012-13, I spent 6 months at Palmer Station maintaining a weekly sampling program to measure export and new production. In conjunction with the Palmer Long-Term Ecological Research (LTER) program, we are also working to maintain a time-series of interannual variability in carbon export (using 234Th:238U disequilibrium) and new production throughout the Palmer LTER study region.

​