High-Resolution Simulation of Sea Ice and circulation in the West Antarctic Peninsula (WAP)

Cristina Schultz, Woods Hole Oceanographic Inst, Woods Hole, MA, United States and Scott C Doney, University of Virginia, Department of Environmental Sciences, Charlottesville, VA, United States
Over the last decades, the West Antarctic Peninsula (WAP) has undergone physical and ecological changes at a rapid pace, with winter air temperatures warming up to 4.8 times the global average rate. The effects of this warming can be felt in the ecosystem; with changes in the chlorophyll patterns and a poleward shift of ice dependent species. These fluctuations are associated with the sea ice cover in the region, which influences the upper ocean mixed layer depth, heat exchanges and local circulation. Recent research has found a consistent trend of a shortening in the sea ice season in the WAP, associated with changes in the wind pattern. The mechanisms behind these drastic climate changes are not fully understood and have been investigated by the Palmer-LTER (Long Term Ecological Research) over the last two decades. In this context, numerical modeling is a powerful tool, given the seasonal and sea ice constraints on data acquisition in the region. A high-resolution circulation model, coupled to a sea ice model, was implemented in the WAP to simulate the sea ice advance and retreat, and reproduce the annual cycle of sea ice and mixed layer depth in different climate variability scenarios. A successful sea ice model with high vertical and horizontal resolution is a necessary first step towards the implementation of a biogeochemical model that could allow a better understanding of the underlying water chemistry changes behind such drastic ecosystem shifts.