Cyclogenesis Near the Adélie Coast and Influence of the Low-level Wind Regime

by Steinhoff, Daniel Frederick

Cyclone activity in the Adélie Coast region is analyzed using three years (2003-2005) of data from the Antarctic Mesoscale Prediction System (AMPS). "Type I" cyclone development occurs off-shore between 145°E-150°E on the leading edge of a dissipating cyclone to the west near 120°E, primarily as a result of barrier wind formation and favorable upper level support. "Type II" cyclone development occurs adjacent to the coast near 155°E. Type II development exhibits a barotropic structure, and leeside cyclogenesis is common, with near-surface cyclonic vorticity produced by interaction of katabatic winds with the ambient environment. In both categories of development, the low-level wind regime, especially the Adélie Land katabatic wind regime, is found to be a key component of cyclogenesis in the Adélie Coast region, contrary to inferences made in several earlier studies that effects are confined to mesoscale cyclone development.