Air–Sea Interaction during an Extreme Cold Air Outbreak from the Eastern Coast of the United States

Abstract

Abstract The area east of the coast of North Carolina chosen for enhanced observation during the Genesis of Atlantic Lows Experiment (GALE) has one of the highest average wintertime energy transfers from ocean to atmosphere on earth. A substantial part of this transfer occurs in the aftermath of winter storms as cold, dry air flows off of the continent over the warm Gulf Stream. We report on an aircraft investigation of boundary layer mean and turbulent structure and evaluate the Lagrangian budgets of temperature and moisture in the subcloud layer following a streamline during an extreme cold air outbreak. The maximum sea-air temperature difference was 23 K. Two aircraft were used: the NCAR Electra, which measured turbulent fluxes and investigated subcloud layer conditions, while the NASA Electra, using a radar, measured the height of cloud tops. A stratocumulus overcast was found from about 60 km offshore to the Gulf Stream core with cloud top rising downstream. East of the Gulf Stream cumulus congestus ...