Boundary Layer Coupling between an Explosive Cyclone and the Gulf Stream during Erica
Final rept. 1 Oct 1990-30 Sep 1991
SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
Pagination or Media Count:
We analyzed oceanographic and atmospheric observations collected during the Experiment on Rapidly Intensifying Cyclones over the Atlantic ERICA for an explosive cyclone event occurring in December 13-14 1989, labeled IOP-2. This explosive cyclone formed over the Gulf Stream Front adjacent to Cape Hatteras it developed independently of upper air baroclinicity and subsequently tracked the Gulf Stream to the east from 74 deg. W to 60 deg. W over the following two-day period. We demonstrate here that a kind of boundary layer coupling existed between the Gulf Stream and the explosive cyclone, with the Gulf Stream Front shown able to alter the boundary layer characteristics of the explosive cyclone and the explosive cyclone, in turn, shown able to alter the frontal character of the Gulf Stream. The effect of this boundary layer coupling, which amounted to a positive feedback between ocean and atmosphere, was to increase the gradient structure of the Gulf Stream by 10-20 from 730-60 deg. W over just a few days. The effect of the boundary layer coupling upon the explosive cyclone is unknown. The atmospheric model employed was that of the planetary boundary layer e.g., Smith, 1988.... Explosive cyclones, ERTCA, Gulf stream.
- Physical and Dynamic Oceanography