Analysis of Surface Fluxes in the Marine Atmospheric Boundary Layer in the Vicinity of Rapidly Intensifying Cyclones

Gennaro H. Crescenti Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

Search for other papers by Gennaro H. Crescenti in
Current site
Google Scholar
PubMed
Close
and
Robert A. Weller Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

Search for other papers by Robert A. Weller in
Current site
Google Scholar
PubMed
Close
Full access

Abstract

A mooring with a surface buoy was deployed about 300 km southeast of Nova Scotia during the Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) in an attempt to obtain long-term, high-quality measurements of meteorological and near-surface oceanographic data. The acquired surface data included sea surface temperature, air temperature, relative humidity, barometric pressure, wind velocity, incident solar radiation, and downward longwave radiation. A limited time series of sea temperature and current velocity was gathered from current meters at 20 and 50 m beneath the sea surface.

The surface meteorology was described before, during, and after the passage of three rapidly intensifying cyclones. Estimates of the surface air-sea heat fluxes, computed from bulk aerodynamic formulas, were also examined for these same storms. A simple heat budget was used to estimate the heat loss or gain of the upper ocean against the air-sea heat transfer at the ocean surface. While the total surface heat flux may sometimes exceed 1000 W M−2, the data suggest that the main mechanism for cooling the upper-ocean water was principally advective. An examination of the air-sea momentum transfer shows that the atmosphere exerted a significant influence on the upper ocean; persistent westerly winds coming off the North American continent transported surface waters to the south.

Abstract

A mooring with a surface buoy was deployed about 300 km southeast of Nova Scotia during the Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) in an attempt to obtain long-term, high-quality measurements of meteorological and near-surface oceanographic data. The acquired surface data included sea surface temperature, air temperature, relative humidity, barometric pressure, wind velocity, incident solar radiation, and downward longwave radiation. A limited time series of sea temperature and current velocity was gathered from current meters at 20 and 50 m beneath the sea surface.

The surface meteorology was described before, during, and after the passage of three rapidly intensifying cyclones. Estimates of the surface air-sea heat fluxes, computed from bulk aerodynamic formulas, were also examined for these same storms. A simple heat budget was used to estimate the heat loss or gain of the upper ocean against the air-sea heat transfer at the ocean surface. While the total surface heat flux may sometimes exceed 1000 W M−2, the data suggest that the main mechanism for cooling the upper-ocean water was principally advective. An examination of the air-sea momentum transfer shows that the atmosphere exerted a significant influence on the upper ocean; persistent westerly winds coming off the North American continent transported surface waters to the south.

Save