HR: 08:30h
AN: OS21D-03    [Abstracts]
TI: The Upper Ocean Heat Budget in Western Boundary Currents
AU: * Kelly, K A
EM: kkelly@apl.washington.edu
AF: Applied Physics Laboratory University of Washington, Box 355640, Seattle, WA 98195-5640 United States
AU: Thompson, L
EM: luanne@ocean.washington.edu
AF: School of Oceanography University of Washington, Box 355351, Seattle, WA 98195 United States
AU: Dickinson, S
EM: suzanne@apl.washington.edu
AF: Applied Physics Laboratory University of Washington, Box 355640, Seattle, WA 98195-5640 United States
AB: In much of the ocean a one-dimensional heat balance exists: the heat storage rate is proportional to the flux of heat into the ocean by the atmosphere. In the regions surrounding energetic midlatitude western boundary currents, there is an annual mean flux of heat out of the ocean, which must be balanced instead by a mean advection of heat into the region. A study of this balance and its low-frequency variations, which affects the oceanic transport of heat from the equator to the poles, requires accurate ocean currents, ocean vector winds, and air-sea heat fluxes. Many of the required fields can be estimated from satellite observations. The largest component of the ocean currents, the geostrophic component, can be derived from measurements of sea level, made possible in the last decade by the radar altimeter measurements beginning in 1992. An additional component of the ocean currents, the Ekman transport, can be estimated from maps of wind vectors. The most accurate and highest resolution winds are from the radar scatterometer SeaWinds on QuikSCAT, beginning in 1999. Air-sea fluxes, although improving in part owing to new satellite measurements, are still somewhat problematic. In the altimeter data we see large interannual variations in the structure and strength of the western boundary currents. To understand the implications of these changes for ocean heat transport, we combine the satellite observations with a simple upper-ocean thermodynamic model to model temperature and heat advection. The vertically integrated heat budgets for both the western North Atlantic (Gulf Stream region) and the western North Pacific (Kuroshio Extension region) show that changes in the heat stored in the upper ocean are the result of both air-sea fluxes and currents, but with currents being more important. Coarse-resolution climate models suggest that a strengthening of midlatitude western boundary currents should increase oceanic heat transport from the equator to the high latitudes. However, the midlatitude heat budgets show substantial changes in the amount of local heat storage, which may decrease or delay the transport of heat to high latitudes. A heat budget analysis which spans the subtropical and subpolar gyres is needed to examine this issue.
DE: 4262 Ocean observing systems
DE: 4275 Remote sensing and electromagnetic processes (0689, 2487, 3285, 4455, 6934)
DE: 4513 Decadal ocean variability (1616, 1635, 3305, 4215)
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005