HR: 1400h
AN: A43C-04    [Abstracts]
TI: The barrier layer and its role in maintaining the tropical Atlantic warm pool
AU: * Jang, C
EM: jcj@pod.tamu.edu
AF: Department of Oceanography, 3146 Texas A&M University, College Station, TX 77843, United States
AU: * Jang, C
EM: jcj@pod.tamu.edu
AF: Korea Ocean Research & Development Institute (KORDI), 1270 Sa2-dong, SangRok-gu, Ansan, 426-744, Korea, Republic of
AU: Chang, P
EM: ping@tamu.edu
AF: Department of Oceanography, 3146 Texas A&M University, College Station, TX 77843, United States
AU: Breugem, W
EM: breugem@knmi.nl
AF: Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, 3730 AE De Bilt, Netherlands
AB: In the western tropical Atlantic Ocean, the barrier layer (BL), which is defined as the distance between the bottom of the mixed layer and the bottom of the isothermal layer, is often associated with a temperature inversion. When this occurs, the vertical entrainment brings warmer water from the BL into the mixed layer, causing an increase in the sea surface temperature (SST). We explore the role of this warming mechanism in the maintenance of the western Tropical Atlantic warm pool using the latest Simple Ocean Data Assimilation (SODA) product. During boreal fall and winter, the BL in the northwestern tropical Atlantic reaches a depth of 40 m, due to the combined effects of ITCZ rainfall, Amazon River discharge and the subsurface salinity maximum. An average temperature inversion of 0.1°C is common during these seasons. We estimate that the BL-induced temperature inversion can contribute to a warming of the surface mixed layer at a rate of 0.1°C per month, which accounts for about 30 % of total SST change. This result suggests that in the northwestern tropical Atlantic Ocean the BLs and the associated temperature inversion play an important role in maintaining the warm sea-surface temperature and need to be properly simulated to reduce a cold bias which is common in coupled climate model simulations.
DE: 1620 Climate dynamics (0429, 3309)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly