The roles of vertical mixing, solar radiation, and wind stress in a model simulation of the sea surface temperature seasonal cycle in the tropical Pacfic Ocean

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Journal of Geophysical Research

OSTI ID:45823

Chen, D; Busalacchi, A J; Rothstein, L M ^[1]

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1. Rhode Island Univ., Narragansett, RI (United States)

The climatological seasonal cycle of sea surface temperature (SST) in the tropical Pacific is simulated using a newly developed upper ocean model. The roles of vertical mixing, solar radiation, and wind stress are investigated in a hierarchy of numerical experiments with various combinations of vertical mixing algorithms and surface-forcing products. It is found that the large SST annual cycle in the eastern equatorial Pacific is, to a large extent, controlled by the annually varying mixed layer depth which, in turn, is mainly determined by the competing effects of solar radiation and wind forcing. With the application of our hybrid vertical mixing scheme the model-simulated SST annual cycle is much improved in both amplitude and phase as compared to the case of a constant mixed layer depth. Beside the strong effects on vertical mixing, solar radiation is the primary heating term in the surface layer heat budget, and wind forcing influences SST by driving oceanic advective processes that redistribute heat in the upper ocean. For example, the SST seasonal cycle in the western Pacific basically follows the semiannual variation of solar heating, and the cycle in the central equatorial region is significantly affected by the zonal advective heat flux associated with the seasonally reversing South Equatorial Current. It has been shown in our experiments that the amount of heat flux modification needed to eliminate the annual mean SST errors in the model is, on average, no larger than the annual mean uncertainties among the various surface flux products used in this study.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
• OSTI ID: 45823
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: C10 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
54 ENVIRONMENTAL SCIENCES
ANNUAL VARIATIONS
HEAT FLUX
MIXING
PACIFIC OCEAN
SOLAR RADIATION
TEMPERATURE DISTRIBUTION
TROPICAL REGIONS