scholarly journals Tropical Pacific Ocean response to observed winds in a layered general circulation model

1992 ◽  
Vol 97 (C5) ◽  
pp. 7317 ◽  
Author(s):  
Arthur J. Miller ◽  
Josef M. Oberhuber ◽  
Nicholas E. Graham ◽  
Tim P. Barnett
Keyword(s):  
Pacific Ocean ◽  
General Circulation Model ◽  
General Circulation ◽  
Circulation Model ◽  
Tropical Pacific ◽  
Tropical Pacific Ocean ◽  
Ocean Response

Intraseasonal Variability of the Surface Zonal Currents in the Western Tropical Pacific Ocean: Characteristics and Mechanisms

2016 ◽  
Vol 46 (12) ◽  
pp. 3639-3660 ◽  
Author(s):  
Fan Wang ◽  
Yuanlong Li ◽  
Jianing Wang
Keyword(s):  
Pacific Ocean ◽  
Ocean Circulation ◽  
General Circulation ◽  
Intraseasonal Variability ◽  
Circulation Model ◽  
Tropical Pacific ◽  
North Equatorial Current ◽  
Tropical Pacific Ocean ◽  
Western Tropical Pacific ◽  
Equatorial Current

AbstractThe surface circulation of the tropical Pacific Ocean is characterized by alternating zonal currents, such as the North Equatorial Current (NEC), North Equatorial Countercurrent (NECC), South Equatorial Current (SEC), and South Equatorial Countercurrent (SECC). In situ measurements of subsurface moorings and satellite observations reveal pronounced intraseasonal variability (ISV; 20–90 days) of these zonal currents in the western tropical Pacific Ocean (WTPO). The amplitude of ISV is the largest within the equatorial band exceeding 20 cm s−1 and decreases to ~10 cm s−1 in the NECC band and further to 4–8 cm s−1 in the NEC and SECC. The ISV power generally increases from high frequencies to low frequencies and exhibits a peak at 50–60 days in the NECC, SEC, and SECC. These variations are faithfully reproduced by an ocean general circulation model (OGCM) forced by satellite winds, and parallel model experiments are performed to gain insights into the underlying mechanisms. It is found that large-scale ISV (>500 km) is primarily caused by atmospheric intraseasonal oscillations (ISOs), such as the Madden–Julian oscillation (MJO), through wind stress forcing. These signals are confined within 10°S–8°N, mainly as baroclinic ocean wave responses to ISO winds. For scales shorter than 200 km, ISV is dominated by ocean internal variabilities with mesoscale structures. They arise from the baroclinic and barotropic instabilities associated with the vertical and horizontal shears of the upper-ocean circulation. The ISV exhibits evident seasonal variation, with larger (smaller) amplitude in boreal winter (summer) in the SEC and SECC.

Tropical-ocean-atmosphere interactions in a coupled model

1989 ◽  
Vol 329 (1604) ◽  
pp. 207-223 ◽  
Keyword(s):  
Pacific Ocean ◽  
General Circulation ◽  
Southern Oscillation ◽  
Heat Budget ◽  
Circulation Model ◽  
Ocean Model ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Tropical Pacific Ocean ◽  
Tropical Ocean

A high-resolution tropical Pacific Ocean model coupled to a medium-resolution atmospheric general circulation model has been integrated for 2 years. A seasonal cycle was included. The atmospheric model when forced with climatological seasonally varying sea surface temperatures simulates the surface stress and net surface heating over the tropical Pacific Ocean to within the uncertainty in the climatological estimates in these quantities. When coupled, however, the models drift into an annually recurring anomalous state, similar in many respects to the El Nino Southern Oscillation observed in the ocean and atmosphere. The model results emphasize the role of off-equatorial anomalies in temperature, atmospheric heating and wind response. Air—sea heat exchange is found to be dominant in determining sea surface temperature changes in these off-equatorial regions. Both cloud and evaporative feedbacks are important in the anomalous surface heat budget.

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