Response of Sea Surface Temperature to Chlorophyll-a Concentration in the Tropical Pacific:Annual Me

• 作 者: 林鹏飞 刘海龙 俞永强 张学洪
• 机 构: State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,I
• 出 处: Advances in Atmospheric Sciences
• 发表日期: 2011年03期
• 关键词: seasonal equatorial chlorophyll ENSO ocean shallow tropical currents Tropical he

The response of the upper-ocean temperatures and currents in the tropical Pacific to the spatial distribution of chlorophyll-a and its seasonal cycle is investigated using a coupled atmosphere-ocean model and a stand-alone oceanic general circulation model.The spatial distribution of chlorophyll-a significantly influences the mean state of models in the tropical Pacific.The annual mean SST in the eastern equatorial Pacific decreases accompanied by a shallow thermocline and stronger currents because of shallow penetration depth of solar radiation.Equatorial upwelling dominates the heat budget in that region.Atmosphere-ocean interaction processes can further amplify such changes. The seasonal cycle of chlorophyll-a can dramatically change ENSO period in the coupled model.After introducing the seasonal cycle of chlorophyll-a concentration,the peak of the power spectrum becomes broad,and longer periods(>3 years) are found.These changes led to ENSO irregularities in the model. The increasing period is mainly due to the slow speed of Rossby waves,which are caused by the shallow mean thermocline in the northeastern Pacific.

The response of the upper-ocean temperatures and currents in the tropical Pacific to the spatial distribution of chlorophyll-a and its seasonal cycle is investigated using a coupled atmosphere-ocean model and a stand-alone oceanic general circulation model. The spatial distribution of chlorophyll -a significant trends the mean state of models in the tropical Pacific. the annual mean SST in the eastern equatorial Pacific yoy accompanied by a shallow thermocline and stronger due to shallow penetration depth of solar radiation. Equatorial upwelling dominates the heat budget in that region .Atmosphere-ocean interaction processes can further amplify such changes. The seasonal cycle of chlorophyll-a cans dramatically change ENSO period in the coupled model. After introducing the seasonal cycle of chlorophyll-a concentration, the peak of the power spectrum becomes broad, and longer periods (> 3 years) are found.These changes led to ENSO irregularities in the model. The increasin g period is mainly due to the slow speed of Rossby waves, which are caused by the shallow mean thermocline in the northeastern Pacific.