3 Seasonal and Intra-Seasonal Variability of Chlorophyll-a in the North Pacific: Model and Satellite data

• Main Authors: Yoshikazu Sasai, Kosei Sasaoka, Hideharu Sasaki, Akio Ishida
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: chlorophyll-a; seasonal variability; high-resolution OGCM; ocean color satellite data; and North Pacific; Pacific; Subarctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.558.8903; http://www.jamstec.go.jp/esc/publication/journal/jes_vol.8/pdf/JES8-21-sasai.pdf

Abstract The seasonal and intra-seasonal variability of chlorophyll-a in the North Pacific is investigate using an ocean color satellite data and a simplified four-component ecosystem model embedded in an eddy-resolving ocean general circulation model. The model captures the realistic seasonal variability of chlorophyll-a distribu-tion associated with the mesoscale eddy activities, sub-mesoscale front variability, western boundary current (Kuroshio), and upwelling. The variability of basin-wide high chlorophyll-a zone between subarctic and subtropi-cal gyres is clearly reproduced in the model. The Kuroshio Extension region exhibits the several time and spatial scale variability. In spring, the westward anticyclonic eddy at the south of Kuroshio Extension deepens the nutri-cline in the subsurface layer and reduces the biological production during the few days. The generated many anti-cyclonic and cyclonic eddies along the Kuroshio affect the ecosystem dynamics. The biological production responds to the uplift and depress of nutricline with the variability of mesoscale physical phenomena.