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arXiv · 1004.2329

Strong enhancement of chlorophyll a concentration by a weak typhoon

Liang SUN·Yuan-Jian Yang·Tao Xian·Zhu-min Lu·Yun-Fei Fu
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Abstract

Recent studies demonstrate that chlorophyll a (chl a) concentrations in the surface ocean can be significantly enhanced due to typhoons. The present study investigated chl a concentrations in the middle of the South China Sea (SCS) from 1997-2007. Only the Category1 (minimal) Typhoon Hagibis (2007) had a notable effect on the chl a concentrations. Typhoon Hagibis had a strong upwelling potential due to its location near the equator, and the forcing time of the typhoon (>82 h) was much longer than the geostrophic adjustment time (~63 h). The higher upwelling velocity and the longer forcing time increased the depth of the mixed-layer, which consequently induced a strong phytoplankton bloom that accounted for about 30% of the total annual chl a concentration in the middle of the SCS. The implication is that the forcing time of a typhoon should be long enough to establish a strong upwelling and consequently for the induction of significant upper ocean responses.

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Liang SUN, Yuan-Jian Yang, Tao Xian, Zhu-min Lu, Yun-Fei Fu. 2010-04-14. Strong enhancement of chlorophyll a concentration by a weak typhoon. https://doi.org/10.3354/meps08477

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