A Limited Effect of Sub-Tropical Typhoons on Phytoplankton Dynamics
|Author(s)||Chai Fei1, 2, Wang Yuntao1, Xing Xiaogang1, Yan Yunwei1, Xue Huijie2, 3, Wells Mark2, Boss Emmanuel2|
|Affiliation(s)||1 : State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China
2 : School of Marine Sciences, University of Maine, Orono, ME, 04469, USA
3 : State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
|Source||Biogeosciences (1726-4189) (Copernicus GmbH), 2021 , Vol. 18 , N. 3 , P. 849-859|
|Note||Special issue | Biogeochemistry in the BGC-Argo era: from process studies to ecosystem forecasts (BG/OS inter-journal SI)(BG/OS inter-journal SI) Editor(s): Paolo Lazzari, Katja Fennel, Giorgio Dall'Olmo, Alexandre Mignot, and Stefano Ciavatta|
Typhoons are assumed to stimulate ocean primary production through the upward mixing of nutrients into the surface ocean, based largely on observations of increased surface chlorophyll concentrations following the passage of typhoons. This surface chlorophyll enhancement, seen on occasion by satellites, more often is undetected due to intense cloud coverage. Daily data from a BGC-Argo profiling float revealed the upper-ocean response to Typhoon Trami in the Northwest Pacific Ocean. Temperature and chlorophyll changed rapidly, with a significant drop in sea surface temperature and surge in surface chlorophyll associated with strong vertical mixing, which was only partially captured by satellite observations. However, no net increase in vertically integrated chlorophyll was observed during Typhoon Trami or in its wake. Contrary to the prevailing dogma, the results show that typhoons likely have limited effect on net ocean primary production. Observed surface chlorophyll enhancements during and immediately following typhoons in tropical and subtropical waters are more likely associated with surface entrainment of deep chlorophyll maxima. Moreover, the findings demonstrate that remote sensing data alone can overestimate the impact of storms on primary production in all oceans. Full understanding of the impact of storms on upper ocean productivity can only be achieved with ocean observing robots dedicated to high-resolution temporal sampling in the path of storms.