Remote sensing observations of phytoplankton increases triggered by successive typhoons

Abstract

Phytoplankton blooms in the Western North Pacific, triggered by two successive typhoons with different intensities and translation speeds under different pre-existing oceanic conditions, were observed and analyzed using remotely sensed chlorophyll-a (Chl-a), sea surface temperature (SST), and sea surface height anomaly (SSHA) data, as well as typhoon parameters and CTD (conductivity, temperature, and depth) profiles. Typhoon Sinlaku, with relatively weaker intensity and slower translation speed, induced a stronger phytoplankton bloom than Jangmi with stronger intensity and faster translation speed (Chl-a>0.18 mg·m^‒3 versus Chl-a<0.15 mg·m^‒3) east of Taiwan Island. Translation speed may be one of the important mechanisms that affect phytoplankton blooms in the study area. Pre-existing cyclonic circulations provided a relatively unstable thermodynamic structure for Sinlaku, and therefore cold water with rich nutrients could be brought up easily. The mixed-layer deepening caused by Typhoon Sinlaku, which occurred first, could have triggered an unfavorable condition for the phytoplankton bloom induced by Typhoon Jangmi which followed afterwards. The sea surface temperature cooling by Jangmi was suppressed due to the presence of the thick upper-ocean mixed-layer, which prevented the deeper cold water from being entrained into the upper-ocean mixed layer, leading to a weaker phytoplankton augment. The present study suggests that both wind (including typhoon translation speed and intensity) and pre-existing conditions (e.g., mixed-layer depths, eddies, and nutrients) play important roles in the strong phytoplankton bloom, and are responsible for the stronger phytoplankton bloom after Sinlaku’s passage than that after Jangmi’s passage. A new typhoon-influencing parameter is introduced that combines the effects of the typhoon forcing (including the typhoon intensity and translation speed) and the oceanic pre-condition. This parameter shows that the forcing effect of Sinlaku was stronger than that of Jangmi.

Keywords

typhoon / mixed-layer depth / phytoplankton bloom / Northwest Pacific Ocean / upwelling

References

[1] Babin S M, Carton J A, Dickey T D, Wiggert J D (2004). Satellite evidence of hurricane induced phytoplankton blooms in an oceanic desert. J Geophys Res, 109(C3): 1978–2012

[2] Chen C T A, Liu C T, Chuang W S, Yang Y J, Shiah F K, Tang T Y, Chung S W (2003). Enhanced buoyancy and hence upwelling of subsurface Kuroshio waters after a typhoon in the southern East China Sea. J Mar Syst, 42(1–2): 65–79

[3] Furuya K (1990). Subsurface chlorophyll maximum in the tropical and subtropical western Pacific Ocean: vertical profiles of phytoplankton biomass and its relationship with chlorophylla and particulate organic carbon. Mar Biol, 107(3): 529–539

[4] Gong X, Shi J, Gao H W (2012). Subsurface chlorophyll maximum in ocean: its characteristics and influencing factors. Adv Earth Sci, 27(5): 539–548 (in Chinese)

[5] Gong X, Shi J, Gao H W, Yao X H (2015). Steady-state solutions for subsurface chlorophyll maximum in stratified water columns with a bell-shaped vertical profile of chlorophyll. Biogeosciences, 12(4): 905–919

[6] Hu J Y, Hiroshi K (2004). Detection of cyclonic eddy generated by looping tropical cyclone in the northern South China Sea: a case study. Acta Oceanol Sin, 23(2), 213–224

[7] Lin I I, Wu C C, Emanuel K A, Lee I H, Wu C R, Pun I F (2005). The interaction of Super typhoon Maemi (2003) with a warm ocean eddy. Mon Weather Rev, 133(9): 2635–2649

[8] Lin I, Liu W T, Wu C C, Wong G T F, Hu C, Chen Z, Liang W D, Yang Y, Liu K K (2003). New evidence for enhanced ocean primary production triggered by tropical cyclone. Geophys Res Lett, 30(13)

[9] Liu G Q, He Y J, Shen H, Qiu Z F (2010). Submesoscale activity over the shelf of the northern South China Sea in summer: simulation with an embedded model. Chinese Journal of Oceanology and Limnology, 28: 1073–1079

[10] Lü H, He Y J, Shen H, Cui L M, Dou C E (2010). A new method for the estimation of oceanic mixed-layer depth using shipboard X-band radar images. Chin J Oceanology Limnol, 28(5): 962–967

[11] Pan J Y, Sun Y J (2013). Estimate of ocean mixed layer deepening after a typhoon passage over the south china sea by using satellite data. J Phys Oceanogr, 43(3): 498–506

[12] Price J F (1981). Upper ocean response to a hurricane. J Phys Oceanogr, 11(2): 153–175 doi:10.1175/1520-0485(1981)011<0153:UORTAH>2.0.CO;2

[13] Stewart R H (2008). Introduction to Physical Oceanography. Texas: Texas A & M University, 49–50

[14] Tsai Y, Chern C S, Wang J (2008). The upper ocean response to a moving typhoon. J Oceanogr, 64(1): 115–130

[15] Wei Z X, Fang G H, Choi B H, Fang Y, He Y J (2003). Sea surface height and transport stream function of the South China Sea from a variable-grid global ocean circulation model. Sci China Ser D, 46(2): 139–148

[16] Yentsch C S (1965). Distribution of chlorophyll and phaeophytin in the open ocean. Deep Sea Research and Oceanographic Abstracts, 12(5): 653–666

[17] Zhang B, Perrie W, Zhang J A, Uhlhorn E W, He J Y (2014). High-resolution hurricane vector winds from C-band dual-polarization SAR observations. J Atmos Ocean Technol, 31(2): 272–286

[18] Zhao H, Han G Q, Zhang S W, Wang D X (2013). Two phytoplankton blooms near Luzon Strait generated by lingering Typhoon Parma. J Geophys Res Biogeosci, 118(2): 412–421

[19] Zhao H, Tang D L, Wang Y (2008). Comparison of phytoplankton blooms triggered by two typhoons with different intensities and translation speeds in the South China Sea. Mar Ecol Prog Ser, 365: 57–65

[20] Zheng G M, Tang D L (2007). Offshore and nearshore chlorophyll increases induced by typhoon winds and subsequent terrestrial rainwater runoff. Mar Ecol Prog Ser, 333: 61–74

[21] Zheng Z W, Ho C R, Kuo N J (2008). Importance of pre-existing oceanic conditions to upper ocean response induced by Super Typhoon Hai-Tang. Geophys Res Lett, 35(20): L20603

[22] Zheng Z W, Ho C R, Zheng Q, Lo Y T, Kuo N J, Gopalakrishnan G (2010). Effects of preexisting cyclonic eddies on upper ocean responses to Category 5 typhoons in the western North Pacific.  J Geophys Res (1978–2012), 115(C9)

Acknowledgements

The present research is supported by 1) the Foundation for Distinguished Young Teacher in Higher Education of Guangdong (YQ2013092), 2) the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA11020305, CDA11010301), 3) Project of Enhancing School With Innovation of Guangdong Ocean University, and 4) the National Natural Science Foundation of China (Grant Nos. 41376125, 41006070, and 41376035). This work is also supported by the General Research Fund of Hong Kong Research Grants Council (RGC) under grants CUHK 402912 and 403113, the Hong Kong Innovation and Technology Fund under the grants of ITS/321/13, and the direct grants of the Chinese University of Hong Kong. We thank GlobColor’s Working Group for providing merged Chlorophyll-a data, Remote Sensing Systems for TMI-AMSRE sea-surface temperature and QuikScat wind vector data, the Colorado Center for Astrodynamics Research (CCAR) Altimeter Data Research Group for sea-level anomaly data. The authors are very grateful to the anonymous reviewers for their valuable comments and suggestions.

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2016 Higher Education Press and Springer-Verlag Berlin Heidelberg