Seasonal variability of chlorophyll a fronts in the Luzon Strait based on satellite observations
Keywords:
thermal front, edge-detection, monthly-mean image, wind-driven upwellingAbstract
Fronts are important sources of variability in the South China Sea basin, and they play significant roles in controlling bio-physical interactions in the Luzon Strait. We evaluated seasonality of chlorophyll a (chl-a) fronts in the Luzon Strait (LS) based on satellite observations from September 1997 to October 2007. Monthly-mean chl-a concentration at the front was highest in winter (0.8 mg m−3) and lowest in summer (0.3 mg m−3). Additionally, both the probability of frontal occurrence and the seasonal cycle of the gradient between offshore and nearshore chl-a showed that the chl-a front in the LS was the strongest in winter and weakest in summer. Pseudo wind stress played the most important role in shaping the spatial distribution of chl-a concentration, indicating that wind-driven upwelling is the mechanism involved.
References
AVISO. 2006. “SSALTO/DUACS User Handbook: (M) SLA and (M) ADT Near-Real Time and Delayed Time Products”. France: Ramonville St-Agne.
Blanton, J. O. 1986. Coastal frontal zones as barriers to onshore fluxes of contaminants. Rapp. P. v. Reun. Cons. int. Explor. Mer, 186: 18–30.
Cayula, J.-F. and Cornillon, P. 1992. Edge detection algorithm for SST images. Journal of Atmospheric and Oceanic Technology, 9(1): 67–80.
Cayula, J.-F. and Cornillon, P. 1995. Multi-image edge detection for SST images. Journal of Atmospheric and Oceanic Technology, 12(4): 821–829.
Chang, Y., Shimada, T., Lee, M. A., Sakaida, F. and Kawamura, H. 2006. Wintertime sea surface temperature fronts in the Taiwan Strait. Geophysical Research Letters, 33: L23603
Chen, Y. L.L., Chen, H. Y., Lin, I. I., Lee, M. A. and Chang, J. 2007. Effects of cold eddy on phytoplankton production and assemblages in Luzon Strait bordering the South China Sea. Journal of Oceanography, 63(4): 671–683.
Ducet, N., Le Traon, P. Y. and Reverdin, G. 2000. Global high-resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and-2. Journal of Geophysical Research, 105(C8): 19477–19498.
He, Z. G., Wang, D. and Hu, J. Y. 2002. Features of eddy kinetic energy and variations of upper circulation in the South China Sea. Acta Oceanologica Sinica, 21(2): 305–314. (in Chinese)
Kilpatrick, K. A., Podesta, G. P. and Evans, R. 2001. Overview of the NOAA/NASA Advanced Very High Resolution Radiometer Pathfinder algorithm for sea surface temperature and associated matchup database. Journal of Geophysical Research, 106(C5): 9179–9197.
Legeckis, R., Christopher, W. B. and Chang, P. S. 2002. Geostationary satellites reveal motions of ocean surface fronts. Journal of Marine Systems, 37: 3–15.
Le Traon, P. Y. and Dibarboure, G. 1999. Mesoscale mapping capabilities from multiple-satellite altimeter missions. Journal of Atmospheric and Oceanic Technology, 16(9): 1208–1223.
O’Reilly, J. E. 2000. “Ocean color chlorophyll a algorithms for SeaWiFS, OC2, and OC4: Version 4”. In SeaWiFS Postlaunch Technical Report Series, Edited by: Hooker, S. B. and Firestone, E. R. Vol. 11, SeaWiFS Postlaunch Calibration and Validation Analyses. Part 3., NASA Technical Memorandum, 2000–206892
Qiu, C. H., Wang, D. X., Kawamura, H., Guan, L. and Qin, H. L. 2009. Validation of AVHRR and TMI-derived sea surface temperature in the northern South China Sea. Continental Shelf Research, 29(20): 2358–2366. doi:10.1016/j.csr.2009.10.009
Shen, S., Acker, J., Leptoukh, G., Rui, H., Berrick, S. and Kempler, S. 2006. Observing increased chlorophyll-a in storm wakes for the 2005 Atlantic hurricane season using 8-day data products in Giovanni. Eos, Trans. AGU, 87(36) Joint Assembly Supplement, Abstract OS31A-13
Shimada, T., Sakaida, F., Kawamura, H. and Okumura, T. 2005. Application of an edge detection method to satellite images for distinguishing sea surface temperature fronts near the Japanese coast. Remote Sensing of Environment, 98: 21–34.
Sun, C. X. and Liu, Q. Y. 2011. Double eddy structure of the winter Luzon Cold Eddy based on satellite altimeter data. Journal of Tropical Oceanography, 30(3): 9–15.
Takahashi, W. and Kawamura, H. 2005. Detection method of the Kuroshio front using the satellite-derived Chl-a images. Remote Sensing of Environment, 97: 83–91.
Tang, D. L., Ni, I. H., Kester, D. R. and Müller-Karger, F. E. 1999. Remote sensing observations of winter phytoplankton blooms southwest of the Luzon Strait in the South China Sea. Marine Ecology Progress Series, 191: 43–51.
Wang, D. X., Liu, Y., Qi, Y. Q. and Shi, P. 2001. Seasonal variability of thermal fronts in the northern South China Sea from satellite data. Geophysical Research Letters, 28(20): 3963–3966.
Wentz, F. J., Smith, D. K., Mears, C. A. and Gentemann, C. L. 2001. Advanced algorithms for QuikScat and SeaWinds/AMSR. IEEE 2001 IGARSS Proceedings, 3: 1079–1081.
Yuan, D. L., Han, W. and Hu, D. X. 2006. Surface Kuroshio path in the Luzon Strait area derived from satellite remote sensing data. Journal of Geophysical Research, 111(C111007) doi: 10.1029/2005JC003412
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