A preliminary study of the variation of phytoplankton absorption coefficients in the northern South China Sea
A preliminary study of the variation of phytoplankton absorption coefficients in the northern South China Sea作者机构:State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China Department of Oceanography Xiamen University Xiamen 361005 China Naval Research Lab Code 7333 Stennis Space Center MS 39529 USA
出 版 物:《Acta Oceanologica Sinica》 (海洋学报(英文版))
年 卷 期:2009年第28卷第5期
页 面:17-29页
核心收录:
学科分类:083002[工学-环境工程] 0830[工学-环境科学与工程(可授工学、理学、农学学位)] 081504[工学-水利水电工程] 08[工学] 0815[工学-水利工程]
基 金:The National Basic Research Program of China under contract Nos 2009CB421200, 2009CB421201 the National Natural Science Foundation of China under contract No40821063 High-Tech R&D Program of China under contract Nos2006AA09A302 and 2008AA09Z108
主 题:phytoplankton absorption coefficient variation picoprokaryotes parameterization South China Sea
摘 要:The temporal and spatial variabilities of phytoplankton absorption coefficients (a ph (λ)) and their relationships with physical processes in the northern South China Sea were examined, based on in situ data collected from two cruise surveys during May 14 to 25, 2001 and November 2 to 21, 2002. Significant changes in the surface water in a ph values and B/R ratios (a ph (440)/a ph (675)) were observed in May, which were caused by a phytoplankton bloom on the inner shelf stimulated by a large river plume due to heavy precipitation. This is consistent with the observed one order of magnitude elevation of chlorophyll a and a shift from a pico/nano dominated phytoplankton community to one dominated by micro-algae. Enhanced vertical mixing due to strengthened northeast monsoon in November has been observed to result in higher surface a ph (675) (0.002–0.006 m-1 higher) and less pronounced subsurface maximum on the outer shelf/slope in November as compared with that in May. Measurements of a ph and B/R ratios from three transects in November revealed a highest surface a ph (675) immediately outside the mouth of the Zhujiang (Pearl) River Estuary, whereas lower a ph (675) and higher B/R ratios were featured in the outer shelf/slope waters, demonstrating the respective influence of the Zhujiang River plume and the oligotrophic water of the South China Sea. The difference in spectral shapes of phytoplankton absorption (measured by B/R ratios and bathochromic shifts) on these three transects infers that picoprocaryotes are the major component of the phytoplankton community on the outer shelf/slope rather than on the inner shelf. A regional tuning of the phytoplankton absorption spectral model (Carder et al., 1999) was attempted, demonstrating a greater spatial variation than temporal variation in the lead parameter a 0 (λ). It was thus implicated that region-based parameterization of ocean color remote sensing algorithms in the northern South China Sea was mandatory.