Decadal variability of chlorophyll α in the South China Sea: a possible mechanism  

作　　者：刘汾汾 陈楚群 詹海刚 

机构地区：[1]State Key Laboratory of Oceanography in the Tropics,South China Sea Institute of Oceanology,Chinese Academy of Sciences [2]Graduate University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2012年第6期1054-1062,共9页中国海洋湖沼学报（英文版）

基　　金：Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. KZCX1-YW-12-01, KZCX2-YW-Q11-02);the National Natural Science Foundation of China (Nos. 41006111, 40976106);the Project from Guangzhou City for the Pearl River New Star on Science and Technology (No. 2011J2200022)

摘　　要：Four climatologies on a monthly scale (January, April, May and November) of chlorophyll a within the South China Sea (SCS) were calculated using a Coastal Zone Color Scanner (CZCS) (1979-1983) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) (1998-2002). We analyzed decadal variability of chlorophyll a by comparing the products of the two observation periods. The relationships of variability in chlorophyll a with sea surface wind speed (SSW), sea surface temperature (SST), wind stress (WS), and mixed layer depth (MLD) were determined. The results indicate that there is obvious chlorophyll a decadal variability in the SCS. The decadal chlorophyll a presents distinct seasonal variability in characteristics, which may be as a result of various different dynamic processes. The negative chlorophyll a concentration anomaly in January was associated with the warming of SST and a shallower MLD. Generally, there were higher chlorophyll a concentrations in spring during the SeaWiFS period compared with the CZCS period. However, the chlorophyll a concentration exhibits some regional differences during this season, leading to an explanation being difficult. The deepened MLD may have contributed to the positive chlorophyll a concentration anomalies from the northwestern Luzon Island to the northeastern region of Vietnam during April and May. The increases of chlorophyll a concentration in northwestern Borneo during May may be because the stronger SSW and higher WS produce a deeper mixed layer and convective mixing, leading to high levels of nutrient concentrations. The higher chlorophyll a off southeastern Vietnam may be associated with the advective transport of the colder water extending from the Karimata Strait to southeastern Vietnam.Four climatologies on a monthly scale （January, April, May and November） of chlorophyll a within the South China Sea （SCS） were calculated using a Coastal Zone Color Scanner （CZCS） （1979-1983） and the Sea-viewing Wide Field-of-view Sensor （SeaWiFS） （1998-2002）. We analyzed decadal variability of chlorophyll a by comparing the products of the two observation periods. The relationships of variability in chlorophyll a with sea surface wind speed （SSW）, sea surface temperature （SST）, wind stress （WS）, and mixed layer depth （MLD） were determined. The results indicate that there is obvious chlorophyll a decadal variability in the SCS. The decadal chlorophyll a presents distinct seasonal variability in characteristics, which may be as a result of various different dynamic processes. The negative chlorophyll a concentration anomaly in January was associated with the warming of SST and a shallower MLD. Generally, there were higher chlorophyll a concentrations in spring during the SeaWiFS period compared with the CZCS period. However, the chlorophyll a concentration exhibits some regional differences during this season, leading to an explanation being difficult. The deepened MLD may have contributed to the positive chlorophyll a concentration anomalies from the northwestern Luzon Island to the northeastern region of Vietnam during April and May. The increases of chlorophyll a concentration in northwestern Borneo during May may be because the stronger SSW and higher WS produce a deeper mixed layer and convective mixing, leading to high levels of nutrient concentrations. The higher chlorophyll a off southeastern Vietnam may be associated with the advective transport of the colder water extending from the Karimata Strait to southeastern Vietnam.

关 键 词：South China Sea （SCS） decadal variability chlorophyll a 

分 类 号：P734[天文地球—海洋化学]