Analysis of Spatiotemporal Variation in the Chlorophyll-a Concentration in Beibu Gulf
[Objective]This study,investigating the spatiotemporal distribution of surface chlorophyll-a concentration in Beibu Gulf and its influencing factors,aims toprovide scientific evidence for assessing primary productivity and supporting deep-sea aquaculture practices in Beibu Gulf.[Method]Based on monthly satellite remote sensing data of chlorophyll-a concentration,sea surface temperature (SST),rainfall,and reanalysis wind field data from 2003 to 2020,this study employed methods such as empirical orthogonal function (EOF) analysis and wavelet coherence to examine the influence of environmental factors,including SST,rainfall,and wind,on chlorophyll-a concentration in Beibu Gulf.[Result and Conclusion]High levels of chlorophyll-a were predominantly observed near the coastal regions of Beibu Gulf,with lower concentrations in the central offshore areas.The chlorophyll-a concentration in Beibu Gulf exhibited prominent characteristics of interannual variation and reaching its highest level in 2016 with an average concentration of 1.6 mg·m-³,and its lowest level in 2010,with a concentration of 1.1 mg·m-³.The average chlorophyll-a concentration in Beibu Gulf was highest in winter and lowest in spring.In the southern sea area of Weizhou Island,the average chlorophyll-a concentration was highest in winter and lowest in summer.In the Red River estuary region,the chlorophyll-a concentration was higher in summer and autumn than in spring and winter.On the east side of the Annamese Cordillera,the average chlorophyll-a concentration was highest in autumn and lowest in spring.The chlorophyll-a concentration in Beibu Gulf was lowest in May and highest in December.Sea surface temperature,rainfall,and sea surface wind were the primary factors influencing the spatial and temporal distribution of chlorophyll-a concentration in Beibu Gulf.In the central and eastern regions of Beibu Gulf,there existed a significant negative correlation between sea surface temperature and chlorophyll-a concentration (P<0.05,r<-0.8).In the western area of Beibu Gulf,chlorophyll-a concentration was significantly influenced by rainfall.Increased rainfall led to an augmented runoff,resulting in a higher influx of nutrients into Beibu Gulf,higher chlorophyll-a levels in the Red River estuary area during summer and autumn,and chlorophyll-a concentration peaks in the eastern coast of the Annamese Cordillera during autumn.The wind speed was significantly positively correlated with chlorophyll-a concentration in Beibu Gulf (P<0.01,r=0.4).
Beibu Gulfchlorophyll-a concentrationempirical orthogonal function analysisrainfall
万方数据
维普
