| In recent years,the concentration of sea surface chlorophyll a has become a research hotspot in coastal environment and disasters,and it is also the key to calculate marine primary productivity.In this paper,combined with multi-source satellite remote sensing data and field observations,the effect of sea surface temperature on chlorophyll concentration is studied,and the relationship between these two factors is detected,in order to monitor the change of chlorophyll concentration with sea surface temperature.The improved DINEOF interpolation method was used to reconstruct the sea surface temperature data and chlorophyll a concentration data by the fusion of MODIS-Aqua and MODIS-Terra’s dataset,during the period of 2003 to 2017.Four sets of data without missing values were obtained.The reconstruction accuracy(RMSE)was 0.58℃(monthly average SST),0.92mgm-3(monthly average Chla),0.73℃(8-day SST)and 1.13 mgm-3(8-day Chla),respectively.The improved interpolation algorithm improves the accuracy of the interpolation algorithm by about 0.2 mg m-3(RMSE).In addition,compared with the measured data,the reconstructed data are more accurate.Compared with the measured data in 2016,the average relative error(MRE)of the 8-Day’s sea surface temperature data is only 3%.In comparison with the Kriging method,the DINOEF is more precise and more efficient.Therefore,reconstructed data performed by DINEOF can be used for analysis.Then,the spatial and temporal distribution characteristics of sea surface temperature and chlorophyll a concentration were investigated by the interpolated reconstructed data.It can be seen that the sea surface temperature shows a fluctuated upward trend in the past 15 years,but the upward trend was not significant.The chlorophyll a concentration also showed an upward trend during this period,and the upward trend passed the M-K significance test at 95%confidence level.The spatial distribution of chlorophyll concentration is southeast-northwest,and the concentration increases from southeast to northwest,while the distribution of SST is contrary to that.The monthly mean sea surface temperature was positive correlated with chlorophyll a concentration in the coastal areas of Jiangsu and Zhejiang provinces,with a correlation coefficient of 0.35 and a maximum of 0.74,which were located in the northern coastal waters of Jiangsu Province.While the correlation between them was negatively correlated in the southeastern waters.The positive and negative correlated sea areas are bounded by the 35-metre contour.It was found that the average sea temperature was 17.97℃ and the average chlorophyll concentration was 3.88 mg/m3 in the positive correlate area.With the rise of SST in spring,the coastal surface water flows eastward,and the subsurface water with rich nutrients turns up,which leads to the increase of chlorophyll concentration.The regression model for highly relevant regions during the period of February to July is y=5.184*exp(-((x-25.18)/22.78)2). |
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