Phytoplankton response to interannual climate variability has an important regulatory effect on the regional marine ecological environment and carbon cycle. In this study, we focused on the phytoplankton response in the upwelling region of the Sulu Ridge to the El Niño-Southern Oscillation (ENSO) based on monthly remote sensing chlorophyll-a concentration (Chl-a) and physical parameters from various sources from September 1997 to December 2017. We selected two El Niño events in 1997/1998 and 2015/2016 and two La Niña events in 1998/1999 and 2010/2011 to examine the response of Chl-a to ENSO events in this region. Results showed that El Niño and La Niña could enhance and inhibit the growth of phytoplankton in the Sulu Ridge in winter, respectively. For other seasons, the influence of ENSO on the Chl-a was inconsistent. Specifically, during El Niño events, the largest Chl-a increases occurred in winter, and the low sea surface temperature (SST) center appeared northwest of Sulu Ridge. The significant decrease of SST (∼1.5 °C) during El Niño events in winter in the northeastern Sulu Ridge was mainly caused by the increase in Ekman transport (ET) and Ekman pumping velocity (EPV), which brought nutrient-rich subsurface water to the surface layer through the thin barrier layer and enhanced Chl-a. During La Niña events, the SST was higher (∼0.8 °C) than the average and the high SST center generally appeared in the middle of the Sulu Ridge with the east-west direction in winter, which was resulted from the intensification of barrier layer thickness (BLT) and the decrease of ET, thus reducing the Chl-a. The different responses to El Niño and La Niña events indicate the high sensitivity of Chl-a in this region to the ENSO.

浮游植物对年际气候变化的响应对区域海洋生态环境和碳循环具有重要的调节作用。在这项研究中，我们基于9月的月度遥感叶绿素a浓度（Chl- a）和来自各种来源的物理参数，着重研究了苏禄岭上升流地区浮游植物对厄尔尼诺-南方涛动（ENSO）的响应1997年至2017年12月，我们选择在1997/1998和两个厄尔尼诺事件2016分之2015和1998/1999和2010/2011 2个拉尼娜事件检查Chl-的响应一个到该地区的ENSO事件。结果表明，厄尔尼诺和拉尼娜分别在冬季可增强和抑制苏禄岭浮游植物的生长。对于其他季节，ENSO对Chl-影响一个是不一致的。具体而言，在厄尔尼诺事件，最大的Chl-一个增加发生在冬季，而低海表温度（SST）中心出现西北苏禄海岭。苏鲁山东北部冬季在冬季厄尔尼诺事件期间，SST（〜1.5°C）显着下降，主要是由于Ekman运移（ET）和Ekman抽水速度（EPV）的增加，这使营养丰富的地下水进入了通过薄阻挡层的表面层和增强Chl-一个。在拉尼娜事件期间，SST高于平均水平（约0.8°C），并且较高的SST中心通常出现在苏鲁山脊的中部，冬季为东西向，这是由于屏障层的增强厚度（BLT）和ET的降低，从而降低Chla- a。厄尔尼诺和拉尼娜事件的不同反应表明Chl-的高灵敏度一个在该区域中的ENSO。