The variability of front and chlorophyll-a and their relationship in the basin of the South China Sea
Abstract
Satellite observations from 2002 to 2017 were used to investigate the spatial distribution and temporal variability of front and chlorophyll-a (Chl-a) in the South China Sea (SCS). Large frontal activities and high levels of Chl-a were mostly found near the coasts of China and Vietnam, with a significantly increasing trend. Large seasonal variability was found in the northern SCS, with fronts and Chl-a reaching the maximum in winter and minimum in summer, while the seasonal variability of them to the southeast of Vietnam peaked in summer. The monsoon winds and sea surface temperatures were the most important determinants impacting the distribution and variability of front and Chl-a along with other influential environmental drivers, e.g., wind stress curl, monsoon, and sea level anomalies. High correlation coefficients for the seasonal variability between Chl-a and other factors were found in a majority of the SCS, especially in the northern and central parts. The coefficients of wind and Chl-a to the southeast of Vietnam were not valid at seasonal scales, but Chl-a and other factors were significantly correlated at the fields of monthly anomalies. This observation occurred because the nutrient supply was mainly determined by local dynamics, e.g., wind-induced coastal upwelling and offshore transport. The interannual variability indicated low levels of fronts and Chl-a southeast of Vietnam during El Niño years because of the weakened southwest monsoon. The study offered the first comprehensive description of front and Chl-a in the SCS at seasonal, anomalous, and interannual variability scales and an analysis of the potential contributing dynamical processes.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMOS31B..11W
- Keywords:
-
- 4813 Ecological prediction;
- OCEANOGRAPHY: BIOLOGICAL;
- 4815 Ecosystems;
- structure;
- dynamics;
- and modeling;
- OCEANOGRAPHY: BIOLOGICAL;
- 4264 Ocean optics;
- OCEANOGRAPHY: GENERAL;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL