The Spatio-Temporal Variability of Chlorophyll-A and Its Physical Variables in the South Java Sea Shelf
Year: 2021
Type: article
Abstract: The Chlorophyll-a (Chl-a) dynamics in the upwelling system associate with physical variables that accompany it, whether it is a driver or a response to the upwelling process. As an upwelling driver, wind and current could enhance the Chl-a concentration through a process known as wind-driven and current-driven upwelling, respectively. On the other hand, Sea Surface Temperature (SST) and Sea Surface Height Anomaly (SSHA) come as the upwelling response. We examine these four physical variables against the Chl-a dynamics in the South Java Sea shelf using satellite-derived and ocean reanalysis data from 2002 to 2017. Chl-a variability was examined using Empirical Orthogonal Function (EOF) to find spatial and temporal contrasting differences, then relate them to the physical variables. Our result exhibits seasonal patterns in the Chl-a variations, indicating the well-known South Java upwelling system, which is high during the south-east (SE) monsoon and low during the north-west (NW) monsoon. March and September were the two contrasting months shown by the significant differences of Chl-a, alongshore wind stress, SST, and SSHA between the two. The alongshore wind has a significant correlation with the Chl-a at the shelf area in September since wind-driven upwelling during that time. The alongshore bottom stress significantly correlates with the Chl-a at the 109.5˚E, 8˚S in March (wind-driven downwelling periods), indicating an upwelling-favorable current. However, the vertical cross-shelf temperature and alongshore current do not show a current-driven upwelling nor water masses uplift at this point in March. Keywords: chlorophyll-a, physical variables, Empirical Orthogonal Analysis, South Java upwelling.
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
Award: G8295809241
OpenAlex ID: W3195549622