Typhoon Merbok induced upwelling impact on material transport in the coastal northern South China Sea

Abstract

Typhoons frequently affect the South China Sea (SCS), playing an important role in changing the coastal marine system. To determine which process has the greatest impact on material transport in the coastal marine area during a typhoon, the sea temperature, salinity, concentration of nutrients, chlorophyll-a, total suspended matter, and δ 13 C of particulate organic carbon (δ 13 C-POC) in the water column of coastal Northern SCS (NSCS) were measured during two cruises in June 2017, in the pre-and post-typhoon Merbok periods. The results show that all parameters changed significantly between the two periods. During the pre-typhoon period, stratification of nutrients and physicochemical parameters, combined to high nutrient concentrations, high temperature, and low salinity in the water column of the nearshore area, suggests that the nearshore area is influenced by the river diluted water originated in the coastal cities adjacent to our study area. In the offshore area, mineralization may be responsible for the high nutrient concentration in the bottom water. However, during the post-typhoon, the stratification of nutrients is less significant and their distribution more homogenous in the whole water column of the nearshore area. In the upper water, the nutrient concentration increased and the temperature decreased significantly. These results suggest that the enhanced vertical mixing induced by the typhoon was the dominant process in changing the nutrient distribution pattern in the coastal NSCS.

Typhoon Effects on the Vertical Chlorophyll Distribution on the Northern Shelf of the South China Sea

“…Jiang et al. (2020) suggested that enhanced vertical mixing after a typhoon was the dominant process changing the nutrient distribution in the coastal region of the northern SCS. However, the vertical distribution of phytoplankton in response to the combined influences of typhoons, upwelling, and river discharge still remains unclear.…”

Effects of Typhoon Mujigae on the Biogeochemistry and Ecology of a Semi‐Enclosed Bay in the Northern South China Sea

“…However, typhoon‐induced rain enhances runoff/river discharge, introducing a large amount of terrestrial organic matter and anthropogenic organic matter into coastal and estuarine systems (Chen & Li, 2002; Jiang et al., 2020; Xue et al., 2000). Enhanced discharge can also cause complete flushing, with considerable damage to mariculture activities in coastal and estuarine systems (Herbeck et al., 2011; Peng et al., 2016; Stevens et al., 2006; Yang et al., 2020).…”

Partitioning of carbon export in the upper water column of the oligotrophic South China Sea

“…The dark blue dashed lines denote the paths of typhoon Merbok (sourced from the southeastern part of SCS on June 9 th , 2017, adapted from Jiang et al, 2020) and Mun (sourced from the eastern part of the SCS on July 1 st , 2019, adapted from Sun et al, 2021). At the mega stations, high vertical resolution water samples were taken at a depth interval of 10 m within the Ez.…”