College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, China.
Guangdong Province Key Laboratory for Coastal Ocean Variation and Disaster Prediction, Guangdong Ocean University, Zhanjiang, China.
PLoS One. 2020 Feb 11;15(2):e0228220. doi: 10.1371/journal.pone.0228220. eCollection 2020.
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 δ13C of particulate organic carbon (δ13C-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.
台风经常影响南海，在改变沿海海洋系统方面发挥着重要作用。为了确定在台风期间哪个过程对沿海海洋区物质输运的影响最大，在 2017 年 6 月两次 Merbok 台风前后的航次中，测量了南海北部沿海（NSCS）水层中的海水温度、盐度、营养盐浓度、叶绿素-a、总悬浮物质和颗粒有机碳的δ13C（δ13C-POC）。结果表明，两个时期的所有参数都发生了显著变化。在台风前，营养盐和理化参数的分层，加上近岸地区水层中高营养盐浓度、高温和低盐度，表明近岸地区受到了源自我们研究区附近沿海城市的河水稀释水的影响。在近海地区，矿化作用可能是底层水中高营养盐浓度的原因。然而，在台风过后，近岸区整个水层中营养盐的分层不太明显，分布更加均匀。在上层水中，营养盐浓度显著增加，温度显著下降。这些结果表明，台风引起的增强垂直混合是改变南海北部沿海营养盐分布模式的主要过程。
