摘要
Over recent decades,the increasing frequency and intensity of Harmful Algal Blooms(HABs)have resulted in severe environmental impacts worldwide.Understanding the physical drivers of HABs is crucial for understanding their dynamics and mitigating their environmental consequences.This study integrates satellite remote sensing and hydrodynamic modeling to investigate two HAB events and their driving mechanisms in Guangdong coastal waters during February and August 2021.An HAB detection method using Sentinel-3 ocean and land color instrument data based on an improved floating algae index algorithm was developed.The spatiotemporal dynamics of physical drivers were analyzed using a submesoscale permitting regional ocean modeling system hydrodynamic simulation.Both HAB detection results and hydrodynamic simulations were validated against in situ buoy measurements.In coastal area of Jiangmen City,local changes of divergence,impacts from the Zhujiang River(Pearl River)fresh water plume were found to be drivers accounted for long-termed variations of chlorophyll and triggers for HABs,while changes in vertical mixing associated with wind speed regulate the short-termed changes.In coastal area of Shantou City,initiations of HABs were mainly driven by wind-induced coastal upwelling.Distribution,aggregation and elongation of HAB patches were modulated by surface fronts and vortices induced by fresh water plume and complex coastlines.These findings underscore the advantages of integrating satellite remote sensing,3D hydrodynamic modeling,and in situ observations for elucidating the complex physical mechanisms governing HAB dynamics in coastal waters.
基金
The fund from Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2024SP029
the National Natural Science Foundation of China under contract Nos 42176173,42476268,and 42106173
the fund from Beijing Engineering Research Center of Aerial Intelligent Remote Sensing Equipments under contract No.AIRSE20234.
