The Seasonal Effect of Coastal Current and Upwelling on the Dynamics of Dissolved Organic Matter in the Northwestern South China Sea DOI

Xuan Lu,

Qibin Lao, Chao Wang

и другие.

Journal of Geophysical Research Oceans, Год журнала: 2024, Номер 129(7)

Опубликована: Июнь 27, 2024

Abstract Previous studies have primarily focused on the impact of human activities coastal dissolved organic matter (DOM) cycles, while neglecting role dynamic processes. This limits our comprehensive understanding processes DOM, particularly in waters affected by multiple In this study, dynamics DOM northwestern South China Sea (SCS) were investigated using DOM‐related parameters and a three end‐member mixing model, which accounted for effects currents upwelling during spring, summer, winter seasons. Our results demonstrated that net addition was predominantly observed nearshore all seasons, owing to strong induced phytoplankton production particle desorption. However, weaker spring winter, removal decomposition western offshore area. observation can be attributed abundance microorganisms increased vertical water winter. Conversely, stronger provided more bio‐refractory limiting its decomposition, whereas stimulated productivity desorption, resulting period. eastern area, primary mechanism eliminating weak or absent upwelling. study revealed is widespread regions SCS facilitate DOM.

Язык: Английский

Using Stable Isotopes and Spectral Properties of Particulate and Dissolved Organic Matter to Quantify Typhoon‐Induced Organic Matter Decomposition DOI
Xuan Lü, Qibin Lao,

Chunqing Chen

и другие.

Journal of Geophysical Research Oceans, Год журнала: 2024, Номер 129(2)

Опубликована: Фев. 1, 2024

Abstract Typhoons exert a profound impact on marine biogeochemical processes, with organic matter (OM) decomposition serving as key process in coastal waters after typhoons. Despite its significance, the specific contributions of particulate (POM) and dissolved (DOM) to OM triggered by typhoons remains unclear. In this study, stable isotopes POM spectral properties DOM were investigated before Typhoon “Barija" Zhanjiang Bay, northwestern South China Sea. The typhoon‐induced intrusion high‐salinity seawater from lower bay upper bay, driven external clockwise wind stress, led formation an ocean front middle during typhoon. Notably, induced typhoon (72%) significantly surpassed that (5%), attributed barrier effect increased vertical mixing bay. contrast, removed only 29% net addition occurred due phytoplankton growth decomposition. More importantly, despite overall larger water column, inventory (20.19 g m −2 ) exceeded (16.08 ). Overall, our study suggests is more critical than typhoons, primarily influenced mixing. These findings contribute clearer understanding post‐typhoon dynamics waters.

Язык: Английский

Процитировано

7
Interannual variation of coastal upwelling around Hainan Island DOI Creative Commons
Junying Zhu,

Quanyi Zhou,

Qianqing Zhou

и другие.

Frontiers in Marine Science, Год журнала: 2023, Номер 10

Опубликована: Янв. 24, 2023

Coastal upwelling around Hainan Island has a significant impact on the physical environment, ecological and fishery resources of surrounding waters. Based satellite-observed sea surface temperature (SST) from 2003 to 2021, this study analyzed interannual variations SST influence forcing them, with special attention regions in Qiongdong Qiongxi. The results show that can identify three located west (WS), east (ES), northeast (NES) sides Island. SSTs WS, ES, NES showed warming trends 0.045 °C/y, 0.010 0.036 respectively. range low-temperature water gradually shrunk over past two decades, shrinkage trend was more prominent WS region than ES regions. Both EOF analysis difference between non-upwelling suggests becomes stronger after 2013. However, it seems not compete overall northwest area South China Sea. were affected by local wind stress curl summer. Except for curl, are influenced stratification associated precipitation direction, especially 2018. In addition, variation is closely related bottom cold central Gulf Tonkin, which preserved previous winter atmospheric conditions. These helpful understanding ecosystem

Язык: Английский

Процитировано

11
Remote sensing estimation of δ15NPN in the Zhanjiang Bay using Sentinel-3 OLCI data based on machine learning algorithm DOI Creative Commons
Guo Yu,

Yafeng Zhong,

Dongyang Fu

и другие.

Frontiers in Marine Science, Год журнала: 2024, Номер 11

Опубликована: Май 14, 2024

The particulate nitrogen (PN) isotopic composition (δ 15 N PN ) plays an important role in quantifying the contribution rate of organic matter sources and indicating water environmental pollution. Estimation δ from satellite images can provide significant spatiotemporal continuous data for cycling ecological environment governance. Here, order to fully understand dynamic , we have developed a machine learning algorithm retrieving . This is successful case combining isotopes remote sensing technology. Based on field observation Zhanjiang Bay May September 2016, three retrieval models (Back Propagation Neural Network, Random Forest Multiple Linear Regression) were constructed using optical indicators composed situ reflectance as input variable output variable. Through comparative analysis, it was found that Back Network (BPNN) model had better performance. BPNN applied quasi-synchronous Ocean Land Color Imager (OLCI) onboard Sentinel-3. determination coefficient (R 2 ), root mean square error (RMSE) absolute percentage (MAPE) satellite-ground matching point based 0.63, 1.63‰, 20.10%, respectively. From results, be inferred value good consistency with measured In addition, independent datasets used validate model, which showed accuracy retrieval, effective has been built algorithm. However, enhance performance, need strengthen information collection covering diverse coastal bodies optimize variables indicators. study provides technical support large-scale long-term understanding biogeochemical processes matter, well new management strategy quality monitoring.

Язык: Английский

Процитировано

3
δ13C and δ15N isoscapes from the Coastal Gulf of California based on Pyropia (Bangiales: Rhodophyta) DOI

Maria Jose Castaneda-Mercado,

Raúl O. Martínez‐Rincón, Karla León-Cisneros

и другие.

Estuarine Coastal and Shelf Science, Год журнала: 2025, Номер unknown, С. 109220 - 109220

Опубликована: Фев. 1, 2025

Язык: Английский

Процитировано

0
Distribution, pollution, and human health risks of persistent and potentially toxic elements in the sediments around Hainan Island, China DOI

Zhiwei Che,

Waqas Ahmed,

Jiechang Weng

и другие.

Marine Pollution Bulletin, Год журнала: 2022, Номер 174, С. 113278 - 113278

Опубликована: Янв. 1, 2022

Язык: Английский

Процитировано

14
The impact of coastal upwelling on coral reef ecosystem under anthropogenic influence: Coral reef community and its response to environmental factors DOI Creative Commons
Wentao Zhu,

Yuxiao Ren,

Xiangbo Liu

и другие.

Frontiers in Marine Science, Год журнала: 2022, Номер 9

Опубликована: Сен. 28, 2022

Mass coral bleaching is a severe threat to reefs in the era of global warming, and upwelling areas may serve as thermal refugia for by mitigating effects heating anomalies. This study seeks examine impact Qiongdong (QDU) on coastal Hainan Island. The environmental variables (i.e., physiochemical parameters, land use) differed significantly non-upwelling areas. In particular, presence colder more saline water was important indicator upwelling. QDU, turf algae macroalgae dominated communities, but habitat-specific environment development contributed lower calcified algae, larvae replenishment live corals cover. Lower abundance fishes could be attributed disappearance corals, increase coverage, low habitat complexity strong wave exposure at stations. Upwelling-related exposure, use potential local stressors were revealed major driving factors related significant spatial changes stony fish communities. Overall, present findings suggest that has provide refuge reefs, severely affected anthropogenic activities.

Язык: Английский

Процитировано

11
δ13C and δ15N stable isotopes demonstrate seasonal changes in the food web of coral reefs at the Wuzhizhou Island of the South China sea DOI Creative Commons
Hongyang Yin, Yuting Chen,

Wengang Ma

и другие.

Ecological Indicators, Год журнала: 2023, Номер 146, С. 109852 - 109852

Опубликована: Янв. 2, 2023

With a high species diversity of coral reefs, Wuzhizhou (WZZ) is tropical marine ranch built by China. In the present study, we investigated structure and function reef food webs on WZZ in Sanya to understand how climate change human activities affected ecosystems. Using carbon nitrogen stable isotopes Bayesian mixture models, assessed major organic matter pathways causes seasonal variation fauna isotope values delineate ecosystem function. Macroalgae benthic microalgae were primary sources feeding this web, while there also some notable variations. Nutrient changes caused temperature, upwelling, cyclones might be reasons for consumer community composition or isotopes. Seasonal environmental did not affect stability nutrient web WZZ.

Язык: Английский

Процитировано

6
Spatial heterogeneity of sedimentary organic matter sources in the Yangtze River estuary: Implications from fatty acid biomarkers DOI
Yunhui Wang, Ni Su, Ergang Lian

и другие.

Marine Pollution Bulletin, Год журнала: 2024, Номер 201, С. 116249 - 116249

Опубликована: Март 13, 2024

Язык: Английский

Процитировано

2
Effects of deep-sea cage culture on water quality and stable carbon and nitrogen isotopes of suspended particulate organic matter in the Yellow Sea Cold Water Mass DOI
Shengjie Xu, Shuai Shi, Li Li

и другие.

Marine Pollution Bulletin, Год журнала: 2024, Номер 209, С. 117099 - 117099

Опубликована: Окт. 11, 2024

Язык: Английский

Процитировано

2
Using Stable Isotopes (δ18O and δD) to Study the Dynamics of Upwelling and Other Oceanic Processes in Northwestern South China Sea DOI
Fengxia Zhou, Junhui Wu, Fajin Chen

и другие.

Journal of Geophysical Research Oceans, Год журнала: 2021, Номер 127(1)

Опубликована: Дек. 23, 2021

Abstract Few systematic investigations use isotopic compositions (δ 18 O and δD) of seawater together with water temperature salinity to trace the dynamic processes in upwelling area. This study presents depth‐specific δ O, δD, (S), data samples collected from northwestern South China Sea (NWSCS) during spring summer 2018 other oceanic physical processes. Strong is observed southwestern area NWSCS both based on distribution temperature. In spring, lower has generally higher δD values than studied areas, while this phenomenon not summer. indicates different hydrodynamic conditions these seasons. The eastward advection upwelled contributes phenomenon, which can be supported by O‐S relationships. regression line slope that spring. Five masses are defined west NWSCS, offshore upper (OUW) mainly formed mixing coastal deep (ODW). We principle mass conservation estimate relative contributions ODW O. 40% OUW, it 69%. method using stable isotopes event quantifies contribution obtains more information compared traditional hydrological observations.

Язык: Английский

Процитировано

14