Influence of winds, geostrophy and typhoons on the seasonal variability of the circulation in the Gulf of Tonkin: A high-resolution 3D regional modeling study

Piton, Violaine; Herrmann, Marine; Marsaleix, Patrick; Duhaut, Thomas; Ngoc, Trinh Bich; Tran, Manh Cuong; Shearman, Kipp; Ouillon, Sylvain

doi:10.1016/j.rsma.2021.101849

Cited by 12 publications

(18 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our reference configuration, hereafter called GOT_REF, is an update of the configuration of Piton et al (2021). The model domain covers the GOT area.…”

Section: Methods Model and Data Symphonie Model And General Configurationmentioning

confidence: 99%

“…In most modeling studies to date, the RR was set up with only one mouth (or input grid point) using monthly or annual climatological runoff because more realistic runoff at the hydrological station was unavailable (Ding et al, 2013;Gao et al, 2013). In this study and in Piton et al (2021), the river condition is configured as realistically as possible.…”

Section: River Configurationsmentioning

confidence: 99%

“…The main objectives of this section are to provide a general description of the patterns of the seasonal circulation at the scale of the GOT from GOT_REF, to assess the consistency of model results with previous studies (or evidence their specificities) and to provide a qualitative assessment by comparing to observations. As a description of the general circulation and model verification (in particular using satellite data) have been provided recently by Piton et al (2021) from a very similar configuration, we do not provide a detailed analysis. We introduce the section by a discussion of the first Rossby radius, continue with the basin-scale circulation, evaluation of tidal elevation and with the comparison to in situ temperature and salinity data and surface current velocity from high-frequency radars in the area of the RR plume.…”

Section: General Circulation and Model Assessmentmentioning

confidence: 99%

“…It is a meso-tidal region, dominated by diurnal constituents (K1, O1) as described for instance by Nguyen et al (2014) and Piton et al (2020). The ocean circulation of the Gulf of Tonkin (hereafter GOT) has been examined by several authors (e.g., Ding et al, 2013;Gao et al, 2014;Rogowski et al, 2019; for a recent review see Piton et al, 2021). Using model results and observational data, they all agree that the winter circulation at the gulf scale is cyclonic and driven by wind.…”

Section: Introductionmentioning

confidence: 96%

“…Wu et al (2008) showed that the flow through Hainan Strait has an impact on the circulation in summer: if it is inflow, the circulation is mainly cyclonic and vice versa. From high-resolution model pluri-annual simulations, Piton et al (2021) found a basin-scale anticyclonic circulation in summer. They also suggest that the surface circulation is mainly ageostrophic, as a consequence from the monsoon wind forcing, except along the Vietnamese coast where the southward coastal current has a dominant densitydriven component.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Variability of the Red River Plume in the Gulf of Tonkin as Revealed by Numerical Modeling and Clustering Analysis

et al. 2021

Self Cite

View full text Add to dashboard Cite

We study the daily to interannual variability of the Red River plume in the Gulf of Tonkin from numerical simulations at high resolution over 6 years (2011–2016). Compared with observational data, the model results show good performance. To identify the plume, passive tracers are used in order to (1) help distinguish the freshwater coming from different continental sources, including the Red River branches, and (2) avoid the low salinity effect due to precipitation. We first consider the buoyant plume formed by the Red River waters and three other nearby rivers along the Vietnamese coast. We show that the temporal evolution of the surface coverage of the plume is correlated with the runoff (within a lag), but that the runoff only cannot explain the variability of the river plume; other processes, such as winds and tides, are involved. Using a K-means unsupervised machine learning algorithm, the main patterns of the plume and their evolution in time are analyzed and linked to different environmental conditions. In winter, the plume is narrow and sticks along the coast most of the time due to the downcoast current and northeasterly wind. In early summer, the southwesterly monsoon wind makes the plume flow offshore. The plume reaches its highest coverage in September after the peak of runoff. Vertically, the plume thickness also shows seasonal variations. In winter, the plume is narrow and mixed over the whole water depth, while in summer, the plume can be detached both from the bottom and the coast. The plume can deepen offshore in summer, due to strong wind (in May, June) or specifically to a recurrent eddy occurring near 19°N (in August). This first analysis of the variability of the Red River plume can be used to provide a general picture of the transport of materials from the river to the ocean, for example in case of anthropogenic chemical substances leaked to the river. For this purpose, we provide maps of the receiving basins for the different river systems in the Gulf of Tonkin.

show abstract

“…Our reference configuration, hereafter called GOT_REF, is an update of the configuration of Piton et al (2021). The model domain covers the GOT area.…”

Section: Methods Model and Data Symphonie Model And General Configurationmentioning

confidence: 99%

Section: River Configurationsmentioning

confidence: 99%

Section: General Circulation and Model Assessmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Variability of the Red River Plume in the Gulf of Tonkin as Revealed by Numerical Modeling and Clustering Analysis

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Climate change impact on sea surface winds in Southeast Asia

Herrmann

Nguyen-Duy

Ngo‐Duc

et al. 2021

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

Numerical representation and climate projections of sea surface winds over Southeast Asia (SEA) are assessed here using an ensemble of the Coupled Model Intercomparison Project Phase 5 (CMIP5) downscaled simulations performed over the 20th and 21st centuries under Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios within the Coordinated Regional Climate Downscaling EXperiment (CORDEX)‐SEA project. The ensemble is based on two regional climate models (RCMs: RegCM4 and RCA4), and CMIP5 simulations are performed with five global climate models (GCMs: CNRM_CM5, HadGEM2, GFDL, MPI‐ESM‐MR, EC‐Earth). Comparison with QuikSCAT satellite data shows that dynamical downscaling improves sea surface wind speed representation, mainly by reducing its underestimation. The level of improvement depends on the RCM choice, GCM performance, and wind strength. Our results reveal significant differences in modelled projections of sea surface wind, depending on the model, RCP, region, and season. GCMs simulate weak and contrasted changes, stronger for RCP8.5, with no clear common trend. RCA4 simulates weak changes, with high similarities between pairs, but contrasted results between RCPs. RegCM4 simulate stronger changes, with a weakening of average and intense winds for all seasons, stronger in June–August, and in RCP8.5 than in RCP4.5. RCA4 and RegCM4 simulate different changes, with no clear common trend except a weakening of seasonal and intense winds and an increase of seasonal wind interannual variability for June–August in RCP4.5, stronger for RegCM4. This corresponds to a weakening of the boreal summer monsoon and a slight increase of its interannual variability and presumably to a decrease of the tropical cyclone frequency. Differences in seasonal sea surface wind changes between models are related to differences in sea level pressure gradient changes. For a given RCM, those differences are partly related to the differences between parent GCMs. Finally, results suggest that uncertainties related to the RCM choice are larger than those related to the GCM choice.

show abstract

Assessment of relative dispersion in the Gulf of Tonkin using numerical modeling and HF radar observations of surface currents

Tran

Sentchev

Berti

et al. 2022

Continental Shelf Research

View full text Add to dashboard Cite

Influence of winds, geostrophy and typhoons on the seasonal variability of the circulation in the Gulf of Tonkin: A high-resolution 3D regional modeling study

Cited by 12 publications

References 57 publications

Variability of the Red River Plume in the Gulf of Tonkin as Revealed by Numerical Modeling and Clustering Analysis

Variability of the Red River Plume in the Gulf of Tonkin as Revealed by Numerical Modeling and Clustering Analysis

Climate change impact on sea surface winds in Southeast Asia

Assessment of relative dispersion in the Gulf of Tonkin using numerical modeling and HF radar observations of surface currents

Contact Info

Product

Resources

About