Impact of Continental Freshwater Runoff on Coastal Sea Level

Durand, Fabien; Piecuch, Christopher G.; Becker, Mélanie; Papa, Fabrice; Raju, Sherin V.; Khan, Jamal Uddin; Ponte, Rui M.

doi:10.1007/s10712-019-09536-w

Cited by 58 publications

(51 citation statements)

References 126 publications

(147 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such a behavior is definitely associated to coastal processes that were not visible with former altimetry products (e.g., Cazenave et al, 2017, Birol et al, 2017. This may be the result of wind-induced setup, river freshwater runoff, or wave forcing on shallow shelves (e.g., Piecuch et al, 2018, Durand et al, 2019, Melet et al, 2018. At embayed coasts and estuaries and shallow areas, cross-shore winds can drive important surge, such as observed off Senegal over the wide shelf during winter upwelling (Capet et al, 2017).…”

Section: Discussionmentioning

confidence: 95%

See 1 more Smart Citation

Altimetry-based sea level trends along the coasts of Western Africa

Marti

Cazenave

Birol

et al. 2021

Advances in Space Research

View full text Add to dashboard Cite

We present results of contemporary coastal sea level changes along the coasts of western Africa, obtained from a dedicated reprocessing of satellite altimetry data done in the context of the ESA 'Climate Change Initiative' sea level project. High sampling rate (20 Hz) sea level data from the Jason-1 and Jason-2 missions over a 14-year-long time span (July 2002 to June 2016) are considered. The data were first retracked using the ALES adaptative leading edge subwaveform retracker. The X-TRACK processing system developed to optimize the completeness and accuracy of the corrected sea level time series in coastal ocean areas was then applied. From the 14-year long sea level time series finally obtained, we estimate sea level trends along the Jason-1 & 2 tracks covering the study region. We analyze regional variations in sea level trends, with a focus on the changes observed between the open ocean to the coastal zone. Compared to the conventional 1 Hz sea level products dedicated to open ocean applications, the retracked 20 Hz measurements used in this study allow us to retrieve valid sea level information much closer to the coast (less than 3-4 km to the coast, depending on the satellite track location). The main objective of this study is twofold: (1) provide sea level products in the coastal areas from reprocessed altimetry data and (2) check whether sea level changes at the coast differ from that reported in the open ocean with conventional altimetry products. In the selected region, results show that over the study period, sea level trends observed near the coast of western Africa are significantly different than offshore trends. In order to assess the robustness of the results, detailed analyses are performed at several locations to discriminate between possible drifts in the geophysical corrections and physical processes potentially able to explain the sea level changes observed close to the coast.

show abstract

Section: Discussionmentioning

confidence: 95%

“…Large river fresh water plumes can change water density and affect coastal sea level (e.g. Han and Webster, 2002;Brammer, 2014, Piecuch et al, 2018, Durand et al, 2019. Waves radiate energy over long distances in deep water without any…”

Section: Discussionmentioning

confidence: 99%

Altimetry-based sea level trends along the coasts of Western Africa

Marti

Cazenave

Birol

et al. 2021

Advances in Space Research

View full text Add to dashboard Cite

show abstract

“…To reproduce the seasonal changes in water level observed in the northern Bay of Bengal, we have also imposed an annual cycle of 35 cm amplitude along the southern open boundary in the same manner as Tazkia et al [42]. The river freshwater fluxes-one of the ingredients of coastal water-level variability [44]-are prescribed in the inland open boundaries. We have prescribed rated daily discharges at the upstream boundaries of Ganges and Brahmaputra rivers with observed data provided by Bangladesh Water Development Board (BWDB) for 2014.…”

Section: Hydrodynamic Tidal Modeling Frameworkmentioning

confidence: 99%

High-Resolution Intertidal Topography from Sentinel-2 Multi-Spectral Imagery: Synergy between Remote Sensing and Numerical Modeling

et al. 2019

Self Cite

View full text Add to dashboard Cite

The intertidal zones are well recognized for their dynamic nature and role in near-shore hydrodynamics. The intertidal topography is poorly mapped worldwide due to the high cost of associated field campaigns. Here we present a combination of remote-sensing and hydrodynamic modeling to overcome the lack of in situ measurements. We derive a digital elevation model (DEM) by linking the corresponding water level to a sample of shorelines at various stages of the tide. Our shoreline detection method is fully automatic and capable of processing high-resolution imagery from state-of-the-art satellite missions, e.g., Sentinel-2. We demonstrate the use of a tidal model to infer the corresponding water level in each shoreline pixel at the sampled timestamp. As a test case, this methodology is applied to the vast coastal region of the Bengal delta and an intertidal DEM at 10 m resolution covering an area of 1134 km 2 is developed from Sentinel-2 imagery. We assessed the quality of the DEM with two independent in situ datasets and conclude that the accuracy of our DEM amounts to about 1.5 m, which is commensurate with the typical error bar of the validation datasets. This DEM can be useful for high-resolution hydrodynamic and wave modeling of the near-shore area. Additionally, being automatic and numerically effective, our methodology is compliant with near-real-time monitoring constraints.

show abstract

“…This contribution is known as halosteric sea level changes. The discharge results in a low-salinity plume that remains at the ocean surface because of its low density and contributes locally to sea level [6]. The modification of the upper ocean heat content by the plume [7] could also lead to a thermosteric contribution to the regional sea level.…”

Section: Introductionmentioning

confidence: 99%

“…The remainder of the year, the NBC connects with the North Equatorial Countercurrent (NECC) through a retroflection zone between 5°N and 10°N, transporting the Amazon plume to the east [21,22]. Durand et al [6] suggest that the impact of the Amazon River discharge on sea level is potentially important at global and regional scales. The authors converted the Amazon discharge into units of equivalent GMSL and show that the standard deviation of its interannual variability is 0.4 mm.…”

Section: Introductionmentioning

confidence: 99%

Contribution of the Amazon River Discharge to Regional Sea Level in the Tropical Atlantic Ocean

Giffard

Llovel

Jouanno

et al. 2019

Water

View full text Add to dashboard Cite

The Amazon River is by far the largest river by volume of water in the world, representing around 17% of the global riverine discharge to the oceans. Recent studies suggested that its impact on sea level is potentially important at global and regional scales. This study uses a set of regional simulations based on the ocean model NEMO to quantify the influence of the Amazon runoff on sea level in the Tropical Atlantic Ocean. The model is forced at its boundaries with daily fields from the ocean reanalysis GLORYS2V4. Air-sea fluxes are computed using atmospheric variables from DFS5.2, which is a bias-corrected version of ERAinterim reanalysis. The particularity of this study is that interannual daily runoffs from the up-to-date ISBA-CTRIP land surface model are used. Firstly, mean state of sea level is investigated through a comparison between a simulation with an interannual river discharge and a simulation without any Amazon runoff. Then, the impact of the Amazon River on seasonal and interannual variability of sea level is examined. It was shown that the Amazon River has a local contribution to the mean state sea level at the river mouth but also a remote contribution of 3.3 cm around the whole Caribbean Archipelago, a region threatened by the actual sea level rise. This effect is mostly due to a halosteric sea level contribution for the upper 250 m of the ocean. This occurs in response to the large scale advection of the plume and the downward mixing of subsurface waters at winter time. The Amazon discharge also induces an indirect thermosteric sea level contribution. However, this contribution is of second order and tends to counterbalance the halosteric sea level contribution. Regional mass redistributions are also observed and consist in a 8 cm decrease of the sea level at the river mouth and a 4.5 increases on continental shelves of the Gulf of Mexico and Caribbean Sea. In terms of variability, simulations indicate that the Amazon discharge may contributes to 23% and 12% of the seasonal and interannual sea level variances in the Caribbean Archipelago area. These variances are first explained by the Amazon time mean discharge and show very weak sensitivity to the seasonal and interannual variability of the Amazon runoff.

show abstract

Impact of Continental Freshwater Runoff on Coastal Sea Level

Cited by 58 publications

References 126 publications

Altimetry-based sea level trends along the coasts of Western Africa

Altimetry-based sea level trends along the coasts of Western Africa

High-Resolution Intertidal Topography from Sentinel-2 Multi-Spectral Imagery: Synergy between Remote Sensing and Numerical Modeling

Contribution of the Amazon River Discharge to Regional Sea Level in the Tropical Atlantic Ocean

Contact Info

Product

Resources

About