| |
| |
|
|
|
|
| |
 |
Ocean eddies, fronts, and air-sea exchanges: Observations and high resolution simulations
|
| |
|
|
Seasonal response of river plume to freshwater discharge in river-dominated ocean margins: a multi-salinity products analysis and inter-regional comparison
P-P4-08
Yang Feng* , Southern University of Science and Technology
NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
Dimitris Menemenlis, 2. NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
Huijie Xue, 1. State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
Peng Xiu, State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
Presenter Email: yfeng.ocean.1982@outlook.com |
| River plume dynamics generated considerable research interests for the past decade due to the important role in coastal ecology, biogeochemistry, shoreline morphology and climate. Remote sensing and numerical models yield synoptic data to understand river plume variability, which are unattainable from cruise observations or moorings. Previous investigators have utilized satellite ocean color or configured regional models in studying the dispersal of river plumes, with focusing on a certain continental shelf. In this study, we used high-resolution satellite sea surface salinity (SSS) observations and a global configured 18-km resolution, eddy permitting model with the river source improvement to investigate seasonal variability of river plumes at three continental shelves, including the Northern Brazilian (NB) Shelf; the Northern Angola (NA) Basin; the Texas-Louisiana (TL) Shelf. A comparison with world ocean data (WOD) base has shown that SMAP SSSA field had smallest RMSE, followed by SMOS and ECCO2. Typical river plume dispersal patterns are all well identified from the three products, including: (1) the eastward transport of the Amazon River Plume in July - November; (2) the southward dispersal of the Congo River plume in February-March; (3) the July - September reversal of the Mississippi River plume. We found that the plume area responded to freshwater discharge differently for these three regions. The response time is about 2-mo for the NB shelf, 1-mo for the NA Basin and 4-mo for the TL shelf. About 70 -80% variability can be explained by freshwater discharge at the NB shelf and the NA Basin. In contrast, only about 40 - 50% can be explained at the TL shelf. The delay time reflected the lag between maximum river discharge and external forcing, primarily wind and ambient currents. Lower explained variance at TL shelf is because the shelf is wider and located at the mid-latitude, resulting the more bottom advected river plume rather than the surface advected. Our ensemble analysis provided strong support for river plume dynamic theories from idealized and realistic models. |
|
|
|
|
|
|
|
|