Jouanno Julien, Pallas-Sanz E., Sheinbaum J. (2018). Variability and dynamics of the Yucatan upwelling : high-resolution simulations. Journal of Geophysical Research. Oceans, 123 (2), p. 1251-1262. ISSN 2169-9275.
Titre du document
Variability and dynamics of the Yucatan upwelling : high-resolution simulations
Journal of Geophysical Research. Oceans, 2018,
123 (2), p. 1251-1262 ISSN 2169-9275
The Yucatan shelf in the southern Gulf of Mexico is under the influence of an upwelling that uplifts cool and nutrient rich waters over the continental shelf. The analysis of a set of high-resolution (x=y approximate to 2.8 km) simulations of the Gulf of Mexico shows two dominant modes of variability of the Yucatan upwelling system: (1) a low-frequency mode related to variations in position and intensity of the Loop Current along the shelf, with upwelling intensified when the Loop Current is strong and approaches to the Yucatan shelf break and (2) a high-frequency mode with peak frequency in the 6-10 days band related to wind-forced coastal waves that force vertical velocities along the eastern Yucatan shelf break. To first order, the strength and position of the Loop Current are found to control the intensity of the upwelling, but we show that high-frequency winds also contribute (approximate to 17%) to a net input of cool waters (<22.5 degrees C) on the Yucatan shelf. Finally, although more observational studies are needed to corroborate the topographic character of the Yucatan upwelling system, this study reveals the key role played by a notch along the Yucatan shelf break: a sensitivity simulation without the notch shows a 55% reduction of the upwelling.
