Large diurnal wind variability over the western and northern Campeche Bank caused by the low latitude of the Yucatan Peninsula and its interaction with Easterlies

Jorge Zavala Hidalgo, Rosario de Lourdes Romero Centeno

Atmospheric Research | Volume 265

Autores: Ma. Eugenia Allende-Arandía, Jorge Zavala-Hidalgo, Rosario Romero-Centeno*, Gemma L. Franklin, Nidia Taylor-Espinosa, María Elena Osorio-Tai

* Ciencias Atmosféricas | Interacción Océano-Atmósfera



he northern and western Campeche Bank have an intense diurnal cycle with a significant offshore extension. Wind observations along the coast of the southern Gulf of Mexico, confirm that the breeze phenomenon occurs with great intensity and extension. To analyze this mesoscale phenomenon, a numerical simulation of high spatial-temporal resolution was performed using the Weather Research and Forecasting model (WRF). Diurnal wind components were fitted to a sinusoidal function, and the resulting parameters were used to obtain monthly elliptical hodographs. The greatest amplitude of the diurnal signal occurred in April, at the cays and islands, whereas in the continental region the amplitude of the diurnal component was greatest on the northern and western coasts of the Yucatan Peninsula. The large amplitude of this diurnal wind component is determined by a combination of different factors: the latitude, the geographical configuration of the southern Gulf of Mexico, the orography, the dominant easterly winds, and the development of an intense thermal contrast. Regarding the analysis of the wind components, a strong asymmetry was found between the sea-breeze and the land-breeze. Sea breeze winds are intense over the ocean, exceeding 10 ms−1 at 100 km from the coastline. The friction effect over land is also perceptible, reducing the wind magnitude by more than 6 ms−1. The formation of a breeze cell circulation with opposing easterly winds creates a strong convergence zone. It was found that the Yucatan Peninsula location, due to its relatively low latitude and altitude, in combination with the predominant easterly winds, favors these dynamics.

Vía: Atmospheric Research