Effect of the spatial and temporal variability of winds on the circulation in the Gulf of California

Abstract

A numerical model of the Gulf of California is used to study and compare the circulation due to a spatially homogeneous and time symmetric wind (VI) and one derived from QuikScat data (VO). The mean and seasonal evolution of the currents are presented for both cases, as well as their associated fields of kinetic energy, vorticity and horizontal divergence. On average, the currents generated by VI are weaker than those of VO and with a simpler spatial structure: anticyclonic circulation in the south and irregular in the north. In both cases, variability is larger on the continental coast in shallow waters but differs in the duration of the cyclonic/anticyclonic gyre in the northern basin. The magnitude of the currents also shows differences between the experiments because of stronger winds from autumn to winter for VO and during summer for VI. The average of the kinetic energy is greater for both experiments on the continental side. High relative vorticity cores are present along the gulf for VO. Close to the coast, the divergence and convergence is large in both cases, and large only for VO far from the coast. The temporal evolution of the kinetic energy, vorticity and divergence is more irregular for VO. Vorticity and divergence is generated only on the coasts and for strong winds for VI, whereas for VO it is also produced as a result of the wind stress curl.

Keywords

• wind variability
• circulation
• Gulf of California