Temporal and spatial variation of the surface winds in the Gulf of California

Abstract

Satellite‐derived data (NSCAT and Quickscat) are used to study the annual variability of the sea surface winds over the Gulf of California. Our results indicate that the monsoon character of the winds have been exaggerated. Particularly erroneous is the concept that the wind has two symmetrically, gulf‐following, preferred directions. For some years, this has been the main characteristic used to explain the dynamics of the gulf and it has influenced the development of the ocean circulation models of the region. The surface winds have an average direction that follows that of the gulf, but generally track in a south‐eastward direction. The summer reversal (i.e. wind flowing from the south‐east) occasionally occurs only in the southern regions. The magnitude and standard deviation of the winds are largest in winter. There is an important east‐west gradient in their magnitude and the winds on the peninsular side are generally stronger than those of the continental side.

An Overview of the Physical Oceanography of the Gulf of California

“…Direct evidence for this pattern was obtained from satellite-tracked drifters by Lavín et al (1997a) and from current meter data by Palacios-Hernández et al (2002). The corresponding hydrographic sections show that in summer the strong stratification is characterized by doming isolines, which leads to a low center in dynamic height and cyclonic geostrophic currents with surface speed comparable to that of the drifters, while in winter stratification is much weaker and the isolines are depressed in the center of the basin, which generates a high in dynamic topography.…”

“…The wind in the GC has a marked seasonal behavior, product of the seasonal changes of atmospheric pressure centers in its vicinity and the channeling effect of the mountain chains in both sides: in autumn, winter and spring the wind blows from the NW with a speed of 8 to 12 ms −1 , while in summer it blows from the SE with a mean speed of ≤5 ms −1 (Roden, 1964;Badan-Dangon et al, 1991b;Merrifield and Winant, 1989;Badan, this volume). Recent wind velocity observations from the NSCAT and QuickScat satellite scatterometers (Parés et al, 2003) suggest that the summer reversals may not occur in the NGC and only for periods of a few days in the SGC, which would explain their absence in quarterly climatologies from ship reports (Fiedler, 1992). (iii) Surface fluxes.…”

“…Details of the lateral structure of the circulation are also obtained: the seasonally-reversing gyre in the NGC is reproduced, and in the SGC there is anticyclonic surface circulation in winter and a cyclonic circulation in summer. A non-linear, vertically-entraining version of the model was used by Beier (1999) and Palacios-Hernández et al (2002) to demonstrate that the difference in stratification due to winter mixing is a possible cause for the inequality in the duration of the cyclonic and anticyclonic regimes in the NGC. The simulated seasonal circulation and sea surface temperatures are closer to observations than the model of Beier (1997).…”

Properties of an upper ocean front associated with water mass boundaries at the entrance to the Gulf of California, November 2004

“…The atmosphere is generally cooler than the ocean in November and the resulting air-sea buoyancy flux contributes to deepening of the mixed layer, convective overturning and symmetric instability (Taylor and Ferrari, 2010). Although northerly winds dominate from late summer though early spring in the Gulf (Parés-Sierra et al, 2003, southerly winds occur six percent of time (National Geospatial Intelligence Agency, 1994). These southerly winds provide a down front component of wind stress which transport more dense surface water toward less dense surface water, initiating vertical motions in the upper ocean including symmetric instabilities (Taylor and Ferrari, 2010).…”

Batimetría y características hidrográficas (Mayo, 2007) en las Cuencas de Consag y Wagner, Norte del Golfo de California, México

“…Los factores que afectan a la dinámica del Golfo de California (GC) son resultado de: (a) el viento (Parés-Sierra et al, 2003); (b) las mareas (Alvarez-Borrego y Gaxiola-Castro, 1988); y (c) la radiación solar (evaporación) (Bray, 1988;Lavín y Organista, 1988). El GC es una región muy compleja que presenta una alta productividad (Alvarez-Borrego et al, 1978;Alvarez-Borrego y Gaxiola-Castro, 1988).…”