Thermohaline variability and geostrophic circulation in the southern portion of the Gulf of California

Castro, Rubén; Durazo, Reginaldo; Mascarenhas, A.; Collins, Curtis A.; Trasviña, Armando

doi:10.1016/j.dsr.2005.09.010

Cited by 64 publications

(74 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…4 shows the temperature-salinity relationship for the TRIAXUS data. Water mass characteristics have been adopted from Castro et al (2006) As discussed above, CCW is typically observed at the Gulf's entrance, but Fig. 1 and historical analyses suggest that tropical surface waters (TSW) can find their way to the Gulf's entrance in autumn (Lavín and Marinone, 2003).…”

Section: Northern Sectionmentioning

confidence: 99%

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

Collins

Castro²,

Mascarenhas³

2015

Deep Sea Research Part II: Topical Studies in Oceanography

Self Cite

View full text Add to dashboard Cite

a b s t r a c tThe structure of an upper ocean front at the entrance to the Gulf of California is described. The front occurred in a region of strong cyclonic shear between fresher Pacific waters, which flowed into the Gulf along Sinaloa, and salty Gulf of California waters, which flowed out of the Gulf along Baja California. Observations included two high-resolution hydrographic sections across the entrance to the Gulf. One section used a towed CTD that profiled from near surface to 125 m. A second across-Gulf section was obtained using CTDs spaced about every 10 km. Both sections indicated a nearly vertical salinity front near 108.61W, which extended to a depth of 120 m at the northern front. The surface salinity change across the front was ΔS$0.4 and the width of the front 10-15 km. The surface horizontal mixing ratio, À 0.15 to À 0.7, indicated that salinity dominated the density change. The mixed layer was strongly developed to a depth of $ 45 m. Features that were observed at the front included a surface jet (10 km wide, 0.25 m s À 1 ), subduction from the mixed layer to the top of the pycnocline, evidence of symmetric instability driven by atmospheric cooling of surface waters, and a deformation rate of À 0.5 Â 10 À 5 s À 1 . Northward ageostrophic currents in the upper 60 m extended inflow 55 km to the west of the surface front. Immediately below the bottom of the mixed layer, the seasonal pycnocline was characterized by a 15-m thick and 50-km wide salinity maximum (minimum), S ¼ 34.9-35 (S ¼34.3-34.4) for the outflow (inflow). These features were not distinct in the frontal zone. Temperature flux and diffusivity were estimated to be about 7.6 Â 10 À 2 1C m s À 1 and 8600 m 2 s À 1 , respectively.Published by Elsevier Ltd.

show abstract

Section: Northern Sectionmentioning

confidence: 99%

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

Collins

Castro²,

Mascarenhas³

2015

Deep Sea Research Part II: Topical Studies in Oceanography

Self Cite

View full text Add to dashboard Cite

show abstract

“…Site fidelity is typical in adult seahorses . Potential juvenile dispersal barriers include the formation of two gyres in the upper and central GOC regions (Alvarez-Borrego 2002;Beier 1997;Lavin et al 1997), a persistent oceanic front where the California Current Water, Tropical Surface Water, and the Gulf of California Waters converge (Castro et al 2006), and inflow of surface waters during summer months (Lavin and Marinone 2003). The patterns of gyre formation, positioning of the oceanic front, and patterns of inflow and outflow are heavily influence by inter-annual variability caused by El Niño (Lavin and Marinone 2003;Castro et al 2000).…”

Section: Demographic Historymentioning

confidence: 99%

“…Thus, the only published barriers with potential to influence H. ingens include geographic distance coupled with low dispersal ability (Craig et al 2006;Riginos and Nachman 2001), and contemporary oceanographic barriers (Bernardi et al 2003;Selkoe et al 2007;Terry et al 2000). These potential oceanographic barriers are caused by the formation of two gyres in the upper and central GOC regions (AlvarezBorrego 2002;Beier 1997;Lavin et al 1997), a persistent oceanic front in the cape of Baja region, formed by the convergence of the California Current Water, Tropical Surface Water, and the GOC Water (Castro et al 2006), and inflow of surface waters during summer months (Lavin and Marinone 2003). Despite the existence of these potential barriers, a study of gastropod distribution data shows that the majority of gastropods found in the region are unaffected by a barrier at the mouth of the GOC (Simison 2006).…”

Section: Introductionmentioning

confidence: 99%

Genetic differentiation across eastern Pacific oceanographic barriers in the threatened seahorse Hippocampus ingens

2010

View full text Add to dashboard Cite

Understanding the population structure and evolutionary history of the eastern Pacific seahorse Hippocampus ingens is critical for the effective management of this threatened species. Life history characteristics of H. ingens (site fidelity and brooding of young) may limit gene flow and lead to population differentiation. A recent study analyzing conserved fragments of the mitochondrial cyt b and control region found no population structure. We re-assess this conclusion with a phylogeographic analysis of relationships among 115 individuals of H. ingens over a broader geographic range (San Diego Bay in California, Gulf of California, Central America, Ecuador, and Peru) based on a more variable 428 base pair fragment of the control region. This expanded analysis affirms low overall nucleotide diversity relative to other seahorses (h p = 0.004), and shows evidence of a recent bottleneck and population expansion since the middle Pleistocene. AMOVA analysis shows moderate overall population structure (U ST = 0.10, P val = 0.00), and pairwise U ST estimates indicate structure between the Gulf of California and all Pacific coast localities. Knowledge of population structure in H. ingens may improve conservation efforts by identifying evolutionarily important management units, and could determine source regions in the continuing trade of seahorses for traditional Chinese medicine. The level of genetic divergence observed between the Gulf of California and all other localities sampled may distinguish the Gulf as a separate management unit. Additional phylogeographic research with more quickly evolving genetic markers and targeted sampling at the mouth of the Gulf of California is warranted to inform strategies for conservation of this threatened seahorse.

show abstract

“…Nevertheless, the large spatial scale considered in their study missed important features of subbasin scale like the tropical Pacific off central Mexico (TPCM). Smaller-scale studies in this region used hydrographic data that covered only restricted areas (Roden 1972;Castro et al 2000Castro et al , 2006Godínez et al 2010;León-Chávez et al 2010Durazo 2015) or are not focused on water masses (Cepeda-Morales et al 2013). The scarcity of data in the TPCM, in comparison with the available amount of historical data in surrounding areas like the California Current System or the Gulf of California, has hindered the characterization of the circulation and the water masses in this region.…”

Section: Introductionmentioning

confidence: 99%

“…This current pattern, including the continuous exchanges through the entrance of the Gulf of California (Collins et al 2015), govern the spatial distribution and temporal variability of the water masses in the TPCM. In the upper layer of 1000-m depth these are Pacific Intermediate Water (PIW), Subtropical Subsurface Water [StSsW; also known as Subtropical Underwater (StUW; O'Connor et al 2002;Fiedler and Talley 2006)], California Current Water (CCW), Gulf of California Water (GCW), and Tropical Surface Water (TSW; Wyrtki 1966;Castro et al 2006;Lavín et al 2009;León-Chávez et al 2010Fiedler and Talley 2006). We preferred the name StSsW over StUW to emphasize the Southern Hemisphere origin of this water mass that reaches the TPCM with specific biogeochemical features as the minimum content of oxygen.…”

Section: Introductionmentioning

confidence: 99%

Water Masses and Circulation in the Tropical Pacific off Central Mexico and Surrounding Areas

Portela

Beier

Barton

et al. 2016

Journal of Physical Oceanography

Self Cite

View full text Add to dashboard Cite

The seasonal variations and the interactions of the water masses in the tropical Pacific off central Mexico (TPCM) and four surrounding areas were examined based on an extensive new hydrographic database. The regional water masses were redefined in terms of absolute salinity (S A ) and conservative temperature (Q) according to the Thermodynamic Equation of Seawater 2010 (TEOS-10). Hydrographic data and the evaporation minus (precipitation 1 runoff) balance were used to investigate the origin and seasonality of two salinity minima in the area. The shallow (50-100 m) salinity minimum originates with the California Current System and becomes saltier as it extends southeastward and mixes with tropical subsurface waters while the surface salinity minimum extends farther north in the TPCM in summer and fall because of the northward advection of tropical surface waters. The interactions between water masses allow a characterization of the seasonal pattern of circulation of the Mexican Coastal Current (MCC), the tropical branch of the California Current, and the flows through the entrance of the Gulf of California. The seasonality of the MCC inferred from the distribution of the water masses largely coincides with the geostrophic circulation forced by an annual Rossby wave.

show abstract

Thermohaline variability and geostrophic circulation in the southern portion of the Gulf of California

Cited by 64 publications

References 18 publications

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

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

Genetic differentiation across eastern Pacific oceanographic barriers in the threatened seahorse Hippocampus ingens

Water Masses and Circulation in the Tropical Pacific off Central Mexico and Surrounding Areas

Contact Info

Product

Resources

About