The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of Californ... more The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of California and the Baja California Peninsula, is documented from QuikScat satellite observations. The typical wind pattern in this region is towards the southeast, but between 9 and 12 February 2002 it was modified by Santa Ana winds, changing in direction towards the south, southwest and west. The changes were notable at first in southern California, but the largest indices of variation occurred between 26ºN and 28ºN off the Baja California Peninsula, with maxima in the Gulf of California, mainly in the northern part. The maximum extension of the winds to the west of the coast was on 11 February, reaching 32ºN and 125ºW, or ~700 km; however, towards the southwest the winds extended to 25ºN and 124ºW, or ~1000 km. The topography of the peninsula plays an important role in controlling the winds passing from the Gulf of California to the Pacific, causing plumes of sand and dust in several location...
Seasonal variability of the sea surface temperature (SST) in the Eastern Tropical Pacific were st... more Seasonal variability of the sea surface temperature (SST) in the Eastern Tropical Pacific were studied. For this purpose the following data were analyzed: SST and wind data from the Comprehensive Ocean–Atmosphere Data Set from 1978 to 1997, temperature and salinity fields from the LEVITUS climatology and sea surfac heights from TOPEX/Poseidon from 1993 to 2002. Various locally important factors that modulate this variability were identified: (1) the influence of the Gulf of California with the seasonal variability of the California Current, which extend about 200 km from the mouth towards the south and west, and about 300 km from the peninsula’s west side toward the north; (2) the influence of the Gulfs of Tehuantepec and Papagayo where, due to the behavior of the winds, a local cooling of the surface during winter is generated; (3) upwelling at the Equator, off Cabo Corrientes, and off the west coast of Baja California; (4) spatial and temporal variation of the Inter-Tropical Conve...
Based on results from a ROMS numerical model, the dynamics of the Mexican Central Pacific was stu... more Based on results from a ROMS numerical model, the dynamics of the Mexican Central Pacific was studied during three years (2003-2005). The model reproduces the mean and seasonal variability of sea surface temperature, as well as mesoscale eddies and meanders from satellite observations. The model adequately represents the main currents in the region: California Current, Mexican Coastal Current, and Gulf of California currents. The Gulf of California currents are linked to the intensification of the Mexican Coastal Current and interact in such a way that the lateral shear generates eddies at the entrance to the Gulf of California. The mesoscale eddies were found to have a depth of ~200 m. The eddies generated in the area (internal Rossby radius of deformation, Rd = 40 km) had a diameter L of ~300 km, an orbital speed of 20-30 cm s-1, and a westward translation speed of ~4 cm s-1. Eddies are considered from intermediate to big (L ≈ 7.5 Rd, Ro << 1), show geostrophic dynamics, and...
ABSTRACT Results of a new implementation of a circulation model (ROMS) for the Gulf of California... more ABSTRACT Results of a new implementation of a circulation model (ROMS) for the Gulf of California are presented. The general circulation characteristics for the Gulf are described based on these results. Emphasis is placed on understanding the similarities and differences with previous model. It is shown that the seasonal circulation is dominated by a series of shallow gyres with an alternating sense of circulation and spatial scales as the wide of the gulf. We discuss the formation and evolution of these gyres in relation to theirs forcing agents (i.e. winds, boundary forcing through the mouth and geometry) and generating processes (i.e. instabilities) and dissipation. The implication of the gyres on the redistribution of characteristics is analyzed. A Lagrangean description of the gulf is presented.
The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of Californ... more The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of California and the Baja California Peninsula, is documented from QuikScat satellite observations. The typical wind pattern in this region is towards the southeast, but between 9 and 12 February 2002 it was modified by Santa Ana winds, changing in direction towards the south, southwest and west. The changes were notable at first in southern California, but the largest indices of variation occurred between 26ºN and 28ºN off the Baja California Peninsula, with maxima in the Gulf of California, mainly in the northern part. The maximum extension of the winds to the west of the coast was on 11 February, reaching 32ºN and 125ºW, or ~700 km; however, towards the southwest the winds extended to 25ºN and 124ºW, or ~1000 km. The topography of the peninsula plays an important role in controlling the winds passing from the Gulf of California to the Pacific, causing plumes of sand and dust in several location...
The general circulation of Todos Santos Bay was studied using the ROMS numerical model for the su... more The general circulation of Todos Santos Bay was studied using the ROMS numerical model for the summer season. The model was forced with the California Current System and by synoptic winds, which are mainly towards the equator. The circulation is characterized by two systems: one at the exterior with a strong southward flow that enters to the bay but limited
Three regions (cephalic, central, and caudal) of the dorsal and ventral muscle tissue (R1 through... more Three regions (cephalic, central, and caudal) of the dorsal and ventral muscle tissue (R1 through R6) and the caudal peduncle muscle tissue (CPMT) of 20 farmed bluefin tuna (Thunnus orientalis) were analyzed for mercury (Hg) and cadmium (Cd) concentrations. Region 1 (cephalic-ventral) had significantly lower concentrations of Hg but significantly higher concentrations of Cd than did the other regions. However, average metal concentrations of all regions (R1 through R6) were only 6% lower for Hg and were not significantly different for Cd from those in the CPMT. Therefore, the CPMT was used to monitor the concentrations of these two metals in more than 100 farmed tuna collected from July 2004 to January 2009 under the assumption that the Cd concentrations in the CPMT would be representative of the Cd concentration in the whole body and that the Hg concentrations would be, in the worst case, overestimated by approximately 6%. The Hg and Cd concentrations in these tuna were inversely related to the condition index, i.e., the tuna in better condition had the lowest concentrations of these metals. The mean concentrations in the CPMT of all fish analyzed were 0.31 ± 0.17 μg/g wet weight for Hg and 0.007 ± 0.006 μg/g wet weight for Cd. These concentrations were below the limits established by Mexican regulations for seafood (1.0 and 0.5 μg/g for Hg and Cd, respectively) and Japan (0.4 μg/g for Hg).
The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of Californ... more The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of California and the Baja California Peninsula, is documented from QuikScat satellite observations. The typical wind pattern in this region is towards the southeast, but between 9 and 12 February 2002 it was modified by Santa Ana winds, changing in direction towards the south, southwest and west. The changes were notable at first in southern California, but the largest indices of variation occurred between 26ºN and 28ºN off the Baja California Peninsula, with maxima in the Gulf of California, mainly in the northern part. The maximum extension of the winds to the west of the coast was on 11 February, reaching 32ºN and 125ºW, or ~700 km; however, towards the southwest the winds extended to 25ºN and 124ºW, or ~1000 km. The topography of the peninsula plays an important role in controlling the winds passing from the Gulf of California to the Pacific, causing plumes of sand and dust in several location...
Seasonal variability of the sea surface temperature (SST) in the Eastern Tropical Pacific were st... more Seasonal variability of the sea surface temperature (SST) in the Eastern Tropical Pacific were studied. For this purpose the following data were analyzed: SST and wind data from the Comprehensive Ocean–Atmosphere Data Set from 1978 to 1997, temperature and salinity fields from the LEVITUS climatology and sea surfac heights from TOPEX/Poseidon from 1993 to 2002. Various locally important factors that modulate this variability were identified: (1) the influence of the Gulf of California with the seasonal variability of the California Current, which extend about 200 km from the mouth towards the south and west, and about 300 km from the peninsula’s west side toward the north; (2) the influence of the Gulfs of Tehuantepec and Papagayo where, due to the behavior of the winds, a local cooling of the surface during winter is generated; (3) upwelling at the Equator, off Cabo Corrientes, and off the west coast of Baja California; (4) spatial and temporal variation of the Inter-Tropical Conve...
Based on results from a ROMS numerical model, the dynamics of the Mexican Central Pacific was stu... more Based on results from a ROMS numerical model, the dynamics of the Mexican Central Pacific was studied during three years (2003-2005). The model reproduces the mean and seasonal variability of sea surface temperature, as well as mesoscale eddies and meanders from satellite observations. The model adequately represents the main currents in the region: California Current, Mexican Coastal Current, and Gulf of California currents. The Gulf of California currents are linked to the intensification of the Mexican Coastal Current and interact in such a way that the lateral shear generates eddies at the entrance to the Gulf of California. The mesoscale eddies were found to have a depth of ~200 m. The eddies generated in the area (internal Rossby radius of deformation, Rd = 40 km) had a diameter L of ~300 km, an orbital speed of 20-30 cm s-1, and a westward translation speed of ~4 cm s-1. Eddies are considered from intermediate to big (L ≈ 7.5 Rd, Ro << 1), show geostrophic dynamics, and...
ABSTRACT Results of a new implementation of a circulation model (ROMS) for the Gulf of California... more ABSTRACT Results of a new implementation of a circulation model (ROMS) for the Gulf of California are presented. The general circulation characteristics for the Gulf are described based on these results. Emphasis is placed on understanding the similarities and differences with previous model. It is shown that the seasonal circulation is dominated by a series of shallow gyres with an alternating sense of circulation and spatial scales as the wide of the gulf. We discuss the formation and evolution of these gyres in relation to theirs forcing agents (i.e. winds, boundary forcing through the mouth and geometry) and generating processes (i.e. instabilities) and dissipation. The implication of the gyres on the redistribution of characteristics is analyzed. A Lagrangean description of the gulf is presented.
The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of Californ... more The evolution and extension of Santa Ana winds over the Pacific Ocean, off the coasts of California and the Baja California Peninsula, is documented from QuikScat satellite observations. The typical wind pattern in this region is towards the southeast, but between 9 and 12 February 2002 it was modified by Santa Ana winds, changing in direction towards the south, southwest and west. The changes were notable at first in southern California, but the largest indices of variation occurred between 26ºN and 28ºN off the Baja California Peninsula, with maxima in the Gulf of California, mainly in the northern part. The maximum extension of the winds to the west of the coast was on 11 February, reaching 32ºN and 125ºW, or ~700 km; however, towards the southwest the winds extended to 25ºN and 124ºW, or ~1000 km. The topography of the peninsula plays an important role in controlling the winds passing from the Gulf of California to the Pacific, causing plumes of sand and dust in several location...
The general circulation of Todos Santos Bay was studied using the ROMS numerical model for the su... more The general circulation of Todos Santos Bay was studied using the ROMS numerical model for the summer season. The model was forced with the California Current System and by synoptic winds, which are mainly towards the equator. The circulation is characterized by two systems: one at the exterior with a strong southward flow that enters to the bay but limited
Three regions (cephalic, central, and caudal) of the dorsal and ventral muscle tissue (R1 through... more Three regions (cephalic, central, and caudal) of the dorsal and ventral muscle tissue (R1 through R6) and the caudal peduncle muscle tissue (CPMT) of 20 farmed bluefin tuna (Thunnus orientalis) were analyzed for mercury (Hg) and cadmium (Cd) concentrations. Region 1 (cephalic-ventral) had significantly lower concentrations of Hg but significantly higher concentrations of Cd than did the other regions. However, average metal concentrations of all regions (R1 through R6) were only 6% lower for Hg and were not significantly different for Cd from those in the CPMT. Therefore, the CPMT was used to monitor the concentrations of these two metals in more than 100 farmed tuna collected from July 2004 to January 2009 under the assumption that the Cd concentrations in the CPMT would be representative of the Cd concentration in the whole body and that the Hg concentrations would be, in the worst case, overestimated by approximately 6%. The Hg and Cd concentrations in these tuna were inversely related to the condition index, i.e., the tuna in better condition had the lowest concentrations of these metals. The mean concentrations in the CPMT of all fish analyzed were 0.31 ± 0.17 μg/g wet weight for Hg and 0.007 ± 0.006 μg/g wet weight for Cd. These concentrations were below the limits established by Mexican regulations for seafood (1.0 and 0.5 μg/g for Hg and Cd, respectively) and Japan (0.4 μg/g for Hg).
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