An 8-year database of sea surface temperature (SST), 7 years of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color images, wind fields, and numerical model results are analyzed to identify regions and periods of coastal upwelling on the western and southern shelves of

[1] Numerical model experiments are conducted to address the previously unexplained anomalously high storm surge along the Florida coast of Apalachee Bay during Hurricane Dennis (2005). The 2 -3 m surge observed during this storm cannot be obviously explained by the relatively weak local winds over this bay 275 km east of the storm center. Realistic and idealized numerical experiments demonstrate that the along-shore winds to the east of the storm center built a high sea level anomaly along the coast which traveled northward to Apalachee Bay as a topographic Rossby wave. The wave was amplified as the storm moved nearly parallel to the shelf and at comparable speed to the wave phase speed. These results suggest that enlarging the domain of the storm surge forecasting models can improve the surge forecast for a storm moving along a similar track, and have now been applied to operational use.

[1] TOPEX/Poseidon satellite altimeter observations and the Naval Research Laboratory Layered Ocean Model simulations show interannual variability in the number and intensity of Tehuantepec eddies off the Mexican southwest coast. Analysis of the results illustrates that downwelling coastally trapped waves, which are generated in the equatorial Pacific, play a crucial role in the modulation and generation of Tehuantepec eddies and a dominant role in Tehuantepec eddy interannual variability. This introduces a new paradigm in which the generation and modulation of Tehuantepec eddies is not exclusively explained in terms of the strong and intermittent Tehuantepec wind events. In fact, the results show anticyclonic eddy formation during periods of calm Tehuantepec winds. That is specifically exemplified by the formation of two anticyclonic Tehuantepec eddies during a 5-month period of weak Gulf of Tehuantepec winds during summer of 1997. Furthermore, the satellite-observed and NLOM-simulated proliferation of Tehuantepec eddies during El Niño years is explained by the corresponding increase in downwelling coastally trapped waves and a lack of increase in the number and strength of Tehuantepec wind events during El Niño years.Citation: Zamudio, L

We found in an earlier study that mosquitofish (Gambusia affinis and G. holbrooki) ceased reproduction in the late summer, long before the end of warm weather, stored fat, then utilized reserves to survive the winter and initiate reproduction the following spring. We hypothesized that this pattern of fat utilization was a life history adaptation that enabled the fish to acquire food resources in the autumn then allocate them to reproduction the following spring when the fitness of the young would be greater. Here we evaluate one aspect of this hypothesis by evaluating the probability of survival to maturity and fecundity of young as a function of date of birth. We placed cohorts comprising eight to ten litters of young born early‐, mid‐ or late in the reproductive season in replicate field enclosures. The entire experiment was repeated in two different years. Early‐born young had a significantly higher probability of survival to maturity but did not differ in fecundity relative to the last cohort of the season. Early‐born young also attained maturity early enough to reproduce in their year of birth while late‐born young had to overwinter before reproduction. The fitness consequences to the mother of either producing one more litter of young at the end of the season, versus instead storing fat and reproducing the following spring are not as determinate as are the effects of date of birth on offspring fitness. Females most often gain fitness by not producing one last litter and instead over‐wintering. If, however, the overwinter survival of offspring is not influenced by their size at the end of the season, then a female's fitness could be enhanced by producing one more litter late in the season. If instead the probability of overwinter survival is strongly influenced by the size of offspring at the end of the season, then our results suggest that a female gains more by deferring reproduction and storing for overwinter survival and reproduction the following spring.

A coupled ocean and boundary layer flux numerical modeling system is used to study the upper ocean response to surface heat and momentum fluxes associated with a major hurricane, namely, Hurricane Dennis (July 2005) in the Gulf of Mexico. A suite of experiments is run using this modeling system, constructed by coupling a Navy Coastal Ocean Model simulation of the Gulf of Mexico to an atmospheric flux model. The modeling system is forced by wind fields produced from satellite scatterometer and atmospheric model wind data, and by numerical weather prediction air temperature data. The experiments are initialized from a data assimilative hindcast model run and then forced by surface fluxes with no assimilation for the time during which Hurricane Dennis impacted the region. Four experiments are run to aid in the analysis: one is forced by heat and momentum fluxes, one by only momentum fluxes, one by only heat fluxes, and one with no surface forcing. An equation describing the change in the upper ocean hurricane heat potential due to the storm is developed. Analysis of the model results show that surface heat fluxes are primarily responsible for widespread reduction (0.5°-1.5°C) of sea surface temperature over the inner West Florida Shelf 100-300 km away from the storm center. Momentum fluxes are responsible for stronger surface cooling (2°C) near the center of the storm. The upper ocean heat loss near the storm center of more than 200 MJ/m 2 is primarily due to the vertical flux of thermal energy between the surface layer and deep ocean. Heat loss to the atmosphere during the storm's passage is approximately 100-150 MJ/m 2 . The upper ocean cooling is enhanced where the preexisting mixed layer is shallow, e.g., within a cyclonic circulation feature, although the heat flux to the atmosphere in these locations is markedly reduced.