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Full-Text Articles in Physical Sciences and Mathematics
Detecting Submarine Groundwater Discharge With Synoptic Surveys Of Sediment Resistivity, Radium, And Salinity, John A. Breier, Crystaline F. Breier, Henrietta Edmonds
Detecting Submarine Groundwater Discharge With Synoptic Surveys Of Sediment Resistivity, Radium, And Salinity, John A. Breier, Crystaline F. Breier, Henrietta Edmonds
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
A synoptic geophysical and geochemical survey was used to investigate the occurrence and spatial distribution of submarine discharges of water to upper Nueces Bay, Texas. The 17 km survey incorporated continuous resistivity profiling; measurements of surface water salinity, temperature, and dissolved oxygen; and point measurements of dissolved Ra isotopes. The survey revealed areas of interleaving, vertical fingers of high and low conductivity extending up through 7 m of bay bottom sediments into the surface water, located within 100 m of surface salinity and dissolved Ra maxima along with peaks in water temperature and lows in dissolved oxygen. These results indicate …
Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri
Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
We tested the potential of estimating per-pixel gross primary production (GPP) directly from the MODIS enhanced vegetation index (EVI) and respiration directly from MODIS surface temperature (MOD11). Carbon flux data were obtained from 10 eddy covariance tower sites representing a wide range of North American vegetations. The correlation between across-site tower GPP and EVI was comparable (r = 0.77) to that between tower GPP and MOD17-GPP (r = 0.73), suggesting that EVI could be used to provide reasonably accurate direct estimates of GPP on a truly per-pixel basis. There was also a strong relationship (r2 = 0.67) between respiration and …
Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul
Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23 - 31° N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information.