Showing papers by "National Ocean Service published in 2003"
TL;DR: In this article, the authors developed an empirical solution using a ratio of reflectances that has only two tunable parameters and can be applied to low-albedo features, which can compensate for variable bottom type and albedo (sand, pavement, algae, coral).
Abstract: A standard algorithm for determining depth in clear water from passive sensors exists; but it requires tuning of five parameters and does not retrieve depths where the bottom has an extremely low albedo. To address these issues, we developed an empirical solution using a ratio of reflectances that has only two tunable parameters and can be applied to low-albedo features. The two algorithms—the standard linear transform and the new ratio transform— were compared through analysis of IKONOS satellite imagery against lidar bathymetry. The coefficients for the ratio algorithm were tuned manually to a few depths from a nautical chart, yet performed as well as the linear algorithm tuned using multiple linear regression against the lidar. Both algorithms compensate for variable bottom type and albedo (sand, pavement, algae, coral) and retrieve bathymetry in water depths of less than 10‐15 m. However, the linear transform does not distinguish depths .15 m and is more subject to variability across the studied atolls. The ratio transform can, in clear water, retrieve depths in .25 m of water and shows greater stability between different areas. It also performs slightly better in scattering turbidity than the linear transform. The ratio algorithm is somewhat noisier and cannot always adequately resolve fine morphology (structures smaller than 4‐5 pixels) in water depths .15‐20 m. In general, the ratio transform is more robust than the linear transform.
749 citations
TL;DR: There is a rapidly advancing monitoring effort resulting from the perception of increased impacts from these HABs, manifested as expanding routine coastal monitoring programs, rapid development and deployment of new detection methods for individual species, toxins, and toxicities, and expansion of coastal modeling activities towards observational forecasts of bloom landfall and eventually bloom prediction.
Abstract: Blooms of autotrophic algae and some heterotrophic protists are increasingly frequent in coastal waters around the world and are collectively grouped as harmful algal blooms (HABs). Blooms of these organisms are attributed to two primary factors: natural processes such as circulation, upwelling relaxation, and river flow; and, anthropogenic loadings leading to eutrophication. Unfortunately, the latter is commonly assumed to be the primary cause of all blooms, which is not the case in many instances. Moreover, although it is generally acknowledged that occurrences of these phenomena are increasing throughout the world's oceans, the reasons for this apparent increase remain debated and include not only eutrophication but increased observation efforts in coastal zones of the world. There is a rapidly advancing monitoring effort resulting from the perception of increased impacts from these HABs, manifested as expanding routine coastal monitoring programs, rapid development and deployment of new detection methods for individual species, toxins, and toxicities, and expansion of coastal modeling activities towards observational forecasts of bloom landfall and eventually bloom prediction. Together, these many efforts will provide resource managers with the tools needed to develop effective strategies for the management and mitigation of HABs and their frequently devastating impacts on the coastal environment.
516 citations
TL;DR: In this paper, an integrated methodology for the assessment of estuarine trophic status (ASSETS) is described, which may be applied comparatively to rank the eutrophication status of the estuaries and coastal areas, and to address management options.
435 citations
TL;DR: The Gulf of Mexico Harmful algal blooms (HABs) of Karenia brevis are a recurrent problem in the Gulf of the USA as discussed by the authors, with nearly annual occurrences on the Florida southwest coast and fewer occurrences on northwest Florida and Texas coasts.
313 citations
TL;DR: Comparing the relationships among the specific growth rate, intracellular iron content, and steady state iron uptake rate for cultures of the marine diazotrophic cyanobacterium Trichodesmium grown under differing conditions of Fe and N availability suggest that Fe limitation is more prevalent in the Australia Trichodemium populations, while P limitation predominates in the Atlantic populations.
Abstract: We quantified the relationships among the specific growth rate, intracellular iron content, and steady state iron uptake rate for cultures of the marine diazotrophic cyanobacterium Trichodesmium (IMS 101) grown under differing conditions of Fe and N availability. The Fe quotas necessary to support a moderately Fe-limited growth rate (70% mmax) of 0.1 d−1 under diazotrophy and ammonium were 38 and 8 µmol mol−1, indicating a fivefold increased Fe cost for diazotrophy. This increased demand reflects the influences of both the ninefold lower marginal use efficiency and the greater maintenance Fe :C requirement at zero growth rate under diazotrophy (13.5 versus 5.2 µmol mol−1). For diazotrophic growth at µ = 0.1 d−1, we estimate that 19%–53% of the cellular Fe is bound in nitrogenase. Trichodesmium is capable of luxury uptake of at least 13-fold greater amounts of Fe than needed for moderately Fe-limited growth. At least half of the populations sampled from the continental shelf of northern Australia had Fe :C ratios within the range of iron limitation of laboratory cultures. Bottle incubations showed that, after 3–4 d with added iron, a low Fe :C population (21 µmol mol−1) had higher N2 fixation rates than controls, whereas a high Fe :C population (78 µmol mol−1) showed no response. The cellular N: P quotas and N2 fixation rates were compared to those previously reported for the Atlantic Ocean. Empirically, these data suggest a critical N: P ratio ~40–50 for the onset of P limitation of growth. Only 10% of the Trichodesmium populations from coastal Australia had N: P ratios within the putative P-limitation range (>40), whereas 40% the Atlantic populations fell within this range. These comparisons, along with those for N fixation versus colony Fe :C ratio, suggest that Fe limitation is more prevalent in the Australia Trichodesmium populations, while P limitation predominates in the Atlantic populations.
189 citations
TL;DR: These PCR assays had a minimum sensitivity of 100 cells in a 100‐mL sample and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
Abstract: The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida (Steidinger et Burkholder), frequently co-occurs with other morphologically similar species collectively known as Pfiesteria -like organisms (PLOs). This study specifically evaluated whether unique sequences in the internal transcribed spacer (ITS) regions, ITS1 and ITS2, could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit or large subunit rRNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida , Pfiesteria shumwayae (Glasgow et Burkholder), Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum (Leadbetter et Dodge). These PCR assays had a minimum sensitivity of 100 cells in a 100-mL sample (1 cell·mL � 1 ) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA. DNA purification and aspects of PCR assay development, PCR optimization, PCR assay controls, and collection of field samples are discussed.
125 citations
TL;DR: The results demonstrate the importance of nutrient limitation in enhancing DMSP concentrations in marine algae and may be linked in part to the role of DMSP as a cellular antioxidant and to increased oxidative stress within cells during nutrient limitation.
Abstract: We measured intracellular dimethyl sulfoniopropionate (DMSP) concentrations in nutrient-limited batch cultures of the coastal diatom Thalassiosira pseudonana. Under N, P, CO2, and Si growth limitation, intracellular DMSP concentrations decreased to low values during the exponential phase of growth and increased under nutrient limitation. The intracellular DMSP concentration increased exponentially with decreasing growth rate and cellular chlorophyll a, in response to the type and degree of nutrient limitation. For a given growth rate, N-limited cells showed the greatest increase in cellular DMSP concentrations, CO2 and Si limitation had an intermediate effect, and P limitation caused the smallest increase. The results demonstrate the importance of nutrient limitation in enhancing DMSP concentrations in marine algae. This enhancement may be linked in part to the role of DMSP as a cellular antioxidant and to increased oxidative stress within cells during nutrient limitation. The replacement of DMSP, a sulfur-containing osmolyte, for N-containing osmolytes such as proline may also explain at least some of the DMSP increase under N limitation. Our results also point to the possible importance of diatom blooms in global or regional sulfur cycles.
120 citations
TL;DR: Results indicate that photosynthetic tolerance to higher irradiances and presence of UV-absorbing pigments (UVP) in H. johnsonii may allow this species to exploit the shallowest waters without competition from the closely related, but UVP-lacking H. decipiens.
Abstract: The threatened seagrass Halophila johnsonii Eiseman coexists subtidally with H. decipiens Ostenfeld in southeastern Florida, but only H. johnsonii also oc- curs intertidally. Pulse amplitude modulated fluorome- try and fiber-optic spectrometry were used to investigate the photobiology of two populations of H. johnsonii and H. decipiens in an attempt to explain these distribution patterns. Maximum photosynthetic quantum yields (Fv/ Fm) were measured in situ as a function of depth dis- tribution within, and between, these two species at two sites (Jupiter Sound, 26� 57¢N; 80� 04¢W, and northern Biscayne Bay, 25� 55¢N; 80� 07¢W) along the east coast of Florida, USA, during 6-10 March 2001. Reciprocal transplants at the northern site were used to evaluate the plasticity of photosynthetic patterns and pigment absorption spectra and to gain insights into the mecha- nisms responsible for variations in the observed depth- distribution patterns. Subtidal-population Fv/Fm values were generally higher for H. johnsonii than for H. deci- piens, at both sites. At the northern site, intertidal H. johnsonii had significantly lower Fv/Fm (0.494±0.138) than both subtidal H. johnsonii (0.696±0.045) and subtidal H. decipiens (0.668±0.048). In contrast, at the southern site intertidal H. johnsonii had the highest Fv/ Fm (0.663±0.047) and were the largest plants. Fv/Fm values of subtidal plants of both species decreased when they were transplanted into shallow, intertidal beds. Correspondingly, Fv/Fm increased for intertidal H. johnsonii transplanted into the subtidal, 2 m deep beds. Rapid light curves indicated that H. decipiens had lower maximum relative electron transport rates (RE- TRmax) than did H. johnsonii. In addition, the onset of photoinhibition occurred at lower irradiances for H. decipiens (537-820 lmol photons m )2 s )1 ) compared to H. johnsonii (1141-2670 lmol photons m )2 s )1 ). RETRmax values decreased for intertidal H. johnsonii transplanted into subtidal beds, but they increased for both species when transplanted from subtidal to inter- tidal beds. Absorption spectra for the acetone-soluble leaf pigments of intertidal H. johnsonii exhibited a dominant peak near 345 nm; this UV peak was 30% lower for subtidal plants. Pigment absorption spectra for H. decipiens lacked the 345 nm peak and absorbances, normalized to leaf pairs, were lower across the spectrum. Our results indicate that photosynthetic tolerance to higher irradiances and presence of UV-absorbing pig- ments (UVP) in H. johnsonii may allow this species to exploit the shallowest waters without competition from the closely related, but UVP-lacking H. decipiens.
73 citations
64 citations
TL;DR: Condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors in estuaries along the U.S. Atlantic and Gulf of Mexico coasts.
Abstract: Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).
63 citations
TL;DR: Measurements of gyroxanthin‐diester and other diagnostic pigments of Karenia brevis were incorporated into the initial pigment ratio matrix of the chemical taxonomy program (CHEMTAX) to resolve the relative contribution of K. brevis biomass in mixed estuarine phytoplankton assemblages from Florida and Galveston Bay, Texas.
Abstract: Diagnostic photopigment analysis is a useful tool for determining the presence and relative abundance of algal groups in natural phytoplankton assemblages. This approach is especially useful when a genus has a unique photopigment composition. The toxic dinoflagellate Karenia brevis (Davis) G. Hansen & Moestrup comb. nov. shares the diagnostic pigment gyroxanthin-diester with only a few other dinoflagellates and lacks peridinin, one of the major diagnostic pigments of most dinoflagellate species. In this study, measurements of gyroxanthin-diester and other diagnostic pigments of K. brevis were incorporated into the initial pigment ratio matrix of the chemical taxonomy program (CHEMTAX) to resolve the relative contribution of K. brevis biomass in mixed estuarine phytoplankton assemblages from Florida and Galveston Bay, Texas. The phytoplankton community composition of the bloom in Galveston Bay was calculated based on cell enumerations and biovolumetric measurements in addition to chl a-specific photopigment estimates of biomass (HPLC and CHEMTAX). The CHEMTAX and biovolume estimates of the phytoplankton community structure were not significantly different and suggest that the HPLC–CHEMTAX approach provides reasonable estimates of K. brevis biomass in natural assemblages. The gyroxanthin-diester content per cell of K. brevis from Galveston Bay was significantly higher than in K. brevis collected from the west coast of Florida. This pigment-based approach provides a useful tool for resolving spatiotemporal distributions of phytoplankton in the presence of K. brevis blooms, when an appropriate initial ratio matrix is applied.
TL;DR: A comparative study of the binding properties and the cytotoxic effects of ciguatoxins and brevetoxins on human embryonic cells (HEK) stably expressing either the skeletal muscle, or the cardiac sodium channel alpha-subunit isoforms.
TL;DR: In this paper, an adjoint data assimilation system which assimilates predicted coastal tidal elevations into a two-dimensional Princeton Ocean Model for the East Coast of the United States is proposed.
TL;DR: Normal-phase high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) allows qualitative analysis of endogenous ceramide and dihydroceramide species from crude lipid extracts utilizing chromatographic methods readily adaptable from commonly used thin layer chromatography (TLC) conditions.
Abstract: Normal-phase high-performance liquid chromatography (NP-HPLC) coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) allows qualitative analysis of endogenous ceramide and dihydroceramide species from crude lipid extracts utilizing chromatographic methods readily adaptable from commonly used thin layer chromatography (TLC) conditions. Qualitative information for the species comes from observation of differences in chromatographic and mass spectrometric behavior between species. Application to the analysis of ceramide and dihydroceramide from various cell lines is demonstrated. The results show the species profile in each cell line to be unique despite growth under identical conditions. The results from APCI-MS analysis corroborate and enhance information acquired from use of the diacylglycerol kinase assay for total ceramide measurement. This technique readily allows the previously difficult distinction between ceramide and dihydroceramide species.
01 Sep 2003-Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes
TL;DR: It is demonstrated that chlorothalonil is highly toxic to grass shrimp and that larval grass shrimp would be the most appropriate life stage to use for chlorothsalonil risk assessments since that stage is the most sensitive.
Abstract: Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) is the second most widely used fungicide in the United States. Due to the widespread use of chlorothalonil, it is important to investigate the effects chlorothalonil may have on estuarine species such as the grass shrimp, Palaemonetes pugio. This study examined the toxicity of chlorothalonil to three life-history stages (embryo, larvae, adult) of the grass shrimp. Also, molting frequency, growth response and metamorphosis from a larval life cycle pulsed exposure assay were examined as sub-lethal indicators of chlorothalonil exposure. Results showed embryos were the least sensitive with a 96-h Median Lethal Concentration (LC50) of 396.0 microg/L (95% Confidence Interval [CI] 331.3-472.4 microg/L). The adult 96-h LC50 was 152.9 microg/L (95% CI 120.3-194.5 microg/L). Larvae were the most sensitive to chlorothalonil exposure with a 96-h LC50 of 49.5 microg/L (95% CI 44.4-55.27 microg/L). In the life cycle pulsed exposure assay, all surviving larvae in the treatments required significantly more molts to reach postlarvae than the control. Other measured parameters showed differences between treatments and control but there was no statistical significance. This research demonstrated that chlorothalonil is highly toxic to grass shrimp and that larval grass shrimp would be the most appropriate life stage to use for chlorothalonil risk assessments since that stage is the most sensitive.
TL;DR: In this article, airborne laser-induced fluorescence measurements were used to detect and monitor ecosystem wide changes in the distribution and concentration of chlorophyll biomass and colored dissolved organic matter in the Pamlico-Albemarle Sound system, North Carolina, U.S., following massive flooding caused by a series of three hurricanes in the late summer of 1999.
Abstract: Airborne laser-induced fluorescence measurements were used to detect and monitor ecosystem wide changes in the distribution and concentration of chlorophyll biomass and colored dissolved organic matter in the Pamlico-Albemarle Sound system, North Carolina, U.S., following massive flooding caused by a series of three hurricanes in the late summer of 1999. These high-resolution data provided a significantly more detailed representation of the overall changes occurring in the system than could have been achieved by synoptic sampling from any other platform. The response time for the distribution of chlorophyll biomass to resume pre-flood conditions was used as a measure of ecosystem stability. Chlorophyll biomass patterns were reestablished within four mo of the flooding, whereas higher chlorophylla biomass concentrations persisted for approximately 6 mo. The primary trophic level in the Pamlico-Albemarle Sound system returned to equilibrium in less than a year of a major perturbation.
TL;DR: This study evaluated PST production by two bacterial strains, isolated previously from toxic dinoflagellates, using biological and analytical methods to challenge previous findings.
Abstract: Paralytic shellfish toxins (PSTs) are potent neurotoxins produced by certain dinoflagellate and cyanobacterial species. The autonomous production of PSTs by bacteria remains controversial. In this study, PST production by two bacterial strains, isolated previously from toxic dinoflagellates, was evaluated using biological and analytical methods. Analyses were performed under conditions determined previously to be optimal for toxin production and detection. Our data are inconsistent with autonomous bacterial PST production under these conditions, thereby challenging previous findings for the same strains.
TL;DR: In this article, a new method of estimating total water levels relative to a datum is proposed, called tidal constituent and residual interpolation (TCARI), which takes values at the tide gauges and spatially interpolates them throughout the region.
TL;DR: This unusual behavior of the cyclin B homologue in dinoflagellates, its relationship to the unusual characteristics of dinomitosis, and its potential implications regarding the evolution of cell cycle regulation among eukaryotes are discussed.
Abstract: The eukaryotic cell cycle is driven by a set of cyclin-dependent kinases associated with their regulatory partners, the cyclins, which confer activity, substrate specificities and proper localization of the kinase activity. We describe the cell cycle of Karenia brevis and provide evidence for the presence of a cyclin B homologue in this dinoflagellate using two antibodies with different specificities. This cyclin B homologue has an unusual behavior, since its expression is permanent and it has a cytoplasmic location throughout the cell cycle. There is no evidence for translocation to the nucleus during mitosis. However, it appears also to be specifically bound to the nucleolus throughout the cell cycle. The permanent expression and the cytoplasmic localization during mitosis of this cyclin B homologue is similar to p56, a cyclin B homologue previously described in a different species of dinoflagellate, Crypthecodinium cohnii. Here we discuss this unusual behavior of the cyclin B homologue in dinoflagellates, its relationship to the unusual characteristics of dinomitosis, and its potential implications regarding the evolution of cell cycle regulation among eukaryotes.
TL;DR: The extent of toxin variation resulting from differing gonad preparations demonstrates the need to standardize scallop tissue preparation techniques during ASP events and detailed protocols aimed at minimizing the contamination of edible components should be developed and adhered to by both processing facilities and monitoring bodies.
TL;DR: A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America as mentioned in this paper.
Abstract: [1] A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March (dry season) and June (wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated in the portion of the estuary that has open communication with the ocean. During the dry season, water exchange at the entrance to the gulf suggested an inverse estuarine circulation that was more robust, and its dynamics were closer to geostrophy during neap than during spring tides. It is likely that salinity increased toward the tributaries of the system and then decreased within those tributaries because of the persistent influence of fresh water. In contrast, during the wet season, salinity decreased into the estuary, and the circulation resembled that of a typical estuary. In this season the fortnightly modulation of exchange flows was masked by wind effects, which also played a relevant role in the dynamics. The net volume inflows measured in both seasons suggested that the residence time of the Gulf of Fonseca varies from 2 weeks to 1 month.
TL;DR: This model has demonstrated the cause-and-effect relationship between exposure to a hydrophilic toxin produced by P. piscicida and learning impairment, and specifically that the ventral hippocampus was critically involved.
TL;DR: Velvet bean does not appear to be suitable as an organic mulch for fall collard production, but could be used as a summer cover crop if disked into the soil before transplanting collard.
Abstract: Velvet bean has been used traditionally as a summer cover crop in the southeastern United States. We investigated the use of killed velvet bean as a cover crop mulch left on the soil surface before collard was transplanted in the fall. Control treatments were weed-free fallow and velvet bean that was killed and disked into the soil before transplanting. Incidence of wirestem, caused by Rhizoctonia solani, reached a maximum of 25% in 2000 but only 4% in 2001 in cover crop mulch treatments. Nevertheless, in both years, the infection rate, area under the disease progress curve, and final incidence were significantly greater with cover crop mulch than in the fallow or disked treatments. Wirestem incidence did not differ between the disked and fallow treatments in either year. Populations of R. solani in soil were greater after cover crop mulch than in fallow plots in both years and greater in the disked treatment than in fallow soil in 2000 but not 2001. Velvet bean does not appear to be suitable as an organic mulch for fall collard production, but could be used as a summer cover crop if disked into the soil before transplanting collard.
TL;DR: These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
Abstract: The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida, frequently co-occurs with other morphologically similar species collectively known as Pfiesteria-like organisms (PLOs). This study specifically evaluated whether unique sequences in the ribosomal internal transcribed spacer regions (ITS1 and ITS2) could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit (SSU) or large subunit (LSU) ribosomal RNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida, Pfiesteria shumwayae, Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum. These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
TL;DR: In this article, the authors present calibration results from Jason-1 and TOPEX/Poseidon overflights of dedicated verification sites on the Mediterranean island of Corsica and on a California offshore oil platform (Harvest).
01 Sep 2003
TL;DR: For example, National VDatum as mentioned in this paper is a vertical datum transformation tool that allows transformation of bathymetric and topographic elevation among 28 different orthometric, ellipsoid/3-D, and tidal datums.
Abstract: NOS/NOAA has developed a vertical datum transformation tool, VDatum, which allows transformation of bathymetric and topographic elevation among 28 different orthometric, ellipsoid/3-D, and tidal datums. This tool is based on the latest geoid, ellipsoid, and tidal hydrodynamic models. A national vertical datum transformation database ("National VDatum") is being developed and populated by NOS, and a major effort remaining is the tidal modeling of every bay and estuary in the US, plus some refinements of the geoid model in Alaska. The use of VDatum will be a cornerstone of the new way that NOS will acquire, handle and process bathymetric and shoreline data and efficiently use these data to produce NOAA nautical chart and electronic vector products and to support coastal resource managers. Some applications for which National VDatum is critical include: (1) the sharing of geospatial data among NOAA, USGS, FEMA, NIMA, and other federal and state agencies, which datum incompatibilities have limited in the past; (2) the implementation of a full National Bathy/Topo Program with the U.S. Geological Survey, VDatum being required for the blending of NOAA's bathymetric data with USGS's topographic data; (3) the measurement of consistently defined MHW shoreline from RTK-GPS-referenced Lidar elevation data from the intertidal zone, transformed with VDatum to the MHW datum, with the zero line then being the shoreline; (4) meeting local coastal user needs for being able to blend their bathymetric and topographic data with that obtained by other groups; local users are requesting a National VDatum for this reason; (5) the implementation of a seamless National Bathymetric Database, using VDatum to transform all historical data sets to a common datum (MLLW); (6) improving the efficiency and accuracy of RTK-GPS-referenced hydrographic surveys by eliminating the need for simultaneous tide installations, settlement/squat corrections, and time-consuming post processing; (7) the ability to use high-quality 3/sup rd/-party bathymetric data in NOAA nautical chart products, with VDatum solving the datum incompatibility problems that have prevented this; (8) marine boundary applications; and (9) the ability to link with creation of GIS layers and digital elevation models required for habitat restoration projects.
TL;DR: The real-time Port of New York and New Jersey Operational Forecast System (NYOFS) became operational on 10 February 2003 at NOAA's National Ocean Service (NOS) in Silver Spring, Maryland.
Abstract: he real-time Port of New York and New Jersey Operational Forecast System (NYOFS) became operational on 10 February 2003 at NOAA’s National Ocean Service (NOS) in Silver Spring, Maryland. NYOFS generates hourly nowcasts and hourly forecast guidance out to 30 hours of currents and water levels for the Port region, including Raritan Bay, Newark Bay, and Upper Bay, the Kill Van Kull, Arthur Kill, the lower Hudson River, and the East River. NYOFS graphical products—including time series, maps, and animations of water levels and currents, nowcasts, and forecast guidance—are disseminated through an NOS Web site (http://co-ops.nos.noaa.gov/ NYOFS/nyofs.shtml). The model predictions are displayed as a graph of the water-level height and current velocity at measurement stations and other locations throughout the bay (Fig. 1). The system has been incorporated into NOS’s Physical Oceanographic Real-Time System (PORTS®), which provides an operational monitoring system (24 hours a day, 7 days a week) for quality assurance and control of the NYOFS inputs, operational procedures, and product dissemination. Historically, mariners navigating in New York Harbor have used NOAA’s tide and tidal current tables for the best estimate of expected water levels and currents. However, these tables cannot predict changes due to wind, atmospheric pressure, and river flow, which are often significant (Fig. 2). Furthermore, the tide water level and tidal current predictions are available at only a few locations. Although new technology, such as PORTS, at selected locations maintained by NOS provides near-real-time information to the users, there is still need for more information for assuring navigation safety. These include 1) near-real-time water level and current information at locations without gauges, 2) shortterm (1–2 days) water level and current forecast guidFig. 1. NYOFS nowcast/forecast guidance locations.
01 Nov 2003
TL;DR: In this article, the authors have made advances in three areas: algorithm development (Table 16.1), field data collection, and data applications for SeaWiFS in the coastal zone.
Abstract: SeaWiFS has the ability to enhance our understanding of many oceanographic processes. However, its utility in the coastal zone has been limited by valid bio-optical algorithms and by the determination of accurate water reflectances, particularly in the blue bands (412-490 nm), which have a significant impact on the effectiveness of all bio-optical algorithms. We have made advances in three areas: algorithm development (Table 16.1), field data collection, and data applications.