Search

Vessel handling guidelines in Tampa Bay have been developed and refined over many years to prevent vessel groundings, collisions, and other maritime incidents. These guidelines restrict nav...

Tampa Bay, FL, is a large, ecologically rich estuary that hosts one of the largest commercial ports in Florida. Automatic identification system (AIS) records from 2015 to 2017 were used to...

Ocean observing stations have mainly focused on data collection of physical parameters measured in the ocean and atmosphere and also, to some extent, of biogeochemical parameters. Robust sensors capable of measuring biological data reflective of higher tropic level function at the same time scales as other parameters are not yet commonly incorporated into the sensor array used on observing platforms. In this project, we reengineered a coastal ocean observatory to include two hydrophones for this purpose. One hydrophone (HTI 96-MIN) was used to record ambient acoustic signals of fish reproductive sounds, and a second hydrophone (Vemco VR2C) was used to receive transmissions from acoustic tags implanted in fishes. This project demonstrates that it is possible at a regional ocean observing station to collect data on biological-physical processes at the same time scales over long periods and on a cost-effective basis. This will allow a better understanding of natural variability in ecosystem processes and potential impacts on these from anthropogenic sources and climate change. Technical details of the reengineering methods used to make the station operational and URLs of data tables and archives are provided.

Ship wakes generated by vessels moving through ecologically sensitive areas, or near poorly-protected infrastructure, can negatively impact these systems. This is especially true in regions hosting large seaports. Ship wakes in Tampa Bay, Florida, were calculated during two time periods using vessel movement data reported through the Automatic Identification System (AIS). The first period was for the years 2015–2017 using data from a government database. The second was during part of 2018 obtained by local monitoring. Only vessels operating at low Froude numbers were examined. Wake heights were estimated from each AIS record using an empirical equation and partitioned by functional vessel class. The largest estimated wakes were produced by the Passenger class. Cargo class vessels had the largest number of ships estimated to produce high wakes. Egmont Key, a long-eroding barrier island at the mouth of the Bay, was potentially subjected to the highest number of ship wakes and the highest cumulative wake energy. Differences in vessel representation in the two sets of AIS data yielded different distributions of wake energy by vessel class. Some strategies for managing wake energy are discussed.

The eastern oyster Crassostrea virginica once supported one of the largest fisheries in the eastern United States. Oyster populations and the reefs they form have suffered chronic long-term decline throughout the species' range, including in northwest Florida's Pensacola Bay estuary system (PBS). To guide efforts to rebuild oyster populations in the PBS, connectivity patterns were evaluated among historic and extant reef locations using an integrated biophysical numerical model. Water quality parameters and oyster recruitment were monitored in May 2007 and then monthly from July 2007 through July 2008. Resultant salinity data were used to calibrate an Estuarine Coastal Ocean Model—based numerical circulation model of Pensacola Bay, which was then coupled to an existing, individual-based, oyster larvae routine to predict ontogenetic larval distribution. Threedimensional Lagrangian transport algorithms were used to simulate transport of modeled larvae during four 20-day time periods during those su...

Coastal wastewater and storm water systems can be overwhelmed during high precipitation events, particularly when compounded by high storm surge that blocks spillways and drainage ways. Sea level rise (SLR) brings increased risk of such compound flooding events, triggering sanitary sewer overflows (SSO) which release waste water into the local environment. A logistic regression model was developed to better predict this risk in southern Pinellas County, FL. Model variables were selected from 2000 to 2017 cumulative precipitation and coastal water levels using both objective and subjective criteria. The 2 day (P2) and 90 day (P90) cumulative precipitation, and 2 day water level maximum (W2) were identified as significant predictors from the p-value of their model coefficients, but required an interaction term P2*W2 for model fidelity. The model correctly hindcasted all 6 identified SSOs from 2000 to 2017. SLR was represented by a range of values up to 0.5 m added to W2. For a SLR of 0.5 m the number of SSO days increased by a factor of 42–52 and the number of individual events increased by a factor of ~15. Subtracting recent SLR from W2 reduced the probability of some recent events, suggesting that SLR already is increasing the rate of SSOs.

The shoreline around Tampa Bay, Florida contains large areas of productive habitat, hosting some of the highest concentrations of wading birds in the US. The bay also contains one of the busiest seaports in the country. Thousands of transits by large vessels such as tankers, cargo ships, and cruise liners are recorded every year through the network of shipping channels within the bay. Their wakes potentially threaten critical shoreline habitat as well as increased erosion around infrastructure and property. Vessel wake heights for the bay were estimated from records of vessel length, draught, and speed extracted from the historical Automatic Identification System (AIS) data. Errors in these data such as unrealistic draught and speed were removed from the analysis. This initial study was limited to the year 2015 and vessel lengths greater than 30 m. Over 560 of these vessels, composed of 26 unique vessel types, passed through Tampa Bay for a total of ~6000 transits. These ships range in size from 30-300 m in length with maximum draughts around 15 m. Ship wake heights were computed using the empirical relation developed for displacement vessels by Kriebel and Seelig (2005) based on the Froude number. Almost all the estimated wake heights were 0.5m.

The first NOAA Physical Oceanographic Real-Time System (PORTS®) was established in Tampa Bay, Florida, becoming operational in 1991 (https://tidesandcurrents.noaa.gov/ports/index.shtml?port=tb). In April 2018, the Miami Physical Oceanographic Real-Time System was dedicated as the 30th such system in the US, followed closely by Port Everglades PORTS® in June 2018 as the 31st. PORTS® collects and disseminates real time meteorological and oceanographic data within major harbors around the US. PORTS® data are an essential component for maintaining the safety and efficiency of maritime operations. Before the advent of PORTS®, knowledge of environmental conditions relevant to ship operations in US harbors was generally limited to wind and precipitation sensors at the local airports and similar shipboard instrumentation. Water levels were inferred from standard tide tables even though surface winds were known to produce significant deviations from predicted values. This incomplete knowledge often led to navigational errors and to accidents. This paper will review the history of PORTS® development, highlighting recent advances in sensor technologies and novel uses of PORTS® data.On May 9, 1980, the 580 foot, 20,000 ton bulk carrier Summit Venture was approaching a critical turn toward the Sunshine Skyway Bridge in Tampa Bay, Florida and was overtaken by a violent, blinding thunderstorm. The ship veered off course and crashed into a main support pier of the bridge, collapsing the southbound span. Thirty-six people in vehicles fell into the water; 35 did not survive. The main ship channel into Tampa Bay port facilities was closed for 6 weeks, causing severe disruption to supplies of fuel and other commodities to the entire central Florida region. In the wake of the disaster, the local maritime community, led by the Tampa Bay Pilots Association and the Tampa Port Authority, petitioned the US Congress for funding to the National Oceanic and Atmospheric Administration to improve environmental monitoring capabilities in the bay. Nearly a decade later, the Tampa Bay Oceanography Project (TOP) began in 1990 as part of NOAA’s Coastal Ocean Circulation Program (COCP). This included a 15 month study of currents, water levels, water temperatures, salinity, winds, and other meteorological/oceanographic parameters. By the end of the project, TOP had collected the largest number of circulation measurements in one estuary in the 100-year history of COCP.Successful completion of TOP was followed by permanent deployment of real-time telemetered sensors measuring winds, currents, and water levels at critical locations in the bay - the first official NOAA PORTS® installation. Since 1991, local operations and maintenance of the system have been directed by the Greater Tampa Bay Marine Advisory Council-PORTS, Inc., a non-profit consortium of maritime interests, through cooperative agreements with the NOAA National Ocean Service Center for Operational Products and Services and the University of South Florida Center for Maritime and Port Studies.The success of TB-PORTS made it a prototype for a national program. Within three years of TB-PORTS becoming operational, San Francisco Bay and Houston/Galveston Bay implemented their own PORTS® networks. Today PORTS® operates 24 hours a day/7 days a week in 31 locations around the coasts and Great Lakes of the United States and is a component of the Integrated Ocean Observing System national backbone. The local operation and maintenance of PORTS® facilities in each port remains funded by local maritime interests under the direction of NOAA/NOS/CO-OPS, who sets operational standards and manages the data quality control and dissemination through the Continuous Operational Real-Time Monitoring System (CORMS).PORTS® data are provided to the public through the NOAA websitehttp://tidesandcurrents.noaa.gov/ports.html. A prototype project in Tampa Bay provides PORTS® data to pilots aboard ships over the Automatic Identification System (AIS), now required on all commercial vessels over 20 m in length, in collaboration with the US Coast Guard R&D Center. The long time series observations of winds, currents, water levels, and other parameters in Tampa Bay from PORTS® has fueled numerous scientific studies on the dynamics of the estuary. New sensor technologies have been incorporated into the PORTS® data stream in recent years, including wave height, period, and direction, atmospheric visibility, and most recently, current measurements from sensors mounted on standard US Coast Guard aids to navigation buoys.

Warming ocean currents are considered to be a contributing factor to the retreat of marine-terminating glaciers worldwide, but direct observations near the ice-ocean interface are challenging. We use radar intensity imagery and an iceberg tracking algorithm to produce half-hourly current maps within an imaged portion of Jokulsarlon, a proglacial lagoon in southeastern Iceland. Over our 43.5-h observation period, the lagoon has clockwise circulation with current speeds of order 3-8cm/s and occasional strong glacier outflows of up to ~15cm/s. The currents driven by the glacial outflows appear to be dominantly inertial. HighlightsWe track iceberg motion in a glacial lagoon using terrestrial radar intensity images.We use a PTV approach to track the icebergs.We interpolate the currents using radial basis functions.Subglacial outflows contribute to inertial circulation in the lagoon.

The co-occurrence of storm surge and heavy precipitation can compound coastal flooding. Research now estimates the probability of such co-occurrences for the US and shows that the number of events has increased significantly over the past century.

A nonlinear relation between the salinity field and the subtidal exchange circulation in the Tampa Bay estuary is demonstrated using observational data from 1999 to 2011. The data are averaged to form mean monthly climatological values of total freshwater discharge ( Q), axial and vertical salinity gradients, and subtidal vertical shear. Well-known steady state solutions indicate that the exchange circulation is linearly proportional to the horizontal salinity gradient, assuming a constant vertical eddy viscosity ( Aeff). The exchange flow is found to be multivalued with respect to the horizontal salinity gradient, forming a hysteresis loop in parameter space that passes through three dynamical regimes. Regime I is relatively dry with weak salinity gradients and exchange circulation. Regime II is the wet season (June–September) in which all quantities rapidly increase. In regime III, the exchange flow persists even though Q and the axial salinity gradient are again low. Gradient Richardson numbers and Simpson numbers also form a loop in parameter space with Ri remaining subcritical (turbulent) until the wet season when Ri rises above criticality (weak vertical mixing) where it remains through the end of regime III. The Simpson number is in a narrow range around 0.2, indicating that the horizontal salinity gradient is always a driver of the exchange circulation. The Aeff, estimated from a parameterization of the Richardson number, decreases by almost an order of magnitude from regimes I to II. It remains low during III, indicating that the persistent stratification is insulating the exchange flow from destruction by tidal mixing during this time period.

The need for a statutory framework to manage valuable marine resources in the United States is highlighted by problems such as fragmented ocean governance and increasing conflict over the use of ocean spaces. On July 19, 2010 President Obama signed Executive Order 13547 to create a National Ocean Policy (NOP) for the United States. A subsequent Implementation Plan, released in 2013, set up hundreds of actions to be accomplished between 2013 and 2025 to address economic, community, scientific and other issues. Progress implementing the NOP appears to have stalled. The purpose of this paper is to give an overview of the NOP and its Implementation Plan, and then discuss what needs to be done to bring the vision it set forth to fruition.

Temporal variations of the seasonal sea level harmonics throughout the 20th and early 21st century along the United States Gulf coast are investigated. A significant amplification of the annual sea level cycle from the 1990s onward is found, with both lower winter and higher summer sea levels in the eastern Gulf. Ancillary data are used to build a set of multiple regression models to explore the mechanisms driving the decadal variability and recent increase in the annual cycle. The results suggest that changes in the air surface temperature toward warmer summers and colder winters and changes in mean sea level pressure explain most of the amplitude increase. The changes in the seasonal sea level cycle are shown to have almost doubled the risk of hurricane induced flooding associated with sea level rise since the 1990s for the eastern and north-eastern Gulf of Mexico coastlines.

Large-scale human-built infrastructure is shown to alter the salinity and subtidal residual flow in a realistic numerical simulation of hydrodynamic circulation in a coastal plain estuary (Tampa Bay). Two model scenarios are considered. The first uses a modern bathymetry and boundary conditions from the years 2001–2003. The second is identical to the first except that the bathymetry is based on depth soundings from the pre-construction year 1879. Differences between the models' output can only result from changes in bay morphology, in particular built infrastructure such as bridges, causeways, and dredging of the shipping channel. Thirty-day means of model output are calculated to remove the dominant tidal signals and allow examination of the subtidal dynamics. Infrastructure is found to steepen the mean axial salinity gradient $$ \partial \overline{s}/ dx $$ by ~40% when there is low freshwater input but flatten $$ \partial \overline{s}/ dx $$ by ~25% under more typical conditions during moderate freshwater inflow to the estuary. Deepening of the shipping channel also increases the magnitude of the residual Eulerian circulation, allowing for larger up-estuary salt transport. Local bathymetry and morphology are important. Some regions within the estuary show little change in residual circulation due to infrastructure. In others, the residual circulation can vary by a factor of 4 or more. Major features of the circulation and changes due to infrastructure can be partially accounted for with linear theory.

Given the societal importance of reliable and accurate ocean observations, the wave monitoring community (including academic researchers, agency scientists, resource managers, and representatives from wave instrument manufacturers) came together to develop a set of protocols for the test and evaluation of wave measurement systems in support of the 2009 National Operational Wave Observation Plan. These protocols are focused on a wide range of wave measurement instruments and their respective performance in successfully recovering the “First-5” Fourier components of the incident wave field. Performance is determined by comparing each system’s output with a verifiable reference method over a predetermined range of wave frequencies. It is recommended that permanent wave test facilities are created on the West Coast (Monterey Bay, CA—deep water) and the East Coast (Duck, NC—shallow water) for continued evaluations of existing and new technologies. It was recognized that no absolute standard exists for the determination of the “First-5” across all spatial domains. Therefore, it was agreed that the Directional Waverider DWR-MkIII system was the best available reference/standard for the deep and intermediate water wave evaluations as verified by the laser array (LASAR) at the ConocoPhillips Ekofisk offshore platform complex in the North Sea. The long linear array at the U.S. Army Corps of Engineers’ Field Research Facility could be used as the standard for shallow water wave evaluations. Finally, given the significance of wave measurements, an appropriate level of quality assurance and quality control procedures must be included as part of any test and evaluation effort. The details of the proposed protocols for the verification of wave measurement systems are described.

Two types of analyses are used to investigate the synoptic wind-driven flushing of Tampa Bay in response to the El Nino-Southern Oscillation (ENSO) cycle from 1950 to 2007. Hourly sea level elevations from the St. Petersburg tide gauge, and wind speed and direction from three different sites around Tampa Bay are used for the study. The zonal (u) and meridional (v) wind components are rotated clockwise by 40° to obtain axial and co-axial components according to the layout of the bay. First, we use the subtidal observed water level as a proxy for mean tidal height to estimate the rate of volumetric bay outflow. Second, we use wavelet analysis to bandpass sea level and wind data in the time–frequency domain to isolate the synoptic sea level and surface wind variance. For both analyses the long-term monthly climatology is removed and we focus on the volumetric and wavelet variance anomalies. The overall correlation between the Oceanic Nino Index and volumetric analysis is small due to the seasonal dependence of the ENSO response. The mean monthly climatology between the synoptic wavelet variance of elevation and axial winds are in close agreement. During the winter, El Nino (La Nina) increases (decreases) the synoptic variability, but decreases (increases) it during the summer. The difference in winter El Nino/La Nina wavelet variances is about 20 % of the climatological value, meaning that ENSO can swing the synoptic flushing of the bay by 0.22 bay volumes per month. These changes in circulation associated with synoptic variability have the potential to impact mixing and transport within the bay.

Barrier islands characterize up to an eighth of the global coastlines. They buffer the mainland coastal areas from storm surge and wave energy from the open ocean. Changes in their shape or disappearance due to erosion may lead to an increased impact of sea level extremes on the mainland. A barrier island threatened by erosion is Egmont Key which is located in the mouth of the Tampa Bay estuary at the west-central coast of Florida. In this sensitivity study we investigate the impact a loss of Egmont Key would have on storm surge water levels and wind waves along the coastline of Tampa Bay. We first simulate still water levels in a control run over the years 1948-2010 using present-day bathymetry and then in a scenario run covering the same period with identical boundary conditions but with Egmont Key removed from the bathymetry. Return water levels are assessed for the control and the scenario runs using the Peak-over-threshold method along the entire Tampa Bay coastline. Egmont Key is found to have a significant influence on the return water levels in the Bay, especially in the northern, furthest inland parts where water levels associated with the 100-year return period increase between 5 cm and 15 cm. Additionally, wind wave simulations considering all 99.5th percentile threshold exceedances in the years 1980-2013 were conducted with the same control and scenario bathymetries. Assessing changes in return levels of significant wave heights due to the loss of Egmont Key revealed an increase of significant wave heights around today's location of the island.

The typically observed gravitational circulation in estuaries with lateral variations in bathymetry consists of a combined distribution of vertically and horizontally sheared flows. The distribution features inflow at depth and outflow at the surface and along the sides. However, theoretical results of density-driven exchange flows dominated by frictional effects display a laterally sheared distribution with inflow occupying the deepest portion of the cross-section and outflow over the shoals. The main purpose of this investigation was to obtain observational evidence in support of theoretical results. A tidal cycle survey was conducted on February 24, 2009, to collect current velocity and hydrographic profile data along a cross-estuary transect. Observations from Hillsborough Bay were compared qualitatively to numerical model and analytical solution results. The observed residual exchange flow pattern compared favorably with the results from a numerical model and an analytical solution that used a condition controlled by friction. The relative importance of friction was explored at tidal and subtidal timescales. Intratidally, frictional influences were observed in the spatial distribution of tidal current amplitude and phase, as well as in potential energy anomaly (stratification) variations. Subtidally, frictional influences were observed through the spatial distributions of tidally averaged stratification, turbulent kinetic energy dissipation and eddy viscosity values. The main finding of this study was that relatively weak tidal currents (

We examined short-term phytoplankton and sediment dynamics in Tampa Bay with data collected between 8 December 2004 and 17 January 2005 from optical, oceanographic, and meteorological sensors mounted on a coastal oceanographic tower and from satellite remote sensing. Baseline phytoplankton (chlorophyll- a , Chl) and sediment concentrations (particle backscattering coefficient at 532 nm, bbp(532)) were of the order of 3.7 mg m −3 and 0.07 m −1 , respectively, during the study period. Both showed large fluctuations dominated by semidiurnal and diurnal frequencies associated with tidal forcing. Three strong wind events (hourly averaged wind speed >8.0 m s −1 ) generated critical bottom shear stress of >0.2 Pa and suspended bottom sediments that were clearly observed in concurrent MODIS satellite imagery. In addition, strong tidal current or swells could also suspend sediments in the lower Bay. Sediments remained suspended in the water column for 2–3 days after the wind events. Moderate Chl increases were observed after sediment resuspension with a lag time of ˜1–2 days, probably due to release of bottom nutrients and optimal light conditions associated with sediment resuspension and settling. Two large increases in Chl with one Chl > 12.0 mg m −3 over ˜2 days, were observed at neap tides. For the study site and period, because of the high temporal variability in phytoplankton and sediment concentrations, a monthly snapshot can be different by −50% to 200% from the monthly “mean” chlorophyll and sediment conditions. The combination of high-frequency observations from automated sensors and synoptic satellite imagery, when available, is an excellent complement to limited field surveys to study and monitor water quality parameters in estuarine environments.

Lagrangian retention and flushing are examined by advecting neutrally buoyant point particles within a circulation field generated by a numerical ocean model of Tampa Bay. Large temporal variations in Lagrangian residence time are found under realistic changes in boundary conditions. Two 90-day time periods are examined. The first (P1) is characterized by low freshwater inflow and weak baroclinic circulation. The second (P2) has high freshwater inflow and strong baroclinic circulation. At the beginning of both time periods, 686,400 particles are released uniformly throughout the bay. Issues relating to particle distribution and flushing are examined at three different spatial scales: (1) at the scale of the entire bay, (2) the four major regions within the bay, and (3) at the scale of individual model grid cells. Two simple theoretical models for the particle number over time, N(t), are fit to the particle counts from the ocean model. The theoretical models are shown to represent N(t) reasonably well when considering the entire bay, allowing for straightforward calculation of baywide residence times: 156 days for P1 and 36 days for P2. However, the accuracy of these simple models decreases with decreasing spatial scale. This is likely due to the fact that particles may exit, reenter, or redistribute from one region to another in any sequence. The smaller the domain under consideration, the more this exchange process dominates. Therefore, definitions of residence time need to be modified for “non-local” situations. After choosing a reasonable definition, and removal of the tidal and synoptic signals, the residence times at each grid cell in P1 is found to vary spatially from a few days to 90 days, the limit of the calculation, with an average residence time of 53 days. For P2, the overall spatial pattern is more homogeneous, and the residence times have an average value of 26 days.

Two algorithms designed to detect deepwater oceanic features and arbitrary edge profiles were tuned to automatically delineate fronts in coastal waters off west–central Florida using satellite-derived sea surface temperature (SST), chlorophyll-a concentration (Chl), normalized water-leaving radiance (nLw), and fluorescence line height (FLH) images during select periods in the spring and fall of 2004 and 2005. The dates correspond to recreational king mackerel, Scomberomorus cavalla, tournaments. A histogram-based algorithm was useful to detect coastal surface SST, nLw, and FLH fronts, specifically. A gradient-based algorithm, with a smaller kernel box of 3 × 3 pixels, best identified nearshore (

This paper draws from recent workshops held by the Alliance for Coastal Technologies to summarize the present status of sensors and sensor platforms for making physical oceanographic observations. Technologies reviewed include those for current measurements, HF Radar, wave sensors, drifting buoys, profiling floats, surface meteorological observations, and automated vessel-based systems, as well as related issues of data telemetry and biofouling.

The residual (time-average) salinity and circulation in a numerical ocean model of the Tampa Bay estuary are shown to experience significant temporal variation under realistic forcing conditions. A version of the Estuarine Coastal Ocean Model developed for Tampa Bay with 70 by 100 horizontal grid points and 11 sigma levels is examined for the years 2001–2003. Model output variables are averaged over the entire time of the simulation to generate long-term residual fields. The residual axial current is found to be dominated by the buoyancy-driven baroclinic circulation with an outflow (southwestward) at the surface and to the sides of the shipping channel, and an inflow (northeastward) usually occurring subsurface within or above the shipping channel. Averages over 30 d are used to examine variations in the residual fields. During the simulation the average surface salinity near the head of Tampa Bay varies with the freshwater inflow, from 12‰ to 33%. At the bay mouth salinity varies from 30%. to 36%.. A localized measure of the baroclinic circulation in the shipping channel indicates the residual circulation can vary strongly, attaining a magnitude triple the long-term mean value. The baroclinic circulation can be disrupted, going to near zero or even reversing, when the buoyancy-driven flow is weak and the surface winds are to the northeast. Three time periods, representing different environmental conditions, are chosen to examine these results in detail. A scaling argument indicates the relative strength of buoyancy versus wind as ΔρgH2(LC Dω2)−1, where δρ is head-to-mouth density difference across the bay,g is gravitational acceleration,H is depth,L is bay length,C D is the surface wind drag coefficient, andw is wind speed. Tampa Bay is usually in the buoyancy dominated regime. The importance of winds in the weak-buoyancy case is demonstrated in an additional simulation without wind stress.

Because estuaries and coastal regions are particularly susceptible to nutrient over-enrichment due to their close proximity to source-rich regions, a goal of the BRACE study was to improve estimates of nitrogen air/sea transfer rates in the Tampa Bay Estuary. Our objective was to critically evaluate two air/sea gas exchange models to determine their efficacy for use in a coastal region, with the ultimate goal of improving nitrogen exchange estimates in Tampa Bay. We used meteorological data and oceanographic parameters collected hourly at an instrumented tower located in Middle Tampa Bay, Florida. The data was used to determine the friction velocity and the turbulent flux of heat and moisture across the air/sea interface and then compared with modeled parameters at the same offshore site. On average both models underpredicted sensible heat flux and there was considerable scatter in the data during stable conditions, indicating that nitrogen gas exchange rates may also be underestimated. Model improvement, however, was observed with friction velocity comparisons. Model inter-comparisons of sensible heat flux and friction velocity suggest excellent agreement between the TOGA COARE and the NOAA Buoy models, but model estimated heat transfer coefficients and latent heat fluxes did not agree as well. Based on our analysis, we conclude that both models are suitable for use in a coastal environment to estimate nitrogen air/sea gas exchange, although the NOAA Buoy model requires fewer meteorological inputs. However, if the purpose is to conduct more sophisticated microscale modeling of air/sea interactions, we recommend the TOGA COARE model.

The NOAA Buoy model is currently used to estimate the air–sea transfer rates of highly soluble gases over coastal water bodies, such as Tampa Bay, using offshore meteorological measurements. Since a goal of the BRACE study was to improve estimates of nitrogen deposition over Tampa Bay, our objective was to investigate if the model accurately predicts gas transfer when shoreline input data are used in lieu of offshore measurements. To accomplish this objective, we compared over-water measurements of sensible heat with NOAA Buoy model predictions using both offshore and shoreline meteorology. In the summer months, the apparent daytime influence of land surface heating on air temperature produces a higher air than water temperature at the shoreline. For the NOAA Buoy model, this yields stable atmospheric conditions and thus under-predicts the over-water exchange rates for a shallow estuary. If the data records are removed from the model for periods when air temperature is 4.8 K greater than the water temperature, the shoreline and over-water transfer rates are in reasonable agreement.

Hurricane Frances is shown to greatly alter the hydrodynamics within Tampa Bay, Florida, and the exchange of water with the Gulf of Mexico in both observational data and a realistic numerical circulation model of the Tampa Bay estuary. Hurricane Frances hit Tampa Bay on September 5, 2004 with surface winds peaking twice near 22 m s−1. There were three stages to the hydrodynamic effect of Frances on Tampa Bay. The first stage included the approach of Frances up to the first wind peak. The winds were to the south and southeast. During this stage sea level was maintained below mean sea level (MSL) and the residual current (demeaned, detided) was weak. The second stage began as the winds turned to the east and northeast, as the eye passed near the bay, and ended as the second wind peak appeared. During this stage the residual currents were strongly positive (into the bay), raising sea level to 1.2 m above MSL at St. Petersburg. The measured residual circulation peaked at over +0.7 m s−1 near the surface. The model shows this velocity peak yielded a maximum volume flux into the bay of +44,227 m3 s−1, displacing a total volume of 1.5 billion m3 in just a few hours, about 42% of the bay volume. In the third stage a strong negative flow developed as the wind and sea level relaxed to near normal levels. The ADCP measured a peak outflow of −0.8 m s−1 during this time. Model results indicate a maximum flux of −37,575 m3 s−1, and that it took about 50 h to drain the extra volume driven into the bay by Hurricane Frances.

Consideration of the dependence of various components of the sea-surface heat and momentum fluxes on sea surface temperature (SST) leads to an explanation for the observed reduction in the horizontal temperature gradients in the uppermost layer of the ocean (a few to 10 m in depth). Horizontal temperature gradients within the mixed layer can be masked by a near-surface layer of warm water. This camouflage of horizontal temperature gradients has importance for the remote sensing of SST used by the fishing industry, for the estimation of acoustic transmission, and for the forecasting of hurricane development, among many uses of SST data. Diurnal warming conditions in the Straits of Florida are examined by a simulation calculation and by analysis of observations obtained on moorings deployed on the south-east Florida shelf. When there is net heating (i.e., the solar input is stronger than the combined latent, sensible and longwave radiative heat losses) the originally warmer water experiences less heating than the colder water, leading to a weakening of the horizontal SST gradients as seen by surface buoys or satellites. The warmer water also experiences more mixing and therefore less increase in temperature. The strongest effect of the diurnal heating on wind stress occurs when the SST starts out cooler than the air temperature and the atmosphere is stably stratified. Diurnal warming can then rapidly increase the SST above the air temperature because of reduced wind stress and reduced upper-ocean mixing. After that the wind stress increases as convectively driven turbulence contributes to the atmospheric exchange.

Sampling of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) at the Gandy Bridge monitoring site between May and August 2002 provided preliminary ambient air concentrations and dry deposition rates for Tampa Bay. The HiC-IOGAPS dramatically improved the recovery of lower molecular weight gas and particle PAHs, as evidenced by the recoveries of PAHs in back-up denuders and filter packs. Total PAH (gas+particle) concentrations ranged from 80 to 190 ng m −3 . Concentrations of naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene, and pyrene were consistently higher than concentrations of the remaining 10 PAHs. Assuming an unidirectional flux of these compounds from air to water, the estimated total (gas+particle) dry deposition flux was 11.5 μg m −2 d −1 , or 6.7 μg m −2 d −1 if naphthalene is excluded.

Natural variability in the myriad of physical processes that impact and control estuaries occurs at time scales that typically may exceed or partly exceed many monitoring programs. With respect to documenting and monitoring impacts of human influences- on estuaries, it is therefore important to frame the results of short-term monitoring programs within the context of longer term natural variability in the environment. In the Tampa Bay, Florida area, climate variability strongly influences seasonal precipitation, stream flow, and salinity. In particular, El Nino-Southern Oscillation impacts during the winter have the potential to influence both the availability of surface water for water supply withdrawal and the evaluation of the impacts of surface water withdrawals on the ecosystem.

To succeed at developing a nationwide Integrated Ocean Observing System (IOOS), stakeholders in academia, government, and industry must forge and maintain strategic partnerships. The South Florida Ocean Measurement Center (SFOMC) is such a partnership model and mutually beneficial collaboration that is conducting year-in and year-out major at-sea operations, sustaining the operation of a complex array of sub sea sensors, and providing the maintenance and the shore-based infrastructure to support both. The transformation of a longstanding, narrowly focused, and somewhat antiquated (but highly capable) Navy test and evaluation facility is described. Formerly plagued with a decreasing customer base and increasing operational costs, the Center's transformation into this now fully integrated coalition has mitigated these forerunners of extinction while answering both Navy and academic needs. The successful partnership has resulted in modern facilities, a broad customer base, and steadily decreasing costs of operation. Examples are provided that demonstrate the ability of the Navy's South Florida Testing Facility (SFTF) to realize user cost savings and to aid in the convergence of interest and capabilities among a variety of user groups toward the solution of problems of national concern, including naval research, homeland security, and environmental stewardship.

Estuarine salinity distributions reflect a dynamic balance between the processes that control estuarine circulation. At seasonal and longer time scales, freshwater inputs into estuaries represent the primary control on salinity distribution and estuarine circulation. El Nino-Southern Oscillation (ENSO) conditions influence seasonal rainfall and stream discharge patterns in the Tampa Bay, Florida region. The resulting variability in freshwater input to Tampa Bay influences its seasonal salinity distribution. During El Nino events, ENSO sea surface temperature anomalies (SSTAs) are significantly and inversely correlated with salinity in the bay during winter and spring. These patterns reflect the elevated rainfall over the drainage basin and the resulting elevated stream discharge and runoff, which depress salinity levels. Spatially, the correlations are strongest at the head of the bay, especially in bay sections with long residence times. During La Nina conditions, significant inverse correlations between ENSO SSTAs and salinity occur during spring. Dry conditions and depressed stream discharge characterize La Nina winters and springs, and the higher salinity levels during La Nina springs reflect the lower freshwater input levels.

An ocean surface current radar (OSCR) in the very high frequency (VHF) mode was deployed in South Florida Ocean Measurement Center (SFOMC) during the summer of 1999. During this period, a 29-d continuous time series of vector surface currents was acquired starting on 9 July 1999 and ending 7 August 1999. Over a 20-min sample interval, the VHF radar mapped coastal ocean currents over a 7.5 km /spl times/ 8 km domain with a horizontal resolution of 250 m at 700 grid points. A total of 2078 snapshots of the two-dimensional current vectors were acquired during this time series and of these samples, only 69 samples (3.3%) were missing from the time series. During this period, complex surface circulation patterns were observed that included coherent, submesoscale vortices with diameters of 2 to 3 km inshore of the Florida Current. Comparisons to subsurface measurements from moored and ship-board acoustic Doppler current profiles revealed regression slopes of close to unity with biases ranging from 4 to 8 cm s/sup -1/ between surface and subsurface measurements at 3 to 4 m beneath the surface. Correlation coefficients were 0.8 or above with phases of - 10 to - 20/spl deg/ suggestive of an anticyclonic veering of current with depth relative to the surface current. The radar-derived surface current field provided spatial context for an observational network using mooring-, ship- and autonomous underwater vehicle-sensor packages that were deployed at the SFOMC.

We summarize previous estimates of volume transport and property distributions through the Mozambique Channel and offer additional estimates and measurements based on recently acquired hydrographic and float data. Previously published property distributions are consistent with southward spreading through the Channel. Waters of the Mozambique Channel are characterized by shallow and intermediate oxygen minima separated by a relative maximum. Based on hydrographic sections, the intermediate maximum in dissolved oxygen is seen to decrease in value as it spreads southward. The highest values are found in the westward flow of the South Equatorial Current just north of Madagascar and within the western 200 km of the Channel. Similarly, oxygen concentrations at the intermediate oxygen minimum, which derives from the Arabian Sea, increase southwards, while its depth increases from 900 to 1100 m, supporting previous studies and indicating southward spreading and mixing along the Mozambique Channel. Historical transports based on hydrographic data in the Channel vary from 5 Sv northward to 26 Sv southward depending on reference level and time of the year. Balancing transport below 2500 m (the sill depth in the Channel), we estimate the net southward transports above this depth to be 29.1 and 5.9 Sv for the northern and southern sections, respectively—the difference is presumably related to seasonality and eddy variability superimposed on the mean flow. Individual deep float trajectories show the presence of many eddies, but the overall flow in the channel is southward, and broadly consistent with hydrography. Model outputs also show mean southward transport with considerable seasonal variability. Satellite data show high variability in sea surface height anomalies and high eddy kinetic energy associated with eddy activity. Although the geostrophic transport values are consistent with the historical limits, the lowered ADCP measurements suggest a substantial barotropic component to the flow. Direct long-term measurements of the current are needed to quantify its magnitude and variability.

Hemispherical and regional analyses of climatic patterns relating to El Nino–Southern Oscillation (ENSO) indicate strong responses in the southeastern United States, especially during the wintertime. Using Florida as an example, the authors focused on local-scale patterns within this region in order to examine the geographic variability of seasonal rainfall and river discharge as related to ENSO. Forty-eight years (1950–98) of precipitation and river discharge data in Florida were classified, using sea surface temperature anomaly data from the equatorial Pacific Ocean, as occurring during an El Nino (warm event), La Nina (cold event), or neither (neutral). Seasonal precipitation and streamflow both exhibited strong responses to ENSO as shown by their relationships to Nino-3.4 sea surface temperature anomalies. Florida does not respond as a uniform region to ENSO, particularly with respect to precipitation in the Panhandle and the southernmost areas of Florida. In particular, seasonal river discha...

Spatial and temporal variability in sea-surface temperature (SST) is analyzed by the method of principal component analysis (PCA). Variability of satellite-derived SST from the NOAA/NASA Advanced Very High Resolution Radiometer (AVHRR) Pathfinder data over the Arabian Sea is compared to the PCA of the mixed-layer temperature fields from two different Indian Ocean models. Climatological model output is compared to Pathfinder's “averaged” year using data from 1987 to 1990. A 5-year analysis with data and model output (from 1985 to 1989) is also done. The first mode in all the studies accounts for 58.2–95.8% of the SST variability, and is identified with the seasonal warming and cooling associated with the Indian Monsoon. The second mode accounts for 20.6–31.1% and corresponds to the radiative heating of the basin. Time series of the basin's mean SST shows that the models lag Pathfinder SST by approximately one month. The climatological models fail to reproduce the SST variability, in both space and time, of the Arabian Sea. The Luther–Ji model, forced by interannual monthly winds, does much better. The main discrepancies are likely due to the models’ forcing fields underestimating the strength of the monsoon, and the vertical thermal structure not being adequate to represent the real ocean, especially in upwelling areas.

The relationship between physical forcing and biological response observed in the Arabian Sea for the years 1978–1986 were examined. Spatial and temporal patterns of variability in a climatological time-series of three possible physical forcing parameters and CZCS-derived phytoplankton pigment concentration during the annual cycle were quantified using single and joint empirical orthogonal function (EOF) and singular-value decomposition (SVD) analyses. Monthly composites of the NASA regional pigment data were interpolated to fill data voids and binned corresponding to the physical flux data. Nearly all the spatial-temporal analyses consistently partitioned a large portion of the variability using only 1 or 2 dominant modes and indicated a lag in the timing of the peak pigment concentration behind the maxima in physical forcing. In all cases, major modes of variability resembled the Southwest Monsoon pattern, with the Northeast Monsoon contributing very little to the total variance and covariance. The Joint EOF and SVD analyses incorporated subtle features surrounding the peak Southwest Monsoon phenomena. Correlation maps of the joint EOF analysis depicted differences in spatial variability of pigment concentration associated with stress and curl, showing areas of curl-driven upwelling distinct from coastal upwelling, with possible off-shore advection of the curl-induced high pigment waters.

Trajectory experiments in a thermocline layer of an Indian Ocean model are used to investigate the role of different meridional transport mechanisms and quantify spreading pathways and rates under different forcing. Particles are introduced along two boundaries: the south Indian Ocean at 308S and the Indonesian Throughflow. Particles are advected horizontally within the layer by archived model velocity fields (˜ 83 ˜8 resolution) for a period of 50 years. The velocity fields are the result of forcing the model by monthly mean climatology (case A). The distribution of particles within the Tropics suggests efficient water mass blending; model results show a mixture of three parts South Indian Central Water to one part Indonesian Throughflow. In agreement with chlorofluorocarbon (CFC) observations, transport of thermocline waters along the western boundary into the northern Indian Ocean occurs on timescales of less than two decades. Additional Lagrangian experiments carried out with the seasonality removed from the velocity fields directly (taking the mean in case B) and from the forcing (case C) allow the role of horizontal eddy transport to be evaluated. Significant northward transport of southern subtropical gyre waters along the western boundary does not occur unless there is eddy transport, even though the mean flow appears to dominate the cross-equatorial transport in the immediate vicinity of the equator. Particles reach northward of 108N on shorter timescales (,20 yr) in case A compared with case C (.20 yr). Both the mean and seasonal forcing components are important for the meridional flux of particles. The results suggest that to adequately simulate meridional transport of mass and water mass properties in the Indian Ocean, models should include the full annual cycle. In a new methodology, CFC-11 concentrations along trajectories are calculated using observed CFC-11 concentrations for boundary conditions. Additional CFC observations allow model‐data comparisons to be made in the interior of the domain. The method may be useful in other studies of transport rates and processes where both computing power and good quality high-resolution observations are available.

Mixed-layer CFC-11 saturations measured in the northwestern Indian Ocean during the 1995 World Ocean Circulation Experiment (WOCE) along I7N are compared to those from a numerical model using three alternative parametrizations for the air-sea flux of CFC-11. The Wanninkhof [1992] gas flux parametrization for climatological winds gives gas saturations which agree best with those observed. The observed and model mixed-layers are in equilibrium with the contemporary atmosphere to within 1% (the experimental error) in the summer of 1995, excluding cold coastal upwelled waters. When the model is used to extend the space and time scales of the observations in the Arabian Sea, widespread supersaturations of 5% due to weak winds and warming are predicted in the spring and fall, and under saturations of 5% due to mixing in the winter. The model validation of CFC-11 transfer parametrization and investigation of temporal and spatial variability in saturation are applicable to the physically-forced saturation variations of carbon dioxide and other gases of interest.

The transport of particulate and dissolved matter on the surface of coastal marshes is controlled by the hydrodynamic characteristics of over-marsh flows. High-frequency (5 Hz) in situ measurements of flow speed were collected in Spartina alternijlora, Juncus roemerianus, and Di:-tichlis spicata canopies using hot-film anemometry sensor arrays. These data indicate that mean flow speed, turbulence intensity, and the shape of the vertical speed profile are influenced by variations in plant morphology and stem density. Mean flow speed and turbulence intensity are inversely related to stem density and to distance from the creek edge. Flow energies decrease by about one order of magnitude when flows encounter the vegetated marsh surface and continue to decrease as vegetation density increa,ses. Turbulent flow energy also decays exponentially with increasing distance from the creek edge. Reductions in flow speed coupled with energy decay provide a hydrologic mechanism for sediment deposition patterns commonly observed in marsh systems. Suspended matter transport is also affected by plant-flow interactions. Vertical flow structure is strongly influenced by canopy morphology (plant type and plant shape). Plant-flow interactions result in vertical speed profiles whose shapes deviate from the logarithmic profile typical in free-stream conditions and in the development of transitional flow regimes (i.e. neither laminar nor fully turbulent).

The extensive open marine marshes on Florida's Gulf of Mexico coast constitute one of the largest continuous coastal marsh systems in the U.S.A. and are characterized by (1) the absence of an apparent modern or relict sediment supply, (2) a thin 1-2 m sediment veneer overlying highly karstified bedrock and (3) both low wave and low tidal energy regimes. More importantly, the Florida open marine marsh system appears to be keeping pace with current rates of sea-level rise in spite of a limited inorganic sediment supply and low tidal energies. Although the magnitudes and directions of suspended solid transport and the processes controlling these transports have been rigorously documented for other U.S.A. marsh systems, they have not been documented in the Florida marsh system. Total suspended solid (TSS) concentrations, current speeds and water levels were monitored in Cedar Creek, Florida, so that the TSS loads could be calculated and the processes exerting control over material exchange could be determined. Both TSS concentration and load are modulated by spring/neap variations and time-velocity asymmetries in the tidal currents. Concentrations at the creek mouth increase by as much as two orders of magnitude during strong wind events due to the presence of waves; however, large net sediment loads appear to be related to the coupled effects of waves and large tidal prisms. Waves initially mobilize sediments in the adjacent embayment but increased tidal prisms, and the associated higher velocities, are requisite for transport of this material further into the creek. Large tidal prisms may be the result of astronomically high tides or meteorologically forced tides. In Cedar Creek, the most important meteorological events affecting sedimentary processes are extra-tropical storms. This is because they occur at much higher frequencies than tropical storms and hurricanes, even though the latter are more potent and potentially could transport greater amounts of material. This study identifies the important processes controlling suspended solid transport in the broad expanses of Juncus roemerianus dominated marsh adjacent to the large arcuate embayments prevalent along the west-central Florida marsh coast as described by Hine and Belknap (1988). The processes exerting control over sediment transport in the Cedar Creek drainage basin are similar to those documented in other marsh systems.

The overarching goal of this project is to build a robust, user-driven, sustained, operational Gulf of Mexico Coastal Ocean Observing System (GCOOS). The specific goals of this project are to maintain the existing GCOOS capabilities and, as funding allows, to augment the existing observations to fill gaps and provide enhanced products and services. GCOOS capabilities include components to integrate data sets from diverse providers; assure consistency, quality, and accuracy of the data; create new products needed by users; and provide in a timely and efficient manner the data, products, and services needed by decision-makers, diverse stakeholders, and the public. Physical, meteorological, biogeochemical, and bathymetrical data are major components of the data system.

Coastal areas such as bays and estuaries host 30%–50% of the global human population and shipping ports that handle 80% of world trade. These areas are increasingly vulnerable to chemical and biological contamination and to storm surge in the short term and to sea level rise in the long term.

A coastal risk assessment system simulates the basic physical mechanisms underlying contaminant transport in Tampa Bay. This risk assessment system, comprised of a three-dimensional numerical circulation model coupled to a Lagrangian particle tracking model, simulates the transport and dispersion of a toxic dinoflagellate bloom. Instantaneous velocity output from the circulation model drives the movement of particles, each representing a fraction of a K. brevis bloom, within the model grid cells. Hindcast simulations of the spatial distribution of the K. brevis bloom are presented and compared with water sample concentrations collected during the peak of the bloom. Probability calculations, herein called transport quotients, allow for rapid analysis of bay-wide K. brevis transport showing locations most likely to be impacted by the contaminant. Maps constructed from the transport quotients provide managers with a bay-wide snapshot of areas in Tampa Bay most at risk during a hazardous bloom event.

The West Florida Shelf Coastal Ocean Monitoring Prediction System (COMPS), maintained by the University of South Florida (USF), College of Marine Science (CMS), is one of the largest sub-regional coastal ocean observing systems in the southeast US and Gulf of Mexico coastal region. COMPS collects and disseminates near real-time marine observations to researchers, educators, students, local, state and federal emergency management agencies, and the public via Internet. Realizing the importance of increasing data accessibility, enhancing data integration, and enabling interoperability between sub-regional, regional and federal coastal ocean observing systems, we have made significant improvements to our COMPS data management system. In this paper, we describe implementation of Integrated Ocean Observing System (IOOS) Data Management and Communications Committee recommended technologies to advance COMPS data system towards interoperability.

A coastal prediction system for Tampa Bay, comprised of a numerical circulation model and Lagrangian particle transport model, rapidly produces hindcast/forecast simulations that alert authorities to high impact areas following the introduction of hazardous material into the bay. The effectiveness of the prediction system as an event response tool is evaluated during an anhydrous ammonia spill. A week-long simulation predicts the trajectory of the material due to winds and currents. Physical transport of the model particles alternates from being tidally driven to being driven both by wind action and residual circulation. A forecast simulation showing particle distribution drove field sampling that resulted in the detection of a Pseudo-nitzschia bloom likely initiated from excess ammonium in the bay. An online component of the coastal prediction system is in development to better manage response and mitigation efforts for future hazardous material spills in Tampa Bay.