OS23H-01 INVITED
The U. S. Contribution to the Global Ocean Observing System (GOOS)
The Integrated Ocean Observing System (IOOS) is the U.S. contribution to the Global Ocean Observing System (GOOS). Currently, efforts are underway to build the North American GOOS Regional Association, which would include the United States, Canada, and Mexico. The global component of IOOS contributes to GOOS through a number of different systems including the Global Tide Gauge Network, the Global Surface Drifting Buoy Array, the Tropical Moored Buoy Network, and the Argo Profiling Float Array. The National Oceanic and Atmospheric Administration (NOAA) is taking the U.S. federal government lead for IOOS. NOAA has begun the work needed to integrate and make interoperable five core variables for IOOS: temperature, salinity, sea level, surface currents, and ocean color. These five variables were chosen because they are critical for a number of ocean modeling efforts (consistent with NOAA's mission objectives) including hurricane intensity, coastal inundation, harmful algal bloom forecasts, and assessment of complex ecosystems. NOAA will continue to support the development of U.S. IOOS Regional Associations. There are currently 11 regions defined that are contributing to IOOS. The Regional Associations and the Regional Coastal Ocean Observing System (RCOOS) data are important components of a fully implemented U. S. IOOS and already contribute a significant data stream to IOOS activities.
OS23H-02
COOL Observations on the Biogeochemistry of the Mid-Atlantic Bight
The Mid-Atlantic Bight (MAB) has exhibited significant changes in the last decade; however the implications for the
shelf biogeochemistry remain an open question. We are using an integrated ocean observatory to study the
productivity and its associated transport on the Mid-Atlantic Bight (MAB). We have constructed a shelf-wide ocean
observatory, anchored by four enabling technologies, to characterize the physical forcing of continental shelf
primary productivity in the New York Bight (NYB). An international constellation of ocean color satellites, multi-
static high frequency long-range surface current radar, real-time telemetry moorings, and long duration
autonomous underwater vehicles (AUVs) are all controlled through a centralized computer network dedicated to
receiving, processing and visualizing the real-time data and then disseminating results to both field scientists
and ocean forecasters working in the MAB. On an annual basis overall half of the primary productivity of the MAB is
associated with winter and early spring productivity during the onset of shelf stratification. This is complemented
by productivity associated with buoyant river plumes, dominated by the Hudson River, which provides 1/4 of the
productivity largely during late spring and early summer. Close to 2/3s of the buoyant waters from the Hudson
river flow out along the edge of the Hudson shelf valley which then flows south on the MAB along mid-shelf front.
As the Hudson river contributes a significant fraction of the shelf productivity, the jet provides an efficient
mechanism for transporting nearshore carbon and larval species to the shelf break/slope from the near shore
waters. Transport onto the slope is mediated by offshore large warm rings. Transport across the Hudson canyon
appears to be severely limited and is a defining feature for the biogeography of the shelf suggesting unique biotic
provinces north and south of the Hudson canyon. Summer upwelling accounts for the remaining 25% of the
annual shelf productivity; however much of the productivity remains nearshore which fuels local fisheries and
topographically driven hypoxia/anoxia.
http:marine.rutgers.edu/cool
OS23H-03 INVITED
Development, Implementation and Evaluation of a Real-Time Ocean Forecasting System off the California Coast
The development and implementation of a real-time ocean forecast system based on the Regional Ocean Modeling System (ROMS) off the coast of California are described. Results produced by the real-time ocean forecast system during two field experiments during the summers of 2003 and 2006 are presented. The real- time ocean forecasting system is based on a nested ROMS configuration including the U.S. West coastal ocean at 15-km resolution, the central California coastal ocean at 5-km, and the Monterey Bay region at 1.5-km. All nested models have 32 vertical sigma (or terrain-following) layers. Using the 3-dimensional variational data assimilation (3DVAR) scheme, we assimilate both the satellite altimeter data and other complementary data sets (both in situ and remote sensing) every six hours to produce nowcast (or analysis) field, from which a 48-hour forecast can be performed. The nowcast and forecast fields are first compared with the assimilated data for consistency check. An evaluation of the ROMS nowcast and forecast against the independent measurements that are not assimilated into models is then conducted. Predictability analysis will also be presented and discussed. The above described real-time ocean forecast system is currently being implemented for real-time operational demonstrations on the 24/7 basis. The system will provide 3-dimensional ocean nowcast and 48-hour forecast fields every six hours. We will share our early experiences interacting with application users (e.g., coast guard, oil spill response team, coastal resource managers). The potential impact of the next generation altimeter mission at high resolution will also be discussed.
OS23H-04
The Red Edge: Exploring high near-infrared reflectance of phytoplankton and submerged macrophytes and implications for aquatic remote sensing
Terrestrial vegetation and submerged macrophytes (seagrasses and seaweeds) exhibit strong reflectance in the near-infrared (NIR) portion of the electromagnetic spectrum (700-1600 nm). This NIR reflectance is commonly attributed to scattering from cell and leaf structures (cell walls and membranes, organelles, air spaces, etc.), and forms the basis of the terrestrial biomass parameter NDVI (normalized difference vegetation index). NIR reflectance is generally ignored for aquatic systems because water strongly absorbs infrared light. Here, we present laboratory measurements of visible and near infrared reflectance from a variety of phytoplankton cultures and in situ measurements of reflectance from different species of seagrass. Reflectance spectra from a variety of taxa Through reflectance measurements made on unpigmented and pigmented leaves, we hypothesize that photosynthetic pigments produce the red edge signature by absorbing visible, but not NIR, radiation. For dense suspensions of algal cells at the sea surface and submerged macrophytes, the infrared reflectance signal can be strong enough that it is not fully attenuated by the water, producing peaks in the reflectance spectra that are red-shifted relative to those produced by chlorophyll fluorescence. High resolution airborne imagery collected in conjunction with the California Center for Integrative Coastal Observations, Research and Education (CICORE) demonstrates elevated NIR reflectance apparent during intense surface algal blooms. The utility of the red edge signature for remote sensing applications in aquatic environments is discussed.
OS23H-05
A West Florida Shelf ROMS Nested into HYCOM: Ensemble-based Assimilation of HF-Radar Surface Currents and a 2005 Red Tide Case Study with Simulated Drifters
A West Florida Shelf (WFS) model is constructed by nesting the Regional Ocean Model System (ROMS) in the
Atlantic Hybrid Coordinate Ocean Model (HYCOM) to include both local and deep-ocean forcing, particularly the
Gulf of Mexico Loop Current (LC). Hindcast experiments from 2004 to 2006 are presented and compared to
observed temperature (moorings and BSOP profiling floats), ADCP velocity time series and HF-Radar surface
currents.
Two different mixing schemes (Mellor Yamada level 2.5 and K-Profile Parameterization, KPP) are tested and the
importance of the vertical resolution for mixing is addressed. The model results of those different configurations
are compared to temperature observations on the shelf. Results obtained with the Mellor Yamada scheme are
closer to observations during winter (negative buoyancy flux and strong winds) while in summer (positive
buoyancy flux and in general weaker wind) the KPP scheme produces more realistic results.
Given the present HYCOM configuration we assessed the benefit of nesting ROMS in HYCOM compared to
nesting ROMS in climatology. The model solutions on the shelf were compared to various in situ data. The model
performed best when using the HYCOM boundary values.
Simulated trajectories for drifters deployed off Tampa Bay and Sarasota were used to address the evolution of
Karenia brevis concentrations during the 2005 red tide. Near surface drifters were advected offshore, whereas
drifters deployed in the bottom Ekman layer matched the subsequently observed Karenia brevis distributions,
showing the importance of the 3D structure of coastal ocean currents for red tide on the WFS.
As a first attempt at assimilating CODAR surface currents we used an ensemble simulation carried out under
different wind forcings to estimate the error covariance of the model state vector and the covariance between the
ocean currents and the wind. Improvements were obtained for the modeled currents, not only at the surface, but
also at depth.
http:ocgmod1.marine.usf.edu/
OS23H-06
Cross-shelf transport of freshwater in the New Jersey shelf
The New Jersey Shelf Observing System, which includes real-time access to the international constellation of ocean satellites, a nested HF CODAR radar network, cabled moorings and a fleet of Webb Sloccum gliders, is used to investigate the freshwater content over the New Jersey shelf. Repeated hydrographic surveys about 100 km south of the Hudson River mouth were conducted using gliders during spring and summer 2006. Observations reveal a strong seasonal cycle in the surface salinity. Buoyant water is restricted to being close to the coast during spring, but spans the entire shelf width during summer. During late July and August, freshwater lenses with large density anomaly are found up to 100 km from the coast. The cross-shelf transport of the freshwater is inconsistent with a model based on Ekman dynamics [Lentz, 2004], suggesting that other processes are responsible for the rapid cross-shelf transport. Surface velocity maps derived from HF radar, satellite imagery and drifter trajectories revealed the existence of a jet directed offshore and to the south, from near the river mouth toward the study region. This provides a direct pathway for transporting freshwater and any biogeochemical material it contains (including phytoplankton, dissolved organic and non-algal particulate matter) across the shelf. The highest frequency of observation of the freshwater lenses offshore occurs when the jet transport is large, and the river discharge is relatively high. The transport in the jet is correlated with upwelling winds on scales of a few days.
OS23H-07
Ocean Observing Science: A New View of the Gulf of Maine
A comprehensive, real-time, ocean observing system that includes an array of moored physical and optical sensors, shore based long-range CODAR for surface current mapping, numerical circulation and wave modeling, and satellite observations began operations in 2001. At the heart of the Gulf of Maine Ocean Observing System is an array twenty two real-time, solar-powered oceanographic data buoys that are rotated at eleven monitoring sites in the Gulf. Buoys are located at sites chosen for the monitoring of major inflows and the principal features of the gulf-scale circulation. Additional buoys are deployed within the major bays and estuaries of the Gulf, where they monitor location conditions and gulf/bay exchanges. The Gulf of Maine is a harsh environment that has presented numerous challenges to the in situ observing system. However, the buoy array has evolved into a very reliable real-time system that has delivered time-series measurements long enough to provide the first indications of seasonal cycles and significant interannual variability that combine to produce previously unrecorded reversals of the canonical Gulf of Maine circulation features and contribute to major hydrographic anomalies that affect large regions of the Gulf last for several years.
OS23H-08
RuCool Operational Oceanography: Using a Fleet of Autonomous Ocean Gliders
At the Rutgers University Coastal Ocean Observation Lab (RU-COOL), we have constructed a shelf-wide ocean
observatory to characterize the physical forcing of continental shelf primary productivity in the New York Bight
(NYB). The system is anchored by four enabling technologies, which include the international constellation of
ocean color satellites, multi-static high frequency long-range surface current radar, real-time telemetry moorings,
and long duration autonomous underwater vehicles (AUVs). Operation of the observatory is through a centralized
computer network dedicated to receiving, processing and visualizing the real-time data and then disseminating
results to both field scientists and ocean forecasters over the World Wide Web. The system was designed to
conduct cutting edge research requiring the addition of rapidly evolving technologies, and to serve society by
providing sustained data delivered in real-time. Rutgers COOL continues to work closely with Webb Research
Corporation (WRC) in testing and development of the Slocum underwater gliders and continues to apply Slocum
gliders in field operations spanning the globe. The continued strong collaboration between WRC and Rutgers
has led to advances in glider operations and applications. These include deployment/recovery techniques,
improvements in durability and reliability, integrated sensors suites, salinity spike removal, and adaptive controls
utilized to optimize mission goals and data return. The gliders have gathered numerous data sets including salt
intrusions as seen off of New Jersey, plume tracking, biological water sample matching, and operation through
Hurricane Ernesto in 2006. This talk will detail recent oceanographic experiments in which the fleet has been
deployed and improvements in the operation of these novel robotic vehicles. These experiments, in locations
around the world, have resulted in significant new work in operation of underwater gliders and have gathered new
and unique data sets. Recent accomplishments include deployment of a glider in Antarctica for LTER, control of
a fleet of gliders during the ONR sponsored Shallow Water 06, RIMPAC, LATTE, ASAP, and the continuation of
long-term observation at the LEO-15 New Jersey site Endurance Line. To date Rutgers has flown close to 100
glider missions, with over 27,000 km flown over 760 calendar days and 1,350 glider days in the water. Operations
around the world are orchestrated remotely from COOL at Rutgers. Computer networking allows for command
and control of the glider fleet from the COOL Lab or remotely via the internet. This system has enabled new
oceanographic experiments at significantly reduced cost, with increased reliability, and with extended continuous
operational deployments in the global oceans since 2003.
http:marine.rutgers.edu/cool