Research

Ship time dedicated to facilitate experiential learning for UGA and USG graduate and undergraduate students.

Researchers from NOAA's Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami, FL, conduct regular bimonthly hydrographic surveys at 27N in the Florida Straits to monitor the transport and water-mass properties of the Florida Current. The Florida Current is part of the Gulf Stream system, which is the upper limb of the western boundary current system in the North Atlantic Ocean. These cruises are a part of the laboratory’s long-running Western Boundary Time Series (WBTS) project and directly measure the Florida Current at nine locations across the Straits of Florida at 27N, between Jupiter, Florida, and the Little Bahama Bank in the Bahamas. WBTS 27N hydrographic sections, conducted bimonthly throughout the year, are critical to improving our understanding of the North Atlantic Subtropical Gyre circulation and the Atlantic Meridional Overturning Circulation (AMOC). Importantly, data collected during these cruises and others are also used to calibrate the 27N submarine cable system which publicly provides daily transport estimates of the Florida Current . The AMOC is a significant factor in climate change, oceanic carbon sequestration, and sustainable fisheries.

These cruises utilize funding provided by the University of Minnesota. Chief Scientists will be completing seed research cruises or using their ship time to take graduate and undergraduate students on the research vessel Blue Heron.

Characterizing Arctic ocean-ice-atmosphere variability and predicting the system’s evolution on synoptic to seasonal timescales requires observations that span a broad range of spatial and temporal scales. Forecast quality depends on observations for initialization, assimilation, and for informing how the simulations represent unresolved physics. Data intended for use in nowcast/forecast efforts must be delivered in a timely fashion - a challenging requirement for polar regions where ice blocks access to satellite services. To support Navy missions in the ice-covered Arctic, this effort builds on technologies developed during the Arctic Mobile Observing Innovative Naval Prototype (AMOS INP) to maintain a multi-year, persistent presence in the central Arctic to investigate the pathways through which incoming Pacific waters make their way into the central Arctic, and broader questions of the mechanisms responsible for the transfer of heat and momentum in upper ocean. Efforts will also focus on extending the technologies and approaches that allow long-term, persistent autonomous observing, including infrastructure that supports geolocation, platform networking and data exfiltration.

The cruise is dedicated to the retrieval of our Multi-Function Node stuck on the seafloor off Savannah.

Jessica Fitzsimmons, James Moffett, and Nicholas Hawco propose to collect four large volume (1000 L) seawater samples to develop an archive of consensus materials for trace metal analysis. Samples will be collected from the surface and 1000m at the Station ALOHA, and from two stations in the Gulf of Mexico influenced by the Mississippi River outflow. Samples will be collected and filtered using trace metal clean techniques into large-volume tanks, homogenized, and then dispensed into 500mL bottles for archiving and distribution to the community. Samples will be analyzed by groups worldwide for a suite of dissolved trace metals. Their data will be analyzed in collaboration with Antonio Possolo, of the National Institute of Standards and Technology (NIST). Consensus values derived from this synthesis for each element will be reported on the US GEOTRACES Web Site and in a peer-reviewed publication. The majority of samples will be archived for distribution, replacing the exhausted archives of previous intercomparison projects. The last two decades have seen great advances in our knowledge about the distribution and biogeochemical cycles of trace elements in the ocean. This was possible because laboratories worldwide had confidence that their analyses were producing consistent results. The establishment and distribution of consensus standards, from the SAFe (2004) and GEOTRACES (2008-2009) programs, were critical in this development. We propose to collect samples from Station ALOHA, where water chemistry will be very similar to the valuable samples collected in those former consensus-building programs. Those earlier efforts also revealed that there were some intercalibration issues that need to be addressed. For example, copper displays surprising variability in reported values that did not appear to arise from contamination, but could reflect artifacts arising from Cu complexation by organic matter for specific protocols. Cobalt shows similar issues, while vanishingly low surface oligotrophic concentrations of cadmium, zinc, and iron can prevent strong consensus against significant blanks at the picomolar level. These issues and others will be explored by Fitzsimmons, Moffett, Hawco, and other participants in the course of consensus building. Recent field campaigns in margins and estuaries have underscored the importance of a consensus standard in waters containing high concentrations of dissolved organic matter, which may create analytical artifacts for copper and other metals. It also needs to be determined what the constraints on long term storage are for such samples. This is the rationale for collecting a high-organics, lower salinity sample in the Gulf of Mexico.

Seabed surveys with REMUS 3000 AUV offshore San Diego. Seabed characterization with sidescan sonar and optical imagery.

Systematic long-term (greater than a few decades in length) time-series observations of aquatic and terrestrial environments have led to a more comprehensive understanding of the natural ecosystem variability and have enabled an assessment of human impacts on ecosystem dynamics. Because of their ability to store and transport large amounts of heat and to absorb carbon dioxide from the atmosphere, the world's oceans play a critical role in modulating environmental conditions for the sustained well-being of both land-based and marine organisms including humans. Despite their recognized scientific and societal importance, long-term records of key ocean processes are rare. In 1988, the Hawaii Ocean Time-series (HOT) program, near Hawaii was established. For over three decades, teams of scientists based at the University of Hawaii have made critical measurements of the 'state of our sea.' These long-term observations have established a baseline against which future states can be compared. The ship-based HOT program complements other diverse ocean observation programs including remote-sensing via satellites, moored buoys, profiling floats, and autonomous underwater vehicles. All HOT program data are publicly available and are frequently used by researchers and policy makers around the world.

Understanding the acoustic variability and spatio-temporal dynamics of ocean processes impacting signal detection and ocean sound propagation at scales larger than a specific locale and longer than 1-2 years necessitates sustained observations and measurements. This program will service 5 acoustic bottom landers and conduct seafloor characterization at the 5 lander positions with an additional sixth site at the terminus of a cabled ocean observation platform. The program aims to assess patterns and trends in acoustic, oceanographic and air-sea interface dynamics through long time series analyses that will lead to transformative research related to 1) source detection/classification/ localization methods, 2) predicting habitat suitability of marine mammals through the development of Species Distribution Models, 3) understanding soundscape dynamics related to source energy densities, 4) characterizing seafloor scattering/ reflection and it relationship to bottom substrate and composition, and 5) investigating the variability of bio-physical interactions by developing echosounder-based indices for multiple types of lower trophic level organisms.

Oceans, estuaries and coastal habitats are changing quickly, driven by both natural processes and human activities. The Washington Ocean Acidification Center (WOAC) was established by the state legislature to advance research and monitoring of ocean acidification and its biological effects in Washington waters. One facet of that research is the WOAC cruises. We go out three times a year, April, July, and September, to monitor ocean acidification and its affect on biology. These cruises are part of a long term time Ocean Acidification time series.

This project seeks to test several hypotheses regarding the origins of mantle-derived magmas and their volatiles beneath the Auckland Volcanic Field and other, related volcanic centers behind the arc in northwestern New Zealand. The main goals will be imaging seismic signatures of temperature, melting, and volatiles to understand better how intraplate volcanics form away from deep-mantle plumes. The target extends from the crust to base of the transition zone, so a 700-1000-km array aperture is needed, with full broadband capability. There are three major collaborator groups. A group from University of Auckland will lead collection of the onshore broadband array, densifying permanent networks. A research group at SUSTech, Shenzhen, China will deploy a 20-instrument intermediate-period OBS deployment starting late 2022, offshore northwest New Zealand, focusing on a dense region between Auckland and the southern Kermadec arc . The US OBS proposal here is for a regional fully broadband array, providing the primary tool for regional surface-wave imaging and transition-zone imaging. The US broadband OBSs are in a sparse array around the whole region. The aggregate array will have about 40-50 km station spacing on land, with sparser offshore spacing. We expect overlap with the US OBS deployment and the New Zealand on-land deployment, and hope for some overlap with the SusTech OBSs.

We will be conducting sediment coring and hydrocast surveys, and running experiments using radioisotope on the Louisiana Shelf in late summer/fall 2026 and spring 2027.

Placement of a neutrino detector in Western Lake Superior

Ocean/atmosphere coupling influences atmospheric river (AR) track, timing, and intensity. Uncertainty in ocean conditions both far upstream and just prior to landfall – as well as inadequacies in the parameterizations of air-sea exchange in forecast models – can yield significant forecast uncertainty even on short time horizons (1-3 d). Similarly, it is not yet clear the extent to which ocean/atmosphere interactions impact the development of extreme AR events, for example from “stalling” fronts (e.g. Zou et al. 2023), or those that occur during conditions of anomalous ocean heat content (e.g. El Nino; Bartusek et al. 2021). Key to improving our understanding of the coupled ocean/atmosphere evolution during the formation and passage of an atmospheric river is the collection of in situ research-grade air/sea fluxes and ocean boundary layer response in high resolution and in real time. Under past ONR funding, we have collaboratively developed a system that provides this information at the sea-surface and continuously across the ocean boundary layer to depths of several hundred meters, utilizing a unique ocean wave-powered profiler and a relatively low-cost, easy-to-deploy buoy.

NSF Directorate for Geosciences Office of Integrative Activities

We will investigate the role of stratification in governing the quality of organic particles and particulate flux to the seafloor, as a potential control on benthic-pelagic coupling and the supply of food resources for lower trophic-level consumers. We hypothesize that stratification influences nutrient cycling and distribution, contributing to differences in composition of plankton communities among water masses, which in turn affect the biochemical composition of organic particles. Our project will quantify biogeochemical processes in distinct water masses of the NBS, characterizing structure of plankton communities, sinking rates and quality of organic particles they produce, and the fate of these particles at the seafloor as they are processed by the benthic community. A coordinated field effort will involve both vessel- and mooring-based physical, chemical, biological and biogeochemical measurements designed to capture mechanistic links between water-column stratification and the nature and fate of organic material. Ship-based surveys and moored instrumentation will be used to characterize stratification in the NBS during the summer months, and to sample plankton communities and particles in discrete water masses on either side of density interfaces, e.g. the Bering Sea cold pool and the overlying surface water.

SEFIS is a fishery-independent research group that surveys reef fish using traps and video from Cape Hatteras, NC, to St. Lucie Inlet, FL, from 15-115 m deep.

Deployment (and eventual recovery) of multiple full-ocean depth moorings to study the nonlinear transfer of energy in the internal wave field from tidal frequencies and wavelengths to super-tidal frequencies and shorter wavelengths. The goal is to improve numerical forecast models that recently have been able to include ever more realistic internal waves.

FOCUS will investigate the relationship between sea-level changes in coastal Florida and variations in Gulf Stream transport of water and heat through Florida Straits. To address this goal, the project will use in-situ measurements of velocity, pressure and sound signals along a cross-section between Florida and The Bahamas. These measurements will lead to a better understanding of how 'sunny-day' flooding events in South Florida are linked to oceanic conditions offshore. Results will also illuminate links between variations in different components of Gulf Stream transport and the gyre and overturning circulation and heat content at basin scale. Investigators will interact closely with resilience program managers of a county in southeast Florida that is affected by increasingly frequent flooding from the ocean.

Michael Rennie at Lakehead University proposes to revisit the Lake Superior Shoals and recovery and redeploy gear that was left on the shoals.

Methane seeps affect the geology, ecology, and chemistry of the near-seafloor environment. We will investigate newly-discovered methane seeps along the slope of the northern US Atlantic Margin. We will describe and study the characteristics, biogeochemistry, and evolution over the geological time of seeps along two representative transects extending from the shelf edge to the continental rise.