GSO posters Ocean Sciences 2012
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February 20, 2012
A MODELING STUDY OF THE SEASONAL VARIABILITY OF THE CIRCULATION IN THE RHODE ISLAND SOUND AND BLOCK ISLAND SOUND
Recent observations have shown that the Rhode Island Sound (RIS) and Block Island Sound (BIS) exhibit significant and curious seasonal changes in their circulation patterns. Strong cyclonic flow exists during summer, stratified conditions, but disappears during winter, vertically mixed conditions. Several process-oriented, hypotheses-driven experiments with a high-resolution version of the Regional Numerical Modeling System (ROMS) are implemented to understand the mechanisms that determine this behavior. Results show that seasonal fluctuations in wind combine with residual tidal currents to shape the RIS seasonal variability while buoyant discharge from the Connecticut River must be included to understand the seasonal cycle of the BIS.
Liu, Q. ., University of Rhode Island, Narragansett, USA, qianqianliu@gso.uri.edu Luo, Y. ., University of Rhode Island, Narragansett, USA, yluo@gso.uri.edu Rothstein, L. M., University of Rhode Island, Narragansett, USA, lrothstein@gso.uri.edu
Poster presentation
Session #:006 Date: 2/20/2012 Time: 08:00 - 16:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1242
BOUNDARY EFFECTS OF OXYGEN MINIMUM ZONE EXPANSION ON ZOOPLANKTON IN THE EASTERN TROPICAL NORTH PACIFIC
Oxygen minimum zones (OMZs) may be expanding as global climate changes. A spatial comparison between two stations (Tehuantepec Bowl, Costa Rica Dome) with different OMZ thicknesses in the Eastern Tropical North Pacific served as a proxy for temporal change to show how variability in oxycline depth may have broad consequences for distributions and ecosystems. Day and night vertically-stratified zooplankton to 1000m was collected with a MOCNESS during two cruises. Similar biomass features were present at both locations but responded differently to changes in OMZ thickness. Peak biomass occurred at the thermocline. At the Lower Oxycline, a secondary biomass peak occurred. This layer, locked into position by oxygen concentration, changed depth by over 200m between locations. In contrast, another secondary biomass peak at the daytime depth of diel vertical migration occurred at a constant depth at both locations, despite different oxygen levels. The vertical re-positioning of biomass layers, and the increased depth range of low oxygen water that diel vertical migrators and sinking particles must transit in an expanded OMZ, could have widespread effects.
Wishner, K. F., University of Rhode Island, Narragansett, USA, kwishner@gso.uri.edu Outram, D. ., University of Rhode Island, Narragansett, USA, doutram@gso.uri.edu Seibel, B. ., University of Rhode Island, Kingston, USA, seibel@uri.edu Daly, K. ., University of South Florida, St Petersburg, USA, kdaly@marine.usf.edu
Poster presentation
Session #:014 Date: 2/20/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B0947
DYNAMICS IN MARINE ECOSYSTEMS
Specifying effective ecosystem-based management strategies requires an understanding of the status, trends and interactions among key ecosystem components. Fisheries independent surveys sample major portions of marine systems and can be considered a proxy for many of the important ecosystem components. They also provide a means to compare upper trophic levels across large marine ecosystems. We quantified the potential mechanisms which drive changes in biomass among diet based functional groups with a linear, multispecies Gompertz model. Using a trawl survey database representing a number of large marine ecosystems from around the world we were able to parse out changes in biomass due to density-dependence, interactions between functional groups, fishing pressure and climate change. Through our analysis we hope to provide insight into the general ecological organization of marine systems that would enhance ecosystem-based management.
Bell, R. J., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, brell@gso.uri.edu Fogarty, M. J., National Marine Fisheries Service, Northeast Fisheries Science Center, NOAA, Woods Hole, USA, michael.fogarty@noaa.gov Collie, J. S., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, jcollie@gso.uri.edu
Poster presentation
Session #:139 Date: 2/20/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: A0519
CURRENT-METER PERFORMANCE COMPARISON IN HIGH CURRENT CONDITIONS IN DRAKE PASSAGE
Previous current-meter intercomparisons suggest that Aanderaa RCM11s are biased low in the speed range 0-35 cm s-1. A short near-bottom (4000 m depth) mooring deployed in Drake Passage revisits this bias. The mooring consisted of seven current meters representing four models (two VMCMs, two RCM11s, two Aanderaa SEAGUARDSs, and a Nortek Aquadopp). Two high-current events occurred (>35 cm s-1). All current-speed measurements agreed within about 5%. The VMCMs, chosen as the reference, were found to measure the median of the mean-current magnitudes. The RCM11 and SEAGUARD current speeds did not differ significantly from a 1:1 relationship with the VMCMs, and all three types tended to agree best at higher speeds (35-70 cm s-1). The Aquadopp current speeds were about 5% higher than the VMCMs but because of a short record this comparison only extended over the range 0-40 cm s-1.
Kennelly, M. A., University of Rhode Island/Graduate School of Oceanography, Narragansett, USA, m.kennelly@gso.uri.edu Watts, D. R., University of Rhode Island/Graduate School of Oceanography, Narragansett, USA, rwatts@gso.uri.edu Tracey, K. L., University of Rhode Island/Graduate School of Oceanography, Narragansett, USA, ktracey@gso.uri.edu Donohue, K. A., University of Rhode Island/Graduate School of Oceanography, Narragansett, USA, kdonohue@gso.uri.edu
Poster presentation
Session #:004 Date: 2/20/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B2054
WHAT IS HAPPENING AT THE NORTHWEST CORNER OF THE NORTH ATLANTIC CURRENT?
The North Atlantic Current (NAC) travels northward east of the Grand Banks until approximately 50oN where it makes a sharp turn to the east. Previous analysis of sea level variability in this region, known as the Northwest Corner, showed a quasi-regular production of anticyclonic eddies, some of which appear to disappear in place. It was hypothesized that these eddies become denser due to a large latent heat flux to the atmosphere and that they sink in place. To address these ideas, four high resolution and two broader scale hydrographic surveys in two separate expeditions spanning a three-month period during Spring 2011 were undertaken. Results from these surveys as well as output from the data assimilative HYCOM model of this region will be discussed. Evidence of interaction of eddies with the NAC, including the spin up and decay of eddies, and interleaving and subduction between the different water masses in the region will be presented.
Hebert, D. ., Bedford Institute of Oceanography / DFO, Dartmouth, Canada, David.Hebert@dfo-mpo.gc.ca Ullman, D. S., University of Rhode Island / GSO, Narragansett, USA, d.ullman@gso.uri.edu Sutyrin, G. ., University of Rhode Island / GSO, Narragansett, USA, g.sutyrin@gso.uri.edu Rossby, H. T., University of Rhode Island, Narragansett, USA, t.rossby@gso.uri.edu
Poster presentation
Session #:068 Date: 2/20/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1894
EDDY FLUXES AND VORTICITY BALANCE IN DRAKE PASSAGE
As part of the cDrake experiment, an array of current meter-pressure sensor-inverted echo sounders deployed at 45 km spacing in the Polar Frontal zone in Drake Passage has provided three years of daily near-bottom current, bottom pressure, and round trip vertical acoustic travel time between sea floor and sea surface with spatial resolution sufficient to capture mesoscale eddies. Using empirical relationships determined by historical hydrography, objective maps of travel time data can be converted to vertical profiles of baroclinic currents. Daily geostrophic currents and bottom pressure thus enable us to estimate the terms of the geostrophic momentum and vorticity balances, including Reynolds stresses. We find that eddy terms are important in the vorticity balance. Relative vorticity advection is an order of magnitude larger than planetary vorticity advection. The eddy and mean contributions to relative vorticity advection are of the same order.
Firing, Y. L., Scripps Institution of Oceanography, University of California, San Diego, La Jolla, USA, yfiring@ucsd.edu Chereskin, T. K., Scripps Institution of Oceanography, University of California, San Diego, La Jolla, USA, tchereskin@ucsd.edu Watts, D. R., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, rwatts@gso.uri.edu Tracey, K. L., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, ktracey@gso.uri.edu
Poster presentation
Session #:004 Date: 2/20/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B2058
NEAR 13-DAY BAROTROPIC OCEAN RESPONSE TO THE ATMOSPHERIC FORCING IN THE NORTHWESTERN PACIFIC
Ocean bottom pressure measurements from an array of 43 pressure-recording inverted echo sounders, which were part of the Kuroshio Extension System Study (KESS), reveal fluctuations of about 13-day period in the Northwestern Pacific. The fluctuation is characterized by “common mode” which shows coherent in-phase oscillations with a relatively large amplitude in the northeastern part of the observational domain. It also shows energetic fluctuations in the winter season during the 2-year observational period. Regression analysis with wind stress curl field reveals a significant correlation between them, which suggests that the near 13-day barotropic ocean response observed from the bottom pressure array is driven by the large-scale atmospheric forcing in the Northwestern Pacific. This finding is confirmed by a daily-wind forced barotropic ocean model that produces similar near 13-day sea level fluctuations.
Na, H., University of Rhode Island, Narragansett, USA, hanna.ocean@gmail.com Park, J. ., Korea Ocean Research&Development Institute, Ansan, Republic Of Korea, jhpark@kordi.re.kr Lee, H. ., Korea Maritime University, Busan, Republic Of Korea, hjlee@hhu.ac.kr Watts, D. R., University of Rhode Island, Narragansett, USA, rwatts@gso.uri.edu
Poster presentation
Session #:068 Date: 2/20/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1887
EXCHANGE ACROSS AN ESTUARINE-SHELF INTERFACE: IMPLICATIONS FOR LARVAL TRANSPORT
The interaction of estuarine and coastal ocean circulation affects delivery of planktonic larvae into estuaries, which are important nursery habitats for many species. Observations and hydrodynamic model simulations of the Narragansett Bay estuary and the adjacent shelf reveal complex circulation dynamics at the interface between the estuarine and coastal waters. We compare these dynamics with observed vertical distributions of fish larvae near the estuary mouth to investigate processes and pathways of larval transport. During the winter, classic two-layered estuarine flow extends onto the shelf, allowing potentially continuous ingress of larvae. During the summer, a persistent coastal current bypasses the estuary mouth and near-bottom circulation is weak and rotary. Larvae are predicted to enter the estuary via two different pathways: (1) a narrow zone along the coastline upstream of the estuary or (2) during episodic wind-driven events. Variation in seasonal reproductive cycles and swimming behavior will impact rates of delivery of larvae into the estuary. We discuss the physics of exchange at the mouth of Narragansett Bay and implications for fish population connectivity in the region.
Pfeiffer-Herbert, A. S., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, annaph@gso.uri.edu Kincaid, C. R., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, kincaid@gso.uri.edu Bergondo, D. L., U.S. Coast Guard Academy, New London, USA, Deanna.L.Bergondo@uscg.mil Collie, J. S., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, jcollie@gso.uri.edu Ullman, D. S., Graduate School of Oceanography, University of Rhode Island, Narragansett, USA, d.ullman@gso.uri.edu
Poster presentation
Session #:126 Date: 2/20/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1677
February 21, 2012
ON THE STRUCTURE OF CURRENTS IN THE FAROE-SHETLAND CHANNEL AND OVER THE ICELAND-FAROE RIDGE
The long-term exchange of water between the North Atlantic and the Nordic Seas is a central element for understanding the Meridional Overturning Circulation. We use a 75 kHz ADCP on the high-seas ferry Norröna in service across the Faroe-Shetland Channel and along the Iceland-Faroe Ridge to monitor currents down to ~600 m. The database comprises 266 transits across the former and 99 along the latter sections from March 2008 to March 2011. Our average northward flows across the two sections are 4.0 (above 27.8 σt) and 5.3 Sv, respectively, while the corresponding outflows are -3.0 and -2.4 Sv. Assuming an additional 1.9 Sv outflow below 27.8 σt through the Faroe-Shetland Channel (Hansen et al. 2008), the net fluxes become 9.4 and -7.2 Sv thus, the total inflow across the Iceland to Denmark section is 2.2 Sv. Matching these transports against the mean temperature and salinity data along these sections indicates a northward heat flux of 160 TW and a northward salt flux of 0.8 kg s-1x108. Implications for the regional volume, heat and salt balances will be discussed.
http://po.msrc.sunysb.edu/Norrona
Flagg, C. N., Stony Brook University, Stony Brook, USA, cflagg@ms.cc.sunysb.edu Rossby, T. ., University of Rhode Island, Kingston, USA, trossby@gso.uri.edu
Poster presentation
Session #:032 Date: 2/21/2012 Time: 08:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B1785
OBSERVATIONS OF AN INTENSE ANTICYCLONIC EDDY IN THE NORWEGIAN SEA
The deep pool of warm water in the Lofoten Basin of the Norwegian Sea is well-known, and for decades there has been suggestive evidence of a permanent anticyclonic eddy centered over the deepest spot in the basin. A survey of the region in the summer of 2010 revealed for the first time the presence of an intense eddy with a core of adiabatic water from below a shallow seasonal mixed layer to >1000 m. The ADCP data revealed a very well-defined axi-symmetric velocity structure with a core relative vorticity of -0.9 (f = local Coriolis parameter) and highest velocities (0.7-0.8 m/s) at about 18 km radius (at 6-700 m depth). The stability of the eddy was documented by RAFOS floats that remained in the eddy up to 300 days. A float at 900 m depth near the center exhibited an orbital period of 26.0 hours, only 2% longer than the pendulum day, for over 50 days. Whereas a float at the same depth and radius of 17 km, orbited with a period of less than 48 hrs for 100 days.
Søiland, H. ., Institute of Marine Research, Bergen, Norway, henrik@imr.no Rossby, T. ., University of Rhode Island, Narragansett, USA, trossby@gso.uri.edu
Poster presentation
Session #:032 Date: 2/21/2012 Time: 08:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B1784
THE ROLE OF KOSHU SEAMOUNT IN GENERATING THE KUROSHIO LARGE MEANDER SOUTH OF JAPAN FROM DATA-ASSIMILATED HYCOM OUTPUTS
Several mechanisms have been suggested to explain the transition of Kuroshio path from non-large to large meander south of Japan. Recently, a series of studies using satellite altimetry measurements, reanalysis data, and simplified numerical simulations demonstrates an essential role of Koshu Seamount located south of Cape Shiono-misaki, Japan, in generating the Kuroshio large meander. This study confirms the role of Koshu Seamount using data-assimilated HYbrid Coordinate Ocean Model (HYCOM) outputs. Analyses of model outputs reveal the interaction between deep abyssal anticyclonic circulation around Koshu Seamount and the Kuroshio, which amplifies the trigger meander to create the large meander in 2004. The Kuroshio takes offshore non-large meander paths for about a year from fall 2008. During this period deep anticyclone around Koshu Seamount was not developed enough to create the Kuroshio large meander since its path doesn’t pass over Koshu Seamount. Scatter plot of upper stretching term versus deep one computed in a box surrounding Koshu Seamount shows negatively-correlated tight relationship between them when the large meander happens, suggesting that baroclinic instability is an important process to create the large meander.
Park, J. H., Korea Ocean Research and Development Institute, Ansan, Republic Of Korea, jhpark@kordi.re.kr Watts, D. R., University of Rhode Island, Narragansett, USA, rwatts@gso.uri.edu
Poster presentation
Session #:084 Date: 2/21/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B2136
A NEW TURBULENT DIFFUSION BOX MODEL FOR ASSESSING CHEMODYNAMICS IN MARINE SURFACE WATERS: A PFOA TRANSPORT APPLICATION
A new mathematical model is developed and application demonstrated for perfluorinated octanoic acid (PFOA) diffusive transport in marine water. The traditional completely mixed media box-model is upgraded with an eddy diffusion coefficient and adjacent boxes coupled using the concept of “chemical flux continuity across interfaces” to produce the new model. All the while it retains the mass balance rigor and process simulation features of the traditional advective, transport, and reactive model. PFOA data at two oceanic sites fitted to a marine water-column 3-layer physical structure show the profiles of this tracer as being transport dominated. The model’s utility and versatility is further demonstrated by quantifying flux into surface waters, accumulation in marine layers and release to the abbys. Process-based and structured mathematical models provide the best theoretical option for unambiguous analysis of persistant organic pollutants (POPs) chemodynamics. The mathematical power of the turbulent diffusion box model (TDBM) will assure it applicability in further theoretical studies of chemical processes in this complex marine zone which should include for example, particle, phase-partitioning, bio-mediated transport, settling, reactions and products, physical-advective pumping, etc.
Thibodeaux, L. J., Louisiana State University, Baton Rouge, LA, USA, thibod@lsu.edu Lohmann, R. ., University of Rhode Island, Narragansett, RI, USA, lohmann@gso.uri.edu
Poster presentation
Session #:001 Date: 2/21/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
Presentation is given by student: No
PosterID: B1519
AN AIIR-SEA FLUX EXPERIMENT FOR 2030
In January 2011 the University of Rhode Island held a two day retreat for faculty and research scientists interested in where the field is going over the next 20 years. The retreat began with presentations detailing the current status and anticipated advances in genetics, nanotechnology, numerical modeling and robotics. Participants then outlined scientific problems that they expect will exist in 2030. This was followed by breakout sessions in which participants discussed experiments, based on anticipated technological advances, that might be undertaken in the 2030 time frame to address some of the identified problems. In this presentation we outline one of these experiments. The experiment was designed to quantify air-sea fluxes under high wind conditions following a wave train. We believe that not only will the processes involved remain poorly resolved in 2030 but also that they will become of increasing importance as the coupling and the spatial and temporal resolution of ocean and atmospheric models improves. The experiment outlined is based on a suite of unmanned submersible and air assets designed to sample the ocean, the atmosphere and the interface between the two.
Cornillon, P. C., University of Rhode Island, Narragansett, USA, pcornillon@me.com Farmer, D. ., Retired, Sydney, Canada, dfarmer@gso.uri.edu Roman, C. ., University of Rhode Island, Narragansett, USA, cnr@gso.uri.edu Ginis, I. ., University of Rhode Island, Narragansett, USA, iginis@gso.uri.edu Grilli, S. ., University of Rhode Island, Narragansett, USA, grilli@oce.uri.edu
Poster presentation
Session #:064 Date: 2/21/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B1074
REMOTE OBSERVATIONAL OCEANOGRAPHY USING SHIPS OF EXPLORATION AND SATELLITE/INTERNET2 TELEPRESENCE SYSTEMS
Telepresence technologies combined with high-bandwidth video/data streaming and online portals will bring vast quantities of information about the remote oceans to interested people worldwide. During the next 20 years, these technologies will empower scientists and educators to become deeply involved in observational oceanography in real time, facilitating the decision-making process and remote control of and interactivity with seagoing systems and instrumentation on remote platforms. The Inner Space Center (ISC) at the University of Rhode Island Graduate School of Oceanography works directly with two ships of exploration, the NOAA Ship Okeanos Explorer and the E/V Nautilus. During the 2010 and 2011 field seasons, the ISC helped support multiple expeditions onboard these platforms by enabling teams of scientists, students, and educators to take part in the field program remotely, providing access to video and data streams and facilitating remote ship-to-shore telecommunications. These capabilities have been tested and protocols have been refined for remote operations with high success, but with expected operational and technological challenges associated with this new paradigm. By 2030 we expect this new paradigm to be established and mainstreamed on many remote ocean observing and exploration systems.
Coleman, D. F., University of Rhode Island Graduate School of Oceanography, Narragansett, RI, USA, dcoleman@gso.uri.edu Elliott, K. P., NOAA Office of Ocean Exploration and Research, Silver Spring, MD, USA, kelley.elliott@noaa.gov Bell, K. C., Ocean Exploration Trust, Narragansett, RI, USA, katy@oceanexplorationtrust.org Martinez, C. ., NOAA Office of Ocean Exploration and Research, Narragansett, RI, USA, catalina.martinez@noaa.gov Ballard, R. D., University of Rhode Island Graduate School of Oceanography, Narragansett, RI, USA, rballard@gso.uri.edu
Poster presentation
Session #:064 Date: 2/21/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
PosterID: B1078
A GENE-BASED INDICATOR OF IRON LIMITATION IN THE DIATOM THALASSIOSIRA OCEANICA
Diatoms are abundant primary producers and key players in marine nutrient cycling. In several oceanic regions, diatoms are iron limited due to low atmospheric inputs. Under these conditions, many phytoplankton replace ferredoxin, an iron-rich photosynthetic electron transport protein, with the iron-free protein flavodoxin. Thalassiosira oceanica, a diatom isolated in the open ocean, has three flavodoxin gene copies. We determined the expression profiles of all flavodoxin copies and ferredoxin in laboratory cultures of T. oceanica grown in iron limiting conditions under continuous and cycling light. Quantitative RNA expression analysis confirmed that one of the T. oceanica flavodoxin copies was sensitive to iron; its expression was induced 1000- or 3000- fold in iron limited cells depending on light conditions. The expression of the two other flavodoxin copies and ferredoxin did not change significantly under the experimental conditions. We are analyzing the expression of flavodoxin in field samples collected from Northeast Pacific ocean where we have previously identified T. oceanica in diatom populations to determine whether flavodoxin expression can be used as a field-based indicator of Fe status in wild T. oceanica populations.
Darer, A. ., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, adarer@oberlin.edu Chappell, P. D., University of Rhode Island, Department of Cell and Molecular Biology, Kingston, USA, pdchappell@gmail.com Jenkins, B. D., University of Rhode Island, Department of Cell and Molecular Biology, Kingston, USA, jenkins.bethany@gmail.com
Poster presentation
Session #:149 Date: 2/21/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: A0122
RELATING TIDAL CYCLES OF STRATIFICATION, SHEAR, AND TURBULENCE TO ESTUARINE RESIDUAL FLOW
Tidal variability in estuaries commonly exceeds non-tidal residuals, yet is omitted from traditionally derived tidal-average momentum dynamics. Tidal correlation (TC) terms occur at lowest order and could cause substantial changes to the dynamics, strength, and even sense of residual flow. Relative phasing of tidal cycles in stratification, shear, and turbulence vary dramatically in space and time. Relative phasing control over TC terms and associated residual flow is examined using analytical models and an observational case study of Eastern Long Island Sound (LIS) near the estuary axis (moored CTD profiler records for stratification, and turbulent overturns using Thorpe-sorting; a ferry-mounted ADCP). Sensitivity to relative phases in the analytical model is underscored by the case study. In LIS near the bottom, stratification varies weakly and peak shear during flood apparently dominates turbulence characteristics. By contrast, in the upper water column tidal strain is active, with shear, stratification, and turbulent overturns all peaking during late ebb and slack after ebb; low Richardson numbers indicate shear drives enhanced turbulence during peak stratification, unlike in other systems where turbulence is suppressed by stronger ebb stratification.
Codiga, D. L., University of Rhode Island, Narragansett, USA, d.codiga@gso.uri.edu
Poster presentation
Session #:154 Date: 2/21/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1684
A COMPARISON OF FLUVIAL AND AEOLIAN TRANSPORTED BLACK CARBON TO DEEP MARINE SEDIMENTS IN THE EQUATORIAL ATLANTIC
BC is a resistant form of organic carbon that is ubitiquous to the marine environment since it is a byproduct of the incomplete combustion of biomass and fossil fuel burning. BC is deposited into the ocean through fluvial and Aeolian transport, but the magnitude of these two pathways has not been well studied since fluvial deposition is presumed to be the main mechanism. Two cores were analyzed for BC using an IRMS. Core 1a is situated in the fan of the Amazon River. The BC accounted for 35.5-91.6% of the total organic carbon (TOC) with the TOC and BC having an average δ13C of -21.0 and -31.5‰, respectively. Core 9a was taken in the open equatorial Atlantic basin, away from fluvial influence (07’26.721°N, 24’00.376°W). BC accounted for 20.3-49.9% of the TOC with TOC and BC having an average δ13C of -18.0 and -26.3‰, respectively. While Amazonian River deposition is a significant contributor of BC to marine sediments, Aeolian transported BC is still an important fraction that is needed in mass balance evaluations.
Pohl, K. A., Graduate School of Oceanography-University of Rhode Island, Narragansett, USA, kpohl@gso.uri.edu
Poster presentation
Session #:026 Date: 2/21/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: A0068
LATERAL AND INTRATIDAL VARIABILITY IN CURRENTS, HYDROGRAPHY, AND VERTICAL MIXING IN A WIDE ESTUARY.
Residual currents in estuaries can arise through a variety of non-linear mechanisms involving the covariance on tidal time scales between currents, stratification, and mixing. These processes are hypothesized to occur in the eastern portion of Long Island Sound (LIS), a wide, relatively deep estuary where tidal currents are strong. Measurements of currents from a hull-mounted ADCP and hydrography and conductivity microstructure from a towed undulating profiler along a repeated cross-estuary section show significant variability in current shear and stratification both laterally and over the tidal cycle. These observations and estimates of the gradient Richardson number and the vertical turbulent diffusivity will be presented in the context of assessing the tidal-period covariances among the variables and how these covariances change with lateral position. Results from a numerical simulation of the study area will be analyzed in the same fashion and compared to the observational results. An assessment of the relative importance of several different residual current generation mechanisms will be made for this region of eastern LIS.
Ullman, D. S., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, d.ullman@gso.uri.edu Codiga, D. L., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, dcodiga@gso.uri.edu Whitney, M. M., University of Connecticut, Department of Marine Sciences, Groton, USA, Michael.Whitney@uconn.edu
Poster presentation
Session #:154 Date: 2/21/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1686
BLACK CARBON IN THE SURFACE MIXED LAYER ACROSS THE NORTH ATLANTIC OCEAN
Black carbon (BC) and particulate organic carbon (POC) were determined in filter samples taken on EN 415, en route from Narragansett (RI), USA to Nice (France) in 2006. BC concentrations in surface water ranged from 2-11 µg L-1, while POC concentrations varied from 4-60 µg L-1. The fraction of BC was highest close to the U.S. East coast (up to 80% of POC), but decreased to < 20% in the Mediterranean. The BC’s 13 C isotope ratio shifted from heavier close to the U.S. East Coast (-10 to -14 ‰) towards values close to marine carbon near Europe (-20 to -21 ‰). Carbon 13 isotope ratios for POC were always in the range typically observed for marine carbon (-21 to -24 ‰). Measured BC concentrations in the surface water exceeded predictions (derived from a global circulation model) by one to two orders of magnitude.
Lohmann, R. ., University of Rhode Island, Narragansett, USA, lohmann@gso.uri.edu Pohl, K. ., University of Rhode Island, Narragansett, USA, kpohl@gso.uri.edu Sullivan, J. ., University of Rhode Island, Narragansett, USA, Sullivan.Julia@epamail.epa.gov Feichter, J. ., Max Planck Institute for Meteorology, Hamburg, Germany, johann.feichter@zmaw.de Kloster, S. ., Max Planck Institute for Meteorology, Hamburg, Germany, silvia.kloster@zmaw.de
Poster presentation
Session #:026 Date: 2/21/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: A0071
February 22, 2012
PROPAGATION OF SST ANOMALIES ALONG THE NORTH PACIFIC POLAR FRONT AND THEIR IMPACT ON THE GULF OF ALASKA, ALEUTIANS, AND BERING SEA ECOSYSTEMS
Propagation of SST anomalies along the North Pacific Polar Front (NPPF) in 1930-2010 was studied from Hadley 1-degree climatology. The Polar Front Current associated with the NPPF acts as a conduit of oceanic anomalies originating in the NW Pacific. These anomalies propagate eastward along the NPPF into the Gulf of Alaska where the NPPF retroflects and extends westward along the shelf break to the Aleutians and into the Bering Sea. Thus, the Polar Front Current connects ecosystems of the West and East Subarctic Gyres, Aleutians, and Bering Sea. Sporadic breakdowns of the along-front connectivity transpire as concurrent anomalies of opposite signs in the Western and Eastern Pacific Subarctic. The Polar Front Current carries relatively warm waters into the Gulf of Alaska and toward the Aleutians; therefore, intensification (relaxation) of the Polar Front Current results in warming (cooling) of the high-latitude Northeast Pacific. Intensity of along-front advection varied on seasonal, interannual, and decadal scales, with a maximum in 1956-1966 and a minimum afterwards through 1976. Regime shifts of 1976-1977 and 1988-1989 manifested as cross-Pacific transpositions of cold epochs.
BELKIN, I. M., UNIVERSITY OF RHODE ISLAND, Narragansett, RI, USA, igormbelkin@gmail.com SHOTWELL, S. K., Ted Stevens Marine Research Institute, Juneau, AK, USA, Kalei.Shotwell@noaa.gov
Poster Presentation
Session #:142 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B2229
OCEANIC THERMAL FRONTS AND NET PRIMARY PRODUCTION ASSOCIATED WITH LONGLINE CATCHES OF ALBACORE TUNA (THUNNUS ALALUNGA) IN THE SOUTHERN INDIAN OCEAN
In this fishery oceanographic study, we investigated the catches and distributions of albacore tuna (ALB) in relation to sea surface temperature (SST), SST fronts, and net primary production (NPP) in the Indian Ocean. A combination of SST, SST fronts (SST gradient magnitude (GM)), NPP, and set longline fishery data were proven to be key for detecting regions with high potential for ALB. The main fishing grounds are mainly concentrated in the southern Indian Ocean, and the fishing season is from June to September. High catch per unit effort (CPUEs) (>8 fish/103 hooks) were concentrated in the area with SSTs of 16~20 °C, which are close to the northern zonal band of the Subtropical Front. Histograms of high CPUEs plotted against SST, SST GM, and NPP indicated that high CPUEs were in an SST range of 16.5~19 °C and in an NPP range of 300~500 mg C/m2/d. Although most of the high CPUEs occurred in areas with SST GMs of 0.1~0.3 °C/10 km, there were still many high catches located in areas with higher SST GM values. The small distances between latitudinal mean positions of the optimal SST and NPP range contour lines were also considered to be a good indicator for predicting areas of higher ALB abundances.
Lan Kuo-Wei , L. K., Department of Environmental Biology Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan ROC, aaman72422@msn.com Chang Yi , C. Y., Department of Environmental Biology Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan ROC, jeche7058@msn.com Lee Ming-An, L. M., Department of Environmental Biology Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan ROC, Keelung Belkin Igor , B. I., Graduate School of Oceanography, University of Rhode Island,, Narragansett, USA, igormbelkin@gmail.com Nishida Tom , N. T., National Research Institute of Far Seas Fisheries, Fisheries Research Agency, Shizuoka, Japan, tnishida@affrc.go.jp
Poster presentation
Session #:142 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B2209
FUTURE OCEAN USES IMPORTANT FOR COASTAL AND MARINE SPATIAL PLANNING
There is a need to conserve ocean ecosystems and use ocean space, requiring planning for multiple uses of compatible activities and development of strategies to promote, enhance, and optimize these uses. The Rhode Island Ocean Special Area Management Planning (OSAMP) process is an ecosystem-based planning framework with unique policy drivers. The OSAMP also informs implementation actions for future multiple uses of ocean space. The OSAMP reviewed possible future uses and conservation issues for Block Island and Rhode Island Sounds: mining, offshore LNG, short sea shipping, marine conservation, artificial reefs, aquaculture development, expansion of ecotourism and underwater cemeteries, and use as a research/education area. Principles and practices of ecological engineering, industrial ecology, life cycle assessments and material flow accounting, as well as social ecology and ecological economics will be important to the design, implementation, and evaluation of compatible, multiple uses of ocean space. There will also be a rapid turnover of ideas on the future uses of ocean space; thus, a participatory framework for the engagement of stakeholders must continue as new uses are explored so that all information can be shared systematically.
http://www.seagrant.gso.uri.edu/
Costa-Pierce, B. A., University of Rhode Island, Narragansett, USA, bcp@gso.uri.edu McCann, J., University of Rhode Island, Narragansett, USA, mccann@gso.uri.edu
Poster presentation
Session #:131 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1065
UPPER-LOWER LAYER COUPLING IN LOOP CURRENT EDDIES EKMAN AND FRANKLIN
Arrays of moored current meters and bottom mounted pressure equipped inverted echo sounders (PIES) centered near 26°N, 87°W were deployed in April 2009. Data were recovered via mooring rotation or telemetry in July and November 2010. Two Loop Current Eddies form during the 15-month observational period: Eddy Ekman in summer 2009 and Eddy Franklin in summer 2010. Lower-layer flows are not visually coherent with upper-layer Loop Current flows, and the principal axes of the standard deviation ellipses and the mean vectors are not, in general, aligned with those of the surface layer. In both detachment events, a marked increase in lower-layer eddy kinetic energy occurs coincident with the development of a large-scale meander along the northern and eastern parts of the Loop Current front. Lower-layer eddies develop in a pattern reminiscent of developing baroclinic instabilities. These growing and southward propagating meanders along the west Florida slope appear to be the major mechanism that causes these eddies to initially detach.
Donohue, K. A., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, kdonohue@gso.uri.edu Leben, R. ., University of Colorado, Boulder, USA, leben@colorado.edu Hamilton, P. ., SAIC, , USA, peter.hamilton@saic.com Watts, D. R., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, rwatts@gso.uri.edu
Poster presentation
Session #:113 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1331
CYCLONE DEVELOPMENT DURING THE DETACHMENTS OF LOOP CURRENT EDDIES EKMAN AND FRANKLIN: A HISTORICAL PERSPECTIVE.
Moored arrays, measuring currents, temperature and salinity, were deployed in the deep Eastern Gulf of Mexico between the west Florida slope and the Campeche Bank in April-May 2009, with mooring rotations in the summer 2010. During the summers of 2009 and 2010, two Loop Current (LC) eddies formed, named Ekman and Franklin, respectively. The initial detachments produced large LC eddies that were in a more southern location than is typical of many separations, and thus free passage to the western Gulf was blocked by the Campeche Bank, apparently allowing the observed multiple detachment-reattachment cycles before the ultimate separations. The events leading to the initial detachments of both eddies were very similar with large meander crests and troughs, with wavelengths of several hundred kilometers, developing on the east side of an extended LC that developed into a strong cyclone between the eddy and the LC in its southern port-to-port mode. Meanders were initiated by large cyclones north of the LC, in both cases. Details of these eddy formations and detachments are compared to the historical altimeter record.
Hamilton, P. ., Science Applications International Corporation, Raleigh, NC, USA, peter.hamilton@saic.com Leben, R. R., CCAR, University of Colorado, Boulder, USA, leben@colorado.edu Donohue, K. A., GSO, University of Rhode Island, Narragansett, USA, kdonohue@gso.uri.edu Sheinbaum, J. ., CICESE, Ensenada, Mexico, julios@cicese.mx Candela, J. ., CICESE, Ensenada, Mexico, jcandela@cicese.mx
Poster presentation
Session #:113 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1332
PERFORMANCE EVALUATION OF HYCOM GULF OF MEXICO MODEL
In 2009, a comprehensive field study began, aimed to investigate Loop Current circulation dynamics, eddy-shedding mechanisms, and forcing of lower-layer flows in the Gulf of Mexico. This study utilized a mapping array centered near 26°N 87°W, which consisted of 9 full-depth and 7 near-bottom moorings as well as 25 bottom-mounted pressure equipped inverted echo sounders. Moorings were deployed in April 2009 and data recovered via rotation or telemetry in July and November 2010. Measurements were compared to output from the 1/25th degree resolution Gulf of Mexico HYCOM model with data assimilation. Model-to-mooring comparison revealed high temperature correlations and moderate to high correlations for both zonal and meridional velocity, with array-averaged correlations in the thermocline of 0.83, 0.71, and 0.79, respectively. Time-averaged eddy kinetic energy (EKE) showed comparable, but higher, values of deep EKE in the mooring array. A case study of upper and lower layer flows during the separation of Loop Current Eddy Franklin showed similar features between model and mooring array. In particular, both indicate that deep cyclones are generated beneath the Loop Current during the separation process.
Rosburg, K. ., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, rosburk@students.wwu.edu Donohue, K. A., University of Rhode Island, Graduate School of Oceanography, Narragansett, USA, kdonohue@gso.uri.edu Chassignet, E. ., Florida State University, Dept. of Oceanogrpahy, Tallahassee, USA, echassignet@coaps.fsu.edu
Poster presentation
Session #:113 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1333
EDDIES AS A SOURCE OF STRIATIONS IN TIME-AVERAGED SEA LEVEL ANOMALY
Eddies are investigated as the source of quasi-zonal patterns, or striations, in zonal geostrophic velocity (Ug) estimated from time-averaged sea level anomaly (SLA). Distinct four-year averages of SLA during 1993−2008 reveal striations in Ug estimated from time-averaged SLA in the South Pacific (20−50oS, 200−280oE). Striations are characterized by speeds O(1 cm s-1), are separated meridionally by 200 km and appear to alternate in direction. Such patterns are similar to those observed in Ug estimated from mean dynamic topography and Argo float measurements. Use of an eddy database in conjunction with a contour-identification and eddy removal algorithm demonstrates that quasi-zonal patterns are primarily the result of propagating eddies. Eddies account for 50−80% of the energy in the total observed Ug field and correlation coefficients between total observed and eddy-only Ug are 0.87−0.94. The latter illustrates that locations of striations match those created by eddies while the former allows for the existence of latent energy. Striations in sea surface temperature are also explored. Some attention is given to the abilities of the tracking and contour-identification/eddy removal algorithms to identify all eddy energy.
Buckingham, C. E., Graduate School of Oceanography / University of Rhode Island, Narragansett, USA, cbuckingham@gso.uri.edu Cornillon, P. C., Graduate School of Oceanography / University of Rhode Island, Narragansett, USA, pcornillon@gso.uri.edu
Poster presentation
Session #:133 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B2195
DEEP OVERFLOW THROUGH THE KERAMA GAP CONNECTING THE EAST CHINA SEA AND THE PHILIPPINE SEA
The East China Sea includes the Okinawa Trough (in part deeper than 2000 m) between the continental slope and the Ryukyu Islands. In the Okinawa Trough, thermocline waters are exchanged with those of the Philippine Sea via the Kuroshio, while the deep waters below the thermocline can be exchanged only through the Kerama Gap with a sill depth of 1100 m. This study reveals temporal and spatial velocity-structures below the thermocline over the the Kerama Gap, cross-section mainly using data from moored current-meters during 2009/06–2011/06 and supplemented with outputs from a data-assimilated daily model provided by the Naval Research Laboratory. The temporal mean velocity field reveals a steady deep flow (> 10 cm/s) into the Okinawa Trough, which is clearly intensified on the northern slope of the Kerama Gap. The model outputs suggest that the deep flow is a branch of the Ryukyu Current, which is a deep current flowing northeastward along the eastern slope of the Ryukyu Islands. Most strong variations of the deep flow in the Kerama Gap are ascribed to unstable motions of the Ryukyu Current.
Nakamura, H. R., Kagoshima University, Kagoshima, Japan, nakamura@fish.kagoshima-u.ac.jp Liu, Z. ., Kagoshima University, Kagoshima, Japan, lzjchina2010@hotmail.com Nishina, A. ., Kagoshima University, Kagoshima, Japan, nishina@fish.kagoshima-u.ac.jp Wimbush, M. ., University of Rhode Island, Narragansett, USA, mwimbush@gso.uri.edu Park, J. H., Korean Ocean Research and Development Institute, Ansan, Republic Of Korea, jhpark@kordi.re.kr
Poster presentation
Session #:084 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B2146
NEW FRONTIERS IN OCEAN EXPLORATION: THE 2010 AND 2011 E/V NAUTILUS FIELD SEASONS
The Exploration Vessel NAUTILUS is creating a focus of international leadership for the development and integration of leading-edge technologies, educational programs, field operations, and public outreach programs for ocean exploration, in partnership with NOAA, National Geographic Society, Office of Naval Research, Sea Research Foundation and other sponsors. To do so, the program uses a complement of deep submergence vehicle systems and telepresence technologies to engage scientists, educators and the public, both at sea and ashore, allowing them to become integral members of the on-board exploration team. Two four-month field seasons were undertaken aboard NAUTILUS (2010-2011) to the Black, Aegean and Mediterranean Seas, and North Atlantic Ocean. During these expeditions, a number of archaeological, biological and geological discoveries were made while broadcasting the events live on the internet to thousands of viewers. When discoveries are made, experts ashore are notified and brought aboard virtually within a short period of time to help guide shipboard response before the ship moves on. Future expeditions will expand our network of “Doctors on Call” to engage the widest scientific audience possible.
http://www.nautiluslive.org
Bell, K. L., Ocean Exploration Trust, Lyme, USA, katy@oceanexplorationtrust.org Ballard, R. D., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, rballard@gso.uri.edu Coleman, D. F., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, dcoleman@gso.uri.edu Roman, C. N., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, cnr@gso.uri.edu Brennan, M. L., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, mlbrennan@gso.uri.edu
Poster presentation
Session #:063 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1168
EFFECTS OF BIO-PHYSICAL INTERACTIONS ON PARTICLE DISTRIBUTIONS REVEALED BY IN SITU DIGITAL HOLOGRAPHY, ADAPTIVE SAMPLING AND PROFILING OF BULK WATER PROPERTIES
Cinematic digital holograms recorded by the free drifting 'HoloSub', simultaneous measurements of density, chlorophyll and light scattering, and adaptive sampling were used to characterize the particle population and flow in the water column in East Sound, WA. A 20,000 hologram up cast provided vertical profiles of shear strain and dissipation rates, size distributions of species, and orientation of diatom chains. Key results include: (a) formation of multiple 10-20cm thick layers of small particle with broad horizontal extents, in regions of low local shear/dissipation, (b) an intense phytoplankton layer occurred at the base of a stable pycnocline, and primarily contained diatom cells, detritus and Chaetoceros socialis colonies with ~4×106 cells/mL; (c) zooplankton avoided layers with high concentrations of C. socialis colonies and/or particles; (d) diatom chains had a near-horizontal alignment at the pycnocline base, and shallow angles in other low shear regions, but were randomly oriented in regions of high shear, consistent with theories; (e) size distribution of small particles had power laws with varying exponents, while diatom chain and C. socialis colony sizes had log-normal distributions.
Talapatra, S. ., Johns Hopkins University, Baltimore, USA, talapatra@jhu.edu Hong, J. ., Johns Hopkins University, Baltimore, USA, jhong22@jhu.edu McFarland, M. ., University of Rhode Island, Narragansett, USA, malcolm@gso.uri.edu Nayak, A. ., Johns Hopkins University, Baltimore, USA, aditya.nayak@gmail.com Cao, Z. ., Johns Hopkins University, Baltimore, USA, zhangcao1984@gmail.com Katz, J. ., Johns Hopkins University, Baltimore, USA, katz@jhu.edu Sullivan, J. ., WET labs, Narragansett, USA, jims@wetlabs.com Twardowski, M. ., WET labs, Narragansett, USA, mtwardo@wetlabs.com Rines, J. ., University of Rhode Island, Narragansett, USA, jrines@gsosun1.gso.uri.edu Donaghay, P. ., University of Rhode Island, Narragansett, USA, donaghay@gso.uri.edu
Poster presentation
Session #:144 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1206
SCANNING FLOW CYTOMETRIC ANALYSIS OF THE MORPHOLOGICAL AND BIO-OPTICAL CHARACTERISTICS OF HETEROGENEOUS MARINE PHYTOPLANKTON COMMUNITIES
Marine phytoplankton communities comprise numerous species with distinct morphological characteristics such as cell size, shape and intracellular structure, which are fundamental to their complex ecology. Although lab and modeling studies have shown that morphological characteristics can affect the optical properties of cells and their ability to absorb light for photosynthesis, testing these models in natural communities requires simultaneous measurement of optical properties and morphology at the community and individual cellular levels. We examined the optical and morphological characteristics of natural phytoplankton communities in East Sound, WA using bulk optical measurements (WET Labs ac9 and bb3) and scanning flow cytometric analysis of individual particles (CytoBuoy). High resolution optical profiles were used to guide sample collection from distinct phytoplankton communities. Flow cytometric analysis of samples revealed dramatic variation of the size/abundance distributions of phytoplankton and non-algal particles, the distribution of chlorophyll among cell size classes, and their relative contribution to total absorption or scattering. Comparison with optical properties suggests that large cells with complex morphological structure may increase their light absorption efficiency and minimize package effects by enhanced scattering of incident light.
McFarland, M. N., University of Rhode Island, Narragansett, USA, malcolm@gso.uri.edu Rines, J. ., University of Rhode Island, Narragansett, USA, jrines@gso.uri.edu Donaghay, P. L., University of Rhode Island, Narragansett, USA, donaghay@gso.uri.edu Sullivan, J. M., WET Labs, Inc., Narragansett, USA, jims@wetlabs.com
Poster presentation
Session #:144 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1209
RECENT ADVANCES AND CHALLENGES IN USING ADAPTIVE SAMPLING TO QUANTIFY PROCESS AND TEST OCEANOGRAPHIC HYPOTHESIS
There has been a growing recognition over the last 20 years that the biological, biogeochemical, and optical dynamics of marine systems are frequently dominated by episodic events or by processes that are spatially concentrated in regions of strong gradients such as those observed in chemoclines, thin layers and fronts. Although much of the progress in this area has been dominated by the use of adaptive sampling to guide the collection of discrete samples from ships for laboratory analysis, recent advances in sensors, deployment systems and near-real time data analysis has opened the door for the autonomous collection and analysis of these samples in situ. Herein, we will first use autonomous profiler data collected during a storm experiment to illustrate the need for new in situ adaptive sampling approaches for quantifying critical processes and testing hypothesis. We will then consider how these challenges might be overcome by incorporating some of the advanced sensors illustrated in other talks in this session into ocean observing systems and then using them to adaptively sample structures and processes at the critical time and space scales needed to test hypotheses.
Donaghay, P. L., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, donaghay@gso.uri.edu
Poster presentation
Session #:144 Date: 2/22/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1208
February 23, 2012
IN SITU PREY INGESTION AND EGG PRODUCTION BY THE CTENOPHORE MNEMIOPSIS LEIDYI IN NARRAGANSETT BAY, RI, USA
The ctenophore Mnemiopsis leidyi inhabits coastal environments of highly variable prey composition. For example, within Narragansett Bay, prey fields within embayments are often dominated by meroplankton while open bay stations are dominated by copepods. Mnemiopsis occupies both regions and may be advected between different the differing prey regimes. How do different prey regimes influence population growth? We combine temperature-dependent metabolic rates with estimates of carbon intake based on situ gut contents to estimate overall carbon balance on a weekly basis for Mnemiopsis from three sites in Narragansett Bay over two years. The calculated carbon balance is then compared to egg production rates for corresponding periods. Our intent is to use this data to evaluate three questions: first, how does the carbon balance of Mnemiopsis vary through time and space, second, does the carbon balance coincide with egg production, and third, does the type of prey (meroplankton vs copepod) correspond with field egg production rates?
Lang, C. ., SUNY Stony Brook, Stony Brook, USA, clang2@friars.providence.edu Ciobanu, A. ., Providence Colleg, Providence, USA, aciobanu@friars.providence.edu Costello, J. H., Providence College, Providence, USA, costello@providence.edu Sullivan, B. K., University of Rhode Island, Narragansett, USA, bsullivanwatts@gmail.com
Poster presentation
Session #:177 Date: 2/23/2012 Time: 10:30 - 12:30 Location: Poster/Exhibit Hall
PosterID: A0538
IDENTIFICATION AND CHARACTERIZATION OF DNA FINGERPRINTING MARKERS FOR THE BLOOM-FORMING DIATOM, THALASSIOSIRA GRAVIDA
The diatom Thalassiosira gravida forms large blooms in sub-polar and polar regions that are important for global biogeochemical cycling, including the North Atlantic and Southern Oceans. The genetic diversity of these open ocean blooms will influence their ability to respond to different selection pressures, including those brought on by a changing climate. Microsatellites are ideal for examining intraspecific genetic diversity, given their relatively fast mutation rates and high heterozygosities. To identify microsatellites in T. gravida, we tested primers that were optimized for four microsatellite loci in the closely-related diatom, T. rotula. Two loci were dinucleotide repeats and two were trinucleotide repeats. Of those, only loci containing trinucleotide repeats could be amplified in T. gravida. Initial results indicate that these loci may be polymorphic and can thus be used to identify genetically distinct clonal lineages of T. gravida. We are currently amplifying these loci as well as sequencing the rDNA from single cell isolates collected from the Iceland Basin, the Labrador Sea, and the Gulf of Maine to quantify the genetic diversity associated with blooms of T. gravida.
McCusker, K. A., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, ktmccusk@gmail.com Rynearson, T. A., University of Rhode Island Graduate School of Oceanography, Narragansett, USA, rynearson@gso.uri.edu
Poster presentation
Session #:152 Date: 2/23/2012 Time: 14:00 - 16:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: A0378
DIVERGENT EDDY HEAT FLUXES IN THE KUROSHIO EXTENSION 143O-149OE
From observations made during the Kuroshio Extension System Study (KESS), 16-month mean maps of eddy heat fluxes were quantified using an array of current and pressure equipped inverted echo sounders (CPIES). Weakly depth-dependent geostrophic currents, measured in the deep ocean, are responsible for driving divergent eddy heat fluxes across the upper-ocean front. The vertical coupling between the deep and upper ocean is the process responsible for these dynamically-important eddy heat fluxes. Fluxes are strongest near the mean path of the jet and are vertically coherent, with extrema exceeding 500 kW m-2 near 400 m depth. The fluxes change alongstream from downgradient-to-upgradient at the mean trough axis. The mean spatial structure results from episodic and varied mesoscale processes: a cold-core ring formation, two ring-jet interactions, frontal meanders that grow and decay, and topographically-controlled weakly depth-dependent eddies that couple to the jet in the 30-60 day band.
Bishop, S. P., University of Rhode Island, Narragansett, USA, sbishop@gso.uri.edu Watts, D. R., University of Rhode Island , Narragansett, USA, rwatts@gso.uri.edu Donohue, K. A., University of Rhode Island, Narragansett, USA, kdonohue@gso.uri.edu
Poster presentation
Session #:020 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1399
THE SLOWLY VARYING MEAN KUROSHIO EXTENSION CURRENT TRANSPORT FROM SEA SURFACE TO SEA FLOOR
Centered near 35N, 146E east of Japan, the Kuroshio Extension System Study (KESS) moored a 550 X 550 km grid of current-and-pressure-recording inverted echo sounders. The array observed the time-varying horizontal current structure along its mean path and within the neighboring recirculations. Mapped total-transport streamlines distinguish the through-flowing portion of the Kuroshio from closed recirculations. An anticyclonic southern recirculation gyre (SRG) is centered near 34.5N, 144E. The northern recirculation gyre is downstream from the KESS array, and within KESS a northern local cyclonic recirculation exists within the trough but is not treated further here. Six-month and ten-month mean transport-maps are calculated respectively over stable and energetic-meandering intervals (units Sverdrup): Stable-regime combined total transport is 133, comprising 57 throughflow and 76 SRG; the baroclinic components are respectively 98, 69 and 29. Unstable-regime combined total transport is 106, comprising 55 throughflow and 51 SRG; the baroclinic components are respectively 78, 41 and 37. Total transport, SRG strength, and baroclinic total and throughflow decrease in the unstable regime.
http://www.po.gso.uri.edu/dynamics/
Watts, D. R., University of Rhode Island, Narragansett, RI, USA, rwatts@gso.uri.edu Donohue, K. A., University of Rhode Island, Narragansett, RI, USA, kdonohue@gso.uri.edu Tracey, K. L., University of Rhode Island, Narragansett, RI, USA, ktracey@gso.uri.edu
Poster presentation
Session #:020 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1400
DEEP EDDIES MODULATE FRONTAL MEANDER GROWTH IN THE KUROSHIO EXTENSION
During the Kuroshio Extension System Study (KESS) a two-dimensional array of current-and-pressure-recording inverted echo sounders provided synoptic measurements of upper and deep fluctuations in the Kuroshio Extension between 143oE and 149oE with mesoscale resolution. Downstream-propagating frontal meanders, also called frontal waves, with periods of 3-60 d were always present between June 2004 and September 2005. Most meanders did not grow systematically downstream. Instead, meanders alternately grew and decayed as they propagated over distances of 100-200 km. Interaction with deep eddies, having a nearly depth-independent current structure, caused this growth or decay. These remotely-generated eddies propagated into the region from the northeast and east, thus tending to cross or oppose the meanders in the upper jet. Upper meanders and deep eddies jointly intensified when they encountered each other with the deep eddy offset about a quarter wavelength ahead of the upper meander, which is the orientation favorable to baroclinic instability. Subsequently as the upper and deep features moved past each other and the vertical offset changed, intensification ceased.
Tracey, K. L., University of Rhode Island, Narragansett, USA, ktracey@gso.uri.edu Watts, D. R., University of Rhode Island, Narragansett, USA, rwatts@gso.uri.edu Donohue, K. A., University of Rhode Island, Narragansett, USA, kdonohue@gso.uri.edu
Poster presentation
Session #:020 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1413
DISTRIBUTION AND PHYSIOLOGY OF THECOSOME PTEROPODS IN THE EASTERN TROPICAL PACIFIC: A NATURAL EXPERIMENT IN CO2 EXPOSURE
Thecosomatous pteropods are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because of their aragonitic shells. Despite this concern, there is very little known about the distribution of these animals in relation to regions of naturally high CO2. This study examines the distribution of thecosome pteropods in the Eastern Tropical Pacific above an oxygen minimum zone. In this location carbon dioxide levels reach ~1000 ppm and aragonite is undersaturated at >200m. To explore the physiological sensitivity of pteropods in the region to CO2, we used end-point respiration experiments that measured the oxygen consumption and ammonia excretion of five pteropod species under conditions of normocapnia (390 ppm) and hypercapnia (1000 ppm). Depth stratified net samples show that several species of pteropod naturally migrate into hypercapnic oxygen minimum zones. The oxygen consumption and ammonia excretion of these migratory species was not affected by CO2 treatments. Non-migratory species responded to high CO2 conditions with reduced oxygen consumption and ammonia excretion. This indicates that the natural chemical environment of individual species influences their resilience to ocean acidification.
Maas, A. E., Woods Hole Oceanographic Institution, Woods Hole, USA, amaas@whoi.edu Wishner, K. F., GSO, University of Rhode Island, Narragansett, USA, kwishner@gso.uri.edu Seibel, B. A., University of Rhode Island, Kingston, USA, seibel@uri.edu
Poster presentation
Session #:056 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: A0214
PROJECTED CHANGES IN THE PACIFIC SUBTROPICAL MODE WATERS UNDER GLOBAL WARMING
Global warming may change the formation and evolution pathways of the Subtropical Mode Waters (STMW) in the Pacific Ocean. This study investigates the changes by comparing solutions from a set of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) models between a present-day climate (the 20C3M experiments) and a future, warmer climate (the SRESA1B experiments). Under the warmer climate scenario, the STMW in the North Pacific are produced on lighter isopycnal surfaces and are significantly weakened in terms of their formation and evolution. These changes are due to a more stratified upper ocean and thus a shoaling of the winter mixing depth resulting mainly from a reduction of the ocean-to-atmosphere heat loss over the subtropical region. In sharp contrast, however, the warmer climate induces a significantly increased volume of the South Pacific Eastern Subtropical Mode Water (SPESTMW) resulting mainly from an intensification of the southeast trade winds.
Luo, Y., University of Rhode Island, Narragansett, USA, yluo@gso.uri.edu Liu, Q., Ocean University of China, Qingdao, China, liuqy@ouc.edu.cn Rothstein, L. ., University of Rhode Island, Narragansett, USA, lrothstein@gso.uri.edu
Poster presentation
Session #:106 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
PosterID: B1606
KUROSHIO EXTENSION MEANDERS: MODEL DATA-INTERCOMPARISON
Recent analysis from the Kuroshio Extension System Study, KESS, quantifies the frequency, wavelength and growth of Kuroshio Extension meanders between 143°E and 149°E with periods 3-60 days. Comparable analysis is performed on output from the high-resolution global Hybrid Coordinate Ocean Model (HYCOM) circulation model. Two model simulations are considered, one with data assimilation (``assimilation’’) and one without data assimilation (``free’’). Propagation speeds estimated along the Kuroshio Extension path from both simulations produce similar results to the KESS study; however, the assimilative run shows slightly longer wavelengths than the observations or the free run. KESS observations indicate that the interaction between Kuroshio Extension meanders and external westward propagating barotropic eddies are important for the local intensification of Kuroshio Extension meanders. Both model runs have westward propagating barotropic anomalies that interact with meanders. Sea surface height variance along the mean Kuroshio Extension path between 143°E to 155°E is about 4 times larger for both the baroclinic and barotropic sea surface height in the assimilation run compared to the free run.
Zamorski, S. E., URI , Narragansett, USA, szamorski@gso.uri.edu
Donohue, K. A., URI , Narragansett, USA, kdonohue@gso.uri.edu
Poster presentation
Session #:020 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: B1417
SEASONAL 210PO AND 210PB DISTRIBUTIONS AND PLANKTON COMMUNITY STRUCTURE IN THE NE PACIFIC
The 210Po and 210Pb natural radionuclide pair has been studied increasingly as a tracer for particulate organic carbon due to the preferential removal of 210Po by biota relative to its grandparent 210Pb. In this study, we investigated the seasonal distribution of 210Po and 210Pb in the upper 500m of the North Pacific Subarctic Ocean in relation to plankton community using data from seawater, sediment traps, pumps, and plankton nets. This is the first 210Po/210Pb data set presented for Line P and Ocean Station Papa (OSP). Preliminary results indicate that dissolved polonium activity profiles reflect temporal and spatial changes in zooplankton and phytoplankton community composition. 210Po profiles are unexpectedly similar from the highly productive coast of Vancouver to the HNLC area near OSP. We will interpret particulate and dissolved 210Po/210Pb results including deficits and remineralization depths in the context of plankton community dynamics.
Choi, H. Y., Queens College, CUNY, Flushing, USA, hiuyanchoi@gmail.com
Stewart, G. M., Queens College, CUNY, Flushing, USA, gstewart@qc.cuny.edu
Lomas, M. W., Bermuda Institute of Ocean Sciences, , Bermuda, Michael.lomas@bios.edu
Moran, S. B., Grad School of Oceanography, URI, Narragansett, USA, moran@gso.uri.edu
Kelly, R. P., Grad School of Oceanography, URI, Narragansett, USA, rokelly@gso.uri.edu
Poster presentation
Session #:147 Date: 2/23/2012 Time: 17:00 - 18:00 Location: Poster/Exhibit Hall
Presentation is given by student: Yes
PosterID: A0275
