Oceanography Commons^™

Eddy Correlation Measurements Of The Air/Sea Flux Of Dimethylsulfide Over The North Pacific Ocean, Christa A. Marandino, Warren J. De Bruyn, Scott D. Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Shipboard measurements of air/sea fluxes and sea surface concentrations of dimethylsulfide (DMS) were made over the tropical and midlatitude North Pacific Ocean. Atmospheric pressure chemical ionization mass spectrometry was used to measure DMS levels in ambient air and in air equilibrated with surface seawater drawn from a depth of 5 m. Air/sea fluxes were obtained using eddy covariance. Corrections and uncertainties involved in the calculation of fluxes from shipboard data are discussed. The surface ocean DMS concentrations measured during this study ranged from 1 to 10 nM, and atmospheric mixing ratios ranged from 20 to 1000 ppt. Air/sea fluxes ranged …

Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 1. Model Configuration And Ecosystem Dynamics, Baris Salihoglu, Eileen E. Hofmann

OES Faculty Publications

The primary objective of this research is to investigate phytoplankton community response to variations in physical forcing and biological processes in the Cold Tongue region of the equatorial Pacific Ocean at 0N, 140W. This research objective was addressed using a one-dimensional multicomponent lower trophic level ecosystem model that includes detailed algal physiology, such as spectrally-dependent photosynthetic processes and iron limitation on algal growth. The ecosystem model is forced by a one-year (1992) time series of spectrally-dependent light, temperature, and water column mixing obtained from a Tropical Atmosphere-Ocean (TAO) Array mooring. Autotrophic growth is represented by five algal groups, which have …

Iron In Ice Cores From Law Dome: A Record Of Atmospheric Iron Deposition For Maritime East Antarctica During The Holocene And Last Glacial Maximum, Ross Edwards, Peter N. Sedwick, Vin Morgan, Claude Boutron

OES Faculty Publications

Total dissolvable iron (TDFe) was measured in sections of ice cores recovered from Law Dome on the coast of Wilkes Land, East Antarctica. These samples include ice dating from the Last Glacial Maximum (LGM), the Last Deglaciation, and the early and mid Holocene as well as samples from the Anthropocene that have been dated with seasonal to annual resolution. Combining our TDFe concentration data with estimates of the ice accumulation rate, we estimate the atmospheric iron deposition for Law Dome and the adjacent Southern Ocean during these periods. Our results indicate that the atmospheric iron deposition flux to this region …

Estimation Of Iron Solubility From Observations And A Global Aerosol Model, Chao Luo, N. M. Mahowald, N. Meskhidze, Y. Chen, R. L. Siefert, A. R. Baker, Anne M. Johansen

All Faculty Scholarship for the College of the Sciences

Mineral aerosol deposition is the dominant source of iron to the open ocean. Soil iron is typically insoluble and understanding the atmospheric processes that convert insoluble iron to the more soluble forms observed over the oceans is crucial. In this paper, we model several proposed processes for the conversion of Fe(III) to Fe(II), and compare with cruise observations. The comparisons show that the model results in similar averaged magnitudes of iron solubility as measured during 8 cruises in 2001–2003. Comparisons show that results of cases including cloud, SO₂ and hematite processing are better than the other approaches used using …

Coupled Oceanic-Atmospheric Variability And U.S. Streamflow, Glenn A. Tootle, Thomas C. Piechota, Ashok Singh

Civil and Environmental Engineering and Construction Faculty Research

A study of the influence of interdecadal, decadal, and interannual oceanic-atmospheric influences on streamflow in the United States is presented. Unimpaired streamflow was identified for 639 stations in the United States for the period 1951–2002. The phases (cold/negative or warm/positive) of Pacific Ocean (El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO)) and Atlantic Ocean (Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO)) oceanic-atmospheric influences were identified for the year prior to the streamflow year (i.e., long lead time). Statistical significance testing of streamflow, based on the interdecadal, decadal, and interannual oceanic-atmospheric phase (warm/positive or cold/negative), was performed by …

Biophysical Mechanisms Of Larval Fish Ingress Into Chesapeake Bay, Jonathan A. Hare, Simon Thorrold, Harvey Walsh, Christian Reiss, Arnoldo Valle-Levinson, Cynthia Jones

OES Faculty Publications

Selective tidal stream transport is hypothesized as a dominant mechanism by which larvae of marine animals move through estuarine openings. For larvae moving from the shelf to estuarine habitats, selective tidal stream transport proposes that larvae are higher in the water column during flood tide and lower in the water column during ebb tide. Although a number of studies conclude that selective tidal stream transport is the mechanism responsible for larval ingress, few studies consider alternative mechanisms or consider passive explanations for tidal patterns in larval distributions. We examined the biophysical mechanisms responsible for larval ingress into Chesapeake Bay using …

An Exercise In Forecasting Loop Current And Eddy Frontal Positions In The Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, George Forristall, C. Cooper, Steven Dimarco, S. Fan

CCPO Publications

As part of a model-evaluation exercise to forecast Loop Current and Loop Current eddy frontal positions in the Gulf of Mexico, the Princeton Regional Ocean Forecast System (PROFS) is tested to forecast 14 4-week periods Aug/25/99- Sep/20/00, during which a powerful eddy, Eddy Juggernaut (Eddy-J) separated from the Loop Current and propagated southwestward. To initialize each forecast, PROFS assimilates satellite sea surface height (SSH) anomaly and temperature (SST) by projecting them into subsurface density using a surface/subsurface correlation that is a function of the satellite SSH anomaly. The closest distances of the forecast fronts from seven fixed stations in the …

Oceanic Uptake And The Global Atmospheric Acetone Budget, Christa Marandino, Warren J. De Bruyn, Scott Miller, M. J. Prather, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this study, direct measurements of the air/ sea flux of acetone were made over the North Pacific Ocean. The results demonstrate that the net flux of acetone is into, rather than out of the oceans. The extrapolated global ocean uptake of 48 Tg yr(-1) requires a major revision of the atmospheric acetone budget. This result is consistent with a recent reevaluation of acetone photodissociation quantum yields.

Monsoon-Driven Biogeochemical Processes In The Arabian Sea, Jerry D. Wiggert, Raleigh Hood, Karl Banse, John Kindle

Faculty Publications

Although it is nominally a tropical locale, the semiannual wind reversals associated with the Monsoon system of the Arabian Sea result annually in two distinct periods of elevated biological activity. While in both cases monsoonal forcing drives surface layer nutrient enrichment that supports increased rates of primary productivity, fundamentally different entrainment mechanisms are operating in summer (Southwest) and winter (Northeast) Monsoons. Moreover, the intervening intermonsoon periods, during which the region relaxes toward oligotrophic conditions more typical of tropical environments, provide a stark contrast to the dynamic biogeochemical activity of the monsoons. The resulting spatial and temporal variability is great and …

Chemical Characterization Of Ambient Aerosol Collected During The Northeast Monsoon Season Over The Arabian Sea: Anions And Cations, Anne M. Johansen, Michael R. Hoffmann

All Faculty Scholarship for the College of the Sciences

Ambient aerosol samples were collected over the Arabian Sea during the month of March 1997, aboard the German R/V Sonne, as part of the German JGOFS project (Joint Global Ocean Flux Study). This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high volume collector samples were analyzed for anions and cations upon return to the laboratory. Anthropogenic pollutant concentrations were larger during the first part of the cruise, when air masses originated over the Indian subcontinent. Total NSS‐SO₄²⁻ concentrations amounted to 2.94 ± …

Sources And Cycling Of Carbonyl Sulfide In The Sargasso Sea, Gregory A. Cutter, Lynda S. Cutter, Katherine C. Filippino

OES Faculty Publications

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L^-1, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L^-1) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L^-1 h^-1, whereas dark production was 7.0 pmol L^-1 h^-1. Apparent quantum yields were 10^-5-10^-7 from 313-436 …

Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert

CCPO Publications

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm …

Modeled And Observed Empirical Orthogonal Functions Of Currents In The Yucatan Channel, Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, Wilton Sturges

CCPO Publications

Candela et al. [2003] have reported empirical orthogonal function (EOF) analyses based on 23-month current-meter and acoustic Doppler current profiler measurements in the Yucatan Channel. Those authors noted the difference between EOFs obtained from observations and their z-level models and EOFs calculated by Ezer et al. [2003] from the results of a terrain-following model. Here a new analysis is reported that explains this difference, and that also suggests the importance of shelf-edge meander mode of the core Loop Current in the channel. We show that the terrain-following model gives EOFs with characteristics similar to those observed when data from the …

Chemical Characterization Of Ambient Aerosol Collected During The Northeast Monsoon Season Over The Arabian Sea: Labile-Fe(Ii) And Other Trace Metals, Anne M. Johansen, Michael R. Hoffmann

All Faculty Scholarship for the College of the Sciences

Ambient aerosol samples were collected over the Arabian Sea during the month of March of 1997, aboard the German R/V Sonne, as part of the German Joint Global Ocean Flux Study (JGOFS) project. This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high‐volume collector samples were analyzed for ferrous iron immediately after collection, while trace metals, anions, and cations were determined upon return to the laboratory. The main crustal component was geochemically well represented by the average crustal composition and amounted to 5.94 ± 3.08 …

Near-Surface Currents In Desoto Canyon (1997–99): Comparison Of Current Meters, Satellite Observation, And Model Simulation, Dong-Ping Wang, Lie-Yauw Oey, Tal Ezer, Peter Hamilton

CCPO Publications

This study evaluates a data-assimilated model simulation of near-surface circulation in DeSoto Canyon (DSC), Gulf of Mexico, with emphasis on analyzing moored current-meter observations and comparing them with satellite data and model results. The study period is for two years from April 1997 to April 1999. The model results are from a high-resolution Gulf of Mexico model forced by analyzed wind and surface heat flux. Two types of data are used to deduce near-surface circulation: moored current meters at 13 locations in the DSC, and satellite sea level anomaly. The moored currents are mapped through multivariate objective analysis to produce …

Sea Level Slopes And Volume Fluxes Produced By Atmosphere Forcing In Chesapeake Bay, David Salas Monreal

OES Theses and Dissertations

Year long time series at eight stations in the Chesapeake Bay and inner shelf were used to determine the relative influence of wind, barometric pressure and thermosteric effects on subtidal sea level variability and slopes. Special emphasis was placed on the lower Chesapeake Bay, where inverse barometric effects accounted for up to 33% of the subtidal sea level variations and thermosteric effects accounted for less than 1 % of the variations. The greatest thermosteric influence was noted at the southernmost, saltier and shallower location (Chesapeake Bay Bridge Tunnel). Wind forcing accounted for most of this station's variability, making up more …

A Conceptual Model Relating The Quasi-Biennial Oscillation And The Troposheric Biennial Oscillation, Kok Foo Kwan

Student Works (2000-2009)

A survey of the zonal wind throughout the troposphere and the lower stratosphere near the equator is made for the 41-year period of 1958-98. A similar survey of the 500- hPa geopotential height, sea surface temperature (SST) and tropopause height is also made, except that the survey period for the tropopause height is shorter than 41 years due to unavailability of data. Other than the well-known Quasi-Biennial Oscillation (QBO) feature in the lower stratosphere and the Tropospheric Biennial Oscillation (TBO) feature exhibited by the SST, similar oscillation features are found throughout the whole troposphere by both surveys. Autocorrelation functions, Pearson …

Dark Production: A Significant Source Of Oceanic Cos, M. Von Hobe, Gregory A. Cutter, A. J. Kettle, M. O. Andreae

OES Faculty Publications

Carbonyl sulfide (COS) in air and dissolved in seawater was determined during a cruise in August 1999 in the Sargasso Sea in the northwest Atlantic Ocean. Dissolved concentrations at the sea surface displayed only a weak diel cycle with a mean of 8.6 ± 2.8 pmol dm⁻³ owing to low abundance of photochemical precursors and high temperatures causing rapid hydrolysis. Depth profiles measured over the oceanic mixed layer revealed significant vertical gradients of COS concentration with higher values at the surface, suggesting that the rate of photochemical production at the surface exceeds the rate of vertical mixing. The mean …

Can Long-Term Variability In The Gulf Stream Transport Be Inferred From Sea Level?, Tal Ezer

CCPO Publications

Recent studies by Sturges and collaborators suggest a simple, but powerful, technique to estimate climatic changes in the transport of the Gulf Stream from the difference between the oceanic sea level calculated with a simple wind-driven Rossby wave model and the observed coastal sea level. The hypothesis behind this technique is tested, using 40 years of data (1950 to 1989) obtained from a three-dimensional Atlantic Ocean model forced by observed surface data. The analysis shows that variations in sea level difference between the ocean and the coast are indeed coherent with variations of the Gulf Stream transport for periods shorter …

A Feasibility Study Of Dynamical Assimilation Of Tide Gauge Data In The Chesapeake Bay, Yvette H. Spitz

OES Theses and Dissertations

The feasibility of dynamical assimilation of surface elevation from tide gauges is investigated to estimate the bottom drag coefficient and surface stress as a first step in improving modeled tidal and wind-driven circulation in the Chesapeake Bay. A two-dimensional shallow water model and an adjoint variational method with a limited memory quasi-Newton optimization algorithm are used to achieve this goal.

Assimilation of tide gauge observations from ten permanent stations in the Bay and use of a two-dimensional model adequately estimate the bottom drag coefficient, wind stress and surface elevation at the Bay mouth. Subsequent use of these estimates in the …

Dynamics Of Dipoles In The Middle Atlantic Bight, Bruce L. Lipphardt Jr.

OES Theses and Dissertations

Beginning with the observations made by the Warm-Core Rings program in the early 1980's, several Gulf Stream warm-core rings (WCR's) in the Middle Atlantic Bight (MAB) have been observed with one or more cyclones around their periphery. These ring systems are observed in the slope water between the Gulf Stream's western boundary and the shelf break. Observations of ring systems have motivated a reanalysis of existing satellite surface temperature imagery, which revealed that multipole structure is common for both warm and cold core rings. This suggests that rings are better characterized as one part of multipole systems rather than as …

Fisheries And Oceanography Off Galicia, Nw Spain: Mesoscale Spatial And Temporal Changes In Physical Processes And Resultant Patterns Of Biological Productivity, K. R. Tenore, M. Alonsonval, L. P. Atkinson, J. M. Cabanas, R. M. Cal, H. J. Campos, F. Castillejo, E. J, Chesney, N. Gonzalez, R. B. Hanson, C. R. Mcclain, A. Miranda, M. R. Roman, J. Sanchez, G. Santiago, L. Valdes, M. Varela, J. Yoder

CCPO Publications

The Galician shelf off NW Spain (43N degrees 9W degrees) exhibits mesoscale spatial and temporal changes in biological productivity associated with upwelling. Spatial heterogeneity results from local geomorphic and land-sea interactions superimposed on the large scale atmospheric processes that produce upwelling. Wind-induced upwelling events, commonly of short (i.e., week) duration, are more common in the summer than in the winter. A Series of cruises, including some time series sampling, and satellite imagery analysis showed that surface upwelling was more common and persistent on the northern coast compared with the western coast off the coastal embayments, the Rias Bajas. Nearshore off …

Heat Storage And Transport Processes In The Tropical Atlantic Ocean, Andras Kapolnai

OES Theses and Dissertations

Heat storage and transport processes of the tropical Atlantic play an important role in the climate of three continents. The exploration of how the warm water mass maintenance in the equatorial basin depends on various external factors is therefore an important task. This study examines the annual cycle of the warm water mass formation and its transport in the equatorial Atlantic through the interaction of the atmospheric and oceanic boundary layers. Key features of the model are the sea level wind field, equatorial upwelling rate and escape transport of the formed warm water out of the equatorial basin.

The model …

A Comparison Of Gulf Stream Sea Surface Height Fields Derived From Geosat Altimeter Data And Those Derived From Sea Surface Temperature Data, Tal Ezer, George L. Mellor, Dong-Shan Ko, Ziv Sirkes

CCPO Publications

Two types of satellite data, Geosat altimeter data and sea surface temperature data (SST), are compared and evaluated for their usefulness in assimilation into a numerical model of the Gulf Stream region. Synoptic sea surface height (SSH) fields are derived from the SST data in the following way: first three-dimensional temperature and salinity analysis fields are obtained through the Optimum Thermal Interpolation System (OTIS), and then SSH fields are calculated using a primitive equation, free-surface, numerical model running in a diagnostic mode. The aforementioned SSH fields are compared with SSH fields obtained from the Geosat altimeter data. Use of Geosat …

Hydrogen Sulfide And Radon In And Over The Western North Atlantic Ocean, T. W. Andreae, Gregory A. Cutter, N. Hussain, J. Radford-Knoery, M. O. Andreae

OES Faculty Publications

Atmospheric measurements of radon and hydrogen sulfide, and seawater measurements of total sulfide, free sulfide, and carbonyl sulfide, were made on a cruise in the western North Atlantic Ocean (October 24 to November 9, 1989). Measured values for ²²²Rn ranged from 3 to 70 pCi m⁻³, those for atmospheric hydrogen sulfide from 1 to 85 parts per trillion, and those for dissolved total and free sulfide in seawater from 33 to 930 pmol L⁻¹ and 0 to 73 pmol L⁻¹, respectively. A positive correlation between ²²²Rn and atmospheric H₂S was observed. …

Observations Of A Cyclonic Ring: Gulf Stream Coalescence Event Over The Blake Plateau, Julie Mcclean-Padman, Larry P. Atkinson

CCPO Publications

Hydrographic data collected in September 1980 over the Blake Plateau were analyzed using a combination of empirical search and inverse techniques. Five sections, extending from the continental shelf break eastward across the Blake Plateau, were positioned at approximately 1-degrees intervals between 28-degrees and 32-degrees-N. The empirical search procedure was applied to four closed regions (boxes), constructed from adjacent sections, where each region was assumed to consist of two conservative layers. Five geostrophic velocity sections were obtained using the average optimum reference level for the four boxes. The inverse technique provided barotropic correction velocities that caused all layers to conserve mass. …

Mesoscale Hydrographic Variability In The Vicinity Of Points Conception And Arguello During April May 1983: The Opus 1983 Experiment, Larry P. Atkinson, Kenneth H. Brink, Russ E. Davis, Burton H. Jones, Theresa Paluszkiewicz, David W. Stuart

CCPO Publications

In April and May 1983, interdisciplinary oceanographic observations were made of upwelling events in the Point Conception area off southern California. The principal objective was to observe the structure and time dependence of the upwelling system. To accomplish this, two ships, two aircraft, moorings, drogues, and satellite imagery were all included in the observational effort. During the intensive measurement period three main upwelling events and two intervening relaxation or downwelling intervals were sampled during what was a period of overall longer-term sea surface warming. Surface temperatures during upwelling were as low as 10.5°C in the upwelling center between Point Arguello …

Storm Surge Predictions At Sewell's Point With Local Wind, Pressure, And Previous Surge As Surge Predictors In Chesapeake Bay, Joy Elaine Moses

OES Theses and Dissertations

The statistical model used to predict storm surge. which is defined as the difference between observed water level and predicted astronomical tide. at Sewell's Point. Virginia. for the last ten years relies on forecast surface air pressures interpolated over a large portion of the Atlantic Ocean. A variation on this method is developed which adds previous station surge and local wind and pressure terms with time leads up to 18 hours to the Pore prediction for surge. and develops surge prediction equations for three substations eight to 65 miles (13 to 105 km) from Sewell's Point. The Sewell's Point surge …

The Apparent Dissociation Constants Of Carbonic Acid In Low Salinity Waters, Ching-Hui Hsu

OES Theses and Dissertations

The first and second apparent dissociation constants of carbonic acid in artificial seawater and diluted artificial seawater, K₁ ' and K₂ 1 were determined at selected combinations of temperatures and salinities between 2 to 30° C and 0 to 35 o/oo with special attentions to waters with salinities below 20 o/oo at atmospheric pressure by measuring K₁ ' and the product of K₁ ' and K₂.

The results can be expressed as functions of temperature and salinity by the following equations, pK₁ '=3360.206T^-1 +0. 033331 T-14.8303-0.09633x (Cl^1/2) pK₂ '=14911.671 …

Effects Of El Nino On Local Hydrography And Growth Of The Giant Kelp, Macrocystis Pyrifera, At Santa Catalina Island, California, Richard C. Zimmerman, Deborah L. Robertson

OES Faculty Publications

Deepened isotherms associated with El Niño resulted in severe nutrient limitation and very low kelp productivity during the last half of 1983. Frond growth rates were so low that terminal blades formed before reaching the surface, eliminating the canopy. Frond initiation rates were also extremely low, resulting in significant reductions in mean plant size. Plants growing above 10m were more severely affected than plants at 20m. Nutrient pulses associated with internal waves are thus critical for survival of Macrocystis pyrifera in nutritionally marginal habitats in Southern California.