ALBERT

Description: Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Progress In Oceanography 70 (2006): 91-112, doi:10.1016/j.pocean.2006.07.002.

Description: Gabriel T. Csanady turned 80 in December 2005 and we celebrate it with this special Progress in Oceanography issue. It comprises 20 papers covering some of the many areas that Gabe contributed significantly throughout his professional career. In this introductory paper we briefly review Gabe’s career as an engineer, meteorologist and oceanographer, and highlight some of his major contributions to oceanography, both as a scientist as well as an educator. But we also use this opportunity to remember and thank Gabe, and his wife Joyce, for being such good friends and mentors to several generations of oceanographers. The authors of the collection of papers in this volume deserve special thanks for their efforts. We also are pleased to acknowledge the support of Progress in Oceanography’s editor, Detlef Quadfasel, and the many anonymous reviewers who generously contributed their time and expertise.

Description: Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution December 1980

Description: Data from the COBOLT experiment, which investigated the first 12 km off Long Island's south shore, are analyzed and discussed. Moored current meter records indicate that the nearshore flow field is strongly polarized in the alongshore direction and its fluctuations are well correlated with local meteorological forcing. Complex empirical orthogonal function analysis suggests that subtidal velocity fluctuations are barotropic in nature and are strongly influenced by bottom friction. Wind-related inertial currents were observed within the coastal boundary layer (CBL) under favorable meteorological and hydrographical conditions. The magnitude of these oscillations increases with distance from shore, and they display a very clear 180° phase difference between surface and bottom layers. Nearshore inertial oscillations of both velocity and salinity records appear to lead those further seaward, suggesting local generation and subsequent radiation away from the coast. The response of the coastal zone to impulsive wind forcing is discussed using simple slab and two-layer models, and the behavior of the nearshore current field examined. The major features of the observed inertial motions are in good qualitative agreement with model predictions. It is found that, in a homogeneous domain, the coastal boundary condition effectively prohibits inertial currents over the entire coastal zone. In the presence of stratification the offshore extent of this prohibition is greatly reduced and significant inertial currents may occur within one or two internal deformation radii of the coast. The "coastal effect", in the form of surface and interfacial waves which propagate away from the coast, modifies the "pure" inertial response as it would exist far from shore. The kinematics of this process is such that a 180° phase difference between currents in the two layers is characteristic of the entire coastal zone even before the internal wave has had time to traverse the CBL. It is also suggested that, for positions seaward of several internal deformation radii, interference between the surface and internal components of the coastal response will cause maximum inertial amplitudes to occur for t 〉 x/c2, where c2 is the phase speed of the internal disturbance. The hydrographic structure of the CBL is observed to undergo frequent homogenization. These events are related to both advective and mixing processes. Horizontal and vertical exchange coefficients are estimated from the data, and subsequently used in a diffusive model which accurately reproduces the observed mean density distribution in the nearshore zone. Dynamic balance calculations are performed which indicate that the subtidal cross-shore momentum balance is very nearly geostrophic. The calculations also suggest that the longshore balance may be reasonably represented by a steady, linear equation of motion which includes surface and bottom stresses. Evidence is presented which shows that variations in the longshore wind-stress component are primarily responsible for the energetic fluctuations in the sea surface slope along Long Island. Depth-averaged velocities characteristically show net offshore transport in the study area, and often display dramatic longshore current reversals with distance from shore. These observations are interpreted in terms of a steady circulation model which includes realistic nearshore topography. Model results suggest that longshore current reversals within the CBL may be limited to the eastern end of Long Island, and that this unusual flow pattern is a consequence of flow convergence related to the presence of Long Island Sound.

Description: This work was supported by the Department of Energy through contract no. DE-AC02-EVI0005 entitled Coastal-Shelf Transport and Diffusion.

Description: The Nantucket Shoals Flux Experiment (NSFE79) was conducted across the continental shelf and upper slope south of Nantucket from March, 1979 to April , 1980 to measure the flow of shelf water from the Georges Bank/Gulf of Maine region into the Middle Atlantic Bight. Conceived as a cooperative field experiment involving the Northeast Fisheries Center (NMFS), U.S. Geological Survey (Woods Hole), University of New Hampshire, and the Woods Hole Oceanographic Institution, the experiment contained two principal components, a moored array of current meter and bottom instrumentation deployed at six locations across the shelf and upper slope spanning a depth range from 46 m to 810 m, and a series of 27 hydrographic surveys made along or near the moored array line during the experiment. A basic description of the NSFE79 hydrographic data has been given in Part 1 by Wright (1983). A description of the moored array components and the basic moored array data sets is presented here in Part 2.

Description: The NEFC participation was supported by the NMFS Marine Resources Monitoring, Assessment, and Prediction (MARt-1AP) Program. The U.S. Bureau of Land Management (BLM) supported the USGS field and analysis component under t~emoranda of Understanding M550-MU6-79, M551-MU8- 24, M551-MU9-4, and M551-MU0-18. The WHO! and UNH field programs were supported by the National Science Foundation under Grants OCE 78-19513 and OCE 78-26229.

Description: Author Posting. © The Author(s), 2015. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 73 (2015): 93-122, doi:10.1357/002224015815848811.

Description: The Gulf of Maine, a semienclosed basin on the continental shelf of the northwest Atlantic Ocean, is fed by surface and deep water flows from outside the gulf: Scotian Shelf Water (SSW) from the Nova Scotian shelf that enters the gulf at the surface and slope water that enters at depth and along the bottom through the Northeast Channel. There are two distinct types of slope water, Labrador Slope Water (LSW) and Warm Slope Water (WSW); it is these deep water masses that are the major source of dissolved inorganic nutrients to the gulf. It has been known for some time that the volume inflow of slope waters of either type to the Gulf of Maine is variable, that it covaries with the magnitude of inflowing SSW, and that periods of greater inflows of SSW have become more frequent in recent years, accompanied by reduced slope water inflows. We present here analyses of a 10-year record of data collected by moored sensors in Jordan Basin in the interior Gulf of Maine, and in the Northeast Channel, along with recent and historical hydrographic and nutrient data that help reveal the nature of SSW and slope water inflows. We show that proportional inflows of nutrient-rich slope waters and nutrient-poor SSWs alternate episodically with one another on timescales of months to several years, creating a variable nutrient field on which the biological productivities of the Gulf of Maine and Georges Bank depend. Unlike decades past, more recent inflows of slope waters of either type do not appear to be correlated with the North Atlantic Oscillation (NAO), which had been shown earlier to influence the relative proportions of the two types of slope waters that enter the gulf, WSW and LSW. We suggest that of greater importance than the NAO in recent years are recent increases in freshwater fluxes to the Labrador Sea, which may intensify the volume transport of the inshore, continental shelf limb of the Labrador Current and its continuation as the Nova Scotia Current. The result is more frequent, episodic influxes of colder, fresher, less dense, and low-nutrient SSW into the Gulf of Maine and concomitant reductions in the inflow of deep, nutrient-rich slope waters. We also discuss evidence that modified Gulf Stream ring water may have penetrated to Jordan Basin in the summer of 2013.

Description: Fundingwas provided by grants fromNOAAand the University of Maine.DJMwas also supported by theWoods Hole Center for Oceans and Human Health through National Science Foundation grant OCE-1314642 and National Institute of Environmental Health Sciences grant 1P01ES021923-01.

Description: This dataset contains salinity and stable isotope measurements taken of water samples collected during an October 2016 research cruise in the Gulf of Maine aboard the NOAA ship Pisces. Water samples were collected at 44 different stations throughout the Gulf of Maine at various depths from the surface to the seafloor using a carousel sampler with 12 different Niskin bottles and attached to a SeaBIRD 911 CTD. Salinity was measured in situ using the SeaBird 911 CTD with auxiliary sensors. Water samples were collected from depth in Niskin bottles and transferred to triple rinsed Thermo Scientific Nalgene 4 Oz natural hdpe plastic wide mouth leakproof bottles. Parafilm was secured around the cap of each bottle to help prevent evaporation. Samples designated for δ18O(water) analyses were stored in containers in the wet lab of the boat. Samples designated for δ15N(NO3-) and δ18O(NO3-) analyses were immediately placed in a walk-in freezer set at − 8°C. Once back at port, samples were overnight shipped to the Stable Isotope Lab at Iowa State University. Frozen samples were shipped in coolers with additional ice added and, upon arrival, immediately placed back in a freezer. This dataset also contains two freshwater samples collected from the Kennebec River in November and December 2016. Samples were hand collected and stored in Thermo Scientific Nalgene 4 Oz natural hdpe plastic wide mouth leakproof bottles. Samples were shipped on dry ice to Iowa State University and processed in the same way as the other saltwater samples as detailed below. Once at Iowa State University, samples designated for δ18O(water) were stored in the temperature controlled laboratory and then analyzed using a Picarro L2130-I Isotopic Liquid Water Analyzer with attached autosampler. Three different isotopic reference standards, VSMOW, USGS 48, and USGS 47, were used. At least one reference standard sample was used per 5 samples. The average combined uncertainty (analytical and average correction factor) was ±0.20‰ (2σ). Samples designated for isotopic analyses (δ15N and δ18O) of dissolved NO3- were first unfrozen at Iowa State University and filtered using 0.2 μm pore filters (Sartorius Minisart high flow syringe sterile PES membrane). Subsequently, water samples were treated with sulfamic acid (ACS grade, 99.3-100.3%) to remove any NO2- following the procedures outlined in Granger and Sigman (2009; doi:10.1002/rcm.4307). Briefly, glassware was acid washed and baked at 500°C. 60 ml of sample were treated with 600 μL 0.4M sulfamic acid (made using 10% v/v HCl) to reduce the pH to between 1.6 and 1.8, which is necessary to reduce NO2- to N2 and therefore remove it from the sample. After the reaction was allowed to occur for at least 5 min, samples were neutralized by adding 2M NaOH to the sample to return the sample to a pH of 7 (±0.5). Approximately 310 μL of NaOH were added to each sample but the exact amount of NaOH varied by sample and was determined using a pH meter. Samples were then refrozen, put on dry ice and shipped overnight to the University of California Davis Stable Isotope Facility. Samples were analyzed for δ15N(NO3-) and δ18O(NO3-) using the bacterial denitrification assay method as outlined by Sigman et al., (2001; doi:10.1021/ac010088e) and Casciotti et al., (2002; doi:10.1021/ac020113w), respectively. Isotopes were measured using a Thermoscientific Delta V Plus isotope ratio mass spectrometer coupled to a ThermoFinnigan GasBench + PreCon trace gas concentration system. Seven different reference standards were used to correct samples and report values on the international scale, Air: USGS34 KNO3, USGS35 NaNO3, Acros KNO3, Fisher KNO3, Strem KNO3, New Acros KNO3, and IAEA-NO-3 KNO3 (not used on all samples). Average analytical uncertainty (2σ) was ±0.5‰ for δ15N(NO3-) and ±0.3‰ for δ18O(NO3-). In order to assess the extent to which nitrification is occurring in the Gulf of Maine, we used the following equation for Δ(15, 18), first proposed by Sigman et al., (2005; doi:10.1029/2005GB002458): Δ(15, 18) = (δ15N(NO3-) - δ15Nm)-(15ε/18ε)x(δ18O(NO3-)-δ18Om) δ15Nm and δ18Om are mean δ15N and δ18O of dissolved NO3- in deep source waters, respectively. In this case, we use average values for samples taken at and below 100 m, where δ15N(NO3-) and δ18O(NO3-) remain relatively constant with depth. 15ε/18ε is the ratio of isotope fractionation factors for nitrogen and oxygen, respectively, for assimilation, which is taken to be 1 here. The propagated ([a2+b2]1/2) uncertainty for Δ(15, 18), calculated using the uncertainty associated with δ15N(NO3-) and δ18O(NO3-), is ±0.6‰ (2σ).