Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / Microfiche copy available in Archives and Science. / Vita. / Bibliography : leaves 122-129. / by Dean Howard Roemmich. / Ph.D.

Recently, there has been an increase in marine mammal mortalities, most commonly Atlantic bottlenose dolphins, Tursiops truncatus, which is an alarming indication of the health status of the marine ecosystem. Studies have demonstrated that some free-ranging dolphins exhibit a suppressed immune system possibly because of exposure to contaminants or infectious microorganisms. However, this research has been limited due to a lack of commercially available marine-specific antibodies. Therefore, the first chapter of this thesis aims to identify cross-reactive terrestrial-specific antibodies that could be used to phenotype and compare the immune cell populations of dolphins under human care and free-ranging dolphins. The second chapter aims to utilize terrestrial-specific growth factors and dendritic cell (DC) surface markers to generate, characterize, and compare ex vivo DCs from peripheral blood mononuclear cells (PBMCs) of dolphins under human care and free-ranging dolphins. In summary, I have identified differences within the PBMCs and ex vivo generated DCs of dolphins under human care and free-ranging dolphins that could potentially shed light on the impact of environmental contaminants and infectious microorganisms on immune cells which could lead to increased morbidity and mortality. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 81-83. / by Affonso da Silveira Mascarenhas, Jr. / M.S.

Thesis (Ph. D.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 165-174). / The variability in the DWBC, its connection to the forcing in the northern North Atlantic and interaction with the Gulf Stream were explored from a combination of remote sensing and in-situ measurements in the western North Atlantic. Using satellite altimetry and Sea Surface Temperature (SST) we found evidence of the relation between changes in the Gulf Stream path and the variability in the temperature and velocity fields in the Slope Water. This relation was such that southward shifts of the main axis of the Gulf Stream were preceded by cold temperature anomalies and intensification of the southwestward flow. The analysis of 5.5 years of moored CTD and horizontal velocity data in the DWBC at 69 0W recorded during the period 2002-2008, showed that the variability along the DWBC is linked to changes in the dense water formation regions. The evolution of potential vorticity (PV) at the mooring site, characterized by a transition from deep to upper Labrador Sea Water (LSW), was similar to that observed in the Labrador Sea 6 to 9 years earlier, and imply spreading rates for the LSW that varied over time from 1.5 to 2.5cm/s. The time dependence of the spreading rates was in good agreement with changes in the strength of the DWBC at the mooring site. The evolution of the DWBC transport was explored in more detail from a 5- element moored array, also at 69'W. The results, for the period of 2004-2008, were consistent with the single mooring analysis. The variability measured from the array showed that upper, intermediate and deep water mass layers expand and contract at each other's expense, leading to alternating positive and negative PV anomalies at the upper-LSW, deep-LSW and Overflow Water (OW). Larger DWBC transports were associated with enhanced presence of recently ventilated upper-LSW and OW, rather than deep-LSW. The relative contribution of the different water masses to the observed circulation was investigated by inverting individual PV anomalies isolated from the observations. We found that changes in the depth-integrated circulation were mostly driven by changes in the OW. / by Beatriz Peña-Molino. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 221-225. / by Ping-Tung Peter Shaw. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography: leaves 255-261. / by Neal Robert Pettigrew. / Ph.D.

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The investigation of the role of basin-scale forcing on the circulation of the Faroe-Shetland Channel (FSC) is important to further understanding of the inter-annual variability of the Atlantic water (AW) fluxes in this region. The FSC plays a key role in the transfer of warm and saline AW towards the Nordic Seas that is an integral part of the Atlantic Meridional Overturning Circulation which is projected to decline over the twenty-first century and might reduce the oceanic heat and salt transports towards the Arctic. So far little attention has been paid to the mechanisms driving the AW fluxes in the FSC, reliable estimates of AW temperature and salt transports time series are lacking. This study presents a new time series of the AW fluxes based on the combination of hydrography and altimetry data. The mechanisms involved in driving the variability of AW fluxes are considered based on observational data and the output from a high-resolution ocean model (VIKING20). The hydrographic observations from 1993 to 2015 show an increase in temperature and salinity of AW. However, there is no evidence of trends in AW volume, temperature or salt transports during the observed period. This analysis confirms that the amount of heat and salt transported through the FSC is dominated by the volume transport. Moreover, this study identifies a bias in the standard deviation of the geostrophic velocity at a depth associated with referencing the geostrophic calculations to the sea surface geostrophic velocity from satellite altimetry. This finding does not strongly influence the AW volume transports in the AW layer, however, it has important implications for estimates of the geostrophic volume transport at depth. This study shows that the Ekman driven up/downwelling and the differential Ekman pumping mechanisms driven by the local wind forcing may influence sea surface height (SSH) and the displacement of isopycnals in the channel, leading to AW volume transport variabilit However, due to the large associated error bars on the surface and subsurface parameters, there is no clear evidence that these mechanisms are significantly responsible for the AW volume transport variability in the FSC. Lagrangian trajectories show evidence of two pathways from the North Atlantic to the FSC that may explain AW variability in the FSC: one pathway involves the flow of warm and saline waters from the Rockall Trough that corresponds to high temperatures and low AW volume transport in the channel, and the other pathway involves the flow of relatively cooler and less saline waters from the Iceland Basin that is linked to low temperatures and stronger volume transport in the FSC. Moreover, we show that the first (second) pathway is associated with the negative (positive) phases of the North Atlantic Oscillation (NAO) and the ocean gyre contraction (expansion). The changes of the NAO index phases explain 26 % of the AW volume transport variance in the FSC. Another important mechanism that leads to stronger (weaker) AW volume transport is stronger (weaker) pressure gradient across the Greenland-Scotland Ridge, reflected by the SSH changes. This mechanism explains 29 % of AW volume transport variance in the FSC.

Previous correlations have been established between the El Nino Southern Oscillation (ENSO) and both the tropical north Atlantic sea-surface temperatures (SSTs) and precipitation anomalies in the southeastern and mid-Atlantic states. Both bivariate and partial correlations are used over a five and six-month lag to assess the relevance the tropical Atlantic SSTs have in eastern United States precipitation patterns. Significant correlations between Pacific SSTs and precipitation were found during winter months which agree with previous literature. The relationship with the Atlantic SSTs was less robust, as some significant values were established over three seasons, excluding winter. Only the spring season showed a partial explanation of the Atlantic SST's role in the precipitation's response to Pacific SSTs. These relationships did not occur during the times when significant correlations were made between Pacific SSTs and precipitation. / Department of Geography