Approved for public release; distribution is unlimited / Naval operations are highly dependent upon environmental conditions that can either adversely affect successful completion or hinder the safety of personnel. Each warfare community has defined environmental thresholds and operating limits that restrict the execution of any intended maneuver. As the warfare environment continues to shift from open ocean to the littoral, environmental prediction and modeling efforts of the shallow water surroundings need to be developed in order to support these operations. A hydrodynamic model, Water Quality Management and Analysis Package (WQMAP), has been developed by Applied Sciences Associates, Inc. that is designed specifically to provide accurate littoral environmental prediction. WQMAP is one of several hydrodynamic models used operationally by the Naval Oceanographic Office (NAVOCEANO) to predict currents and water elevations in littoral regions. Implementations of shallow water hydrodynamic models in foreign waters are usually data-starved for model forcing and validation. In a series of studies, NAVOCEANO intends to model various bays within the continental United States, where sufficient data exists, to study the sensitivity of lack of data on model results. This study will utilize WQMAP to design a hydrodynamic model in San Diego Bay to predict currents in order to investigate the impact of grid resolution on model results, and to provide proper current predictions for Fleet training and operations. / Lieutenant, United States Navy

Approved for public release; distribution is unlimited / The use of the HF radar to measure and map surface currents has proliferated along the coastlines of many countries for purposes of Search and Rescue, Oil Spill Management, Oceanographic and Fishery Science studies. In the US Navy, these surface current maps are being evaluated for operational use in real-time data assimilating coastal circulation models, and direct monitoring tools in environmentally sensitive operating areas. The SeaSonde HF radar, a DF system, was considered in this study. It uses the MUSIC algorithm to recover bearings from the Doppler backscatter spectrum of the sea surface. By varying the radial and antenna patterns, the simulated backscatter spectra were passed through the SeaSonde software suite for radial pattern recovery. This unprecedented approach directly evaluated SeaSondeâ s MUSIC, and the associated uncertainties were examined against the simulated inputs of (1) fixed amplitude and phase deviations from the ideal antenna pattern, (2) measured antenna patterns and (3) decreasing SNR. It was found that using the measured antenna pattern to recover radials yielded least uncertainty, but a definitive prediction of MUSICâ s radial-recovery capability in relation to the patternâ s complex amplitude and phase structure remained illusive. The results highlighted the need to calibrate the militaryâ s DF-systems for accurate azimuth recovery. / Outstanding Thesis

TRACT (maximum 200 words) The Northern Oscillation Index (NOI), an atmospheric climate index relating climate variations in the tropical Pacific and Northeast Pacific was used to selectively average output from the Parallel Ocean Climate Model (POCM 4C) for 1979-1998. Composites, or smart climatologies, were made representing El Nino (EN) and La Nina (LN) conditions, as well as a long term mean (LTM) average or traditional climatology, for November to March. Conditions in the California Current System (CCS) in the smart climatologies were consistent with large scale features noted in previously published studies of EN and LN. Overall, the patterns of anomalies (POCM 4C Smart Climatology minus POCM 4C Traditional Climatology) in salinity, temperature, and currents were opposite in sign and magnitude between the EN and LN composites. This was expected for opposite phases of the same climate variation, and many of the model's EN/LN differences were found to be statistically significant. Therefore, POCM 4C smart climatologies provide better estimates of ocean state and circulation patterns than traditional climatology. Such smart climatologies offer improved environmental information to Naval operational and strategic planners. They are also useful for studying climate variations, and in improving boundary and initial conditions for ocean and atmosphere models.

Video imaging data generated from the Naval Postgraduate School Imaging System (NAPSIS) during November 2004 to June 2006 was analyzed to determine the location of rip channels and track their morphology. During the study period, the rip fields constantly changed in shape, size, and location. Rip channels were found to have a mean migration southward at a rate of 0.16 meters per day with a standard deviation of 7.6 meters per day and maximum rates varying between approximately 30 meters per day north and 30 meters per day south. The migration exhibited a strong seasonal variation with southerly shifts in the fall and winter months, northerly shifts in the late winter and early spring months, and no significant shift in the late spring and summer months. Directional wave spectra measured every hour at the offshore NOAA buoy were refracted to the 10 meter depth contour at Marina and Sand City and compared with measured spectra at these locations. The significant wave heights at both locations exhibited a correlation of 0.94. Mean wave directions for Marina and Sand City were found to have correlations of 0.83 and 0.34, respectively. These refracted data were then used to calculate sediment transport rates at Stillwell Hall, Fort Ord. Rip channel migration and calculated sediment transport rates were correlated at 0.8, qualitatively confirming the hypothesis that the migration rate of rip channels is a function of modeled alongshore sediment transport. The sometimes rapid migration of these large scale morphological features is critical to the successful planning and execution of U.S. Navy and Marine Corps beach assaults and the operation of mine warfare. Because amphibious and special forces operate mainly in shallow areas, the modeling of rip current direction and magnitude contributes greatly to effective mission organization and accomplishment. In addition to causing mines to drift, rip currents transport sediment that can cause the underlying morphology to change, possibly covering bottom mines and creating a potential hazard for military forces operating in the area. Being able to predict where mines may be drifting and how much sediment has concealed them is a necessity in securing a littoral battlespace.

The shallow waters west of Scotland feature strong variability in water properties on a variety of temporal scales. While the region is known to be subject to both coastal and oceanic influences, the causes of variability are poorly understood. The limited characterisation of changes in coastal waters impacts our ability to explain the behaviour of coastal ecosystems, and predict their resilience to future climate scenarios. This thesis uses historical data in conjunction with recent cruises and a coastal mooring to investigate the causes of variability in the waters west of Scotland. Two new inter-annual salinity time series on the European shelf are developed. The spatial variability in salinity in shallow waters is greatest during winter and increases by a factor of four between the shelf edge and the coastline. At the shelf edge, new observations of the along-slope current suggest that it is stronger but less stable during winter, leading to a greater availability of oceanic water on the outer Malin Shelf. However unlike other documented shelf regions, shelf edge processes do not directly influence Scottish coastal water properties. A baroclinic current originating in the Irish Sea is the main influence near the Scottish coast during quiescent periods, but wind forcing dominates shelf processes during most winters, with prevailing winds tending to drive oceanic water towards the coast. While salinity in the Sea of the Hebrides is moderately correlated to wind, coastal salinity is sensitive to both advective processes and freshwater runoff. On inter-annual time-scales, salinity on the Malin Shelf is higher when the North Atlantic Oscillation (NAO) is positive, whereas the northern Irish Sea is fresher during a positive NAO state. Salinity and flow pathways in Scottish coastal waters appear to be resilient both to changes in the Rockall Trough and a warming climate on decadal time-scales.

Approved for public release; distribution unlimited / In conjunction with the Huntington Beach Phase III Investigation, the diurnal variability in the wind and ocean currents from July 1 - October 12, 2001 over the San Pedro Shelf is investigated. Results suggest that the diurnal currents are driven by the diurnal winds but that the strength of the ocean response is modulated by the low frequency flow regime. The spectral peak of the near-surface currents is at the diurnal frequency, which is below the inertial frequency (1.107 cpd). The diurnal currents are surface-intensified, decaying with depth to a minimum at 10-13 m and increasing slightly in strength below that. The near-surface diurnal currents are in phase across the shelf, and are close to in phase with the winds over the shelf. The amplitude modulation of the diurnal energy of the ocean currents is correlated with the direction of the low frequency flow along the shelf;the energy is enhanced when the flow is equatorward, and weak when the flow is poleward. The amplitudes of the diurnal near-surface currents are also correlated with the diurnal winds. However, the low frequency currents and winds are not well correlated. / Lieutenant, United States Navy

A região costeira do Estado de São Paulo, entre Peruíbe (24o24\'30\'\'S, 46o54\'00\'\'W) e São Sebastião (23o50\'30\'\'S, 45o40\'00\'\'W) faz parte da Plataforma Continental Sudeste do Brasil (PCSE). A região possui grande importância econômica e social devido ao turismo, indústria de óleo e gás, e ao porto de Santos, o maior do país. Correntes sobre a plataforma continental interna (PCI) dessa região foram pouco estudadas antes do projeto ECOSAN. Durante o ECOSAN, dados de correntes foram obtidos por aproximadamente 10 meses (2005-2006), através de 4 fundeios: 3 localizados na PCI, próximo à isóbata de 20 m: em frente à Peruíbe (P20) (24o24\'30\'\'S, 46o54\'00\'\'W), em frente à Santos (S20) (24o03\'30\'\'S, 46o17\'30\'\'W), e próximo à ilha Montão de Trigo (M20) (23o50\'\'30\'S, 45o40\'\'00\'W); e 1 localizado na plataforma continental média (PCM), próximo à isóbata de 100 m, em frente à Santos (S100) (25o05\'00\'\'S, 45o42\'00\'\'W). Medições de ventos foram feitas durante o mesmo período através de 2 bóias meteorológicas, localizadas junto à P20 e M20, e na Lage de Santos (L30) (24o19\'48\'\'S, 46o11\'20,4\'\'W). Os dados foram analisados no domínio do tempo e da freqüência para estudar as características das correntes bem como a importância relativa das forçantes da circulação, principalmente: tensão de cisalhamento do vento, gradientes de pressão baroclínicos e troca de momentum entre a Corrente do Brasil (CB) e as águas mais internas da plataforma continental. Resultados mostraram que as componentes de corrente paralelas à topografia foram as mais energéticas, sendo aparentemente geostróficas. Correntes forçadas pelo vento na PCI foram observadas em P20 durante o verão e em M20. Já em S20, o vento não foi capaz de suplantar os efeitos baroclínicos causados pela descarga fluvial do sistema estuarino de Santos. Em períodos de ventos fracos M20 é forçada por efeitos baroclínicos, aparentemente sofrendo também influência do sistema estuarino de Santos. Em P20 durante o inverno foi constatada a presença de forçantes baroclínicas, sendo estas atribuídas às águas provenientes do sul, com influência do Rio da Prata, as quais possivelmente influenciam também a dinâmica da PCM. Durante o período amostrado não foi verificado nenhuma inuência direta da Corrente do Brasil sobre a PCM, e tampouco sobre a PCI, demonstrando que essas regiões possuem dinâmica distinta da plataforma continental externa. A circulação na plataforma continental estudada não é homogênea, apresentando um sistema complexo de uxos e contra-uxos, havendo uma tendência das correntes sobre a PCM e a PCI apresentarem sentidos opostos. Há também tendência das correntes na PCI apresentarem sentido predominante para NE sobretudo entre Santos e São Sebastião, enquanto que na PCM a direção predominante é para SW. / The São Paulo State coastal region located between the cities of Peruíbe (242430S, 465400W) and São Sebastião (235030S, 454000W) is part of the SouthBrazil Bight. This region has great economic and social importance due to the tourism, oil and gas industries and the presence of the largest Brazilian port (Santos). Currents at the regions inner-shelf were poorly sampled before the eld work of the ECOSAN project. During ECOSAN, current meter data was obtained for nearly 10 months (2005-2006), from 4 moorings: 3 deployed in the inner-shelf, near the 20 m isobath: in front of Peruíbe (P20) (242430S, 465400W), in front of Santos (S20) (240330S, 461730W) and near Montão de Trigo Island (M20) (235030S, 454000W); and 1 deployed at the mid-shelf, near the 100 m isobath, in front of Santos (S100) (25 0500S, 45 4200W). Wind time series were measured at the same period, at the two inner shelf moorings, P20 and M20, by a surface met-buoy, and at the Lage de Santos (L30) (241948S, 46 1120,4W). Current and wind data were analyzed in time and frequency domains for describing currents characteristics and comparing the relative importance of the forcing mechanisms for the inner-shelf circulation, mainly: wind-stress, baroclinic pressure gradients and Brazil Current momentum exchanges. Results showed that alongshelf current components were the most energetic and nearly geostrophic. Wind driven currents on the inner-shelf were observed on P20 during summer time and on M20, however on S20 the wind wasnt capable of overcoming baroclinic eects caused by river discharge from the Santos estuarine system. Over weak wind periods M20 was forced by baroclinic eects, apparently also inuenced by Santos estuarine system. Baroclinic forcing was observed on P20 during winter time, being atributed to waters from the south, under the inuence of the Plata River, possibly inuencing the mid-shelf as well. During the whole period there was no presence of Brazil Current eddies or meanders, showing that neither inner-shelf nor mid-shelf are inuenced by the outer-shelf dynamics. The continental shelf circulation is not homogeneous, with a complex pattern of uxes and counter-uxes, where currents have tendency to ow on opposite directions between mid and inner-shelf. There is also a tendency for currents on the inner-shelf to ow towards NE, speccialy between Santos and São Sebastião, and towards SW on the mid-shelf.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2017. / The purpose of the present study was to apply data collected monthly over a 6-year period along the almost 200 km long St. Helena Bay Monitoring Line in the Southern Benguela upwelling system to investigate co-variation between an upwelling index calculated from nearby wind records and physical and chemical properties along the transect. The extent to which the well-documented seasonal upwelling cycles is manifested at the surface along an inshore-offshore variation was investigated in the context of implications for the validity of remote sensing as a monitoring tool in this ocean area and to improve understanding of the physical drivers of biological processes in St. Helena Bay. This study shows that surface temperature and nutrient concentrations exhibit very poor seasonality and weak correlation with the upwelling index. This is, despite clear evidence for spatial inshore-offshore gradients in temperature, nutrients, and chlorophyll-a, consistent with an upwelling regime. The upper ocean temperature gradient shows a much better correspondence to the upwelling index but at the same time demonstrates that surface heating, and not vertical mixing related to upwelling, controls the upper ocean temperature gradient. In this study linear lagged correlations were also examined and discussed to gain insight into the effect upwelling has on the surface waters in St. Helena Bay with the view of determining the following: (1) Does upwelling lead to an increase or decrease of the water properties? (2) What is the characteristic lag between an upwelling event and its effect on these water properties? (3) Is the effect and/or lag different for the different seasons? and (4) Is the effect and/or lag different for stations inside the bay and those outside the bay?. A combination of surface turbulent cooling through upwelling occurred after a lag of 8 to 10 days in winter and early summer, but less than half in late summer, similar to results obtained with salinity. However, the rest of the salinity results fit in poorly with the temperature results. The only significant correlation obtained with the inshore stations during late summer is the inexplicable positive correlation at a lag of 7 days. For all three seasons virtually none of the oxygen results fit the expected pattern. All three nutrients showed a more positive correlation coefficient and significance than the negative ones. Significant negative correlations occurred mainly during late summer at lags of 7 to 9 days caused by planktonic depletion of nutrients. Also, in this season, significant positive correlations between south-north wind and nutrients only occurred at short lags. This observation supports the earlier temperature-based conclusion that the influence of upwelling develops most rapidly at this time of the year. A rapid increase in chlorophyll-a levels followed by nutrient enrichment of the surface layers are evident. iii The results suggest that remote sensing techniques would be inadequate tools to monitor upwelling events in the Southern Benguela. Secondly, the incidence of phytoplankton blooms is more likely triggered by stratified conditions associated with surface heating than relaxation of upwelling winds. Finally, these results also emphasise the importance of validating lagged outputs against real-time measurements in supporting a simpler hydrological model in narrowing down these significant uncertainties.

No description available.

This dissertation focuses on data analyzed from the Auroral Current and Electrodynamics Structure (ACES) sounding rocket mission. ACES consisted of two payloads launched nearly simultaneously in 2009 into a dynamic multiple-arc aurora. The mission was designed to observe the three-dimensional current system of an auroral arc system. To constrain the spatial-temporal ambiguity, the payloads were flown along nearly conjugate magnetic field footpoints, at various altitudes with small temporal separation. The high altitude payload took in situ measurements of the plasma parameters above the current closure region to measure the input signature into the lower ionosphere. The low-altitude payload took similar observations within the current closure region, where perpendicular cross-field currents can flow. A detailed description of the experimental configuration is presented, including operational details of the fields and plasma instruments flown on both payloads. The methods used to process data from the electrostatic particle detectors and the fluxgate magnetometer on both payloads are presented. Data from the all-sky imager details the auroral configuration at the time of launch. In situ data are presented detailing observations of the electric fields, magnetic fields, and the electron differential energy flux, as the payloads crossed nearly conjugate magnetic field lines. Field-aligned currents were calculated from magnetometer observations on the high altitude payload. These data were combined with electron flux data to show that the high altitude payload traversed regions of upward and downward field-aligned current. The low altitude payload observed signatures in the residual magnetic field components consistent with perpendicular closure current. Ionospheric collisionality is investigated to determine if it is a significant mechanism to explain observed differences in the low energy electron flux between the high altitude and low altitude payload. As a result of increased ionospheric collisionality, the ionospheric conductivity is investigated to interpret the in situ electric field observations. A model of auroral electrodynamics, that is under development, is discussed in the context of interpreting magnetometer data from the low altitude payload. The evolution of precipitating electron flux into the ionosphere and the effect this precipitation has on generating ionization is presented. The electron spectrum produced by the model were fit to the electron flux data observed by the low altitude payload. The height ionization profile, equilibrium electron density, and Hall and Pedersen conductivities were determined from the model electron spectrum incident to the ionosphere. It was shown that the low altitude payload flew just above the peak Hall and Pedersen conductivities, suggesting that the low altitude payload flew directly in the region where perpendicular closure currents were most significant.