Rivers are conduit that transport terrestrial matters to the ocean. Studying how the composition and transport mechanism of terrestrial matters influenced by tide, wave, wind and discharge is an important issue in the disparate of river-sea systems. The aim of this study is to understand the temporal and spatial variability of the grain size distribution of a river plume, using EOF (Empirical Orthogonal Function) to analyze the correlation between environmental processes and suspended sediments. We used CTD and LISST-100 to collect upper-colum profile data at Gaoping River mouth in five (R/V Ocean Research III) cruises from 2005 to 2009. We also deployed an instrumented tetrapods and a moored buoy at the inner Gaoping River mouth and the inner continental shelf off Gaoping River mouth for two days, respectively. In all the upper-column data, the volume concentration increased in surface column when the salinity decreased. The variability of volume concentration are dominant in grain sizes between 10-250 £gm. We used EOF to analyz the time series to investigate the correlations among the volume concentration of 5 grain-size groups (<3, 3-10, 10-63, 63-153, and 153-250 £gm), salinity, water temperature, and alongshore and across-shore winds. The first eigenmode explains about 50 % of the total correlations. This mode describes the dominant influence of the river runoff that affected all the grain-size classes within the plume. This mode suggests that the grain-sizes between 3-250 £gm are of terrestrial origin (low salinity, high water temperature) exported during the ebbing tide. The second eigenmode accounts for about 20 % of the total correlations. This mode describes the dominant influence of the wind. When under the upwelling-favorable across-shore wind, the upwelling brings low temperature and clay-sized suspended sediment from the submarine canyon to the surface. The results suggest that the size-classes greater than 3 £gm are terrestrial suspended sediment and transported by the river plume, the size-classes finer than 3 £gm are mostly from the submarine canyon by the upwelling-favorable winds.

The dynamics of water mass transport in the Taiwan Straits is complicated. The time variations of transport in the strait may be influenced by local wind, remote wind, the sea-level gradient between two ends of the strait and the intrusion of Kuroshio etc. This research was aiming for the regional wind effect and the transport variation of the strait. The main data set to be applied in this study is the QSCAT wind. The transport data were the results calculated in EASNFS model of Dr. Dong-Shan Ko (Naval Research Laboratory, Stennis Space Center USA). In order to validate the accuracy of the QSCAT wind, comparisons of QSCAT wind and that of four land weather stations near the Taiwan were conducted. The analysis showed that the variation of QSCAT wind, qualitively, was similar to that of land stations. However, the amplitude of QSCAT wind was larger. In general, the wind speed of QSCAT multiplied by a factor 0.6 would about be equal to the wind speed of land based weather station. The major methods apply to wind data were the Empirical Orthogonal Function(EOF) and correlation analyses. All the available QSCAT data near Taiwan were collected and were divided into remote wind (East China Sea, Yellow Sea and South China Sea) and local wind (Taiwan Strait). The EOF spatial patterns and time variation were then put together with the strait transport. The results of EOF analysis of QSCAT satellite observation derived wind showed that the regional wind field near Taiwan (100~450N¡A1050~1400E) were mainly dominated by monsoons (mode 1). There was a good correlation between the monsoon wind and transport variation in Taiwan Strait, with correlation coefficient (r) 0.73. The mode 2 typhoon signal showed week correlation with the transport variation of the strait. The reason is unknown which requires further exploration. In the winter northeastern monsoon season, the Yellow Sea, East China Sea remote wind and Taiwan Strait local wind all showed good correlation with the transport of the strait. However, in southwest monsoon period, the South China Sea wind field and the Taiwan Strait local wind field showed poor correlation with the transport of the strait. Advanced analysis of south sea wind stress curl suggested that the wind stress curl may influence the South China Sea circulation and the Kuroshio intrusion, and then caused the transport variations of the Taiwan Strait.

Depuis le début des années 80, les progrès techniques permettent des estimations quantitatives des relations entre les structures internes de la Terre et sa forme. Des méthodes statistiques appliquées à un modèle tomographique de la Méditerranée permettent d’extraire 3 composantes qui capturent 70% de la variance des données. La première correspond à la réaction du manteau supérieur à la présence de lithosphère à 660 km, la seconde enregistre la réaction du manteau aux slabs subverticaux dans le manteau supérieur, la troisième capture les variations de vitesse sismiques du sommet des manteaux supérieur et inférieur. L’effet de ces 3 phénomènes sur le géoïde est modélisé en considérant : (i) Toutes les anomalies enregistrées par les données tomographiques constituent des sources d’anomalies. Leur effet est calculé en utilisant la gravito-visco-élasticité. Il semble que cette approche ne suffit pas à modéliser l’ensemble de la composante mantellique. (ii) les données tomographiques enregistrent les sources d’anomalies et tous les phénomènes de réajustement. En intégrant les anomalies de masses données par le modèle tomographique on obtient des structures détaillées qui surestiment la composante mantellique. (ii) Chaque composante isole des phénomènes du manteau liés à une source à laquelle est appliquée la théorie de la gravito-visco-élasticité. La composante mantellique obtenue est de longueur d'onde et amplitude compatibles avec le géoïde.La présence de calottes de lithosphère à la base de la zone de transition est susceptible d’être visible par le géoïde contrairement à la présence de slabs subverticaux dans le manteau supérieur / Progress made in seismic tomography and geodesy open the way to estimations of relations between the structures within the Earth and its shape. Applying statistical analysis to tomographic data of the mediterranean area, we extract 3 components that capture almost 70 % of the variance of the tomographic data : first one isolates the mantle reaction to lithospheric masses from the bottom of the transition zone, the second one is legated to subvertical lithsopheric slabs in the upper mantle, the third one corresponds to the tops of upper- and lower- mantle expression. Effect of these dynamics on the geoid has been modelized using considering that : (i) all the structures of the tomographic model are geoid anomaly sources, mantle component of the geoid is computed applying the gravito-visco-elasticity theory to take into account deflection of viscosity interfaces. This approach provides a smooth and low amplitude geoid mantle component. (ii) the tomographic model can register sources but also the all readjustment. Mantle component of the geoid is computed integrating anomalies of the model. It provides a detailled but too large with respect with the regional geoid mantle component. (iii) each component has capacity to isolate a phenomenon legated to a specific source of geoid anomalies. We applied gravito-visco-elastic theory specifically to it. That provides a mantle component detailled and that has a magnitude low enough with respect to the geoid.The presence of lithospheric caps on the bottom of the transition zone can be detected by the mantellic component of the geoid, but the geoid is not sensitive to subvertical slabs within the upper mantle

This study investigates the variations of flow field and water mass due to the influence of topographic effect in the Kaoping Submarine Canyon. The data used in this study are collected from five cruises of field observations using research vessel OR3. Instruments deployed include ship-board ADCP¡BCTD¡Btow-ADCP, moored ADCP and vertical arrays of temperature loggers. The collected data are analyzed through a variety of time series analysis technique, such as harmonic analysis¡Blow-pass filter¡BFFT and EOF analysis. The results show that (1) the flow in the Kao-ping Canyon was dominated by semi-diurnal tide. Harmonic analysis shows that both bottom layer and the shelf region are dominated by the M2 tide. The amplitude increases with canyon depth, and the major axis of tidal current align with canyon orientation. (2) Water mass are moving around by the oscillation tidal current along the canyon. During flood, surface water flow to southeast, while bottom flow is up canyon. During ebb, surface water goes to northwest, while bottom flow is down canyon. (3) The low-pass flows indicate a counter-clockwise rotation from surface down, which is explained due to bottom frictional effect. (4) EOF analysis of CTD profiles suggested that the first mode (semi-diurnal tide) can explain 88% of the variations.

Diversas atividades ligados ao gerenciamento de recursos hídricos necessitam da previsão de acumulados diários de chuva extremos. Entretanto, grande parte dos modelos utilizados operacionalmente apresentam uma tendência a subestimar os extremos de precipitação mesmo com apenas 24 horas de antecedência. Existem diversas razões para esse tipo de erro de previsão tais como, limitações nas parametrizações de convecção para modelos com resolução de dezenas de quilômetros e a não inclusão do efeito de aerossóis como núcleos de condensação de gotas de nuvens nos modelos de grande escala. Dentro desse contexto, este trabalho tem como objetivo analisar situações de eventos extremos de precipitação na região de Belém, Pará, onde o regime de precipitação é modulado, principalmente, pela brisa marítima, linhas de instabilidade, distúrbios ondulatório de leste, zona de convergência intertropical, alta da Bolívia e Vórtices Ciclônicos de Altos Níveis (VCAN). A abordagem será de identificação de perfis verticais cinemáticos e termodinâmicos típicos de eventos extremos de precipitação diária em Belém, Pará. Para esse fim, escolheu-se fazer uma análise de dados de radiossondagem e precipitação utilizando as Funções Ortogonais Empíricas (EOF - Empirical Orthogonal Functions combinadas e verificar como o Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) simula características básicas de chuva acumulada diária. A variância explicada das EOF calculadas a partir do conjunto de variáveis acumulado diário de precipitação (acpcp), temperatura (t), razão de mistura de vapor d\'água (rv), vento zonal (u) e vento meridional (v) e acpcp, u e v apresentaram valores de variância explicada baixos em relação as EOF calculadas a partir de acpcp e u somente. A terceira EOF (e3) foi a que melhor identificou os extremos chuvosos em relação a primeira e segunda. Observou-se padrões sinóticos favoráveis a convecção para os dias relativos à acumulados de chuva acima da média e menos favoráveis para os dias relativos à acumulados de chuva abaixo da média. Nos dias que apresentaram os maiores acumulados de chuva identificados por e3 verificou-se a presença da Alta da Bolívia e de um VCAN sobre o Oceano Atlântico influenciando a região de estudo. Observou-se um caso de uma linha de instabilidade que adentrou o continente associada a um jato de baixos níveis e outro caso de uma perturbação de latitudes médias, ambos os casos ocasionaram acumulados de chuva acima da média. O BRAMS apresentou máximos e mínimos de anomalias de acpcp coincidentes com os dados observados. Os dias relativos à acumulados de chuva acima da média apresentaram correntes ascendentes e descendentes mais intensas que os dias relativos à acumulados de chuva abaixo da média. Observou-se máximos de correntes ascendentes associados a formação de novas células convectivas. / Several activities related to water management need the forecasting of cumulative daily rainfall extreme. However, most of the models used operacionaly tend to underestimate the extreme rainfall even with 24 hours of advance. There are several reasons for this type of forecast error such as, limitations in convection parametrizations for models with resolution of tens of kilometers and not inclusion of the effect of aerosols as cloud condensation nuclei for cloud droplets in large-scale models. Withing this context, this study aims to analyze situations of extreme precipitation events in the region of Belém, Pará, where the rainfall regime is modulated mainly by sea breeze, squall lines, easterly wave disturbances, intertropical convergence zone, Bolivian high and cyclonic vortices of high levels (VCAN). The approach will be to identify kinematic and thermodynamics vertical profiles typical of extreme daily rainfall events in Belém, Pará. To this end, it was chosen to analyze sounding and rainfall data using the combined Empirical Orthogonal Functions (EOF) and verify how the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) simulates the basic features of daily accumulated rainfall. The explained variance of EOF calculated from the set of variables accumulated daily precipitation (acpcp), temperature (t), mixing ratio of water vapor (rv), zonal wind (u) e meridional wind (v) and acpcp, u and v showed low values of explained variance in relation to the EOF calculated from acpcp and u only. The third EOF (e3) was the best in the identification of extreme rainfall compared to first and second. Observed synoptic patterns are favorable to convection on days with accumulated rainfall above average and less favorable on days for accumulated rainfall below average. In the days that had the highest accumulated rainfall identified by e3, it was verified that the presence of the Bolivian high and a VCAN on the Atlantic Ocean influence the study region. A case of squall line that entered the continent associated with a low level jet and other case of disturbance of mid-latitudes, resulted in accumulated rainfall above average. The BRAMS presented maximum and minimum acpcp anomalies coincident with the observed data. The days on the accumulated rainfall above average showed more intense updrafts and downdrafts that the days on the accumulated rainfall below average. Observed maximum updrafts associated with the formation of new convective cells.

Auf der Grundlage von Sonnenphotometermessungen an drei Messstationen (AWIPEV/ Koldewey in Ny-Ålesund (78.923 °N, 11.923 °O) 1995–2008, 35. Nordpol Driftstation – NP-35 (84.3–85.5 °N, 41.7–56.6 °O) März/April 2008, Sodankylä (67.37 °N, 26.65 °O) 2004–2007) wird die Aerosolvariabilität in der europäischen Arktis und deren Ursachen untersucht. Der Schwerpunkt liegt dabei auf der Frage des Zusammenhanges zwischen den an den Stationen gemessenen Aerosolparametern (Aerosol optische Dicke, Angström Koeffizient, usw.) und dem Transport des Aerosols sowohl auf kurzen Zeitskalen (Tagen) als auch auf langen Zeitskalen (Monate, Jahre). Um diesen Zusammenhang herzustellen, werden für die kurzen Zeitskalen mit dem Trajektorienmodell PEP-Tracer 5-Tage Rückwärtstrajektorien in drei Starthöhen (850 hPa, 700 hPa, 500 hPa) für die Uhrzeiten 00, 06, 12 und 18 Uhr berechnet. Mit Hilfe der nicht-hierarchischen Clustermethode k-means werden die berechneten Rückwärtstrajektorien dann zu Gruppen zusammengefasst und bestimmten Quellgebieten und den gemessenen Aerosol optischen Dicken zugeordnet. Die Zuordnung von Aerosol optischer Dicke und Quellregion ergibt keinen eindeutigen Zusammenhang zwischen dem Transport verschmutzter Luftmassen aus Europa oder Russland bzw. Asien und erhöhter Aerosol optischer Dicke. Dennoch ist für einen konkreten Einzelfall (März 2008) ein direkter Zusammenhang von Aerosoltransport und hohen Aerosol optischen Dicken nachweisbar. In diesem Fall gelangte Waldbrandaerosol aus Südwestrussland in die Arktis und konnte sowohl auf der NP-35 als auch in Ny-Ålesund beobachtet werden. In einem weiteren Schritt wird mit Hilfe der EOF-Analyse untersucht, inwieweit großskalige atmosphärische Zirkulationsmuster für die Aerosolvariabilität in der europäischen Arktis verantwortlich sind. Ähnlich wie bei der Trajektorienanalyse ist auch die Verbindung der atmosphärischen Zirkulation zu den Photometermessungen an den Stationen in der Regel nur schwach ausgeprägt. Eine Ausnahme findet sich bei der Betrachtung des Jahresganges des Bodendruckes und der Aerosol optischen Dicke. Hohe Aerosol optische Dicken treten im Frühjahr zum einen dann auf, wenn durch das Islandtief und das sibirische Hochdruckgebiet Luftmassen aus Europa oder Russland/Asien in die Arktis gelangen, und zum anderen, wenn sich ein kräftiges Hochdruckgebiet über Grönland und weiten Teilen der Arktis befindet. Ebenso zeigt sich, dass der Übergang zwischen Frühjahr und Sommer zumindest teilweise bedingt ist durch denWechsel vom stabilen Polarhoch im Winter und Frühjahr zu einer stärker von Tiefdruckgebieten bestimmten arktischen Atmosphäre im Sommer. Die geringere Aerosolkonzentration im Sommer kann zum Teil mit einer Zunahme der nassen Deposition als Aerosolsenke begründet werden. Für Ny-Ålesund wird neben den Transportmustern auch die chemische Zusammensetzung des Aerosols mit Hilfe von Impaktormessungen an der Zeppelinstation auf dem Zeppelinberg (474m ü.NN) nahe Ny-Ålesund abgeleitet. Dabei ist die positive Korrelation der Aerosoloptischen Dicke mit der Konzentration von Sulfationen und Ruß sehr deutlich. Beide Stoffe gelangen zu einem Großteil durch anthropogene Emissionen in die Atmosphäre. Die damit nachweisbar anthropogen geprägte Zusammensetzung des arktischen Aerosols steht im Widerspruch zum nicht eindeutig herstellbaren Zusammenhang mit dem Transport des Aerosols aus Industrieregionen. Dies kann nur durch einen oder mehrere gleichzeitig stattfindende Transformationsprozesse (z. B. Nukleation von Schwefelsäurepartikeln) während des Transportes aus den Quellregionen (Europa, Russland) erklärt werden. / On the base of sun photometer measurements conducted at three different research stations (AWIPEV/Koldewey in Ny-Ålesund (78.923 °N, 11.923 °E) 1995-2008, 35. Northpole Drifting Station – NP-35 (84.3–85.5 °N, 41.7–56.6 °E) March/April 2008, Sodankylä (67.37 °N, 26.65 °E) 2004-2007) the aerosol variability in the european Arctic and their cause is analyzed. The main focus is to quantify the correlation between the measured aerosol parameters (aerosol optical depth, Angström coefficient, etc.) and the transport of aerosol from Europe and Russia on short timescales (days) as well as on long timescales (months, years). For the short timescales 5-day backward trajectories were calculated with the trajectory model PEP-Tracer at three different starting heights (850 hPa, 700 hPa, 500 hPa) four times the day (00:00, 06:00, 12:00, 18:00 UTC). Afterwards the non-hierarchical cluster method k-means is used to group the backward trajectories in differend aerosol source regions and allocate to the respective sun photometer measurements. This allocation of aerosol source region and sun photometer measurements does not show a correlation between polluted air mass of european or russian/asian origin and enhanced aerosol optical depth. However, in one case (March 2008) a clear influence of anthropogenic aerosol on the photometer measurements occurs. In March 2008, aerosol originating at forest fires in southeast Russia was transported into the Arctic and detected over NP-35 as well as Ny-Ålesund. Furthermore, the EOF method is used to verify if large-scale atmospheric circulation patterns determine the arctic aerosol variability. However, the connection to the sun photometer measurements is very weak except for seasonal variability. It is shown, that in spring-time due to the Iclandic low and the Siberian high, air masses from Europe and Russia as well as a strong high pressure system at Greenland and most parts of the Arctic cause higher aerosol optical depths in Ny-Ålesund. The transition from spring to summer aerosol concentration can at least partially be assigned to the replacement of the stable polar high in winter and spring by low pressure systems in summer. In addition to the transport pattern, chemical composition of the scattering aerosol in Ny-Ålesund was deduced from measurements by the Zeppelin station at the Zeppelin mountain (474m above sea level) near Ny-Ålesund. A clear positive correlation between sulfate and black carbon concentration was found. Both chemicals are mostly emitted through anthropogenic processes (e.g. combustion). The verifiable anthropogenic influence on the composition of arctic aerosols disagree with the missing linkage of transport from industrial regions to aerosol optical depth. It can only be explained by one or more transformation processes (e.g. nucleation of sulfuric acid) during the transport from the source regions (Europe, Russia) to the Arctic.

Diversas atividades ligados ao gerenciamento de recursos hídricos necessitam da previsão de acumulados diários de chuva extremos. Entretanto, grande parte dos modelos utilizados operacionalmente apresentam uma tendência a subestimar os extremos de precipitação mesmo com apenas 24 horas de antecedência. Existem diversas razões para esse tipo de erro de previsão tais como, limitações nas parametrizações de convecção para modelos com resolução de dezenas de quilômetros e a não inclusão do efeito de aerossóis como núcleos de condensação de gotas de nuvens nos modelos de grande escala. Dentro desse contexto, este trabalho tem como objetivo analisar situações de eventos extremos de precipitação na região de Belém, Pará, onde o regime de precipitação é modulado, principalmente, pela brisa marítima, linhas de instabilidade, distúrbios ondulatório de leste, zona de convergência intertropical, alta da Bolívia e Vórtices Ciclônicos de Altos Níveis (VCAN). A abordagem será de identificação de perfis verticais cinemáticos e termodinâmicos típicos de eventos extremos de precipitação diária em Belém, Pará. Para esse fim, escolheu-se fazer uma análise de dados de radiossondagem e precipitação utilizando as Funções Ortogonais Empíricas (EOF - Empirical Orthogonal Functions combinadas e verificar como o Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) simula características básicas de chuva acumulada diária. A variância explicada das EOF calculadas a partir do conjunto de variáveis acumulado diário de precipitação (acpcp), temperatura (t), razão de mistura de vapor d\'água (rv), vento zonal (u) e vento meridional (v) e acpcp, u e v apresentaram valores de variância explicada baixos em relação as EOF calculadas a partir de acpcp e u somente. A terceira EOF (e3) foi a que melhor identificou os extremos chuvosos em relação a primeira e segunda. Observou-se padrões sinóticos favoráveis a convecção para os dias relativos à acumulados de chuva acima da média e menos favoráveis para os dias relativos à acumulados de chuva abaixo da média. Nos dias que apresentaram os maiores acumulados de chuva identificados por e3 verificou-se a presença da Alta da Bolívia e de um VCAN sobre o Oceano Atlântico influenciando a região de estudo. Observou-se um caso de uma linha de instabilidade que adentrou o continente associada a um jato de baixos níveis e outro caso de uma perturbação de latitudes médias, ambos os casos ocasionaram acumulados de chuva acima da média. O BRAMS apresentou máximos e mínimos de anomalias de acpcp coincidentes com os dados observados. Os dias relativos à acumulados de chuva acima da média apresentaram correntes ascendentes e descendentes mais intensas que os dias relativos à acumulados de chuva abaixo da média. Observou-se máximos de correntes ascendentes associados a formação de novas células convectivas. / Several activities related to water management need the forecasting of cumulative daily rainfall extreme. However, most of the models used operacionaly tend to underestimate the extreme rainfall even with 24 hours of advance. There are several reasons for this type of forecast error such as, limitations in convection parametrizations for models with resolution of tens of kilometers and not inclusion of the effect of aerosols as cloud condensation nuclei for cloud droplets in large-scale models. Withing this context, this study aims to analyze situations of extreme precipitation events in the region of Belém, Pará, where the rainfall regime is modulated mainly by sea breeze, squall lines, easterly wave disturbances, intertropical convergence zone, Bolivian high and cyclonic vortices of high levels (VCAN). The approach will be to identify kinematic and thermodynamics vertical profiles typical of extreme daily rainfall events in Belém, Pará. To this end, it was chosen to analyze sounding and rainfall data using the combined Empirical Orthogonal Functions (EOF) and verify how the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) simulates the basic features of daily accumulated rainfall. The explained variance of EOF calculated from the set of variables accumulated daily precipitation (acpcp), temperature (t), mixing ratio of water vapor (rv), zonal wind (u) e meridional wind (v) and acpcp, u and v showed low values of explained variance in relation to the EOF calculated from acpcp and u only. The third EOF (e3) was the best in the identification of extreme rainfall compared to first and second. Observed synoptic patterns are favorable to convection on days with accumulated rainfall above average and less favorable on days for accumulated rainfall below average. In the days that had the highest accumulated rainfall identified by e3, it was verified that the presence of the Bolivian high and a VCAN on the Atlantic Ocean influence the study region. A case of squall line that entered the continent associated with a low level jet and other case of disturbance of mid-latitudes, resulted in accumulated rainfall above average. The BRAMS presented maximum and minimum acpcp anomalies coincident with the observed data. The days on the accumulated rainfall above average showed more intense updrafts and downdrafts that the days on the accumulated rainfall below average. Observed maximum updrafts associated with the formation of new convective cells.

The surface sediments off Southwestern Taiwan were collected during three different cruises in May 2009, November 2009, and March 2010, respectively. The concentrations of chlorophyll-a and phaeopigment, as well as benthic foraminifera species, were analyzed. The results show that the concentration of chlorophyll-a decreases with the distance from the shore, and the concentration of chlorophyll-a also decreases with increasing water depth. The concentration of phaeopigment seems to have no significant relationship with the water depth. The relationships between the concentrations of benthic foraminifera, chlorophyll-a, and phaeopigment are also not significant. Because samples were collected from different water depths on the continental shelf, slope and in a canyon, the oceangraphic setting therefore may be one of the main factors which influences the distribution pattern of benthic foraminifera. According to the EOF analysis, the water depth in sampling sites plays a very important role in terms of the distribution of living benthic foraminifera in this study. The distribution do not show significant difference between collecting seasons. Finally, the concentrations of the chlorophyll-a and phaeopigment decrease drastically in a downcore record. Quinqueloculina spp., an epifaunal foraminifer, shows a significant peak concentration in the depth of 5-6 cm downcore. Bioturbation probably was responsible for this change.

Sea surface temperature (SST) is an important oceanic parameter which can be accessed easily and vastly by satellite remote sensing. Recent hydrographic observations suggested that the water temperature near Dongsha Atoll were affected by internal waves of South China Sea (SCS). This study hypothesizes that the SST variations near Dongsha Atoll and continental shelf cab be observed by satellite data. To test the hypothesis, MODIS SST data during January 2005 to December 2009 were collected and analyzed using harmonic and EOF analyses. The results show that there can be a 1 ¢XC temperature drop, near Dongsha Atoll during the passage of internal waves, based on a longitudinal section cut for a typical SST image. The SST patterns in northern SCS are distributed lower in the east and higher in the west. The temperature showed an average of 0.5¢XC lower near Dongsha Atoll. Especially, the pattern of lower temperature near Dongsha is significant during neap tide in summer season. EOF analysis showed that the spatial distribution of SST aligned well with the bottom topography of the continental shelf. This result suggests that internal tide may be important to the vertical mixing in this region. The total variation of mode 1 in EOF accounted for 97.7% and is dominated by seasonal changes. For the long term and large area SST statistics, the internal wave induced variation is insignificant, as comparing the Dongsha region with shelf region and Kuroshio region.

The southern Chukchi and Bering Sea region regularly experiences powerful storms that bring high winds that cause positive and negative water level set-up (storm surges) events. Positive set-up events can cause coastal inundation, sometimes extending far inland for low-relief locations, and negative set-up events can be problematic for shallow-draft marine equipment, such as barges. A ten year record (2004-2014) of water level data is available from a NOAA tide gauging station situated at the Teck Alaska Inc. Red Dog Mine Port Facility located to the north of the Bering Strait on the southwest Chukchi Sea coast. In this thesis these data are used to develop a database of water level set-up (storm surge) events using a novel identification methodology; by adapting fundamental wind storm identification concepts used by Atkinson (2005) and applying them to a water level dataset. The surge event database is then analyzed to identify primary types of events, to derive seasonal patterns and frequencies of occurrence, and to determine likely atmospheric driving mechanisms. There were 44 surge events identified – 21 positive, 23 negative – that tended to occur during the months of November, December, and January; none were recorded in the months May through August. The event typing work suggested four distinct surge patterns. Analysis of weather drivers, performed through visual interpretation of the temporal shape/form of the events and via use of an Empirical Orthogonal Function (EOF) analysis, suggested favoured locations for storm systems – the far eastern Chukotka Peninsula for positive set up events (west of Red Dog Dock), and the Alaska Peninsula for negative set ups (south of Red Dog Dock). A storm system situated to the west of the port generates southwest winds that drive positive set-up events, and a storm situated to the south generates easterly winds that drive negative set-up events. The sea level pressure weather patterns for positive set-up surge events are much stronger and shorter lived than for negative set-up events. This work has established an improved understanding of seasonal storm surge for the region and offers a potential basis for the improved forecasting of both positive and negative set-up surge events in the future. / Graduate / 0725