Observations of Upwelling and Relaxation Events in the Northern Monterey Bay During August 2000

Observations of Upwelling and Relaxation Events in the Northern Monterey Bay During August 2000

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Publisher:

Published: 2005

Total Pages: 22

ISBN-13:

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The interplay between the Point Ano Nuevo upwelling center, an offshore anticyclonic mesoscale eddy, and the waters of the Monterey Bay was studied during a series of up- and downwelling favorable wind events during August 2000. The upwelling events were characterized by the appearance of cold, salty water at Point Ano Nuevo at the north end of the bay that subsequently spread southward across the mouth of the bay as the winds continued. During the downwelling/relaxation events, the surface current and temperature response was dominated by the onshore translation of the offshore eddy and by local surface heating in the bay itself. The circulation within the bay was cyclonic during both wind regimes but slightly more barotropic under poleward forcing. The ICON model, a nested, data assimilating, sigma coordinate model, was used to simulate The upwelling and relaxation events and calculate the subsurface current and density fields. The model reproduced the dominant current and temperature patterns outside the bay, including the southward flowing upwelling filament, the movement of the offshore eddy, the poleward flow off Point Sur, and the circulation within the bay. The model salinity fields at the surface and 100 m levels show that during upwelling, the bay was filled with higher-salinity water stemming from the Point Ano Nuevo upwelling center to the north. During downwelling, the source water for both the surface and 100 m levels was the colder, fresher California Current water offshore, which had advected southward well past Point Pinos during the previous upwelling event.


Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications

Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications

Author: SEON KI PARK

Publisher: Springer Science & Business Media

Published: 2009-02-08

Total Pages: 481

ISBN-13: 3540710566

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Data assimilation (DA) has been recognized as one of the core techniques for modern forecasting in various earth science disciplines including meteorology, oceanography, and hydrology. Since early 1990s DA has been an important s- sion topic in many academic meetings organized by leading societies such as the American Meteorological Society, American Geophysical Union, European G- physical Union, World Meteorological Organization, etc. nd Recently, the 2 Annual Meeting of the Asia Oceania Geosciences Society (AOGS), held in Singapore in June 2005, conducted a session on DA under the - tle of “Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications.” nd This rst DA session in the 2 AOGS was a great success with more than 30 papers presented and many great ideas exchanged among scientists from the three different disciplines. The scientists who participated in the meeting suggested making the DA session a biennial event. th Two years later, at the 4 AOGS Annual Meeting, Bangkok, Thailand, the DA session was of cially named “Sasaki Symposium on Data Assimilation for At- spheric, Oceanic and Hydrologic Applications,” to honor Prof. Yoshi K. Sasaki of the University of Oklahoma for his life-long contributions to DA in geosciences.


Observations and Modeling of the Shelf Circulation North of the Monterey Bay During August 2006

Observations and Modeling of the Shelf Circulation North of the Monterey Bay During August 2006

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Publisher:

Published: 2007

Total Pages: 105

ISBN-13:

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In August of 2006 the Adaptive Sampling and Prediction (ASAP) experiment was conducted near the northern Monterey Bay. Multiple assets including aircraft, autonomous vehicles, moorings, and numerical models were used to gain a better understanding of three-dimensional upwelling centers. Data were collected at two separate mooring locations using Acoustic Doppler Current Profilers (ADCPs) during the experiment. The focus of this thesis is to determine the effects of local wind forcing on the ocean circulation and provide a comparison between the data collected at the mooring locations and numerical predictions for the region. Upwelling and relaxation events are used as the basis for understanding the local wind forcing. Upwelling typically results in equatorward flow while relaxation events typically result in poleward flow. Several different types of analyses were used to determine the effects of the local wind forcing. A visual analysis was performed with stick vector plots and component plots of the rotated time series that compared the wind with the data from the water column. Two methods of cross correlation, component correlations and vector correlations, were exploited as well as a spectral analysis of the wind and ADCP data. Finally the coherence and phase between the wind and currents were examined. Based on the analysis it became evident that the currents were forced by both wind and non-local events such as eddies, meanders, and the large-scale alongshelf pressure gradient. Associated with the ASAP experiment, the Harvard Ocean Prediction System (HOPS), the Regional Ocean Modeling System (ROMS), and the Navy Coastal Ocean Model (NCOM) provided nowcasts that were compared with the mooring data to determine their accuracy and precision. Overall, in the beginning of August the models provided reasonable representations of the flow patterns at the mooring locations. The prediction error increased towards the end of August which was possibly related to data assimilation techniques and more non-local forcing at that time. The military application of this thesis is that accurate current prediction by ocean models will benefit amphibious operations, special warfare operations, and mine warfare in the littoral zone.


Deep-Sea Pycnogonids and Crustaceans of the Americas

Deep-Sea Pycnogonids and Crustaceans of the Americas

Author: Michel E. Hendrickx

Publisher: Springer Nature

Published: 2021-03-01

Total Pages: 709

ISBN-13: 3030584100

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Among the deep-sea marine invertebrates, pycnogonids and crustaceans represent ecologically important and most diverse groups of species. Yet both are still poorly understood. Sampling and exploring operations off the west and east coast of the Americas has significantly increased in the last two decades. However such operations are very costly and limited in number and frequency. In countries like Brazil, Canada, Chile, Colombia, Costa Rica, Mexico, Peru, the United States of America, and El Salvador a large effort has been made to explore the deep-sea resources and the rich diversity of the communities, resulting in a better understanding of the natural ecosystems on both coasts of America. Pycnogonids and many groups of deep-sea crustaceans have been intensively studied, from the smallest animals, like the mostly unknown benthic copepods to the largest decapods. This book presents new and updated information on various groups of deep-sea pycnogonids and crustaceans occurring off the American continent. Offering a valuable reference resource for scientists interested in this fascinating fauna, it includes review papers and new data on the deep-sea communities occurring off the USA, Mexico, El Salvador, Costa Rica, Colombia, Chile, Peru, Brazil and Argentina, as well as in larger areas in both the East Pacific and the West Atlantic. As such it covers most of the current deep-water research in Latin America.


Water Masses in the Monterey Bay During the Summer of 2000

Water Masses in the Monterey Bay During the Summer of 2000

Author:

Publisher:

Published: 2007

Total Pages: 21

ISBN-13:

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Water masses in Monterey Bay are determined from the CTD casts of the Monterey Ocean Observing System (MOOS) Upper-water-column Science Experiment (MUSE) August 2000 dataset. It is shown through cluster analysis that the MUSE 2000 CTD dataset contains 5 water masses. These five water masses are bay surface water (BSW), bay warm water (BWW), bay intermediate water (BIW), subarctic upper water (SUW), and North Pacific deep water (NPDW). The BWW is a new water mass that exists in one area and is attributed to the effects of solar heating. The volumes occupied by each of the water masses are obtained. The BIW water is the most dominant water mass and occupies 68.8% of the volume. The statistical means and standard deviations for each water parameter, including spiciness and oxygen concentration, are calculated during separate upwelling and relaxed periods. The water mass content and structure are analyzed and studied during upwelling and a relaxed period. During upwelling, along a CTD track off Pt. Ano Nuevo, the water mass Temperature-Salinity distribution tended to be organized along three branches. Off Pt. Ano Nuevo the innovative coastal observation network (ICON) model showed the formation of a cyclonic eddy during the analyzed upwelling period. In time the eddy moved southwest and became absorbed into the southerly flow during the initial phases of the following wind-relaxed period.