Upper Ocean Physical and Biological Response to Typhoon Cimaron (2006) in the South China Sea

Upper Ocean Physical and Biological Response to Typhoon Cimaron (2006) in the South China Sea
Author: Yujuan Sun
Publisher:
Total Pages:
Release: 2016
Genre: Technology
ISBN:

The physical dynamic and biological response processes to Typhoon Cimaron (2006) in the South China Sea are investigated through the three-dimensional Regional Ocean Modeling System (ROMS). For sea surface temperatures, ROMS achieves a correlation of more than 0.84, with respect to satellite observations, indicating a generally high level of skill for simulating the sea surface temperature variations during Typhoon Cimaron (2006). However, detailed analysis shows that ROMS underestimates the sea surface temperature cooling and mixed layer deepening because of insufficient mixing in the model simulations. We show that the simulation accuracy can be enhanced by adding a wave-induced mixing term (BV) to the nonlocal K-profile parameterization (KPP) scheme. Simulation accuracy is needed to investigate nutrients, which are deeply entrained to the oligotrophic sea surface layer by upwelling induced by Typhoon Cimaron, and which plays a remarkable role in the subsequent phytoplankton bloom. Simulations show that the phytoplankton bloom was triggered 5 days after the passage of the storm. The surface ocean was restored to its equilibrium ocean state by about 10-20 days after the typhoon's passage. However, on this time-scale, the resulting concentrations of nitrate and chlorophyll a remained higher than those in the pre-typhoon equilibrium.

Ocean Circulation and Air-Sea Interaction in the South China Sea

Ocean Circulation and Air-Sea Interaction in the South China Sea
Author: Dongxiao Wang
Publisher: Springer Nature
Total Pages: 448
Release: 2022-10-28
Genre: Science
ISBN: 9811962626

This book summarizes achievements of the study on circulation and air–sea interaction and development of the ocean observation network in the South China Sea in the last 20 years, thus serving as a comprehensive reference book to understand the dynamic environment in the SCS. It consists of seven chapters, briefly reviewing our understanding of the SCS circulation and air–sea interaction in chapter 1, then describing in detail the upper layer circulation from large scale (SCS through flow, SCS western boundary current, etc.), to meso- and submeso-scale in Chapters 2 and 5, dilute river plume and coastal upwelling over the shelf in Chapter 3, deep ocean circulation in Chapter 4, tropical cyclone activities and air–sea flux at the interface in Chapter 6, and the construction of the observation network and database in Chapter 7. Besides the basic features of these physical processes, the book also discusses their variations and fundamental dynamics. Thus, it is written in a way that meets the different information demands from researchers working in various marine related fields.

Studies of the South China Sea Circulation and Thermal Structure Using a Three Dimensional Numerical Model

Studies of the South China Sea Circulation and Thermal Structure Using a Three Dimensional Numerical Model
Author: Nathan L. Edmons
Publisher:
Total Pages: 122
Release: 1996
Genre: Science
ISBN:

The seasonal ocean circulation and thermal structure in the South China Sea (SCS) were studied numerically using the Princeton Ocean Model (POM) with 20 km horizontal resolution and 23 sigma levels conforming to a realistic bottom topography. A sixteen month control run was performed using climatological monthly mean wind stresses and restoring type salt and heat fluxes as surface forcing terms and observational oceanic inflow/outflow at the open boundaries. The seasonally averaged effects of isolated forcing terms are presented and analyzed from the following experiments: 1) non-linear effects removed, 2) wind effects removed, 3) open boundary inflow/outflow set to zero, and 4) open boundary inflow/outflow doubled. This procedure allowed analysis of spatial and temporal contributions of the isolated parameter to the general hydrology of the SCS and some of its specific features. A coastal jet is identified and analyzed, as are a mesoscale topographic gyre and several counter currents. Non-linearity is shown to be important to the energy and volume transport of baroclinic eddy features, but otherwise insignificant. Boundary transport from open lateral boundaries is determined to be of considerable importance to summer circulation and thermal structure, with little effect found for the winter monsoon hydrology. In general, monsoonal circulation patterns and upwelling phenomena are determined and forced by the wind, while boundary transport effects play a secondary role in determining the magnitude of the circulation velocities.

Regional Oceanography Of The South China Sea

Regional Oceanography Of The South China Sea
Author: Jianyu Hu
Publisher: World Scientific
Total Pages: 500
Release: 2020-06-24
Genre: Science
ISBN: 9811206929

This book aims to share newly obtained results and information on regional oceanography of the South China Sea by leading experts in fields such as water mass, circulation, mesoscale eddies, near-inertial motion, upwelling, mixing, continental shelf waves, internal waves and fronts. These comprehensive results can provide new insights on global and regional climate change.

Response of the South China Sea to Forcing by Tropical Cyclone Ernie (1996)

Response of the South China Sea to Forcing by Tropical Cyclone Ernie (1996)
Author: Joseph M. Veneziano
Publisher:
Total Pages: 180
Release: 1998-03-01
Genre:
ISBN: 9781423562030

The South China Sea (SCS) response to forcing by Tropical Cyclone Ernie (1996) was studied numerically using the Princeton Ocean Model (POM) with 20 km horizontal resolution and 23 sigma levels conforming to a realistic bottom topography. A fourteen day experiment was conducted using a wind model that allowed for temporal variations of its translational speed, size and intensity. Restoring type salt and heat fluxes were used along with seasonal inflow/outflow at the open boundaries. The POM adequately simulated ocean responses to tropical cyclone forcing. Near-surface ocean responses simulated by the POM included strong asymmetrical divergent currents with near-inertial oscillations, significant sea surface temperature cooling, biased to the right of the storm track, and sea surface depressions in the wake of the storm. Subsurface responses included intense upwelling and cooling at the base of the mixed layer to the right of the storm track. Several unique features, caused by coastal interactions with storm forcing, were also simulated by the model. Along the coast of Luzon a sub-surface alongshore jet was formed, a warm anomaly off the northern tip of Luzon was significantly enhanced by surface layer convergence and storm surges simulated along the coasts of Luzon and Vietnam.

Major Law and Policy Issues in the South China Sea

Major Law and Policy Issues in the South China Sea
Author: Yann-huei Song
Publisher: Routledge
Total Pages: 446
Release: 2016-05-13
Genre: History
ISBN: 131710269X

Major law and policy issues in the South China Sea are discussed mainly from the perspectives of leading American and European scholars in the study of the complex South China Sea disputes. The issues include regional maritime cooperation and regime building, Southeast Asian countries’ responses to the Chinese assertiveness, China’s historic claims, maritime boundary delimitation and excessive maritime claims, military activities and the law of the sea, freedom of navigation and its impact on the problem, the dispute between Vietnam and China, confidence-building measures and U.S.-Taiwan-China relations in the South China Sea, and Taiwan’s role in the resolution to the South China Sea issues. Over the past three years, there have been several incidents in the South China Sea between the claimants, and also between the claimants and non-claimants over fisheries, collection of seismic data, exploration for oil and gas resources, and exercise of freedom of navigation. Third party concerns and involvement in the South China Sea disputes have been increasing as manifested in actions taken by the United States, India, and Japan. It is therefore important to examine South China Sea disputes from the legal and political perspective and from the view point of American and European experts who have been studying South China Sea issues for many years.

Response of the Southern Ocean Circulation to Changes in Global Climate

Response of the Southern Ocean Circulation to Changes in Global Climate
Author: Adele Kim Morrison
Publisher:
Total Pages: 158
Release: 2014
Genre: Climatic changes
ISBN:

The Southern Ocean circulation plays a central role in the dynamics of past and future global climate change. However, due to a scarcity of observations and the difficulty of accurately modelling the Southern Ocean, we lack a comprehensive understanding of how the circulation responds to change. The energetic eddy field directly impacts the response of the circulation, but the small scale of the eddies has generally been below the resolution of numerical ocean models. This thesis makes use of two high resolution idealised ocean models to investigate the role of eddies in modifying the response of the Southern Ocean circulation to changing wind stress and surface buoyancy forcing. The simulations demonstrate that the eddy field is significant in the dynamical response, but that the impact on different aspects of the circulation is complex and subtle. The Antarctic Circumpolar Current (ACC) transport increases only weakly in response to enhanced Southern Ocean wind stress, due to the enhanced eddy field, which efficiently eliminates momentum input. In contrast, the eddy field only partially compensates wind- driven increases in the upper overturning circulation, resulting in a moderate overturning increase in response to enhanced westerly winds. Southern Ocean heat uptake is also shown to be dependent on changes in the eddy field. Mid-depth warming occurs primarily due to a decrease in the upward eddy heat flux, associated with reduced isopycnal temperature gradients in a warmer climate. However, increased wind stress may reduce the mid-depth heat uptake; a transient cooling trend arises from the wind-driven enhancement of the vertical eddy heat flux. The uncoupled idealised models also permit an in-depth analysis of the response of the Southern Ocean overturning to changes in surface buoyancy forcing. A suite of buoyancy forcing perturbations show that mid-latitude heat and freshwater fluxes may be as significant as wind stress in altering the strength of the upper overturning circulation. Analysis of the transient model response to a range of surface buoyancy forcing perturbations also indicates that recent observations are consistent with a slowdown of the lower overturning cell. In summary, this thesis has refined our understanding of how the large scale Southern Ocean circulation responds to atmospheric change and the role of the eddy field in modifying that response. This work provides a basis to interpret the more complicated response of coupled and coarse resolution models.