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An Oceanic General Circulation Model in Pressure Coordinates

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Advances in Atmospheric Sciences 2001年第1期18卷 1-22页

作者：黄瑞新金向泽张学洪 Department of Physical Oceanography Woods Hole Oceanographic Institution Woods Hole LASG Institute of Atmospheric Physics Chinese Academy of Sciences

A new oceanic general circulation model in pressure coordinates is formulated. Since the bottom pressure changes with time, the vertical coordinate is actually a pressure-sigma coordinate. The numerical solution of the model is based on an energy-conservation scheme of finite difference. The most important new feature of the model is that it is a truly compressible ocean model and it is free of the Boussinesq approximations. Thus, the new model is quite different from many existing models in the following ways: 1) the exact form of mass conservation, 2) the in-situ instantaneous pressure and the UNESCO equation of state to calculate density, 3) the in-situ density in the momentum. equations, 4) finite difference schemes that conserve the total energy. Initial tests showed that the model code runs smoothly, and it is quite stable. The quasi-steady circulation patterns generated by the new model compare well with existing models, but the time evolution of the new model seems different from some existing models. Thus, the non-Boussinesq models may provide more accurate information for climate study and satellite observations.

关键词： non Boussinesq pressure coordinates mase-conserving model

Magmatism and tectonic processes in Area A hydrothermal vent on the Southwest Indian Ridge

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Science China Earth Sciences 2013年第12期56卷 2186-2197页

作者： ZHANG Tao LIN Jian GAO JinYao Second Institute of Oceanography State Oceanic Administration Key Laboratory of Submarine Geosciences State Oceanic Administration Department of Geology and Geophysics Woods Hole Oceanographic InstitutionWoods HoleMA 02543USA

The hydrothermal vent in Area A （37.78°S, 49.65°E） is the first active hydrothermal vent discovered on the Southwest Indian Ridge （SWlR）. Heat source and adequate bulk permeability are two necessary factors for the formation of a hydrothermal vent. Along the SWIR 49.3°E to 51.2°E, the gravity-derived crustal thickness is up to 9.0 km, much thicker than the average thick- ness of the global oceanic crust. This characteristic indicates that the magma supply in this area is robust, which is possibly af- fected by a hotspot. The large-scale residual mantle Bouguer anomalies （RMBA） reveal prominent negative-gravity anomalies between the first-order ridge segment （from Indomed to Gallieni, 46.0°E to 52.0°E） and the Marion-Del Cano-Crozet region. These anomalies indicate the channel of the hotspot-ridge interaction. The tomography data corrected with theoretical thermal model indicate that the low-velocity anomalies corresponding to this channel can reach the base of the lithosphere. Near the hydrothermal vent area, the topography and crustal thickness at the off-axis area are extremely asymmetrical. South of the SWIR, the high topography corresponds to the thinning crustal thickness. The residual isostatic topography anomalies indicate that Area A is a deviation from the local isostatic equilibrium, similar to the characteristics of the transform fault inside corner. The forward profiles of the magnetic data indicate that the thinning magnetic layer at the south side of Area A corresponds to the shallow, high-velocity area revealed by the OBS, which is the result of tectonic extension of a detachment fault. The active tectonic processes in Area A can provide sufficient crustal permeability to the hydrothermal circulation and may form massive sulfide deposits.

关键词： ultra-slow spreading ridge Area A hydrothermal vent RMBA hotspot-ridge interaction detachment fault

Post Cryopreservation Growth Kinetic and Photosynthetic Assessment of an Acid Tolerant Strain of Stichococcus bacillaris

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Natural Resources 2024年第5期15卷 130-148页

作者： Marzia Licata Luigi Marra Nunzia Nappi Elena Aurino Feliciana Oliva Antonino De Natale Donato Giovannelli Antonino Pollio Department of Biology University of Naples &#8220Federico II&#8221 Naples Italy ACUF Algal Collection of University of Naples &#8220Federico II&#8221 Naples Italy Department of Chemical Materials and Industrial Production Engineering University of Naples &#8220Federico II&#8221 P.le V. Tecchio Naples Italy Institute for Marine Biological Resources and Biotechnologies Italian National Research Council CNR-IRBIM Ancona Italy Earth-Life Science Institute ELSI Tokyo Institute of Technology Tokyo Japan Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA USA Department of Marine and Coastal Science Rutgers University New Brunswick NJ USA

Preserving microbial diversity has become a strategic undertaking. Thus, ex situ microalgal culture conservation results in strategic and functional resource in both biodiversity protection and application domains. Cryopreservation of microalgae has been practiced since the 1960s and is now considered the optimal preservation strategy. Furthermore, the overall monitoring during growth of cultures after freezing/thawing protocols was hardly investigated and there is poor evaluation related to preserve especially the photosystem apparatus. The present study focuses on Stichococcus bacillaris as case study for short-term cryopreservation at −80 °C storage. Various freezing pretreatments using cryoprotective agents, and two thawing methods were compared introducing a novel variable to evaluate viability recovery and assessing growth kinetics of cultures immediately after thawing and after a series batch cultivation. Photosynthetic rate and pigments assessment were proposed to evaluate hidden metabolic cell damage. Results underline cryoprotective agents can increase the kinetic recovery of preserved cells in terms of reduction of lag phase during batch cultivation tests: the use of dimethyl sulfoxide and glycerol granted a growth comparable to unpreserved cells when sudden thawing occurs after 24 hours of storage, but recovery after preservation is less sensitive to cryoprotective agents when gradual thawing and 1 month of storage is considered. However, cells are always able to restore their physiological pathways even without agents, so their kinetic effect has been proved and quantified. Interestingly, both the photosynthetic efficiency and the ratio between total chlorophyll and carotenoids are comparable (0.75 Fv/Fm, 2.2 ± 0.25 g/g) to unpreserved cells and they are unsensitive to chosen agents, but the ratio between chlorophyll a and chlorophyll b was clearly altered (up to 10 times), suggesting that photoactive pigments relative proportions

关键词： Microalgae Stichococcus bacillaris Cryopreservation Growth Kinetic Photosynthetic Rate

Energetics of lateral eddy diffusion/advection: Part III. Energetics of horizontal and isopycnal diffusion/ advection

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Acta Oceanologica Sinica 2014年第3期33卷 40-57页

作者： HUANG Rui Xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Gravitational Potential Energy （GPE） change due to horizontal/isopycnal eddy diffusion and advection is examined. Horizontal/isopycnal eddy diffusion is conceptually separated into two steps： stirring and sub scale diffusion. GPE changes associated with these two steps are analyzed. In addition, GPE changes due to stirring and subscale diffusion associated with horizontal/isopycnal advection in the Eulerian coordinates are analyzed. These formulae are applied to the SODA data for the world oceans. Our analysis indicates that horizontal/isopycnal advection in Eulerian coordinates can introduce large artificial diffusion in the model. It is shown that GPE source/sink in isopycnal coordinates is closely linked to physical property distribution, such as temperature, salinity and velocity. In comparison with z-coordinates, GPE source/sink due to stir ring/cabbeling associated with isopycnal diffusion/advection is much smaller. Although isopycnal coordi nates may be a better choice in terms of handling lateral diffusion, advection terms in the traditional Eule rian coordinates can produce artificial source of GPE due to cabbeling associated with advection. Reducing such numerical errors remains a grand challenge.

关键词： energetics of horizontal eddy diffusion energetics of horizontal advection energetics ofisopycnal eddy diffusion energetics of isopycnal advection

Energetics of lateral eddy diffusion/advection: Part I. Thermodynamics and energetics of vertical eddy diffusion

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Acta Oceanologica Sinica 2014年第3期33卷 1-18页

作者： HUANG Rui Xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Two important nonlinear properties of seawater thermodynamics linked to changes of water density, cab beling and elasticity （compressibility）, are discussed. Eddy diffusion and advection lead to changes in den sity; as a result, gravitational potential energy of the system is changed. Therefore, cabbeling and elasticity play key roles in the energetics of lateral eddy diffusion and advection. Vertical eddy diffusion is one of the key elements in the mechanical energy balance of the global oceans. Vertical eddy diffusion can be con ceptually separated into two steps： stirring and subscale diffusion. Vertical eddy stirring pushes cold/dense water upward and warm/light water downward; thus, gravitational potential energy is increased. During the second steps, water masses from different places mix through subscale diffusion, and water density is increased due to cabbeling. UsingWOA01 climatology and assuming the vertical eddy diffusivity is equal to a constant value of 2x103 pa2/s, the total amount of gravitational potential energy increase due to vertical stirring in the world oceans is estimated at 263 GW. Cabbeling associated with vertical subscale diffusion is a sink of gravitational potential energy, and the total value of energy lost is estimated at 73 GW. Therefore, the net source of gravitational potential energy due to vertical eddy diffusion for the world oceans is estimated at 189 GW.

关键词： cabbeling compressibility elasticity energetics of vertical eddy diffusion gravitationalpotential energy parameterization of eddy diffusion

Energetics of lateral eddy diffusion/advection: Part II. Numerical diffusion/diffusivity and gravitational potential energy change due to isopycnal diffusion

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Acta Oceanologica Sinica 2014年第3期33卷 19-39页

作者： HUANG Rui Xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Study of oceanic circulation and climate requires models which can simulate tracer eddy diffusion and ad vection accurately. It is shown that the traditional Eulerian coordinates can introduce large artificial hori zontal diffusivity/viscosity due to the incorrect alignment of the axis. Therefore, such models can smear sharp fronts and introduce other numerical artifacts. For simulation with relatively low resolution, large lateral diffusion was explicitly used in models; therefore, such numerical diffusion may not be a problem. However, with the increase of horizontal resolution, the artificial diffusivity/viscosity associated with hori zontal advection in the commonly used Eulerian coordinates may become one of the most challenging ob stacles for modeling the ocean circulation accurately. Isopycnal eddy diffusion （mixing） has been widely used in numerical models. The common wisdom is that mixing along isopycnal is energy free. However, a careful examination reveals that this is not the case. In fact, eddy diffusion can be conceptually separated into two steps： stirring and subscale diffusion. Due to the thermobaric effect, stirring, or exchanging water masses, along isopycnal surface is associated with the change of GPE in the mean state. This is a new type of instability, called the thermobaric instability. In addition, due to cabbeling subscale diffusion of water parcels always leads to the release of GPE. The release of GPE due to isopycnal stirring and subscale diffusion may lead to the thermobaric instability.

关键词： Eulerian coordinates numerical diffusivity numerical dissipation energetics of isopycnal eddydiffusion

Energetics of lateral eddy diffusion/advection: Part IV. Energetics of diffusion/advection in sigma coordinates and other coordinates

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Acta Oceanologica Sinica 2014年第3期33卷 58-78页

作者： HUANG Rui Xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Gravitational potential energy （GPE） source and sink due to stirring and cabbeling associated with sigma dif fusion/ advection is analyzed. It is shown that GPE source and sink is too big, and they are not closely linked to physical property distribution, such as temperature, salinity and velocity. Although the most frequently quoted advantage of sigma coordinate models are their capability of dealing with topography; the exces sive amount of GPE source and sink due to stirring and cabbeling associated with sigma diffusion/advec tion diagnosed from our analysis raises a very serious question whether the way lateral diffusion/advection simulated in the sigma coordinates model is physically acceptable. GPE source and sink in three coordinates is dramatically different in their magnitude and patterns. Overall, in terms of simulating lateral eddy diffu sion and advection isopycnal coordinates is the best choice and sigma coordinates is the worst. The physical reason of the excessive GPE source and sink in sigma coordinates is further explored in details. However, even in the isopycnal coordinates, simulation based on the Eulerian coordinates can be contaminated by the numerical errors associated with the advection terms.

关键词： energetics of horizontal advection energetics of horizontal eddy diffusion energetics ofisopycnal advection energetics of isopycnal eddy diffusion energetics of sigma advectiondiffusion energetics of sigma eddy diffusion

Three-Dimensional Density Distribution and Seismic Activity along the Guxiang–Tongmai Segment of the Jiali Fault,Tibet

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 454-467页

作者： FAN Pengxiao YU Changqing WANG Ruixue ZENG Xiangzhi QU Chen ZHANG Yue Institute of Land and Resources Engineering Kunming University of Science and Technology Kunming 650000China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Jiangsu Donghai Continental Deep hole Crustal Activity National Observation and Research StationLianyungangJiangsu 222000China

The Guxiang-Tongmai segment of the Jiali fault is situated northeast of the Namche Barwa Syntaxis in northeastern *** is one of the most active strike-slip faults near the syntaxis and plays a pivotal role in the examination of seismic activity within the eastern Himalayan *** study in the research region has yielded a 1:200000 gravity dataset covering an area 1500 km^(2).Using wavelet transform multiscale decomposition,scratch analysis techniques,and 3D gravity inversion methods,gravity anomalies,fault distributions,and density structures were determined across various *** the integration of our new gravity data with other geophysical and geological information,our findings demonstrate substantial variations in the overall crustal density within the region,with the fault distribution closely linked to these density *** in stratigraphic density are important causes of variations in the capacity of geological formations to endure regional tectonic *** are predominantly concentrated within the density transition zone and are primarily situated in regions of elevated *** hanging wall stress within the Guxiang-Tongmai segment of the Jiali fault exhibits a notable concentration,marked by pronounced anisotropy,and is positioned within the density differential zone,which is prone to earthquakes.

关键词： seismicity deep-density structure wavelet transform multi-scale decomposition scratch analysis 3D gravity inversion Jiali fault Tibet

Meso-scale available gravitational potential energy in the world oceans

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Acta Oceanologica Sinica 2006年第5期25卷 1-13页

作者： FENG Yang WANG Wei HUANG Ruixin Physical Oceanography Laboraltory Ocean University of China Qingdao 266003 China Department of Physical Oceanography Woods Hole Oceanographic Institution Woods Hole MA 02543 USA

The pitfalls of applying the commonly used definition of available gravitational potential energy （AGPE） to the world oceans are re-examined. It is proposed that such definition should apply to the meso-scale problems in the oceans, not the global scale. Based on WOA98 climatological data, the meso-scale AGPE in the world oceans is estimated. Unlike previous results by Oort et al. , the meso-scale AGPE is large wherever there is a strong horizontal density gradient. The distribution of meso-scale AGPE reveals the close connection between the baroclinic instability and the release of gravitational potential energy stored within the scale of Rossby deformation radius.

关键词： energy of ocean circulation available potential gravitational energy meso-scale baroclinic instability Rossby deformation radius