Numerical Modeling of Wave-Enhanced Turbulence in the Oceanic Upper Layer

A coupled model of air-wave-sea interaction is modified based on a new roughness formulation and the latest data. The model parameters for aerodynamic roughness from below (ARB) and wave-dependent roughness from above (ARA, z _0a ) are assumed equal. The combined roughness is assumed to be a function of friction velocity, gravity, air and seawater densities, and wave age (c _w ). The model is used in a study of wave-enhanced turbulence under breaking waves to predict turbulent dissipation (), ARA, and drag coefficient (C _d ). Both waves and shear production are considered as sources of ocean turbulent energy. The atmospheric part of the model is used only to specify a correct condition at the interface. Numerical experiments are performed to study the -distribution, z _0a and C _d , and to compare with data. The major achievement is model verification using all available data. The first full application of this model is in conjunction with an ocean circulation model in a coupled circulation-wave system. Simulations show that the -distribution is strongly dependent on local wind-forced wave heights. For each wind and wave state there is a particular wave-dependent depth that is verified by data. The comparison shows that the model predicted agrees well with the observed of the z ^–4 law distribution of Gargett (1989). Simulations also show that waves have an important role in causing to differ from the classical wall-layer theory and z _0a , with a value of 0.30 for the empirical constant a _a . The model-predicted , z _0a , C _d and C _gd agree well with data.     

海洋再分析资料中IOD-ENSO遥相关的海洋通道机制分析

本文利用滞后相关分析,研究了海洋再分析资料（SODA、ORAS4和GODAS）中的IOD-ENSO滞后遥相关关系,并与观测资料进行对比。结果显示,3套再分析资料中热带东南印度洋秋季海表温度/海表高度异常和赤道太平洋冷舌次年秋季海表温度/海表高度异常之间显著相关,与观测结果一致。在次表层,观测和再分析资料均显示,热带东南印度洋秋季海表温度异常与赤道太平洋次表层海温异常之间的显著相关关系在冬季至次年秋季沿赤道太平洋垂向剖面向东移动,并于次年夏季和秋季在冷舌区上升至海表。热带东南印度洋和赤道太平洋冷舌滞后1年的相关关系是由海洋通道机制引起的,即IOD事件引起印尼贯穿流流量异常,导致赤道太平洋温跃层异常,激发赤道Kelvin波向东传播,从而影响赤道中-东太平洋冷舌海表温度异常。观测及SODA与ORAS4资料中,热带东南印度洋和赤道太平洋冷舌滞后1年的相关关系在去除ENSO信号后仍然显著,表明海洋通道机制是独立于ENSO事件的;而在GODAS资料中,这些显著相关关系在去除ENSO信号后消失。印尼贯穿流流量异常和Niño3.4及DMI（Dipole Mode Index）指数之间超前-滞后12个月的相关关系显示,在SODA和ORAS4资料中,印尼贯穿流流量同时受到ENSO和IOD的影响,与观测结果一致;而在GODAS中,印尼贯穿流流量异常仅与Niño3.4指数显著相关,极少受到IOD事件的影响,这部分解释了GODAS资料中去除ENSO信号后,IOD-ENSO滞后遥相关关系消失的原因。     

The North Atlantic High-Resolution Regional Climate Model Experiment for Oceanic and Atmospheric Applications

We present a high-resolution historical analysis of the atmosphere over the North Atlantic for the period from January 1979 to December 2018. The dataset was obtained using the nonhydrostatic atmospheric model WRF-ARW version 3.8.1 and contains two experiments that differ in spatial resolution: 14 km (HiRes) and 77 km (LoRes). Except for the spatial resolution, the configuration remained identical in both experiments: 50 vertical sigma-levels (starting from ~12 m up to 50 hPa); ERA-Interim reanalysis was used as forcing and spectral nudging. The dataset for HiRes and LoRes experiments was named NAAD (North Atlantic Atmospheric Downscaling). Preliminary results of both HiRes and LoRes reveal good agreement with observations and the ERA-Interim, ERA5, and ASRv2 reanalyses. The NAAD dataset is available online at http://www.naad.ocean.ru and provides a variety of surface and upper-troposphere atmospheric variables with a time step of 3 h.

     

海气通量算法在海上蒸发波导诊断中的应用

利用TOGA COARE Bulk Air-Sea Flux Algorithm3.0,建立了基于通量算法的蒸发波导模型(Flux Evaporation duct Model),并进行了环境敏感性分析,而且与Paulus-Jeske模型对比,进行误差敏感性分析,并开展了雷达探测评估的海上试验,较全面的阐述了基于通量算法的蒸发波导模型的性能。     

4DVAR data assimilation in the Intra-Americas Sea with the Regional Ocean Modeling System (ROMS)

We present the background, development, and preparation of a state-of-the-art 4D variational (4DVAR) data assimilation system in the Regional Ocean Modeling System (ROMS) with an application in the Intra-Americas Sea (IAS). This initial application with a coarse model shows the efficacy of the 4DVAR methodology for use within complex ocean environments, and serves as preparation for deploying an operational, real-time assimilation system onboard the Royal Caribbean Cruise Lines ship Explorer of the Seas. Assimilating satellite sea surface height and temperature observations with in situ data from the ship in 14 day cycles over 2 years from January 2005 through March 2007, reduces the observation-model misfit by over 75%. Using measures of the Loop Current dynamics, we show that the assimilated solution is consistent with observed statistics.     

4DVAR data assimilation in the Intra-Americas Sea with the Regional Ocean Modeling System (ROMS)

We present the background, development, and preparation of a state-of-the-art 4D variational (4DVAR) data assimilation system in the Regional Ocean Modeling System (ROMS) with an application in the Intra-Americas Sea (IAS). This initial application with a coarse model shows the efficacy of the 4DVAR methodology for use within complex ocean environments, and serves as preparation for deploying an operational, real-time assimilation system onboard the Royal Caribbean Cruise Lines ship Explorer of the Seas. Assimilating satellite sea surface height and temperature observations with in situ data from the ship in 14 day cycles over 2 years from January 2005 through March 2007, reduces the observation-model misfit by over 75%. Using measures of the Loop Current dynamics, we show that the assimilated solution is consistent with observed statistics.     

基于星载微波辐射计的海洋大气参数反演算法研究

利用3个辐射传输模式对无冰无降水情况下的星载微波辐射计亮温测量进行仿真研究,通过模拟计算结果与同步卫星数据之间的比较分析,确定了用于反演算法研究的前向模式;利用该模式,提出了基于物理的星载微波辐射计海洋大气参数(包括海面风速、海表温度、大气垂直积分水汽量以及积分液态水量)多重线性回归算法。     

Modeling the dynamics of spring-driven oscillating-foil propulsion

In this paper we present a model for oscillating-foil propulsion in which springs are used to transmit forces from the actuators to the foil. The expressions for hydrodynamic force and moment on the foil come from classical, linear, unsteady aerodynamics, and these are coupled to linearized rigid-body mechanics to obtain the complete model for swimming. The model is presented as a low-order set of ordinary differential equations, which makes it suitable for the application of techniques from systems and control theory. The springs serve to reduce energy costs, and we derive explicit expressions for spring constants which are optimal in this sense. However, the use of springs can potentially lead to unstable dynamics. Therefore, we also derive a set of necessary and sufficient conditions for stability. A detailed example is presented in which energy costs for one actuator are reduced by 33%     

基于ARM的海洋站水文气象自动观测系统设计

针对国内现有的基于单片机或PC/104的数据采集系统的不足,介绍了一种基于ARM(Advanced RISCMachines)平台和单片机平台的数据采集系统。它结合了国外先进的数据采集技术,具有功耗低、体积小、性能高,软、硬件扩充灵活的特点,其通用性、模块化和可扩展性能满足浮标、船用气象仪等海洋水文气象仪器设备研发的需求。     

Modeling the Regional Influence of Ions on Aerosol Formation in the Atmosphere

Izvestiya, Atmospheric and Oceanic Physics - The results of numerical calculations of the variability of number concentrations of aerosol particles of different sizes and the rates of ion-induced...     

中国海洋观的变迁

结合海洋观内涵,阐述不同时期中国海洋观的特征;结合世界海洋发展的潮流,联系中国海洋经济发展的实际,强调更新海洋观的必要性,总结了我国新海洋观应该具备的特征.     

A review of the National Oceanic Satellite System (NOSS) and prospects for ocean remote sensing in the near future

Abstract

The concept of sensing oceanic parameters from space has been clearly demonstrated by the data from NASA's SEASAT. As the next step, a triagency team from NASA, NOAA, and DOD developed a program for a national system, the National Oceanic Satellite System (NOSS). The NOSS was to be an end‐to‐end system, a five‐year quasi‐operational demonstration to satisfy the most critical of the user agencies (NOAA and Navy) requirements for oceanographic data. Unfortunately, NOSS became an early victim of the Administration's efforts to reduce the Federal budget. The search for less costly (less capable) alternatives continues. In the meantime, the accuracy of our operational forecasts suffers and critical requirements go unsatisfied.     

海洋中DMSP的研究进展

DMSP(dimethylsulfoniopropionate，β-二甲基巯基丙酸内盐)作为DMS(dimethylsulfide,二甲基硫)的前体，是1种重要的生源硫化物。根据其在海洋生态系统和生物地球化学循环中所起着的重要作用，作者综述了国内外海洋科学工作者十几年来在EMSP研究方面的进展。     

Weak and strong constraint data assimilation in the inverse Regional Ocean Modeling System (ROMS): Development and application for a baroclinic coastal upwelling system

We describe the development and preliminary application of the inverse Regional Ocean Modeling System (ROMS), a four dimensional variational (4DVAR) data assimilation system for high-resolution basin-wide and coastal oceanic flows. Inverse ROMS makes use of the recently developed perturbation tangent linear (TL), representer tangent linear (RP) and adjoint (AD) models to implement an indirect representer-based generalized inverse modeling system. This modeling framework is modular. The TL, RP and AD models are used as stand-alone sub-models within the Inverse Ocean Modeling (IOM) system described in [Chua, B.S., Bennett, A.F., 2001. An inverse ocean modeling system. Ocean Modell. 3, 137–165.]. The system allows the assimilation of a wide range of observation types and uses an iterative algorithm to solve nonlinear assimilation problems. The assimilation is performed either under the perfect model assumption (strong constraint) or by also allowing for errors in the model dynamics (weak constraints). For the weak constraint case the TL and RP models are modified to include additional forcing terms on the right hand side of the model equations. These terms are needed to account for errors in the model dynamics.Inverse ROMS is tested in a realistic 3D baroclinic upwelling system with complex bottom topography, characterized by strong mesoscale eddy variability. We assimilate synthetic data for upper ocean (0–450 m) temperatures and currents over a period of 10 days using both a high resolution and a spatially and temporally aliased sampling array. During the assimilation period the flow field undergoes substantial changes from the initial state. This allows the inverse solution to extract the dynamically active information from the synthetic observations and improve the trajectory of the model state beyond the assimilation window. Both the strong and weak constraint assimilation experiments show forecast skill greater than persistence and climatology during the 10–20 days after the last observation is assimilated.Further investigation in the functional form of the model error covariance and in the use of the representer tangent linear model may lead to improvement in the forecast skill.     

一种公共交通的最优路径算法

在总结公交网络特点的基础上,提出了运用“燃烧”算法来计算公共交通系统的最优路径算法.并用一个简化的例子来说明这种算法的流程,最后结合北京公交网络的一些数据,对这种算法以及经典的Dijkstra算法做了几点比较,无论在空间还是时间复杂度上这种算法都大大优于Dijkstra算法.     

Modeling of ocean dynamics with large variations in sea level

The formulation and the algorithm of solving an ocean model for the prediction and assimilation of the observed data which makes it possible to reconstruct the circulation in the deep-water parts of the sea and at a shallow water shelf, as well as to describe the large time–space variability in the surface level, are considered. The model uses a vertical hybrid σ–z coordinate system: the several upper tens of meters of the ocean are described in the σ-coordinate system and the rest of the water column is described in the z coordinates. Such hybridization extends the possibilities of models for reconstructing thermo-hydrodynamic processes in different sea basins and the World Ocean. The differential formulation of the model in the σ–z coordinate system is presented; the simplified records of several operators that are allowable in the case of a small thickness of the ocean σ-layer are described. The construction of a computational grid, approximation of the bottom topography on it, and discretization of equations and boundary conditions of the models are considered; an approach to describing the bottom friction at shallow waters is offered. The results of the comparative experiments in the z and σ–z coordinate models are analyzed.     

4DVAR Data Assimilation with the Regional Ocean Modeling System (ROMS): Impact on the Water Mass Distributions in the Yellow Sea

In this study, we evaluate the performance of the recently developed incremental strong constraint 4-dimensional variational (4DVAR) data assimilation applied to the Yellow Sea (YS) using the Regional Ocean Modeling System (ROMS). Two assimilation experiments are compared: assimilating remote-sensed sea surface temperature (SST) and both the SST and in-situ profiles measured by shipboard CTD casts into a regional ocean modeling from January to December of 2011. By comparing the two assimilation experiments against a free-run without data assimilation, we investigate how the assimilation affects the hydrographic structures in the YS. Results indicate that the SST assimilation notably improves the model behavior at the surface when compared to the non-assimilative free-run. The SST assimilation also has an impact on the subsurface water structure in the eastern YS; however, the improvement is seasonally dependent, that is, the correction becomes more effective in winter than in summer. This is due to a strong stratification in summer that prevents the assimilation of SST from affecting the subsurface temperature. A significant improvement to the subsurface temperature is made when the in-situ profiles of temperature and salinity are assimilated, forming a tongue-shaped YS bottom cold water from the YS toward the southwestern seas of Jeju Island.     

基于海温遥感资料的海洋锋检测方法

介绍了海洋锋的特点和本文选用的资料源,详细研究了海洋锋检测算法,给出了梯度和锋线检测结果,最后分析了东海黑潮锋季节变化规律,为基于海温遥感资料的海洋锋检测方法业务化应用提供参考。     

Oceanic Velocity Microstructure Measurements in the 20th Century

The science of ocean turbulence was started more than 50 years ago by a small research group using a surplus mine-sweeping paravane to measure the velocity and temperature fluctuations in the ocean. The field has grown considerably and measurements are now conducted by researchers in many countries. A wide variety of sophisticated instrument systems are used to profile horizontally and vertically through the marine environment. Here we review the historical development of velocity micro-structure profiles over the past four decades and summarize the basic requirements for successful measurements. We highlight critical technological developments and glance briefly at some of the scientific discoveries made with these instruments. This revised version was published online in August 2006 with corrections to the Cover Date.     

海洋站观测资料的质量控制方法及其应用

文章阐明开展海洋站观测资料质量控制的必要性和重要性,以海洋站观测延时(月报)资料为例,详细论述其质量控制的对象、流程和参数以及包括日期检验、位置检验、格式检验在内的19种质量控制方法,同时概述海洋站观测资料质量控制软件,最后提出下一步开展海洋站观测资料的均一化检验和订正以及建立多模式检验系统和均一化数据集的研究重点,以期为海洋和气候变化研究提供科学准确的第一手资料。