南海的平均T-S,S-Z,T-Z特性

本文根据美国国家大气海洋局国家海洋数据中心(NOAA,NODC)1966—1977年的历史水文资料,采用类似Emery和Dewar方法,计算南海每5°×5°经纬方格各标准层次的平均温度、盐度值及标准差,从而提供了各海区每隔0.5℃的温盐对应值和T-S,S-Z,T-Z曲线及标准偏差图。以便为今后进一步的调查,提供一个检验测量数据准确与否的基本依据。并通过对所划分的5个海区的T-S,T-Z,S-Z曲线的对比及标准偏差情况的分析,考察了各海区海水的物理特性,为进一步分析南海水体的运动、相互作用和变异提供了背景资料。

Long-term variabilities of thermodynamic structure of the East China Sea Cold Eddy in summer

Based on more than 30 years observed sectional temperature data since the 1960s, and compared with multi-year wind and Changjiang (Yangtze) River discharge data, spatial-temporal variations of the East China Sea Cold Eddy (ECSCE) in summer was analyzed in relationship to ocean circulation and local atmospheric circulation. Empirical Orthogonal Function (EOF) and Singular Value Decomposition (SVD) analyses were applied to this study. The results show that: 1) The ECSCE in summer possesses significant interannual variabilities, which are directly associated with oceanic and atmospheric circulation anomaly. Main fluctuations demonstrate their falling in basically with El Nino events (interannual) and interdecadal variability. 2) The ECSCE in summer is closely related to the variation of the Yellow Sea Warm Current (YSWC) and the Changjiang River discharge. The stronger the YSWC, the more intensive the ECSCE with its center shifting westward, and vice versa. However, a negative correlation between the Changjiang River discharge and the ECSCE strength is shown. The ECSCE was strengthened after the abrupt global climate change affected by the interdecadal variation of the YSWC. 3) SVD analysis suggested a high correlation between the variation of the ECSCE in summer and the anomalous cyclonic atmospheric circulation over the ECS. Intensification of the cyclonic wind strengthens the ECSCE, and vice versa. 4) The cyclonic atmospheric circulation has dominant influence on the interannual variation of the ECSCE, and the influence of the ocean circulation takes the second in. The ECSCE was usually stronger in El Nino years affected by strong cyclonic circulation in the atmosphere. The variation in strength of the ECSCE resulted from the joint effect of both oceanic and atmospheric circulation.

A temporal sliding procedure for ocean wave variational data assimilation and its application

For sequential performance of wave variational data assimilation, we proposed a temporal sliding method in which the temporal overlap is considered. The advantage of this method is that the initial wave spectrum of the optimization process is modified by the observations in latter and former times. This temporal sliding procedure is important for marginal region, such as the China seas, where the duration of assimilation effectiveness is 2-3 days. Experiments were performed in the whole course of Cyclone 9403 （Russ）. Around the cyclone center, the maximum value of wave elements did not change much by assimilation, because the extreme value was determined by wind energy input that was not yet optimized. In the area outside the cyclone center, this modification is evident especially for wind wave growth.

Shallow Water Body Data Processing Based on the Seismic Oceanography

Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other factors.To overcome the challenging difficulties in the quick monitoring of these physical properties,we have explored the high resolution marine seismic survey to instantly characterize them.Based on the unique wavefield propagating in the sea water,we have developed a new approach to suppress the noise caused by the shallow sea water disturbance and obtain useful information for estimating the sea water structure.This approach improves seismic data with high signal-to-noise ratio and resolution.The seismic reflection imaging can map the sea water structure acoustically.Combined with the knowledge of local water body structure profile over years,the instant model for predicting the sea water properties could be built using the seismic data acquired from the specially designed high precision marine seismic acquisition.This model can also be updated with instant observation and the complete data processing system.The present study has the potential value to many applications,such as 3D sea water monitoring,engineering evaluation,geological disaster assessment and environmental assessment.

Research of Marine Sensor Web Based on SOA and EDA

A great deal of ocean sensor observation data exists, for a wide range of marine disciplines, derived from in situ and remote observing platforms, in real-time, near-real-time and delayed mode. Ocean monitoring is routinely completed using sensors and instruments. Standardization is the key requirement for exchanging information about ocean sensors and sensor data and for comparing and combining information from different sensor networks. One or more sensors are often physically integrated into a single ocean ‘instrument' device, which often brings in many challenges related to diverse sensor data formats, parameters units, different spatiotemporal resolution, application domains, data quality and sensors protocols. To face these challenges requires the standardization efforts aiming at facilitating the so-called Sensor Web, which making it easy to provide public access to sensor data and metadata information. In this paper, a Marine Sensor Web, based on SOA and EDA and integrating the MBARI's PUCK protocol, IEEE 1451 and OGC SWE 2.0, is illustrated with a five-layer architecture. The Web Service layer and Event Process layer are illustrated in detail with an actual example. The demo study has demonstrated that a standard-based system can be built to access sensors and marine instruments distributed globally using common Web browsers for monitoring the environment and oceanic conditions besides marine sensor data on the Web, this framework of Marine Sensor Web can also play an important role in many other domains' information integration.

Modeling of the Bohai oilfield engineering geology demonstration information system based on digital seabed technology

In this paper, the framework and technologic process of engineering geology demonstration information system （EGDIS） of the Bohai oilfield are presented, and the key technologies for system modeling, such as storage and processing technology of multi-source and heterogeneous data, integrated display technology of multi-source information and multiple safeguard system design are studied. EGDIS of the Bohai oilfield is an integrated application system based on the data standardization and digital seabed database, has the function to realize the standardization/conformity, input/output, inquiry and display of the multi-source and heterogeneous data and graphics, and provides multiple comprehensive analysis and application services, which will provide shared and scientific basic data for the marine engineering construction and oilfield engineering safeguard.

The Impact of "Bad" Argo Profiles on Ocean Data Assimilation

Recent studies have found cold biases in a fraction of Argo profiles (hereinafter referred to as bad Array for Real-time Geostrophic Oceanography (Argo) profiles) due to the pressure drifts during 2003 and 2006. These bad Argo profiles have had an important impact on in situ observation-based global ocean heat content esti- mates. This study investigated the impact of bad Argo profiles on ocean data assimilation results that were based on observations from diverse ocean observation systems, such as in situ profiles (e.g., Argo, expendable bathy- thermograph (XBT), and Tropical Atmosphere Ocean (TAO), remote-sensing sea surface temperature products and satellite altimetry between 2004 and 2006. Results from this work show that the upper ocean heat content analysis is vulnerable to bad Argo profiles and demon- strate a cooling trend in the studied period despite the multiple independent data types that were assimilated. When the bad Argo profiles were excluded from the as- similation, the decreased heat content disappeared and a warming occurred. Combination of satellite altimetry and mass variation data from gravity satellite demonstrated an increase, which agrees well with the increased heat con- tent. Additionally, when an additional Argo profile quality control procedure was utilized that simply removed the profiles that presented static unstable water columns, the results were very similar to those obtained when the bad Argo profiles were excluded from the assimilation. This indicates that an ocean data assimilation that uses multiple data sources with improved quality control could be less vulnerable to a major observation system failure, such as a bad Argo event.

A statistical dynamics model of the marine ecosystem and its application in Jiaozhou Bay

Models of marine ecosystem dynamics play an important role in revealing the evolution mechanisms of marine ecosystems and in forecasting their future changes. Most traditional ecological dynamics models are established based on basic physical and biological laws, and have obvious dynamic characteristics and ecological significance. However, they are not flexible enough for the variability of environment conditions and ecological processes found in offshore marine areas, where it is often difficult to obtain parameters for the model, and the precision of the model is often low. In this paper, a new modeling method is introduced, which aims to establish an evolution model of marine ecosystems by coupling statistics with differential dynamics. Firstly, we outline the basic concept and method of inverse modeling of marine ecosystems. Then we set up a statistical dynamics model of marine ecosystems evolution according to annual ecological observation data from Jiaozhou Bay. This was done under the forcing conditions of sea surface temperature and surface irradiance and considering the state variables of phytoplankton, zooplankton and nutrients. This model is dynamic, makes the best of field observation data, and the average predicted precision can reach 90% or higher. A simpler model can be easily obtained through eliminating the terms with smaller contributions according to the weight coefficients of model differential items. The method proposed in this paper avoids the difficulties of obtaining and optimizing parameters, which exist in traditional research, and it provides a new path for research of marine ecological dynamics.

Effects of polarization calibration on aerosol optical depth retrieval: An ocean case sensitivity analysis

Reflectance measurements of both the visible and infrared bands of passive remote sensing sensors are widely used to retrieve aerosol optical depth(AOD) information. This is performed commonly for data obtained over both ocean and land, and these measurements allow for the off line development of a lookup table using radiative transfer models. Owing to molecular and aerosol effects, the reflected light received by the sensor is usually highly polarized. The linear polarization effect may be up to 100%, and the polarization factor of a sensor optical system will change the total intensity as well as the polarization status of the signal reaching the detector. The detector response will be different when the incident light polarization status changes, even if the total intensity remains constant. However, if the polarization calibration is neglected, it will cause obvious errors in the aerosol data retrieval. This is especially true for aerosol optical depth retrieval over an ocean. This measurement relies directly on the reflectance output of the sensor. Cases involving land surfaces are not discussed herein because the inhomogeneous properties conceal the error due to polarization. Taking the 550 and 860 nm bands as examples, the difference between the real top-of-atmosphere(TOA) reflectance and the reflectance reaching the detector is calculated using three different sensor polarization standards according to the Sea-viewing Wide Field-of-view Sensor(Sea Wi FS) and Moderate Resolution Imaging Spectroradiometer(MODIS) standards. The differences in AOD retrieval are also demonstrated using the lookup table developed previously from a vector radiative transfer code. The results reveal that under a normal situation in which the AOD is 0.15, the maximum AOD retrieval error could reach 0.04 in 550 nm but only 0.02 in 860 nm for the dust aerosol model. For the soot aerosol model, the maximum AOD retrieval error is 0.1 in 550 nm and 0.12 in 860 nm, indicating that the lack of polarization calibration will lead to large errors in aerosol retrieval over an ocean.