Abyssal Circulation in the Philippine Sea     

Fangguo Zhai  Yanzhen Gu 《中国海洋大学学报(英文版)》2020,19(2):249-262

The abyssal circulation in the Philippine Sea(PS)is investigated,with outputs from the Simple Ocean Data Assimilation version 2.2.4(SODA224).The deep-water currents in SODA224 are carefully evaluated,with sparse in situ observations in the North Pacific Ocean.In the upper deep layer(20003000 m)of the PS,a strong westward current,which originates from the Northeast Pacific Basin and enters the PS through the Yap-Mariana Junction,exists along 1114 N.This strong westward current bifurcates into two western boundary currents off the Philippines.The northward-flowing current flows out of the PS around 2021 N,whereas the southward-flowing current transports deep water from the northern hemisphere to the southern hemisphere.In the lower deep layer(30004500 m),the inflow water first flows northward to the east of the Western Mariana Basin and then turns westward at approximately 18 N.The inflow water mainly enters the Philippine Basin(PB),with a small part turning southward to constitute a weak cyclonic circulation.The water entering the PB mainly merges into a strong southward western boundary current in the south-ern PB.In the bottom layer(below 4500 m),both the northeast and northwest PB show single cyclonic gyres,whereas the south PB shows a single anticyclonic gyre.Moreover,comparisons with the observations indicate the possible existence of a cyclonic sense of circulation over the Philippine Trench.The current study provides the implications for future observations,which are needed to fur-ther investigate the temporospatial variations of the abyssal circulation in the PS on multiple scales.  相似文献   

Upper Ocean Response and Feedback Mechanisms to Typhoon     

Chen Dake  Lei Xiaotu  Wang Wei  Wang Guihua  Han Guijun  Zhou Lei 《地球科学进展》2013,28(10):1077-1086

This paper is an introduction to a new project of the national basic research program of China, “Upper Ocean Response Feedback Mechanisms to Typhoon”. The importance and necessity of this project, regarding the national interests, are discussed at the beginning. Then, the ocean typhoon interaction is proposed as a cutting-edge research topic, in terms of the physical mechanism, data assimilation method, and forecast technique. Latest research progresses are reviewed on the oceanic response and feedback to typhoon, the large scale interaction between the ocean and typhoon, the multi source ocean data assimilation related to typhoon, and typhoon forecast model. Finally, the key scientific questions and the major research contents are presented. bstract: This paper is an introduction to a new project of the national basic research program of China, “Upper Ocean Response and Feedback Mechanisms to Typhoon”. The importance and necessity of this project, regarding the national interests, are discussed at the beginning. Then, the ocean typhoon interaction is proposed as a cutting-edge research topic, in terms of the physical mechanism, data assimilation method, and forecast technique. Latest research progresses are reviewed on the oceanic response and feedback to typhoon, the large scale interaction between the ocean and typhoon, the multi source ocean data assimilation related to typhoon, and typhoon forecast model. Finally, the key scientific questions and the major research contents are presented.  相似文献   

基于数据字典的MapGIS属性数据逻辑检查——以全国矿产资源潜力评价基础成果数据检查为例   总被引：1，自引：0，他引：1       下载免费PDF全文

汪新庆  冯磊 《江苏地质》2013,37(3):478-481

在"全国矿产资源潜力评价"项目的基础成果数据验收汇总工作中,保证属性数据的填写质量是非常重要的一个环节,在专业领域内属性数据之中存在着一定的逻辑关系,可以通过计算机程序实现的方式检查数据是否存在着逻辑上的错误。在MapGIS 67二次开发环境下利用VC编程语言实现了属性数据逻辑检查程序,该程序基于数据字典技术,通过调用用户已设定的逻辑关系表达式对潜力评价基础数据进行属性逻辑检查,并将检查结果以报表的形式导出,大大提高了图件的检查验收工作的效率,并保证了数据的准确性与可靠性。该项技术已经成功应用于全国矿产资源潜力评价项目中稀土矿和钨矿的汇总工作。  相似文献   

In-flight calibration of the Dawn Framing Camera     

S.E. Schröder  T. Maue  P. Gutiérrez Marqués  S. Mottola  K.M. Aye  H. Sierks  H.U. Keller  A. Nathues 《Icarus》2013

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Polarization Observation Experiments for Radio Flares of Stars at the 6 cm Band     

Bai Jian-yong  Han Jin-lin  Gao Xu-yang  Wang Chen  Zhang Li-yun 《Chinese Astronomy and Astrophysics》2013

We have performed radio polarization observation experiments of the stars V772 Her and β Per with the Urumqi 25 m radio telescope at the 6 cm waveband, and obtained light curves of the stars after data processing and calibration. A radio ?are from the star V772 Her was detected on 2011 April 13. The degree of linear polarization of this ?are is about 30%, and the polarization angle is about 4°. We have detected also the slowly-varying component of the radio radiation from β Per, as well as a short ?are superposed on it, which has a very weak linear polarization.  相似文献   

Distribution of Atmospheric Water Vapor Content over China     

Qian Xuan  Yao Yong-qiang  Li Jun-rong  Yin Jia  Zhang Yong-jing  Liu Li-yong  Wang Hong-shuai  Zhou Yun-he  Li Lin  You Xian-long  Ma Jiang-long 《Chinese Astronomy and Astrophysics》2013

Based on the data of 210 ground meteorological stations over China from 1961 to 2008, an empirical relation between the ground water vapor pressure and precipitation has been discovered. Then the equations used for estimating the ground water vapor pressure based on the precipitation are developed, and thereby to derive the atmospheric water vapor content, which is one of the important parameters for astronomical site survey. The results of this study show that in different seasons, there exists a stable correlative relation between ground water vapor pressure and precipitation, the water vapor pressures calculated from the precipitation data of different areas are consistent with the local practical measurements, and that the calculated atmospheric water vapor contents correspond well to the local long-term averages.  相似文献   

Rights-based management in Canada: Lessons from two coasts and a centre     

《Marine Policy》2014

Canada has had experience with a number of different rights-based management programs for fish harvesting for more than thirty years. These programs have spanned both coasts, as well as been applied to fisheries in the central region. This paper sets the institutional context within which these programs operate, reviews selected programs for instances of successes and/or failures, and presents some lessons learned.  相似文献   

Assessing the quality of data required to identify effective marine protected areas     

《Marine Policy》2014

This study aims to evaluate the effectiveness of currently available substrate data to designate marine reserves to meet conservation objectives. The case study site is Lyme Bay (approx. 2460 km²), in the western English Channel. An area of 240 km² in Lyme Bay was designated ‘closed to bottom dredging’ in July 2008 with the aim of protecting reefs which are an important habitat for Eunicella verrucosa (pink sea fan). The effects of using different substrate data resolution on the selection of sites to protect a range of biotopes using the Marxan package are determined. The effect of including a closed area on the efficiency of a marine reserve network is also investigated. Findings suggest that substrate data did not capture the biodiversity of the area and that using no data at all was equally effective. If low resolution data are all that are available then other options, such as expert opinion, or other data, such as activity use information could be used instead. Including a predefined closed area into the analysis led to an increase in area required to meet conservation goals using high resolution biotope data. It also increased the area of the reserve using the three substrate layers with no increase in protection for biotopes. This suggests that when designing networks of marine protected area sites, including current protected areas may be inefficient, resulting in larger areas being protected with no increased conservation of marine biodiversity. Policy makers must be prepared to adapt management in light of these findings and be aware of the shortcomings of the data available for use in marine conservation planning.  相似文献   

Enhancing the performance of quota managed fisheries using seasonality information: The case of the Portuguese artisanal dredge fleet     

《Marine Policy》2014

Several fisheries across the world are managed by a quota regime. These quotas can be set yearly, monthly, weekly or daily. However, for some fish species demand seasonality may occur, which should be taken into consideration in the establishment of the quota (especially in those fisheries managed by daily or monthly quotas). This would allow fishermen to catch more fish at times of the year with higher demand in detriment of periods when demand is low. The present work investigates the existence of demand seasonality for bivalves from the artisanal dredge fleet. This fleet operates along the entire coast of the Portugal mainland. The analysis of fleets' revenue efficiency is assessed with Data Envelopment Analysis models, and the monthly seasonality effects on the revenue efficiency were tested using a Tobit regression. The results revealed that on the South coast there is a strong demand in the summer whereas on the western coast (northwest and southwest fishing areas) demand increases during Christmas and New Year festivities. Since this fishery is managed by weekly/daily quotas, it is proposed that these quotas should be redistributed in order to adjust them to periods of higher demand, thereby increasing the profitability of the vessels. The approach followed could be applied to similar fisheries worldwide.  相似文献   

雷达径向风观测在华北区域数值预报系统中的实时三维变分同化应用试验   总被引：5，自引：1，他引：4  

陈敏  陈明轩  范水勇 《气象学报》2014,72(4):658-677

以实现业务应用为目标开展了区域多部雷达径向风观测资料的三维变分直接同化应用研究。重点对背景场误差协方差的方差和尺度因子进行调整,形成能够与其他常规观测资料协同同化的雷达径向风同化方案,并建立了京津冀6部多普勒雷达观测资料的实时预处理系统。基于上述工作开展2011年汛期京津冀多普勒雷达径向风观测资料在华北区域快速更新循环同化和预报系统中的实时同化和对比试验,并对应用效果进行了初步评估。实时同化试验期间京津冀地区6部雷达经过质量控制后的径向风数据质量和同化情况的分析结果表明,同化系统有效地吸收了雷达径向风的观测信息并形成合理的分析增量,其中,S波段雷达观测的径向风数据数量、质量和稳定度均明显优于C波段雷达;整体来看,雷达径向风同化对地面和高空要素预报性能的影响基本为中性,且主要影响时段集中在最初的6 h。但降水预报评分结果表明,雷达径向风同化从降水强度、落区和范围等方面均明显提升了系统对对流尺度降水的短时预报性能。同时也应该看到,受制于目前3 h一次的同化更新频率,雷达资料同化的效果往往到对流临近时次才能体现。  相似文献