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1.
The antarctic sea ice was investigated upon five occasions between January 4 and February 15, 2003. The investigations included: (1) estimation of sea ice distribution by ship-based observations between the middle Weddell Sea and the Prydz Bay; (2) estimation of sea ice distribution by aerial photography in the Prydz Bay; (3) direct measurements of fast ice thickness and snow cover, as well as ice core sampling in Nella Fjord; (4) estimation of melting sea ice distribution near the Zhongshan Station; and (5) observation of sea ice early freeze near the Zhongshan Station. On average, sea ice covered 14.4% of the study area. The highest sea ice concentration (80%) was observed in the Weddell Sea. First-year ice was dominant (99.7%-99.8%). Sea ice distributions in the Prydz Bay were more variable due to complex inshore topography, proximity of the Larsemann Hills, and/or grounded icebergs. The average thickness of landfast ice in NeUa Fjord was 169.5 cm. Wind-blown snow redistribution plays an important role in affecting the ice thickness in Nella Fjord. Preliminary freezing of sea ice near the Zhongshan Station follows the first two phases of the pancake cycle.  相似文献   
2.
Profiles observed by Sea-Wing underwater gliders are widely applied in scientific research. However, the quality control(QC) of these data has received little attention. The mismatch between the temperature probe and conductivity cell response times generates erroneous salinities, especially across a strong thermocline. A sensor drift may occur owing to biofouling and biocide leakage into the conductivity cell when a glider has operated for several months. It is therefore critical to design a mature real-time QC procedure and develop a toolbox for the QC of Sea-Wing glider data. On the basis of temperature and salinity profiles observed by several Sea-Wing gliders each installed with a Sea-Bird Glider Payload CTD sensor, a real-time QC method including a thermal lag correction, Argo-equivalent real-time QC tests, and a simple post-processing procedure is proposed. The method can also be adopted for Petrel gliders.  相似文献   
3.
派比安台风对上海黄浦江潮位的影响及成因探讨   总被引:3,自引:3,他引:3  
徐建成 《海洋预报》2001,18(1):1-10
2000年派比安台风产生的历史第二高潮位对上海的防汛带来严重影响。本文通过比较历史上的风暴潮,从动力机制、天文高潮与增水极值相碰头,潮波共振和水利工程的影响等四个方面分析了这次风暴潮造成的高水位,及台风余振期边缘波的影响,并用SLOSH(Sea,Lake,Overland Surge from Hurricanes)模式模拟了这次风暴潮,为防台减灾的正确决策提供了理论依据。  相似文献   
4.
长江口海水的密度   总被引:1,自引:1,他引:1  
为了核对1980年国际海水状态方程应用于中国近岸海水的可靠性,高精度的磁力浮沉子密度计在15—25℃,盐度5—35,一个大气压条件下,测量了长江口附近海水及其人工稀释海水的相对密度。结果表明,海水密度直接测量值系统地偏高于状态方程计算值,二者之间的偏差随水样盐度值降低而增大,且与海水[Ca~(2+))/s比值成明显正相关关系。经计算机拟合,导出了长江口附近海水及其稀释海水的状态方程,该方程计算值与实验值的平均标准偏差为±3.9×10~(-3)kg/m~3。  相似文献   
5.
t Gravity anomalies on a2.5 ×2.5 arc-minute grid in a non-tidal system were derived over the South China and Philippine Seas from multi-satellite altimetry data. North and east components of deflections of the vertical were computed from altimeter-derived sea surface heights at crossover locations, and gridded onto a 2.5 × 2.5 arc-minute resolution grid. EGM96-derived components of deflections of the vertical and gravity anomalies gridded into 2.5 × 2.5 arc-minute resolutions were then used as reference global geopotential model quantities in a remove-restore procedure to implement the Inverse Vening Meinesz formula via the 1D-FFT technique to predict the gravity anomalies over the South China and Philippine Seas from the gridded altimeter-derived components of deflections of the vertical. Statistical comparisons between the altimeter-derived and the shipboard gravity anomalies showed that there is a root-mean-square agreement of 5.7 mgals between them.  相似文献   
6.
Given the second radial derivative Vrr(P) |δs of the Earth's gravitational potential V(P) on the surface δS corresponding to the satellite altitude, by using the fictitious compress recovery method, a fictitious regular harmonic field rrVrr(P)^* and a fictitious second radial gradient field V:(P) in the domain outside an inner sphere Ki can be determined, which coincides with the real field V(P) in the domain outside the Earth. Vrr^*(P)could be further expressed as a uniformly convergent expansion series in the domain outside the inner sphere, because rrV(P)^* could be expressed as a uniformly convergent spherical harmonic expansion series due to its regularity and harmony in that domain. In another aspect, the fictitious field V^*(P) defined in the domain outside the inner sphere, which coincides with the real field V(P) in the domain outside the Earth, could be also expressed as a spherical harmonic expansion series. Then, the harmonic coefficients contained in the series expressing V^*(P) can be determined, and consequently the real field V(P) is recovered. Preliminary simulation calculations show that the second radial gradient field Vrr(P) could be recovered based only on the second radial derivative V(P)|δs given on the satellite boundary. Concerning the final recovery of the potential field V(P) based only on the boundary value Vrr (P)|δs, the simulation tests are still in process.  相似文献   
7.
利用多个参考重力场模型分别对GRACE一个月的实测加速度计观测数据进行检校.数值计算结果的比较分析表明了利用参考重力场模型确定加速度计校准参数是有效的.  相似文献   
8.
极地冰雪氢氧同位素指标及其指示意义   总被引:1,自引:0,他引:1       下载免费PDF全文
本文综述了水汽来源状况、降水季节变化、火山喷发、太阳活动等气候环境因素对极地冰雪中同位素含量的可能影响及其程度 ,以及降水区域不均衡性、降水年际不均衡性、逆温层和同位素在冰雪中的扩散迁移作用等几种不稳定因素可能对冰雪同位素分析造成的干扰 ;在此基础上 ,综述了极地冰雪中δ1 8O、δD和其差值d(d =δD - 8δ1 8O)与局部或全球气温之间的一些线性关系 (包括全球尺度 ,格陵兰地区 ,南极地区等 )及它们在空间分布上的变化规律  相似文献   
9.
杨建成 《甘肃地质》1996,5(2):91-95
王家山煤矿断层密集,地裂缝发育,采空塌陷严重,这三者构成严重的地质灾害链。地裂缝的形成和发展,使矿区人民的生命财产遭受了惨重的损失。从工程地质及地质灾害的角度进行分析,认为新构造运动是动态的地质背景,黄土的特殊物理力学性质是静态的地质基础,人为的采空塌陷是地裂缝群产生的主要原因  相似文献   
10.
将一定范围内的地震数据假设为背景地震和丛集地震的叠加,并同时认为背景地震和丛集地震分别满足不同参数的二维泊松过程.通过引入N阶距离概念,将叠加的二维泊松过程转化为一维的混合密度函数,在对距离阶数进行选择的基础上,最终采用遗传算法进行混合密度分解,以达到提取地震丛集模式的效果.文中将该算法应用于我国西南地区松潘及龙陵主震前丛集地震的提取,并与C值的时间扫描结合,深化了这两次大地震前地震活动图象的认识.   相似文献   
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