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Both correlation analysis and case study indicate that Antarctic oscillation (AAO) is closely related with summer rainfall in eastern China. When AAO is stronger in boreal spring, especially in May, there is more mei-yu rainfall in summer with a longer period along the Yangtze and Huaihe River valley. In contrast, there is less rainfall with a shorter period corresponding to a weaker AAO. Besides, an anomalous AAO changes the position and intensity of several circulation systems, which are important to summer rainfall along the Yangtze and Huaihe River valley. Furthermore, the Antarctic sea ice is negatively correlated with the intensity of AAO with a 6-month leading time. The result in this study provides a new method for the prediction of mei-yu. 相似文献
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Fan （2007） recently documented the zonal asymmetry of the Antarctic oscillation （AAO） in the austral winter. In this research, the zonal asymmetry of the northern annular mode, or the Arctic oscillation （AO）, in the interannual variability is studied for the boreal winter. It is shown that there is zonal asymmetry of the AO as well, similar to the case of the Antarctic oscillation （AAO）. However, the zonal asymmetry of the AO is considerably weaker than that of the AAO. This is far beyond the speculation, since the zonal asymmetry of the geography is larger in the Northern Hemisphere than the Southern Hemisphere. The Western and Eastern Hemispheres portions of the AO are correlated at 0.54 for 1959-1998, comparing with 0.23 for the case of the AAO. The authors also discussed the physical reason for this inter-hemispheric difference, and partly attributed it to the El Ni~o and Southern Oscillation （ENSO） cycle which may be represented by the SO index. It is indicated that the SO associated sea-level pressure （SLP） patterns are more zonal symmetric in the high latitudes of the Northern Hemisphere than the Southern Hemisphere. 相似文献
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根据我国第22次南极科学考察现场观测数据以及现场采集的冰芯分析数据,考虑太阳辐射、云量等因素对南极海冰厚度变化的影响,利用最小二乘法辨识气温与冰表面温度之间的关系,并以辨识结果所得到的冰表面温度作为上边界条件,依据实测情况取结冰点-1．81℃作为下边界条件,对一维热传导方程采用Crank-Nicolson格式进行离散,对南极中山站内拉湾附近海域海冰厚度变化进行了数值模拟,并与现场观测的海冰厚度数据进行了对比。 相似文献
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目前,被动微波遥感数据已经成为提取极区海冰密集度的重要手段,其获取的海冰密集度产品不可避免的存在误差,这样的误差进而会引起南极海冰总覆盖范围和总覆盖面积的不确定性.利用蒙特卡洛方法对海冰密集度产品进行误差的模拟,对随机模拟影像进行统计分析,利用变异系数等指标量化随机误差带给南极海冰总覆盖范围和面积的不确定性.实验发现,当海冰密集度误差较小时,海冰覆盖范围的不确定性相比面积更大;当误差较大时,结论则相反.并且两者的不确定性都与分辨率和季节有关,分辨率越高,不确定性则越小,冬季比夏季的不确定性要小. 相似文献
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ENSO对东亚夏季风和我国夏季降水的影响研究进展 总被引：1，自引：0，他引：1
回顾了最近几年我国学者在ENSO对东亚夏季风和我国夏季降水影响方面的研究成果,通过夏季风时降水的影响分析ENSO对夏季降水的作用,结合1997-1998年的ENSO现象,对前人的理论和统计结果进行了讨论,指出除了ENSO发生的时间、区域、强度外,其增长和衰减率在这一问题的研究中也值得关注。 相似文献
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【目的】有效监测渤海辽东湾海冰状况,指导破冰船破冰,保障冬季冰期海洋石油平台的安全生产。【方法】在辽东湾石油平台上构建海冰测量系统,利用视频测冰技术、视频冰速测量技术及气象观测多种手段,在2011—2015年度连续4年冬季冰期观测平台周边海冰形貌、范围、运动轨迹,并对监测数据进行分析,给出24h海冰预报。【结果】基于海洋石油平台的海冰监测系统对海冰冰量、冰厚、冰速、冰类型监测数据准确,通过数据分析可以对海冰实施年、月、周、24h预报,短期预报与实际情况基本相符合,其中24h预报准确率在95%以上。【结论】基于海洋石油平台的海冰监测系统是一套运行可靠的监测系统,能准确地观测海冰的运行趋势,为冬季渤海辽东湾的抗冰活动提供指导。 相似文献
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航海雷达识别与跟踪海冰试验 总被引：11，自引：1，他引：11
在辽东湾某座石油平台上安装了监测海冰的航海雷达。首先对该雷达探测与识别海冰的效果进行了试验。结果表明,它可识别莲叶冰、平整冰、粗糙冰与冰脊,其识别能力主要与雷达性能、天线高度以及海冰表面粗度有关;为了增大雷达对海冰的探测距离,在平台顶部架设了天线塔,使天线高度达到５５ｍ;该雷达系统有对海冰连续跟踪的能力,可为研究海冰生消和运动规律提供依据,同时也是局部海冰实时监测与海冰管理的有力手段。 相似文献
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Relationship between the Antarctic oscillation in the western North Pacific typhoon frequency 总被引：1，自引：0，他引：1
WANG HuiJun FAN Ke 《科学通报(英文版)》2007,52(4):561-565
Relationship between the Antarctic oscillation (AAO) and the western North Pacific typhoon number (WNPTN) in the interannual variability is examined in this research. The WNPTN is correlated with the AAO in June-July-August-September (JJAS) in 1949-1998 at -0.48 for the detrended time series, statistically significant at 99% level. The tropical atmospheric circulation as well as the sea surface temperature variability over the western Pacific associated with AAO has been analyzed. It follows that a positive phase of JJAS AAO corresponds to the larger magnitude of the vertical zonal wind shear, the anomalous low-lever anticyclonic circulation and anomalous high-level cyclonic circulation, and lower sea surface temperature in the major typhoon genesis region in the western North Pacific, thus providing unfavorable environment for the typhoon genesis, and vice versa. 相似文献
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The rotation of the earth, including the variation of the rotational rate and polar motion, represents the statement of the earth’s overall movement and interactions among the solid earth, atmosphere and ocean on a variety of space-time scales. They make the earth’s complex dynamical system under the conservation of angular momentum. The application and development of recent space geodetic techniques greatly promote the researches on the interactions between the earth rotation and the activities of atmosphere and ocean. This review will mainly report the progress in researches on the earth rotation and the activities of atmosphere and ocean as well as the air-sea interaction in the tropics, and prospect the direction for future theoretical investigations. 相似文献
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Based on the NCEP/NCAR reanalysis data set, empirical orthogonal function analysis and wrrelation analysis have been carried out. Antarctic osillation index (AOI) is defined as the difference between the zonal-mean monthly sea level pressure departures of 40°s and 65°s. Regional surface temperature and precipitation over the extratropical Southern Hemisphere have a close relationship with AO1. 相似文献
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电阻率冰厚监测装置在南极海冰考察中的应用 总被引：2，自引：0，他引：2
电阻率冰厚监测装置是中国第21次南极考察中海冰厚度监测的技术设备之一。结合南极极端环境,对基于冰、水不同电传导性质的电阻率冰厚监测装置首次在南极海冰考察中所取得的数据进行了分析,总结出极地海冰不稳定的现场环境和低温是影响该装置测量精度的主要因素,并依据分析结果对该装置提出了改进措施。 相似文献
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从提高资源利用和生产效率的角度,比较,分析了河北省在环渤海地区的海洋资源现状、海洋资源与海洋产业的匹配情况,揭示出河北省在海洋资源开发和经济发展中的优势与问题。 相似文献
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Cases of the interdecadal variability in the Pacific Ocean and their evolution were examined in the paper with the statistic methods (CEOF and composite analysis) over the period of 1950–1993. Observations of oceanic temperatures in the upper 400 m revealed an obvious region of the interdecadal signals in the central North Pacific. Such signals propagated southwestward, then subducted to the subtropics. The hypothesized link for interdecadal oceanic variability between the subtropics and the tropics, especially with the western tropical Pacific was unraveled in order to detect the cause of decadal signals in the tropics. The thermal anomalies subducted in the central North Pacific east to the dateline only reach 18°N. There has been no further southward propagation since then due to a certain barrier. The origin of the interdecadal signals in the western tropical Pacific was traced to the southern tropical Pacific. There is a meridional pathway around the dateline where the signals were loaded. These variabilities were in the nature of the thermocline circulation. 相似文献
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LIAO Dechun ZHOU Yonghong & LIAO Xinhao Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China National Astronomical Observatories Chinese Academy of Sciences Beijing China United Center for As-tro-Geodynamics Research Chinese Academy of Sciences Shanghai China Correspondence should be addressed to Liao Dechun 《科学通报(英文版)》2003,(16)
El Ni駉 is a kind of the disastrous events occurring in the central and eastern parts of tropical Pacific. It pre-sents itself as anomaly of sea surface temperature (SST) in these parts of the tropical Pacific. It is called an El Ni駉 (La Ni馻) event whenever the tropical Pacific SST anom-aly is warmer (cooler) than 0.5℃(- 0.5℃) and lasts for over 6 months[1]. Southern oscillation (SO) is a seesaw- like variation of sea level pressure (SLP) in eastern and western parts of the souther… 相似文献
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Xueyuan Tang Zhanhai Zhang Bo Sun Yuansheng Li Na Li Wang Bangbing Xiangpei Zhang 《自然科学进展(英文版)》2008,18(2):173-180
The 3-dimensional finite difference thermodynamic coupled model on Antarctic ice sheet, GLIMMER model, is described. An idealized ice sheet numerical test was conducted under the EISMINT-1 benchmark, and the characteristic curves of ice sheets under steady state were obtained. Based on this, this model was simplified from a 3-dimensional one to 2-dimensional one. Improvement of the difference method and coordinate system was proposed. Evolution of the 2-dimensional ice flow was simulated under coupled temperature field conditions. The results showed that the characteristic curves deriving from the conservation of the mass, momentum and energy agree with the results of ice sheet profile simulated with GLIMMER model and with the theoretical results. The application prospect of the simplified 2-dimensional ice flow model to simulate the relation of age-depth-accumulation in Dome A region was discussed. 相似文献