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241.
1. IntroductionAs well known, Kuroshio is a famous and strongwest boundary current in the North Pacific. It trans-fers enormous energy from the low latitudes to themid-high latitudes and releases huge heat flux to theatmosphere above (Hsiung, 1985). The variation ofKuroshio exerts great influence on weather and cli-mate in East Asian.During 1950-60s, Lü (1950, 1964) found that thewestern North Pacific SSTA had a close relation withsummer rainfall in China. In the 1970s, evidencesshowed… 相似文献
242.
根据NOAA/CPC发布的1950.1~2003.12期间Ni?o海区的SSTA资料,采用小波变换方法分析了SST变化的多时间尺度结构及其强度变化。结果表明,Ni?o各海区的SSTA序列表现出多层次相互嵌套的时频结构,经检验存在着2~7a、8~20a和30a以上尺度的变化周期;10a以上和1a以下时间尺度的周期信号能量较弱,显著性变化周期的能量主要集中在2~7a的周期振荡上;同一事件在不同海区的频率结构也不完全相同,冷暖事件的振荡能量和显著性水平从东向西有低频增大而高频减弱的变化趋势,时域中1970年以后尤为明显。 相似文献
243.
研究了定点连续形变长周期频段信息和块体构造活动的关系。研究结果表明,在川滇菱形块体内,定点连续形变观测获得的长周期频段信息中的长期趋势变化除去仪器零漂等局部干扰外,基本上都和块体运动方向或者块体边界主干断裂活动方式相一致,表明在定点连续形变长周期频段信息中,也存在有与地震孕育有关的地壳形变信息。对其在预报上的作用做了初步研究。 相似文献
244.
经中国地震局批准,由甘肃省地震局和西部各有关省、市、自治区地震局倡议发起,西部地区各级政府和防震减灾工作管理部门参加的“中国西部防震减灾论坛”今天在甘肃省酒泉市正式成立并举行首届大会,并将对西部防震减灾工作进行深入研讨。中国地震局刘玉辰副局长和中国工程院谢礼立院士等莅临指导,中国地震局有关部门和西部省、市地震部门领导及专家学者光临会议,这不仅是我省防震减灾工作的荣誉,而且也是西部地区防震减灾发展历史上的一大喜事。在此我代表甘肃省政府表示衷心的欢迎与祝贺。中国西部地区约占全国面积的三分之二,是我国强地震… 相似文献
245.
Introduction The research on the structure and physical property of ancient hidden hill, igneous rocks and basement is relatively difficult by using seismic data only. If we combine seismic data, magneto-telluric (MT) data and geophysical data together, better results can be obtained for the above problem. A number of geophysicists at home and abroad, such as CHEN and WANG (1990), Siri-punvarapor and Egbert (2000) have tried many methods to solve the problem by the inversion of seismic da… 相似文献
246.
Introduction Ready and Renkin (1971) were the first to make the research on anisotropy problems in magnetotellurics (MT). The progress in the research is not evident because it is more complex and difficult than isotropic problems. Now, the one-dimensional (1D) anisotropy problems in MT have been well solved, while for the two-dimensional (2D) cases, the numerical solutions have only been obtained for some particular conditions (Ready and Renkin, 1975). As to the three-dimensional (3D) ani… 相似文献
247.
ZHANG Renhua LI Zhaoliang SUN Xiaomin ZHU Zhilin & WANG Weimin Institute of Geographical Sciences Natural Resources Research Chinese Academy of Sciences Beijing China LSIIT 《中国科学D辑(英文版)》2005,(1)
This paper proposes a basic equation of thermal radiation interaction between surface objects on the basis of the principle of heat balance in the interface. The solution of this equation takes account of the contribution of sensible heat flux and latent heat flux more completely, compared with traditional solution for surface cooling and heating processes. By the aid of the experimental data conducted in the Xiaotangshan experimental site, Beijing, both the non-applicability of Kirchoff's law and the measurability of surface emissivity in a non-isothermal system have been highlighted. Two methods called ventilation and time-delay compensations have been proposed to reduce the error induced by change of surface temperatures of non-isothermal objects during the measurement of emissivity. Based on the solution of the basic equation, this paper has analyzed and pointed out the misunderstanding in comprehension and application of Kirchoff's law published in literature. 相似文献
248.
Although Eddy Covariance (EC) technique is one of the best methods for estimating the energy and mass exchanges between underlying surface and atmosphere in micrometeorology, errors and uncertainties still exist without necessary corrections. In this paper, we will focus on the effect of coordinate system on the eddy fluxes. Based on the data observed over four sites (one farmland site, one grassland site and two forest sites), the effects of three coordinate system transforming methods (Double Rotation-DR, Triple Rotation-TR and Planar Fit-PF)on the turbulent fluxes are analyzed. It shows that (i) the corrected fluxes are more or less than the uncorrected fluxes, which is related mainly to the sloping degree of surface, wind speed and wind direction; and (ii) pitch angle has a sinusoidal dependence on wind direction, especially in the regular sloping terrain; and (iii) PF method is something like the simplification of TR or DR,and there are not obvious distinctions in correction in sloping grassland and flat farmland, but PF method is not suitable for uneven and irregular forest sites. 相似文献
249.
SHA Liqing ZHENG Zheng TANG Jianwei Wang Yinghong ZHANG Yiping CAO Min WANG Rui Liu Guangren WANG Yuesi SUN Yang 《中国科学D辑(英文版)》2005,48(Z1)
With the static opaque chamber and gas chromatography technique, from January 2003 to January 2004 soil respiration was investigated in a tropical seasonal rain forest in Xishuangbanna, SW China. In this study three treatments were applied, each with three replicates: A (bare soil), B (soil+litter), and C (soil+litter+seedling). The results showed that soil respiration varied seasonally, low from December 2003 to February 2004, and high from June to July 2004. The annual average values of CO2 efflux from soil respiration differed among the treatments at 1% level, with the rank of C (14642 mgCO2· m-2. h-1)>B (12807 mgCO2· m-2. h-1)>A (9532 mgCO2· m-2. h-1). Diurnal variation in soil respiration was not apparent due to little diurnal temperate change in Xishuangbanna. There was a parabola relationship between soil respiration and soil moisture at 1% level. Soil respiration rates were higher when soil moisture ranged from 35% to 45%. There was an exponential relationship between soil respiration and soil temperature (at a depth of 5cm in mineral soil) at 1% level. The calculated Q1o values in this study,ranging from 2.03 to 2.36, were very near to those of tropical soil reported. The CO2 efflux in 2003was 5.34 kgCO2· m-2. a-1 from soil plus litter plus seedling, of them 3.48 kgCO2· m-2. a-1 from soil (accounting for 62.5%), 1.19 kgCO2· m-2. a-1 from litter (22.3%) and 0.67 kgCO2·m-2. a-1 from seedling (12.5%). 相似文献
250.