近40 a石河子地区气候暖湿化特征分析     

范丽红  何清  崔彦军  潘晓玲 《干旱气象》2006,24(1):14-17,27

分析了40 a气温、降水及干旱指数的变化特征,结果表明:(1)近40 a石河子地区平均温度以0.3℃/10 a趋势上升,和全疆变化一致;该地区年、冬季、夏季气温总体呈上升趋势,20世纪60~70年代年、冬季、夏季气温呈降低的趋势,80~90年代气温呈增加趋势,80年代冬季升温比夏季升温明显,而90年代夏季升温比冬季明显。(2)降水总体趋势上升,降水增长率为12.5 mm/10 a,90年代平均降水比30 a均值偏多20.8%。(3)年平均干旱指数总体呈下降趋势,但趋势不明显,其减少率为-0.3/10 a。(4)石河子地区的温度、降水及干旱指数用M ann-kendall方法检验分别在不同年份发生了不同程度的突变。结果指出,石河子地区气候正在趋于暖、湿化,这对于本区绿洲的发展具有有利的一面。  相似文献   

太阳活动变化的小波分析   总被引：3，自引：0，他引：3  

郝立生  李新  李月英 《干旱气象》2006,24(4):15-19

结合太阳活动变化分析,介绍了Morlet小波变换方法在气象时间序列周期分析和突变分析中的应用,对太阳黑子活动得出了一些有意义的结果。分析发现,太阳活动存在14.5 a和106 a的变化周期,其中14.5 a周期最为显著。太阳活动强弱变化存在一定的阶段性,在近258 a发生过6次突变。  相似文献   

Numerical Simulation of Long-Term Climate Change in East Asia   总被引：1，自引：0，他引：1       下载免费PDF全文

TANG Jianping  SU Bingkai  ZHAO Ming  ZHAO Deming 《Acta Meteorologica Sinica》2006,20(1):50-61

A 10-yr regional climate simulation was performed using the fifth-generation PSU/NCAR Mesoscale Model Version 3 (MM5V3) driven by large-scale NCEP/NCAR reanalyses. Simulations of winter and summer mean regional climate features were examined against observations. The results showed that the model could well simulate the 10-yr winter and summer mean circulation, temperature, and moisture transport at middle and low levels. The simulated winter and summer mean sea level pressure agreed with the NCAR/NCEP reanalysis data. The model could well simulate the distribution and intensity of winter mean precipitation rates as well as the distribution of summer mean precipitation rates, but it overestimated the summer mean precipitation over North China. The model's ability to simulate the regional climate change in winter was superior to that in summer. In addition, the model could simulate the inter-annual variation of seasonal precipitation and surface air temperature. Geopotential heights and temperature at middle and high levels between simulations and observations exhibited high anomaly correlation coefficients. The model also showed large variability to simulate the regional climate change associated with the El Nino events. The MM5V3 well simulated the anomalies of summer mean precipitation in 1992 and 1995, while it demonstrated much less ability to simulate that in 1998. Generally speaking, the MM5V3 is capable of simulating the regional climate change, and could be used for long-term regional climate simulation.  相似文献   

CLIMATE CHANGE: LONG-TERM TRENDS AND SHORT-TERM OSCILLATIONS   总被引：2，自引：0，他引：2  

高新全  张欣  钱维宏 《热带气象学报(英文版)》2006,12(2):139-149

Identifying the Northern Hemisphere (NH) temperature reconstruction and instrumental data for the past 1000 years shows that climate change in the last millennium includes long-term trends and various oscillations. Two long-term trends and the quasi-70-year oscillation were detected in the global temperature series for the last 140 years and the NH millennium series. One important feature was emphasized that temperature decreases slowly but it increases rapidly based on the analysis of different series. Benefits can be obtained of climate change from understanding various long-term trends and oscillations. Millennial temperature proxies from the natural climate system and time series of nonlinear model system are used in understanding the natural climate change and recognizing potential benefits by using the method of wavelet transform analysis. The results from numerical modeling show that major oscillations contained in numerical solutions on the interdecadal timescale are consistent with that of natural proxies. It seems that these oscillations in the climate change are not directly linked with the solar radiation as an external forcing. This investigation may conclude that the climate variability at the interdecadal timescale strongly depends on the internal nonlinear effects in the climate system.  相似文献   

可数背景状态下QBD过程的平稳分布尾渐近态     

杨阳  赵以强  李刚 《南京气象学院学报》2006,29(2):235-241

考虑在可数背景状态下，时间离散的拟生灭过程（QBD过程）平稳分布的尾概率的渐近态。通过对QBD过程某些条件的限定，应用马尔可夫更新定理，得出在一定合理的条件下，当水平趋于无穷时的尾概率的几何衰变。通过初等方法，将该结论应用于时间离散的加入最短队模型。  相似文献   

基于RS对云南边境地区土地覆盖现状及变化研究   总被引：5，自引：2，他引：5  

刘美玲  齐清文  邹秀萍  李晋 《国土资源遥感》2006,17(1):75-78

 土地利用/覆盖变化研究是全球变化研究的热点之一。应用遥感、GIS技术及数理统计学的方法，利用1976年MSS和2004年TM二个时期的遥感影像数据，对云南边境地区的土地覆盖动态变化进行监测研究，并对变化的时空特征进行了分析。结果表明，土地覆盖现状以森林和裸岩地为主，土地利用/覆盖变化的主要方向是林地向裸地和耕地转化。  相似文献   

 RS和GIS支持下的盐池县生态景观格局动态变化研究   总被引：2，自引：1，他引：2  

张学俭  海云瑞 《国土资源遥感》2006,17(4):55-59

基于遥感（RS）和地理信息系统（GIS）技术，以Landsat TM/ETM图像为基本数据源，综合运用景观生态学理论和方法，对我国典型农牧交错生态脆弱区宁夏盐池县1991~2000年生态景观格局动态变化进行了研究。结果表明： 盐池县各景观类型都发生了很大程度的消长变化，景观格局处于快速调整和不稳定发展阶段，但生态景观基质还是草地，景观格局始终呈农牧交错结构。  相似文献   

四川水氡测值突跳异常与地震     

官致君 《四川地震》2006,(4):32-36

在四川开展水氡前兆观测的初期,部分水氡点的水氡测值突跳异常很好地对应了其可预测范围内的中强以上地震。水氡测值突跳异常曾作为松潘—平武和盐源—宁蒗等地震预报的重要依据。但在水氡观测至今的完整时间段内,水氡突跳异常总体表现出对应率低,漏报率高的现象。多次预报攻关研究结果显示,水氡观测的异常表现是多种多样的,水氡测值突跳异常只是其中的表现之一。在今后四川及邻区的中强以上地震预报实践中,水氡测值突跳异常仍可作为地震短临预报的重要参考。  相似文献   

Joint processing and analysis of seismic gravity measurements in Capital Circle area     

贾民育马丽  刘少明张晶孙少安  王武星 《地震学报(英文版)》2006,19(4):438-447

In Capital Circle area, there are three groups of repeated gravity measurements observed by different institutes using different instruments or methods. The simultaneous adjustment of absolute and relative measurements and the elimination of systematic error among the relative measurements have been carded out in this paper. Thus an unified temporal gravity change system with absolute reference has been established. On the basis of this, the crustal subsidence effect on gravity, which belongs to non-tectonic factor, is analyzed and the station displacement corrections are carried out, so that the long-wave disturbance is eliminated. So far our following aims are realized： the advantages of the absolute and relative measurement methods are complementary to each other; the contradiction and environment disturbance are eliminated; the amounts of information are enlarged; the sampling interval of time domain is compressed. In a word, the ability of identifying the tectonic activity process is enhanced. The results show that： there are systematic errors between the two groups of relative measurements and within the data of 10 campaigns ; the uneven local crustal subsidence in the southeast of the study area results in a linear rise of gravity value at 10 stations; they can be corrected by the regression analysis. The maps of revised temporal gravity change can obviously and integrally reflect the Ms=5.0 earthquake in Guye on October 6, 1995.  相似文献   

Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest   总被引：4，自引：0，他引：4  

ZHOU Guoyi  ZHOU Cunyu  LIU Shuguang  TANG Xuli  OUYANG Xuejun  ZHANG Deqiang  LIU Shizhong  LIU Juxiu  YAN Junhua  ZHOU Chuanyan  LUO Yan  GUAN Lili  LIU Yan 《中国科学D辑(英文版)》2006,49(3):311-321

The belowground part of terrestrial ecosystem is a huge carbon pool. It is believed that of the total 2500Gt carbon stored in global terrestrial ecosystem, soil carbon storage within the 1 m surface layer ac- counts for 2000Gt, which is 4-fold of vegetation car- bon storage[1,2]. Compared with the carbon in the vegetation, carbon in the deep soil layers is much more stable, and it will stay in soil profile permanentlyunless geological vicissitude occurs. Essentially, forest restoration is the…  相似文献