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1.
1982—1983年冬季东亚气候距平的主要特征是有三个距平带和热干、冷湿两种距平状态。作者发现,在厄尼诺现象盛行时,副高明显加强,这是15°N 以南出现热干气候的直接原因。我国新疆地区偏暖,华南、西南地区偏冷也同厄尼诺有一定的遥相关关系。15°—30°N 的强大降水正距平则同东亚南支急流加强和南移有密切关系,南支急流加强则是其南侧的副高加强和其北侧青藏高原气温的强大负距平与雪盖扩大的结果。从降水带与高空急流的关系看,该冬季15°—30°N 地带的降水增多是一种季风雨的加强,同夏季梅雨加强的环流特点是相同的。  相似文献   

2.
初值协调性对模式数值积分结果的影响   总被引:2,自引:1,他引:1  
利用国家气候中心新一代全球大气环流模式BCC_AGCM2.0.1,考虑了初值协调性对模式数值积分结果的影响,进行了两组数值回报试验(简称S1,S2),对27年(1980~2006年)的夏季基本气候态进行了对比分析,并考察了该模式对夏季气候的回报技巧。使用交叉检验的方法,计算了对模式结果的评估参数值,包括时间和空间距平相关系数,对该模式性能进行了评估和检验。结果表明,BCC_AGCM2.0.1对季节尺度的大气环流场具有良好的模拟性能,模式基本上再现了观测位势高度场、温度场、流场的分布特征以及大尺度降水分布特征。500 hPa位势高度、温度空间距平相关系数对比表明,平均而言,500 hPa位势高度、温度的空间距平相关性,热带区域(30°S~30°N)高于东亚区域(0°~60°N,60°E~150°E)和全球区域。回报与观测的降水距平百分率相关系数分布对比表明,试验S2在我国江淮地区及南方地区的回报技巧要明显优于S1。  相似文献   

3.
柴达木盆地气候变化对荒漠化的影响   总被引:4,自引:0,他引:4  
利用累积距平等方法对柴达木盆地近46 a(1961~2006年)气温、降水资料进行了分析,探讨了柴达木盆地气候变化对荒漠化的影响。结果显示:柴达木盆地气候变暖趋势明显,土地沙漠化面积扩大、植被退化、覆盖率减少和盐渍化程度加重。气候变暖、多大风、蒸发强是影响该区土地荒漠化的主要自然原因之一。  相似文献   

4.
基于MDERF(Monthly Dynamic Extension Range Forecast)模式输出500hPa位势高度场资料和贵州各月干旱综合指数、降水和气温等历史样本,利用秩序回归降尺度法,研究该方法对贵州月干旱综合指数、降水和气温的预报技巧和预测效果.结果表明:该方法从穷尽所有因子组合中选出彼此独立的3个最佳组合因子共同作为预报因子,从而增强可预报性;模型5 a回报试验和2007年8月试报结果表明该方法在实际预测业务中的应用潜力;各气候要素多年的距平相关系数评分比较稳定,其中月干旱综合指数、降水距平百分率、气温距平全年平均距平相关系数评分分别为0.14、0.15和0.14;各气候要素中月气温预报的Pc最高,平均为73%.综合分析表明,该方法在月动力延伸预报产品对贵州月气候要素预测释用中具有较好的应用前景.  相似文献   

5.
自贡市近50年来气候变化特征分析   总被引:1,自引:0,他引:1  
本文利用自贡市1955~2006年的气温、降水资料,采用线性倾向估计、累计距平、Mann-Kendall等方法,研究了自贡市近52年来气温、降水的年、季变化特征.结果表明:在全球气候变化背景下,近52年来,自贡年平均气温略上升,年降水量略减少.秋季气候表现为明显的暖干趋势,春季气候则具有明显的变湿趋势.近10年来自贡气候变暖趋势明显.  相似文献   

6.
近100年来中东亚干旱区气候异常与海平面气压异常的关系   总被引:2,自引:2,他引:0  
利用中东亚干旱区近100年(1901-2002年)降水、气温及北半球海平面气压的格点资料,分析了该干旱区冬季、夏季降水和气温与海平面气压分布形势的相关关系,同时对典型的降水和气温异常年份的海平面气压距平场进行了合成分析.结果表明:冬季西北太平洋海平面气压持续增强、阿拉伯海附近维持较高气压时,中东亚干旱区冬季降水偏多、气温偏高.前期春季海平面气压的变化对中东亚干旱区夏季降水有显著的影响,当春季阿留申低压和其南部的西太平洋副热带高压偏强时,中东亚干旱区夏季降水偏多;当春季西太平洋副热带高压位置附近的海平面气压偏高时,中东亚干旱区夏季气温偏低;前期春季海平面气压的异常对中东亚干旱区气候变化的显著影响,对气候预测有很好的指示意义.另外,中东亚干旱区冬季异常多雨、高温年份,海平面气压在中高纬度地区为负距平,在低纬度地区则为正距平.而冬季异常少雨、低温年份,气压场分布的主要特征则相反.在夏季异常多雨年,中东亚干旱区主要位于正的气压距平区,夏季异常少雨年则反之.夏季异常气温偏高年,正距平区主要分布在印度半岛北部,中东亚干旱区西部处于负距平区、东部处于弱的正距平区中.分析结果同时说明了中东亚干旱区易出现冬季多雨/高温(少雨/低温)和夏季多雨/低温(少雨/高温)的气候配置.  相似文献   

7.
中国气候变化指数分析   总被引:2,自引:0,他引:2  
用统计学方法对全国范围内160个测站1951-1996年的46年内气温、降水资料进行分析,得出年平均气温、降水的标准化距平场以及冷、暖季的气温、降水的标准化距平场,干旱指数等一系列表征气候变化的指标,以这些指标为基础得出气候增暖作用指数和气候极值性指数,并得出气候变化趋势是向着干和热的方向发展变化的。  相似文献   

8.
近50年华北干旱的年代际和年际变化及大气环流特征   总被引:59,自引:11,他引:59       下载免费PDF全文
利用1948~2000年NCEP/NCAR再分析逐日及月平均位势高度、风、温度、垂直速度等物理量和中国气温、降水资料,分析近50年中国华北地区干旱的年代际、年际变化及其环流特征,并探讨1999和2000年华北地区持续干旱环流型及其成因.研究指出:20世纪80年代以来华北地区降水持续偏少,干旱强度有所增加,这与夏季200 hPa矢量风距平场亚洲中纬度西风环流加强,850 hPa风矢量距平场中国东部110~120°E范围内偏南气流比气候平均状况偏弱有关.夏季华北降水偏少的一种主要大气环流型是:500hPa位势高度场上40~50°N的欧亚大陆位势高度偏高并叠加欧亚(EU)遥相关型,华北大部分地区受高压控制.1999和2000年夏华北地区持续严重干旱的主要环流特征是:亚洲大陆高压持续发展、长期维持并相当稳定,华北地区上空受闭合暖性高压控制,高空暖性高压气流强烈下沉,引起空气绝热增温,近地面感热增加使得干旱区气温升高,下垫面非绝热强迫作用与大陆暖高压加强形成正反馈过程.  相似文献   

9.
本文考虑到气候变暖的影响,以降水量、平均气温和降水日数作为地区干旱强度的物理量,设计根据降水量距平百分率、气温距平、降水日数距平和影响权重系数的干旱强度评估方法,并利用VB6.0编译语言制作应用系统。  相似文献   

10.
利用美国NCEP/NCAR提供的再分析资料和全国160个站逐日降水量资料,按照东亚夏季副热带季风定义和东亚夏季副热带季风活动路径划分标准,选取3类路径的东亚夏季副热带季风各9个典型年,分析5月下旬—6月下旬合成的大气环流演变过程与同期降水距平分布,尝试揭示东亚初夏副热带季风的纬向差异特征.结果表明:3类活动路径东亚夏季副热带季风在850 hPa风场、500 hPa高度和降水距平分布差异显著.偏西路径表现为波列偏西偏北,850 hPa的南风正距平始终位于中国西南地区上空,降水正距平也集中于该区;中间路径代表气候态,为东亚地区初夏副热带季风的主要模态,大槽位置偏东,降水正距平主要分布在我国华南地区;偏东路径在120°E—180°E和20°N—70°N的区域呈现北负南正的波列,初夏副热带季风活动偏于西太平洋地区,我国东南部沿海与台湾的降水为正异常.2010年以来,东亚—西北太平洋地区初夏均为非中间路径副热带季风,3类路径的3—5月北太平洋海表温度距平分布差异也较大.  相似文献   

11.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.  相似文献   

12.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.  相似文献   

13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region.  相似文献   

14.
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.  相似文献   

15.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.  相似文献   

16.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.  相似文献   

17.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.  相似文献   

18.
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on  相似文献   

19.
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration.  相似文献   

20.
The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o.  相似文献   

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