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1.
夏季北半球500hPa月平均场遥相关型及其与我国季风降水异常的关系 总被引：9，自引：0，他引：9
用一点相关法计算了盛夏北半球５００ｈＰａ遥相关型，得到７月份北半球存在７个遥相关型，８月份有６个遥相关型。研究了它们的中心，计算了各遥相关型的历年强度指数（１９５１－１９９０），研究了它们的年际变化、月际变化。指出７月份的东亚太平洋型、北美东西遥相关型；８月份的ＥＡＰ型、欧亚型与我国盛夏季风降水关系密切。１９９１年夏季发生的弱ＥＡＰ型是江淮流域大涝的一个重要原因。 相似文献
2.
北半球４月５００ｈＰａ平均场遥相关型与我省秋季降水异常的关系及其物理机制初探韩照宇（山西省气象科学研究所０３０００２）提要本文从春季４月北半球５００ｈＰａ月平均高度场存在的５个遥相关型［１］出发，计算了１９５１～１９９０年各遥相关型的逐年强度指数，研... 相似文献
3.
本文从春季４月北半球５００ｈＰａ月平均高度场存在的５个遥相关型出发，计算了１９５１－１９９０年各遥相关型的逐年强度指数，研究了强度指数与我省交年秋季降水的关系，并地其物理机制作了初步探讨。结果表明，４月５００ｈＰａ的西太平洋型（ＷＰ）、太平洋北美型（ＰＮＡ）的强弱，与我省次年秋季大范围旱涝关系密切，而且物理机制较为清楚。 相似文献
4.
利用１９５１～１９９６年的历史资料,逐月计算北半球５个主要遥相关型的波列指数及与大气中ＰＮＡ结构相类似的北太平洋海温场的ＰＴＩ指数,进而对１～２月份青岛市冬季的月平均气温进行相关普查。计算表明,两大洋东侧的遥相关结构和波型,对来年青岛市冬季１～２月份气温有比较好的指示意义：５月份太平洋东侧的ＰＮＡ型结构（ＰＴＩ指数）与来年１月青岛市平均气温呈同向相关,７月份大西洋东侧的ＥＡ型波列指数与来年２月青岛市平均气温呈反向相关。 相似文献
5.
北半球早春30hPa遥相关型特征,起因及其与赤道海温异常 总被引：2，自引：0，他引：2
根据１９５８￣１９９１年资料，用一点相关法得到了３、４月北半球３０ｈＰａ月平均高度场遥相关型，研究了它们的指数特征、起因及其与后期赤道东太平洋厄尔尼诺事件的联系。 相似文献
6.
北半球冬季遥相关型环流异常的若干性质 总被引：3，自引：0，他引：3
用１９５１－１９８５年间北半球冬季７００，５００，１００ｈＰａ月平均位势高度场，分析了Ｗａｌｌａｃｅ等提出的５个遥相关型所对应的环流异常和它们的性质，发现它们在对流层中下部是相当正压结构，在对流层上部减弱消失，某些遥相关型（如ＥＵ，ＰＮＡ）环流异常存在明显；主要遥相关型环流异常的持续时间约为一个月。 相似文献
7.
500hPa高度场遥相关型与广东降水的关系 总被引：2，自引：0，他引：2
应用1956－2000年资料，从500hPa高度场上的相关性出发，找出了北半球（4－6月）的高度场上遥相关型，计算了它们的强度指数并分析了各遥相关型与广东降水的相关尤其是与中山市降水的关系，发现4月北太平洋型和6月北大西洋型及西大西洋型遥相关型与广东尤其是中山的降水有密切关系，而6月的西大西洋遥相关型对广东降水有很好的预测作用。 相似文献
8.
利用已定义的遥相关强度指数公式,分别计算了１９５１－１９９５年北半球５００ｈＰａ夏季和冬季（１２、１、２月）的遥相关强度指数,同时计算了湖北省１０个代表站温度距平、降水距平百分率与各遥相关型的相关系数。结果表明,对湖北省温度有影响的遥相关型主要有１２月的ＥＵＰ指数、７月的ＮＡＥＷ指数;对湖北省降水有影响的遥相关型主要有冬季的ＰＮＡ、ＥＵＰ指数等。 相似文献
9.
冬、夏季青藏高原地面加热场激发的500hPa遥相关型 总被引：3，自引：0，他引：3
本文用青藏高原地面加热场强度来表征高原的加热状况，并用统计的方法，分析了冬季（２月）和夏季（７月）青藏高原地面加热场强度与同期５００ｈＰａ位势高度的遥相关关系，得到如下结论：冬季高原地面加热场可激发北半球５００ｈＰａ产生遥相关型，这种遥相关型可看成是二维Ｒｏｓｓｂｙ波列由低纬向东北方向传播；夏季高原地面加热场可激发北半球５００ｈＰａ产生类似于ＥＵ型的遥相关，这种遥相关型可看成二维Ｒｏｓｓｂｙ波列由 相似文献
10.
利用１９８０年１月～１９８３年１２月已滤波的ＯＬＲ资料，采用经验正交函数分析方法，对１９８０～１９８１年（正常年）和１９８２～１９８３年（异常年）低纬西太平洋和印度洋地区低频振荡的空间分布及遥相关特征进行了研究．结果表明：正常年与异常年，这些地区低频振荡的强度、空间型及时间系数的变化有较大的差异．此外，还发现正常年这些地区存在３种低频遥相关，即赤道西太平洋型，北热带西太平洋型和赤道印度洋型；异常年则仅存在２种低频遥相关，即赤道西太平洋型和南热带西太平洋型．由于受厄尔尼诺事件的影响，东西向偶极型低频振荡中心的位置和强度都有很大的变化 相似文献
11.
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 Nio3.4 index in summer and autumn but negatively correlated in spring and winter. 相似文献
12.
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
13.
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(Stl), 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
14.
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
15.
Fei LIU Chen XING Jinbao LI Bin WANG Jing CHAI Chaochao GAO Gang HUANG Jian LIU Deliang CHEN 《大气科学进展》2020,37(7):663-670
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
16.
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
17.
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
18.
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
19.
Yuepeng PAN Mengna GU Yuexin HE Dianming WU Chunyan LIU Linlin SONG Shili TIAN Xuemei Lü Yang SUN Tao SONG Wendell W. WALTERS Xuejun LIU Nicholas A. MARTIN Qianqian ZHANG Yunting FANG Valerio FERRACCI Yuesi WANG 《大气科学进展》2020,37(9):933-938
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
20.