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1.
In this paper,we investigate the influence of the winter NAO on the multidecadal variability of winter East Asian surface air temperature(EASAT)and EASAT decadal prediction.The observational analysis shows that the winter EASAT and East Asian minimum SAT(EAmSAT)display strong in-phase fluctuations and a significant 60-80-year multidecadal variability,apart from a long-term warming trend.The winter EASAT experienced a decreasing trend in the last two decades,which is consistent with the occurrence of extremely cold events in East Asia winters in recent years.The winter NAO leads the detrended winter EASAT by 12-18 years with the greatest significant positive correlation at the lead time of 15 years.Further analysis shows that ENSO may affect winter EASAT interannual variability,but does not affect the robust lead relationship between the winter NAO and EASAT.We present the coupled oceanic-atmospheric bridge(COAB)mechanism of the NAO influences on winter EASAT multidecadal variability through its accumulated delayed effect of~15 years on the Atlantic Multidecadal Oscillation(AMO)and Africa-Asia multidecadal teleconnection(AAMT)pattern.An NAO-based linear model for predicting winter decadal EASAT is constructed on the principle of the COAB mechanism,with good hindcast performance.The winter EASAT for 2020-34 is predicted to keep on fluctuating downward until~2025,implying a high probability of occurrence of extremely cold events in coming winters in East Asia,followed by a sudden turn towards sharp warming.The predicted 2020/21 winter EASAT is almost the same as the 2019/20 winter.  相似文献   

2.
Three striking and impactful extreme cold weather events successively occurred across East Asia and North America during the mid-winter of 2020/21.These events open a new window to detect possible underlying physical processes.The analysis here indicates that the occurrences of the three events resulted from integrated effects of a concurrence of anomalous thermal conditions in three oceans and interactive Arctic-lower latitude atmospheric circulation processes,which were linked and influenced by one major sudden stratospheric warming(SSW).The North Atlantic warm blob initiated an increased poleward transient eddy heat flux,reducing the Barents-Kara seas sea ice over a warmed ocean and disrupting the stratospheric polar vortex(SPV)to induce the major SSW.The Rossby wave trains excited by the North Atlantic warm blob and the tropical Pacific La Nina interacted with the Arctic tropospheric circulation anomalies or the tropospheric polar vortex to provide dynamic settings,steering cold polar air outbreaks.The long memory of the retreated sea ice with the underlying warm ocean and the amplified tropospheric blocking highs from the midlatitudes to the Arctic intermittently fueled the increased transient eddy heat flux to sustain the SSW over a long time period.The displaced or split SPV centers associated with the SSW played crucial roles in substantially intensifying the tropospheric circulation anomalies and moving the jet stream to the far south to cause cold air outbreaks to a rarely observed extreme state.The results have significant implications for increasing prediction skill and improving policy decision making to enhance resilience in“One Health,One Future”.  相似文献   

3.
1引言伊春自动气象站是国家基本站(现改为一级站),每天担负8次天气报,资料参加全球交换。当计算机出现故障时,天气报是否能在规定的时间内准确的编发出是至关重要的。出现故障时,在短时间内准确的手工编发出报文难度很大,容易出现错情或造成迟报等重大错情。为了避免这种情况的发生,总结了以下几种方法进行编发报,降低了出错的几率。  相似文献   

4.
In this paper, several sets of observing system simulation experiments (OSSEs) were designed for three typhoon cases to determine whether or not the additional observation data in the sensitive regions identified by conditional nonlinear optimal perturbations (CNOPs) could improve the short-range forecast of typhoons. The results show that the CNOPs capture the sensitive regions for typhoon forecasts, which implies that conducting additional observation in these specific regions and eliminating initial errors could reduce forecast errors. It is inferred from the results that dropping sondes in the CNOP sensitive regions could lead to improvements in typhoon forecasts.  相似文献   

5.
秋天     
风就那么轻轻地扇了一下,整个荒原就着了火,不停奔忙的救火人却面带微笑。站在垄上,我的心在随着他们的韵律激动地博跳。金黄色玉米,黄金样水稻,所有的稼禾都积极地  相似文献   

6.
7.
精细农业研究进展   总被引:2,自引:2,他引:2  
精细农业是随着全球定位系统、遥感技术和农业新技术、地理信息系统、计算机技术的发展而兴起的现代农业管理方法,它将给农业生产带来深刻的变革.从农业资源的利用现状出发,分析了精细农业概念产生的必然性及其核心指导思想,并阐述了精细农业的技术组成、形成过程、国内外现状、发展趋势和成功应用.  相似文献   

8.
With temperatures increasing as a result of global warming,extreme high temperatures are becoming more intense and more frequent on larger scale during summer in China.In recent years,a variety of researches have examined the high temperature distribution in China.However,it hardly considers the variation of temperature data and systems when defining the threshold of extreme high temperature.In order to discern the spatio-temporal distribution of extreme heat in China,we examined the daily maximum temperature data of 83 observation stations in China from 1950 to 2008.The objective of this study was to understand the distribution characteristics of extreme high temperature events defined by Detrended Fluctuation Analysis(DFA).The statistical methods of Permutation Entropy(PE)were also used in this study to analyze the temporal distribution.The results showed that the frequency of extreme high temperature events in China presented 3 periods of 7,10—13 and 16—20 years,respectively.The abrupt changes generally happened in the 1960s,the end of 1970s and early 1980s.It was also found that the maximum frequency occurred in the early 1950s,and the frequency decreased sharply until the late 1980s when an evidently increasing trend emerged.Furthermore,the annual averaged frequency of extreme high temperature events reveals a decreasing-increasing-decreasing trend from southwest to northeast China,but an increasing-decreasing trend from southeast to northwest China.And the frequency was higher in southern region than that in northern region.Besides,the maximum and minimum of frequencies were relatively concentrated spatially.Our results also shed light on the reasons for the periods and abrupt changes of the frequency of extreme high temperature events in China.  相似文献   

9.
王蔚  江小雪 《黑龙江气象》2007,(1):34-34,36
1引言在自动站投入使用前绝大多数气象站使用的是EL型风向风速计,其瞬间风速是通过风速指示计人工测得的,人为因素大,精度不够,但人工测量给大风重要天气报、大风危险和解除报提供了依据,不会出现大风记录和报文之间的矛盾现象,而自动站的大风记录却不一样,其记录的大风的起止时间,极大风速及出现的时间是非常精确的,要求值班员实时注意查看自动站的大风记录,避免漏报、错报。由于自动站采集控制软件SAWSS在处理大风记录时存在不足,当大风达到不同的发报标准时不能及时报警,以提醒值班人员作出相应的处理,所以极易造成过时报,甚至漏报。  相似文献   

10.
气象水文灾害的防灾减灾教育培训新进展   总被引:1,自引:0,他引:1  
简要综述了第十届世界气象组织教育与培训大会的主题报告内容.本次大会主要讨论防灾减灾的气象水文教育与培训等问题,集中讨论了"备灾-预防和早期预警"、"减灾-应急、救援和重建"和"跨学科培训"等3个主题,强调集合数值预报系统对于估计出现极端天气事件的风险非常重要,同时必须培训气象、水文工作者使用集合预报中的概率预报信息.中国气象灾害监测、预测和预警已经从单纯提供一般意义上的气象灾害信息提升到有利于社会经济发展的气象灾害服务,既考虑自然因子也考虑经济发展的影响.在跨学科培训方面,将管理知识和气象知识结合起来,可以取得非常好的效果.大会建议提高世界气象组织区域培训中心以及各国气象水文部门培训单位的培训能力,主要通过提供防灾减灾的专门培训单元,对自然灾害风险管理短期课程进行指导,重视各国气象水文部门对于管理和传播领域培训的需求.  相似文献   

11.
康志明 《气象》2002,28(8):58-61
今年 5月 ,与常年同期相比 ,除东北大部、华北北部、华南东部、内蒙古东部和南疆大部等地降水明显偏少外 ,我国其余大部地区降水偏多或接近常年。本月全国大部地区气温接近常年或偏低 ,其中黄淮西部、江淮大部、西南地区东部、湖北和湖南北部等地的气温偏低 1~ 2℃ ,东北和华南东部沿海偏高 1~ 2℃。本月有一个热带风暴生成。1 天气概况5月份降水量 ,西南东部地区、黄淮大部及其以南地区在 10 0mm以上 ,其中江南及重庆大部、贵州大部、云南西南部、广西、广东中部等地一般有 2 0 0~ 330mm ,局部地区达 330~ 4 70mm ;东北、华北、…  相似文献   

12.
鲁中山区东北部丘陵地区霜冻特征分析   总被引:1,自引:0,他引:1  
利用临朐县1980-2008年29年间作物生育季节3—11月的所有“黑、白”霜观测记录,对鲁中山区东北部丘陵地区霜冻进行统计分析。结果表明,鲁中山区东北部丘陵地区霜冻有明显的地域特征,即霜冻危害较重的季节在3—4月份;霜冻类型以辐射霜冻为主;霜冻发生的气候特征与当地地形地貌密切相关;从而为鲁中山区东北部丘陵地区霜冻的预测预报提供可靠的依据。  相似文献   

13.
本文利用常规资料及数值预报产品,对2014年12月1日牡丹江出现的暴雪天气过程进行诊断分析,结果表明:高空阶梯槽的形成和维持,为暴雪提供了有利的环流背景,中低空切变线和低压倒槽是主要影响系统,为暴雪产生提供强的辐合上升运动和水汽条件;冷平流的持续使近地面气温降至0℃以下,保证了降雪所需要的温度条件。  相似文献   

14.
Fluctuations in the length of the growing season in Minnesota   总被引:3,自引:0,他引:3  
Fluctuations in growing season length and in the dates of the last spring freeze and first fall freeze between 1899 and 1982 were studied for five rural Minnesota stations with long, high quality records. A general increase in growing season length was found, but there was substantial variation in the pattern of fluctuations among the stations. The increase in growing season length is not clearly and uniformly related to changes in the dates of first and last freezes. The interannual variability of growing season duration is on the order of the increase in duration so that the change would not be readily apparent to a casual observer. Our results do not correspond well with certain other studies of growing season length nor with fluctuations in hemispheric mean temperature. We conclude that extreme care must be used in extrapolating results of growing season length studies in space and in relating them to mean temperature fluctuations.  相似文献   

15.
主要用洛阳15 年冬季能见度资料对比,提出1994 年11 月—12 月出现多日大雾天气在历史上是少见的。通过分析1994 年几例典型大雾形成的具体特点和影响因素及天气形势。指出稳定层的存在,适宜的地面气压场是导致大雾的直接原因  相似文献   

16.
2002年夏季山东干旱成因分析   总被引:11,自引:4,他引:11  
顾润源  汤子东 《气象》2004,30(8):22-26
分析了山东省 2 0 0 2年夏季降水、气温特点和干旱情况 ,并从大气环流、北太平洋SST、气候背景等方面对少雨干旱气候的影响进行了分析 ,指出冬季大气环流、北太平洋SST对山东夏季旱涝趋势的预测具有重要的指示意义。  相似文献   

17.
Summary From a study of five cases of pronounced fronts in the upper troposphere, it is concluded that the waterspout model offers the most satisfactory solution to the problem of connecting frontal boundaries and tropopauses. Composite cross sections of temperature, potential temperature, normal wind component and potential vorticity are presented for the five cases. On the basis of the potential vorticity measurements it is suggested that the most likely explanation for the formation of the high-level front is a folding of the tropopause.
Zusammenfassung Auf Grund einer Untersuchung von fünf Fällen ausgesprochener Fronten in der höheren Troposphäre wird der Schluß gezogen, daß die Wasserhosen-Vorstellung am besten den Zusammenhang zwischen Fronten und Tropopausen darstellt. Kombinierte Querschnitte von Temperatur, potentieller Temperatur, normaler Windkomponente und potentieller Vorticity werden für die fünf Fälle vorgelegt. Auf Grund der Bestimmungen der potentiellen Vorticity wird dargelegt, daß die wahrscheinlichste Erklärung für die Entstehung einer Front in der Höhe in der Annahme einer Faltung der Tropopause besteht.

Résumé En se fondant sur cinq cas de fronts très nets de la haute troposphère, les auteurs concluent que le schéma de trombe constitue la meilleure solution pour représenter la liaison entre zones frontales et tropopause. Ils donnent des profils combinés de température, de température potentielle, de composantes normales du vent et de vorticity potentielle pour les cinq cas. Ils montrent à l'aide de mesures de la vorticity potentielle que l'explication la plus probable de la formation d'un front en altitude consiste à admettre un plissement de la tropopause.


With 11 Figures

Contribution No. 37, Department of Meteorology and Climatology. —The research reported in this article has been supported by the Geophysical Research Directorate, Air Force Cambridge Research Center, under Contract No. AF 19 (604)-1811.  相似文献   

18.
主要用洛阳15年冬季能见度资料对比,提出1994年11月-12月出现多日大雾天气在历史上是少见的.通过分析1994年几例典型大雾形成的具体特点和影响因素及天气形势.指出稳定层的存在,适宜的地面气压场是导致大雾的直接原因.  相似文献   

19.
Presented are the results of mercury content measurements in the surface air layer in the Sea of Japan in the period from October 27 to November 11, 2010. It is revealed that the mercury content varied from 0.6 to 3.8 ng/m3. It is demonstrated that the mercury concentration distribution has geographical zoning and depends on the movement of air masses and on the closeness of anthropogenic sources. The maximum mercury concentration is detected in the central part of the sea at the southwestern and southern directions of the wind, that is associated with the industrial emissions of East Asia countries. The minimum mercury concentration corresponding to the concentration in the surface air layer of the Arctic, Atlantic Ocean (Northern Hemisphere), and the Sea of Okhotsk and Bering Sea was observed along the coast of Primorye at the northwestern wind direction.  相似文献   

20.
1998年洞庭湖流域特大暴雨的雨水情分析   总被引:2,自引:1,他引:1  
潘志祥  宁迈进 《气象》1999,25(9):11-14
应用1998 年汛期湖南省97 个气象站、200 多个水文站的雨量、水文资料,分析了同期洞庭湖流域特大暴雨洪涝的雨水情概况和基本特征。  相似文献   

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