共查询到20条相似文献，搜索用时 93 毫秒
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Jianping LI Tiejun XIE Xinxin TANG Hao WANG Cheng SUN Juan FENG Fei ZHENG Ruiqiang DING 《大气科学进展》2022,39(4):625-642
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
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Xiangdong ZHANG Yunfei FU Zhe HAN James E.OVERLAND Annette RINKE Han TANG Timo VIHMA Muyin WANG 《大气科学进展》2022,39(4):553-565
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
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QIN Xiao-Hao 《大气和海洋科学快报》2010,3(3):170-175
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
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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
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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
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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
智协飞 《南京气象学院学报》2007,30(6):885-889
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
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我国近30年龙卷风研究进展 总被引：5，自引：3，他引：2
从3方面总结了龙卷风研究成果:①研究概况,最初的龙卷风灾后调查到开展天气气候特征分析至近年来开展龙卷风本体结构、产生机制的探讨,获得了丰硕成果;②研究方法提高,从事实调查到利用统计方法,从利用台站常规观测资料到运用卫星、多普勒雷达、风廓线仪等非常规资料开展分析,近年数值模式WRF、ARPS等也被用来研究龙卷风,研究的方法手段不断得到改进;③龙卷风研究、预报面临的困难和未来展望。 相似文献
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为研究干旱农业区农耕季节气溶胶的基本光学特性,2014年4月利用地面气溶胶移动集成系统在甘肃武威黄羊镇农场开展气溶胶综合观测试验。结果表明,河西走廊黄羊镇农场PM2.5和PM1.0的散射系数以及PM2.5的吸收系数分别为98.2±38.3、74.6±29和8.8±6.3 Mm-1,均小于中东部地区观测值。气溶胶单次散射反照率为0.90±0.03,PM2.5和PM1.0的Angstrom指数分别为1.31±0.29和2.10±0.24。散射系数和吸收系数的日变化具有明显的双峰特征,单次散射反照率在散射系数出现峰值的时间段出现谷值。黄羊镇农场受人为气溶胶影响较大,西、西南和东南方向来的气溶胶散射系数和吸收系数值较大,西北方向传输过来的气溶胶主要是农业生产活动产生的。 相似文献
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城市气象研究进展 总被引：5，自引：0，他引：5
中国数十年来在城市气象研究这一新兴学科领域开展了大量研究并获得了多方面的丰硕成果。文中从城市气象观测网与观测试验、城市气象多尺度模式、城市气象与大气环境相互影响、城市化对天气气候的影响等4个方面论述了城市气象的主要研究进展:中国各大城市已建立或正在完善具有多平台、多变量、多尺度、多重链接、多功能等特点的城市气象综合观测网;北京、南京、上海等地开展了大型城市气象观测科学试验,被世界气象组织列入研究示范项目;成功开展了风洞实验、缩尺度外场实验研究;建立了多尺度城市气象和空气质量预报数值模式,并应用于业务;在城市热岛效应、城市对降水影响、城市气象与城市规划、城市化对区域气候及空气质量的影响、城市气象与大气环境相互作用等研究领域取得长足进展。最后指出,未来需要重点从新观测技术及观测资料同化应用、城市系统模式研究、城市化对天气气候的影响机理、城市化对大气环境和人体健康的影响、城市水文气象气候与环境综合服务等方面开展科学研究与应用,为中国城市化、生态文明建设、防灾减灾和应对气候变化等国家需求提供科技支撑。 相似文献
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根据武汉市1951—2007年间年平均、最高、最低气温与8类年极端天气日数的序列,计算分析其变化趋势及年平均气温与极端天气日数的相关性,引入格兰杰因果性检验法,探讨气候变暖与极端天气事件之间的因果关系。结果发现:(1)近57年来武汉市年平均最低气温增幅为0.45℃/10a,明显高于年平均最高气温0.19℃/10a的增幅,可见气候变暖主要是由夜间气温升高所致;(2)高温和闷热天气事件为增多趋势,其中闷热天气事件最明显,达到2.8 d/10a,而年雷暴、降雪、低温、大风、雾日则均为下降趋势,雷暴、雾和低温事件降幅明显,每10年减少3.0 d、4.0 d和2.1 d。大风和降雪事件,每10年减少1.8 d和1.5 d。暴雨事件波动幅度较小。(3)年平均气温与当年及超前、滞后1～2年的极端天气事件具有高相关性;(4)格兰杰因果性检验结果发现,气候变暖是闷热天气增多和降雪事件减少的原因,同时亦是大风和低温减少的结果。这种因果关系的存在对极端天气事件预测和预估有重要的价值。 相似文献
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Eiichi Inoue 《Boundary-Layer Meteorology》1974,7(3):257-266
A brief review of the research activities of Japanese scientists in aerobiology, which is one of the interdisciplinary sciences closely related to atmospheric turbulence and diffusion as well as to biology, is presented in order to make contacts with interested scientists in other countries. 相似文献
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A preliminary investigation of monthly rainfall patterns analysed from 24‐hour computer forecasts of precipitation was performed. These patterns are compared with the observed precipitation and long‐term normal patterns. Recommendations are made to incorporate the method into a verification program for the computer product. 相似文献
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《高原山地气象研究》2022,(Z1)
利用NECP再分析资料和地面降水资料,对凉山州2020年9月10～17日连阴雨过程进行诊断分析。结果表明：此次连阴雨过程从低层到高层影响系统稳定;孟加拉湾的西南气流带来持续的水汽输送和能量补充,同时强降水区也有明显的水汽辐合中心;中层显著的上升运动为强降水的发生提供了持久的动力支持;低层持续的冷平流为冷暖气流的交汇提供了有利的条件,冷暖气团交汇的能量锋区对于降水强弱分界有很好的指示意义。 相似文献