An Observed Connection Between Wintertime Temperature Anomalies over Northwest China and Weather Reg

来源 :Journal of Meteorological Research | 被引量 : 0次 | 上传用户:edwinandwolf
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
In this study, the association between wintertime temperature anomalies over Northwest China and the weather regime transitions in North Atlantic on synoptic scale is analyzed by using observational surface air temperature(SAT) data and atmospheric reanalysis data. Daily SAT anomaly and duration time are used in order to define SAT anomaly cases. Differences with regard to the circulation anomalies over the Ural Mountains and the upstream North Atlantic area are evident. It is found that the colder than normal SAT is caused by the enhanced Ural high and associated southward flow over Northwest China. Time-lagged composites reveal possible connections between the SAT anomalies and the different development phases of the North Atlantic Oscillation(NAO). The Ural highs tend to be strengthened during the negative phase of NAO(NAO–) to Atlantic ridge transition, which are closely related to the downstream-propagating Rossby wave activity. The opposite circulation patterns are observed in the warm SAT cases. A cyclonic circulation anomaly is distinctly enhanced over the Urals during the positive phase of NAO(NAO+) to Scandinavian blocking transition, which would cause warmer SAT over Northwest China. Further analyses suggest that the intensified zonal wind over North Atlantic would favor the NAO– to Atlantic ridge transition, while the weakened zonal wind may be responsible for the transition between NAO+ and Scandinavian blocking. In this study, the association between wintertime temperature anomalies over Northwest China and the weather regime transitions in North Atlantic on synoptic scale is analyzed by using observational surface air temperature (SAT) data and atmospheric reanalysis data. Daily SAT anomaly and duration time are used in order to define SAT anomaly cases. Differences with regard to the circulation anomalies over the Ural Mountains and the upstream North Atlantic area are evident. It is found that the colder than normal SAT is caused by the enhanced Ural high and associated southward flow through Northwest China Time-lagged composites reveal possible connections between the SAT anomalies and the different development phases of the North Atlantic Oscillation (NAO). The Ural highs tend to be strengthened during the negative phase of NAO (NAO-) to Atlantic ridge transition, which are closely related to the downstream-propagating Rossby wave activity the warm SAT cases. A cyclonic circulation anomaly is distinctly enhanced over the Urals during the positive phase of NAO (NAO +) to Scandinavian blocking transition, which would not warmer SAT over Northwest China. Further analyzes suggest that the intensified zonal wind over North Atlantic would favor the NAO- to Atlantic ridge transition, while the weakened zonal wind may be responsible for the transition between NAO + and Scandinavian blocking.
其他文献
我永远忘不了2014年5月3日那一天.rn上午妻子做好了父亲爱吃的核桃仁全麦面包,切好片,包好,准备下午我们去探望父亲时捎上.午饭刚过就接到父亲病危的电话,我急忙赶到医院,虽
黄河洪水时令名称的系统化,实际上是人们长期观测水情、预报水情的结果。黄河洪水时令称谓的源头可以追溯到先秦,到北宋时期日趋完整并系统化,明清以后形成了新的称谓体系,并与科技进步结合,形成黄河水情现代预报体系。  黄河洪水时令称谓  水情预报是防汛的耳目。我国的水情预报起源很早,先秦时期的《庄子·秋水》云“秋水时至,百川灌河”;《孟子·离娄下》云“七八月之间雨集,沟浍皆盈”,实指秋汛已至。到了西汉还有
期刊
特色是高校发展的核心竞争力,在专业建设中,特色也是立足之本。民族院校中的艺术专业有着其不可或缺的作用,承担着传承和发展少数民族文化艺术、培养少数民族艺术人才的主要
劳务输出直接影响农业剩余劳动力的多少,是制约我国农民收入增长和新农村建设进程的重大问题,对促进农村贫困地区快速发展具有重要意义.本文以山西贫困地区吕梁市为例,从劳务
农业灾害防治女性化问题,是指由于大量青壮年农民进程务工,农村留守妇女成为农业灾害防治的劳动力主体,从而给农业灾害防治、农村妇女身心健康和农业发展带来消极影响的问题.
四、关于理论和学术经典的阅读我在《文章五诀》中提出——形、事、情、理、典。这个“典”是指经典、典故,特别是理论经典。什么是经典?常说为经,常念为典。经典标准有三:一
中原岩画于20世纪80年代发现于禹州具茨山,后来逐步在河南郑州、许昌、驻马店、平顶山、南阳等地均有发现。其间,又有很多学者进行了艰苦的野外考察工作,目前已发现数千处岩画点分布。南阳周围浅山丘陵地区所发现的岩画,呈现出多元化特征。不仅圆凹穴岩画分布众多,棋盘纹样、生殖崇拜图腾、圆形祭坛、动物造型也随山就势雕刻于丘陵裸露的岩石上,构成了庞大的岩画系统。在南阳市皇路店镇柳树沟发现的蒸馍石生殖崇拜岩画,周
期刊
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
期刊
期刊
通过对实施案例剖析与归纳,提出我国农业标准化8大实施模式,并根据其联系分为5个时期和4个阶段,从而勾勒出中国农业标准化过程蓝图;得出该过程的发展,由社会责任引发,到利益