Influence of the NAO on Wintertime Surface Air Temperature over East Asia: Multidecadal Variability and Decadal Prediction

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.     

Extreme Cold Events from East Asia to North America in Winter 2020/21: Comparisons,Causes, and Future Implications

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”.     

自动气象站出现故障编发报文的几种方法

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。     

The Sensitive Regions Identified by CNOPs of Three Typhoon Events

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.     

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     

精细农业研究进展

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.     

INVESTIGATION OF THE SPATIAL AND TEMPORAL DISTRIBUTION OF EXTREME HIGH TEMPERATURE IN CHINA WITH DETRENDED FLUCTUATION AND PERMUTATION ENTROPY

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.     

自动站大风报警程序设计

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。     

气象水文灾害的防灾减灾教育培训新进展

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.     

广西春夏季旱涝的等级划分及时空分布特征分析

利用广西80多个站点1961～2006年的逐月降水资料,采用Z指数定义方法,对广西春夏季的旱涝进行等级划分.利用经验正交函数(EOF)分析方法对春夏季旱涝等级的时空分布进行研究,给出了四个旱涝典型场的分布特征.分析结果表明:全区性偏涝或偏旱是春夏季早涝分布的最主要型态;春季和夏季的前4种分布形态都通过了显著性检验,两个季度的第一、第二分布形态都是全区一致型和南北反向型;春季近5年时间系数多为正值,说明近年来全区春季表现为偏旱;1990年以后,夏季第一特征向量时间系数只有3年为正值,其余均为负值,说明近16年广西夏季降水较多,以偏涝为主,年代际变化也较明显.     

Interannual and Interdecadal Variations in Atmospheric Circulation Factors and Rainfall in China and Their Relationship

Wavelet analysis is used to study the interannual and interdecadal variations of rainfall in China and atmospheric circulation factors, including the key atmospheric oscillations, W, C, E patterns and subtropical high. Regression analysis and correlation analysis are both used to study the relationship of atmospheric circulation factors and China rainfall on different time scale and spatial scale. The results are as follows: (1) The variations of atmospheric circulation and rainfall in China are characterized by interannual and interdecadal scales. The variations of atmospheric circulation and rainfall are composed of interannual and interdecadal variations. It is necessary to separate those two time scales when climate changes and forecast are studied. (2) The variations of China rainfall are due to the interaction of multi-factors rather than single factors. The marked factors which influence the interannual and interdecadal variations are various. Subtropical high is one of the marked factors which influence interannual variations of rainfall, while AO, NAO, and NPO are one of the marked factors which influence interdecadal variations of rainfall. (3) The longer the time scale is, and the larger the spatial scale is, and the more remarkable the relationships between atmospheric circulation and rainfall are.     

亚洲区域海—陆—气相互作用对全球和亚洲气候变化的作用研究进展

围绕全球变化研究国家重大研究计划项目“亚洲区域海—陆—气相互作用机理及其在全球变化中的作用”预定的总体研究内容和科学目标,项目执行两年多以来,取得了一系列阶段性科研成果.关于气候动力学方面,项目揭示了热带印度洋—西太平洋暖池的海温变化是全球热带气候年代际变化的重要驱动力,是全球尺度副热带干旱的重要调控器;发现热带东太平洋海温存在冷舌模态,它是一个海气耦合模态,阐明在全球变暖背景下其对ENSO型态变异的作用及影响东亚气候的机理;揭示了青藏高原热力强迫的异常特征及其气候效应;提出了水平非均匀基流中行星波传播的理论,研究了其在不同东亚夏季风背景下的传播特征.关于气候预测方法方面,提出了若干有物理基础的气候预测方法,如尺度分离的降尺度预测新方法、基于北大西洋涛动(NAO)-ENSO的东亚夏季风预测模型、基于南半球环状模的东亚气候预测模型等,为业务部门提供了重要参考.关于观测方面,项目在亚洲区域海气补充观测和海洋资料同化方面也取得突出进展,成功进行了南海18°N断面海洋综合观测,为形成我国第一条南海断面长期海气观测打下了基础.在国际合作方面,项目还继续推动和领导了“亚洲季风年”(AMY2007-2012)与“东亚气候模拟”国际计划,提升了我国在该领域的国际地位.     

湖南主汛期旱涝与大气环流及春季海温的关系

利用1960-2006年NCEP/NCAR逐月再分析资料、NOAA月平均海表温度资料和湖南月降水资料等,在计算分析湖南主汛期旱涝变化特征的基础上,对湖南主汛期旱涝大气环流及其与春季海温的关系进行了分析。结果表明,湖南主汛期洪涝指数增大趋势显著,1990年代以来处于洪涝多发期。洪涝指数具有20年、9年和3~4年的周期;干旱指数存在22年、10年和2~4年周期。湖南主汛期旱涝与西太平洋副热带高压、中高纬度环流、南亚高压、低层流场、水汽输送等持续异常有关。当西太平洋副热带高压面积偏大,强度偏强,脊线偏南,西伸脊点偏西,鄂霍次克海地区多阻塞活动,南亚高压主体位置较常年偏西,来自南海的水汽输送较常年强,低层湖南大部分地区处于辐合气流控制之下,湖南主汛期易洪涝;反之,当西太平洋副热带高压面积偏小,强度偏弱,脊线偏北,西伸脊点偏东,鄂霍次克海地区少阻塞活动,南亚高压主体位置较常年偏东,来自南海的水汽输送较常年弱,低层湖南大部分地区为辐散气流控制,湖南主汛期易干旱。春季印度洋、赤道中东太平洋和黑潮海温是湖南主汛期旱涝变化的重要短期气候预测信号,春季印度洋和赤道中东太平洋海温偏高(低)有利于湖南主汛期降水偏多(少),黑潮海温偏低湖南主汛期易少雨干旱。     

Wildfire Occurrence in Siberia and Seasonal Variations in Heat and Moisture Supply

Subregional occurrence of fires in Siberian forests and seasonal variations in heat and moisture supply are analyzed. Instrumental data on wildfires registered through satellite monitoring data for the period of 1996–2016 are used. The dynamics of the weather fire danger index (PV-1) and intraseasonal anomalies of the Selyaninov’s hydrothermal coefficient (HTC) defining fire occurrence variation are revealed using meteorological data series for the Siberian subregions. The statistical regularities of the dynamics of the weather fire danger index are summarized for subregions. The separated scenarios are formalized by model functions. The projections of the probability of the scenarios’ implementation, the fire return period, and the respective relative burned area are determined.     

开封、洛阳市近47a气温降水变化异同分析

利用开封、洛阳市1961-2007年气温、降水气象要素资料,采用数理统计原理,对两市的气温、降水变化及两市气温、降水变化的异同进行了分析,结果表明:两市47 a平均气温都呈明显波动上升趋势,气温逐年变化较大,开封市的年平均气温及变化幅度高于洛阳市;春秋冬各季的平均气温都呈明显的上升趋势,开封市上升幅度略高于洛阳市;夏季平均气温都呈下降的趋势,洛阳市下降的幅度比开封市明显.降水量开封市比洛阳市偏多,开封市呈上升的趋势,洛阳市呈下降的趋势,两市春秋两季平均降水量都呈下降趋势,洛阳市比开封市下降明显;夏冬两季平均降水量都呈上升趋势,开封市上升幅度高于洛阳市.     

四川地区云和空中水资源分布与演变

利用1971～2000年台站云降水资料和NCEP再分析资料,分析了四川地区云和空中水资源的分布与演变。研究发现:四川地区平均总云量为7.2成,低云量4.7成,全年阴天日数193.5天,降水日数154.0天,小到中雨日147.1天;全年大气可降水量为181.7kg.m-2。云有明显的季节变化特征,总云量夏季最高,春季次之,冬季最低,低云量夏季最高,秋季次之,冬季最低。大气可降水量夏季最大,秋季次之,冬季最少。云和小到中雨日的空间分布具有明显的地域性,且夏季分布与全年分布显著不同。在高原上,总云和低云、降水日、小到中雨日呈相反的变化趋势,总云在平均状态附近波动略有减少,而低云、降水日、小到中雨日在平均状态附近波动略有增加;在盆地内,云和降水日的演变趋势相同,总云量、低云量、降水日、小到中雨日都在线性减少。30年来四川地区大气可降水量线性变化则略有增多。     

Changes in integral and aerosol atmospheric turbidity in Trans-Baikal and Central Siberia

The analysis of time series of the Linke turbidity factors is performed for the atmosphere mass m = 2 (T ₂) and atmospheric aerosol optical thickness for the wavelength λ₀ = 0.55 μm (AOT) from the data of 14 actinometrical stations of Central Siberia and Trans-Baikal territory. It is shown that over the period from 1976 to 2006, the increased atmospheric transparency is observed in the region. Quantitative estimates of changes in multiyear mean annual variations of T ₂ and AOT at different periods of averaging and for different time periods are derived.     

2009年夏季铜仁地区高温干旱的诊断分析

2009-07—09铜仁地区出现了大范围持续性的高温干旱天气,给铜仁地区农业生产和人民生活带来较大的影响。该文对此次高温干旱的成因从环流形势、物理量场进行诊断分析。     

近年来云降水物理和人工影响天气研究进展

回顾和总结了中国科学院大气物理研究所近5年(2003～2007年)的云降水物理和人工影响天气研究,内容涉及云和降水物理研究、云和降水数值模拟研究、人工影响天气研究和云化学研究等诸多领域。随着国家和社会对人工影响天气需求的日益增加,云降水物理仍是重要的研究方向,会随着观测和理论研究的发展而取得突破性进展。