阳江地区逐时气温和降水特征分析

利用2005-2011年阳江站和阳春站的气温、降水的逐时资料进行分析,探讨阳江地区不同季节、不同天气条件下的气候特征.结果表明：（1）春天气温日较差最大,盛夏最小;最低气温除了盛夏其余都是晴天时最低,夏季夜间气温大小和变化都比较接近;白天秋冬春季晴天时气温接近或低于多云时的气温;阳春的对比差距相对要大些,最高气温出现时间随季节的变化和天气状况的变化相差很大.（2）前汛期降雨概率大于后汛期,6月为降水主峰期,后汛期则以8月降雨最为频繁.阳江站前汛期降雨有两个频密时段分别在早晨和傍晚,阳春站午后降雨最频繁,并呈现中心向两边递减态势.短时强降水阳江概率分布与出现降雨的分布很相似,阳春站短时强降雨则分为早晨到上午和午后两个集中阶段.     

阳春站气象观测环境变化对观测资料的影响

对阳春气象站搬站前后的日平均温度、最高气温、最低气温、风向风速、相对湿度等数据进行对比分析,得出阳春市气象观测站迁站前后气象要素差异的基本规律,并从中分析环境变化对气象观测资料的影响.     

长清国家一般气象站迁移对比观测资料差异分析

通过采用差值的方法,对长清国家一般气象站迁站后新、旧两站对比观测期间的温度、湿度、风向风速观测数据进行对比分析,发现两个测站在不同的月份存在不同的差异。7月新站日平均气温、日最高最低气温和10月最高气温偏低、10月新站日平均气温、日最低气温偏高,1月的日平均气温、日最高气温、日最低气温新站高于旧站并且占绝大多数;日平均相对湿度是7月偏大、10月相同、1月偏小。新站日平均风速明显大于旧站。     

大通县一般站迁站对比观测数据的差异分析

利用大通站新址与旧址2017年1—12月同期实测到的气象资料,采用统计分析方法分析大通站迁站前后气温、湿度、风等要素;用U检验法对气象观测站迁站前后资料是否有明显差异进行检验。得出:(1)全年平均气温新址比旧址偏低0.2℃,平均最高、最低均偏低分别为0.7℃、1.6℃。冬季和春季为负温差,夏季和秋季基本为正温差,且温度越低负温差越大,温度越高正温差也越大;全年的月平均风速新址均高于旧址,全年月平均差值分布没有一定的规律性,冬季和夏季两站的月平均风速相差明显比其它季节大;全年相对湿度除6、7、9月新址小于旧址外,其余各月均新址大于旧址。(2)从U检验结果看,除了10、12月最低气温外,其他气象要素在迁站前后无显著差异。在使用气象资料时,新旧站址资料能够合并统计。     

贵州2008年与2022年年初低温雨雪冻雨天气过程对比分析

利用常规气象观测资料以及NCEP再分析资料,通过对实况资料、环流背景、气候背景的研究,对2008年和2022年年初贵州省低温雨雪冻雨天气过程进行对比分析。结果表明：2022年冷空气强度与2008年相比偏弱,最低气温比2008年偏高2.7 ℃;日平均降雪站数接近2008年略偏少,达到了2008年的91%;日平均冻雨站数与2008年相比明显偏少,仅达到2008年的29%,2022年最大雪深超过了2008年。两次低温雨雪天气的成因共同点是：拉尼娜事件的影响;副高、欧亚阻高异常偏强以及中亚、西亚低值系统活跃,持续大量暖湿空气向北输送水汽;不同点是：2022年鄂霍次克海低涡强度偏弱。在两次低温雨雪持续期间,副高异常增强、北抬,欧亚阻高形势稳固,北极明显升温,持续的水汽输送和逆温存在,为这两次雨雪冰冻灾害提供重要的环流背景。     

昌吉站迁站对温压降水要素的影响和分析

选择2008年昌吉新老两站址一年的气温、气压、降水量日值的366个对比观测数值（降水量214个数值）,使用U和F检验对两地迁站前后日资料的均值和方差进行检验,发现最低、最高、平均气压和最低气温资料在0.05的显著水平下,由于迁站使前后资料的平均值出现比较显著的差异;方差除了降水量序列外,其他要素均在0.05的显著水平下存在显著性差异;将各要素的数据标准化后进行交叉对比,发现新旧站气压数据之间的变化频率和浮动都比较一致,标准化曲线基本重合,而气温数据尤其是最低气温,两站标准化曲线存在较大的差异;通过累积距平处理,发现新老站的变化趋势基本相同,只是新站序列图形的变化浮动较老站略大。     

探测环境对北京气象站气温观测值的影响分析

为深入了解气象探测环境对气温观测数据的影响,利用2017年北京市观象台（54511）与南海子站（A1274）逐小时地面气象要素数据,分析两站气温差异以及因站点探测环境导致的日照、风速和降水对两站气温差异的影响。结果表明：2017年两站气温差异较明显,年平均气温54511站比A1274站高0.75℃;两站逐月平均气温54511站全年高于A1274站,两站差值7月最低为0.60℃,9月最高为1.09℃;两站平均日最高气温较接近,平均日最低气温差异较大,54511站较A1274站高1.24℃;两站气温的日变化特征相似,呈单峰分布,54511站气温日较差低于A1274站。两站小时气温差值随着日照时长和强度的增加而增加,短波辐射效应最强的10-14时和长波辐射效应最强的19-23时两站气温差值与当日白天直接辐射曝辐量的相关系数分别为0.459和0.601;水平风速对两站气温差值的影响较大。水平风速超过5 m·s^-1时,两站气温差小于0.1℃;当水平风速不超过1 m·s^-1时,两站观测气温差值达到1.28℃;降水天气下两站的气温差值小于非降水天气,出现降水时次54511站平均气温仅比A1274站高0.2℃。两站相距4.3 km,气候均一,测站周边2 km范围内建设用地占比54511站比A1274站高约30%,植被占比低28%,水体占比相差不大。另外,54511站附近的五环路具有低反射率和高热容的特征,白天能够吸收太阳辐射储存较多的热量,这些热量在夜间释放,可能是两站探测环境对太阳辐射吸收的差异决定了两站温差受太阳辐射和风速的影响较大,而受降水影响较小。     

昌吉站迁站对温压降水要素影响的分析

选择2008年昌吉新老站址一年的气温、气压、降水量日值的366个对比观测数值(降水量214个数值),使用U和F检验对迁站前后日资料的均值和方差进行检验,发现最低、最高、平均气压和最低气温资料在0.05的显著水平下,由于迁站使前后资料的平均值出现比较显著的差异;方差除了降水量序列外,其他要素均在0.05的显著水平下存在显著性差异;将各要素的数据标准化后进行交叉对比,发现新旧站气压数据之间的变化频率和浮动都比较一致,标准化曲线基本重合,而气温数据尤其是最低气温,两站标准化曲线存在较大的差异;通过累积距平处理,发现新老站的变化趋势基本相同,只是新站序列图形的变化浮动较老站略大。     

新疆吐鲁番市1952～2012年气温变化特征及城市化影响

利用吐鲁番气象站1952 ～2012 年逐月平均气温和平均最高、最低气温,逐日最高、最低气温以及高温、低温日数资料,采用线性回归、9 a 滑动平均方法,研究吐鲁番市近61 a 气温变化趋势,对比了吐鲁番东坎农试站1981 ～2012 年逐月平均最高、最低气温资料,分析近32 a 城市化进程对吐鲁番市气温的影响.结果表明：吐鲁番市除夏季平均气温、冬季极端最高气温呈下降趋势外,其余均呈不同程度上升趋势,其中尤以冬季极端最低气温和平均最低气温增加最为显著,且气温增加趋势夏季均低于冬季;高温日以1. 3 d/10 a 速率增加,而低温日以4. 8 d/10 a 速率减少;城市化进程对温度的影响具有季节变化和日变化特点.冬季温度差大于其他季节,最低温度温差明显大于最高温度温差.     

气象站迁站距离及海拔高差对新旧站资料差异的影响分析

本文采用新疆13个已迁站新旧站1年对比观测资料,分别计算新旧站资料的绝对差值及差值标准差与迁徙距离和海拔高差的相关系数,分析迁站距离和海拔高差对新旧站资料差异的影响结果表明,年平均气温、最低气温、最高气温、相对湿度新旧站绝对差值和标准差与台站迁徙距离和新旧站海拔高差为正相关,新旧站年风向相符率与台站迁徙距离和海拔高差为负相关;其中,迁站距离对最高气温和风向相符率影响最为显著,最高气温的年值绝对差值及年风向相符率与台站迁徙距离相关系数通过了保证率为95%的显著性检验;而台站迁徙前后海拔高差对平均气温、最低气温、相对湿度影响更为显著,即新旧站平均气温、最低气温、相对湿度的年值绝对差值与新旧站海拔高差的相关系数通过了保证率为95%的显著性检验。山区由于地形复杂年平均气温、年最低气温、年相对湿度的绝对差值比多数平原站大一倍以上,且风向相符率都比平原站小一个量级;在极其干旱的东疆吐鲁番地区迁站,由于地表环境差距较大,使年平均气温、最低气温、相对湿度绝对差值和标准差比其它站大,而风向相符率都比其它站小。     

加强业务管理提高测报质量

我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格.     

Quantifying the uncertainty of the annular mode time scale and the role of the stratosphere

The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998–2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features.     

由中国历史气候记录对季风导致唐朝灭亡说的质疑

2007年1月4日杂志发表了Yancheva等10人的题为"Influence of the intertropical convergence zone on the East-Asian monsoon"(热带辐合带对东亚季风的影响)的论文[1],这是德国波兹坦地学研究中心气候动力与沉积学科的主管豪格(G.H.Haug)率领的科研小组的一项成果,认为是季风的变化引起的长期干旱导致了唐朝的灭亡.     

On the forecast of the onset and end of the convective season in the Amazon

Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature (SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds. Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early) onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with respect to its mean date in most of El Ni?o cases. The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region. The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully predicted, and there were no predictions of categories opposed to those observed. Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002     

Comparing the theoretical versions of the Beaufort scale, the T-Scale and the Fujita scale

2005 is the bicentenary of the Beaufort Scale and its wind-speed codes: the marine version in 1805 and the land version later. In the 1920s when anemometers had come into general use, the Beaufort Scale was quantified by a formula based on experiment. In the early 1970s two tornado wind-speed scales were proposed: (1) an International T-Scale based on the Beaufort Scale; and (2) Fujita's damage scale developed for North America. The International Beaufort Scale and the T-Scale share a common root in having an integral theoretical relationship with an established scientific basis, whereas Fujita's Scale introduces criteria that make its intensities non-integral with Beaufort. Forces on the T-Scale, where T stands for Tornado force, span the range 0 to 10 which is highly useful world wide. The shorter range of Fujita's Scale (0 to 5) is acceptable for American use but less convenient elsewhere. To illustrate the simplicity of the decimal T-Scale, mean hurricane wind speed of Beaufort 12 is T2 on the T-Scale but F1.121 on the F-Scale; while a tornado wind speed of T9 (= B26) becomes F4.761. However, the three wind scales can be uni-fied by either making F-Scale numbers exactly half the magnitude of T-Scale numbers [i.e. F′half = T / 2 = (B / 4) − 4] or by doubling the numbers of this revised version to give integral equivalence with the T-Scale. The result is a decimal formula F′double = T = (B / 2) − 4 named the TF-Scale where TF stands for Tornado Force. This harmonious 10-digit scale has all the criteria needed for world-wide practical effectiveness.     

准两年振荡对大气中微量气体分布的影响

NCAR的包含化学、辐射、动力相互作用的两维模式（SOCRATES）移植回国后进行了初步的模拟试验,用以研究某些对环境问题重要的微量气体的化学、辐射、动力传输过程。在不考虑极地平流层云和气溶胶表面非均相化学等情况下,模式积分多年,计算结果稳定,模拟的风场、温度场显示出正常的季节变化,模拟的微量气体分布与卫星实测资料对照,结果也比较一致。为了探讨热带平流层风场的准两年周期振荡（QBO）对平流层微量气体分布的影响,我们做了QBO强迫的数值试验,即在模式中加入QBO强迫,并与不考虑QBO强迫的模拟结果对比。结果表明,QBO与其相关的次级环流所引起动力输送的变化,使平流层微量气体分布发生变化。     

Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230...     

流场配置及地形对西南低涡形成的动力作用

本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用.