潮州市大气污染物与气象要素的关系

利用2006年潮州市地面气象观测资料和大气污染物浓度数据,分析了潮州市污染物的时空变化特征、污染物浓度月变化与气象要素变化关系以及污染典型日的气象因素。研究发现:潮州市的主要污染物为可吸入颗粒物(PM10),PM10全年的超标率为7.5%,空气质量夏半年优于冬半年;PM10污染物浓度月变化与地面气象要素有较高的相关性;在污染物典型日中,气象要素也是主要的影响因子。     

内蒙古沙地和草地环境下近地面PM10分布特征及其与相关气象要素的关系

利用内蒙古锡林浩特和朱日和2005年的PM10质量浓度（MPM）和相关气象要素资料,分析了沙地和草地环境下MPM的分布特征,发现MPM受沙尘天气的影响较大,非沙尘日MPM在不同下垫面条件下差别不大。进一步分析发现,气象要素对MPM有较大的影响,在选取相关气象要素参量的基础上,将各参量相乘建立了气象影响指数IPM,表示气象条件对MPM的综合作用,经检验发现锡林浩特和朱日和IPM值与MPM日均值的相关系数都大于0.70,高于MPM与其他单气象要素,月均值的线性相关性更显著。对同一气候带不同下垫面条件下不同季节IPM值与MPM的对比分析发现,气象条件对近地面MPM的影响比下垫面条件更显著。     

福州市污染物浓度时空分布及影响因子分析

利用2001年8月1日至2002年7月31日的气象资料和逐时污染物浓度数据，分析福州市污染物的时空分布特征，气象条件和非气象条件对污染物浓度的影响。结果表明：福州市的空气质量较好，夏半年空气质量优于冬半年。各污染物的日变化有明显的变化规律。污染物的浓度变化与空气污染气象条件的优劣密切相关，各气象要素对大气污染物有一定的制约关系，但并非简单的线性关系。人类活动对污染物浓度的变化影响较大。     

北京地区气溶胶PM2.5粒子浓度的相关因子及其估算模型

文中运用统计分析和气象统计预报的方法 ,使用北京白石桥小区的污染物观测资料和同期北京地区的气象观测资料 ,对影响大气污染的气象因子进行了综合分析 ,并分别建立了气溶胶PM 2 .5粒子浓度与气体污染物、气象要素场的两类统计相关拟合模型。发现气溶胶PM2 .5粒子浓度与气体污染物浓度存在不同程度的相关性 ,且与气象条件亦存在显著的相关关系 ,此类时空变化及其量化估算模型具有一定实际应用价值。通过确定气象要素场和气溶胶浓度的关系可进一步研究不同地区的污染物输送和污染源扩散影响的问题。     

大气环境影响评价中加权法选取典型气象日

为在计算大气环境影响评价中选取典型气象日,根据典型日的定义,利用2005年西安基准气候站气象观测资料和西安市环境监测站SO2、NO2和PM10日平均污染物质量浓度资料,分析西安市大气污染特征与气象条件的关系,按照不同气象要素确定权值选取典型气象日,对比西安市典型日天气现象与环境空气质量。加权法确定筛选的西安市典型气象日一般都出现在冬季,其风速、湿度都较小,计算得到的混合层高度也较小,基本符合污染严重的条件。结果表明大气环境影响评价中用加权法筛选典型日提高了计算精度,更真实地反映该地区的实际气象条件对大气污染物分布浓度的影响情况,基本上是可行的,能够为大气环境评价预测日平均质量浓度提供可靠的方法。     

北京高速公路大气能见度与气象条件的相关分析

从能见度与气象要素的日变化、逐月变化、季节变化特征以及不同等级能见度与对应气象要素平均值的依赖关系等不同角度,统计分析了北京首都机场和八达岭高速公路大气能见度与地面气象要素的相关性,并进行了高速公路大气能见度与地面气象要素相关性普查。结果表明,北京高速公路大气能见度与相对湿度呈明显负相关,与风速和气压呈正相关,高湿和小风是出现低能见度的主要气象条件。     

日照市区PM10污染物特征及其与气象要素的关系

对2002年1月1日～2002年12月31日日照市环境监测中心提供的PM10（可吸入颗粒物）日平均浓度资料和对应时段的日照市地面气象资料做了深入的分析，揭示了污染物PM10变化特征及其随气象要素的变化规律。同时分析了主要污染物PM10与地面风速、风向间的相关关系，发现日照市大于等于3级的PM10污染日均出现在1-4月，地面风速对污染物PM10浓度有一定影响，当地面风速超过5m／s时，3级及以上污染日很少出现，当地面风速超过6．5m／s时，随着风速的提高，污染物浓度呈下降趋势。污染物浓度呈明显的季节变化，冬、春季节明显高于夏、秋季节。     

2019年冬季呼和浩特市大气污染频发的气象条件分析

利用2015—2019年呼和浩特市大气污染物质量浓度、气象要素观测及NCEP FNL 1°×1°再分析资料,分析近5 a冬季环境空气质量特征及与大气污染扩散紧密相关的气象要素和大气边界层特征,研究2019年冬季呼和浩特市大气污染频发的气象条件变化特征。结果表明:(1)呼和浩特市冬季较易出现污染天气,以PM 2.5污染为主,2019年冬季,大气污染呈现出污染物积聚难于扩散、污染长时间持续、污染天数和重污染占比均显著增高等特点。(2)2019年冬季呼和浩特市气象条件呈现出平均风速偏小、小风日数偏多、南风出现频率增多、相对湿度偏高、混合层高度偏低、通风系数较小、逆温日数较多等特征。     

多尺度气象条件对济南PM2.5污染的影响

长时间序列空气质量数据和气象数据分析济南大气污染与气象条件关系的研究相对较少。利用2010-2016年济南市环境空气质量监测数据、气象再分析和观测数据,分析了济南市PM_(2.5)污染特征、PM_(2.5)浓度与2 m温度(T)、2 m相对湿度(RH)、10 m高度U和V风速(U和V)、10 m风速(WS)、K指数(K)、A指数(A)和边界层高度(BLH)的相关性、天气类型对PM_(2.5)浓度的影响,并基于逐步回归分析方法构建统计模型,利用解释方差量化气象条件对PM_(2.5)浓度变化的影响。分析发现,济南PM_(2.5)浓度存在显著的季节变化和年际变化特征,年均PM_(2.5)浓度呈下降趋势;近地面PM_(2.5)浓度与T、RH、K和A显著正相关,与WS和BLH显著负相关,U和V与PM_(2.5)浓度相关性不显著(p0. 05);不同天气类型对应的PM_(2.5)浓度均值存在显著差异;基于回归模型分析发现气象条件可以解释10%～40%的PM_(2.5)浓度逐日变化,气象条件的影响有明显的季节变化。     

大气污染物非线性回归模型构建

本文基于重庆主城区（沙坪坝站）2014—2018年逐日同期同步观测的气象要素和环境空气质量监测数据进行分析。首先通过对不同大气污染物与各种气象要素进行相关性分析，剔除影响预报模型共性的气象因子，明确显著影响空气质量的气象要素；然后结合污染物排放、大气扩散过程和湿沉降作用机理；最后构建乘幂与线性叠加的混合模式的空气质量预报方程。结果表明：构建的非线性回归方程能较为真实地反映主要大气污染物与气象要素的相互影响关系，回归模型预报检验准确率高（预报评分达87.6）。     

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.     

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。     

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.     

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.     

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     

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.     

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...     

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.