Identifying the Origin of Anomalous High Tropospheric Ozone in the Ozonesonde Data at Uccle by Comparison with Nearby De Bilt

Abstract

The ozonesonde stations at Uccle (Belgium) and De Bilt (Netherlands), separated by only 175?km, offer a unique opportunity to test the influence of different ozonesonde types and different correction strategies, as well as to detect the presence of inhomogeneities in the ozonesonde time series resulting from changes in sounding equipment (solution, radiosonde, ozonesonde, interface, sounding software, etc.). In particular, we highlight a 2.5 year period (beginning of 2007 to mid-2009) of anomalous high tropospheric ozone values measured by ozonesondes at Uccle and compare these with the observations from De Bilt. Because the ozone deviations are only observed in the free troposphere where ozone concentrations are relatively low, and not in the boundary layer or the stratosphere, this issue is directly related to the sensitivity of ozonesondes. Therefore, the effect of every instrumental change, even though small, during this 2.5 year anomalous period is analyzed considering a change in the radiosounding equipment, different ozonesonde batches, operational differences at the stations, differences on ascent and descent during the anomalous period; an environmental cause is also examined. Unfortunately, one single, specific cause for the observed high tropospheric ozone values at Uccle could not be identified. There are two explanations consistent with the observations and not ruled out by the analysis here: 1) the majority of the ozonesondes used at Uccle between March 2007 and August 2009 needed longer conditioning of their sensors and, therefore, behaved more accurately at low ozone concentrations during their descent or when used a second time, and 2) an environmental origin arising from a local difference in the air mass between Uccle and De Bilt and between the ascent and descent.     

拉萨地区1998年夏季臭氧总量及垂直廓线的观测研究

该文根据1998年6~10月上旬在拉萨地区进行的臭氧总量及臭氧垂直廓线的观测结果, 并结合同期同纬度其他两个臭氧站数据资料, 证实了以拉萨地区为代表的青藏高原在夏季存在“臭氧低谷”的现象.分析表明, 地基和卫星观测的臭氧总量有一定误差. Umkehr观测反演结果表明夏季拉萨地区平流层臭氧分布和同纬度其他地区相比略有不同; 在对流层, 探空资料显示了该地区对流层臭氧有低值分布的特征.     

高性能计算系统性能评测方法及其应用

为满足国家级气象数值模式业务系统对高性能计算资源不断增长的需求,提供规模更大、性能更优的高性能计算支撑平台,在高性能计算系统引进工作中开展了基于气象数值模式应用的高性能计算系统性能评测技术研究。该文将行业标准与实际业务应用相结合,设计了高性能计算系统性能评测方案,建立了中国气象局气象行业高性能计算系统性能评测模型。共选取10个测试程序,分别对单节点性能、网络性能和加速比等8个指标进行了测试和量化评分,并对主要测试结果中具有代表性的气象要素场进行了物理意义合理性检查。评测结果表明:评测方案设计合理,评测模型研究取得较好效果,保障了高性能计算系统引进工作顺利完成。     

Toward an improved global network for determination of tropospheric ozone climatology and trends

An examination of typical tropospheric ozone variability on daily, monthly, annual and interannual timescales and instrumental precision indicates that the current ozonesonde network is insufficient to detect a trend in tropospheric ozone of 1% per year at the 2 level even at stations with records a decade in length. From a trend prediction analysis we conclude that in order to detect a 1% per year trend in a decade or less it will be necessary to decrease the time between observations from its present value of 3–7 days to 1 day or less. The spatial distribution of the current ozonesonde stations is also inadequate for determining the global climatology of ozone. We present a quantitative theory taking into account photochemistry, surface deposition, and wind climatology to define the effectively sampled region for an observing station which, used in conjunction with the instrumental precision and the above prediction analysis, forms the basis for defining a suitable global network for determining regional and global ozone climatology and trends. At least a doubling of the present number of stations is necessary, and the oceans, most of Asia, Africa, and South America are areas where more stations are most needed. Differential absorption lidar ozone instruments have the potential for far more frequent measurements of ozone vertical profiles and hence potentially more accurate climatology and trend determinations than feasible with ozonesondes but may produce a (fair weather) biased data set above the cloud base. A strategy for cloudy regions in which either each station utilizes both lidars and sondes or each station is in fact a doublet comprised of a near-sea-level lidar and a proximal-mountain-top lidar could serve to minimize this bias.     

Observational study of surface ozone at an urban site in East China

In this study, we present the observational data of near surface ozone and some meteorological parameters during 2004, at an urban site (36°42′ N, 117°08′ E, 34.5 m a.s.l.) of Jinan, China. Hourly ozone concentrations exceeding the standard value of China, 100 ppbv, were observed for 65 h (in 23 days) from April to October, and values exceeding US NAAQS (National Ambient Air Quality Standard) for 1 h ozone, 120 ppbv, were observed for 15 h (in 7 days) from late May to early July. Ozone formation presented the phenomenon of “weekend effect”, especially in summer. Monthly variation of ozone coincided with temperature except for July and August. The low ozone levels in July and August may be due to the short sunshine duration and much rainfall during this period. Among these meteorological parameters, daily averaged ozone shows a significant correlation with temperature (r = 0.66) in the year and with relative humidity (r = − 0.75) in summer. Throughout the year, high ozone concentrations were mainly associated with the wind from 180 to 247.5°, while high ozone concentration seemed to have no obvious correlation with a given wind direction in summer. An anomalous nocturnal high ozone episode during 23–25 May 2004 was investigated. Growth fractions of ozone during the nighttime episode were 62.2% and 71.1% for 23 and 24 May, respectively. Synoptic analysis shows that favorable synoptic condition had presumably elevated the background ozone level in this region. Backward trajectory analysis shows that the increase of ozone concentration and the relatively constant high ozone concentrations during the night of May 23 might originate from the transport of ozone rich air mass above boundary layer. Transport of ozone from Yangtze Delta and East Central China might be a significant process for the high ozone level during night May 24 at Jinan.     

四川部分台站迁移新旧站址观测资料对比评估

利用四川近年台站迁移新旧站址对比观测资料,采用统计检验方法,对新旧站址观测资料进行对比评估.结果表明：迁站后观测环境得到改善,热岛效应影响减小,气温降低,相对湿度和风速升高.迁站对气温极值的影响大于平均值,对降水、相对湿度和风向的影响较大,新旧站址的风向一致性较差.由于旧站址遭受破坏的程度,周边障碍物的存在形式、所处方位、距离、下垫面状态及迁移距离、高差等的不同,造成对气象要素的影响程度会不同,从而造成迁站对各站及各要素影响的差异.     

新型探测资料在滇西北高原一次暴雨过程监测中的应用

应用新型探测资料对2012年9月1日至3日在云南大理发生的暴雨天气过程进行了分析,结果表明:微波辐射计在降水时段的云底高度保持在1km以下,液态水含量越大降水强度越强,温度出现较大的波动,相对湿度高层小值区与较强降水有很好的对应关系;降水时段风廓线雷达的探测高度增高,水平风从地面到高空顺时针旋转(暖平流),垂直风速小于-4m/s,信噪比值大于40dB,信噪比强度与降水强度有正相关关系,分析结果有利于对暴雨天气展开更详尽的监测研究。     

1993年春季南极中山站上空大气臭氧的观测分析

利用球载电化学O3探空仪于1993年南半球春季在南极中山站测量了O3和温度垂直廓线，三次观测到O3 柱总量＜ 220 Du的低值，O3浓度减少从9月开始，9月中旬～10月中旬达到最大。典型O3垂直廓线表明，O3量损失最大区域在高度13～23 km之间，此高度与PSCs和火山气溶胶的存在高度有很好的对应关系。本文给出观测结果及初步分析。     

局地强对流天气分析中非常规探测资料应用

应用多种非常规观测资料对2006年6月27日夜间北京地区一次局地强对流天气过程进行了分析。结果表明：直接造成此次暴雨过程的天气系统是两个局地生成的中尺度对流云团,地面中尺度辐合线是降水主要触发机制之一,城市热岛效应为强对流天气的发生提供了有利的热力条件。微波辐射计观测量对降水的发生具有较好的指示意义,液态水含量的急剧增（减）过程,预示着降水即将出现（消亡）。风廓线雷达的连续观测能够部分揭示影响系统的细节特征,从风场配置上可以看到中低层的风切变以及降水前低层的暖平流和小尺度低涡环流,这种系统结构和配置对降水的形成和维持有着重要的意义。     

The Effect of Three Different Absorption Cross-Sections and their Temperature Dependence on Total Ozone Measured by a Mid-Latitude Brewer Spectrophotometer

Abstract

The influence of variations in atmospheric temperature and ozone profiles on the total ozone column (TOC) derived from a Brewer MKII spectrophotometer operating in Thessaloniki, Greece, is investigated using three different sets of ozone absorption cross-sections. The standard Brewer total ozone retrieval algorithm uses the Bass and Paur (1985) cross-sections without accounting for the temperature dependence of the ozone cross-sections which produces a seasonally dependent bias in the measured TOC. The magnitude of this temperature effect depends on the altitude where the bulk of the ozone absorption occurs. Radiosonde measurements for the period 2000 to 2010 combined with climatological ozone profiles were used to calculate the effective temperature of ozone absorption and investigate its effect on the retrieved ozone column. Three different ozone absorption cross-section spectra convolved with the instrument's slit function were used: those of Bass and Paur (hereafter BP), currently used in the standard Brewer retrieval algorithm; those of Brion, Daumont, and Malicet (Malicet et al., 1985; hereafter BDM); and the recently published set by Serdyuchenko et al. (2013 hereafter S13). The temperature dependence of the differential ozone absorption coefficient ranges between 0.09 and 0.13% per degree Celsius for BP, between ?0.11 and ?0.06% per degree Celsius for BDM, and between 0.018 to 0.022% per degree Celsius for S13, resulting in a seasonal bias in the derived TOC of up to 2%, 1.8%, and 0.4%, respectively. The temperature sensitivity of the differential ozone absorption coefficient for the Brewer spectrophotometer at Thessaloniki for the BP and BDM cross-sections is found to be within the range reported for other Brewer instruments in earlier studies, whereas the seasonal bias in TOC is minimized when using the new S13 cross-sections because of their small temperature dependence.     

多尺度空气质量模式系统及其验证 II.东亚地区对流层臭氧及其前体物模拟

利用一个多尺度空气质量模式系统对东亚地区2001年春季对流层臭氧及其前体物的输送与演变过程进行了模拟。为了检验模式系统模拟臭氧演变过程的能力,将模拟的臭氧浓度及其与之紧密相关的化学物种浓度,如OH自由基、HO2自由基、一氧化氮、二氧化氮、一氧化碳、乙烷和乙烯,与TRACE-P期间两架飞机在西北太平洋上空获取的大量观测资料进行了比较。比较结果表明,模拟值的平均值与相应的观测值具有相当好的一致性,且绝大多数模拟值在相应观测值的2倍范围之内;模拟的化学物种浓度的时空分布与观测结果基本相符;模式系统对于非甲烷烃中不同化学物种的输送与转化过程的处理是基本合理的,反映了光化学生成和平流层输送等过程对对流层臭氧浓度分布的影响。     

臭氧探空仪电化学反应池检测设备研制与应用

臭氧探空仪作为获取地面至上平流层区域内大气臭氧垂直结构的有效手段之一,施放之前需要进行地基检测,评估其探测性能,保证其施放之后可以获取高质量观测数据。首次介绍了国内自主研制的测试臭氧探空仪电化学反应池探测性能的地基检测系统,系统包括检测仪、数据采集模块和处理软件,主要用于检测电化学反应池的背景电流和响应时间两个指标参数。检测仪可以控制输出测试电化学反应池所需的具有不同臭氧含量的空气,测试结果通过数据采集模块传送至计算机,处理软件实现数据自动存储和处理,并提取出响应时间和背景电流。应用结果表明,该套系统检测精度高,性能稳定,可用于未来国内臭氧探空业务化的地基检测工作。     

CCSM4.0的长期积分试验及其对东亚和中国气候模拟的评估

本文利用通用气候系统模式CCSM4.0的低分辨率 (T31, 约3.75° × 3.75°) 版本进行了700年的长期积分试验, 将中国地表气温、降水及东亚海平面气压、500 hPa和100 hPa位势高度、850 hPa风场的最后100年模拟结果与观测和再分析资料进行了定性比较, 并对前三个要素的不同统计量值进行了定量计算, 系统评估了CCSM4.0对东亚及我国气候的模拟能力。结果表明, 模式能够合理模拟各变量的基本分布形态, 但幅度与观测有所差别, 其中地表气温的模拟效果最好, 降水的相对最差。具体而言, 地表气温空间分布型与观测一致, 但全年青藏高原地表气温模拟值偏高, 位于塔里木盆地的暖中心未能模拟出来; 降水空间分布型模拟较差, 除冬季不明显之外, 我国中南部全年都存在一个虚假降水中心, 并在夏季达到最强; 冬季东亚地区海陆热力对比大于观测, 夏季海平面气压场整体模拟效果不如冬季; 模式对冬、夏季500 hPa东亚大槽和西北太平洋副热带高压的主要特征刻画较好, 但模拟结果整体比观测偏强; 夏季100 hPa南亚高压强度与观测接近, 但高压范围及中心位置存在偏差; 850 hPa东亚冬季风和夏季风环流模拟较好, 但冬季西北气流偏强, 夏季索马里越赤道气流偏弱、我国东部西南气流偏强。总的来说, CCSM4.0对东亚和我国大尺度气候特征具备合理的模拟能力, 尽管在定量上还存在着不足。     

北京地区太阳紫外辐射的观测与分析研究

利用北京地区太阳辐射和其它常规气象观测资料，得到了到达地面的太阳紫外辐射的计算公式，并将计算值与观测值进行了比较，两者吻合得比较好。最后给出了北京地区地面太阳紫外总辐射的变化趋势，计算结果表明，地面太阳紫外总辐射对大气浑浊度的变化比对大气臭氧总量的变化敏感得多。     

GIS 在上海蔬菜生产资源评价与合理布局中的应用

运用地理信息系统（GIS）软件ARC/INFO,针对上海郊区各乡镇气候、土壤、区位、技术、承灾能力、水污染等方面进行综合评价,得到上海蔬菜生产优势区域,可为蔬菜基地规划、菜地迁移和蔬菜生产提供有效参考。     

超燃冲压发动机性能的准二维计算方法

为了能在双模态超燃冲压发动机流道方案初步论证中提供一种较快速的发动机性能计算方法,在二维N-S方程基础上,引入一维完全燃烧计算方法,提出了预估超燃冲压发动机性能的准二维计算方法。该方法能够计入激波、边界层分离等对发动机性能的影响,可在较短时间计算出整机推力、比冲性能和沿程热力学参数。通过对自由射流发动机计算,验证了此方法。并在此基础上,初步分析了燃料喷注位置和流道构型对发动机性能的影响。      

GRAPES_Meso区域模式积云计算方案引进及预报效果检验

云量在模式中的准确模拟既是一个重点问题,也是一个难点问题。经评估发现,在GRAPES_Meso（Global/Regional Assimilation and PrEdiction System）模式中存在模拟云量偏少的问题,而ECMWF模式中的积云云量计算方案对云量模拟具有一定优势。鉴于此,本文借鉴ECMWF积云云量计算方案对GRAPES中尺度模式中的云量计算方案进行了适当改进,并通过影响试验模拟三维云量和地面温度来验证其改进效果。结果表明:较改进前,改进云量方案模拟的云量增多,单层云量更加准确,垂直方向云层结构改进效果明显;地面温度与观测值对比误差减小。综合分析模拟结果,认为改进云量计算方案在GRAPES模式中对云量和地面温度的模拟有较好的改进。     

伊犁河谷初冬降水条件下风廓线雷达评估分析

对伊犁河谷地区初冬降水条件下风廓线雷达资料评估其数据获取率并与探空资料进行对比分析,定义两者风向偏差在10°以内或风速偏差在1 m/s范围的样本为有效样本,分别用E_v和E_d表示风速有效样本比率(风速有效样本数/总样本数)和风向有效样本比率(风向有效样本数/总样本数)。结果显示:超过80%数据获取率的高度,降雨时为3000 m,降雪时达到预设2000 m;降雪时E_v和E_d均比无降水时高,且降雪量大小与风廓线的探测高度呈正相关,降雪量大小对E_d有明显影响,对E_v无明显影响;比较不同高度数据,降雪时0～3 km范围的E_v和E_d值均比无降水时高30%左右,无降水时3～5 km范围的E_d接近100%。     

北京秋季地面O3的一维模式模拟研究

用一维光化学模式,基本模拟出静稳天气条件下2001年9月9日北京几个主要大气污染物种:O3、NO、NO2、CO以及SO2的日变化特点,并解释了影响O3及NO、NO2、CO和SO2日变化的控制因子作用。初步分析认为,地面O3对非甲烷碳氢化合物(NMHC)的变化很敏感。NMHC的增加或减少,将会造成O3的明显改变。造成9月9日夜间20:00~23:00一次污染物NO、CO和SO2浓度急剧升高的原因是由于夜间大气层结稳定情况下,大气的垂直扩散减弱,污染物在底层积累造成的。由于实际大气中,影响O3生成和损耗的机制很复杂,同时大气的平流输送是影响O3及其他污染物分布的重要因素,用一维模式虽然能够揭示出影响O3变化的几个因子的作用,但要深入分析O3产生和消耗机制,还需要用三维模式。