平流层臭氧和辐射场的季节分布特征

利用美国NCAR化学气候耦合模式WACCM3对平流层温度场、风场、臭氧及辐射场进行了模拟.结果表明,在适宜飞艇长期驻留的准零风层高度20～22km(对应大气压强范围为50～30hPa,以下均采用气压值表征对应大气高度),7-8月风速小于5m·s-1的风带可长期稳定在40°N以北.臭氧空间分布显示,在30hPa气压高度处中国地区臭氧浓度出现了带状分布,30hPa高度以下低纬度地区臭氧浓度低于中纬度地区.平流层太阳加热率的时空变化表明,在平流层上层,太阳加热率可达100×10-6K·s-1,而在平流层下层,只有10×10-6K·s-1.6-8月中国区域的太阳加热率大于9月;在100～30hPa高度内,中纬度地区太阳加热率高于低纬度地区,在30hPa高度以上,低纬度地区太阳加热率高于中纬度地区;8-9月30～40hPa高度处,太阳加热率的空间变化较小.在30hPa高度上,太阳加热率在40°N昼夜变化最大;50hPa高度处,太阳加热率的昼夜变化小于30hPa高度处,而且白天太阳加热率出现极大值的纬度明显靠北.平流层低纬度地区的长波加热率小于中纬度地区.青藏高原由于地形特殊,其6-7月的臭氧浓度、太阳加热率和长波加热率均小于同纬度其他地区.      

垂直对天顶测量的紫外前向散射探测臭氧总量的可行性研究

选用SBDART模式作为大气辐射传输计算模式,通过模拟计算和结果分析探讨无云的晴天、垂直对天顶观测的紫外前向散射反演大气臭氧总量的可行性.计算表明,穿透能力与探测灵敏度之间的复杂联系使得探测波长应随着sΩ0的增大而波长变长,若用波长对探测,则波长对中较短的波长也应随着sΩ0的增大而增大.另外大气的臭氧总量越少,反演结果受下垫面反照率、气压和仪器精度的影响越大,因而反演误差越大.当强度Ii的测量精度为±1%时,下垫面反照率R和气压P0的分辨率分别达到±0.05和±50 hPa,若用单波长探测,则在大气臭氧总量Ω0和s都较小时,反演结果大于5%;若选用波长对进行探测,由于R和P0的误差对反演结果的影响降低,故精度大大提高.Ii,R和P0在上述精度下,选取适当的波长对进行探测,精度至少可达±4%,当臭氧总量高于350 DU时,可达±2%.      

基于WACCM+DART的临近空间SABER和MLS温度观测资料同化试验

基于WACCM+DART（Whole Atmosphere Community Climate Model,Data Assimilation Research Test-Bed）临近空间资料同化预报系统,以2016年2月的一次平流层爆发性增温（SSW）事件为例,开展了临近空间SABER（Sounding of the Atmosphere using Broadband Emission Radiometry）和MLS（Microwave Limb Sounder）温度观测资料集合滤波同化试验.结果表明:同化SABER和MLS温度观测资料可显著降低WACCM模式在中间层和平流层中上部（0.001～10hPa）大气温度场的预报误差,改善CR试验在SSW发生时中间层变冷现象偏强、纬向风场首次发生反转的层次偏低以及增温恢复阶段0.1～10hPa的东风层提前消退、纬向风速偏大、平流层顶位置偏高等现象.基于ERA5（The Fifth Generation of ECMWF Reanalyses）再分析资料的检验表明:同化SABER和MLS温度资料明显有利于减小北半球高纬度地区（60°-90°N）平流层中上层和下中间层（0.1～14hPa）纬向风场以及平流层和中间层中下层（0.01～100hPa）温度场的分析误差;同化低层大气观测也有利于减小0.1～14hPa纬向风场和0.01～100hPa温度场的分析误差,但是不如同化SABER和MLS温度资料对临近空间纬向风场和温度场分析误差的改善效果显著.      

基于SABER的平流层顶温度的时空特征分析

利用SABER探测器2002—2017年超过一个太阳活动周的数据,以大气垂直方向上40～60km的最大温度作为平流层顶温度（T_sp）,分析50°S—50°N T_sp的时空分布特征.结果表明:T_sp具有明显的纬度特征和季节特征,在赤道和南北半球夏季温度较高,而在南北半球冬季的40°—50°纬度附近温度有最低值.再利用EOF方法分析T_sp,发现其第一模态的解释率达91%,且时间系数与平流层顶高度相关性最大,为-0.75,与平流层顶臭氧体积混合比相关性约0.49,与日地距离相关性为0.44,与太阳活动性（太阳活动指数,太阳黑子数）的相关性约0.33.依据该相关关系,进一步分析各变量原始场,发现T_sp和平流层顶臭氧体积混合比的纬度变化近似相反;与日地距离的季节变化有明显的负相关,约-0.81,且这种相关性与日地距离有弱的正相关关系;年平均T_sp在2002—2017年的变化约为2K,与F_10.7的相关系数为0.6,在南北纬20°附近与太阳活动指数F_10.7的相关性最大,约0.74.      

子午工程首次火箭探空数据准单色惯性重力波特性分析

利用2010年6月3日子午工程首次气象火箭探测的温度和风场数据,采用矢端曲线法分别从平流层（20~50km）和对流层（0~15km）廓线提取了海南火箭发射场上空准单色惯性重力波参数.火箭探测的平流层和对流层两个准单色惯性重力波分别向上和向下逆风传播,固有周期为20.1h和22.4h,垂直波长为9.5km和4.0km,水平波长为2900km和753km,垂直群速度c_gz为0.0887m·-1和0.0298m·-1,水平群速度c_gh为12.7m·-1和3.65m·-1,λ_h/λ_z为305:1和188:1,c_gh/c_gz为143:1和122:1.      

利用WACCM-3模式对平流层动力、热力场及微量化学成分季节变化的数值模拟研究

利用美国NCAR最新的化学-气候耦合模式WACCM-3对平流层风场、温度场以及平流层臭氧等多种微量气体成分(O3, CH4, N2O, H2O, HCl, HNO3)的季节变化进行了数值模拟, 并使用ECMWF再分析资料与美国UARS卫星 搭载的HALOE, MLS, CLAES等探测器的观测资料, 对模式输出的动力、热力及化学成分浓度的气候平均值进行了验证. 结果表明, 在气候平均海表温度值驱动下, WACCM-3模式能够很好地再现ECMWF资料中平流层纬向平均风场与温度场的季节变化. 模拟结果中平流层化学成分的经向-垂直分布及其季节变化与卫星观测结果基本一致. 模式的动力、热力场在极地平流层以及热带对流层顶等区域存在一定的偏差. 这些偏差对于微量气体成分分布 的模拟具有一定影响, 特别是南半球冬(7月)、春(10月)季节南极平流层低层极夜 急流偏强, 造成极地地区附近的输送障碍增强, 从而导致CH4, N2O, H2O浓度比观测偏低. 此外, WACCM-3缺少热带平流层风场的准两年振荡(QBO) 机制, 这对于热带平流层东风急流以及低纬度平流层O3, CH4, N2O, H2O等成分经向输送的模拟结果也有一定影响.      

风云三号C星GNOS北斗掩星电离层探测初步结果

利用风云三号卫星C星GNOS掩星探测仪电离层数据,分析了2013年10月FY-3C GNOS探测的北斗掩星电离层廓线分布,将2013年10月1日至2015年10月10日期间FY-3C GNOS观测的F₂层峰值电子密度（N_mF₂）与地面电离层测高仪观测结果进行对比,验证了FY-3C GNOS北斗电离层掩星的探测精度.结果表明,FY3-C GNOS北斗电离层掩星与电离层测高仪探测的N_mF₂数据相关系数为0.96,平均偏差为10.21%,标准差为19.61%.在不同情况下其数据精度有如下特征:白天精度高于夜晚;夏季精度高于分季,分季精度高于冬季;中纬地区精度高于低纬地区,低纬地区精度高于高纬地区; BDS倾斜同步轨道（IGSO）卫星精度高于同步轨道（GEO）卫星和中轨道（MEO）卫星.FY-3C GNOS北斗电离层掩星与国际上其他掩星电离层数据精度的一致性对GNSS掩星探测资料的综合利用具有重大意义.      

太阳光谱辐射强度变化对地球能量平衡的影响分析

目前太阳对地球能量平衡影响的研究大都是以太阳总辐射通量密度作为输入参数的. 本文以美国航空航天局（National Aeronautics and Space Administration,NASA）太阳辐射与气候实验项目的卫星实测数据为基础,对太阳上升相（2010年上半年）和下降相（2007年12月）期间太阳光谱变化对地球能量平衡的影响进行了研究. 结果表明,2010年上半年较强的太阳总辐射通量密度主要是由紫外及红外波段的能量增强引起的,其在200～400nm 和760～4000nm波段内的平均能量分别增加了0.11%和0.05%,而在 400～760nm可见光区的能量却呈减小趋势,平均减小量为0.05%. 通过对MLS2.2全球臭氧日数据进行再分析后发现,相对于2007年12月,2010年上半年平流层臭氧浓度也有所增加,其中在太阳紫外辐射呈现较大增强的2月和3月,其臭氧增量也相对较大,最大值分别出现在33km和40km处,值为0.6mL·m-3和0.62mL·m-3. 因此,可见光区能量减弱与平流层臭氧浓度增加的双重削弱作用致使虽然2010年上半年的太阳总辐射通量密度较大,但是到达对流层顶的太阳辐射却有所减小,最大减小量出现在3月,值为0.15W·m-2. 这一结果说明,太阳活动或总辐射通量密度的增强也有可能对地球对流层系统起到冷却作用.      

北斗系统UERE及定位精度评估

用户测距误差（URE）与用户设备误差（UEE）是影响定位精度的主要因素.民航是北斗系统的高端用户,监测其对民航机场的覆盖性和服务性能十分必要.本文根据华东、华南、华北、西北地区4个民航机场观测站的北斗实测数据,分析了各机场卫星的可见性.根据URE的解算方法、电离层修正模型、对流层修正模型以及定位精度的评估方法,给出了对应的性能评估结果.研究发现:可见星数均在6～14颗,满足定位要求; 95%置信度下,电离层延迟优于7.50m,对流层延迟优于13.28m,地球静止轨道卫星（GEO）、倾斜地球同步轨道卫星（IGSO）、中圆轨道卫星（MEO）卫星的URE值分别优于2.36m,1.72m,2.59m,满足北斗规范的要求;95%置信度下,定位精度水平方向优于3.63m,垂直方向优于6.98m.结果表明北斗系统在民航机场监测站的覆盖性及服务性能良好.      

1MΩ～100GΩ高值电阻器高精度的校准方法CSCD

高阻计、数字源表等仪器在半导体行业有着广泛的应用. 但目前市场上1MΩ-100GΩ高值电阻器准确度（±1. 0x10-3 -±1. 0x10-2）无法满足高阻计、数字源表等仪器电阻参数的溯源需求. 本文提出了一种高精度的高值电阻器的校准方法,该方法由两个多功能校准源和指零仪组成的比较电桥实现. 根据校准方法组建了1MΩ-100GΩ测量系统,测量结果的不确定度为3. 0x10-5 -8. 0x10-4,可满足市场上绝大部分高阻测量仪器的校准需求.     

Ozone variations observed during the International Ozone Rocket Sonde Intercomparison

The International Ozone Rocket Sonde Intercomparison (IORI) conducted at Wallops Island during October 1979 provided a unique opportunity to observe ozone variations in great detail from several observing systems. The measurement period lasted 15 days during which time ozone observations were taken by ground-based, balloon, rocket, and satellite instruments. These data provided a unique opportunity for diagnosing regional stratospheric variability over a 2 week period. Examination of NMC analyses indicated that during this period the stratospheric polar vortex moved southeastward bringing air from high latitudes to Wallops Island above 10 mb. A concurrent change was observed in the upper stratosphere ozone fields observed by Nimbus-7 SBUV and in the ozone vertical distribution measured by the rocket soundings. In this study the satellite and rocket measurements are compared. The agreement is good, certainly within the errors of the measurements.     

Ozone reference models for CIRA

The ozone reference model which is to be incorporated in the COSPAR International Reference Atmosphere (CIRA) is described and compared with other measurements of the Earth's ozone distribution. Ozone vertical structure models from approximately 25 to 90 km are provided combining data from five recent satellite experiments (Nimbus-7 LIMS, Nimbus-7 SBUV, AE-2 SAGE, Solar Mesosphere Explorer (SME) UVS, and SME IR). The results include the latest improvements in the SBUV algorithms using the most recent estimates of ozone cross sections. Also, the latest refinements in SME algorithms are incorporated. These algorithm improvements have improved agreement between the satellite data sets. Standard deviations are provided of monthly zonal means, and an estimate of the interannual variability is given. The models based on satallite data compare well with the Krueger and Minzner mid-latitude model incorporated into the U. S. Standard Atmosphere which is based on rocket and balloon measurements. Other comparisons are shown with Umkehr and more recent balloon data. Models are also provided of total columnar ozone reflecting recent improved estimates of ozone cross section. Information is provided on semiannual and annual variations. Other systematic variations including estimates of diurnal variations in the mesosphere will be included in the CIRA document.     

Comparison of ozone data derived from SBUV and SAGE with emphasis on longitudinal variations

Stratospheric ozone observations by the SAGE and SBUV satellite instruments in March and April, 1979 have been analyzed. All SAGE profiles have been smoothed vertically over 8 km to provide some compatibility with the SBUV vertical resolution. Comparing the zonal mean ozone mixing ratios against smoothed LIMS profiles, it is inferred that SAGE is systematically overestimating ozone by approximately 20% at tropical latitudes at pressures lower than 5 mb and that SBUV is underestimating ozone by approximately 15% at 50–70° latitude at 10 mb. A comparison of the longitudinal variations of ozone by SBUV and SAGE is made and the detectability of planetary waves in ozone is emphasized. The uncorrelated portion of the SAGE variances are found to be approximately consistent with the SAGE noise model. Based on the correlated variances, the amplitudes of the smoothed SAGE planetary waves in ozone are found to be the same, on average, as in the SBUV experiment at mid-latitudes between 1 and 10 mb. Planetary wave detectability is illustrated during two several day periods at mid-latitudes and a persistent and theoretically-consistent relationship between ozone and temperature is noted. These examples, however, indicate that differences between ozone planetary wave amplitudes derived from the two sensors may occur when there is a strong vertical gradient in wave amplitude.     

Measurement of middle atmospheric ozone density profile by rocket-borne radiometer onboard KSR-II

KSR-II, a two-stage sounding rocket of KARI was launched successfully at the Korean Peninsula on June 11, 1998. The apogee of the rocket was 137 km. For the ozone measurement, 8-channel UV and visible radiometers were onboard the rocket. The rocket measured an in situ stratospheric and mesospheric ozone density profile over Korea during its ascending phase using the radiometer and transmitted the data to ground station in real time. The maximum ozone density occurs near 25 km. Retrieved profile has a random error (1σ) of approximately 15% for altitude below 20km, 7% between 20-50 km and 10% greater than 50 km. The retrieved data were compared with Dobson spectrophotometer, ozonesonde, and HALOE onboard the UARS. Our results are in reasonable agreements with others.     

Proposed reference models for ozone

Ozone reference models are proposed here similar to the Keating and Young 1985 models which were prepared for the new COSPAR International Reference Atmosphere. This paper updates tables provided in the Keating and Young ozone model, giving improved monthly zonal mean total column ozone in 10° latitude increments, improved monthly zonal mean ozone volume mixing ratios (ppmv) from 20 to 0.003 mb in 10° latitude increments, and conversion tables providing ozone vertical structure in other units. Also, a new table is provided giving ozone vertical structure as a function of altitude (from 25 to 80 km), latitude, and month. The models are based on measurements from six contemporary satellite instruments.     

Proposed ozone reference models for the middle atmosphere

Since the publication of the last COSPAR International Reference Atmosphere (CIRA 72), large amounts of ozone data acquired from satellites have become available in addition to increasing quantities of rocketsonde, balloonsonde, Dobson, M83, and Umkehr measurements. From the available archived satellite data, models are developed for the new CIRA using 5 satellite experiments (Nimbus 7 SBUV and LIMS, AEM-2 SAGE, and SME IR and UVS) of the monthly latitudinal and altitudinal variations in the ozone mixing ratio in the middle atmosphere. Standard deviations and interannual variations are also quantified. The satellite models are shown to agree well with a previous reference model based on rocket and balloon measurements.     

Verification of satellite observations of stratospheric minor constituents

The TIROS-N operational meteorological satellite observing system will have the capability of determining global ozone amounts from two instruments by 1985. The TIROS Operational Vertical Sounder (TOVS) yields total ozone amounts through measurements of atmospheric infrared radiances. The Solar Backscatter Ultraviolet (SBUV/2) spectrometer yields total ozone amounts and vertical ozone profiles through measurements of the solar ultraviolet radiation backscattered by the atmosphere. The current operations plan calls for single satellites containing both instruments system with local afternoon equator crossing times. They will be launched at approximately 18 month intervals.The satellite ozone products will require verification using commonly accepted references. For total ozone, Dobson spectrophotometer determinations are to be used. For vertical profiles, no clear choice now exists among balloon-launched chemical sondes, rocket-launched optical sondes or Dobson Umkehr measurements. The applicability and use of these measurement systems are discussed with emphasis on the need for the verification data consistent with the operational satellite lifetimes.Another major source of data for verification is other satellite systems. Comparisons of vertical ozone profiles from several concurrent satellites is discussed. This includes results from SAGE, LIMS and SBUV.     

Long term solar induced variations in total ozone, stratospheric temperatures and the tropopause

The variations of total ozone, stratospheric temperature and tropopause temperature are presented for the past 3 solar cycles for the summer months of the northern hemisphere. Ground-based, 30-year total column ozone series, filtered from its seasonal, QBO, El Nino/Southern Oscillation (ENSO) and trend components are found to be correlated to the 11-year solar cycle. Model calculations with a 2D chemical transport model are consistent with the observations. Mean stratospheric temperature variations, between levels 100 and 10 hPa, show also the same variation, correlated with the observed 11-year solar cycle, and the tropopause temperature increases in the same manner, in response to a warmer stratosphere during solar maxima.     

An analysis of preliminary SAGE II data on ozone and NO2

Zonal mean mixing ratios of ozone and NO₂ measured by SAGE II on several days in March and April, 1985 are compared against zonal means for this time of year previously measured by SAGE I, SBUV, and LIMS. After allowing for calculated diurnal variations of these gases, agreement within 15% is found for ozone and 20% for NO₂. It is noted that the profile error bars given on the SAGE II data tapes need to be carefully interpreted and that the measured tropical variances suggest that these error bars are being somewhat overestimated. Planetary waves in both ozone and NO₂ in the middle stratosphere should be derivable from the SAGE II measurements.