北京地区对流层顶变化及其对上对流层/下平流层区域臭氧变化的影响

根据2001～2003年期间获得的大气臭氧探空资料,揭示了北京地区上空对流层顶高度的某些变化特征及其对上对流层(UT)和下平流层(LS)区域内大气臭氧含量变化的影响.结果显示:北京地区上空对流层顶高度的平均值约11.1 km,其变化范围为7.7～14.4 km,臭氧层顶始终处在对流层顶下方约0.9 km高度处.对流层顶高度变化与臭氧总量变化之间的关系相对较弱.通常情况下,LS中的臭氧积分量明显高于UT中的相应值,并且二者呈相反的季节变化特征.北京地区上空仲夏和初秋季节第一对流层顶出现的频数明显减少,在第一对流层顶消失的情况下,LS中的臭氧积分量明显减少,而UT中的臭氧积分量明显增加,臭氧量减少最多发生在200～100 hPa层次中,而臭氧量增幅最大的层次是400～250 hPa.     

The Role of Ozone Depletion in the Lack of Cooling in the Antarctic Upper Stratosphere during Austral Winter

Temperature trends in the upper stratosphere are investigated using satellite measurements from Stratospheric Sounding Unit(SSU) outputs and simulations from chemistry–climate models(CCMs) and the Coupled Model Intercomparison Project Phase 6(CMIP6). Observational evidence shows a lack of cooling in the Antarctic, in contrast to strong cooling at other latitudes, during austral winter over 1979–97. Analysis of CCM simulations for a longer period of1961–97 also shows a significant contrast in the...     

Observations of Dynamic Turbulence in the Lower Stratosphere over Inner Mongolia Using a High-resolution Balloon Sensor Constant Temperature Anemometer

We present characterizations of the dynamic turbulence in the lower stratosphere measured by a new balloon-based system designed for detecting finer scale dynamic turbulence. The balloon-based system included a constant temperature anemometer(CTA) operating at a sampling rate of 2 k Hz at an ascent speed of 5 m s^-1(corresponding to a vertical resolution of 2.5 mm), an industrial personal computer, batteries, sensors for ambient temperature and humidity, an A/D converter, and others. The system was successfully launched to 24 km altitude over Bayannur City, Inner Mongolia Province. Results show the spatial intermittence of the turbulence layers, with clear boundaries between turbulent and nonturbulent regions. This is the first time that the dynamic turbulence spectrum down to the viscous sub-range has been obtained throughout the lower stratosphere over China. With that, the energy dissipation rates of dynamic turbulence could be calculated with high precision. The profile of the dissipation rates varied from 7.37 × 10^-7 to 4.23 W kg^-1 and increased with altitude in the stratosphere.     

北半球平流层低层大气季节内振荡特征

利用奇异谱分析方法（SSA）分析了1975年1月1日至12月31日北半球30hPa高度场变化特征，结果发现:平流层低层大气除了年变化及季节变化趋势外，还存在明显的季节内振荡，最显著的周期为20～60天；在持续性异常多发地区，30hPa高度场变化中20～40天周期振荡占优势，而在其它一些地区则盛行40～60天周期振荡；对流层持续性异常主要同对流层高度场的20～40天振荡有关，并可能通过这种周期振荡同平流层低层相同周期的振荡的相互作用影响平流层低层大气季节内变化。     

Distribution and Variation of Carbon Monoxide in the Tropical Troposphere and Lower Stratosphere

The authors examine the distribution and varia- tion of carbon monoxide （CO） in the tropics from the sur- face to the lower stratosphere. By analyzing space-borne microwave limb sounder （MLS） measurements, measure- ments of pollution in the troposphere （MOPITT） and mod- em-era retrospective analysis for research and applications （MERRA） meteorological products, and atmospheric chemistry and climate model intercomparison project （ACCMIP） surface emission inventories, the influences of atmospheric dynamics and surface emissions are investi- gated. The results show that there are four centers of highly concentrated CO mixing ratio over tropical areas in differ- ent seasons： two in the Northern Hemisphere and another two in the Southern Hemisphere. All of these centers cor- respond to local deep convective systems and mon- soons/anticyclones. The authors suggest that both deep convections and anticyclones affect CO in the tropical tro- posphere and lower stratosphere--the former helping to transport CO from the lower to the middle troposphere （or even higher）, and the dynamical uplift and isolation effects of the latter helping to build up highly concentrated CO in the upper troposphere and lower stratosphere （UTLS）. Similarly, there are two annual surface emission peaks in- duced by biomass burning emissions： one from the North- ern Hemisphere and the other from the Southern Hemi- sphere. Both contribute to the highly concentrated CO mixing ratio and control the seasonal variabilities of CO in the UTLS, combining the effects of deep convections and monsoons. Results also show a relatively steady emission rate from anthropogenic sources, with a small increase mainly coming from Southeast Asia and lndia. These emis- sions can be transported to the UTLS over Tibet by the joint effort of surface horizontal winds, deep convections, and the Asian summer monsoon system.     

全球平流层下部降温及其对纬向风的影响

利用NCEP/NCAR再分析资料,结合HALOE的臭氧和甲烷卫星观测资料,分析100~50 hPa的平流层下部温度变率及其与微量气体和平均纬向风的关系。结果表明,全球平流层下部大气温度自1948年至今总体呈下降趋势,而近十几年,全球平流层下部温度下降更加显著。热带和低纬甲烷的增长可能是其降温的一个重要原因。此外,由于平流层下部温度变率的经向不均匀性,同时还会引起该地区平均纬向风的变化。     

瑞利散射激光雷达探测平流层和中间层低层大气温度

介绍了一台瑞利散射激光雷达,它能够探测22～60 km范围内大气温度的垂直分布;比较了两种反演温度的数据处理方法.该激光雷达分别与UARS/HALOE卫星和无线电探空仪观测结果进行了对比,均表现了较好的一致性.同时还模拟分析了平流层低层气溶胶对计算温度的影响.     

A 7-Year Lidar Temperature Climatology of the Mid-Latitude Upper Troposphere and Stratosphere

Abstract

The Purple Crow Lidar (PCL) is a large power-aperture product monostatic laser radar which until 2010 was located at the Delaware Observatory (42°52′N, 81°23′W, 225 m elevation above sea level) near the campus of the University of Western Ontario. It is capable of measuring temperature from 10 to 110 km altitude, as well as water vapour in the troposphere and stratosphere. We use upper tropospheric and stratospheric vibrational Raman N₂ backscatter-derived temperatures to form a climatology for the years 1999 to 2007 from 10 to 40 km attitude. The lidar temperatures are validated using nearby radiosonde measurements from Detroit and Buffalo. The measured temperatures show good agreement with the radiosonde soundings. An agreement of ±1 K is found during the summer months and ±2.5 K during the winter months, validating the calibration of the lidar to within the geophysical variability of the measurements. Comparison between the PCL measurements and the Committee on Space Research International Reference Atmosphere, 1986 (CIRA-86) and the Mass Spectrometer Incoherent Scatter-90 (MSIS-90) models show the models are as much as 5 K warmer below 25 km and 2 to 4 K colder above 25 km during the summer months, in large part because the measured tropopause height is consistently lower than in the models.     

北半球平流层中低层纬向风季节转换及转换层特征的分析研究

使用1979～2005年NCEP/NCAR 再分析数据,分析了北半球平流层中低层（300 hPa至10 hPa）纬向风的季节转换规律,并采用二维空间场相似性方法确定了平流层的季节过渡日期。分析表明,平流层大气环流基本为冬夏二元状态,冬夏转换具有突变性;其季节过渡在纬向是接近同步进行的,而在经向则有时间差异,无论是冬夏转换还是夏冬转换高纬都要早于低纬。在平流层中部（10～70 hPa）季节过渡是自上而向下进行的;而在平流层下部（100～200 hPa）季节过渡的上下传递关系则比较复杂,在不同的纬度带有不同的表现。在北半球热带外地区,平流层中部东风期的起止日期与相似性方法计算得到的平流层季节过渡日期之间具有较好的对应关系,在东风期之前和之后往往各存在持续10天左右的零风—弱风期。     

In situ Measurement of H2O and CH4 with Telecommunication Laser Diodes in the Lower Stratosphere: Dehydration and Indication of a Tropical Air Intrusion at Mid-Latitudes

Telecommunication laser diodes emitting near 1.39 m and 1.65 m in combination with direct-differential absorption spectroscopy are efficient tools to monitor in situ stratospheric H₂O andCH₄ with a good precision error (a few percents), a high temporal resolution (ranging from 10 ms to 1 s), a large dynamic range in the concentration measurements (four orders of magnitude) and a high selectivity in the analyte species. To illustrate the capability of laser probing technique, we report balloonborne H₂Oand CH₄ simultaneous measurements obtained on October 2001 atmidlatitudes (43° N). The H₂O vertical profile achieved with the lasersensor in the lower stratosphere is compared with the H₂O data yielded by a balloonborne frost-point hygrometer. The total hydrogen mixing ratio in the lower stratosphere, 2[CH₄] + [H₂O], appears to beconstant at 7.5 ± 0.1 ppmv. Nevertheless, an unexpected largedehydration of 0.5 ppmv was detected by both the laser sensor and thehygrometer between 16 km and 23 km. We suspect the occurrence of a tropicalair intrusion into mid-latitudes. We support this interpretation using a high-resolution advection model for potential vorticity.     

青藏高原红原站平流层下部重力波观测特征分析

利用位处青藏高原的红原探空站2008年5月垂直高分辨率的无线电探空资料分析了其上空下平流层(19～26 km)重力波的波动特性.结果表明:重力波的垂直波长主要集中在2～4 km之间,平均值约为2.9 km;水平波长主要集中在100～600 km之间,平均值约为311 km;固有频率主要集中在1.5f～3.5f(f为科氏...     

Heterogeneous Chemistry and the O3 Budget in the Lower Mid-Latitude Stratosphere

A photochemical box model including a detailed heterogeneous chemistrymodule has been used to analyze in detail the effects of temperature andaerosol surface area on odd oxygen production/depletion in the lowerstratosphere at 30° S. Results show that for background aerosolloading, the hydrolysis of BrONO₂ and N₂O₅are most important atall temperatures studied except when the temperature falls below about205 K, when ClONO₂ hydrolysis becomes most important. Thisprocessing leads to removal of active nitrogen to form nitric acid andenhancement of HO_x, BrO_x, ClO_x levels. Detailed O₃ budgets asa function of temperature are presented showing how ozone loss andproduction terms vary with changes in stratospheric sulfate aerosol loadingfor the individual families. For (most) aerosol loading levels, thelargest ozone losses occurred at warmer temperatures due to the strongtemperature dependence of the NO_x ozone-destroying reactions. Theexception to this occurred for the conditions representative of volcanicloading, which showed a strong increase in ozone destruction due toincreases in destruction from the ClO_x and HO_x families.The ozoneproduction term k[NO][HO₂] did not show a strong dependence oneithertemperature or aerosol loading, due to the offsetting effect of reducedNO_xand increased HO_x concentrations.     

The Upper Stratospheric Ozone Budget: An Update of Calculations Based on HALOE Data

On the basis of data obtained by the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) box model calculations are performed to investigate the ozone budget in the upper stratosphere. The HALOE data comprise measurements of major source gases and key chemical species involved in the ozone destruction cycles. In comparison to earlier calculations using version 17 of the HALOE data, the calculated ozone destruction rate increases when the updated data version 18 is used. However, as with the previous study using version 17 of the HALOE data, no evidence for a significant model ozone deficit is found.     

赤道低平流层纬向风垂直切变与对流层环流及东亚季风的关系

在以赤道低平流层纬向风垂直切变为依据划分平流层QBO位相的基础上，讨论了赤道低平流层纬向风QBO与对流层环流及东亚季风的关系。结果表明：强冬季风和弱夏季风对应着赤道低平流层纬向风的东风切变位相，强夏季风和弱冬季风对应着赤道低平流层西风切变位相，赤道低平流层纬向风QBO对对流层环流有一定影响，冬春季节平流层与对流层的相互作用比夏秋季节明显。     

On the Temporal and Spatial Structure of Troposphere-to- Stratosphere Transport in the Lowermost Stratosphere over the Asian Monsoon Region during Boreal Summer

This study produced a novel characterization of the troposphere-to-stratosphere transport(TST) over the Asian monsoon region during boreal summer,using a comprehensive analysis of 60-day backward trajectories initialized in the stratosphere.The trajectory datasets were derived from the high-resolution Lagrangian particle dispersion model(FLEXPART) simulation driven by the wind fields acquired from the National Center for Environmental Prediction(NCEP).The results indicate that the distribution of residence time(tTST) of tropopause-crossing trajectories in the lowermost stratosphere represents a horizontal signature of the Asian summer monsoon.Vertically,the distribution of tTST can be roughly separated into two layers:a consistent lower layer with tTST <5 days forming a narrow band,corresponding to a layer～3 km thick following the location of the tropopause,and an upper layer at a larger distance from the local tropopause.The maximum residence time was～20 days,especially within the Asian high anticyclone consistent with its confinement effects.In general,the overall geographical distribution of dehydration points was not coincident with the location of tropopause crossing.TST trajectories,which were initialized in the stratosphere,underwent their Lagrangian cold points mostly in the tropics and subtropics 1-4 days after the TST event;they were characterized by a wide range of temperature differences,with a mean value of 3-12 K.The vertical extent of the influence of tropospheric intrusion on the Asian monsoon region in the stratosphere exhibited a peak at～16.5-18.5 km,and the uppermost height was～21 km.     

On the Nonlinear Response of Lower Stratospheric Ozone to NO_x and ClO_x Perturbations for Different CH_4 Sources

The impact of sulfate aerosol, ClO2 and NOx perturbations for two different magnitudes of CH4 sources on lower stratospheric ozone is studied by using a heterogeneous chemical system that consists of 19 species belonging to 5 chemical families (oxygen, hydrogen, nitrogen, chlorine and carbon). The results show that the present modeled photochemical system can present several different solutions, for instance, periodic states and multi-equilibrium states appearing in turn under certain parameter domains, through chlorine chemistry and nitrogen chemistry together with sulfate aerosol as well as the increasing magnitude of CH4 sources. The existence of catastrophic transitions could produce a dramatic reduction in the ozone concentration with the increase of external sources.     

平流层-对流层相互作用的多尺度过程特征及其与天气气候关系——研究进展

在过去5年中,在国家自然科学基金委员会和中国科学院的项目支持下,针对以大气上下层相互作用中的多时空尺度过程特征及其与天气气候的关系为主要关注内容,开展了几个方面的研究。本文介绍其中的一些主要进展与结果,包括:(1)平流层臭氧的探测与分析研究;(2)平流层－对流层质量交换(STME)与对流层顶特征研究;(3)中层大气多尺度波动特征研究;(4)大气辐射传输和中层大气卫星临边遥感新方法研究。     

Dynamic Seasonal Transition from Winter to Summer in the Northern Hemisphere Stratosphere

This study applied the modified spatial simi- larity coefficient method to define the seasonal transition （ST） from winter to summer in the extratropical strato- sphere of the Northern Hemisphere. The features of the ST were examined using European Centre for Medium- Range Weather Forecasts （ECMWF） Interim reanalysis data; and the results showed that the time and duration of the ST, which is affected by the activity of planetary waves （PW） in the stratosphere, largely depended on the geophysical locations. This study also investigated the interannual variability of the ST and its relationship with stratospheric sudden warming （SSW） and the qua- si-biennial oscillation （QBO）. It was shown that the late-onset SSW events （after 22 January） are close to the start of the ST. An easterly （westerly） QBO hastens （de- lays） the onset of the ST in high and low latitudes, whereas it delays （hastens） the ST in midlatitudes. The duration of the ST is significantly affected by the QBO. The influence of SSW and the QBO have different sig- nificance in different latitudes, so they are both important and irreplaceable factors.     

冬季北半球平流层季节内振荡与对流层季节内振荡的关系

通过平流层大气ISO与对流层大气ISO的比较分析,发现在中高纬地区平流层大气ISO与对流层大气ISO有着许多相同点.北半球冬半年平流层大气环流主要低频模态也可认为是北极涛动(AO),其空间分布的主要特征为; 高纬度地区与中低纬度地区为反位相变化,北极地区附近具有最大的变化值; 其季节内振荡的正位相对应于AO增强,负位相对应于AO减弱.北半球冬半年平流层100 hPa 和70 hPa 位势高度场的低频遥相关分析表明,北极地区(概指北纬60°N以北)和北半球其他大部分地区呈负相关,北极涛动扮演了非常重要的角色.同时,北半球冬半年平流层的主要低频波列是从欧亚大陆中部到西北太平洋,并且由纬向型低频波列(欧亚大陆-西伯利亚-太平洋)和经向型低频波列(欧亚大陆-北极-太平洋)共同构成.平流层30 hPa 和对流层500 hPa 上经过带通滤波(15～90 d)位势高度场的EOF第一主分量的形势有十分类似的特征,它们对应的时间系数序列有显著的延迟相关关系.因此可以认为,北半球平流层大气ISO的变化要先于对流层大气,在滞后35 d 左右其相关系数达到最大.大气环流模式(SAMIL)的数值模拟试验结果也表明,平流层的低频扰动可以在14 d 之后便在对流层500 hPa上激发出低频响应,其谱峰在30 d 左右.这进一步表明,通过大气季节内振荡,平流层的异常可以影响到对流层.     

Observed Long- and Short-lived North Atlantic Oscillation Events: Role of the Stratosphere

Utilizing three different sets of reanalysis data, this study examines the long-and short-lived observed positive North Atlantic Oscillation(NAO) events(referred to as NAO+_LE and NAO+_SE) and long-and short-lived observed negative NAO events(referred to as NAO-_LE and NAO-_SE). Composite results indicate that the NAO-like circulation anomalies associated with the long-lived NAO events can reach the stratosphere, while they are primarily confined to the tr...