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1.
Available data on halogenated molecules in the stratosphere will be reviewed. Presently vertical profiles of CFCl3 and CF2Cl2 in the stratosphere exist to 50 km altitude. Only measurements in the lower stratosphere are reported for the other major halocarbons, CCl4 and CH3Cl. Profiles of the product species ClO, Cl, HCl, and HF exist to about 35 km.Comparison with theoretical profiles from 1-D models shows generally good agreement except for ClO where the earliest measured concentrations exceed the calculated ones considerably. 相似文献
2.
A photochemical-transport two-dimensional model has been used to assess the impact of a projected fleet of high-speed stratospheric aircraft using different emissions scenarios. It is shown that the presence in the background atmosphere of nitric acid trihydrate aerosols is responsible for a lower stratospheric denoxification in addition to that caused by the sulfate aerosol layer. This has the effect of further decreasing the relative role of the odd nitrogen catalytic cycle for ozone destruction, so that the lower stratosphere is primarily controlled by chlorine species. The effect of aircraft injection of nitric oxides is that of decreasing the level of ClO, so that the lower stratospheric ozone (below about 20–25 km altitude) increases. The net effect on global ozone is that of a small increase even at Mach 2.4, and is enhanced by adopting emission scenarios including altitude restriction at 15 or 18 km. Reductions of the emission index (EI) of nitric oxides below relatively small values (about 15) are shown to reduce the aircraft-induced ozone increase, because of the associated smaller decrease of ClO. This conclusion is no more valid when the emission index is raised at the present values (about 45). 相似文献
3.
J. K. Angell 《Pure and Applied Geophysics》1980,118(1):378-386
Examined are temperature and ozone variations in the Northern Hemisphere stratosphere during the period 1958–77, as estimated from radiosondes rocketsondes, ozonesondes, and Umkehr measurements. The temperature variation in the low tropical stratosphere is a combination of the variation associated with the quasi-biennial oscillation, and a variation nearly out of phase with the pronounced 3-yearly temperature oscillation (Southern Oscillation) present in the tropical troposphere since 1963. Based on radiosonde and rocketsonde data, the quasibiennial temperature oscillation can be traced as high as the stratopause, the phase varying with both height and latitude. However, the rocketsonde-derived temperature decrease of several degrees Celsius in the 25–55 km layer of the Western Hemisphere between 1969 (sunspot maximum) and 1976 (sunspot minimum) is not apparent in high-level radiosonde data, so that caution is advised with respect to a possible solar-terrestrial relation.There has been a strong quasi-biennial oscillation in ozone in the 8–16 km layer of the north polar region, with ozone minimum near the time of quasi-biennial west wind maximum at a height of 20 km in the tropics. A quasi-biennial oscillation in ozone (of similar phase) is also apparent from both ozonesonde data and Umkehr measurements in 8–16 and 16–24 km layers of north temperate latitudes, but not higher up. Both measurement techniques also suggest a slight overall ozone decrease in the same layers between 1969 and 1976, but no overall ozone change in the 24–32 km layer. Umkehr measurements indicate a significant 6–8% increase in ozone amount in all stratospheric layers between 1964 and 1970, and in 1977 the ozone amount in the 32–46 km layer was still 4% above average despite the predicted depletion due to fluorocarbon emissions. The decrease in ozone in the 32–46 km, layer of mid latitudes following the volcanic eruptions of Agung and Fuego is believed to be mostly fictitious and due to the bias introduced into the Umkehr technique by stratospheric aerosols of volcanic origin. Above-average water vapor amounts in the low stratosphere at Washington, DC, appear closely related to warm tropospheric temperatures in the tropics, presumably reflecting variations in strength of the Hadley circulation. 相似文献
4.
利用1992～2005年卤素掩星试验（HALOE）的观测资料分析了中国上空平流层的几种微量气体（NO, NO2, HF, HCl, CH4, H2O 和O3）混合比的垂直分布和变化趋势,以期为研究平流层的辐射和化学过程提供一些有用的数据. 文中除给出我国上空平流层各高度上平均的各种微量气体的含量外,还给出青藏高原上空这些微量气体的含量. 分析结果表明,平流层各种微量气体混合比的垂直分布有其不同的特征,在对流层上层到平流层底部各种微量气体的混合比分布和季节变化与平流层相比有明显的差异;分析结果还表明,这些微量气体的季节变化、准两年周期振荡和长期变化趋势都很明显,并且在平流层的不同高度上它们的变化趋势是不相同的. 在平流层中层,NO, NO2, HCl 和H2O 混合比在1998年以前都是增加而后则是明显下降的,但O3相反,在1998年以前明显减少,1998年后其减少的趋势不明显. 这表明,近年来平流层中层这些微量气体的减少使得它们对臭氧的破坏有所缓解. 但在平流层下层,臭氧的耗损仍然很明显. 相似文献
5.
Josef Podzimek 《Pure and Applied Geophysics》1983,121(4):611-632
In the light of new measurements of small aerosol particles in the lower stratosphere, some of the old investigations—which
were only published in part in scientific journals—are reviewed and compared. The discussion focuses on whether the Aitken
nuclei (AN) size distribution up to 20 km can be described by Junge’s or log-normal density functions and under what circumstances
one can find a bimodal distribution of these particles. The ion flow in correlated to the stratospheric pollution (intercept
with the jet aircraft, volcanic activity) and is, in mean, directly proportional to the aircraft altitude in the undisturbed
lower stratosphere.
Note: The GCCPR, Univ. Missouri at Rolla, reports quoted in the article can be obtained from the author. 相似文献
6.
The stratosphere holds a variety of particulates like polar stratospheric clouds (PSCs) and sulphate aerosols which catalyse chemical reactions. These reactions cause changes in the composition of the stratosphere, including the redistribution of active chlorine which might lead to ozone destruction. As a result during recent years a lot of effort has been directed towards the quantification of the uptake of trace gases like ClONO2, HCl, etc. into these particulates. However, it has been observed that many of the two and three dimensional models used in such studies are constrained by the lack of adequate rate constant data. This paper describes a theoretical approach to estimate the reaction rate constants for 23 gases on both types of polar stratospheric clouds (type I and II). It is found that for gases like N2O5, ClONO2 and HCl, diffusional uptake is important and contributes significantly to the heterogeneous reaction rate. A complete Lennard-Jones calculation is used to accurately compute the trace gas diffusion coefficients. 相似文献
7.
We have studied the effects on the ozone concentration and surface temperature, of perturbations in the atmospheric content of nitrous oxide, methane, carbon dioxide and chlorofluorocarbons (CFC). The sensitivity study has been carried out with a radiative-convective-photochemical model. The doubling of carbon dioxide concentration has the effect of warming the troposphere and cooling the stratosphere. As a result of this cooling, the change of ozone columnar density produced by 10 ppb of chlorine amount to 9.3% as compared to –10.9% obtained without temperature feedback. Perturbation in nitrous oxide correspond to an increase in NO
x
of the stratosphere with consequent ozone reduction while doubling the methane concentration correspond to a slight increase in columnar density. The effect of the increased methane concentration in the stratosphere contributes to reduce the effect of CFC due to the enhanced formation of HCl. The perturbation of these two minor constituents appreciably increase the greenhouse effect to 2.30 from 1.67°, obtained when carbon dioxide alone is considered. 相似文献
8.
本文利用序列回归分析、对比分析和个例分析法分析了火山活动对热带高空大气的温度效应. 主要结论为：火山活动影响最显著的高度是平流层70 hPa约22 km高空,由此高度向上或向下,火山活动的影响都逐渐减小;火山活动将引起平流层大气升温、对流层大气降温,其分界线大致位于对流层顶300 hPa附近;火山活动对于热带70 hPa高空温度距平变化的影响超过了总方差的457%;单独考察几次强火山活动（如阿贡火山、皮纳图博火山和厄尔奇冲火山等）的温度效应表明,在热带地区强火山爆发后的20个月内,对热带高空温度的影响超过了其距平变化的80%！成为该时段高空温度变化的决定性因素. 相似文献
9.
A new determination of stratospheric methane from 22 km to 35 km altitude with implications on the abundance of this constituent at greater heights is presented. Previous measurements, some of which showed large discrepancies with currently admitted values, have been reinterpreted and brought into agreement. The results are in contradiction according to present theories with thein situ determined CH4 abundances at the upper edge of the stratosphere. Implications on the vertical transport coefficient used in one dimensional models are discussed. 相似文献
10.
Inertial gravity wave parameters for the lower stratosphere from radiosonde data over China 总被引：2，自引：0，他引：2
Characterization of gravity wave(GW)parameters for the stratosphere is critical for global atmospheric circulation models.These parameters are mainly determined from measurements.Here,we investigate variation in inertial GW activity with season and latitude in the lower stratosphere(18-25 km)over China,using radiosonde data with a high vertical resolution over a 2-year period.Eight radiosonde stations were selected across China,with a latitudinal range of 22°-49°N.Analyses show that the GW energy in the lower stratosphere over China has obvious seasonal variation and a meridional distribution,similar to other regions of the globe.The GW energy is highest in winter,and lowest in summer;it decreases with increasing latitude.Velocity perturbations with longitude and latitude are almost the same,indicating that GW energy is horizontally isotropic.Typically,85%of the vertical wavelength distribution is concentrated between elevations of 1 and 3 km,with a mean value of 2 km;it is almost constant with latitude.Over 80%of all the horizontal wavelengths occur in the range 100-800 km,with a mean value of 450km;they show a weak decrease with increasing latitude,yielding a difference of about 40 km over the 22°-49°N range.The ratio of horizontal wavelength over vertical wavelength is about 200:1,which implies that inertial GWs in the lower stratosphere propagate along nearly horizontal planes.Ratios of their intrinsic frequency to the Coriolis parameter decrease with increasing latitude;most values are between 1 and 2,with a mean value of 1.5.Study of the propagation directions of GW energy shows that upward fractions account for over 60%at all stations.In contrast,the horizontal propagation direction is significantly anisotropic,and is mainly along prevailing wind directions;this anisotropy weakens with increasing latitude. 相似文献
11.
南极地区重力波活动有大量报道,相对而言,北极地区重力波的研究还很少.本文利用极区Ny-Alesund站点（78.9°N,11.9°E）无线电探空仪从2012年4月1日到2017年3月31日共5年的观测数据,统计分析了北极地区低平流层惯性重力波的特征.观测显示,月平均纬向风在20 km以下盛行东向风,再随着高度增加,逐渐呈现出半年振荡现象.对流层顶高度在5~13 km范围内变化,其月平均高度显示出年循环,最高出现在夏季,约为10 km,最低出现在冬季,约为8.5 km.对流层和低平流层月平均温度都显示出明显的年周期变化,这与中低纬度观测结果有所不同.结合Lomb-Scargle谱分析和矢端曲线方法,估算了准单色惯性重力波参数.个例研究表明,低平流层惯性重力波呈现出远离源区的自由传播性质.统计结果显示,惯性重力波的水平和垂直波长分别集中在50~450 km和1~4 km范围内,本征频率集中在1~2.5倍惯性频率间,这些值都比中低纬度观测值稍小.垂直方向本征相速度主要集中在-0.3~0 m·s-1,而纬向和经向本征相速度集中在-40~40 m·s-1之间.在5年的观测中,大约91.5%的惯性重力波向上传播.在冬季和早春,由于极地平流层极涡活动,激发出向下传播的惯性重力波,因此,向下传播的比例上升到相应月份的20%左右.由于低层大气盛行的东向风的滤波效应,低平流层大部分惯性重力波向西传播.波能量呈现出明显的年周期变化,最大值在冬季、最小值在夏季,与北半球中低纬度观测结果一致,表明北半球重力波活动普遍冬季强、夏季弱. 相似文献
12.
A. N. Gruzdev 《Geomagnetism and Aeronomy》2014,54(5):633-639
Using spectral, cross-spectral, and regression methods, we analyzed the effect of the 11-year cycle of solar activity on the ozone content in the stratosphere and lower mesosphere via satellite measurement data obtained with the help of SBUV/SBUV2 instruments in 1978–2003. We revealed a high coherence between the ozone content and solar activity level on the solar cycle scale. In much of this area, the ozone content varies approximately in phase with the solar cycle; however, in areas of significant gradients of ozone mixing ratio in the middle stratosphere, the phase shift between ozone and solar oscillations can be considerable, up to π/2. This can be caused by dynamical processes. The altitude maxima of ozone sensitivity to the 11-year solar cycle were found in the upper vicinity of the stratopause (50–55 km), in the middle stratosphere (35–40 km), and the lower stratosphere (below 25 km). Maximal changes in ozone content in the solar cycle (up to 10% and more) were found in winter and spring in polar regions. 相似文献
13.
Paul J. Squillace James F. Pankow Jack E. Barbash Curtis V. Price John S. Zogorski 《Ground Water Monitoring & Remediation》1999,19(1):67-74
Water samples collected for the determination of volatile organic compounds (VOCs) are often preserved with hydrochloric acid (HCl) to inhibit the biotransformation of the analytes of interest until the chemical analyses can he performed. However, it is theoretically possible that residual free chlorine in the HCl can react with dissolved organic carbon (DOC) to form chloroform via the haloform reaction. Analyses of 1501 ground water samples preserved with HCl from the U.S. Geological Survey's National Water-Quality Assessment Program indicate that chloroform was the most commonly detected VOC among 60 VOCs monitored. The DOC concentrations were not significantly larger in samples with detectable chloroform than in those with no delectable chloroform, nor was there any correlation between the concentrations of chloroform and DOC. Furthermore, chloroform was detected more frequently in shallow ground water in urban areas (28.5% of the wells sampled) than in agricultural areas (1.6% of the wells sampled), which indicates that its detection was more related to urban land-use activities than to sample acidification. These data provide strong evidence that acidification with HCl does not lead to the production of significant amounts of chloroform in ground water samples. To verify these results, an acidification study was designed to measure the concentrations of all trihalomethanes (THMs) that can form as a result of HCl preservation in ground water samples and to determine if ascorbic acid (C6 H8 O6 ) could inhibit this reaction if it did occur. This study showed that no THMs were formed as a result of HCl acidification, and that ascorbic acid had no discernible effect on the concentrations of THMs measured. 相似文献
14.
S. S. Prasad 《Annales Geophysicae》1995,13(3):296-304
This paper discusses new potential reactions of chlorine-bearing anions (negative ions) in the upper stratosphere. These reactions are then applied to the negative-ion chemistry following the injection of an electron cloud of very high density, of the order of 106-107 e- cm−3, in the 40-45-km region. The idea is to evaluate the recently proposed scheme to mitigate ozone depletion by converting the reactive chlorine atoms at these altitudes into Cl- ions which are unreactive towards ozone, i.e., electron scavenging of Cl. We find that the previously neglected photodetachment from Cl- is fast. For an overhead sun, this process may have a rate coefficient of 0.08 s−1 when multiple scattering is included. The rate could be even higher, depending on the ground albedo. Switching reaction between Cl-·H2O and HCl might lead to the formation of Cl-·HCl anion. Possible reactions of Cl-·H2O and Cl-·HCl with O atoms could produce ClO- and Cl-2. The production of ClO- in this manner is significant because Cl- having a high photodetachment rate constant would be regenerated in the very likely reactions of ClO- with O. When these possibilities are considered, then it is found that the chlorine anions may not be the major ions inside the electron cloud due to the rapid photodetachment from Cl-. Furthermore, in such a cloud, there may be the hazard that the Cl--Cl-·H2O-ClO--Cl- cycle amounts to catalytic destruction of two O atoms. Thus, the scheme could be risky if practised in the altitude region where atomic oxygen is an important constituent. Similar conclusions apply even if the ClO- species forms ClO-3 by three-body association with O2, instead of reacting with O. It must be emphasized that the present study is speculative at this time, because none of the relevant reactions have been investigated in the laboratory as yet. Nevertheless, it is very safe to say that the scheme of ozone preservation by electron scavenging of the upper stratospheric Cl is much less certain than implied in the studies reported by its original proponents, because those studies neglected the photodetachment from Cl- and made the highly unlikely assumption that the Cl-·H2O anion neither photodissociates nor reacts any further. The situation at the lower altitudes could be even more complex due to the formation of large cluster ions and the ion-induced aerosol formation. The lower atmospheric situation, therefore, requires much more study. The uncertainties in the scavenging scheme due to the electrostatic repulsion in the cloud should also be addressed. Despite the uncertainties about its environmental engineering usefulness, the emerging technology for artificial creation of plasmas, with any desired density and charge in the stratosphere, could have significant pure scientific values in the studies of stratospheric ion chemistry and ion-induced aerosol formation. Such studies have perennially suffered from the extremely low densities of the naturally occurring plasma. 相似文献
15.
M. I. Beloglazov V. M. Demkin A. A. Krasilnikov L. M. Kukin Yu. Yu. Kulikov V. G. Ryskin V. N. Shanin 《Geomagnetism and Aeronomy》2010,50(2):256-262
As a result of the long-term observations lead in region of Kola Peninsula, connection between character of variations of
the ozone content in a stratosphere of Arctic regions and behavior and structure of a winter polar vortex is established.
During winter seasons with well developed cyclone and duration of stable existence not less than 1.5–2 months were observed
extremely low ozone number density at heights 20–25 km connected, apparently, with its chemical destruction. On the other
hand, during disturbances of the vortex, accompanied strong stratospheric warming, was registered almost double increase of
ozone amount in a high-altitude interval from 20 up to 40 km. Comparison of results of ground-based microwave monitoring of
an ozone layer to data of the satellite instrument EOS MLS installed on satellite AURA is lead. In most cases comparison has
shown satisfactory within the limits of an error of measurements coincidence of results. However in conditions of atmospheric
disturbances when arose significant spatial heterogeneity, the discrepancy of results of comparison was marked. The possible
reasons which cause the detected disagreement in results are discussed. 相似文献
16.
青藏高原为亚洲季风区的典型代表区域,研究其水汽进入平流层的过程和机理对认识全球气候和大气环境变化具有一定的现实意义. 本文基于中尺度气象模式(WRF)的模拟输出结果(2006年8月20日至8月26)驱动拉格朗日大气输送模式FLEXPART,通过追踪并解析气块的三维轨迹以及温度、湿度等相关物理量的相关变化特征,初步分析了夏季青藏高原地区近地层-对流层-平流层的水汽输送特征. 研究结果表明,源于高原地区近地层的水汽在进入平流层的过程中受南亚高压影响下的大尺度环流和中小尺度对流的共同影响.首先,在对流抬升作用下,气块在短时间内(24 h)可抬升到9~12 km的高度,然后在南亚高压闭合环流影响下,相当部分气块在反气旋的东南侧穿越对流层顶进入平流层中,并继续向低纬热带平流层输送,进而参与全球对流层-平流层的水汽循环过程. 在对流抬升高度上气块位置位于高原的西北侧,然而气块拉格朗日温度最小值主要分布于高原南侧,两个位置上气块的平均位温差值可达15~35 K,这种显著的温度差异将导致气块进入平流层时"脱水". 比较而言,夏季青藏高原地区近地层水汽进入平流层的多寡主要和大尺度汽流的垂直输送有关,而深对流的作用相对较弱. 相似文献
17.
David A. Kring H. Jay Melosh Donald M. Hunten 《Earth and Planetary Science Letters》1996,140(1-4):201-212
Asteroids and comets that are vaporized during hypervelocity impact events can inject large masses of S into the stratosphere where it can potentially affect the radiation budget of the Earth, alter the chemistry of the ozone layer, and eventually be converted to sulfuric acid rain. Relatively small carbonaceous asteroids, 0.3 km in diameter, contain 5 times more S than the entire modern stratosphere and these objects hit the Earth at an average rate of 1 per 10,000 years. Larger impact events, capable of injecting 1015 g of S into the stratosphere, occur at an average rate of 1 per 1 million years. Calculations indicate there is sufficient O and H in the vapor plumes of most impact events to convert the S to sulfuric acid aerosols. If this conversion occurs, then the larger impact events could depress mean surface temperatures by more than 2°C for 3 years or longer. 相似文献
18.
Although stratosphere penetrating volcanic eruptions have been infrequent during the last half century, periods have existed in the last several hundred years when such eruptions were significantly more frequent. Several mechanisms exist for these injections to affect stratospheric minor constitutent chemistry, both on the long-term average and for short-term perturbations. These mechanisms are reviewed and, because of the sensitivity of current models of stratospheric ozone to chlorine perturbations, quantitative estimates are made of chlorine injection rates. It is found that, if chlorine makes up as much as 0.5 to 1% of the gases released and if the total gases released are about the same magnitude as the fine ash, then a major stratosphere penetrating eruption could deplete the ozone column by several percent. The estimate for the Agung eruption of 1963 is just under 1% an amount not excluded by the ozone record but complicated by the peak in atmospheric nuclear explosions at about the same time. The long-term contribution to stratospheric CIX by volcanic eruptions is estimated as 0.1 ppbv for the period 1900–60 and 1 ppbv for the much more volcanically active period 1780–1840. All of the estimates are subject to large uncertainties, perhaps a factor of 2 or 3 on the high side and a factor of 10 or more on the low side.Paper presented at the IAGA/IAMAP Joint Assembly, Seattle, WA, U.S.A., August 1977. 相似文献
19.
Volcanic gases such as SO 2, H 2S, HCl and COS emitted during explosive eruptions significantly affect atmospheric chemistry and therefore the Earth's climate. We have evaluated the dependence of volcanic gas emission into the atmosphere on altitude, latitude, and tectonic setting of volcanoes and on the season in which eruptions occurred. These parameters markedly influence final stratospheric gas loading. The latitudes and altitudes of 360 active volcanoes were compared to the height of the tropopause to calculate the potential quantity of volcanic gases injected into the stratosphere. We calculated a possible stratospheric gas loading based on different volcanic plume heights (6, 10, and 15 km) generated by moderate-scale explosive eruptions to show the importance of the actual plume height and volcano location. At a plume height of 15 km for moderate-scale explosive eruptions, a volcano at sea level can cause stratospheric gas loading because the maximum distance to the tropopause is 15–16 km in the equatorial region (0–30°). Eruptions in the tropics have to be more powerful to inject gas into the stratosphere than eruptions at high latitudes because the tropopause rises from ca. 9–11 km at the poles to 15–16 km in the equatorial region (0–30°N and S). The equatorial region is important for stratospheric gas injection because it is the area with the highest frequency of eruptions. Gas injected into the stratosphere in equatorial areas may spread globally into both hemispheres. 相似文献
20.
《Journal of Atmospheric and Solar》2008,70(1):13-40
The solid and liquid particles which constitute polar stratospheric clouds (PSCs) are of manifold importance to the meteorology of the stratosphere. The heterogeneous reactions which take place on and within these particles release halogens from relatively inert reservoir species into forms which can destroy ozone in the polar spring. In addition, solid PSC particles are instrumental in the physical removal of nitrogen oxides (denitrification) and water (dehydration) of regions of the polar stratosphere. Denitrification, in particular, allows extended ozone destruction by slowing the conversion of chlorine radicals back into reservoir species.We review the historical development of PSC studies, with particular emphasis on results from the last decade, encompassing developments in observations, in laboratory experiments, and in theoretical treatments. The technical challenge of measuring sufficient of the parameters describing any given PSC, to allow its microphysics to be understood, has driven forward balloon-borne, aircraft, and satellite instrumentation. The technical challenge of finding suitable laboratory proxies for PSCs, in order to observe the microphysics under controlled conditions, has resulted in a wide variety of experimental designs, some of which maximise the probability of observing phase change, others which mimic the surface–volume ratios of PSCs more closely. The challenge to theory presented by PSCs has resulted in improvements in the thermodynamics of concentrated inorganic solutions of volatile compounds, and a new general theory of freezing of water ice from concentrated aqueous solutions. Of the major processes involving PSCs, heterogeneous reaction probabilities for ternary HNO3/H2SO4/H2O solutions, and heterogeneous freezing to produce nitric-acid hydrates, are the least well understood. 相似文献