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1.
The paper discusses the potential effects on the ozone layer of gases released by the engines of proposed high altitude supersonic aircraft. The major problem arises from the emissions of nitrogen oxides which have the potential to destroy significant quantities of ozone in the stratosphere. The magnitude of the perturbation is highly dependent on the cruise altitude of the aircraft. Furthermore, the depletion of ozone is substantially reduced when heterogeneous conversion of nitrogen oxides into nitric acid on sulfate aerosol particles is taken into account in the calculation. The sensitivity of the aerosol load on stratospheric ozone is investigated. First, the model indicates that the aerosol load induced by the SO2 released by aircraft is increased by about 10–20% above the background aerosols at mid-high latitude of the Northern Hemisphere at 15 km for the NASA emission scenario A (the NASA emission scenarios are explained in Tables I to III). This increase in aerosol has small effects on stratospheric ozone. Second, when the aerosol load is increased following a volcanic eruption similar to the eruption of El Chichon (Mexico, April 1982), the ozone column in spring increases by as much as 9% in response to the injection of NO x from the aircraft with the NASA emission scenario A. Finally, the modeled suggests that significant ozone depletion could result from the formation of additional polar stratospheric clouds produced by the injection of H2O and HNO3 by the aircraft engines.  相似文献   

2.
使用国家气候中心大气环流模式BCC_AGCM2.1的30年模拟试验资料,对平流层纬向环流场、高空急流、极涡及爆发性增温过程进行了数值模拟研究,并使用欧洲中期天气预报中心(ECMWF)和美国国家环境预报中心(NCEP)的再分析资料对模式输出结果进行了对比、分析。结果表明:(1) 在观测海温、二氧化碳、气溶胶等外强迫地驱动下,BCC模式能够很好地再现出与再分析资料一致的平流层纬向平均风场、温度场的分布特征和季节变化过程;模拟得到的温度廓线和高空急流与再分析资料的主要差别出现在南、北半球冬季的中高纬度地区;模拟得到的平流层温度普遍偏低,主要的差异位于对流层顶区域和平流层高层。(2) 模拟的对流层上层的副热带急流位置偏南、强度也偏弱,而平流层中的绕极极夜急流则位置偏北、强度更大。这样的急流分布特征使模拟的行星波向赤道的波导更强,向极的波导偏弱;同时由于模式中本身可以形成的行星波就比再分析资料弱,因此导致模拟结果中北半球冬季的平流层极涡更加稳定、极区温度更低。(3) BCC模式对于平流层极涡的季节变化特征模拟得较好,但对强极涡扰动过程,即北半球冬季的平流层爆发性增温(SSW)事件则模拟效果不佳,不论是增温事件出现的频率,还是增温的时间、强度,模拟结果和再分析资料都还存在一定偏差,需要在今后的工作中逐步改善。  相似文献   

3.
Vertical profiles of aerosol were measured in February 1993, and January - March 1995 using balloon-borne particle counters released from Kiruna, Sweden. Condensation nuclei (CN) and aerosol with radii 0.15 - 10.0 µm were measured in 8-12 size classes. The three flights in 1993 were within the polar vortex. Temperatures were below polar stratospheric cloud (PSC) threshold temperatures on one flight and a thin PSC was observed. The volcanic aerosol in the 1993 vortex was similar to that in 1992. In 1993, surface areas were 10 - 20 µm2 cm-3 and volumes 1 - 3 µm3 cm-3. In 1995 three of five flights were within the polar vortex. The volcanic aerosol had decreased to 3 - 7 µm2 cm-3 and 0.1 - 0.4 µm3 cm-3. The top of the volcanic aerosol layer in both years was near 500 K potential temperature (~20 km). A thick nitric acid and water PSC was observed in January 1995. In the thickest region of this PSC nearly all CN were observed to be activated, and surface areas of 5 - 10 µm2 cm-3 were calculated. The volumes observed in this PSC were closer to what would be expected for particles composed of nitric acid trihydrate than for ternary solution droplets. In 1993 the opposite was observed, the volumes in the thin PSC were closer to what would be expected for ternary solution droplets.  相似文献   

4.
Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H2O on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate the chemical and radiative impacts of an assumed 2 ppmv increase in H2O. The chemical effects of this H2O increase lead to an overall decrease of the total column ozone (TCO) by ~1% in the tropics and by a maximum of 12% at southern high latitudes. At northern high latitudes, the TCO is increased by only up to 5% due to stronger transport in the Arctic. A 2-ppmv H2O increase in the model's radiation scheme causes a cooling of the tropical stratosphere of no more than 2 K, but a cooling of more than 4 K at high latitudes. Consequently, the TCO is increased by about 2%--6%. Increasing stratospheric H2O, therefore, cools the stratosphere both directly and indirectly, except in the polar regions where the temperature responds differently due to feedbacks between ozone and H2O changes. The combined chemical and radiative effects of increasing H2O may give rise to more cooling in the tropics and middle latitudes but less cooling in the polar stratosphere. The combined effects of H2O increases on ozone tend to offset each other, except in the Arctic stratosphere where both the radiative and chemical impacts give rise to increased ozone. The chemical and radiative effects of increasing H2O cause dynamical responses in the stratosphere with an evident hemispheric asymmetry. In terms of ozone recovery, increasing the stratospheric H2O is likely to accelerate the recovery in the northern high latitudes and delay it in the southern high latitudes. The modeled ozone recovery is more significant between 2000--2050 than between 2050--2100, driven mainly by the larger relative change in chlorine in the earlier period.  相似文献   

5.
对流层气溶胶的直接气候效应对平流层的影响   总被引:1,自引:1,他引:0       下载免费PDF全文
通过WACCM-3模式中气溶胶光学厚度与卫星资料的对比发现,模式可以很好地再现全球气溶胶的主要分布特征,但在一些区域还存在数值上的差异。利用数值试验研究对流层气溶胶的直接气候效应对平流层气候的影响,结果表明:对流层气溶胶对平流层气候有明显影响,平流层化学过程在这一影响中起重要作用,而对流层气溶胶对平流层辐射的影响不是其直接气候效应对平流层影响的主要原因。其机制可能是对流层气溶胶改变对流层的辐射平衡,影响对流层的温度和大气环流,进而影响行星波的上传,使得平流层气候发生变化;影响区域主要位于高纬度和极地地区,南半球的变化比北半球大,温度变化最大达10 K,纬向风变化最大可达12 m/s,臭氧体积分数最多减少0.8×10-6。  相似文献   

6.
We present a theory for the formation of frozen aerosol particles in the Antarctic stratosphere, the coldest region of the Earth's stratosphere. The theory is applied specifically to the formation of polar stratospheric clouds. We suggest that the condensed ices are composed primarily of nitric acid and water with small admixtures of other compounds such as H2SO4 and HCl in solid solution. Our assumed particle formation mechanism is in agreement with the magnitude and seasonal behavior of the optical extinctions observed in the winter polar stratosphere. Physical chemistry and thermodynamic considerations suggest that at temperatures between about 200 and 185 K, stratospheric particulates are composed primarily of frozen nitric acid solutions with a composition near that of the trihydrate. Available data suggest the particles are amorphous solid solutions and not in the crystalline hydrate form. At lower temperatures (i.e., below the forst point of pure water) cirrus-like ice clouds can form.  相似文献   

7.
The first direct in situ measurements of the sulfuric acid contained in stratospheric aerosol particles were made using a novel balloon-based Ion Molecule Reaction Mass Spectrometer instrument (IMRMS) equipped with an aerosol vaporizer. The IMRMS method employed offers direct aerosol sulfuric acid measurements with high spatial resolution. The balloon flight took place on 23 October 1995 in middle latitudes (44°N) and reached a maximum altitude of 24 km. Measured molecular number densities of aerosol sulfuric acid decreased with increasing altitude from about 2.9 × 109 cm-3 at 15km altitude to about 2.4 × 108 cm-3 at 21 km. Corresponding mass mixing ratios are 2.5 and 0.6 ppbm, respectively. Calculated sulfuric acid mixing ratios from aerosol volumes inferred from aerosol size distribution measurements on the same balloon agree well with the IMRMS data using standard assumption aerosol composition.  相似文献   

8.
平流层爆发性增温及其影响研究进展   总被引:4,自引:3,他引:1  
杨光  李崇银  李琳 《气象科学》2012,32(6):694-708
平流层爆发性增温(stratospheric sudden warming,SSW)是冬季平流层大气环流结构的一种突变现象,在短时间内平流层中高纬度的温度、风和极涡都会发生剧烈变化。因此,SSW也就成为平流层大气环流及其变化研究的重要方面之一。在强SSW期间,高纬地区温度急剧升高,西风被东风取代,极涡几乎全部崩溃。SSW极大地影响着北半球对流层大气,甚至整个中高层大气,包括对平流层乃至中层大气微量气体分布的重要影响。随着临近空间飞行平台的研究应用,以及由此而提出的临近空间环境条件的保障问题,作为临近空间重要组成部分的平流层环流变化将更加引起人们的关注。本文就SSW的特征、发生机制、对上下层相互作用的重要影响,以及SSW与准两年振荡、ENSO等的密切关系和SSW的数值模拟等方面的研究工作,进行了回顾和总结。  相似文献   

9.
A chronology of stratospheric aerosol optical depth for the period 1671–1881 is derived from total lunar eclipse colors. It is compared with available proxy time series for the same period and with more refined data for more recent years. Contrary to previous speculations, the stratosphere from 1671 to 1881 seems to have been mostly undisturbed volcanically, with only two or three eruptions having injected into it truly significant amounts of aerosol-producing and climate-altering sulfur gases. It is confirmed that the full record for 1671–2000 shows a marked, though possibly quasiregular, ∼80 year periodicity in stratospheric aerosol optical depth, which appears also in polar ice-core acidity records and in volcanic eruption frequencies.  相似文献   

10.
The stratospheric ozone layer protects life on earth by preventing solar ultraviolet radiation from reaching the surface. Owing to the large population in the Northern Hemisphere and extreme ozone loss in the Arctic, changes in Arctic stratospheric ozone (ASO) and their causes have attracted broad attention recently. Using monthly mean data during the period 1980–2020 from MERRA-2, the relationship between the stratospheric polar vortex (SPV) and ASO, along with the relative contributions of chemical and dynamic processes associated with the SPV to changes in ASO, were examined in this study. Results showed that the ASO in March has a strong out-of-phase link with the strength of the SPV in March, with no obvious lead–lag correlations, i.e., an increase (decrease) in ASO corresponds to a weakened (strengthened) SPV. Further analysis suggested that the strong out-of-phase link between the SPV and ASO is related to changes in Brewer–Dobson circulation (BDC). Strong SPV events, accompanied by a low temperature condition and weakened upward propagation of planetary waves over the Arctic in the stratosphere, result in weakened BDC. The weakened downwelling at high latitudes tends to transport less ozone-rich air in the upper stratosphere at lower latitudes into the lower stratosphere at high latitudes, facilitating a decrease in ASO. The BDC's vertical velocity plays the dominant role in modulating ASO.摘要利用1980–2020年MERRA-2资料, 分析了平流层极涡 (Stratospheric polar vortex, SPV) 和北极臭氧 (Arctic stratospheric ozone, ASO) 的关系, 评估了与SPV相关的化学, 动力过程在其中的相对作用. 结果表明, 3月份ASO与同期SPV强度反相关最大. SPV-ASO二者反相关与平流层剩余环流 (Brewer-Dobson circulation, BDC) 变化密切相关. 强SPV伴随的北极平流层低温条件和行星波向上传播减弱, 导致BDC减弱, 减弱的BDC下沉支将低纬度平流层上层臭氧含量较低的空气输送到北极平流层低层, 从而导致ASO减少. BDC垂直速度在其中起主导作用.  相似文献   

11.
火山活动对气候的影响   总被引:7,自引:1,他引:7       下载免费PDF全文
李靖  张德二 《气象科技》2005,33(3):193-198
重大的火山喷发对气候的影响表现为地面温度降低,由于火山喷发存在季节、纬度和强度的差异,因此喷发物的空间分布特征不同,对辐射的影响也不同,降温出现的时间和降温的幅度不一致。中高纬喷发的火山主要影响发生喷发的半球,而中低纬的喷发可影响到全球,且影响时间较长;不同季节的火山喷发后,高纬度的温度响应较低纬明显,夏季的温度响应较冬季明显。有关火山活动对降水的影响目前已有了一些研究,但由于降水序列中火山信号较弱,同时还有ENSO等其他因子的影响,客观地分辨出火山的影响较复杂,目前尚无一致结论。  相似文献   

12.
The stellar occultation method has been successfully used in the past from orbiting observatories to measure concentrations of certain trace gases in the Earth's mesosphere. The greatly improved spectroscopic capabilities of the Hubble Space Telescope (HST) have prompted recent suggestions for its use to measure stratospheric C10. We examine this possibility along with that for other species relevant to the chemistry of the ozone layer. We conclude that stratospheric (as opposed to mesospheric) observations with HST are not practical, in part because of its orbital and pointing characteristics, but primarily because the high opacity of stratospheric ozone over most of the band-pass of the HST's most suitable spectrometer will obscure observation of other trace species, such as C10, having mixing ratios <10–3 that of ozone.  相似文献   

13.
平流层对对流层的作用是准确评估、预测对流层气候变化的一个重要方面。其中平流层成分尤其是臭氧的变化,可以改变平流层乃至对流层的辐射平衡,从而影响平流层、对流层的热动力过程。本文从辐射、动力2个角度介绍了平流层臭氧影响对流层气候变化的若干研究进展。平流层臭氧可以通过长短波辐射的方式对对流层大气造成辐射强迫,利用大气化学气候模式可以定量计算平流层臭氧变化引起的辐射强迫,但是辐射强迫的估算受模式中辐射传输模块本身缺陷的影响存在不确定性。动力方面,平流层臭氧变化产生的辐射效应可以改变温度的垂直和经向梯度,造成波折射指数的变化,进而影响平流层甚至对流层内波的折射与反射,通过上对流层下平流层区域内的波—流相互作用,对对流层气候产生影响。另外,南极臭氧损耗可通过大气环状模影响冬春季中高纬度对流层的天气气候,但是其影响的强度大小以及物理机制仍需进一步的确认。值得注意的是,北极平流层臭氧的变化与北半球中高纬度气候变化之间的关系相比南半球要更加复杂,需要更为深入的研究。  相似文献   

14.
利用观测和再分析资料通过合成分析方法,研究了中部型ENSO和平流层准两年振荡(QBO)对冬季北半球平流层臭氧的独立影响和联合调制作用。研究表明,北半球平流层臭氧在中部型厄尔尼诺年增加,而在中部型拉尼娜年减少;准两年振荡东风位相年份,北半球平流层臭氧增加,准两年振荡西风位相结果则相反。相比之下,北半球中、高纬度平流层臭氧异常对准两年振荡活动的响应明显小于其对ENSO活动的响应。进一步研究发现,准两年振荡东风位相会加强中部型厄尔尼诺事件引起的北半球平流层臭氧的增加,而减弱中部型拉尼娜事件造成的平流层臭氧的减少。在准两年振荡西风位相下,中部型厄尔尼诺事件仅导致北半球平流层臭氧含量少量升高,而中部型拉尼娜事件期间臭氧会大幅度减少。因此,准两年振荡东风位相会加强中部型厄尔尼诺事件对北半球平流层臭氧的影响,而减弱中部型拉尼娜事件对北半球平流层臭氧的影响。准两年振荡西风位相会减弱中部型厄尔尼诺而加强中部型拉尼娜事件对北半球平流层臭氧的影响。   相似文献   

15.
张峰  刘煜  李维亮 《气象科技》2012,40(3):456-465
平流层气溶胶在全球大气的辐射与化学平衡中起着重要作用,对全球气候变化有着重要的影响。数值模拟研究是研究平流层气溶胶浓度、粒径分布及其化学组成的重要手段之一。回顾了平流层气溶胶模式的发展历程,并对现今研究中较有代表性的5种模式进行了比较,着重考察了模拟结果在OCS、SO2分布情况等方面与实测数据的相符程度。结果发现5种模式均可再现平流层气溶胶和它的主要前体气体分布的大部分特征,但同时也都存在各自的局限。最后展望了平流层气溶胶模式未来的发展方向以及需要改进的问题。  相似文献   

16.
平流层气溶胶的辐射强迫及其气候响应的水平二维分析   总被引:7,自引:0,他引:7  
利用比较先进的辐射模式计算了平流层气溶胶的辐射强迫,并对之进行了参数化。结果发现平流层气溶胶的辐射强迫的水平分布不仅与其本身的水平变化有关,而且与下垫面的反照率有很大的关系。利用近期开发的二维能量平衡模式模拟了皮纳图博火山气溶胶对地面平衡温度的影响,结果表明:皮纳图博火山至喷发后1年半左右降温达最大,至喷发后第5年降温已很小。  相似文献   

17.
On 1 February 1989, -83.5°C was recorded in 27.8 hPa over Hohenpeißenberg, the lowest temperature in the 22-year series. This was measured together with a very low total ozone amount of 266 DU. This may be compared with nearly twice this amount on 27 February 1989. The situation was very unusual: following an extremely cold winter in the Arctic stratosphere, the stratospheric cold pole was located over southern Scandinavia on 1 February in a very southerly position. The analyzed temperatures of -92 °C in 30 hPa were also unusual. Even though the low ozone amounts over Hohenpeißenberg were probably dynamically caused, an additional very small ozone decrease due to heterogeneous reactions in altitudes from 23–28 km, where the temperatures lie below -80 °C, cannot be ruled out. Extinction measurements by the orbitting SAGE II instrument indeed show polar stratospheric clouds over Europe near 50° N during the period 31 January–2 February. Also, polar stratospheric clouds were previously observed over Kiruna at similarly low temperatures and signs of a corresponding small ozone decrease were noted there.  相似文献   

18.
Henry's law constants KH (mol kg–1 atm–1) for the reaction HOCl(g)=HOCl(aq) near room temperature, literature data for the associated enthalpy change, and solubilities of HOCl in aqueous H2SO4 (46 to 60 wt%) at temperatures relevant to the stratosphere (200 KT230 K) are shown to be thermodynamically consistent. Effective Henry's law constants [H*=mHOCl/pHOCl, in mol kg–1 atm–1] of HOCl in aqueous H2SO4 are given by: ln(H*)=6.4946–mH2SO4(–0.04107+54.56/T)–5862 (1/To–1/T) where T(K) is temperature and To=298.15K. The activity coefficient of HOCl in aqueous H2SO4 has a simple Setchenow-type dependence upon H2SO4 molality.  相似文献   

19.
In late December 2012 a blocking anticyclone followed by the event of minor stratospheric warming, set in the troposphere over West Siberia and, after that, over the European part of Russia. As a result of the deformation of a polar stratospheric vortex, the temperature in the lower stratosphere over Obninsk dropped below the threshold of the formation of polar stratospheric clouds. The lidar measurements of temperature, ozone values, and aerosol characteristics in the middle atmosphere were carried out at the lidar station during this atmospheric event. In three cases, polar stratospheric clouds (PSCs) referred to NAT Ia type according to the sounding results, were registered at the height of about 20 km. No considerable decrease in the ozone concentration in the area of PSC formation was revealed in these measurements.  相似文献   

20.
The potential resources on the ion-stimulated syntheses effects of aerosol particles of lower troposphere in test sites in the arctic, mountain, arid and forest areas as the function of irradiation time and gas-precursor concentration were experimentally and theoretically evaluated. The dust-free outdoor air was irradiated with an ionization current of 10− 6 A by α-rays from isotope 239Pu. The total output of radiolytic aerosols (RA) with a diameter of 3–1000 nm was found to be 0.05–0.1 molecules per 1 eV of absorbed radiation, while the physical upper limit is 0.25–0.4 molecules/eV. In an interval of exposition time from 6 to 800 s (adsorbed energy is 3 · 1012–1014 eV/cm3) the RA mass concentration at different sites was increased from 1–10 to 50–500 μg/m3. According to the liquid chromatography data the major RA material is the H2O/HNO3 solution with acid concentration  25%. The used physical model presents new aerosols as a product from small and intermediate ion association through formation of neutral clusters and describes adequately some of the peculiarities in field experiment data. Introducing SO2, NH3, and also hydrochloric, nitric and sulphuric acid vapours with concentration 0.1–1 mg/m3 in the irradiated air stimulated an increase of mass aerosol concentration by a factor of 8–30. The mean size also decreased by a factor of 3–5. These facts allowed us to expect that the chemical composition of radiolytic aerosols generated in outdoor air would noticeably differ after addition of the gas-precursors.  相似文献   

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