首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 753 毫秒
1.
热带平流层臭氧准两年周期振荡的特征及数值模拟   总被引:19,自引:1,他引:19  
利用HALOE的观测资料、对热带地区平流层臭氧垂直分布的年际变化及其准两年周期振荡(QBO)进行研究,并同赤道上空平均的纬向风场的准两年周期振荡进行了模拟研究。资料分析结果表明,平流层臭氧浓度高值区的位置在南北方向上和垂直方向上的有明显的准两年周期,臭氧浓度高值中心的南北移动和上下移动又引起局地臭氧总量的周期性变化和准两年周期振荡南北半球不对称。而臭氧浓度中心位置的准两年周期变化与赤道上空平均纬向风的准两年周期振荡密切相关。资料分析还表明,赤道上空平流层中臭氧浓度QBO的位相随高度变化多次。模拟试验表明,纬向风QBO引起垂直经圈环流的变化,在平流层有三对余差环流圈。它们对O3在不同纬度和高度的输送是引起O3准两年周期振荡的重要动力原因。其中,余差环流在平流层中层(25-35km)的环流圈起着重要的作用。  相似文献   

2.
热带准两年振荡影响北半球冬季大气环流的诊断分析   总被引:11,自引:3,他引:8  
陈文  杨蕾  黄荣辉  邱启鸿 《大气科学》2004,28(2):161-173
利用NCEP/NCAR再分析资料,首先讨论了热带纬向风准两年振荡(QBO)的东、西风位相的划分标准.结果发现,赤道50 hPa的风与西风深厚度关系最密切,即赤道50 hPa的纬向平均风为西(东)风时往往代表平流层下层为一层深厚的西(东)风.在此基础上诊断分析了1958/1959~1997/1998年共40个冬季中热带纬向风QBO对北半球中高纬度地区纬向平均环流和准定常行星波传播的影响.诊断分析表明,热带QBO对北半球冬季大气环流的影响主要表现在平流层和对流层上层.热带QBO的东风位相年与西风位相年相比,中高纬地区的绕极西风环流明显减弱,中低纬地区则出现相反变化,从而在平流层的纬向平均环流分布上呈现偶极子形式.纬向平均流的这种年际变化可以很好地用中高纬度准定常行星波传播的异常加以解释,QBO的东风位相年和西风位相年相比,中高纬准定常行星波向极地的传播更强,从而在高纬度平流层产生异常的E-P通量辐合,波-流相互作用的结果使得西风减弱.但是热带纬向风QBO的影响在1958/1959~1997/1998年的前后20年有所差异.后20年相对于前20年而言,东西风位相的差异有所减小,Hol-ton-Tan振荡明显减弱;就行星波传播而言,东风位相年下,前20年行星波向上传播较弱,而后20年则以大约70°N为分界点,以南向上传播较强,以北向上传播较弱.这种差异可能跟中高纬度纬向西风的自身变化有关.  相似文献   

3.
青藏高原臭氧的ENSO   总被引:9,自引:4,他引:5  
通过对臭氧卫星观测资料及大气环流资料的分析,研究了青藏高原上空臭氧年际变化中的ENSO信号,并与同纬度无山区及赤道地区进行比较.研究指出:在ElNino年(南方涛动指数为负),青藏高原臭氧总量偏大,在LaNina年(南方涛动指数为正),青藏高原臭氧总量偏小.同时讨论了与ENSO事件有关的大气环流物质输送.  相似文献   

4.
平流程准两年振荡(QBO)是赤道平流层(~100-1 hPa)变率的主要模态,可对中高纬地区的环流产生重要影响,但目前利用通用大气环流模式(GCM)对其进行准确模拟仍然是一个挑战.本文利用IAP大气环流模式(IAP-AGCM)的中高层大气模式版本(IAP-AGCML69)对QBO进行模拟,并对其动量收支情况进行分析.研究发现,QBO主要是由对流活动引起的重力波强迫(参数化)引起的,但该动量强迫被平流层赤道上升流所引起的平流过程显著削弱.模式可分辨尺度的波动强迫对赤道上空的QBO的总纬向风倾向有正贡献,在上平流层,其量值大小与参数化的重力波强迫相当.以上结果提供了QBO形成机制以及模式模拟差异可能原因的认识.  相似文献   

5.
陈文  黄荣辉 《大气科学》1996,20(5):513-523
本文构造了一个34层球坐标原始方程波-流相互耦合谱模式,利用此模式从拉格朗日平均环流的观点研究了在常定流下行星波对臭氧的输运作用。研究结果表明,行星波对臭氧的输运有明显的季节变化,在北半球冬季,由于行星波上传到平流层而大大增强了中高纬地区向极地向下的O3输运;并且还表明,热带纬向风的QBO不仅通过影响东、西风切变而引起热带O3分布的年际变化,而且通过影响行星波的传播引起了行星波对O3输运的年际变化,这表现为当热带纬向风处于东风位相时,中高纬地区行星波对O3的输运比西风位相时强  相似文献   

6.
青藏高原臭氧的ENSO   总被引:3,自引:0,他引:3  
通过对臭氧卫星观测资料及大气环流资料的分析,研究了青藏高原上空臭氧年际变化中的 ENSO信号,并与同纬度无山区及赤道地区进行比较。研究指出:在 E1 Nino年(SOI指数为负)青藏高原臭氧总量增加,在 La Nina年(SOI指数为正)青藏高原臭氧总量减小。本文同时讨论了与ENSO事件有关的大气环流物质输送。  相似文献   

7.
平流层准两年振荡(QBO)是赤道平流层(~100-1 hPa)变率的主要模态,可对中高纬地区的环流产生重要影响,但目前利用通用大气环流模式(GCM)对其进行准确模拟仍然是一个挑战.本文利用IAP大气环流模式(IAP-AGCM)的中高层大气模式版本(IAP-AGCML69)对QBO进行模拟,并对其动量收支情况进行分析.研究发现,QBO主要是由对流活动引起的重力波强迫(参数化)引起的,但该动量强迫被平流层赤道上升流所引起的平流过程显著削弱.模式可分辨尺度的波动强迫对赤道上空的QBO的总纬向风倾向有正贡献,在上平流层,其量值大小与参数化的重力波强迫相当.以上结果提供了对QBO形成机制以及模式模拟差异可能原因的认识.  相似文献   

8.
陈文  黄荣辉 《大气科学进展》2002,19(6):1113-1126
利用变换欧拉平均方程讨论了行星波动力学,观测和模拟结果都表明,在北半球冬季准定常行星波的经向传播存在两支波导。一支为高纬度波导,另一支则为低纬度波导。这些结果与理论分析相当一致。通过对EP通量进一步的研究表明,平流层爆发性增温是沿高纬度波导传播的异常行星波与平均气流相互作用的结果。而热带风场的准两年周期振荡(QBO)是低纬度平流层下层大气纬向平均流的一个重要年际变化,它可以影响行星波沿低纬度波导的传播;此外,由一个行星波-平均流耦合模式模拟的结果表明,这个热带风场的变化还可以通过波流相互作用调制行星波沿高纬度波导的传播。行星波对臭氧的输运作用在中也进行了分析,行星波强迫出的剩余平均环流表明,耗散的行星波有强的输运作用;向北的涡动热量输送可以强迫出一个正的输运环流,其在低纬度上升并在高纬度下沉。同时研究还表明,热带风场的QBO对行星波传播的调制对输运环流也有重要影响,模式结果表明,在QBO的东风位相期间行星波引起的输运作用明显增强,其结果可用于解释平流层高纬度臭氧的年际变化。  相似文献   

9.
郑彬  陈月娟  张弘 《大气科学》2003,27(6):1007-1017
利用NCAR的包含化学、辐射、动力相互作用的二维模式就纬向风的准两年周期振荡(简称QBO)对平流层微量元素分布的影响进行数值模拟试验.模拟中,输入纬向风QBO的值,计算出NOx、臭氧浓度和各种气象要素的垂直经向分布,并与不考虑QBO强迫的数值模拟结果进行对比.在第Ⅰ部分HALOE资料分析的基础上,进一步讨论了在纬向风QBO的影响下NOx浓度垂直分布的变化及其准两年周期振荡,并研究了NOx的QBO与臭氧QBO的关系.结果表明:模拟六年平均的NOx混合比分布与观测结果基本一致,并且在纬向风场QBO强迫下,NOx混合比扰动有明显的准两年周期振荡;与臭氧的QBO比较,发现在28 km以下,NOx的QBO与臭氧QBO同位相,而在28 km以上,它们则是反位相,与HALOE资料的观测结果基本吻合.文中对模拟得到的由于风场QBO引起的余差环流输送作用做了进一步的分析,并讨论了在不同高度的气层中余差环流的输送作用与NOx破坏作用在臭氧QBO形成中的相对重要性.  相似文献   

10.
王春晓  田文寿 《大气科学》2017,41(2):275-288
利用2005~2014年10年的卫星微波临边探测仪(MLS)资料分析了热带平流层一氧化碳(CO)体积混合比的年际变率,发现热带平流层CO浓度的准两年振荡(QBO)在30 hPa高度附近存在明显的位相变化特征。大气化学气候模式模拟结果表明,热带平流层CO的准两年振荡信号是化学和动力过程共同作用的结果,而动力作用主要是QBO引起的次级经向环流引起的物质传输。化学和动力过程共同作用导致热带平流层CO浓度的垂直梯度在30 hPa高度处发生反转,进而产生一氧化碳QBO信号的位相变化。此外,化学气候模式模拟结果还表明,与CO有关的化学过程不但可以减弱一氧化碳QBO信号的振幅,还可以在热带30~10 hPa高度范围内造成一氧化碳QBO和纬向风QBO信号之间约3个月的时间差。  相似文献   

11.
1. IntroductionOzone is one of the trace gases in the atmosphere distributed in 10--50 km altitude withthe maximum in 20--28 km. Ozone is significant in the following three aspects impacting theclimate and environment: 1) Ozone absorbs harmful solar ultra--violet radiation for protecting the ecological system on the Earth; 2) ozone heats the stratosphere and forces the circulation systems in this layer; 3) ozone variation in the stratosphere can change the incomingradiation at the surface leve…  相似文献   

12.
A Tibetan ozone low was found in the 1990s after the Antarctic ozone hole.Whether this ozone low has been recovering from the beginning of the 2000s following the global ozone recovery is an intriguing topic.With the most recent merged TOMS/SBUV(Total Ozone Mapping Spectrometer/Solar Backscatter Ultra Violet) ozone data,the Tibetan ozone low and its long-term variation during 1979-2010 are analyzed using a statistical regression model that includes the seasonal cycle,solar cycle,quasi-biennial oscillation(QBO),ENSO signal,and trends.The results show that the Tibetan ozone low maintains and may become more severe on average during 1979-2010,compared with its mean state in the periods before 2000,possibly caused by the stronger downward trend of total ozone concentration over the Tibet.Compared with the ozone variation over the non-Tibetan region along the same latitudes,the Tibetan ozone has a larger downward trend during 1979-2010,with a maximum value of-0.40±0.10 DU yr 1 in January,which suggests the strengthening of the Tibetan ozone low in contrast to the recovery of global ozone.Regression analyses show that the QBO signal plays an important role in determining the total ozone variation over the Tibet.In addition,the long-term ozone variation over the Tibetan region is largely affected by the thermal-dynamical proxies such as the lower stratospheric temperature,with its contribution reaching around 10% of the total ozone change,which is greatly different from that over the non-Tibetan region.  相似文献   

13.
Summary Analysis of ozonesonde data shows that in the lower troposphere above Hong Kong, there is a relative maximum with respect to height in all seasons except winter. In the upper troposphere, there is with respect to height a relative minimum in the seasonally averaged ozone mixing ratio in winter. Ozone mixing ratios in the upper troposphere in winter and spring can be significantly enhanced by stratospheric intrusions associated with the passage of cold fronts and upper cut-off lows.For Hong Kong, the seasonally averaged total ozone has the highest value in spring, and the lowest in winter. The seasonally averaged total tropospheric ozone also has the highest value in spring, but the lowest in summer. In a relative sense, total tropospheric ozone contributes most to the total ozone in spring and the least in summer.The phase of the total ozone anomaly above Hong Kong is influenced by the Quasi-Biennial Oscillation (QBO), with the positive anomaly associated with the easterly phase of QBO, and the negative anomaly the westerly phase.  相似文献   

14.
大尺度山地上空的臭氧低值及地面加热   总被引:11,自引:0,他引:11  
首次利用Nimbus-7卫星上搭载的臭氧观测光谱仪(TOMS)资料,分析研究了大尺度山地(青藏高原、洛基山脉和安第斯山脉)上空臭氧总量的分布和季节变化规律,指出了大尺度山地对大气臭氧的减少作用。从全球大气臭氧总量分布和纬向偏差分布可以看出:在上述3个大尺度山地上空均存在着明显的臭氧低值扰动,该扰动区夏季强于冬季。在这3个区域中,青藏高原上空的臭氧低值扰动为最强。分析同时指出:上述大尺度山地上空臭氧季节变化的极小值在秋季,极大值在春季。但上述地区臭氧总量与同纬度其它地区臭氧总量的偏差在春季或初夏达到极小值。为分析这种大尺度山地对臭氧减少作用的原因,本文分析了青藏高原地面热源与臭氧总量的关系,指出:大尺度山地表面对大气的加热与该地区臭氧减少之间存在着良好的反相关;在地面对大气的感热加热、潜热加热和有效长波辐射加热中,以感热加热与臭氧减少的关系为最好。  相似文献   

15.
In most climate simulations used by the Intergovernmental Panel on Climate Change 2007 fourth assessment report, stratospheric processes are only poorly represented. For example, climatological or simple specifications of time-varying ozone concentrations are imposed and the quasi-biennial oscillation (QBO) of equatorial stratospheric zonal wind is absent. Here we investigate the impact of an improved stratospheric representation using two sets of perturbed simulations with the Hadley Centre coupled ocean atmosphere model HadGEM1 with natural and anthropogenic forcings for the 1979–2003 period. In the first set of simulations, the usual zonal mean ozone climatology with superimposed trends is replaced with a time series of observed zonal mean ozone distributions that includes interannual variability associated with the solar cycle, QBO and volcanic eruptions. In addition to this, the second set of perturbed simulations includes a scheme in which the stratospheric zonal wind in the tropics is relaxed to appropriate zonal mean values obtained from the ERA-40 re-analysis, thus forcing a QBO. Both of these changes are applied strictly to the stratosphere only. The improved ozone field results in an improved simulation of the stepwise temperature transitions observed in the lower stratosphere in the aftermath of the two major recent volcanic eruptions. The contribution of the solar cycle signal in the ozone field to this improved representation of the stepwise cooling is discussed. The improved ozone field and also the QBO result in an improved simulation of observed trends, both globally and at tropical latitudes. The Eulerian upwelling in the lower stratosphere in the equatorial region is enhanced by the improved ozone field and is affected by the QBO relaxation, yet neither induces a significant change in the upwelling trend.  相似文献   

16.
NUMERICAL INVESTIGATION OF QBO IN OZONE   总被引:1,自引:0,他引:1  
In this paper, a two-dimensional primitive equation model, coupling dynamical, radiative andphotochemical processes, is used to simulate the quasi-biennial oscillation (QBO) in ozone. TheQBO in total ozone has been successfully simulated when the forcing of equatorial stratosphericQBO in zonal wind is imposed. The simulated characters of QBO in ozone are in close agreementwith those observed. We further analyzed the mechanism of formation and maintenance of QBO inozone. In the different phases of QBO in equatorial stratospheric wind field, the global circulationhas so great difference that it makes the effects of advection transfer and eddy transfer present aquasi-biennial periodical variation. Chemical effect and dynamical effect are basically out-of-phase.They together form and maintain the QBO in ozone. Total variation rate is a tiny difference of thetwo large amounts. At the lower level of middle-high latitudes, however, it has a phase differenceof about 1-2 months between dynamical and negative chemical effects, where the dynamical effectis comparatively greater. QBO in ozone has no clear counter effects on atmospheric circulation. The experiment resultsshow that the effects of QBO in ozone on temperature field and wind field are very small.  相似文献   

17.
The analysis of external factors, which are most significant for the formation of the monthly mean total ozone (TO) field and ozone transport over the Russian Federation, based on observation data obtained from about 30 ground-based stations of the ozonometric network averaged over a year, December through March and June through August, over five climatic regions, is considered. Performed spectrum and discriminant analysis allowed obtaining quantitative estimates of the impact of the Arctic Oscillation, deviation of the winter temperature of the lower polar stratosphere, quasi-biennial oscillations (QBO), 11-year solar cycle, El Niño-Southern Oscillation (ENSO) on the TO and to assess the regional differences in the effects of these factors. In December–March, in the years with a negative Arctic Oscillation phase, warm stratosphere, and the easterly QBO phase (QBO-E), the ozone content increases significantly relative to the opposite phases of oscillations on average by 35, 28, and 26 Dobson units (DU), respectively. The spectra, similar to the discriminant function, demonstrate strong influence of the 11-year solar cycle and QBO on the TO even in the summer months, while the QBO is more pronounced in the eastern part of the Russian Federation. The ENSO effect was not singled out against the general “noisy” background of the cold six-month period, when many atmospheric processes become active: however, during the summer months, in warm periods of the ENSO, the TO, at the 97% significance level, increases over most of the Russian area. The rest of the obtained results are significant at the 95–99.9% level.  相似文献   

18.
1. Introduction The quasi-biennial oscillation (QBO) of the mean zonal wind in the equatorial stratosphere was discov- ered by Reed et al. (1961) and Veryard and Ebdon (1961). Later, Funk and Garnham (1962) and Ra- manathan (1963) were the first to descri…  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号