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1.
Seasonal and latitudinal distributions of amplitudes of quasi-biennial variations in total NO2 content (NO2 TC), total ozone content (TOC), and stratospheric temperature are obtained. NO2 TC data from ground-based spectrometric measurements within the Network for the Detection of Atmospheric Composition Change (NDACC), TOC data from satellite measurements, and stratospheric temperature data from ERA-Interim reanalysis are used for the analysis. The differences in the NO2 TC diurnal cycles are identified between the westerly and easterly phases of the quasi-biennial oscillations (QBO) of equatorial stratospheric wind. The QBO effects in the NO2 TC, TOC, and stratospheric temperature in the Northern (NH) and Southern (SH) hemispheres are most significant in the winter–spring periods, with essential differences between the NH and SH. The NO2 TC in the Antarctic is less for the westerly phase of the QBO than that for the easterly phase, and the NO2 TC quasi-biennial variations in the SH mid-latitudes are opposite of the variations in the Antarctic. In the NH, the winter values of the NO2 TC are generally less during the westerly QBO phase than during the easterly phase, whereas in spring, on the contrary, the values for the westerly QBO phase exceed those for the easterly phase. Along with NO2, the features of the quasi-biennial variations of TOC and stratospheric temperature are discussed. Possible mechanisms of the quasi-biennial variations of the analyzed parameters are considered for the different latitudinal zones.  相似文献   

2.
Quasi-biennial variations in vertical profiles of ozone, temperature, air pressure, and zonal and meridional wind velocities are analyzed from ozonesonde data obtained at the western European stations of Lindenberg, Hohenpeissenberg, and Payerne. The effect of quasi-biennial variations manifests itself variously in different variables and is nonuniform in altitude. The period of quasi-biennial variations is not constant, and the values of the mean period group mainly around 2 and 2.5 years. As in the North American region, the effects of quasi-biennial variations in different parameters of the stratosphere and troposphere over western Europe are due to a combination of the effects of the quasi-biennial oscillation (QBO) in the equatorial stratosphere, the El Niño-Southern Oscillation (ENSO), and the North Atlantic Oscillation (NAO). The observed 2.5-year variations in stratospheric ozone are related to the equatorial QBO to a larger extent in comparison with variations in other variables. It seems likely that a determining influence on variations in stratospheric wind and temperature is exerted by the ENSO. Variations in tropospheric and stratospheric parameters with a mean period of about 2 years are due to the ENSO and NAO effects.  相似文献   

3.
Statistical characteristics of major and minor sudden stratospheric warmings (SSWs) in the Northern Hemisphere (NH) for 1958–2015 are analyzed using data of NCEP-NCAR, ERA 40, and ERA-Interim reanalyses. Dependencies of the number of major SSWs with the displacement of the circumpolar stratospheric vortex and the number of minor SSWs on the phase of the quasi-biennial oscillation (QBO) of the equatorial stratospheric wind and on the level of solar activity (SA) in the 11-year solar cycle have been revealed. Major SSWs accompanied by a displacement of the polar vortex occur more often at a high level of SA and at the easterly phase of the QBO in the 50–40 hPa layer, while minor SSWs occur more often at a low SA level and at the westerly phase of the QBO. An analysis of spatiotemporal dynamics of the stratospheric polar vortex at major SSWs is performed. The most probable directions of vortex displacement caused by SSWs have been revealed. Influences of the major SSWs on the total contents of NO2 and ozone, as well as on stratosphere temperature, are analyzed.  相似文献   

4.
On the basis of satellite observations of column carbon monoxide (CO) and total ozone (TO), an analysis has been performed of the connection of the interannual variability of CO with the quasi-biennial oscillation (QBO) of the equatorial stratospheric wind and the QBO of total ozone. It is found that the CO total colomn over most of the globe in the westerly phase of the QBO is greater than that in the easterly phase. The global distribution of the CO QBO amplitudes exhibits a local maximum over Indonesia, where the peak-to-peak amplitude of the CO QBO signal averages 15% of the local annual mean CO in this region. Analysis shows that the QBOs of CO are well synchronized with the QBO of wind at 50 hPa. At the same time, a joint analysis of the characteristics of the CO QBO and TO QBO demonstrates no direct photochemical coupling between of the quasi-biennial variations of TO and CO.  相似文献   

5.
The paper focuses on the simulation of the quasi-biennial oscillations (QBOs) of zonal velocity in the equatorial stratosphere. Low-parameter models are used to examine two mechanisms for excitation of the QBO: one through the interaction of planetary waves with the mean flow at critical levels and another through gravity-wave obliteration. The possible use of each of these mechanisms for generating the QBO is shown, the ranges of parameter values where this generation is possible are determined, and the dependences of the period and amplitude of the limit cycle on the model parameters are analyzed. A relative role of waves of different scales in the formation of the period of the oscillations of zonal wind is studied with a coupled model combining both mechanisms. The conditions that are required to reproduce the QBO in general circulation models are discussed.  相似文献   

6.
Spectral characteristics of the quasi-biennial oscillations (QBO) of the zonal velocity in the equatorial stratosphere are investigated in this work on the basis of data from the NCEP/NCAR and ERA40 reanalyses and numerical experiments with the atmospheric general circulation (GCM) model developed at the Institute of Numerical Mathematics, Russian Academy of Sciences (INM RAS). The problem of synchronizing QBO and semiannual oscillations (SAO) of the zonal velocity in the mesosphere is considered. It is shown that the process of synchronization to multiples of SAO periods is identifiable in the transition region between QBO and SAO. For all heights where QBO exist, their synchronization with SAO is expressed in the calculation of the period in terms of differences between the westerly maxima. The INM RAS GCM model is shown to satisfactorily reproduce the main spectral characteristics of QBO and SAO, as well as specific features of the variability of the QBO period obtained from reanalysis data. The possibility of synchronization with SAO or the annual cycle in the upper layers is shown on the basis of an investigation of QBO models with a small number of parameters, both for the absorption mechanism of planetary waves by the mean flow and for the breaking of short gravity waves. The QBO formation from different wave types, together with SAO and the annual cycle, can be considered a unified system of oscillations in the circulation of the equatorial upper atmosphere.  相似文献   

7.
The problem of simulating quasi-biennial oscillations (QBOs) of zonal velocity in the equatorial stratosphere in atmospheric general circulation models is considered. In accordance with the results from Part I of this study on the basis of the models developed at the Institute of Numerical Mathematics of the Russian Academy of Sciences (INM RAS), the possibility of implementing (in these models) mechanisms of QBO excitation through both the interaction of planetary waves with the mean flow and breaking of short gravity waves is investigated. A new high-resolution 2° × 2.5° × 80 version of the INM RAS model is designed, a climate simulation with the two 2° × 2.5° × 39 and 2° × 2.5° × 80 versions of the INM RAS model is briefly described, results of spectral analysis of equatorial wave activity are presented, and the QBO formation processes in these models are considered in detail. For the new 2° × 2.5° × 80 model, realistic QBOs of zonal wind are obtained as the result of the action of both mechanisms.  相似文献   

8.
Characteristics of the Arctic Oscillation and El Niño-Southern Oscillation effects manifested on interannual scales in the equatorial stratosphere are determined. Wavelet analysis of local phase shifts, coherence, and correlation is used to obtain correlation portraits of the largest factors of climate variability against the background of coherent variations in the equatorial stratospheric wind speed at the 50- and 15-hPa pressure levels. It is shown that the Arctic Oscillation and El Niño-Southern Oscillation signals may reach the tropical stratosphere. The signals are easily identified in a wide range of scales, including quasi-biennial, 3-to 5-year, and 10-to 11-year periods. The results obtained reflect a coherent pattern of the manifestation of these signals at the selected stratospheric levels. It is found that the El Niño-Southern Oscillation effect at periods close to 10–11 years reaches the stratospheric level rather rapidly, in the same or next month, while the effects of the Arctic Oscillation index are delayed by nine months. The estimates obtained show that a phase shift of almost 180° in the Arctic Oscillation index relative to the equatorial stratospheric wind occurred in almost all of the range of interannual periods in 1978 and 1992. For the El Niño-Southern Oscillation, an increase in local correlations on a scale of 3-to 5-year variations was observed in 1980–1990, a 180° phase shift occurred in 1992, and the correlation with stratospheric wind increased in 1992–2004. The estimates obtained are indicative of a change in the atmospheric circulation pattern that took place in the Northern Hemisphere in 1978–1991.  相似文献   

9.
On the basis of ground-based measurements of total ozone content (TOC) over Russia and a number of neighboring states during 1973–2002, the amplitudes and phases of TOC variations caused by the quasi-biennial oscillation (QBO) of wind in the equatorial stratosphere are estimated for different regions and for the whole area. The seasonal dependence of the QBO effect in the TOC is analyzed. It is shown that the magnitude and even the sign of the effect depend on the relation between the equatorial QBO phase and the season. The regional empirical models of seasonally dependent QBO effects are constructed. It is found that the seasonal dependence of regional effects accounts for 4% (in the north of the area) to 20% (in the south) of the interannual variability of the TOC. The relation between the QBO effect and the 11-year cycle of solar activity is analyzed. Significant differences are revealed in the effects under the conditions of maximum and minimum solar activity. The QBO effects obtained from observations at Russian stations, satellite measurements with a TOMS instrument, and spectrometric observations of the TOC at western European stations are compared, and their satisfactory agreement is shown. An analysis of the results suggests that the QBO effects in the TOC over Russia are caused by several interacting factors and apparently reflect their regional properties.  相似文献   

10.
Variability of sea level in the Sea of Japan is studied using multivariate analysis of weekly altimetry fields spanning from October 1992 through October 2009. Interacting (non-orthogonal) modes of variability are revealed on seasonal time scale, representing synchronous oscillations in the entire Sea and meridional sea level gradient, respectively. The highest sea level and sharpest gradient occur in October and the strongest opposite phase occurs in March. Intra-seasonal and quasi-biennial synchronous oscillations also occur. The fluctuations of the level gradients are not statistically significant on these time scales. The 180-degree-out-of-phase oscillations occur in the western and eastern parts of the Sea on semiannual, annual, quasi-biennial, and longer interannual time scales, manifesting substantial changes in the regional circulation patterns. No secular trends related to the revealed modes were detected.  相似文献   

11.
利用50 a的SODA资料对1月(冬季)和7月(夏季)印度洋越赤道经向翻转环流的年际变化进行研究。通过对2类典型年份的合成分析指出:1月份正异常年对应的经向翻转环流偏强,向北的经向热输送增加;7月份正异常年对应的经向翻转环流则偏弱,向南的经向热输送减少;1月份和7月份的负异常年皆与其正异常年相反;越赤道经向翻转环流有明显的年际变化,平均周期在4 a左右;经向翻转环流的年际变化和海面风场的变化密切相关。提出了反映1月和7月此环流年际变化的几个指数。  相似文献   

12.
Izvestiya, Atmospheric and Oceanic Physics - The sensitivity of the residual meridional circulation (RMC) in the middle and upper atmosphere to the phase change of the quasi-biennial oscillation...  相似文献   

13.
An analysis of the high-latitude ozone balloon sounding data derived from Canadian stations shows that, in the maximum of the 11-year cycle of solar activity (SA), the ozone content in the lower stratosphere is higher than in the SA minimum and, in the SA maximum, the lower stratosphere is warmer and the troposphere is colder than in the SA minimum. The ozone and temperature responses to the equatorial quasi-biennial oscillation (QBO) in the opposite phases of the 11-year cycle of SA show substantial differences: in the SA maximum, the QBO effects in the ozone and temperature cover a wider range of heights, the maxima of the effects manifest themselves at 5–10 km higher, and their amplitudes exceed the amplitudes of the effects in the SA minimum. The results indicate that the QBO is one of the “conductors” of the influence of the 11-year SA cycle in the Canadian sector of the Arctic.  相似文献   

14.
Parameterizations of normal atmospheric modes (NAMs) and orographic gravity waves (OGWs) are implemented into the mechanistic general circulation model of the middle and upper atmosphere (MUA). Numerical experiments of sudden stratospheric warming (SSW) events are performed for climatological conditions typical for January and February using meteorological reanalysis data from the UK MET Office in the MUA model averaged over the years 1992–2011 with the easterly phase of quasi-biennial oscillation (QBO). The simulation shows that an increase in the OGW amplitudes occurs at altitudes higher than 30 km in the Northern Hemisphere after SSW. The OGW amplitudes have maximums at altitudes of about 50 km over the North American and European mountain systems before and during SSW, as well as over the Himalayas after SSW. At high latitudes of the Northern Hemisphere, significant (up to 50–70%) variations in the amplitudes of stationary planetary waves (SPWs) are observed during and after the SSW. Westward travelling NAMs have local amplitude maximums not only in the Northern Hemisphere, but also in the Southern Hemisphere, where there are waveguides for the propagation of these modes. Calculated variations of SPW and NAM amplitudes correspond to changes in the mean temperature and wind fields, as well as the Eliassen-Palm flux and atmospheric refractive index for the planetary waves, during SSW. Including OGW thermal and dynamical effects leads to an increase in amplitude (by 30–70%) of almost all SPWs before and during SSW and to a decrease (up to 20–100%) after the SSW at middle and high latitudes of the Northern Hemisphere.  相似文献   

15.
This study investigated the eastern Pacific Intertropical Convergence Zone (ITCZ) as an atmospheric forcing to the ocean by using various observed and reanalysis data sets over 29 years. Climatologically, a zonal band of positive wind stress curl (WSC) with a 10° meridional width was exhibited along the ITCZ. A southward shift of the positive WSC band during the El Niño phase induced a negative (positive) WSC anomaly along the northern (southern) portion of the ITCZ, and vice versa during the La Niña phase. This meridional dipole accounted for more than 25 % of interannual variances of the WSC anomalies (WSCAs), based on analysis of the period 1993–2008. The negative (positive) WSCA in the northern portion of the ITCZ during the El Niño (La Niña) phase was collocated with a positive (negative) sea surface height anomaly (SSHA) that propagated westward as a Rossby wave all the way to the western North Pacific. This finding indicates that this off-equatorial Rossby wave is induced by the WSCA around the ITCZ. Our analysis of a 1.5-layer reduced gravity model revealed that the Rossby waves are mostly explained by wind stress forcing, rather than by reflection of an equatorial Kelvin wave on the eastern coastal boundary. The off-equatorial Rossby wave had the same SSHA polarity as the equatorial Kelvin wave, and generation of a phase-preserving Rossby wave without the Kelvin wave reflection was explained by meridional movement of the ITCZ. Thus, the ITCZ acts as an atmospheric bridge that connects the equatorial and off-equatorial oceanic waves.  相似文献   

16.
本文对海-气边界层波致风机制的相关理论进行了阐述,并利用ERA-40再分析资料给出了太平洋谱峰速度、波龄、波陡等描述涌浪和波致风机制物理量的年际和季节空间分布特征。分析表明:东太平洋赤道地区等海域涌浪速度最大且涌浪由南向北传播明显;太平洋波边界层高度基本呈现出东高西低的分布形势;波致风机制主要发生在赤道热带海域,北半球夏季波致风机制偏强,冬季偏弱,南半球反之;北半球北部海域夏季更易发生波致风机制,赤道附近海域相反;南海为风浪与涌浪组成的混合浪,对其波候等相关研究有必要分开进行讨论。  相似文献   

17.
印度洋上层海气相互作用对印度洋和太平洋气候系统有重要影响。目前针对印度洋气候态环流特征已有较为全面的研究,但针对印度洋环流的年际变化及其季节性差异的特征分析和具体作用机制,仍缺乏深入的研究。本文利用1979—2007年Simple Ocean Data Assimilation(SODA)再分析资料研究了赤道印度洋表层辐合辐散的年际变异及其季节依赖性。结果表明,以赤道为中心,印度洋上层异常海流,在经向上形成显著的辐合(辐散)现象,究其原因主要是赤道纬向风异常形成的Ekman流所导致。进一步分析表明,热带印度洋异常纬向风的成因与太平洋-印度洋的热力强迫过程作用有关,并且不同的热力强迫过程呈现出显著的季节差异性。此热力强迫过程,具体可分为3种类型:第一类是太平洋纬向海表热力差异的遥强迫作用,主要发生在冬末春初,热带太平洋的纬向热力差异通过调节Walker环流,在印度洋激发出一个异常的次级环流,对应的大气低层形成纬向风异常;第二类是东-西印度洋海表热力差异的局地强迫作用导致的局地环流,使赤道印度洋上空形成纬向风异常,此过程在春末夏初较为显著;第三类是太平洋-印度洋热力差协同作用的结果,使赤道印度洋盛行异常的纬向风,此过程在秋季起主导作用。  相似文献   

18.
Time-longitude diagrams of monthly anomalies of TOPEX/Poseidon sea surface height (SSH), Levitus steric height, COADS wind stress curl, as well as meridional surface wind averaged over the northern South China Sea (SCS) from 18° to 22°N, exhibit a coherent westward phase propagation, with a westward propagation speed of about 5 cm s−1. The consistency between oceanic and atmospheric variables indicates that there is a forced Rossby wave in the northern SCS. The horizontal patterns of monthly SSH anomalies from observations and model sensitivity experiments show that the forced Rossby wave, originating to the northwest off Luzon Island, actually propagates west-northwestward towards the Guangdong coast because of zonal migration of the meridional surface wind. The winter Luzon Cold Eddy (LCE), which has been found from field observations, can be identified as a forced Rossby wave with a negative SSH anomaly in winter. It corresponds to strong upwelling and a negative temperature anomaly. Sensitivity experiments show that the wind forcing controls the generation of the LCE, while the Kuroshio is of minor importance.  相似文献   

19.
The distributions of kinetic energy (KE) and available potential energy (APE) in the lower and middle atmosphere of the Northern and Southern hemispheres over the period 1992–2003 are investigated. Annual mean values of the amplitude and phase of annual and semiannual oscillations in the zonal and eddy forms of KE and APE are calculated in the height range 0–55 km (1000–0.316 hPa) for the 21st layer. A clearly pronounced annual cycle of the zonal and eddy components of KE and APE with maxima in the winter season are observed in the troposphere of both hemispheres. In the lower stratosphere, the annual-cycle maximum is shifted toward the summer season because of the meridional gradient of the zonal mean temperature. In the stratosphere of both hemispheres, along with annual oscillations, semiannual oscillations are present in all forms of energy. The intensity of these oscillations for the zonal KE and APE at the upper-stratosphere heights is comparable to the intensity of annual oscillations. A local structure of the energy regime of the upper mesosphere-lower thermosphere is investigated against the background of the global energy regime from the data of meteor sounding in Kazan. It is shown that, for both the global and regional regimes, specific features of the phase profiles of energy characteristics can be explained by the presence of barriers during the propagation of wave disturbances along the vertical.  相似文献   

20.
本文应用Hadley Center提供的全球最新海表温度资料,分析探讨了赤道太平洋和印度洋-南海(简称印-南)暖池区域海表面温度异常(SSTA)与西太平洋副热带高压(简称副高)变化的关系,结果表明,赤道东太平洋SSTA和印-南暖池区域SSTA对副高的影响存在明显的时空分布差异,它们二者对副高变化存在协同作用的影响。前者对副高的影响始于超前一年的春季,持续到当年的春季。后者则始于前冬,持续到当年的夏季。赤道东太平洋SSTA对副高的影响主要通过对经向环流影响所致,印-南暖池区域SSTA对副高影响的主要途径是通过经向环流和水汽输送,前者主要体现在对对流层中低层经向Hadley环流的影响,而后者主要体现在对对流层低层经向季风环流及其伴随的水汽输送的影响,它们二者对副高的影响机理存在不同。作者提出了赤道东太平洋和印-南暖池区域SSTA对副高存在协同影响作用,并通过最优子集回归分析,建立了副高异常变化的预测模型,对2015年5-8月副高强度进行了预测,其结果是5-8月的副高强度较常年偏强,扣除超强台风的影响,预测结果正确,由此可以认为,本文建立的预测模型是可靠的。这一工作的特点是强调了赤道东太平洋和印-南暖池的协同作用对副高持续性的影响,为副高异常变化及其降水的预测提供更为可靠的依据。  相似文献   

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