A Possible Transfer Mechanism for the 11-Year Solar Cycle to the Lower Stratosphere

Observational evidence of the 11-year solar cycle (SC) modulation of stratosphere temperatures and winds from the ERA-40 dataset is reviewed, with emphasis on the Northern winter hemisphere. A frequency modulation of sudden warming events is noted, with warmings occurring earlier in solar minimum periods than in solar maximum periods. The observed interaction between the influence of the SC and the quasi biennial oscillation (QBO) on the frequency of sudden warmings is noted as a possible clue for understanding their mechanism of influence. A possible transfer route for the 11-year solar cycle from the equatorial stratopause region to the lowest part of the stratosphere is proposed, via an influence on sudden warming events and the associated induced meridional circulation. SC and QBO composites of zonal wind anomalies show anomalous wind distributions in the subtropical upper stratosphere in early winter. Mechanistic model experiments are reviewed that demonstrate a sensitivity of sudden warmings to small wind anomalies in this region. Various diagnostics from these experiments are shown, including EP fluxes and their divergence and also the synoptic evolution of the polar vortex, in order to understand the mechanism of the influence. Some recent GCM experiments to investigate the SC/QBO interaction are also described. They simulate reasonably well the observed SC/QBO interaction of sudden warming events and appear to support the hypothesis that tropical/subtropical upper stratospheric wind anomalies are an important influence on the timing of sudden warmings.     

对流层顶变化对上对流层/下平流层臭氧分布的影响

上对流层和下平流层(UT／LS)，位于8-25km高度之间，是大气中一个很特殊的区域．大部分的臭氧分布在下平流层，在下平流层臭氧的含量发生一个很小的变化，就会对气候和地面的紫外辐射产生很大的影响．而作为气象参数的对流层顶，是充分混合、缺乏臭氧的上对流层和层结稳定、臭氧丰富的下平流层之间的边界或过渡层，其变化对臭氧总量和分布有直接和明显的影响．本文使用二维模式模拟研究对流层顶变化对臭氧在UT／LS分布的影响．模拟结果表明对流层顶的季节变化对UT/LS的臭氧分布有明显的影响，臭氧的局地变化可以超过10％在冬季北半球中纬度对流层顶高度升高1km时，模式结果表明对臭氧分布的影响比较显著，局地变化可超过6％，但是对臭氧总量的影响较小，变化不超过5DU，小于观测资料统计分析的结果。     

Some additional results in the regular balloon monitoring of cosmic rays in the Earth’s atmosphere

The different types of the data recorded in the experiment of the regular balloon monitoring of cosmic rays (carried out since 1957 by Lebedev Physical Institute, Moscow, Russia, in several locations) are described. So called detailed information (the form of each pulse detected by the ground-based receiver) recorded during the last 12 years is discussed in more details. The use of these data both for getting and correcting the standard results of the experiment and for obtaining some additional information on the cosmic rays in the Earth’s atmosphere is considered.     

Height-latitude structure of stationary planetary waves in the stratosphere and lower mesosphere

Daily UK Met Office stratospheric assimilated data for the Northern and Southern Hemispheres, accumulated for the period from 2004 to 2012 and pressure range of 1000–0.1 hPa, are used in this paper. The paper presents and thoroughly discusses spatial–temporal distributions of stationary planetary wave (SPW) amplitudes and phases, calculated on the basis of geopotential height, temperature, zonal and meridional wind data for zonal wave numbers 1 and 2 (SPW1 and SPW2). The climatological planetary wave amplitudes and phases are calculated by extracting waves from three types of data: daily, monthly mean and climatological monthly mean. It has been established that magnitude of amplitudes and height-latitude distribution of amplitudes of SPW1 and SPW2 depend on data processing method for all parameters. It has also been established that height-latitude distribution amplitudes and phases significantly differ for geopotential height, temperature, zonal and meridional wind and depend on wave number and hemisphere. However, height-latitude distributions of phases are little different from each other for the used methods of data processing.     

Influence of the Solar Cycle on the General Circulation of the Stratosphere and Upper Troposphere

The record of dynamical structure reveals a systematic variation that operates coherently with the 11-yr variation of UV irradiance. Involving periods shorter than 5 years, the systematic variation reflects the influence of the QBO on the polar-night vortex. It has the same basic structure as interannual changes associated with the residual mean circulation of the stratosphere. A signature of the solar cycle also appears in the direct correlation to solar flux, as recovered through regression of the entire monthly record. That signature, however, is sharply enhanced around solstice, when the residual circulation is active, and during extremal phases of the QBO. In the tropics, the solar signature follows, throughout the year, from a decadal modulation in the frequency of the QBO. The modulation is manifested to either side of the QBO’s mean frequency, in two spectral peaks where the QBO dwells: one at (24 months)⁻¹, reflecting a Biennial Oscillation (BO), and another at (36 months)^-1. Intrinsic to the QBO, those peaks are separated from its mean frequency by ∼11 years⁻¹.Through the QBO’s residual circulation, the decadal modulation introduces anomalies in the subtropics, with symmetry about the equator. Accompanying anomalous temperature in the subtropics is a stronger signature over the winter pole. Discovered by Labitzke and van Loon 1988, that solar signature reflects anomalous downwelling of the Brewer-Dobson circulation. It is shown to follow through the BO, which is intrinsic to the QBO and its modulation of the polar-night vortex.     

中国中部低层大气行星波无线电探空仪的观测研究

通过分析武汉、宜昌和恩施气象局无线电探空仪2001-2003年的观测数据,研究了中国中部地区对流层和低平流层中行星波的特性.通过Lomb-Scargle(L-S)的周期图方法发现了周期为准16天和周期为准10天的谱分量占据着主导地位.观察发现,较大振幅的行星波振荡主要集中在5-15 km之间.准16天行星波沿纬圈向西传播,对应的纬圈波数大约为2,水平波长约为17 324.8 km,传播相速度约为-12.5 m·s-1(东向为正),通过计算准16天行星波在10 km以下相位随高度的改变可以得到其垂直波长大约为25-30 km,而在对波层顶附近其相位几乎没有发生改变,呈现出静态波特性.准10天行星波沿纬圈向东传播,对应的纬圈波数大约为4,水平波长约为8627.3 km,传播相速度约为10.0 m·s-1,垂直波长约为22-40 km.      

高空长航时太阳能无人机总体设计要点分析

高空长航时（HALE）太阳能无人机（UAV）的基本工作原理与常规动力飞机相比有显著的区别,体现在飞机总体设计方法上有其独到之处,方案设计中还需要对一些关键技术细节进行认真权衡。阐述了高空长航时太阳能无人机总体设计中遵循的重量不变和能量平衡原则的机理,同时从太阳能无人机巡航平飞功率需求、布局形式选取、飞行剖面优化和临近空间使用环境影响等方面出发,研究了太阳能无人机总体设计中的若干注意事项,主要结论可用于高空长航时太阳能无人机总体设计和方案优化。     

Quasi-biennial oscillation (QBO) of tropical total ozone under alternative QBO scenarios of equatorial stratospheric wind

Equatorial total column ozone variations with quasi-biennial periodicity are described by paying attention to their coupling with the quasi-biennial oscillation (QBO) of zonal wind in equatorial stratosphere. Analysis is made for the 35-year time interval from 1978 to 2013 using the zonal mean total ozone (TOZ) data in latitude band from 5° S to 5° N derived from satellite measurements by means of Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI). The study was performed using strong seasonal regularities of the wind QBO and the discrete variation of the QBO-period revealed earlier. The forecast of the wind QBO evolution made in Gabis (2012) is fully justified. The comparison between predicted and actually observed changes of the height wind structure shows the prominent accordance, which confirms the forecast validity. It is shown that variations of deseasonalized TOZ are in strong coupling with changes of equatorial wind QBO that coincides with the numerous previous researches. However our results contradict the assumption about quite complicated ozone response in the equatorial region due to continuously varying with time relationship between annual and quasi-biennial cycles and irregularly variable wind QBO-period. The total ozone changes actually observed clearly corresponds to the mean ozone variations calculated for different QBO scenarios and aligned according to the sequence of QBO scenarios already occurred in fact. This close association indicates the possibility of forecasting the equatorial total ozone QBO based on the predicted wind QBO.     

Impact of Solar Activity on Stratospheric Ozone and NO2 Observed by Gomos/Envisat

Energetic proton precipitation occurring during solar events can increase the production of odd nitrogen in the upper stratosphere and mesosphere. A very intense solar proton event (SPE) occurred on 28 October 2003. Its impact on the composition of the middle atmosphere was observed in details due to the availability of several space instruments. Here we present GOMOS observations of a strong NO₂increase and a related ozone decrease in the upper stratosphere at north polar latitude. The perturbation of the chemical composition of the stratosphere was observed until the middle of December 2003. A strong NO₂ increase was also observed in the south polar vortex in June-July 2003. It is tentatively attributed to the effect of an SPE with protons of moderate energy occurring on 29 May 2003. If this hypothesis is confirmed, it will imply that the global effect of SPEs on the composition of the stratosphere is underestimated when only strong energy SPEs are considered.     

Temperature and pressure variability in mid-latitude low atmosphere and stratosphere-ionosphere coupling

This study presents the continuation of our previous analysis of variations of atmospheric and space weather parameters above Iberian Peninsula along two years near the 24th solar cycle maximum. In the previous paper (Morozova et al., 2017) we mainly discussed the first mode of principal component analysis of tropospheric and lower stratospheric temperature and pressure fields, which was shown to be correlated with lower stratospheric ozone and anti-correlated with cosmic ray flux. Now we extend the investigation to the second mode, which suggests a coupling between the stratosphere and the ionosphere.This second mode, located in the low and middle stratosphere (and explaining ~7% of temperature and ~3% of geopotential height variations), showed to be statistically significantly correlated with variations of the middle stratosphere ozone content and anti-correlated with variations of ionospheric total electron content. Similar co-variability of these stratospheric and ionospheric parameters was also obtained with the wavelet cross-coherence analysis.To investigate the role of atmospheric circulation dynamics and the causal nature of the found correlations, we applied the convergent cross mapping (CCM) analysis to our series. Strong evidence for the stratosphere-ionosphere coupling were obtained for the winter 2012–2013 that is characterized by the easterly QBO phase (quasi-biennial oscillations of the direction of the stratospheric zonal winds) and a strong SSW (sudden stratospheric warming event). Further analysis (for the three-year time interval 2012–2015) hint that SSWs events play main role in emphasizing the stratosphere-ionosphere coupling.