The Effect of Solar Activity on the Annual Precipitation in the Beijing Area

Using continuous wavelet transform, we examine the relationship between solar activity and the annual precipitation in the Beijing area. The results indicate that the annual precipitation is closely related to the variation of sunspot numbers, and that solar activity probably plays an important role in influencing the precipitation on land.     

Total ozone response to major geomagnetic storms and changes in meteorological situations

Summary The total ozone response to strong major geomagnetic storms (A_p≥60) in winter along the 50° N latitudinal circle is studied. The results add to the recent results of Laštovička et al. (1992) obtained for European middle latitudes (∼50°N) and to the results of Mlch (1994). A significant response of total ozone is only observed in winter under high solar activity/E-phase of QBO conditions (E-max) and seems to be caused by geomagnetic storm-induced changes of atmospheric dynamics. There are two sectors along latitude 50°N, which are sensitive to forcing by geomagnetic storms both in total ozone and the troposphere — north-eastern Atlantic-European and eastern Siberia-Aleutian sectors. The total ozone response under E-max conditions manifests itself mainly as a large decrease in the longitudinal variation of ozone after the storm, which means an increase of ozone in Europe. The observed effects in total ozone consist in redistribution, not production or loss of ozone.     

Solar radiative output and its variability: evidence and mechanisms

Electromagnetic radiation from the Sun is Earths primary energy source. Space-based radiometric measurements in the past two decades have begun to establish the nature, magnitude and origins of its variability. An 11-year cycle with peak-to-peak amplitude of order 0.1 % is now well established in recent total solar irradiance observations, as are larger variations of order 0.2 % associated with the Suns 27-day rotation period. The ultraviolet, visible and infrared spectral regions all participate in these variations, with larger changes at shorter wavelengths. Linkages of solar radiative output variations with solar magnetism are clearly identified. Active regions alter the local radiance, and their wavelength-dependent contrasts relative to the quiet Sun control the relative spectrum of irradiance variability. Solar radiative output also responds to sub-surface convection and to eruptive events on the Sun. On the shortest time scales, total irradiance exhibits five minute fluctuations of amplitude %, and can increase to as much as 0.015 % during the very largest solar flares. Unknown is whether multi-decadal changes in solar activity produce longer-term irradiance variations larger than observed thus far in the contemporary epoch. Empirical associations with solar activity proxies suggest reduced total solar irradiance during the anomalously low activity in the seventeenth century Maunder Minimum relative to the present. Uncertainties in understanding the physical relationships between direct magnetic modulation of solar radiative output and heliospheric modulation of cosmogenic proxies preclude definitive historical irradiance estimates, as yet.Received: 26 August 2004, Published online: 16 November 2004 Correspondence to: Claus Fröhlich     

A Statistical Study on the Geomagnetically Induced Current Events Driven by Earth-directed Full-Halo Coronal Mass Ejections

Solar activities can cause the anomalies of electric power transmission systems, especially, for an extra-long distance transmission system. Using the data of coronal mass ejection (CME) from SOHO/LASCO (Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph), and the data of the geomagnetically induced current (GIC) and geomagnetic storm from the North China Electric Power University and Finnish Meteorological Institute, respectively, we analyze some important observational features and physical properties of the earth-directed halo CMEs associated with the GIC events. After classifying the observed halo CMEs according to their symmetry, it is found that the halo CMEs associated with GIC events are mainly the 3 types: completely symmetric, brightness-asymmetric, and outline-asymmetric. The geomagnetically induced current events driven by the three different types of halo CMEs have different characteristics in the intensity, duration, and period. We ?nd that the brightness-asymmetric halo CMEs are most likely to cause the major damage to the transmission systems. And that the geomagnetically induced current has also a good correlation with the time variation of geomagnetic ?eld.     

Redefining the limit dates for the Maunder Minimum

The Maunder Minimum corresponds to a prolonged minimum of solar activity a phenomenon that is of particular interest to many branches of natural and social sciences commonly considered to extend from 1645 until 1715. However, our knowledge of past solar activity has improved significantly in recent years and, thus, more precise dates for the onset and termination of this particularly episode of our Sun can be established. Based on the simultaneous analysis of distinct proxies we propose a redefinition of the Maunder Minimum period with the core “Deep Maunder Minimum” spanning from 1645 to 1700 (that corresponds to the Grand Minimum state) and a wider “Extended Maunder Minimum” for the longer period 1618–1723 that includes the transition periods.     

日地系统研究的现状和趋势

日地系统研究的发展趋势是将日地系统各圈层作为一个整体来开展三维的定量研究，发展各国之间和各学科之间科学家的广泛合作，加强空间探测和地面综合监测网的建设，密切观测分析、理论研究、数值模拟和环境预报之间的联系，直接为生存和生产服务．     

The Global Atmospheric Electrical Circuit and Climate

Evidence is emerging for physical links among clouds, global temperatures, the global atmospheric electrical circuit and cosmic ray ionisation. The global circuit extends throughout the atmosphere from the planetary surface to the lower layers of the ionosphere. Cosmic rays are the principal source of atmospheric ions away from the continental boundary layer: the ions formed permit a vertical conduction current to flow in the fair weather part of the global circuit. Through the (inverse) solar modulation of cosmic rays, the resulting columnar ionisation changes may allow the global circuit to convey a solar influence to meteorological phenomena of the lower atmosphere. Electrical effects on non-thunderstorm clouds have been proposed to occur via the ion-assisted formation of ultra-fine aerosol, which can grow to sizes able to act as cloud condensation nuclei, or through the increased ice nucleation capability of charged aerosols. Even small atmospheric electrical modulations on the aerosol size distribution can affect cloud properties and modify the radiative balance of the atmosphere, through changes communicated globally by the atmospheric electrical circuit. Despite a long history of work in related areas of geophysics, the direct and inverse relationships between the global circuit and global climate remain largely quantitatively unexplored. From reviewing atmospheric electrical measurements made over two centuries and possible paleoclimate proxies, global atmospheric electrical circuit variability should be expected on many timescales.     

Verification of a Similar Cycle Prediction for the Ascending and Peak Phases of Solar Cycle 23

Reviews of long-term predictions of solar cycles have shown that a precise prediction with a lead time of 2 years or more of a solar cycle remains an unsolved problem. We used a simple method, the method of similar cycles, to make long-term predictions of not only the maximum amplitude but also the smoothed monthly mean sunspot number for every month of Solar Cycle 23. We verify and compare our prediction with the latest available observational results.     

近200年来全球地震活动与月相及地球自公转的关系分析

对1811-2008年近200年来全球地震活动与月相、日地距离、地球自转速度这三个天文因素的统计分析表明,月相不论与全球地震还是全球大地震之间似乎无统计关系,全球地震的发生与日地距离似乎无统计关系。本文还进一步对全球M≥7．5的大地震进行了统计,结果表明M≥7．5的大地震与地球处于近日点似乎有一定的关系,但关系不太明显。全球除了8．0〉M≥7．0的地震基本上符合发震的自然概率外,在M≥9．0、9．0〉M≥8．0、6．0〉M≥5．0、4．0〉M≥3．0这些震级段地震发生的机率在地球自转减速期比较小,在地球自转加速期发生的机率比较大,似乎地球自转速度的变化对全球地震活动有一定的促发作用,但不明显。     

Spatial Structure and Long-Term Variations of The Ground-Level Temperature Variance

The global distribution of the ground-level temperature variance and its long-term variations have been investigated on the basis of the monthly mean temperature anomalies, obtained from ground-based and sea-borne meteorological observations from 1896 to 1990. Particular characteristics of the large-scale structure of the temperature variance have been found. There are three pronounced maxima in the global distribution of the temperature variance: in Central Siberia (60°75°N and 70° 120°E), North America (60°75°N and –170°–120°E) and the Antarctica (50°65°S and –60°10°E, where and are the geographic latitude and longitude, respectively) and there are two minima: over the Atlantic and Pacific Ocean areas. The minimum over the Pacific is not as pronounced, as over the Atlantic. The spatial pattern of the ground-level temperature variance is, on the whole, stable, the positions of the zones of extrema remaining practically unchanged over a long time interval. These results indirectly corroborate the mechanism of solar impact on the properties of the low atmosphere by the modulation of the flux of galactic cosmic rays. The mechanism accounts for the spatial distribution of the temperature variance as a result of combined effect of solar activity and ocean. Long-term variations of the Siberian maximum of the ground-level temperature variance agree with the changing duration of the sunspot cycle, in contrast to the North American maximum.