THE CONNECTION OF SECULAR VARIATION OF SOLAR ACTIVITY, ATMOSPHERE CIRCULATION AND AIR TEMPERATURE OF NORTHERN HEMISPHERE

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1 THE CONNECTION OF SECULAR VARIATION OF SOLAR ACTIVITY, ATMOSPHERE CIRCULATION AND AIR TEMPERATURE OF NORTHERN HEMISPHERE T.E.Val chuk 1, N.K.Kononova 2 1 Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) RAS, Troitsk of Moscow region, , Russia, valchuk@izmiran.ru; 2 Institute of Geography RAS, Moscow, Russia Abstract. The main feature of the retrospective analysis of solar activity (SA) and geomagnetic activity (GA) for the period XIX- XXI centuries is the presence of century minima in SA and geomagnetic disturbance. During the mentioned period the reliable and detailed data of measurements are available already, both solar activity and geomagnetic field. Series of indices are reflecting the SA variations (Wolf numbers) and GA (Kp, aa, Dst). Indices reveal secular minima and features of a cyclic recurrence of solar and geomagnetic parameters. It is necessary to tell that Sun action on magnetosphere-ionosphere system and physical mechanisms of solar influence on the upper atmosphere of the Earth are investigated deeply and in details. Weather transformations in troposphere of the Earth occur thanks to solar energy supply. We know, that the complicated chain of a solar energy supply from the Sun to troposphere is investigated much less. However, global and regional characteristics of weather, seasonal features and the extreme weather phenomena are registered and studied. A basis of all events in troposphere is large-scale regional circulation of air mass. Typification of elementary circulating mechanisms (ECM) is developed for Northern hemisphere of the Earth at Institute of Geography RAS. Calendar ECM during ( is used in the present work for revealing of communications of weather with SA and GA. The prehistory was analysed on the basis of global temperature anomaly, ECM in Northern hemisphere and solar-terrestrial communications. The variant of future development of weather transformations in the next decade is presented. INTRODUCTION Historical representation about solar activity, which was defined by quantity and the sizes of active regions (AR) on a visible solar disk, is represented now as insufficient for understanding and interpretation of influence of the Sun on the Earth. Now the concept of solar activity unites the set of the observations connected with energy transformations on the Sun. Energy transformations have continuous character. First of all they are connected with hierarchy of solar magnetic fields. The cyclic character of solar magnetic fields, characteristic variations of powerful fields of sunspots and change of large-scale background magnetic fields, magnetic fields of the upper atmosphere of the Sun (coronal fields) have the various time characteristics. The 22-year-old cycle of a quasi-dipole general magnetic field of the Sun is restoring an initial configuration after two sunspot 11-year-old cycles. Background magnetic fields remain during many Carrington rotations (CRs). Fields of active regions live during one or several CRs. The sporadic events, connected with powerful realizations of energy, occur during the short time measured by a split second, seconds and minutes. Solar energy flows out three-dimensional space of a heliosphere in the form of radiations of all electromagnetic range (infra-red, radio, visible light, an ultraviolet and a X-rays, cosmic rays) and a stream of a solar wind (SW). SW represents a flow of plasma with interplanetary magnetic field (IMF). This stream runs away from the Sun continuously. Outside of 10 R Sun the direction of SW escaping has radial flowing. SW is non-uniform in the presence of sporadic displays of flares or coronal mass ejections (CME) on the Sun. Coronal holes generate high speed SW. Co-rotation interaction regions (CIR) in SW flows disturb the geo-magnetosphere. The Earth accepts only little part of the energy of the Sun from these two agents (radiation and SW), but nevertheless all subsequent weather changes are defined by energy balance in own gaseous geo-spheres. Geomagnetic disturbance characterizes solar influence on magnetosphere and ionosphere of the Earth on-line. Ionospheric current systems change under the action of ionizing radiation. SW flows over geomagnetosphere, changing characteristics of magnetosphere plasma regions. Powerful SW influences cause the great magnetic storms, on power comparable to energy of a cyclone. The troposphere forms own largescale movements in lower layers of atmosphere. Movements are the result of existence of low and high

2 atmospheric pressure regions accordingly cyclones and anticyclones. Atmospheric circulation is the valuable characteristics of weather. The work problem consists in the following: 1) on the basis of the circulation data, global temperature, solar and geomagnetic activity indices to study an interconnections among them; 2) to study features of minimum of 23-th solar cycle; 3) to give the forecast of variations of weather for prospect. AVAILABLE DATA The longest series of sunspot generation is named Wolf number series. It is defined as W = 10 g + f, where g is the quantity of sunspot groups and f is total quantity of spots. This numerical and simple row is used widely, as the complex solar activity has not more uniform and long representation. W and geomagnetic indices aa are presented on Fig aa W 150 aa index and W (line) Years Fig.1 Yearly values of W and geomagnetic indices aa. They are not similar to each other, but minima in W and aa in general features are the same. We look secular minima in the beginning and in the end of graphs. Historical data say that at the beginning of XVIII and XIX centuries were marked deep minima: in 1711 and 1712 W=0, in 1810 W= 0. The analysis of annual values of sunspot numbers W shows that the least values in last century were marked in 1913 (W=1.4, solar cycle minimum 14). The aa index, calculated since 1868, has appeared of minimal value aa= 8.6 nt in 1913 too. Throughout three centuries secular minima of solar activity had place in the beginning of the century. Such prolonged 23-th solar activity minimum we have at the present time. In maxima of 11-year-old SA cycles we see discrepancy between SA and GA also. All the matter is that not everyone AR generates sporadic powerful flare events. Additionally the Earth in the orbital movement will accept only the part of flare events, which are generated in the central part of a visible disk of the Sun. Solar activity in area of helio-projection of the Earth at the account of time of passage of distance from the Sun to the Earth (1 AU), predicts SW, which is coming to the Earth. The knowledge of space weather allows a forecast of SW in an orbit of the Earth. Extreme cases of magnetosphere extra-storms, as October - November 2003, are carefully investigated in search of concrete situations in weather on the Earth

3 Results inspire, but no more that. The physical mechanism of weather formation is difficult, but «the thermal mechanism» is working in troposphere very effectively. We pass to discussion of weather features. The analysis of Northern hemisphere atmosphere circulation in typification of B.L. Dzerdzeevsky, V.M. Kurganskaja and Z.M. Vitvitskaja, conducted since 1899, has shown the following result. In the beginning of last century circulating mechanisms with powerful cold arctic intrusions existed simultaneously in several sectors of Northern hemisphere. On the Northern pole the anticyclone was situated, this arctic anticyclone formed the strips of a high pressure to subtropical anticyclones. Therefore the western zonal carrying over was blocked. Total duration of such processes was the greatest in 1915 (278 days). The analysis of average temperature of air of Northern hemisphere, look Fig.2, data on which are available since 1850, has shown that the lowest average annual temperature was marked in 1917 (the deviation from average for equals -0,544 ºС). It is natural, since advancement to the south of arctic air should lead to a cold snap with inevitability. Thus, the chain is built: a minimum of solar activity (1913) a maximum of blocking processes (1915) a minimum of average annual temperature of air on Northern hemisphere (1917). Fig.2. Temperature anomaly, hemispheric and global averages graph. (

4 In the end of XX century the solar activity minimum covered and was deep. In 1997 total duration of circulation groups with two and more blocking processes on Northern hemisphere was prolonged only 147 days. Since 1998 growth of blocking process duration has begun. In the beginning of XXI century the prolonged minimum of solar activity proceeded per In 2009 total duration of blocking process amounted to 265 days it exceeds average value for 70 days, Table 1. Year Duration in days Deviation from average for For comparison Table 1. Blocking process duration in The maximum of average annual temperature of air on Northern hemisphere was marked in 2005; a deviation has made 0,626 ºC. Since this year the temperature has started to go down gradually, and in 2009 the deviation has made already 0,518 ºC. DISCUSSION AND CONCLUSIONS Analysis of the long-term series of annual duration of zonal, northern meridional and southern meridional circulation groups from 1899 to the present tense, which has been carried out in Institute of Geography RAS, has shown the availability of 3 circulation epochs: 1) Northern meridional epoch ( ). 2) Zonal epoch ( ). 3) Southern meridional epoch ( ). However since 1998 the duration of meridional southern processes began quickly to decrease, and meridional northern to increase, therefore by 2007 duration of both groups appeared above average. Such parity of circulation groups was marked in This period is known for some downturn of average global air temperature. Not casually researches have been dated for this period under the program of the International Geophysical Year. Change of a ratio of meridional southern and northern groups is reflected in a parity of cyclonic and anti-cyclonic circulation in any region, in particular, in Arctic regions [1-4]. The duration of high pressure on North Pole increases recently. Our results were considered in connection with solar cycle recurrence and geomagnetic activity. The solar cycles (the last southern meridional epoch) demonstrate the different character of fluctuation of northern meridional and southern meridional circulation groups in even and odd cycles. Fig.3 shows the behavior of yearly Wolf s numbers, northern (N) meridional and southern (S) meridional circulation and aaindices in all over period The duration of southern meridional circulation group is growing in 19,20,21 and 22 cycle minima, the sharp decrease we look only in last years in 23-th deep solar minimum. Now, up to autumn 2010, solar and geomagnetic activities are very low. If the tendency will be steady northern meridional epoch will prevail.

5 Fig.3 W, aa and N and S meridional circulation (days in year) YEAR OF EXTREME WEATHER Repeatability of the extreme situations connected with weather conditions in Russia has important practical value. The hot and smoky summer of 2010 reminded most of all the summer of Duration of cyclonic circulation on the North Pole and the carrying over of warm and damp air from Mediterranean sea in middle and northern latitudes since 1998 on Northern hemisphere has started to decrease [5]. Duration of powerful Arctic anticyclones began to increase at the same time. It provides intrusions of cold air at the winter and formation of steady anticyclones with droughty weather in the summer. This situation 2010 was expressed in the summer in absolute plural daily temperature maxima. The drought has generated fires from which the Central Russia and other regions suffered. Extreme weather events we will consider in comparison to a global variation of temperature. Global warming has ended since 1998 presumably. Warming was characterized by frequent thaw in the winter and rainy cool summer seasons, though its termination wasn't simultaneous on all Earth. On the average in Russia, for example, 2007 has appeared as the warmest year was the warmest previous: the average temperature of 1995 was only on 0,03ºС lower, than in Practically since 1995 warming has stopped in territory of Russia on the average. References 1. Kononova N.K. (2003). Fluctuations of Northern Hemisphere atmospheric circulation in , Proceedings of the International Conference Mathematical Methods in Geophysics. Novosibirsk. Inst. of Comp. Math. And Math. Geoph. Publ. Part II, Val chuk T.E, Kononova N.K., Chernavskaya M.M. (2002). Climatic changes over 102 years period: helio- and geomagnetic parameters in connection with the North Hemisphere tropospheric circulation, Proceedings of 4-th International Conference Problems of Geocosmos, Chernavskaya M.M., Kononova N.K., Val`chuk T.E. (2006). Correlation between atmospheric circulation processes over the Northern Hemisphere and parameter of solar variability during , Advances in Space Research, 37(8), T.E. Val chuk, N.K. Kononova. (2009). The Tendency to Atmosphere Circulation Epoch Change in the beginning of XXI century, Proceedings of Russian annual conference on physics of the Sun, S- Pb, GAO RAS Press, Kononova N.K. (2009) Classification of circulating mechanisms of Northern hemisphere by B.L.Dzerdzeevsky, Ed. A.B.Shmakin; RAS, IG RAS Мoscow: Voentexizdat, 372 p.