Influence Of Solar Activity Research Articles

The role of the solar and geomagnetic activity in the etiology of multiple sclerosis: a review of the literature and prospects of research

Despite the great progress in the study of multiple sclerosis (MS), its etiology remains unknown. It is proved that MS occurs in genetically predisposed people under the influence of environmental factors. Among these factors the solar activity (SA) and geomagnetic activity (GA) attract the particular attention. This article presents the review of studies concerning the influence of SA and GA on the incidence and course of MS.

Influence of Solar and Geomagnetic Activity on Sporadic-E Layer over Different Latitude Stations

摘要: 关于地磁和太阳活动对Es层形成的影响，已有研究所得结论不同甚至相互矛盾.为研究太阳和地磁活动对Es层的影响，对4个太阳活动周期（1970-2010年）高中低纬度站点每小时Es层的参数进行了分析.结果表明太阳和地磁活动对Es层形成确实具有影响，而且不同纬度Es层与太阳和地磁活动的相关系数也不相同.同时对Es层各参数对于太阳和地磁活动不同反应的原因进行了解释. 关键词: 偶发E层 / 太阳活动 / 地磁扰动 / 分子离子 / 金属离子

Variations in Solar Cycles 22, 23 & 24 and Their Effect on Earth’s Climate

In the present work, the study of influence of solar activity, cosmic ray intensity and geomagnetic activity on Earth’s climate during solar cycles 22, 23 and 24 has been done. The change in Earth’s climate, specifically the change in the global mean temperature has been associated with the variation of some solar activity indices, cosmic ray intensity and geomagnetic activity indices in the period of 1986-2014 (Till Dec.). The important solar indices that are total solar irradiance (TSI), Sunspot Number (SSN), F10.7 index, Cosmic Ray Intensity (CRI) Kiel (NM), geomagnetic activity indices Auroral Electrojet Index (AE) and aa index, have been presented. The study of the Earth’s climate in relationship with solar activity, cosmic ray intensity and geomagnetic activity has been analysed with variations and correlations. The variations of SSN with CRI are in anti-phase; SSN with F10.7, SSN with TSI, SSN with AE, SSN with aa are in same phase. The correlation of SSN with CRI is strongly negatively correlated; SSN with F10.7, SSN with TSI is strongly positively and SSN with AE, SSN with aa positively correlated to averaging solar cycles 22, 23 and 24. The Earth’s climate will be affected by the solar activity, cosmic ray intensity and geomagnetic activity.

Influence of solar activity on red sprites and on vertical coupling in the system stratosphere–mesosphere

The positive downward propagating streamers of sprites are considered as factors of vertical coupling in middle atmosphere. Sprites are initiated in the lower ionosphere (at 75–85km) and their streamers propagate in the mesosphere and upper stratosphere where the solar activity (SA) can have significant influence. The problem considered by us is whether sprites are sensitive to the solar activity. Different possible ways of such influence are considered. They concern: i) relations between solar activity and the occurrence of sprite-producing lightning discharges; ii) sensitivity of streamer inception to solar variability; iii) 11-year variations of conductivity in the night-time mesosphere and stratosphere during solar cycle due to modulation of the galactic cosmic ray flux by solar activity, which can lead to changes in sprite-driving electric fields, and therefore, in sprites. Accounting for the effects of sprites on minor constituents (in particular NOx), a link between SA level and the che^mical balance in the mesosphere and stratosphere is considered, as well. With respect to this we study by modeling the response of the sprite-driving electric fields to SA variations with the account to a complex of parameters of sprite-producing lightning discharges and atmospheric conductivity. The lightning-driven electric fields needed for streamer propagation show minor dependence on conductivity changes caused by variations in cosmic ray flux during a solar cycle. The long-term changes in sprite's lower boundary by different parameters of lightning discharges and atmospheric conductivity parameters are estimated. During solar minimum, of the vertical dimension of sprites increases by up to 1.5km than those during solar maximum. We estimate also the effect of the reduction of conductivity in thunderclouds with respect to the adjacent air. Reduction of cloud conductivity by a factor of 5–10 leads to larger vertical dimension of sprites due to descending of the sprite lower boundary by up to 5km related to the case of unmodified cloud conductivity. The solar variability has significantly bigger effect on the sprite vertical dimension by larger charge moment change of the parental lightning discharge and by large reduction of the cloud conductivity.

Trends of ice breakup date in south‐central Ontario

AbstractLarge‐scale ice phenology studies have revealed overall patterns of later freeze, earlier breakup, and shorter duration of ice in the Northern Hemisphere. However, there have been few studies regarding the trends, including their spatial patterns, in ice phenology for individual waterbodies on a local or small regional scale, although the coherence of ice phenology has been shown to decline rapidly in the first few hundred kilometers. In this study, we extracted trends, analyzed affecting factors, and investigated relevant spatial patterns for ice breakup date time series at 10 locations with record length ≥90 years in south‐central Ontario, Canada. Wavelet methods, including the multiresolution analysis (MRA) method for nonlinear trend extraction and the wavelet coherence (WTC) method for identifying the teleconnections between large‐scale climate modes and ice breakup date, are proved to be effective in ice phenology analysis. Using MRA method, the overall trend of ice breakup date time series (1905–1991) varied from earlier ice breakup to later ice breakup, then to earlier breakup again from south to north in south‐central Ontario. Ice breakup date is closely correlated with air temperature during certain winter/spring months, as well as the last day with snow on the ground and number of snow‐on‐ground days. The influences of solar activity and Pacific North American on ice breakup were comparatively uniform across south‐central Ontario, while those of El Niño–Southern Oscillation, North Atlantic Oscillation, and Arctic Oscillation on ice phenology changed with distance of 50–100 km in the north‐south direction.

Variations in meteor heights at 22.7°S during solar cycle 23

The meteor radar measurements obtained at Cachoeira Paulista (22.7°S), Brazil, have been used to study a possible relationship between meteor echo height variations and solar flux during solar cycle 23. A good concordance between the normalized values of the annual mean of the meteor peak heights and F10.7 solar radio flux and Mg_II solar indexes have been observed during declining phase of the solar cycle 23. After eliminating the solar activity influence, the annual mean of the meteor echo peak heights showed a linear decrease of 30m/year when Mg_II solar index is used and 38m/year when F10.7 solar radio flux is used. When the trend is eliminated the relationship between meteor peak heights and F10.7 solar flux indicate a trend of 672m/100sfu (sfu-solar flux unit). The meteor amplitude signals and the decay time drops after mid-2004, which may be attributed to the decreasing of the electron density in the meteor trails. The meteor echo peak height decrease has been interpreted as being caused by a reduction in air density in the upper atmosphere.

Influence of the QBO and solar activity on interannual variability of the spring-time transition of stratosphere circulation

In this paper the influence of solar activity on variability of the springtime transition dates of stratospheric circulation is investigated. To detect the influence, the springtime transition and solar activity datasets were grouped according to the phases of the Quasi-Biennial Oscillation (QBO). It was obtained that there is a dependence of spring transition dates on solar activity. In case of dividing data on early and later spring transition, the stronger influence of solar signal is revealed at late spring transition. It was also shown that under high solar activity conditions, the relation between spring transition dates and solar activity is stronger than at low one.

Influence of solar activity on seasonal variations of methane absorption in the atmosphere of Saturn

Seasonal variations of methane absorption distribution over the disk of Saturn at the levels of visible clouds and an overcloud haze have been found from the results of observations in the period from 1965 to 2011. The meridional behavior of the methane absorption at the equinox moments in 1966 and 1995 is opposite in phase to the analogous data obtained at the equinox in 1980. During the equinox in 2009, no difference in the methane absorption (expected to be analogous to that in 1980) between the southern and northern hemispheres at the mid latitudes of Saturn were observed, though all of the physical and orbital characteristics of Saturn at the equinox moments in 1966 and 1980, as well as in 1995 and 2009, are practically the same. Several years before the equinoxes in 1966, 1980, and 1995, the solar activity was rather high, while the Sun was in its minimum activity before the 2009 equinox. As has been shown, the dynamic time scale in the mid troposphere of Saturn may be of several dozens of hours if the condensation and convection are accounted for. In this case, large changes of the insolation in the UV spectral range may yield substantial short-term dynamical changes. At the equinox in 2009, convection in the atmosphere of Saturn was as low as possible; because of this, the deep cloud layers in the winter northern hemisphere remained “frozen” after the emersion from the rings’ shadow, while there were practically no active processes on the Sun. Due to this, the low-active cloud layer that had been shadowed before by the rings remained at the same level below the tropopause. This allowed a thick overcloud layer of gaseous methane and ammonia to be easily detected. Because of this, in the low-active hemisphere, where there had been winter before, the methane absorption remained practically the same and equal to the absorption in the hemisphere, where there had been summer before.

Analysis of the Long-Term Vibration of Jianghuai Meiyu in Response to Solar Activity Factor

Take the solar activity as the external forcing factor of the earth' s climate,use wavelet analysis and cross wavelet analysis method, to research the relationship betw een the sunspot numbers and Meiyu in Changjiang-Huaihe River region,and the west Pacific subtropical high indices. The results show that the correlation betw een solar activity and Meiyu exists difference betw een the north,show positive correlation,and the south,show negative correlation. That is to say,during the high sunspot number years,the rainfall in the north area of Changjiang-Huaihe River region would markedly increase,meanw hile,the south area would decrease.Furthermore,the positive and negative correlation remains unchanged in time series. In the south part,M eiyu precipitation and the sunspot numbers has stable resonance cycle in 11 years,and Meiyu lag the sunspot numbers for about 0. 5 ~ 1 year. The western Pacific subtropical high indices and the sunspot numbers also have good correlation. During the high sunspot number years,the subtropical high is shifted more southw ard and stronger,and the square is larger,or vice versa. That means the process chain of solar activity-western Pacific subtropical high-M eiyu in Changjiang-Huaihe River region may be exist in the influence of solar activity on the climate.

Influence of solar activity on global large rivers runoff trends

The physical basis of the influence of solar activity on the climate is evident. The sun’s heat and light energy warms the land surface and oceans and they radiate heat back into the air above. It is believed that increase of solar activity leads to a rise in atmospheric temperature, intensification of the hydrological cycle and consequently to an increase in river flow. The impacts of climate change have led to an increase in global and continental runoff in the last century (Labat et al. 2004). Observations also show a long-term increase trend of solar activity over the period 1855–1996 (Krivova and Solanki 2004). This phenomenon initiated a project to test the hypothesis: influence of solar activity on rivers discharge.

Link of volcanic activity and climate change in Altai studied in the ice core from Belukha Mountain

In the present research we discuss a role of volcanic activity in Altai thermal regime. Here we analyses the sulfate and temperature data reconstructed from the natural paleoarchive – ice core from the Belukha Mountain saddle. Sulfate ice-core reconstructions can serve as volcanic markers. The both – sulfate and temperature reconstructions – are for the last 750 years. As the characteristic of volcanic activity we consider Volcanic Explosivity Index (VEI), Dust Veil Index (DVI) and Ice core volcanic index (IVI). The analysis was done using wavelet analysis and analysis of wavelet cross coherence and phase. As the result, we conclude that observed increases in the values of the indexes VEI, DVI, IVI basically correspond to decreases of temperature and increases of sulfate concentrations. This confirms the dependence of changes in the thermal regime of the Altai from volcanic activity. But in the 1750–1850 years period there is a delay of the changes in temperature with respect to the changes in volcanic activity. We suggest that it can be due to the superposition of the influence of solar and volcanic activity on changes in the thermal regime of Altai.

Methodical Bases for Developing Predictive Scenarios of Agribusiness

Complexity of the agricultural business tasks, high dynamism and non-linear nature of the contemporary socio-economic processes which differs functioning of any industry are placing new requirements for predictive studies. The purpose of this study is to develop a set of methodological provisions for the construction of predictive scenarios of the agricultural business by identifying current trends, the impact factors of the environment and the interpretation of results forecasting and analytical calculations. This article considers the influence of climatic factors on the economic impact of the frumentaceous and the grape branches of agriculture. The system of economic and mathematical prognostics models of the main industrial indicators was developed. The methodology for scenario forecasting of indicators of frumentaceous production and vine growing was proposed based on the use of the influence of solar activity on agrobiological processes.

The influence of solar activity on action centres of atmospheric circulation in North Atlantic

Abstract. We analyse the response of sea level pressure and mid-tropospheric (500 hPa) geopotential heights to variations in solar activity. We concentrate on the Northern Hemisphere and North Atlantic in the period 1948–2012. Composite and correlation analyses point to a strengthening of the North Atlantic Oscillation and weakening (i.e. becoming more zonal) of the Pacific/North American pattern. The locations of points with lowest and highest sea level pressure in the North Atlantic change their positions between low and high solar activity.

The shape of the Venusian bow shock at solar minimum and maximum: Revisit based on VEX observations

Several factors control the bow shock position at Venus, including short-term period responses (solar wind dynamic pressure) and long-term period variations (solar activity). Based on Venus Express (VEX) observations, we revisit the influence of solar activity on the Venusian bow shock location, by accurately determining not only the shock terminator distance but also the subsolar point with a three-parameter fit (TPF) method. At the same time, VEX covers a larger range of solar zenith angles (SZA) at the Venusian bow shock (from about 10 to 135 degrees) than the Pioneer Venus Orbiter (PVO) spacecraft. Fitting results display that the Venusian bow shock is farther away from Venus at solar maximum than at solar minimum. The subsolar stand-off distance increases from 1.364 planetary radii at solar minimum to 1.459RV at solar maximum, while the terminator shock distance changes from 2.087RV to 2.146RV. Inspection of the bow shock and the induced magnetosphere boundary (IMB) locations clearly shows a positive correlation for every orbit, while the average bow shock location is not responsive to changes in the solar wind dynamic pressure.

Seasons on Saturn. II. Influence of solar activity on variation of methane absorption

Seasons on Saturn. II. Influence of solar activity on variation of methane absorption

On the influence of solar activity on the mid-latitude sporadic E layer

To investigate the influence of solar cycle variability on the sporadic E layer (Es), hourly measurements of the critical frequency of the Es ordinary mode of propagation, fo Es, and of the blanketing frequency of the Es layer, fb Es, recorded from January 1976 to December 2009 at the Rome (Italy) ionospheric station (41.8° N, 12.5° E), were examined. The results are: (1) a high positive correlation between the F10.7 solar index and fo Es as well as between F10.7 and fb Es, both for the whole data set and for each solar cycle separately, the correlation between F10.7 and fb Es being much higher than the one between F10.7 and fo Es; (2) a decreasing long-term trend of the F10.7, fo Es and fb Es time series, with fo Es decreasing more rapidly than F10.7 and fb Es; (3) clear and statistically significant peaks at 11 years in the fo Es and fb Es time series, inferred from Lomb-Scargle periodograms.

The influence of solar activities an occurrence of the forest fires in South Europe

In mid-July 2012, hundreds of fires spread over forest stands in the south of Europe. Considering available satellite and meteorological data we have tried to determine a method using analogy, whether these fires were preceded by the intensified solar activity. The justification of this approach lies in the belief that it is impossible by direct or indirect activity of man to set fire at the same time to the sites that are geographically separated. In this paper we have tried to test the hypothesis claiming that charged particles coming to us from the Sun may be responsible for the number of forest fires. Unlike some other situations when the potential explanation could be a sudden influx of the protons of different energy ranges, in our study, there are electrons as carriers of the potential explanation. Many previous studies results have shown that there is statistically significant relationship between the processes on the Sun and certain movements of air masses in the atmosphere our planet. The presented results in this paper of the correlation relationships between the mean hourly flows of electrons and the mean hourly air temperatures in Belgrade and Rome and the analysis of the synoptic situation as a function of the suggested model so far, indicate that the number of fires that were occurring more than a week, from July 15, 2012, in the south of Europe, were caused by electrons coming from the Sun.

Influence of solar and geomagnetic activity on sporadic-E layer over low, mid and high latitude stations

To study the influence of solar and geomagnetic activity on Es layers over low, mid and high latitude stations, hourly values of parameters of Es layer during four solar cycles (1970–2010) over different latitude stations are considered. It has been suggested that there is a relationship between solar and geomagnetic activity with Es layer, and the correlations are different over low, mid and high latitude stations. The reasons of different behavior of Es frequency parameters to solar and geomagnetic activity are also studied.

Study of the cosmogenic factors influence on temporal variation of 7Be air concentration during the 23rd solar cycle in Málaga (South Spain)

Atmospheric 7Be activity concentrations were measured in Malaga (South Spain) during the period 1997–2007. Monthly concentrations of 7Be ranged between 2.47 and 8.12 mBq m−3 showing seasonal trend with maxima in spring–summer time. Influence of solar activity, cosmic rays and aerosol optical depth on airborne 7Be was analyzed. Weak negative correlation between sunspot number and 7Be is found. Instead, both solar energetic protons >100 MeV and cosmic rays show positive weak significant correlation with this radionuclide. Meteorology may contribute to the low correlation coefficients found. Aerosol optical depth exhibits significant correlation with 7Be, confirming that this radionuclide attaches to atmospheric particles.

Influence of solar activity on the climate change

We discuss problems which are of main importance for understanding the nature of climate changes in the 20th century and basic physical processes responsible for these changes. A possible role of solar activity in the Earth’s climate changes in the past and future is considered. As shown, physical mechanisms which can provide for the solar variability effect on the weather and climate are reduced to the control of the energy flux from the Earth to space. A special emphasis is given on the solar activity effect on climatic characteristics of the troposphere through the atmospheric electricity. We consider peculiarities of the response of thermal and dynamic regimes of the World Ocean and atmosphere to solar activity changes and processes in the atmosphere, ocean, and cryosphere. We also show and discuss results of the analysis of regularities and peculiarities of troposphere and the ocean surface temperature response to both isolated heliogeophysical disturbances and long-term changes in solar and geomagnetic activity.