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Sample records for solar activity influences

  1. Influence of solar activity on climate change

    NASA Astrophysics Data System (ADS)

    Kirichenko, Kirill; Kovalenko, Vladimir

    The questions of primary importance for understanding the nature of climate changes in the XX century and main physical processes responsible for these changes are discussed. A physical model of the influence of solar activity on climate characteristics is presented. A key concept of this model is the influence of heliogeophysical disturbances on the Earth's climate system parameters controlling the long-wave radiation flux going out into space in high-latitude regions. A change in the Earth's radiation balance of high-latitude regions induces restructuring of the tropospheric thermobaric field, changes in the meridional temperature gradient responsible for meridional heat transfer. This causes changes in the heat content of the Earth's climate system and global climate. We present and discuss results of analysis of regularities and peculiarities of tropospheric and sea surface temperature (SST) responses both to separate heliogeophysical disturbances and to long-term changes of solar and geomagnetic activity. It is established that the climatic response in the tropospheric and sea surface temperature to the effect of solar and geomagnetic activity is characterised by a significant space-time irregularity and is local. A distinguishing feature of these distributions is the presence of regions of both positive and negative correlations. The exception is the epoch (1910-1940) when the SST response to geomagnetic activity was positive in virtually all regions, i. e. was global. This epoch coincides with the longest period of increase in geomagnetic activity during the period considered at the end of which annual averages of geomagnetic activity exceeded maximum values at the beginning of the epoch. Key words: climate, ocean, troposphere, solar activity.

  2. Influence of solar activity on Jupiter's atmosphere

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.

    2016-05-01

    The influx of solar energy to different latitudes while Jupiter's orbital motion around the Sun varies significantly. This leads to a change in the optical and physical characteristics of its atmosphere. Analysis of the data for 1850-1991 on determination of the integral magnitude Mj Jupiter in the V filter, and a comparison with the changes of the Wolf numbers W, characterizing the variations of solar activity (SA) - showed that the change of Mj in maxima of the SA - has minima for odd, and maximums - for the even of SA cycles. That is, changing of the Jupiter brightness in visible light is much evident 22.3-year magnetic cycle, and not just about the 11.1-year cycle of solar activity. Analysis of the obtained in 1960-2015 data on the relative distribution of brightness along the central meridian of Jupiter, for which we calculated the ratio of the brightness Aj of northern to the southern part of the tropical and temperate latitudinal zones, allowed to approximate the change of Aj by sinusoid with a period of 11.91±0.07 earth years. Comparison of time variation of Aj from changes in the index of SA R, and the movement of the planet in its orbit - indicates the delay of response of the visible cloud layer in the atmosphere of the Sun's exposure mode for 6 years. This value coincides with the radiative relaxation of the hydrogen-helium atmosphere

  3. No evidence for planetary influence on solar activity

    NASA Astrophysics Data System (ADS)

    Cameron, R. H.; Schüssler, M.

    2013-09-01

    Context. Recently, Abreu et al. (2012, A&A. 548, A88) proposed a long-term modulation of solar activity through tidal effects exerted by the planets. This claim is based upon a comparison of (pseudo-)periodicities derived from records of cosmogenic isotopes with those arising from planetary torques on an ellipsoidally deformed Sun. Aims: We examined the statistical significance of the reported similarity of the periods. Methods: The tests carried out by Abreu et al. were repeated with artificial records of solar activity in the form of white or red noise. The tests were corrected for errors in the noise definition as well as in the apodisation and filtering of the random series. Results: The corrected tests provide probabilities for chance coincidence that are higher than those claimed by Abreu et al. by about 3 and 8 orders of magnitude for white and red noise, respectively. For an unbiased choice of the width of the frequency bins used for the test (a constant multiple of the frequency resolution) the probabilities increase by another two orders of magnitude to 7.5% for red noise and 22% for white noise. Conclusions: The apparent agreement between the periodicities in records of cosmogenic isotopes as proxies for solar activity and planetary torques is statistically insignificant. There is no evidence for a planetary influence on solar activity.

  4. How Large Scales Flows May Influence Solar Activity

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.

    2004-01-01

    Large scale flows within the solar convection zone are the primary drivers of the Sun's magnetic activity cycle and play important roles in shaping the Sun's magnetic field. Differential rotation amplifies the magnetic field through its shearing action and converts poloidal field into toroidal field. Poleward meridional flow near the surface carries magnetic flux that reverses the magnetic poles at about the time of solar maximum. The deeper, equatorward meridional flow can carry magnetic flux back toward the lower latitudes where it erupts through the surface to form tilted active regions that convert toroidal fields into oppositely directed poloidal fields. These axisymmetric flows are themselves driven by large scale convective motions. The effects of the Sun's rotation on convection produce velocity correlations that can maintain both the differential rotation and the meridional circulation. These convective motions can also influence solar activity directly by shaping the magnetic field pattern. While considerable theoretical advances have been made toward understanding these large scale flows, outstanding problems in matching theory to observations still remain.

  5. How Large Scale Flows in the Solar Convection Zone may Influence Solar Activity

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.

    2004-01-01

    Large scale flows within the solar convection zone are the primary drivers of the Sun s magnetic activity cycle. Differential rotation can amplify the magnetic field and convert poloidal fields into toroidal fields. Poleward meridional flow near the surface can carry magnetic flux that reverses the magnetic poles and can convert toroidal fields into poloidal fields. The deeper, equatorward meridional flow can carry magnetic flux toward the equator where it can reconnect with oppositely directed fields in the other hemisphere. These axisymmetric flows are themselves driven by large scale convective motions. The effects of the Sun s rotation on convection produce velocity correlations that can maintain the differential rotation and meridional circulation. These convective motions can influence solar activity themselves by shaping the large-scale magnetic field pattern. While considerable theoretical advances have been made toward understanding these large scale flows, outstanding problems in matching theory to observations still remain.

  6. Physical Model of Solar Activity Influence on Climate Characteristics of Troposphere.

    NASA Astrophysics Data System (ADS)

    Molodykh, S. I.; Zherebtsov, G. A.; Kovalenko, V. A.

    2009-10-01

    A new model of solar activity influence on the parameters of the terrestrial climate system is discussed. The main points of the model of solar activity effect on the terrestrial climate system are presented. The key conception of this model is the influence of heliogeophysical disturbances on the terrestrial climate system parameters controlling the energy flux going from the Earth to the space in polar regions. The model is based on the physical mechanism of the influence of heliogeophysical factors on climate characteristics and atmospheric circulation in high-latitude troposphere through atmospheric electricity. According to this model, the growth of solar activity results in the decrease of radiative cooling in high-latitude regions, increase of temperature of lower and middle troposphere, reorganization of the thermobaric field, decrease of the mean meridional gradient of temperature between polar and equatorial regions, which determine the meridional transportation of heat. The decrease of heat flow-out from low-latitude regions results in temperature increase in lower and middle latitude regions, and increase of heat content of the ocean and climate system. Some observational data are presented that confirm the proposed model.

  7. No evidence for planetary influence on solar activity 330 000 years ago

    NASA Astrophysics Data System (ADS)

    Cauquoin, A.; Raisbeck, G. M.; Jouzel, J.; Bard, E.

    2014-01-01

    Context. Abreu et al. (2012, A&A. 548, A88) have recently compared the periodicities in a 14C - 10Be proxy record of solar variability during the Holocene and found a strong similarity with the periodicities predicted on the basis of a model of the time-dependent torque exerted by the planets on the sun's tachocline. If verified, this effect would represent a dramatic advance not only in the basic understanding of the Sun's variable activity, but also in the potential influence of this variability on the Earth's climate. Cameron and Schussler (2013, A&A. 557, A83) have seriously criticized the statistical treatment used by Abreu et al. to test the significance of the coincidences between the periodicities of their model with the Holocene proxy record. Aims: If the Abreu et al. hypothesis is correct, it should be possible to find the same periodicities in the records of cosmogenic nuclides at earlier times. Methods: We present here a high-resolution record of 10Be in the EPICA Dome C (EDC) ice core from Antarctica during the Marine Interglacial Stage 9.3 (MIS 9.3), 325-336 kyr ago, and investigate its spectral properties. Results: We find very limited similarity with the periodicities seen in the proxy record of solar variability during the Holocene, or with that of the model of Abreu et al. Conclusions: We find no support for the hypothesis of a planetary influence on solar activity, and raise the question of whether the centennial periodicities of solar activity observed during the Holocene are representative of solar activity variability in general.

  8. Solar flare acceleration of solar wind - Influence of active region magnetic field

    NASA Technical Reports Server (NTRS)

    Lundstedt, H.; Wilcox, J. M.; Scherrer, P. H.

    1981-01-01

    The direction of the photospheric magnetic field at the site of a solar flare is a good predictor of whether the flare will accelerate solar wind plasma. If the field has a southward component, high-speed solar wind plasma is usually observed near the earth about 4 days later. If the field has a northward component, such high-speed solar wind is almost never observed. Southward-field flares may then be expected to have much larger terrestrial effects than northward flares.

  9. Influence of solar activity on fibrinolysis and fibrinogenolysis. [statistical correlation between solar flare and blood coagulation indices

    NASA Technical Reports Server (NTRS)

    Marchenko, V. I.

    1974-01-01

    During periods of high solar activity fibrinolysis and fibrinogenolysis are increased. A direct correlative relationship is established between the indices of fibrinolysis, fibrinogenolysis and solar flares which were recorded two days before the blood was collected for analysis.

  10. What is the solar influence on climate? Overview of activities during CAWSES-II

    NASA Astrophysics Data System (ADS)

    Seppälä, Annika; Matthes, Katja; Randall, Cora E.; Mironova, Irina A.

    2014-12-01

    This paper presents an overview of the main advances in the Key Questions identified by the Task Group `What is the Solar Influence on Climate' by the SCOSTEP CAWSES-II science program. We go through different aspects of solar forcing from solar irradiance, including total solar irradiance (TSI) and solar spectral irradiance (SSI), to energetic particle forcing, including energetic particle precipitation (EPP) and cosmic rays (CR). Besides discussing the main advances in the timeframe 2009 to 2013, we also illustrate the proposed mechanism for climate variability for the different solar variability sources listed above. The key questions are as follows: What is the importance of spectral variations to solar influences on climate? What is the effect of energetic particle forcing on the whole atmosphere and what are the implications for climate? How well do models reproduce and predict solar irradiance and energetic particle influences on the atmosphere and climate?

  11. The influence of nonstationarity of the solar activity and general solar field on modulation of cosmic rays

    NASA Technical Reports Server (NTRS)

    Zusmanovich, A. G.; Kryakunova, O. N.; Churunova, L. F.; Shvartsman, Y. E.

    1985-01-01

    A numerical model of the propagation of galactic cosmic rays in interplanetary space was constructed for the case when the modulation depth determined by the level of solar activity changed in time. Also the contribution of particle drift in the regular field was calculated, and the agreement with experimental data concerning the ratio of protons and electrons in two solar activity minima is shown.

  12. Solar activity influence on climatic variations of stratosphere and mesosphere in mid-latitudes

    NASA Technical Reports Server (NTRS)

    Taubenheim, J.; Entzian, G.; Voncossart, G.

    1989-01-01

    The direct modulation of temperature of the mid-latitude mesosphere by the solar-cycle EUV variation, which leads to greater heat input at higher solar activity, is well established. Middle atmosphere temperature modulation by the solar cycle is independently confirmed by the variation of reflection heights of low frequency radio waves in the lower ionosphere, which are regularly monitored over about 30 years. As explained elsewhere in detail, these reflection heights depend on the geometric altitude of a certain isobaric surface (near 80 k), and on the solar ionizing Lyman-alpha radiation flux. Knowing the solar cycle variation of Lyman-alpha how much the measured reflection heights would be lowered with the transition from solar minimum to maximum can be calculated, if the vertical baric structure of the neutral atmosphere would remain unchanged. An discrepancy between expected and observed height change must be explained by an uplifting of the isobaric level from solar minimum to maximum, caused by the temperature rise in the mesosphere. By integrating the solar cycle temperature changes over the height region of the middle atmosphere, and assuming that the lower boundary (tropopause) has no solar cycle variation, the magnitude of this uplifting can be estimated. It is given for the Lidar-derived and for the rocket-measured temperature variations. Comparison suggests that the real amplitude of the solar cycle temperature variation in the mesosphere is underestimated when using the rocket data, but probably overestimated with the Lidar data.

  13. Solar influences on global change

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Monitoring of the Sun and the Earth has yielded new knowledge essential to this debate. There is now no doubt that the total radiative energy from the Sun that heats the Earth's surface changes over decadal time scales as a consequence of solar activity. Observations indicate as well that changes in ultraviolet radiation and energetic particles from the Sun, also connected with the solar activity, modulate the layer of ozone that protects the biosphere from the solar ultraviolet radiation. This report reassesses solar influences on global change in the light of this new knowledge of solar and atmospheric variability. Moreover, the report considers climate change to be encompassed within the broader concept of global change; thus the biosphere is recognized to be part of a larger, coupled Earth system. Implementing a program to continuously monitor solar irradiance over the next several decades will provide the opportunity to estimate solar influences on global change, assuming continued maintenance of observations of climate and other potential forcing mechanisms. In the lower atmosphere, an increase in solar radiation is expected to cause global warming. In the stratosphere, however, the two effects produce temperature changes of opposite sign. A monitoring program that would augment long term observations of tropospheric parameters with similar observations of stratospheric parameters could separate these diverse climate perturbations and perhaps isolate a greenhouse footprint of climate change. Monitoring global change in the troposphere is a key element of all facets of the United States Global Change Research Program (USGCRP), not just of the study of solar influences on global change. The need for monitoring the stratosphere is also important for global change research in its own right because of the stratospheric ozone layer.

  14. Solar Influence on Future Climate

    NASA Astrophysics Data System (ADS)

    Arsenovic, Pavle; Stenke, Andrea; Rozanov, Eugene; Peter, Thomas

    2015-04-01

    Global warming is one of the main threats to mankind. There is growing evidence that anthropogenic greenhouse gases have become the dominant factor, however natural factors such as solar variability cannot be neglected. Sun is a variable star; its activity varies in regular 11-years solar cycles. Longer periods of decreased solar activity are called Grand Solar Minima, which have stronger impact on terrestrial climate. Another natural factor related with solar activity are energetic particles. They can ionize neutral molecules in upper atmosphere and produce NOx and HOx which deplete ozone. We investigate the effect of proposed Grand Solar Minimum in 21st and 22nd century on terrestrial climate and ozone layer. The simulations are performed with different solar forcing scenarios for period of 200 years (2000-2200) using global chemistry-climate model coupled with ocean model (SOCOL-MPIOM). We also deal with problem of representation of middle range energy electrons (30-300 keV) in the model and investigation of their influence on climate.

  15. Influence of solar activity on red sprites and on vertical coupling in the system stratosphere-mesosphere

    NASA Astrophysics Data System (ADS)

    Tonev, Peter T.; Velinov, Peter I. Y.

    2016-04-01

    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 75-85 km) 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 1.5 km 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

  16. What are the evidences of solar activity influence on coronary heart disease?

    NASA Astrophysics Data System (ADS)

    Gurfinkel, Yury; Breus, Tamara

    Researches of last two decades have shown that the cardiovascular system represents the most probable target for influence of helio - and geomagnetic activity. Both cardiovascular system and blood connect very closely: one system cannot exist without another. For the same reason the effects perceived by one system, are easily transferred to another. Laboratory tests as blood coagulation, platelet aggregation, and capillary blood velocity performed in our hospital in patients suffering from coronary heart disease (CHD) revealed a high their dependence on a level of geomagnetic activity (Gurfinkel et al., 1995, 1998). Later Gmitrov and Ohkubo (2002) in experiments on animals also found a significant negative correlation between geomagnetic field disturbances and capillary blood velocity. The analyzing data collected by the Moscow ambulance services covering more then one million observations over three years, cleaned up by seasonal effects of meteorological and social causes, showed that the number of cases of myocardial infarction increased during geomagnetic storms (Breus et al., 1995). During 14 years we collected more than 25000 cases of acute myocardial infarction and brain stroke at seven medical hospitals located in Russia, China and some other countries. We used only cases with established date of acute attack of diseases. Undated cases were excluded from the analysis. Average numbers of patients on geomagnetic active days and days with quiet geomagnetic condition were compared. It was shown statistically that during geomagnetic disturbances the frequency of myocardial infarction and brain stroke cases increased on the average by a factor of two in comparison with quiet geomagnetic conditions. These results are close to results obtained by (Stoupel, 1999), for patients suffering with acute cardiological pathology. Our recent study (with L.Parfeonova) revealed the relation between heart ventricular ectopic activity (VEA) and geomagnetic conditions in patients

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

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.

    2015-10-01

    Methane and ammonia in the atmosphere of Saturn are in the form of impurities at the level of less than tenths of a percentage. They take part in photochemical processes, the main products of which are hydrocarbons and ammonia NH3. Polyacetylenes absorb sunlight almost to 400 nm, and hydrocarbons <180 nm. Therefore, the solar activity cycle, the slope of the equator to the plane of the orbit, the orbital motion and the presence of the rings induce change in composition of the upper atmosphere. Radiation constants in the atmosphere depend on the physical and chemical conditions, decreasing from ~10 years at the visible clouds level, to months in tropopause, and days in stratosphere. The observed seasonal effects may be associated also with condensation and convection, and the dynamic time scale may be only tens of hours. The data analysis on the methane absorption distribution over the disk of Saturn for 1964-2012 showed a significant seasonal changes in the levels of visible clouds and above clouds haze. Changes of methane absorption along the meridian in the equinox 1966 and 1995, had the opposite course to the results in equinox 1980. But the expected differences in the change of methane absorption at the equinox 2009, similar to 1980, did not happen. Although all the physical and orbital characteristics of Saturn at equinoxes in these moments repeated, but the response to them were received various. A few years before the equinox in 1966, 1980 and 1995, the number of R, characterizing solar activity, varied from 40 to 180. Before equinox 2009 the Sun has minimal activity and the R value was practically zero. According to observations at the time of equinox 2009, convection in the Saturn's atmosphere stayed at a minimal level. After exiting of rings shadows in winter northern hemisphere deep cloud layer was "frozen" at the same low level at absence of active processes on the Sun. This allowed easily to register a thick layer of methane and ammonia gas. So how

  18. Solar Activity and Solar Eruptions

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.

    2006-01-01

    Our Sun is a dynamic, ever-changing star. In general, its atmosphere displays major variation on an 11-year cycle. Throughout the cycle, the atmosphere occasionally exhibits large, sudden outbursts of energy. These "solar eruptions" manifest themselves in the form of solar flares, filament eruptions, coronal mass ejections (CMEs), and energetic particle releases. They are of high interest to scientists both because they represent fundamental processes that occur in various astrophysical context, and because, if directed toward Earth, they can disrupt Earth-based systems and satellites. Research over the last few decades has shown that the source of the eruptions is localized regions of energy-storing magnetic field on the Sun that become destabilized, leading to a release of the stored energy. Solar scientists have (probably) unraveled the basic outline of what happens in these eruptions, but many details are still not understood. In recent years we have been studying what triggers these magnetic eruptions, using ground-based and satellite-based solar observations in combination with predictions from various theoretical models. We will present an overview of solar activity and solar eruptions, give results from some of our own research, and discuss questions that remain to be explored.

  19. Solar Wind-Magnetosphere Coupling Influences on Pseudo-Breakup Activity

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Brittnacher, M.; Parks, G. K.; Germany, G. A.; Spann, J. F.

    1998-01-01

    Pseudo-breakups are brief, localized aurora[ arc brightening, which do not lead to a global expansion, are historically observed during the growth phase of substorms. Previous studies have demonstrated that phenomenologically there is very little difference between substorm onsets and pseudo-breakups except for the degree of localization and the absence of a global expansion phase. A key open question is what physical mechanism prevents a pseudo-breakup form expanding globally. Using Polar Ultraviolet Imager (UVI) images, we identify periods of pseudo-breakup activity. Foe the data analyzed we find that most pseudo-breakups occur near local midnight, between magnetic local times of 21 and 03, at magnetic latitudes near 70 degrees, through this value may change by several degrees. While often discussed in the context of substorm growth phase events, pseudo-breakups are also shown to occur during prolonged relatively inactive periods. These quiet time pseudo-breakups can occur over a period of several hours without the development of a significant substorm for at least an hour after pseudo-breakup activity stops. In an attempt to understand the cause of quiet time pseudo-breakups, we compute the epsilon parameter as a measure of the efficiency of solar wind-magnetosphere coupling. It is noted that quiet time pseudo-breakups occur typically when epsilon is low; less than about 50 GW. We suggest that quiet time pseudo-breakups are driven by relatively small amounts of energy transferred to the magnetosphere by the solar wind insufficient to initiate a substorm expansion onset.

  20. North-South differences in the Earth's high-latitude upper atmosphere dynamics: Influence of solar activity and seasonal variations

    NASA Astrophysics Data System (ADS)

    Förster, Matthias; Cnossen, Ingrid

    2014-05-01

    Recent observations have shown that the upper thermospheric/ionospheric response to solar wind and IMF dependent drivers of the magnetosphere-ionosphere-thermosphere (M-I-T) system can be very dissimilar in the Northern and Southern Hemisphere. We present statistical studies of the high-latitude upper thermospheric neutral wind circulation patterns obtained from almost a decade of measurements with an accelerometer on board the CHAMP spacecraft. The influence of the solar activity and the dependence on seasonal variations is analysed with respect to average cross-polar wind velocities and high-latitude neutral wind vorticity values. Using the Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model, on the other hand, we simulated representative equinox as well as solstice intervals for low and high solar activity conditions. For the simulations, we used on the one hand side symmetric dipole and on the other realistic (IGRF) geomagnetic field configurations. The comparative survey of both the numerical simulation and the statistical observation results show some prominent asymmetries between the two hemispheres, which are caused by the different geographic-geomagnetic offsets and/or the different patterns of geomagnetic flux densities. The average cross-polar neutral wind velocities show a distinct seasonal variation with minimum values during the respective hemispheric winter solstice. The neutral wind vorticity values are generally larger in the Northern than the Southern Hemisphere, except for northern winter solstice conditions. The hemispheric differences become larger for higher solar activity and show a semidiurnal variation. In contrast, the spatial variance of the upper thermospheric neutral wind is usually considerably larger in the polar region of the Southern Hemisphere compared with the Northern, and the hemispheric difference shows a strong semidiurnal variation.

  1. Solar activity influences on atmospheric electricity and on some structures in the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Reiter, Reinhold

    1989-01-01

    Only processes in the troposphere and the lower stratosphere are reviewed. General aspects of global atmospheric electricity are summarized in Chapter 3 of NCR (1986); Volland (1984) has outlined the overall problems of atmospheric electrodynamics; and Roble and Hays (1982) published a summary of solar effects on the global circuit. The solar variability and its atmospheric effects (overview by Donelly et al, 1987) and the solar-planetary relationships (survey by James et al. 1983) are so extremely complex that only particular results and selected papers of direct relevance or historical importance are compiled herein.

  2. Investigating possible influence of solar activity on some reported seismic-induced ionospheric precursors via VLF wave propagation in Earth-ionosphere waveguide

    NASA Astrophysics Data System (ADS)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip Kumar; Sasmal, Sudipta; Ray, Suman

    2016-07-01

    The diurnal propagation characteristic of VLF radio signal have been widely used to study pre-seismic ionospheric anomalies, some of which are often reported to be associated with the event. On the other hand, Solar particle events and geomagnetic activity also drive changes in the magnetosphere, which modify ionospheric parameters through the Earth's magnetic field. There are also effects originating from planetary and tidal waves, thermospheric tides and stratospheric warming. Distinguishing or separating seismically induced ionospheric fluctuations from those of other origin remain vital and challenging. In this work, we investigated the influence of solar and geomagnetic origin on some reported 'seismic ionospheric precursors' before a few major earthquakes. We also investigated anomalies in VLF day-length signal during period of low solar and geomagnetic activity (in relation to seismic activity), to understand the occurrence of VLF anomaly that are unrelated to seismicity and solar activity.

  3. Activities for Teaching Solar Energy.

    ERIC Educational Resources Information Center

    Mason, Jack Lee; Cantrell, Joseph S.

    1980-01-01

    Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)

  4. Influence of solar activity on the development of calcareous nannofossils from a Middle Holocene costal paleo-ria (SW Portugal)

    NASA Astrophysics Data System (ADS)

    Hernández, Armand; Cachão, Mário; Trigo, Ricardo M.; Conceição Freitas, M.

    2015-04-01

    periodogram unveils only one significant periodicity (228-yrs). Phases with oceanic influence (downwelling) would be related to 450, 350 and 236-yrs frequencies and the phase with coastal influence (upwelling) would be linked to 228-yrs periodicity. These periodicities fit with previous solar activity reconstructions at millennial-to-centennial scale based on different proxies (Bond et al. 2001, Vaquero et al. 2002, Solanki et al. 2004), which, in turn, are conditioning the earth's climate system. Finally, performed time-frequency analyses on F1 and F2 scores show a higher activity of the 228-yrs periodicity during the whole studied period (spanning between 8.8k and 4.8k cal yr BP) with maximum values between 8k to 7k cal yr BP and 6k to 5k cal yr BP. By contrast, higher periodicities (450, 350 and 236-yrs) would be mainly confined to prior 7.5k cal yrs BP. These results highlight the possibility to use the calcareous nannofossils as indirect proxies of solar activity in cases of ultra-high resolution (centennial) sedimentary sequences. References Alday et al., Estuar Coast Shelf S, 66, 532 (2006). Bond et al., Science, 294, 2130 (2001). Solanki et al., Nature, 431, 1084 (2004). Vaquero et al., Geophys Res Lett, 29, 1997 (2002).

  5. Physics of solar activity

    NASA Technical Reports Server (NTRS)

    Sturrock, Peter A.

    1993-01-01

    The aim of the research activity was to increase our understanding of solar activity through data analysis, theoretical analysis, and computer modeling. Because the research subjects were diverse and many researchers were supported by this grant, a select few key areas of research are described in detail. Areas of research include: (1) energy storage and force-free magnetic field; (2) energy release and particle acceleration; (3) radiation by nonthermal electrons; (4) coronal loops; (5) flare classification; (6) longitude distributions of flares; (7) periodicities detected in the solar activity; (8) coronal heating and related problems; and (9) plasma processes.

  6. Influence of Solar Cycles on Earthquakes

    NASA Astrophysics Data System (ADS)

    Tavares, M.

    2011-12-01

    This research inspects possible influence of solar cycles on earthquakes through of statistical analyses. We also discussed the mechanism that would drive the occurrence of increasing of earthquakes during solar maxima. The study was based on worldwide earthquakes events during approximately four hundred years (1600-2010). The increase of earthquakes events followed the Maxima of Solar cycle, and also depends on the tectonic plate location. From 1600 until 1645 events increased during the Maxima in some of the tectonic plates as Pacific, Arabian and South America. The earthquakes analyzed during two grand solar minima, the Maunder (1645-1720) and the Dalton (1790-1820) showed a decrease in the number of earthquakes and the solar activity. It was observed during these minima a significant number of events at specific geological features. After the last minima (Dalton) the earthquakes pattern increased with solar maxima. The calculations showed that events increasing during solar maxima most in the Pacific, South America or Arabian until 1900. Since there were few records during these three centuries we needed additional analysis on modern data. We took the last four solar cycles events (1950-2010) and made similar calculations. The results agreed with the former calculations. It might be that the mechanism for the Sun-Earth connection relies on the solar wind speed. In both records (1600-1900) and (1950-2010) the results showed a significant increase in earthquakes events in some of the tectonic plates linked to solar maxima. The Solar wind energy striking the Earth's magnetosphere affects the entire environment because the pressure on the region increases and the magnetosphere shrinks sometimes four Earth's radii. This sudden compression causes earthquakes in specific plates. During the times of solar minima the pressure from the solar wind on the earth decreases, then the magnetosphere expands and earthquakes happen in a different pattern according to the

  7. Solar cell activation system

    SciTech Connect

    Apelian, L.

    1983-07-05

    A system for activating solar cells involves the use of phosphorescent paint, the light from which is amplified by a thin magnifying lens and used to activate solar cells. In a typical system, a member painted with phosphorescent paint is mounted adjacent a thin magnifying lens which focuses the light on a predetermined array of sensitive cells such as selenium, cadmium or silicon, mounted on a plastic board. A one-sided mirror is mounted adjacent the cells to reflect the light back onto said cells for purposes of further intensification. The cells may be coupled to rechargeable batteries or used to directly power a small radio or watch.

  8. Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    van Driel-Gesztelyi, Lidia; Schrijver, Carolus J.; Klimchuk, James A.; Charbonneau, Paul; Fletcher, Lyndsay; Hasan, S. Sirajul; Hudson, Hugh S.; Kusano, Kanya; Mandrini, Cristina H.; Peter, Hardi; Vršnak, Bojan; Yan, Yihua

    2012-04-01

    Commission 10 of the International Astronomical Union has more than 650 members who study a wide range of activity phenomena produced by our nearest star, the Sun. Solar activity is intrinsically related to solar magnetic fields and encompasses events from the smallest energy releases (nano- or even picoflares) to the largest eruptions in the Solar System, coronal mass ejections (CMEs), which propagate into the Heliosphere reaching the Earth and beyond. Solar activity is manifested in the appearance of sunspot groups or active regions, which are the principal sources of activity phenomena from the emergence of their magnetic flux through their dispersion and decay. The period 2008-2009 saw an unanticipated extended solar cycle minimum and unprecedentedly weak polar-cap and heliospheric field. Associated with that was the 2009 historical maximum in galactic cosmic rays flux since measurements begun in the middle of the 20th Century. Since then Cycle 24 has re-started solar activity producing some spectacular eruptions observed with a fleet of spacecraft and ground-based facilities. In the last triennium major advances in our knowledge and understanding of solar activity were due to continuing success of space missions as SOHO, Hinode, RHESSI and the twin STEREO spacecraft, further enriched by the breathtaking images of the solar atmosphere produced by the Solar Dynamic Observatory (SDO) launched on 11 February 2010 in the framework of NASA's Living with a Star program. In August 2012, at the time of the IAU General Assembly in Beijing when the mandate of this Commission ends, we will be in the unique position to have for the first time a full 3-D view of the Sun and solar activity phenomena provided by the twin STEREO missions about 120 degrees behind and ahead of Earth and other spacecraft around the Earth and ground-based observatories. These new observational insights are continuously posing new questions, inspiring and advancing theoretical analysis and

  9. Solar Energy Project, Activities: General Solar Topics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of activities which introduce students to concepts and issues relating to solar energy. Lessons frequently presented in the context of solar energy as it relates to contemporary energy problems. Each unit presents an introduction; objectives; necessary skills and knowledge; materials; method;…

  10. Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    Klimchuk, James A.; van Driel-Gesztelyi, Lidia; Schrijver, Carolus J.; Melrose, Donald B.; Fletcher, Lyndsay; Gopalswamy, Natchimuthuk; Harrison, Richard A.; Mandrini, Cristina H.; Peter, Hardi; Tsuneta, Saku; Vršnak, Bojan; Wang, Jing-Xiu

    Commission 10 deals with solar activity in all of its forms, ranging from the smallest nanoflares to the largest coronal mass ejections. This report reviews scientific progress over the roughly two-year period ending in the middle of 2008. This has been an exciting time in solar physics, highlighted by the launches of the Hinode and STEREO missions late in 2006. The report is reasonably comprehensive, though it is far from exhaustive. Limited space prevents the inclusion of many significant results. The report is divided into the following sections: Photosphere and chromosphere; Transition region; Corona and coronal heating; Coronal jets; flares; Coronal mass ejection initiation; Global coronal waves and shocks; Coronal dimming; The link between low coronal CME signatures and magnetic clouds; Coronal mass ejections in the heliosphere; and Coronal mass ejections and space weather. Primary authorship is indicated at the beginning of each section.

  11. Activation of solar flares

    SciTech Connect

    Cargill, P.J.; Migliuolo, S.; Hood, A.W.

    1984-11-01

    The physics of the activation of two-ribbon solar flares via the MHD instability of coronal arcades is presented. The destabilization of a preflare magnetic field is necessary for a rapid energy release, characteristic of the impulsive phase of the flare, to occur. The stability of a number of configurations are examined, and the physical consequences and relative importance of varying pressure profiles and different sets of boundary conditions (involving field-line tying) are discussed. Instability modes, driven unstable by pressure gradients, are candidates for instability. Shearless vs. sheared equilibria are also discussed. (ESA)

  12. Influence of solar activity upon light curves of comets P/Halley (1986 3) and P/Churyumov-Gerasimenko (1982 8)

    NASA Technical Reports Server (NTRS)

    Churyumov, Klim I.; Filonenko, V. S.

    1992-01-01

    It is shown that the comet P/Halley's (1986 3) total magnitudes correlate with changes in the solar activity indices and the solar wind velocity. A statistically reliable correlation between the outbursts of brightness and magnitude variations of the short-period comet Churyumov-Gerasimenko (1982 8) and the level of the solar activity has been discovered.

  13. Moisture variability in the Danube lower basin: an analysis based on the Palmer drought indices and the solar/geomagnetic activity influence

    NASA Astrophysics Data System (ADS)

    Mares, Ileana; Dobrica, Venera; Demetrescu, Crisan; Mares, Constantin

    2014-05-01

    reveal quasi-periodicities of 7-8 years found in the PC1-TPP series also in the Kp. Regarding solar activity, expressed by the Wolf numbers, its influence is significant only for the spring season, highlighted by a cycle of approximate of 11-year in the principal component (PC1) of the drought estimated by temperatures and precipitation (TPP) in Danube lower basin. These preliminary results will be completed with new investigations for the entire Danube basin, considering longer time series and a discriminate analysis by taking into consideration the occurrence of the maxima and minima in the solar/ geomagnetic activity.

  14. Influences of solar wind parameters and geomagnetic activity on the tail lobe magnetic field: A statistical study

    SciTech Connect

    Nakai, H. ); Kamide, Y. ); Russell, C.T. )

    1991-04-01

    The size and magnetic field strength of the tail lobe at the downstream distance of 10 to 22.6 R{sub E} are examined statistically by utilizing data from the magnetometer on board the ISEE 1 satellite. The probability that the satellite encounters the lobe region is mapped on the tail cross sections, the Y-Z plane. It is found that the magnetotail lobe expands in association with increasing auroral electrojet activity. This expansion is particularly evident at the dawn and dusk flanks of the magnetotail, while the lobe region seems not to expand appreciably near the aberrated X axis. The lobe field strength, B{sub L}, is found to be represented as B{sub L}(nT) = 1.03 {times} 10{sup 3} R{sup {minus}1.20}, where R denotes the geocentric distance in Earth radii. Multiple regression analyses reveal that the lobe field strength principally depends on the dynamic pressure (P{sub D}) and static pressure (P{sub S}) of the solar wind as well as on the IMF B{sub Z}. It is also shown that the flaring angle of the tail lobe, {theta}, is represented as sin{sup 2}{theta} = 1.97 {times} 10{sup {minus}5} P{sub D}{sup {minus}0.47}{vert bar} AL {vert bar}{sup 0.11}, where AL denotes the auroral electrojet AL index.

  15. Solar activity secular cycles

    NASA Astrophysics Data System (ADS)

    Kramynin, A. P.; Mordvinov, A. V.

    2013-12-01

    Long-term variations in solar activity secular cycles have been studied using a method for the expansion of reconstructed sunspot number series Sn( t) for 11400 years in terms of natural orthogonal functions. It has been established that three expansion components describe more than 98% of all Sn( t) variations. In this case, the contribution of the first expansion component is about 92%. The averaged form of the 88year secular cycle has been determined based on the form of the first expansion coordinate function. The quasi-periodicities modulating the secular cycle have been revealed based on the time function conjugate to the first function. The quasi-periodicities modulating the secular cycle coincide with those observed in the Sn( t) series spectrum. A change in the secular cycle form and the time variations in this form are described by the second and third expansion components, the contributions of which are about 4 and 2%, respectively. The variations in the steepness of the secular cycle branches are more pronounced in the 200-year cycle, and the secular cycle amplitude varies more evidently in the 2300-year cycle.

  16. Solar activity and the weather

    NASA Technical Reports Server (NTRS)

    Wilcox, J. M.

    1975-01-01

    The attempts during the past century to establish a connection between solar activity and the weather are discussed; some critical remarks about the quality of much of the literature in this field are given. Several recent investigations are summarized. Use of the solar/interplanetary magnetic sector structure in future investigations is suggested to add an element of cohesiveness and interaction to these investigations.

  17. Solar activity and myocardial infarction.

    PubMed

    Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

    1983-01-01

    The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism. PMID:6851574

  18. General overview of the solar activity effects on the lower ionosphere

    NASA Technical Reports Server (NTRS)

    Danilov, A. D.

    1989-01-01

    Solar activity influences the ionospheric D region. That influence manifests itself both in the form of various solar induced disturbances and in the form of the D region dependence on solar activity parameters (UV-flux, interplanetary magnetic field, solar wind etc.) in quiet conditions. Relationship between solar activity and meteorological control of the D region behavior is considered in detail and examples of strong variations of aeronomical parameters due to solar or meteorological events are given.

  19. Solar activity over different timescales

    NASA Astrophysics Data System (ADS)

    Obridko, Vladimir; Nagovitsyn, Yuri

    The report deals with the “General History of the Sun” (multi-scale description of the long-term behavior of solar activity): the possibility of reconstruction. Time scales: • 100-150 years - the Solar Service. • 400 - instrumental observations. • 1000-2000 years - indirect data (polar auroras, sunspots seen with the naked eye). • Over-millennial scale (Holocene) -14С (10Be) Overview and comparison of data sets. General approaches to the problem of reconstruction of solar activity indices on a large timescale. North-South asymmetry of the sunspot formation activity. 200-year cycle over the “evolution timescales”.The relative contribution of the large-scale and low-latitude. components of the solar magnetic field to the general geomagnetic activity. “Large-scale” and low-latitude sources of geomagnetic disturbances.

  20. An influence of solar activity on latitudinal distribution of atmospheric ozone and temperature in 2-D radiative-photochemical model

    NASA Technical Reports Server (NTRS)

    Dyominov, I. G.

    1989-01-01

    On the basis of the 2-D radiative-photochemical model of the ozone layer at heights 0 to 60 km in the Northern Hemisphere there are revealed and analyzed in detail the characteristic features of the season-altitude-latitude variations of ozone and temperature due to changes of the solar flux during the 11 year cycle, electron and proton precipitations.

  1. Deciphering Solar Magnetic Activity: On Grand Minima in Solar Activity

    NASA Astrophysics Data System (ADS)

    Mcintosh, Scott; Leamon, Robert

    2015-07-01

    The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not well understood. There has been tremendous progress in the century since the discovery of solar magnetism - magnetism that ultimately drives the electromagnetic, particulate and eruptive forcing of our planetary system. There is contemporary evidence of a decrease in solar magnetism, perhaps even indicators of a significant downward trend, over recent decades. Are we entering a minimum in solar activity that is deeper and longer than a typical solar minimum, a "grand minimum"? How could we tell if we are? What is a grand minimum and how does the Sun recover? These are very pertinent questions for modern civilization. In this paper we present a hypothetical demonstration of entry and exit from grand minimum conditions based on a recent analysis of solar features over the past 20 years and their possible connection to the origins of the 11(-ish) year solar activity cycle.

  2. Solar collector manufacturing activity, 1988

    NASA Astrophysics Data System (ADS)

    1989-11-01

    This report was prepared by the Energy Information Administration, the independent statistical and analytical agency within the U.S. Department of Energy in cooperation with the Office of Conservation and Renewable Energy. The report presents data on producer shipments and end uses obtained from manufacturers and importers of solar thermal collectors and photovoltaic modules. It provides annual data necessary for the Department of Energy to execute its responsibility to: (1) monitor activities and trends in the solar collector manufacturing industry, (2) prepare the national energy strategy, and (3) provide information on the size and status of the industry to interested groups such as the U.S. Congress, government agencies, the Solar Energy Research institute, solar energy specialists, manufacturers, and the general public.

  3. [Influences of solar and geomagnetic activity on health status of people with various nosological forms of diseases].

    PubMed

    Gadzhiev, G D; Rakhmatulin, R A

    2013-01-01

    Statistical analysis of correlation between heliogeophysical factors and a symptom of the various forms of diseases (based on statistical data on disease of the personnel of Irkutsk Scientific Centre, RAS) has been studied. It is shown that geomagnetic storms influence vegetative regulation of a cardiac rhythm and vascular tone. The most serious consequences of such influence can mainly be observed in the persons suffering from diseases of the cardiovascular system (consequences of myocardium attack, brain strokes, cardiac rhythm disorders); being in a condition of additional stress, mainly with vegetovascular and hypertensic crises; having mental diseases; and subject to aggravations of general diseases (chronic inflammatory diseases of gynecological, musculoskeletal, urinary excretory, bronchopulmonary systems, and systems of digestive organs). PMID:24455893

  4. Solar Energy Project, Activities: Biology.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of biology experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher information…

  5. The magnetic field structure in the active solar corona.

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.

    1971-01-01

    The structure of the magnetic field of the active solar corona is discussed with reference to optical and radio observations of the solar atmosphere. Eclipse observations provide evidence of fine scale structures in the solar atmosphere that appear to relate to the coronal magnetic field. The coronal magnetic field used for comparison is calculated from potential theory; the influence of solar activity upon the potential theory field is discussed with reference to observations of the Faraday rotation of a microwave signal from Pioneer 6 as it was occulted by the solar atmosphere. Evidence has been found suggesting the existence of expanding magnetic bottles located at 10 solar radii above flaring active regions. The dynamics of these events is discussed. It is further suggested that these magnetic bottles are an important component in the solar corona.

  6. Physical mechanisms of solar variability influence on weather and climate

    NASA Astrophysics Data System (ADS)

    Avakyan, Sergei

    2010-05-01

    Numerous researches into correlation of weather and climate characteristics with solar and geomagnetic activity confirm that such correlation does exist. However there is some uncertainty in interpretation of the Sun-weather-climate relations. The paper considers the main causes of this uncertainty which are as follows - the lack of permanent monitoring data on ionizing solar EUV/X-ray radiation including periods of flares; and also the data on electron fluxes of keV energy precipitating from radiation belts first of all during geomagnetic storms; - multiplicity of Sun-weather-climate links; - the lack of understanding what are the mechanisms of solar-geomagnetic activity (flares and storms) influence on weather and climate characteristics; By now mainly the research on galactic cosmic rays (GSR) including Forbush effects and solar cosmic rays (SCR) influences on atmosphere transparence characteristics and further on climate-weather characteristics have been carried out. The GCR flux increase causes the growth of low (usually optically thick) cloudness and therefore produces in generally cooling effect on the mean surface air temperature. The appearance of SCR causes the reduction of stratospheric and tropospheric transparence and produces also usually cooling effect However these events are rare and corresponding variations of fluxes energy are small. At the same time such strong and frequent manifestations of solar activity as flares and magnetic storms are not so far taken into account since it is not known what physical mechanisms could be responsible for energy transfer from solar flares and magnetic storms to the lower atmosphere. The paper describes a novel radio-optical mechanism responsible for the solar-terrestrial links which acts as a three-stage trigger and which could be useful for solving the problem "Sun- weather-climate". This physical mechanism is based on taking into account the excitation of Rydberg states of atoms and molecules in generation of

  7. Distant Futures of Solar Activity

    NASA Astrophysics Data System (ADS)

    Ayres, Thomas

    1997-07-01

    We will explore possible future fates of solar magnetic activity through high-S/N ultraviolet spectra of the ancient Sun analog, Arcturus {K2 III}. The fundamental mechanisms that drive the hot {T>10^6 K} coronae of cool stars remain elusive. Solving the mystery is a central theme of the ``solar-stellar connection;'' whose importance extends beyond astronomy to areas ranging from basic plasma physics to solar-terrestrial relations. A significant property of the activity is that it subsides with age: G dwarfs in young clusters are intense coronal sources, whereas old low mass K giants are so feable in soft X-rays that most are below current detection limits. For that reason, historical studies of activity have been biased towards the younger stars. Now HST/STIS easily can record faint coronal proxies {like Si IV and C IV} in nearby cool subgiants and giants, thereby mitigating the de facto age discrimination. In the solar neighborhood the brightest single star of advanced age {9-11 Gyr} is Alpha Bootis {K2 III}. Previous studies have placed the archetype red giant firmly in the ``coronal graveyard.'' Our project focuses on understanding the ``basal'' chromosphere; molecular cooling catastrophes and the structure of the passive ``COmosphere;'' the dynamics and energy balance of the residual subcoronal gas; and mass loss mechanisms. {This program is a carryover from a failed Cycle 5 GHRS observation.}

  8. Solar ultraviolet-B and photosynthetically active irradiance in the urban sub-canopy: A survey of influences

    NASA Astrophysics Data System (ADS)

    Grant, Richard H.; Heisler, Gordon M.

    1996-12-01

    Stratospheric ozone loss in mid-latitudes is expected to increase the ultraviolet-B (UVB) radiation at the earth's surface. Impacts of this expected increase will depend on many factors, including the distribution of light in other wavelengths. Measurements of the photosynthetically active radiation (PAR) and UVB irradiance were made under clear skies at an open field and under the canopy of scattered trees in a suburban area in W. Lafayette, Indiana, USA (latitude 40.5°). Results showed that when there was significant sky view, the UVB penetration into sub-canopy spaces differs greatly from that of PAR. The UVB T canopy (transmittance; irradiance below canopy/irradiance in open) was inversely related to sky view. The UVB irradiance did not vary as greatly between shaded and sunlit areas as did PAR. Analysis of measurements made near a brick wall indicated that the leaf area of a canopy and the brick wall primarily acted to block fractions of the sky radiance and contributed little scattered UVB to the horizontal plant. A model was developed to predict the UVB and PAR T canopy based on diffuse fraction, sky view, and porosity of the crown(s) through which the beam is penetrating. The model accounted for the UVB and PAR T canopy to within 0.13 and 0.05 root mean squared error (RMSE), respectively. Analysis of the errors due to model assumptions indicated that care must be taken in describing the sky radiance distribution, the porosity of trees, the penetration of diffuse radiation through porous trees, and the location of sky-obstructing trees and buildings.

  9. Solar Influence on Ionosphere and Radio Communications

    NASA Astrophysics Data System (ADS)

    Reddy, B. M.

    2006-11-01

    When we are discussing solar influence on Ionosphere, it will be helpful to remember that less than one-thousandth of the solar energy being intercepted by the planet Earth is responsible for its production and dynamics. This includes the solar wind energy intercepted by a much larger magnetosphere. But it is this small fraction of energy (in the X-rays, EUV and solar wind) that undergoes violent fluctuations during the course of a solar cycle and during such solar events as flares and Coronal Mass Ejections (CMEs).The consequences of these events are now generically dubbed as “Space Weather”. The problems created by extreme space weather events encompass a wide variety of applications of human interest. These include difficulties to satellite operations, ionosphere-reflected H.F Communications, GPS operations and even power grids and gas pipelines. I will restrict my presentation to H.F communications and to certain science elements such as anomalous plasma temperature variations measured by satellites. Particular attention will be given to increases in electron temperatures during magnetic storms in the night time when there is no photo-electron heat input. As this has a bearing on the present theory of electron thermal conduction associated with increase in neutral densities during storms, a detailed analysis will be presented using satellite data. Also the presentation will include examples of H.F communication failures especially at night time, contrary to what is expected at low latitudes. This has serious implications to the communication scenario in India in view of the high Atmospheric Radio Noise at the lower bands of the H.F. Spectrum.

  10. Solar influences on spatial patterns of Eurasian winter temperature and atmospheric general circulation anomalies

    NASA Astrophysics Data System (ADS)

    Chen, Haishan; Ma, Hedi; Li, Xing; Sun, Shanlei

    2015-09-01

    Solar influences on spatial patterns of Eurasian winter climate and possible mechanisms are investigated based on a multiple linear regression method and multisource observational and reanalysis data. Robust and significant solar signals are detected in Eurasian surface air temperature (SAT), and strong solar activity evidently warms most area of the continent. The spatial pattern of sea level pressure (SLP) responses to solar activity is similar but not identical to that of the North Atlantic Oscillation (NAO). Compared to the NAO, geographic distribution of solar-induced SLP anomalies shifts eastward, with significantly enhanced influences over northern Eurasia. Relatively weaker solar signals were also found in mid-to-upper troposphere. The spatial pattern of 500 hPa geopotential anomalies resembles a negative Scandinavia teleconnection pattern, and the 200 hPa subtropical jet is weakened, while zonal wind at high latitudes is enhanced due to strong solar activity. The anomalous zonal circulations can be attributed to the "top-down" mechanism. During high solar activity winters, an enhanced stratospheric zonal wind anomaly propagates downward, causing zonal wind anomalies in the troposphere. However, the "bottom-up" mechanisms may provide more reasonable explanations of the distinct solar influences on Eurasian climate. Solar-induced strong warm advection in lower atmosphere tends to increase SAT but decrease SLP, resulting in enhanced solar influences over northern Eurasia. Meanwhile, change in the land-ocean thermal contrast (LOTC) could also amplify the circulation anomaly. Inhomogeneous surface heating caused by anomalous solar activity modifies LOTC, which probably enhances the solar-induced circulation patterns. Such a positive feedback may potentially strengthen the solar influences.

  11. Statistical evaluation of the significance of the influence of abrupt changes in solar activity on the dynamics of the epidemic process

    NASA Technical Reports Server (NTRS)

    Druzhinin, I. P.; Khamyanova, N. V.; Yagodinskiy, V. N.

    1974-01-01

    Statistical evaluations of the significance of the relationship of abrupt changes in solar activity and discontinuities in the multi-year pattern of an epidemic process are reported. They reliably (with probability of more than 99.9%) show the real nature of this relationship and its great specific weight (about half) in the formation of discontinuities in the multi-year pattern of the processes in question.

  12. Apparent Relations Between Solar Activity and Solar Tides Caused by the Planets

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh

    2007-01-01

    A solar storm is a storm of ions and electrons from the Sun. Large solar storms are usually preceded by solar flares, phenomena that can be characterized quantitatively from Earth. Twenty-five of the thirty-eight largest known solar flares were observed to start when one or more tide-producing planets (Mercury, Venus, Earth, and Jupiter) were either nearly above the event positions (less than 10 deg. longitude) or at the opposing side of the Sun. The probability for this to happen at random is 0.039 percent. This supports the hypothesis that the force or momentum balance (between the solar atmospheric pressure, the gravity field, and magnetic field) on plasma in the looping magnetic field lines in solar corona could be disturbed by tides, resulting in magnetic field reconnection, solar flares, and solar storms. Separately, from the daily position data of Venus, Earth, and Jupiter, an 11-year planet alignment cycle is observed to approximately match the sunspot cycle. This observation supports the hypothesis that the resonance and beat between the solar tide cycle and nontidal solar activity cycle influences the sunspot cycle and its varying magnitudes. The above relations between the unpredictable solar flares and the predictable solar tidal effects could be used and further developed to forecast the dangerous space weather and therefore reduce its destructive power against the humans in space and satellites controlling mobile phones and global positioning satellite (GPS) systems.

  13. Solar activity predicted with artificial intelligence

    NASA Astrophysics Data System (ADS)

    Lundstedt, Henrik

    The variability of solar activity has been described as a non-linear chaotic dynamic system. AI methods are therefore especially suitable for modelling and predicting solar activity. Many indicators of the solar activity have been used, such as sunspot numbers, F 10.7 cm solar radio flux, X-ray flux, and magnetic field data. Artificial neural networks have also been used by many authors to predict solar cycle activity. Such predictions will be discussed. A new attempt to predict the solar activity using SOHO/MDI high-time resolution solar magnetic field data is discussed. The purpose of this new attempt is to be able to predict episodic events and to predict occurrence of coronal mass ejections. These predictions will be a part of the Lund Space Weather Model.

  14. Geomagnetic responses to the solar wind and the solar activity

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1975-01-01

    Following some historical notes, the formation of the magnetosphere and the magnetospheric tail is discussed. The importance of electric fields is stressed and the magnetospheric convection of plasma and magnetic field lines under the influence of large-scale magnetospheric electric fields is outlined. Ionospheric electric fields and currents are intimately related to electric fields and currents in the magnetosphere and the strong coupling between the two regions is discussed. The energy input of the solar wind to the magnetosphere and upper atmosphere is discussed in terms of the reconnection model where interplanetary magnetic field lines merge or connect with the terrestrial field on the sunward side of the magnetosphere. The merged field lines are then stretched behind earth to form the magnetotail so that kinetic energy from the solar wind is converted into magnetic energy in the field lines in the tail. Localized collapses of the crosstail current, which is driven by the large-scale dawn/dusk electric field in the magnetosphere, divert part of this current along geomagnetic field lines to the ionosphere, causing substorms with auroral activity and magnetic disturbances. The collapses also inject plasma into the radiation belts and build up a ring current. Frequent collapses in rapid succession constitute the geomagnetic storm.

  15. Heliobiology, its development, successes and tasks. [solar activity effects on life on earth

    NASA Technical Reports Server (NTRS)

    Platonova, A. T.

    1974-01-01

    Heliobiology studies the influence of changes in solar activity on life. Considered are the influence of periodic solar activity on the development and growth of epidemics, mortality from various diseases, the functional activity of the nervous system, the development of psychic disturbances, the details of the development of microorganisms and many other phenomena in the living world.

  16. Recurrence of solar activity - Evidence for active longitudes

    NASA Technical Reports Server (NTRS)

    Bogart, R. S.

    1982-01-01

    It is pointed out that the autocorrelation coefficients of the daily Wolf sunspot numbers over a period of 128 years reveal a number of interesting features of the variability of solar activity. Besides establishing periodicities for the solar rotation, solar activity cycle, and, perhaps, the 'Gleissberg Cycle', they suggest that active longitudes do exist, but with much greater strength and persistence in some solar cycles than in others. Evidence is adduced for a variation in the solar rotation period, as measured by sunspot number, of as much as two days between different solar cycles.

  17. Sources of the solar wind at solar activity maximum

    NASA Astrophysics Data System (ADS)

    Neugebauer, M.; Liewer, P. C.; Smith, E. J.; Skoug, R. M.; Zurbuchen, T. H.

    2002-12-01

    The photospheric sources of solar wind observed by the Ulysses and ACE spacecraft from 1998 to early 2001 are determined through a two-step mapping process. Solar wind speed measured at the spacecraft is used in a ballistic model to determine a foot point on a source surface at a solar distance of 2.5 solar radii. A potential-field source-surface model is then used to trace the field and flow from the source surface to the photosphere. Comparison of the polarity of the measured interplanetary field with the polarity of the photospheric source region shows good agreement for spacecraft latitudes equatorward of 60°. At higher southern latitudes, the mapping predicts that Ulysses should have observed only outward directed magnetic fields, whereas both polarities were observed. A detailed analysis is performed on four of the solar rotations for which the mapped and observed polarities were in generally good agreement. For those rotations, the solar wind mapped to both coronal holes and active regions. These findings for a period of high solar activity differ from the findings of a similar study of the solar wind in 1994-1995 when solar activity was very low. At solar minimum the fastest wind mapped to the interior of large polar coronal holes while slower wind mapped to the boundaries of those holes or to smaller low-latitude coronal holes. For the data examined in the present study, neither spacecraft detected wind from the small polar coronal holes when they existed and the speed was never as high as that observed by Ulysses at solar minimum. The principal difference between the solar wind from coronal holes and from active regions is that the O7+/O6+ ion ratio is lower for the coronal hole flow, but not as low as in the polar coronal hole flow at solar minimum. Furthermore, the active-region flows appear to be organized into several substreams unlike the more monolithic structure of flows from coronal holes. The boundaries between plasma flows from neighboring

  18. The Solar Dynamics Observatory, Studying the Sun and Its Influence on Other Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Chamberlin, P. C.

    2011-01-01

    The solar photon output, which was once thought to be constant, varies over all time scales from seconds during solar flares to years due to the solar cycle. These solar variations cause significant deviations in the Earth and space environments on similar time scales, such as affecting the atmospheric densities and composition of particular atoms, molecules, and ions in the atmospheres of the Earth and other planets. Presented and discussed will be examples of unprecedented observations from NASA's new solar observatory, the Solar Dynamics Observatory (SDO). Using three specialized instruments, SDO measures the origins of solar activity from inside the Sun, though its atmosphere, then accurately measuring the Sun's radiative output in X-ray and EUV wavelengths (0.1-121 nm). Along with the visually appealing observations will be discussions of what these measurements can tell us about how the plasma motions in all layers of the Sun modifies and strengthens the weak solar dipole magnetic field to drive large energy releases in solar eruptions. Also presented will be examples of how the release of the Sun's energy, in the form of photons and high energy particles, physically influence other bodies in the solar system such as Earth, Mars, and the Moon, and how these changes drive changes in the technology that we are becoming dependent upon. The presentation will continuously emphasize how SDO, the first satellite in NASA's Living with a Star program, improving our understanding of the variable Sun and its Heliospheric influence.

  19. Solar irradiance measurements - Minimum through maximum solar activity

    NASA Technical Reports Server (NTRS)

    Lee, R. B., III; Gibson, M. A.; Shivakumar, N.; Wilson, R.; Kyle, H. L.; Mecherikunnel, A. T.

    1991-01-01

    The Earth Radiation Budget Satellite (ERBS) and the NOAA-9 spacecraft solar monitors were used to measure the total solar irradiance during the period October 1984 to December 1989. Decreasing trends in the irradiance measurements were observed as sunspot activity decreased to minimum levels in 1986; after 1986, increasing trends were observed as sunspot activity increased. The magnitude of the irradiance variability was found to be approximately 0.1 percent between sunspot minimum and maximum (late 1989). When compared with the 1984 to 1989 indices of solar magnetic activity, the irradiance trends appear to be in phase with the 11-year sunspot cycle. Both irradiance series yielded 1,365/sq Wm as the mean value of the solar irradiance, normalized to the mean earth/sun distance. The monitors are electrical substitution, active-cavity radiometers with estimated measurement precisions and accuracies of less than 0.02 and 0.2 percent, respectively.

  20. Modeling of the atmospheric response to a strong decrease of the solar activity

    NASA Astrophysics Data System (ADS)

    Rozanov, Eugene V.; Egorova, Tatiana A.; Shapiro, Alexander I.; Schmutz, Werner K.

    2012-07-01

    We estimate the consequences of a potential strong decrease of the solar activity using the model simulations of the future driven by pure anthropogenic forcing as well as its combination with different solar activity related factors: total solar irradiance, spectral solar irradiance, energetic electron precipitation, solar protons and galactic cosmic rays. The comparison of the model simulations shows that introduced strong decrease of solar activity can lead to some delay of the ozone recovery and partially compensate greenhouse warming acting in the direction opposite to anthropogenic effects. The model results also show that all considered solar forcings are important in different atmospheric layers and geographical regions. However, in the global scale the solar irradiance variability can be considered as the most important solar forcing. The obtained results constitute probably the upper limit of the possible solar influence. Development of the better constrained set of future solar forcings is necessary to address the problem of future climate and ozone layer with more confidence.

  1. Solar activity and oscillation frequency splittings

    NASA Technical Reports Server (NTRS)

    Woodard, M. F.; Libbrecht, K. G.

    1993-01-01

    Solar p-mode frequency splittings, parameterized by the coefficients through order N = 12 of a Legendre polynomial expansion of the mode frequencies as a function of m/L, were obtained from an analysis of helioseismology data taken at Big Bear Solar Observatory during the 4 years 1986 and 1988-1990 (approximately solar minimum to maximum). Inversion of the even-index splitting coefficients confirms that there is a significant contribution to the frequency splittings originating near the solar poles. The strength of the polar contribution is anti correlated with the overall level or solar activity in the active latitudes, suggesting a relation to polar faculae. From an analysis of the odd-index splitting coefficients we infer an uppor limit to changes in the solar equatorial near-surface rotatinal velocity of less than 1.9 m/s (3 sigma limit) between solar minimum and maximum.

  2. How active was solar cycle 22?

    NASA Technical Reports Server (NTRS)

    Hoegy, W. R.; Pesnell, W. D.; Woods, T. N.; Rottman, G. J.

    1993-01-01

    Solar EUV observations from the Langmuir probe on Pioneer Venus Orbiter suggest that at EUV wavelengths solar cycle 22 was more active than solar cycle 21. The Langmuir probe, acting as a photodiode, measured the integrated solar EUV flux over a 13 1/2 year period from January 1979 to June 1992, the longest continuous solar EUV measurement. The Ipe EUV flux correlated very well with the SME measurement of L-alpha during the lifetime of SME and with the UARS SOLSTICE L-alpha from October 1991 to June 1992 when the Ipe measurement ceased. Starting with the peak of solar cycle 21, there was good general agreement of Ipe EUV with the 10.7 cm, Ca K, and He 10830 solar indices, until the onset of solar cycle 22. From 1989 to the start of 1992, the 10.7 cm flux exhibited a broad maximum consisting of two peaks of nearly equal magnitude, whereas Ipe EUV exhibited a strong increase during this time period making the second peak significantly higher than the first. The only solar index that exhibits the same increase in solar activity as Ipe EUV and L-alpha during the cycle 22 peak is the total magnetic flux. The case for high activity during this peak is also supported by the presence of very high solar flare intensity.

  3. Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

  4. Sustainable Buildings. Using Active Solar Power

    SciTech Connect

    Sharp, M. Keith; Barnett, Russell

    2015-04-20

    The objective of this project is to promote awareness and knowledge of active solar energy technologies by installing and monitoring the following demonstration systems in Kentucky: 1) Pool heating system, Churchill Park School, 2) Water heating and daylighting systems, Middletown and Aiken Road Elementary Schools, 3) Photovoltaic street light comparison, Louisville Metro, 4) up to 25 domestic water heating systems across Kentucky. These tasks will be supported by outreach activities, including a solar energy installer training workshop and a Kentucky Solar Energy Conference.

  5. Dynamo theory prediction of solar activity

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth H.

    1988-01-01

    The dynamo theory technique to predict decadal time scale solar activity variations is introduced. The technique was developed following puzzling correlations involved with geomagnetic precursors of solar activity. Based upon this, a dynamo theory method was developed to predict solar activity. The method was used successfully in solar cycle 21 by Schatten, Scherrer, Svalgaard, and Wilcox, after testing with 8 prior solar cycles. Schatten and Sofia used the technique to predict an exceptionally large cycle, peaking early (in 1990) with a sunspot value near 170, likely the second largest on record. Sunspot numbers are increasing, suggesting that: (1) a large cycle is developing, and (2) that the cycle may even surpass the largest cycle (19). A Sporer Butterfly method shows that the cycle can now be expected to peak in the latter half of 1989, consistent with an amplitude comparable to the value predicted near the last solar minimum.

  6. Modified Coronal Index of the Solar Activity

    NASA Astrophysics Data System (ADS)

    Lukáč, B.; Rybanský, M.

    2010-05-01

    The original coronal index of the solar activity (CI) has been constructed on the basis of ground-based measurements of the intensities of the coronal line of 530.3 nm (Rybanský in Bull. Astron. Inst. Czechoslov., 28, 367, 1975; Rybanský et al. in J. Geophys. Res., 110, A08106, 2005). In this paper, CI is compared with the EUV measurements on the CELIAS/SEM equipment based on the same idea as the original idea of the coronal index. The correlation is very good for the period 1996 - 2005 ( r=0.94 for daily values). The principal result of this paper is the introduction of the modified coronal index (MCI) which in all uses and contexts can replace the existing CI index. Daily MCI values extend over a time period of six solar activity cycles. Future MCI measurements will be derived from more reliable measurements made by space-based observatories that are not influenced by the weather. MCI measurements are and will continue to be archived at the web site of the Slovak Central Observatory in Hurbanovo ( http://www.suh.sk/obs/vysl/MCI.htm ).

  7. The Three-Dimenstional Solar Wind at Solar Activity Minimum

    NASA Technical Reports Server (NTRS)

    Neugebauer, M.

    1998-01-01

    In late 1997, the Ulysses spacecraft completed its first orbit around the Sun, observing the properties of the heliosphere at all latitudes between 80 degrees South and 80 degrees North. Because the mission occurred during a period of near-minimum solar activity, the configuration of the solar wind and interplanetary magnetic field were particularly simple, thus allowing confident comparisons between the properties of the polar corona observed by instruments of the Spartan and SOHO spacecraft and the resulting properties of the solar wind.

  8. Solar neutrinos, solar flares, solar activity cycle and the proton decay

    NASA Technical Reports Server (NTRS)

    Raychaudhuri, P.

    1985-01-01

    It is shown that there may be a correlation between the galactic cosmic rays and the solar neutrino data, but it appears that the neutrino flux which may be generated during the large solar cosmic ray events cannot in any way effect the solar neutrino data in Davis experiment. Only initial stage of mixing between the solar core and solar outer layers after the sunspot maximum in the solar activity cycle can explain the higher (run number 27 and 71) of solar neutrino data in Davis experiment. But solar flare induced atmospheric neutrino flux may have effect in the nucleon decay detector on the underground. The neutrino flux from solar cosmic rays may be a useful guide to understand the background of nucleon decay, magnetic monopole search, and the detection of neutrino flux in sea water experiment.

  9. Solar Activity Predictions Based on Solar Dynamo Theories

    NASA Astrophysics Data System (ADS)

    Schatten, Kenneth H.

    2009-05-01

    We review solar activity prediction methods, statistical, precursor, and recently the Dikpati and the Choudhury groups’ use of numerical flux-dynamo methods. Outlining various methods, we compare precursor techniques with weather forecasting. Precursors involve events prior to a solar cycle. First started by the Russian geomagnetician Ohl, and then Brown and Williams; the Earth's field variations near solar minimum was used to predict the next solar cycle, with a correlation of 0.95. From the standpoint of causality, as well as energetically, these relationships were somewhat bizarre. One index used was the "number of anomalous quiet days,” an antiquated, subjective index. Scientific progress cannot be made without some suspension of disbelief; otherwise old paradigms become tautologies. So, with youthful naïveté, Svalgaard, Scherrer, Wilcox and I viewed the results through rose-colored glasses and pressed ahead searching for understanding. We eventually fumbled our way to explaining how the Sun could broadcast the state of its internal dynamo to Earth. We noted one key aspect of the Babcock-Leighton Flux Dynamo theory: the polar field at the end of a cycle serves as a seed for the next cycle's growth. Near solar minimum this field usually bathes the Earth, and thereby affects geomagnetic indices then. We found support by examining 8 previous solar cycles. Using our solar precursor technique we successfully predicted cycles 21, 22 and 23 using WSO and MWSO data. Pesnell and I improved the method using a SODA (SOlar Dynamo Amplitude) Index. In 2005, nearing cycle 23's minimum, Svalgaard and I noted an unusually weak polar field, and forecasted a small cycle 24. We discuss future advances: the flux-dynamo methods. As far as future solar activity, I shall let the Sun decide; it will do so anyhow.

  10. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    ERIC Educational Resources Information Center

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  11. Annual DOE Active Solar Heating and Cooling Contractors Review meeting

    NASA Astrophysics Data System (ADS)

    1981-09-01

    Ninety three project summaries dicussing the following aspects of active solar heating and cooling are presented: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology.

  12. Science Activities in Energy: Solar Energy II.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 14 activities related to solar energy for secondary students. Each activity is outlined on a single card and is introduced by a question such as: (1) how much solar heat comes from the sun? or (2) how many times do you have to run water through a flat-plate collector to get a 10 degree rise in…

  13. Gap between active and passive solar heating

    SciTech Connect

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  14. The risk characteristics of solar and geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Podolska, Katerina

    2016-04-01

    The main aim of this contribution is a deeper analysis of the influence of solar activity which is expected to have an impact on human health, and therefore on mortality, in particular civilization and degenerative diseases. We have constructed the characteristics that represent the risk of solar and geomagnetic activity on human health on the basis of our previous analysis of association between the daily numbers of death on diseases of the nervous system and diseases of the circulatory system and solar and geomagnetic activity in the Czech Republic during the years 1994 - 2013. We used long period daily time series of numbers of deaths by cause, long period time series of solar activity indices (namely R and F10.7), geomagnetic indicies (Kp planetary index, Dst) and ionospheric parameters (foF2 and TEC). The ionospheric parameters were related to the geographic location of the Czech Republic and adjusted for middle geographic latitudes. The risk characteristics were composed by cluster analysis in time series according to the phases of the solar cycle resp. the seasonal insolation at mid-latitudes or the daily period according to the impact of solar and geomagnetic activity on mortality by cause of death from medical cause groups of death VI. Diseases of the nervous system and IX. Diseases of the circulatory system mortality by 10th Revision of International Classification of Diseases WHO (ICD-10).

  15. Solar collector manufacturing activity, 1992

    SciTech Connect

    Not Available

    1993-11-09

    This report presents data provided by US-based manufacturers and importers of solar collectors. Summary data on solar thermal collector shipments are presented for the years 1974 through 1992. Summary data on photovoltaic cell and module shipments are presented for the years 1982 through 1992. Detailed information for solar thermal collectors and photovoltaic cells and modules are presented for 1992. Appendix A describes the survey methodology. Appendix B contains the 1992 survey forms and instructions. Appendices C and D list the companies that responded to the 1992 surveys and granted permission for their names and addresses to appear in the report. Appendix E provides selected tables from this report with data shown in the International System of Units (SI) metric units. Appendix F provides an estimate of installed capacity and energy production from solar collectors for 1992.

  16. Science Activities in Energy: Solar Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 12 activities relating to solar energy. Activities are simple, concrete experiments for fourth, fifth, and sixth grades, which illustrate principles and problems relating to energy. Each activity is outlined on a single card which is introduced by a question. A teacher's supplement…

  17. Solar activities and Climate change hazards

    NASA Astrophysics Data System (ADS)

    Hady, A. A., II

    2014-12-01

    Throughout the geological history of Earth, climate change is one of the recurrent natural hazards. In recent history, the impact of man brought about additional climatic change. Solar activities have had notable effect on palaeoclimatic changes. Contemporary, both solar activities and building-up of green-house gases effect added to the climatic changes. This paper discusses if the global worming caused by the green-house gases effect will be equal or less than the global cooling resulting from the solar activities. In this respect, we refer to the Modern Dalton Minimum (MDM) which stated that starting from year 2005 for the next 40 years; the earth's surface temperature will become cooler than nowadays. However the degree of cooling, previously mentioned in old Dalton Minimum (c. 210 y ago), will be minimized by building-up of green-house gases effect during MDM period. Regarding to the periodicities of solar activities, it is clear that now we have a new solar cycle of around 210 years. Keywords: Solar activities; solar cycles; palaeoclimatic changes; Global cooling; Modern Dalton Minimum.

  18. Sources of solar wind over the solar activity cycle.

    PubMed

    Poletto, Giannina

    2013-05-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review. PMID:25685421

  19. Hinode Captures Images of Solar Active Region

    NASA Video Gallery

    In these images, Hinode's Solar Optical Telescope (SOT) zoomed in on AR 11263 on August 4, 2011, five days before the active region produced the largest flare of this cycle, an X6.9. We show images...

  20. A History of Solar Activity over Millennia

    NASA Astrophysics Data System (ADS)

    Usoskin, Ilya G.

    2013-03-01

    Presented here is a review of present knowledge of the long-term behavior of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the special indices used to quantify different aspects of variable solar activity, with special emphasis upon sunspot number. Over long timescales, quantitative information about past solar activity can only be obtained using a method based upon indirect proxies, such as the cosmogenic isotopes 14C and 10Be in natural stratified archives (e.g., tree rings or ice cores). We give an historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that this method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene. A separate section is devoted to reconstructions of strong solar energetic-particle (SEP) events in the past, that suggest that the present-day average SEP flux is broadly consistent with estimates on longer timescales, and that the occurrence of extra-strong events is unlikely. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.

  1. Low Latitude Aurora: Index of Solar Activity

    NASA Astrophysics Data System (ADS)

    Bekli, M. R.; Aissani, D.; Chadou, I.

    2010-10-01

    Observations of aurora borealis at low latitudes are rare, and are clearly associated with high solar activity. In this paper, we analyze some details of the solar activity during the years 1769-1792. Moreover, we describe in detail three low latitude auroras. The first event was reported by ash-Shalati and observed in North Africa (1770 AD). The second and third events were reported by l'Abbé Mann and observed in Europe (1770 and 1777 AD).

  2. Relationships between solar activity and climate change

    NASA Technical Reports Server (NTRS)

    Roberts, W. O.

    1975-01-01

    The relationship between recurrent droughts in the High Plains of the United States and the double sunspot cycle is discussed in detail. It is suggested that high solar activity is generally related to an increase in meridional circulation and blocking patterns at high and intermediate latitudes, especially in winter, and the effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission.

  3. New NSO Solar Surface Activity Maps

    NASA Astrophysics Data System (ADS)

    Henney, C. J.; Harvey, J. W.

    2001-05-01

    Using NSO-Kitt Peak Vacuum Telescope (KPVT) synoptic data, we present several new solar surface activity maps. The motivation is to test conventional wisdom about conditions that are likely to produce solar activity such as flares, coronal mass ejections and high speed solar wind streams. The ultimate goal is to improve real-time, observation-based models for the purpose of predicting solar activity. A large number of maps will eventually be produced based on the wide range of ideas and models of the conditions thought to lead to solar activity events. When data from the new SOLIS instruments becomes available, the range of possible models that can be tested will be greatly expanded. At present, the daily maps include ones that show magnetic field complexity, emerging flux and high speed solar wind sources. As a proxy for local magnetic potential energy, each element of the magnetic complexity map is the distance-weighted rms of the opposing ambient magnetic field. The flux emergence map is the difference between the two most recent absolute magnetic flux images. The solar wind source map is produced from coronal hole area data. The new maps are available on the NSO-Kitt Peak World Wide Web page. This research was supported in part by the Office of Navel Research Grant N00014-91-J-1040. The NSO-Kitt Peak data used here are produced cooperatively by NSF/AURA, NASA/GSFC, and NOAA/SEC.

  4. Volcanic eruptions and solar activity

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1989-01-01

    The historical record of large volcanic eruptions from 1500 to 1980 is subjected to detailed time series analysis. In two weak but probably statistically significant periodicities of about 11 and 80 yr, the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). Time series analysis of the volcanogenic acidities in a deep ice core from Greenland reveals several very long periods ranging from about 80 to about 350 yr which are similar to the very slow solar cycles previously detected in auroral and C-14 records. Solar flares may cause changes in atmospheric circulation patterns that abruptly alter the earth's spin. The resulting jolt probably triggers small earthquakes which affect volcanism.

  5. 11 -year planetary index of solar activity

    NASA Astrophysics Data System (ADS)

    Okhlopkov, Victor

    In papers [1,2] introduced me parameter - the average difference between the heliocentric longitudes of planets ( ADL ) , which was used for comparison with solar activity. The best connection of solar activity ( Wolf numbers used ) was obtained for the three planets - Venus, Earth and Jupiter. In [1,2] has been allocated envelope curve of the minimum values ADL which has a main periodicity for 22 years and describes well the alternating series of solar activity , which also has a major periodicity of 22. It was shown that the minimum values of the envelope curve extremes ADL planets Venus, Earth and Jupiter are well matched with the 11- year solar activity cycle In these extremes observed linear configuration of the planets Venus, Earth and Jupiter both in their location on one side of the Sun ( conjunctions ) and at the location on the opposite side of the Sun ( three configurations ) This work is a continuation of the above-mentioned , and here for minimum ADL ( planets are in conjunction ) , as well as on the minimum deviation of the planets from a line drawn through them and Sun at the location of the planets on opposite sides of the Sun , compiled index (denoted for brevity as JEV ) that uniquely describes the 11- year solar cycle A comparison of the index JEV with solar activity during the time interval from 1000 to 2013 conducted. For the period from 1000 to 1699 used the Schove series of solar activity and the number of Wolf (1700 - 2013 ) During the time interval from 1000 to 2013 and the main periodicity of the solar activity and the index ADL is 11.07 years. 1. Okhlopkov V.P. Cycles of Solar Activity and the Configurations of Planets // Moscow University Physics Bulletin, 2012 , Vol. 67 , No. 4 , pp. 377-383 http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.3103/S0027134912040108. 2 Okhlopkov VP, Relationship of Solar Activity Cycles to Planetary Configurations // Bulletin of the Russian Academy of Sciences. Physics, 2013 , Vol. 77 , No. 5

  6. Some problems in coupling solar activity to meteorological phenomena

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.

    1974-01-01

    The development of a theory of coupling of solar activity to meteorological phenomena has to date foundered on the two difficulties of (1) devising a mechanism that can modify the behavior of the troposphere while employing only a negligible amount of energy compared with the energy necessary to drive the normal meteorological system; and (2) determining how such a mechanism can effectively couple some relevant magnetospheric process into the troposphere in such a way as to influence the weather. A clue to the nature of the interaction between the weather and solar activity might be provided by the fact that most solar activity undergoes a definite 11-year cycle, while meteorological phenomena undergo either no closely correlated variation, or an 11-year variation, or a 22-year variation.

  7. Some problems in coupling solar activity to meteorological phenomena

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.

    1975-01-01

    The development of a theory of coupling of solar activity to meteorological phenomena is hindered by the difficulties of devising a mechanism that can modify the behavior of the troposphere while employing only a negligible amount of energy compared with the energy necessary to drive the normal meteorological system, and determining how such a mechanism can effectively couple some relevant magnetospheric process into the troposphere in such a way as to influence the weather. A clue to the nature of the interaction between the weather and solar activity might be provided by the fact that most solar activity undergoes a definite 11-yr cycle, and meteorological phenomena undergo either no closely correlated variation, an 11-yr variation, or a 22-yr variation.

  8. Is Solar Activity Once More Fainting?

    NASA Astrophysics Data System (ADS)

    Mares Aguilar, C. E.; Schröder, K.-P.; Song, G.

    2013-04-01

    After an anomalously long and deep minimum, will the Sun now once again reach a period of weaker activity cycles, which would affect northern hemisphere winter climate? We here discuss the current state and outlook of solar activity, and we propose to monitor the solar Ca II K line emission “as a star”, as part of the regular observing schedule of the Hamburg robotic telescope, which is bound to move to Guanajuato this year (2012). In fact, the chromospheric Ca II K line emission is a good proxy for the solar far-ultraviolet flux, as both are generated at about the same plasma temperatures (12-15,000 K) and both originate from the same active regions (plages). The solar ultraviolet flux, in turn, warms the stratosphere by photo dissociation of ozone and other molecules and, consequently, affects the strength of the North Atlantic Oscillation (NOA).

  9. Statistical Properties of Extreme Solar Activity Intervals

    NASA Astrophysics Data System (ADS)

    Lioznova, A. V.; Blinov, A. V.

    2014-01-01

    A study of long-term solar variability reflected in indirect indices of past solar activity leads to stimulating results. We compare the statistics of intervals of very low and very high solar activity derived from two cosmogenic radionuclide records and look for consistency in their timing and physical interpretation. According to the applied criteria, the numbers of minima and of maxima are 61 and 68, respectively, from the 10Be record, and 42 and 46 from the 14C record. The difference between the enhanced and depressed states of solar activity becomes apparent in the difference in their statistical distributions. We find no correlation between the level or type (minimum or maximum) of an extremum and the level or type of the predecessor. The hypothesis of solar activity as a periodic process on the millennial time scale is not supported by the existing proxies. A new homogeneous series of 10Be measurements in polar ice covering the Holocene would be of great value for eliminating the existing discrepancy in the available solar activity reconstructions.

  10. Solar wind influence on Jupiter's magnetosphere and aurora

    NASA Astrophysics Data System (ADS)

    Vogt, Marissa; Gyalay, Szilard; Withers, Paul

    2016-04-01

    Jupiter's magnetosphere is often said to be rotationally driven, with strong centrifugal stresses due to large spatial scales and a rapid planetary rotation period. For example, the main auroral emission at Jupiter is not due to the magnetosphere-solar wind interaction but is driven by a system of corotation enforcement currents that arises to speed up outflowing Iogenic plasma. Additionally, processes like tail reconnection are also thought to be driven, at least in part, by processes internal to the magnetosphere. While the solar wind is generally expected to have only a small influence on Jupiter's magnetosphere and aurora, there is considerable observational evidence that the solar wind does affect the magnetopause standoff distance, auroral radio emissions, and the position and brightness of the UV auroral emissions. We will report on the results of a comprehensive, quantitative study of the influence of the solar wind on various magnetospheric data sets measured by the Galileo mission from 1996 to 2003. Using the Michigan Solar Wind Model (mSWiM) to predict the solar wind conditions upstream of Jupiter, we have identified intervals of high and low solar wind dynamic pressure. We can use this information to quantify how a magnetospheric compression affects the magnetospheric field configuration, which in turn will affect the ionospheric mapping of the main auroral emission. We also consider whether there is evidence that reconnection events occur preferentially during certain solar wind conditions or that the solar wind modulates the quasi-periodicity seen in the magnetic field dipolarizations and flow bursts.

  11. Global water cycle and solar activity variations

    NASA Astrophysics Data System (ADS)

    Al-Tameemi, Muthanna A.; Chukin, Vladimir V.

    2016-05-01

    The water cycle is the most active and most important component in the circulation of global mass and energy in the Earth system. Furthermore, water cycle parameters such as evaporation, precipitation, and precipitable water vapour play a major role in global climate change. In this work, we attempt to determine the impact of solar activity on the global water cycle by analyzing the global monthly values of precipitable water vapour, precipitation, and the Solar Modulation Potential in 1983-2008. The first object of this study was to calculate global evaporation for the period 1983-2008. For this purpose, we determined the water cycle rate from satellite data, and precipitation/evaporation relationship from 10 years of Planet Simulator model data. The second object of our study was to investigate the relationship between the Solar Modulation Potential (solar activity index) and the evaporation for the period 1983-2008. The results showed that there is a relationship between the solar modulation potential and the evaporation values for the period of study. Therefore, we can assume that the solar activity has an impact on the global water cycle.

  12. The solar activity measurements experiments (SAMEX) for improved scientific understanding of solar activity

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The Solar Activity Measurements Experiments (SAMEX) mission is described. It is designed to provide a look at the interactions of magnetic fields and plasmas that create flares and other explosive events on the sun in an effort to understand solar activity and the nature of the solar magnetic field. The need for this mission, the instruments to be used, and the expected benefits of SAMEX are discussed.

  13. Temporal offsets among solar activity indicators

    NASA Astrophysics Data System (ADS)

    Ramesh, K. B.; Vasantharaju, N.

    2014-04-01

    Temporal offsets between the time series of solar activity indicators provide important clues regarding the physical processes responsible for the cyclic variability in the solar atmosphere. Hysteresis patterns generated between any two indicators were popularly used to study their morphological features and further to understand their inter relationships. We use time series of different solar indicators to understand the possible cause-and-effect criteria between their respective source regions. Sensitivity of the upper atmosphere to the activity underneath might play an important role in introducing different evolutionary patterns in the profiles of solar indicators and in turn cause temporal offsets between them. Limitations in the observations may also cause relative shifts in the time series.

  14. Cosmic rays, solar activity, magnetic coupling, and lightning incidence

    NASA Technical Reports Server (NTRS)

    Ely, J. T. A.

    1984-01-01

    A theoretical model is presented and described that unifies the complex influence of several factors on spatial and temporal variation of lightning incidence. These factors include the cosmic radiation, solar activity, and coupling between geomagnetic and interplanetary (solar wind) magnetic fields. Atmospheric electrical conductivity in the 10 km region was shown to be the crucial parameter altered by these factors. The theory reconciles several large scale studies of lightning incidence previously misinterpreted or considered contradictory. The model predicts additional strong effects on variations in lightning incidence, but only small effects on the morphology and rate of thunderstorm development.

  15. Initiation of non-tropical thunderstorms by solar activity

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Goldberg, R. A.

    1976-01-01

    Correlative evidence accumulating since 1926 suggests that there must be some physical coupling mechanism between solar activity and thunderstorm occurrence in middle to high latitudes. Such a link may be provided by alteration of atmospheric electric parameters through the combined influence of high-energy solar protons and decreased cosmic ray intensities, both of which are associated with active solar events. The protons produce excess ionization near and above 20km, while the Forbush decreases a lowered conductivity and enhanced fair-weather atmospheric electric field below that altitude. Consequent effects ultimately lead to a charge distribution similar to that found in thunderclouds, and then other cloud physics processes take over to generate the intense electric fields required for lightning discharge.

  16. Solar activity and Perseid meteor heights

    NASA Astrophysics Data System (ADS)

    Buček, M.; Porubčan, V.; Zigo, P.

    2012-04-01

    Photographic meteor heights of the Perseid meteoroid stream compiled in the IAU Meteor Data Center catalogue observed in 1939-1992, covering five solar activity cycles, are analyzed and their potential variation within a solar activity cycle is investigated and discussed. Of the 673 Perseids selected from the catalogue, the variations of the heights for three independent sets: 524 Perseids with known information on both heights, 397 with known brightness and 279 with the geocentric velocity within a one sigma limit, were investigated. The observed beginning and endpoint heights of the Perseids, normalized for the geocentric velocity and the absolute photographic magnitude correlated with the solar activity represented by the relative sunspot number R, do not exhibit a variation consistent with the solar activity cycle. The result, confirmed also by the correlation analysis, is derived for the mass ranges of larger meteoroids observed by photographic techniques. However, a possible variation of meteor heights controlled by solar activity for smaller meteoroids detected by television and radio techniques remains still open and has to be verified.

  17. Causality principles in solar activity -climate relations.

    NASA Astrophysics Data System (ADS)

    Stauning, Peter

    The relations between solar activity and the terrestrial climate have quite often been inves-tigated. In most cases the analyses have been based on comparisons between time series of solar activity parameters, for instance sunspot numbers, and terrestrial climate parameters, for instance global temperatures. However, many of the reported close relations are based on skilfully manipulated data and neglect of basic causality principles. For cause-effect relations to be reliably established, the variations in the causative function must obviously happen prior to the related effects. Thus it is problematic to use, for instance, running averages of parameters, if the result depends too much on posterior elements of the causative time series or precursory elements of the effects. Even more neglected are the causality principles for cause-effect rela-tions with a strongly varying source function, like for instance the 11 year solar activity cycle. In such cases damping of source variations by smoothing data series, introduces additional im-plied delays, which should be considered in the judgement of apparent correlations between the processed time series of cause and effect parameters. The presentation shall illustrate causal-ity relations between solar activity and terrestrial climate parameters and discuss examples of frequently quoted solar activity-climate relations, which violate basic causality principles.

  18. The Influence of Solar Proton Events in Solar Cycle 23 on the Neutral Middle Atmosphere

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; vonKonig, Miriam; Anderson, John; Roble, Raymond G.; McPeters, Richard D.; Fleming, Eric L.; Russell, James M.

    2004-01-01

    Solar proton events (SPEs) can cause changes in constituents in the Earth's middle atmosphere. The highly energetic protons cause ionizations, excitations, dissociations, and dissociative ionizations of the background constituents, which lead to the production of HO(x) (H, OH, HO2) and NO(y) (N, NO, NO2, NO3, N2O5, HNO3, HO2NO2, ClONO2, BrONO2). The HO(x) increases lead to short-lived ozone decreases in the mesosphere and upper stratosphere due to the short lifetimes of the HO, constituents. The NO(x) increases lead to long-lived stratospheric ozone changes because of the long lifetime of NO(y) constituents in this region. Solar cycle 23 was quite active with SPEs and very large fluxes of high energy protons occurred in July and November 2000, November 200 1, and April 2002. Smaller, but still substantial, proton fluxes impacted the Earth during other months in the 1997-2003 time period. The impact of the very large SPEs on the neutral middle atmosphere during solar cycle 23 will be discussed, including the HO(x), NO(y), ozone variations and induced atmospheric transport changes. Two multi-dimensional models, the Goddard Space Flight Center (GSFC) Two-dimensional (2D) Model and the Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Model (TIME-GCM), were used in computing the influence of the SPEs. The results of the GSFC 2D Model and the TIME-GCM will be shown along with comparisons to the Upper Atmosphere Research Satellite (UARS) Halogen Occultation Experiment (HALOE) and Solar Backscatter Ultraviolet 2 (SBUV/2) instruments.

  19. Global patterns of solar influence on high cloud cover

    NASA Astrophysics Data System (ADS)

    Dima, Mihai; Voiculescu, Mirela

    2016-07-01

    One of the main sources of uncertainty in climate projections is represented by clouds, which have a profound influence on the Earth's radiation budget through the feedbacks in which they are involved. The improvement of clouds representation in General Circulation Models relies largely on constraints derived from observations and on correct identification of processes that influence cloud formation or lifetime. Here we identify solar forced high cloud cover (HCC) patterns in reanalysis and observed data extending over the 1871-2009 period, based on their associations with known fingerprints of the same forcing on surface air temperature, sea surface temperature (SST) and sea level pressure fields. The solar influence on HCC has maximum amplitudes over the Pacific basin, where HCC anomalies are distributed in bands of alternating polarities. The colocation of the HCC and SST anomalies bands indicates a thermal influence on high clouds through convection and an amplification of the HCC anomalies by a positive feedback of long-wave fluxes, which increases the solar signal. Consistent with numerical simulations, the solar forced HCC pattern appears to be generated through a constructive interference between the so-called "top-down" and "bottom-up" mechanisms of solar influence on climate and is amplified by ocean-atmosphere positive feedbacks.

  20. Magnetic Influences on the Solar Wind

    NASA Astrophysics Data System (ADS)

    Woolsey, Lauren

    2016-05-01

    The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still today, the wind acceleration mechanisms and the coronal heating processes remain unsolved challenges in solar physics. In this work, I seek to answer a portion of the mystery by focusing on a particular acceleration process: Alfven waves launched by the motion of magnetic field footpoints in the photosphere. The entire corona is threaded with magnetic loops and flux tubes that open up into the heliosphere. I have sought a better understanding of the role these magnetic fields play in determining solar wind properties in open flux tubes. After an introduction of relevant material, I discuss my parameter study of magnetic field profiles and the statistical understanding we can draw from the resulting steady-state wind. In the chapter following, I describe how I extended this work to consider time dependence in the turbulent heating by Alfven waves in three dimensional simulations. The bursty nature of this heating led to a natural next step that expands my work to include not only the theoretical, but also a project to analyze observations of small network jets in the chromosphere and transition region, and the underlying photospheric magnetic field that forms thresholds in jet production. In summary, this work takes a broad look at the extent to which Alfven-wave-driven turbulent heating can explain measured solar wind properties and other observed phenomena.

  1. Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

    PubMed

    Parisi, A V; Downs, N; Turner, J; Amar, A

    2016-09-01

    A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles. PMID:27450297

  2. Solar Energy Education. Home economics: student activities. Field test edition

    SciTech Connect

    Not Available

    1981-03-01

    A view of solar energy from the standpoint of home economics is taken in this book of activities. Students are provided information on solar energy resources while performing these classroom activities. Instructions for the construction of a solar food dryer and a solar cooker are provided. Topics for study include window treatments, clothing, the history of solar energy, vitamins from the sun, and how to choose the correct solar home. (BCS)

  3. Magnetic Influences on the Solar Wind

    NASA Astrophysics Data System (ADS)

    Woolsey, Lauren N.

    2016-01-01

    The Sun is our closest star, and even with the ability to resolve fine structure, there are several large mysteries that remain unsolved. One of these unanswered questions is how the supersonic outflow from the Sun, the solar wind, is generated and accelerated. In this dissertation, I have investigated the role of Alfvén waves in heating the corona and accelerating the wind. I focus on modeling of flux tubes that are open to the heliosphere, i.e. bundles of magnetic field that stretch beyond a few solar radii into the heliosphere. In these flux tubes, Alfvén waves are launched by the shaking of the footpoints from the convective motions of granulation on the solar photosphere. I present results of modeling efforts in one dimension that investigate how this process changes for a variety of different magnetic field structures over a solar cycle and three-dimensional modeling of time-dependent processes that unlock a connection between pico- and nanoflare-scale events and the turbulent heating generated by counter-propagating Alfvén waves. In addition to computational modeling, I also present efforts to find magnetic thresholds in observations of small-scale network jets seen with the Interface Region Imaging Spectrograph (IRIS). These jets were first discovered by IRIS due to their short lifetimes (10s of seconds) and small size (widths of 100s of kilometers). The findings for this project suggest that the modeled Alfvén-wave-driven turbulence is consistent with these network jets.

  4. Solar activity and the mean global temperature

    NASA Astrophysics Data System (ADS)

    Erlykin, A. D.; Sloan, T.; Wolfendale, A. W.

    2009-01-01

    The variation with time from 1956 to 2002 of the globally averaged rate of ionization produced by cosmic rays in the atmosphere is deduced and shown to have a cyclic component of period roughly twice the 11 year solar cycle period. Long term variations in the global average surface temperature as a function of time since 1956 are found to have a similar cyclic component. The cyclic variations are also observed in the solar irradiance and in the mean daily sun spot number. The cyclic variation in the cosmic ray rate is observed to be delayed by 2-4 years relative to the temperature, the solar irradiance and daily sun spot variations suggesting that the origin of the correlation is more likely to be direct solar activity than cosmic rays. Assuming that the correlation is caused by such solar activity, we deduce that the maximum recent increase in the mean surface temperature of the Earth which can be ascribed to this activity is {\\lesssim }14% of the observed global warming.

  5. The influence of solar spectral variations on global radiative balance

    NASA Astrophysics Data System (ADS)

    Gao, Feng-Ling; Tao, Le-Ren; Cui, Guo-Min; Xu, Jia-Liang; Hua, Tse-Chao

    2015-01-01

    The total solar irradiance (TSI) has been the sole solar input in many climate models for lack of long and reliable time series of solar spectral irradiance (SSI) measurements currently. However, based on the recent SSI measurements by the Solar Radiation and Climate Experiment, which is able to provide full and accurate SSI measurements, the influence of SSI variations on global radiative balance between the descending phase of previous solar cycle in December 2007 and the ascending phase of the current solar cycle in the first half 2010 has been studied in this paper. The results show that the relatively larger TSI in the first half 2010 was mainly due to the ultraviolet and near infrared radiation enhancements, with average increases of 0.11% in 200-400 nm and 0.05% in 760-4000 nm respectively, while the radiation in visible region of 400-760 nm decreased by 0.05%. According to the measurements of ozone from the Aura-Microwave Limb Sounder satellite, the global average stratospheric ozone increased markedly in the layer of 25-40 km at the same time. The visible radiation decrease and stratospheric ozone increase together contributed to the smaller solar radiation at the tropopause for each month of the first half 2010 as compared with that in December 2007, with the maximum decrease of 0.15 W m-2 in March 2010. The study reveals that SSI variations in the ascending solar phase may also cool the Earth-atmosphere system.

  6. The influence of solar wind variability on magnetospheric ULF wave power

    NASA Astrophysics Data System (ADS)

    Pokhotelov, D.; Rae, I. J.; Murphy, K. R.; Mann, I. R.

    2015-06-01

    Magnetospheric ultra-low frequency (ULF) oscillations in the Pc 4-5 frequency range play an important role in the dynamics of Earth's radiation belts, both by enhancing the radial diffusion through incoherent interactions and through the coherent drift-resonant interactions with trapped radiation belt electrons. The statistical distributions of magnetospheric ULF wave power are known to be strongly dependent on solar wind parameters such as solar wind speed and interplanetary magnetic field (IMF) orientation. Statistical characterisation of ULF wave power in the magnetosphere traditionally relies on average solar wind-IMF conditions over a specific time period. In this brief report, we perform an alternative characterisation of the solar wind influence on magnetospheric ULF wave activity through the characterisation of the solar wind driver by its variability using the standard deviation of solar wind parameters rather than a simple time average. We present a statistical study of nearly one solar cycle (1996-2004) of geosynchronous observations of magnetic ULF wave power and find that there is significant variation in ULF wave powers as a function of the dynamic properties of the solar wind. In particular, we find that the variability in IMF vector, rather than variabilities in other parameters (solar wind density, bulk velocity and ion temperature), plays the strongest role in controlling geosynchronous ULF power. We conclude that, although time-averaged bulk properties of the solar wind are a key factor in driving ULF powers in the magnetosphere, the solar wind variability can be an important contributor as well. This highlights the potential importance of including solar wind variability especially in studies of ULF wave dynamics in order to assess the efficiency of solar wind-magnetosphere coupling.

  7. Seismic Holography of Solar Activity

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles

    2000-01-01

    The basic goal of the project was to extend holographic seismic imaging techniques developed under a previous NASA contract, and to incorporate phase diagnostics. Phase-sensitive imaging gives us a powerful probe of local thermal and Doppler perturbations in active region subphotospheres, allowing us to map thermal structure and flows associated with "acoustic moats" and "acoustic glories". These remarkable features were discovered during our work, by applying simple acoustic power holography to active regions. Included in the original project statement was an effort to obtain the first seismic images of active regions on the Sun's far surface.

  8. Influence of a solar eclipse on twilight.

    PubMed

    Geyer, E H; Hoffmann, M; Volland, H

    1994-07-20

    The morning twilight of the presunrise sky was measured at the Hoher-List Observatory during the total eclipse of 22 July 1990. The location of observation was far away from the central eclipse zone. The luminance showed a deep minimum in twilight during the main phase of the solar eclipse compared with normal conditions. A first order scattering model explains the observations reasonably well and shows that the sky radiation during the first phase of twilight at a location far away from the central umbra depends primarily on the height profile of the air pressure between ~ 100 and 200 km. PMID:20935830

  9. Solar activities observed with the New Vacuum Solar Telescope

    NASA Astrophysics Data System (ADS)

    Yang, Shuhong

    2015-08-01

    The New Vacuum Solar Telescope is the most important facility of the Fuxian Solar Observatory in China. Based on the high spatial and temporal resolution NVST observations, we investigate the solar activities in the chromosphere and obtain some new results. (1) Observations of a flux rope tracked by filament activation (Yang et al. 2014a). The filament material is initially located at one end of the flux rope and fills in a section of the rope. Then the filament is activated and the material flows along helical threads, tracking the twisted flux rope structure. The flux rope can be detected in both low temperature and high temperature lines, and there exists a striking anti-correlation between the Hα and EUV lines, which could imply some mild heating of cool filament material to coronal temperatures during the filament activation. (2) Fine structures and overlying loops of homologous confined solar flares (Yang et al. 2014b). At the pre-flare stage, there exists a reconnection between small loops. During the flare processes, the overlying loops, some of which are tracked by activated dark materials, do not break out. These direct observations may illustrate the physical mechanism of confined flares, i.e., magnetic reconnection between the emerging loops and the pre-existing loops triggers flares and the overlying loops prevent the flares from being eruptive. (3) Magnetic reconnection between small-scale loops (Yang et al. 2015). We report the solid observational evidence of magnetic reconnection between two sets of small-scale loops. The observed signatures are consistent with the predictions by reconnection models. The thickness and length of the current sheet are determined to be about 420 km and 1.4 Mm, respectively. The reconnection process contains a slow step and a rapid step. We suggest that the successive slow reconnection changes the conditions around the reconnection site and disrupts the instability, thus leading to the rapid approach of the anti

  10. Solar Energy Project, Activities: Chemistry & Physics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of chemistry and physics experiments. Each unit presents an introduction to the unit; objectives; required skills and knowledge; materials; method; questions; recommendations for further work; and a teacher information sheet.…

  11. Solar Energy Project, Activities: Junior High Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of the junior high science curriculum. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher…

  12. Solar Energy Project, Activities: Earth Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of earth science experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; method; questions; recommendations for further study; and a teacher information sheet. The teacher…

  13. Influence of Diffused Solar Radiation on the Solar Concentrating System of a Plant Shoot Configuration

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya

    Investigation of a plant shoot configuration is used to obtain valuable information concerning the received light system. Additionally, analysis results concerning a plant shoot configuration interaction with direct solar radiation were taken from a past study. However, in order to consider a plant shoot as a received sunlight system, it is necessary to understand the received light characteristics of both direct solar radiation and diffused solar radiation. Under a clear sky, the ratio of direct solar radiation to diffused solar radiation is large. However, under a clouded sky, the amount of diffused solar radiation becomes larger. Therefore, in this paper, we investigate the received light characteristics of a plant shoot configuration under the influence of diffused solar radiation. As a result, we clarify the relationship between the amount of diffused solar radiation and the amount of received light as a function of the characteristics of the plant shoot configuration. In order to obtain diffused solar radiation, it is necessary to correspond to the radiation of the multi-directions. In the analysis, the characteristic of the difference in arrangement of the top leaf and the other leaf was obtained. Therefore, in analysis, leaves other than the top were distributed in the wide range.

  14. 20 March 2015 solar eclipse influence on sporadic E layer

    NASA Astrophysics Data System (ADS)

    Pezzopane, M.; Pietrella, M.; Pignalberi, A.; Tozzi, R.

    2015-11-01

    This paper shows how the solar eclipse occurred on 20 March 2015 influenced the sporadic E (Es) layer as recorded by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. In these locations, the solar eclipse was only partial, with the maximum area of the solar disk obscured by the Moon equal to ∼54% at Rome and ∼45% at Gibilmanna. Nevertheless, it is shown that the strong thermal gradients that usually accompany a solar eclipse, have significantly influenced the Es phenomenology. Specifically, the solar eclipse did not affect the Es layer in terms of its maximum intensity, which is comparable with that of the previous and next day, but rather in terms of its persistence. In fact, both at Rome and Gibilmanna, contrary to what typically happens in March, the Es layer around the solar eclipse time is always present. On the other hand, this persistence is also confirmed by the application of the height-time-intensity (HTI) technique. A detailed analysis of isoheight ionogram plots suggests that traveling ionospheric disturbances (TIDs) likely caused by gravity wave (GW) propagation have played a significant role in causing the persistence of the Es layer.

  15. Vestibular influence on tongue activity.

    PubMed

    Elmund, J; Bowman, J P; Morgan, R J

    1983-07-01

    The vestibular system was electrically stimulated in cats anesthetized with ketamine. Peripheral stimulation by an electrode positioned in the vestibule evoked torsional contralateral eye deviations and an electromyogram (EMG) response in a contralateral dorsal neck extensor. Consistently associated with this well documented vestibular pattern was an EMG response in tongue protrusive muscles, at a latency of 13 +/- 5 (means +/- SD) ms. Stimulation in a specific part of the rostroventral lateral vestibular nucleus elicited the same combination of responses: torsional contralateral eye deviations, dorsal neck EMG, and tongue EMG at a latency of 14 +/- 3 ms. Possible tongue activation by current spread to peripheral and central neural structures was examined in detail. Cerebellar, V, VII, cochlear, IX, X, and XII nerve influences were considered. On the basis of combined evidence, it was concluded that the vestibular system does influence tongue activity. PMID:6602714

  16. Division II: Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    van Driel-Gesztelyi, Lidia; Scrijver, Karel J.; Klimchuk, James A.; Charbonneau, Paul; Fletcher, Lyndsay; Hasan, S. Sirajul; Hudson, Hugh S.; Kusano, Kanya; Mandrini, Cristina H.; Peter, Hardi; Vršnak, Bojan; Yan, Yihua

    2015-08-01

    The Business Meeting of Commission 10 was held as part of the Business Meeting of Division II (Sun and Heliosphere), chaired by Valentin Martínez-Pillet, the President of the Division. The President of Commission 10 (C10; Solar activity), Lidia van Driel-Gesztelyi, took the chair for the business meeting of C10. She summarised the activities of C10 over the triennium and the election of the incoming OC.

  17. Comparison of Solar Active Region Complexity Andgeomagnetic Activity from 1996 TO 2014

    NASA Astrophysics Data System (ADS)

    Tanskanen, E. I.; Nikbakhsh, S.; Perez-Suarez, D.; Hackman, T.

    2015-12-01

    We have studied the influence of magnetic complexity of solar Active Regions (ARs)on geomagnetic activity from 1996 to 2014. Sunspots are visual indicators of ARswhere the solar magnetic field is disturbed. We have used International, American,Space Environment Service Center (SESC) and Space Weather Prediction Center(SWPC) sunspot numbers to examine ARs. Major manifestations of solar magneticactivity, such as flares and Coronal Mass Ejections (CMEs), are associated withARs. For this study we chose the Mount Wilson scheme. It classifies ARs in terms oftheir magnetic topology from the least complex (?) to the most complex one ( ?).Several cases have been found where the more complex structures produce strongerflares and CMEs than the less complex ones. We have a list of identified substormsavailable with different phases and their durations. This will be compared to ourmagnetic complexity data to analyse the effects of active region magnetic complexityto the magnetic activity on the vicinity of the Earth.

  18. Influence of solar UVA on erythemal irradiances.

    PubMed

    Parisi, A V; Turnbull, D J; Kimlin, M G

    2006-06-21

    Many materials in everyday use such as window glass in homes and offices, glass in sunrooms and greenhouses, vehicle glass and some brands of sunscreens act as a barrier to the shorter UVB wavelengths while transmitting some of the longer UVA wavelengths. This paper reports on the erythemal exposures due to the UVA waveband encountered over a 12-month period for a solar zenith angle (SZA) range of 4 degrees to 80 degrees and the resulting times required for an erythemal exposure of one standard erythemal dose (SED) due to the erythemal exposures to the UVA wavelengths. The minimum time for an exposure of one SED due to the UVA wavelengths in winter is approximately double that what it is in summer. The time period of 40 to 60 min was the most frequent length of time for an exposure of one SED with 60 to 80 min the next frequent length of time required for a one SED exposure. PMID:16757874

  19. Continuous plasma outflows from the edge of a solar active region as a possible source of solar wind.

    PubMed

    Sakao, Taro; Kano, Ryouhei; Narukage, Noriyuki; Kotoku, Jun'ichi; Bando, Takamasa; Deluca, Edward E; Lundquist, Loraine L; Tsuneta, Saku; Harra, Louise K; Katsukawa, Yukio; Kubo, Masahito; Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo, Masumi; Bookbinder, Jay A; Golub, Leon; Korreck, Kelly E; Su, Yingna; Shibasaki, Kiyoto; Shimizu, Toshifumi; Nakatani, Ichiro

    2007-12-01

    The Sun continuously expels a huge amount of ionized material into interplanetary space as the solar wind. Despite its influence on the heliospheric environment, the origin of the solar wind has yet to be well identified. In this paper, we report Hinode X-ray Telescope observations of a solar active region. At the edge of the active region, located adjacent to a coronal hole, a pattern of continuous outflow of soft-x-ray-emitting plasmas was identified emanating along apparently open magnetic field lines and into the upper corona. Estimates of temperature and density for the outflowing plasmas suggest a mass loss rate that amounts to approximately 1/4 of the total mass loss rate of the solar wind. These outflows may be indicative of one of the solar wind sources at the Sun. PMID:18063788

  20. Forecasts of solar and geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Joselyn, Joann

    1987-01-01

    Forecasts of solar and geomagnetic activity are critical since these quantities are such important inputs to the thermospheric density models. At this time in the history of solar science there is no way to make such a forecast from first principles. Physical theory applied to the Sun is developing rapidly, but is still primitive. Techniques used for forecasting depend upon the observations over about 130 years, which is only twelve solar cycles. It has been noted that even-numbered cycles systematically tend to be smaller than the odd-numbered ones by about 20 percent. Another observation is that for the last 12 cycle pairs, an even-numbered sunspot cycle looks rather like the next odd-numbered cycle, but with the top cut off. These observations are examples of approximate periodicities that forecasters try to use to achieve some insight into the nature of an upcoming cycle. Another new and useful forecasting aid is a correlation that has been noted between geomagnetic indices and the size of the next solar cycle. Some best estimates are given concerning both activities.

  1. The Heliosphere Through the Solar Activity Cycle

    NASA Technical Reports Server (NTRS)

    Balogh, A.; Lanzerotti, L. J.; Suess, S. T.

    2006-01-01

    Understanding how the Sun changes though its 11-year sunspot cycle and how these changes affect the vast space around the Sun the heliosphere has been one of the principal objectives of space research since the advent of the space age. This book presents the evolution of the heliosphere through an entire solar activity cycle. The last solar cycle (cycle 23) has been the best observed from both the Earth and from a fleet of spacecraft. Of these, the joint ESA-NASA Ulysses probe has provided continuous observations of the state of the heliosphere since 1990 from a unique vantage point, that of a nearly polar orbit around the Sun. Ulysses results affect our understanding of the heliosphere from the interior of the Sun to the interstellar medium - beyond the outer boundary of the heliosphere. Written by scientists closely associated with the Ulysses mission, the book describes and explains the many different aspects of changes in the heliosphere in response to solar activity. In particular, the authors describe the rise in solar ESA and NASA have now unamiously agreed a third extension to operate the highly successful Ulysses spacecraft until March 2008 and, in 2007 and 2008, the European-built space probe will fly over the poles of the Sun for a third time. This will enable Ulysses to add an important chapter to its survey of the high-latitude heliosphere and this additional material would be included in a 2nd edition of this book.

  2. The variations of prominence activities during solar cycle

    NASA Astrophysics Data System (ADS)

    Shimojo, Masumi

    The prominence activities (prominence eruption/disappearance) in the solar atmosphere closely relate with the CMEs that cause great influences on heliosphere and magnetosphere. Gopal-swarmy et al. (2003) reported that 72 The Nobeyama Radioheliograph (NoRH) is observing Sun in microwave (17 GHz) since 1992. At a flare, the main component of the microwave from Sun is emitted from non-thermal electrons that are accelerated by flare. On the other hand, the main component of the microwave is thermal emission when Sun is quiet, and a prominence is clearly observed in microwave because there is the prominence on the limb. We developed the automatic prominence activity detection program based on 17 GHz images observed by NoRH, and investigated the variation of the properties of the prominence activities that oc-curred from 1992 to the end of 2009. We found the following results. 1. The variation in the number of prominence activities is similar to that of sunspots during one solar cycle but there are differences between the peak times of prominence activities and sunspots. 2. The frequency distribution as a function of the magnitude of the prominence activities the size of activated prominences at each phase shows a power-law distribution. The power-law index of the distribution does not change except around the solar minimum. 3. The number of promi-nence activities has a dependence on the latitude On the other hand the average magnitude is independent of the latitude. In the paper, we will also discuss the relationship the other properties of prominence eruptions, solar cycle and the photospheric magnetic field.

  3. Possible helio-geomagnetic activity influence on cardiological cases

    NASA Astrophysics Data System (ADS)

    Katsavrias, Christos

    Eruptive solar events as flares and coronal mass ejections (CMEs) occur during solar activ-ity periods. Energetic particles, fast solar wind plasma and electromagnetic radiation pass through interplanetary space, arrive on Earth's ionosphere-magnetosphere and produce various disturbances. It is well known the negative influence of geomagnetic substorms on the human technological applications on geospace. During the last 25 years, many studies concerning the possible influence on the human health are published. Increase of the Acute Coronary Syn-dromes and disorders of the Cardiac Rhythm, increase of accidents as well as neurological and psychological disorders (e.g. increase of suicides) during or near to the geomagnetic storms time interval are reported. In this study, we research the problem in Greece, focusing on patients with Acute Myocardial Infraction, hospitalized in the 2nd Cardiological Department of the General Hospital of Nikaea (Piraeus City), for the time interval 1997-2007 (23rd solar cycle) and also to the arrival of emergency cardiological cases to Emergency Department of two greek hospitals, the General Hospital of Lamia City and the General Hospital of Veria City during the selected months, with or without helio-geomagnetic activity, of the 23rd solar cycle. Increase of cases is recorded during the periods with increase helio-geomagnetic activity. The necessity of continuing the research for a longer period and with a bigger sample is high; so as to exact more secure conclusions.

  4. Coronal Activity and Extended Solar Cycles

    NASA Astrophysics Data System (ADS)

    Altrock, R. C.

    2012-12-01

    Wilson et al. (1988, Nature 333, 748) discussed a number of solar parameters, which appear at high latitudes and gradually migrate towards the equator, merging with the sunspot "butterfly diagram". They found that this concept had been identified by earlier investigators extending back to 1957. They named this process the "Extended Solar Cycle" (ESC). Altrock (1997, Solar Phys. 170, 411) found that this process continued in Fe XIV 530.3 nm emission features. In cycles 21 - 23 solar maximum occurred when the number of Fe XIV emission regions per day > 0.19 (averaged over 365 days and both hemispheres) first reached latitudes 18°, 21° and 21°, for an average of 20° ± 1.7°. Other recent studies have shown that Torsional Oscillation (TO) negative-shear zones are co-located with the ESC from at least 50° down to the equator and also in the zones where the Rush to the Poles occur. These phenomena indicate that coronal activity occurring up to 50° and higher latitudes is related to TO shear zones, another indicator that the ESC is an important solar process. Another high-latitude process, which appears to be connected with the ESC, is the "Rush to the Poles" ("Rush") of polar crown prominences and their associated coronal emission, including Fe XIV. The Rush is is a harbinger of solar maximum (cf. Altrock, 2003, Solar Phys. 216, 343). Solar maximum in cycles 21 - 23 occurred when the center line of the Rush reached a critical latitude. These latitudes were 76°, 74° and 78°, respectively, for an average of 76° ± 2°. Applying the above conclusions to Cycle 24 is difficult due to the unusual nature of this cycle. Cycle 24 displays an intermittent "Rush" that is only well-defined in the northern hemisphere. In 2009 an initial slope of 4.6°/yr was found in the north, compared to an average of 9.4 ± 1.7 °/yr in the previous three cycles. This early fit to the Rush would have reached 76° at 2014.6. However, in 2010 the slope increased to 7.5°/yr (an increase

  5. Division E Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    Schrijver, Carolus J.; Fletcher, Lyndsay; van Driel-Gesztelyi, Lidia; Asai, Ayumi; Cally, Paul S.; Charbonneau, Paul; Gibson, Sarah E.; Gomez, Daniel; Hasan, Siraj S.; Veronig, Astrid M.; Yan, Yihua

    2016-04-01

    After more than half a century of community support related to the science of ``solar activity'', IAU's Commission 10 was formally discontinued in 2015, to be succeeded by C.E2 with the same area of responsibility. On this occasion, we look back at the growth of the scientific disciplines involved around the world over almost a full century. Solar activity and fields of research looking into the related physics of the heliosphere continue to be vibrant and growing, with currently over 2,000 refereed publications appearing per year from over 4,000 unique authors, publishing in dozens of distinct journals and meeting in dozens of workshops and conferences each year. The size of the rapidly growing community and of the observational and computational data volumes, along with the multitude of connections into other branches of astrophysics, pose significant challenges; aspects of these challenges are beginning to be addressed through, among others, the development of new systems of literature reviews, machine-searchable archives for data and publications, and virtual observatories. As customary in these reports, we highlight some of the research topics that have seen particular interest over the most recent triennium, specifically active-region magnetic fields, coronal thermal structure, coronal seismology, flares and eruptions, and the variability of solar activity on long time scales. We close with a collection of developments, discoveries, and surprises that illustrate the range and dynamics of the discipline.

  6. Quasi-biennial modulation of solar neutrino flux: connections with solar activity

    NASA Astrophysics Data System (ADS)

    Vecchio, A.; Laurenza, M.; D'alessi, L.; Carbone, V.; Storini, M.

    2011-12-01

    A quasi-biennial periodicity has been recently found (Vecchio et al., 2010) in the solar neutrino flux, as detected at the Homestake experiment, as well as in the flux of solar energetic protons, by means of the Empirical Modes Decomposition technique. Moreover, both fluxes have been found to be significantly correlated at the quasi-biennial timescale, thus supporting the hypothesis of a connection between solar neutrinos and solar activity. The origin of this connection is investigated, by modeling how the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect (the process for which the well-known neutrino flavor oscillations are modified in passing through the material) could be influenced by matter fluctuations. As proposed by Burgess et al., 2004, by introducing a background magnetic field in the helioseismic model, density fluctuations can be excited in the radiative zone by the resonance between helioseismic g-modes and Alfvén waves. In particular, with reasonable values of the background magnetic field (10-100 kG), the distance between resonant layers could be of the same order of neutrino oscillation length. We study the effect over this distance of a background magnetic field which is variable with a ~2 yr period, in agreement with typical variations of solar activity. Our findings suggest that the quasi-biennial modulation of the neutrino flux is theoretically possible as a consequence of the magnetic field variations in the solar interior. A. Vecchio, M. Laurenza, V. Carbone, M. Storini, The Astrophysical Journal Letters, 709, L1-L5 (2010). C. Burgess, N. S. Dzhalilov, T. I. Rashba, V., B.Semikoz, J. W. F. Valle, Mon. Not. R. Astron. Soc., 348, 609-624 (2004).

  7. Cosmic rays, solar activity and the climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.; Wolfendale, A. W.

    2013-12-01

    Although it is generally believed that the increase in the mean global surface temperature since industrialization is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this letter a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialization is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century.

  8. Solar activities at Sandia National Laboratories

    SciTech Connect

    Klimas, P.C.; Hasti, D.E.

    1994-03-01

    The use of renewable energy technologies is typically thought of as an integral part of creating and sustaining an environment that maximizes the overall quality of life of the Earth`s present inhabitants and does not leave an undue burden on future generations. Sandia National Laboratories has been a leader in developing and deploying many of these technologies over the last two decades. A common but special aspect of all of these activities is that they are all conducted in cooperation with various types of partners. Some of these partners have an interest in seeing these systems grow in the marketplace, while others are primarily concerned with economic benefits that can come from immediate use of these renewable energy systems. This paper describes solar thermal and photovoltaic technology activities at Sandia that are intended to accelerate the commercialization of these solar systems.

  9. Cosmic Rays, Solar Activity and the Climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.

    2013-02-01

    Although it is generally believed that the increase in the mean global surface temperature since industrialisation is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this paper a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialisation is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century.

  10. Solar activities at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Klimas, Paul C.; Hasti, David E.

    The use of renewable energy technologies is typically thought of as an integral part of creating and sustaining an environment that maximizes the overall quality of life of the Earth's present inhabitants and does not leave an undue burden on future generations. Sandia National Laboratories has been a leader in developing and deploying many of these technologies over the last two decades. A common but special aspect of all of these activities is that they are all conducted in cooperation with various types of partners. Some of these partners have an interest in seeing these systems grow in the marketplace, while others are primarily concerned with economic benefits that can come from immediate use of these renewable energy systems. This paper describes solar thermal and photovoltaic technology activities at Sandia that are intended to accelerate the commercialization of these solar systems.

  11. The Magnetic Origins of Solar Activity

    NASA Technical Reports Server (NTRS)

    Antiochos, S. K.

    2012-01-01

    The defining physical property of the Sun's corona is that the magnetic field dominates the plasma. This property is the genesis for all solar activity ranging from quasi-steady coronal loops to the giant magnetic explosions observed as coronal mass ejections/eruptive flares. The coronal magnetic field is also the fundamental driver of all space weather; consequently, understanding the structure and dynamics of the field, especially its free energy, has long been a central objective in Heliophysics. The main obstacle to achieving this understanding has been the lack of accurate direct measurements of the coronal field. Most attempts to determine the magnetic free energy have relied on extrapolation of photospheric measurements, a notoriously unreliable procedure. In this presentation I will discuss what measurements of the coronal field would be most effective for understanding solar activity. Not surprisingly, the key process for driving solar activity is magnetic reconnection. I will discuss, therefore, how next-generation measurements of the coronal field will allow us to understand not only the origins of space weather, but also one of the most important fundamental processes in cosmic and laboratory plasmas.

  12. Solar irradiance variations due to active regions

    SciTech Connect

    Oster, L.; Schatten, K.H.; Sofia, S.

    1982-05-15

    We have been able to reproduce the variations of the solar irradiance observed by ACRIM to an accuracy of better than +- 0.4 W m/sup -2/, assuming that during the 6 month observation period in 1980 the solar luminosity was constant. The improvement over previous attempts is primarily due to the inclusion of faculae. The reproduction scheme uses simple geometrical data on spot and facula areas, and conventional parameters for the respective fluxes and angular dependencies. The quality of reproduction is not very sensitive to most of the details of these parameters; nevertheless, there conventional parameters cannot be very different from their actual values in the solar atmosphere. It is interesting that the time average of the integrated excess emission (over directions) of the faculae cancels out the integrated deficit produced by the spots, within an accuracy of about 10%. If this behavior were maintained over longer periods of time, say, on the order of an activity cycle, active regions could be viewed as a kind of lighthouse where the energy deficit near the normal direction, associated with the spots, is primarily reemitted close to the tangential directions by the faculae. The currently available data suggest that energy ''storage'' associated with the redirection of flux near active regions on the Sun is comparable to the lifetime of the faculae.

  13. Solar Eruptions Initiated in Sigmoidal Active Regions

    NASA Astrophysics Data System (ADS)

    Savcheva, Antonia

    2016-07-01

    active regions that have been shown to possess high probability for eruption. They present a direct evidence of the existence of flux ropes in the corona prior to the impulsive phase of eruptions. In order to gain insight into their eruptive behavior and how they get destabilized we need to know their 3D magnetic field structure. First, we review some recent observations and modeling of sigmoidal active regions as the primary hosts of solar eruptions, which can also be used as useful laboratories for studying these phenomena. Then, we concentrate on the analysis of observations and highly data-constrained non-linear force-free field (NLFFF) models over the lifetime of several sigmoidal active regions, where we have captured their magnetic field structure around the times of major flares. We present the topology analysis of a couple of sigmoidal regions pointing us to the probable sites of reconnection. A scenario for eruption is put forward by this analysis. We demonstrate the use of this topology analysis to reconcile the observed eruption features with the standard flare model. Finally, we show a glimpse of how such a NLFFF model of an erupting region can be used to initiate a CME in a global MHD code in an unprecedented realistic manner. Such simulations can show the effects of solar transients on the near-Earth environment and solar system space weather.

  14. High Energetic Solar Flares in the Solar Minima Activity in Comparative Study with the Solar Maxima Activity from 1954 to 2014 and Their Effects on the Space Environment

    NASA Astrophysics Data System (ADS)

    Mohamed, Wael

    Solar 11-year cycle of solar activity is characterized by the rise and fall in the numbers and areas of sunspots. On solar maximum activity, many flares and CMEs can affect the near-earth space environment. But on the solar minimum activity, there are sometimes solar proton events, (e.g. High Energetic Solar Proton Flares on the declining phase of solar cycle 22 for M.A.Mosalam Shaltout, 1995), have the same effect for those on the solar maximum activity or more. So, a study must be made for the ascending and descending phases of solar activity for a set of solar cycles (from 1954 to 2014) to confirm the conclusion of Mosalam Shaltout on the light of the present high quality observations from ground and by artificial satellites.

  15. The physical mechanism of the solar variability influence on electrical and climatic characteristics of the troposphere

    NASA Astrophysics Data System (ADS)

    Zherebtsov, G. A.; Kovalenko, V. A.; Molodykh, S. I.

    Possible mechanisms of solar-climatic connections, which may be of importance over short and long time intervals, are discussed. The variations of energetic balance of Earth's climatic system for the last 50 years are estimated. It is ascertained that the imbalance between the flux of solar energy that comes to the Earth and radiates to space is of 0.1% for the last ten years. The significance is analyzed for the possible influence of variations of solar constant upon the energetic balance of the atmosphere. The physical mechanism of the influence of solar activity on climatic characteristics and the atmospheric circulation is suggested and theoretically substantiated. The mechanism is based on the redistribution in lower-troposphere of condensation nuclei by the vertical electric field. This electric field is determined by the ionosphere-Earth electric potential, which in the Polar Regions is controlled not only by tropical thunderstorms and by the galactic cosmic-ray intensity but also by solar cosmic-ray fluxes. The height redistribution in the atmosphere of condensation nuclei with a change of the electric field of the atmosphere is accompanied by a change in total latent heat (phase transition of water vapor), by changes in radiation balance, and by subsequent changes of the thermobaric field of troposphere. The results of analysis of thermobaric field variations for the periods of invasion of abnormally powerful solar cosmic ray fluxes and magnetic storms confirm the reality of manifestation of heliogeophysical disturbances.

  16. The Influence of the Solar Sector Angle on the Ionosphere

    NASA Astrophysics Data System (ADS)

    McWilliams, K. A.; Huyghebaert, D. R.

    2014-12-01

    Undulations of the heliospheric current sheet result in identifiable sectors at Earth where the interplanetary magnetic field (IMF) is directed predominantly toward or away from the Sun. When the IMF is directed toward the Sun magnetic reconnection results in open magnetic field lines in the northern polar cap that are directed upstream into the solar wind, providing a path of direct access for solar wind plasma into the northern polar cap and producing polar rain. At the same time, the reconnected field lines threading the southern polar cap are directed downstream, draping along the magnetotail and leading to low particle fluxes precipitating into the southern polar cap. The magnetic field asymmetry arising from a strong radial IMF component results in asymmetric particle fluxes in the north and south polar caps. At times, a very clear correlation exists between the number of echoes recorded by the Super Dual Auroral Radar Network (SuperDARN) and the orientation of IMF in the solar sector. The polar cap that is connected upstream produces fewer ionospheric and ground echoes for the SuperDARN radars in that hemisphere. The echo occurrence is opposite in the north and in the south, and the high or low echo occurrence persists through the solar sector. The presence or lack of polar rain precipitation is expected to alter the ionospheric density profile and lead to different propagation of the radio waves through the ionosphere. Changes in tropospheric weather circulation have been linked to the passage of a solar sector boundary at Earth, and this direct solar-terrestrial influence at ionospheric altitudes may prove to be essential in understanding interplanetary influences on the troposphere.

  17. Solar Energy Education. Renewable energy activities for earth science

    SciTech Connect

    Not Available

    1980-01-01

    A teaching manual is provided to aid teachers in introducing renewable energy topics to earth science students. The main emphasis is placed on solar energy. Activities for the student include a study of the greenhouse effect, solar gain for home heating, measuring solar radiation, and the construction of a model solar still to obtain fresh water. Instructions for the construction of apparatus to demonstrate a solar still, the greenhouse effect and measurement of the altitude and azimuth of the sun are included. (BCS)

  18. Solar Radiation Influence on Ground-Level Geomagnetic Perturbations

    NASA Astrophysics Data System (ADS)

    Weimer, D. R.; Clauer, C. R.

    2011-12-01

    An empirical model has been developed for predicting ground-level geomagnetic perturbations. Measurements from over 112 magnetometers were used, along with simultaneous observations of the solar wind and interplanetary magnetic field (IMF) from the ACE satellite. These data were from an eight-year period, from 1998 through 2005, covering both the rise and fall of the solar cycle. Variations in the solar radiation during this cycle are incorporated into the model, as determined by the F10.7 index of solar radio flux. Variations in ionospheric conductivity, under the influence of both season (dipole tilt angle) and solar radiation are implicitly included. Comparisons of model calculations with measurements at different locations show very good results. Maps of the magnetic perturbations for different conditions generally look as expected. Surprisingly, increasing the F10.7 index does not always increase the magnetic perturbations on the ground at all locations, as one might expect. The largest increases in the perturbations occur near the cusp when the IMF is Northward or has a strong Y component. However, in the nightside, as well as under the Region-2 currents, the ground-level perturbations are more likely to have a smaller magnitude with a higher F10.7 index.

  19. Tsunami related to solar and geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Cataldi, Gabriele; Cataldi, Daniele; Straser, Valentino

    2016-04-01

    The authors of this study wanted to verify the existence of a correlation between earthquakes of high intensity capable of generating tsunami and variations of solar and Earth's geomagnetic activity. To confirming or not the presence of this kind of correlation, the authors analyzed the conditions of Spaceweather "near Earth" and the characteristics of the Earth's geomagnetic field in the hours that preceded the four earthquakes of high intensity that have generated tsunamis: 1) Japan M9 earthquake occurred on March 11, 2011 at 05:46 UTC; 2) Japan M7.1 earthquake occurred on October 25, 2013 at 17:10 UTC; 3) Chile M8.2 earthquake occurred on April 1, 2014 at 23:46 UTC; 4) Chile M8.3 earthquake occurred on September 16, 2015 at 22:54 UTC. The data relating to the four earthquakes were provided by the United States Geological Survey (USGS). The data on ion density used to realize the correlation study are represented by: solar wind ion density variation detected by ACE (Advanced Composition Explorer) Satellite, in orbit near the L1 Lagrange point, at 1.5 million of km from Earth, in direction of the Sun. The instrument used to perform the measurement of the solar wind ion density is the Electron, Proton, and Alpha Monitor (EPAM) instrument, equipped on the ACE Satellite. To conduct the study, the authors have taken in consideration the variation of the solar wind protons density of three different energy fractions: differential proton flux 1060-1900 keV (p/cm^2-sec-ster-MeV); differential proton flux 761-1220 keV (p/cm^2-sec-ster-MeV); differential proton flux 310-580 keV (p/cm^2-sec-ster-MeV). Geomagnetic activity data were provided by Tromsø Geomagnetic Observatory (TGO), Norway; by Scoresbysund Geomagnetic Observatory (SCO), Greenland, Denmark and by Space Weather Prediction Center of Pushkov Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Troitsk, Moscow Region. The results of the study, in agreement with what already

  20. Preferred longitudes in solar and stellar activity

    NASA Astrophysics Data System (ADS)

    Berdyugina, S. V.

    An analysis of the distribution of starspots on the surfaces of very active stars, such as RS CVn- FK Com-type stars as well as young solar analogs, reveals preferred longitudes of spot formation and their quasi-periodic oscillations, i.e. flip-flop cycles. A non-linear migration of the preferred longitudes suggests the presence of the differential rotation and variations of mean spot latitudes. It enables recovering stellar butterfly diagrams. Such phenomena are found to persist in the sunspot activity as well. A comparison of the observed properties of preferred longitudes on the Sun with those detected on more active stars leads to the conclusion that we can learn fine details of the stellar dynamo by studying the Sun, while its global parameters on the evolutionary time scale are provided by a sample of active stars.

  1. Solar-energy absorber: Active infrared (IR) trap

    NASA Technical Reports Server (NTRS)

    Brantley, L. W., Jr.

    1974-01-01

    Efficiency of solar-energy absorbers may be improved to 95% by actively cooling their intermediate glass plates. This approach may be of interest to manufacturers of solar absorbers and to engineers and scientists developing new sources of energy.

  2. Nanoflare activity in the solar chromosphere

    SciTech Connect

    Jess, D. B.; Mathioudakis, M.; Keys, P. H.

    2014-11-10

    We use ground-based images of high spatial and temporal resolution to search for evidence of nanoflare activity in the solar chromosphere. Through close examination of more than 1 × 10{sup 9} pixels in the immediate vicinity of an active region, we show that the distributions of observed intensity fluctuations have subtle asymmetries. A negative excess in the intensity fluctuations indicates that more pixels have fainter-than-average intensities compared with those that appear brighter than average. By employing Monte Carlo simulations, we reveal how the negative excess can be explained by a series of impulsive events, coupled with exponential decays, that are fractionally below the current resolving limits of low-noise equipment on high-resolution ground-based observatories. Importantly, our Monte Carlo simulations provide clear evidence that the intensity asymmetries cannot be explained by photon-counting statistics alone. A comparison to the coronal work of Terzo et al. suggests that nanoflare activity in the chromosphere is more readily occurring, with an impulsive event occurring every ∼360 s in a 10,000 km{sup 2} area of the chromosphere, some 50 times more events than a comparably sized region of the corona. As a result, nanoflare activity in the chromosphere is likely to play an important role in providing heat energy to this layer of the solar atmosphere.

  3. A Forecast of Reduced Solar Activity and Its Implications for NASA

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth; Franz, Heather

    2005-01-01

    The "Solar Dynamo" method of solar activity forecasting is reviewed. Known generically as a 'precursor" method, insofar as it uses observations which precede solar activity generation, this method now uses the Solar Dynamo Amplitude (SODA) Index to estimate future long-term solar activity. The peak amplitude of the next solar cycle (#24), is estimated at roughly 124 in terms of smoothed F10.7 Radio Flux and 74 in terms of the older, more traditional smoothed international or Zurich Sunspot number (Ri or Rz). These values are significantly smaller than the amplitudes of recent solar cycles. Levels of activity stay large for about four years near the peak in smoothed activity, which is estimated to occur near the 2012 timeflame. Confidence is added to the prediction of low activity by numerous examinations of the Sun s weakened polar field. Direct measurements are obtained by the Mount Wilson Solar Observatory and the Wilcox Solar Observatory. Further support is obtained by examining the Sun s polar faculae (bright features), the shape of coronal soft X-ray "holes," and the shape of the "source surface" - a calculated coronal feature which maps the large scale structure of the Sun s field. These features do not show the characteristics of well-formed polar coronal holes associated with typical solar minima. They show stunted polar field levels, which are thought to result in stunted levels of solar activity during solar cycle #24. The reduced levels of solar activity would have concomitant effects upon the space environment in which satellites orbit. In particular, the largest influences would affect orbit determination of satellites in LEO (Low Earth Orbit), based upon the altered thermospheric and exospheric densities. A decrease in solar activity would result in smaller satellite decay rates, as well as fewer large solar events that can destroy satellite electronic functions. Other effects of reduced solar activity upon the space environment include enhanced

  4. Is motivation influenced by geomagnetic activity?

    PubMed

    Starbuck, S; Cornélissen, G; Halberg, F

    2002-01-01

    To eventually build a scientific bridge to religion by examining whether non-photic, non-thermic solar effects may influence (religious) motivation, invaluable yearly world wide data on activities from 1950 to 1999 by Jehovah's Witnesses on behalf of their church were analyzed chronobiologically. The time structure (chronome) of these archives, insofar as it is able to be evaluated in yearly means for up to half a century, was assessed. Least squares spectra in a frequency range from one cycle in 42 to one in 2.1 years of data on the average number of hours per month spent in work for the church, available from 103 different geographic locations, as well as grand totals also including other sites, revealed a large peak at one cycle in about 21 years. The non-linear least squares fit of a model consisting of a linear trend and a cosine curve with a trial period of 21.0 years, numerically approximating that of the Hale cycle, validated the about 21.0-year component in about 70% of the data series, with the non-overlap of zero by the 95% confidence interval of the amplitude estimate. Estimates of MESOR (midline-estimating statistic of rhythm, a rhythm (or chronome) adjusted mean), amplitude and period were further regressed with geomagnetic latitude. The period estimate did not depend on geomagnetic latitude. The about 21.0-year amplitude tends to be larger at low and middle than at higher latitudes and the resolution of the about 21.0-year cycle, gauged by the width of 95% confidence intervals for the period and amplitude, is higher (the 95% confidence intervals are statistically significantly smaller) at higher than at lower latitudes. Near-matches of periods in solar activity and human motivation hint that the former may influence the latter, while the dependence on latitude constitutes evidence that geomagnetic activity may affect certain brain areas involved in motivation, just as it was earlier found that it is associated with effects on the electrocardiogram

  5. MASC: Magnetic Activity of the Solar Corona

    NASA Astrophysics Data System (ADS)

    Auchere, Frederic; Fineschi, Silvano; Gan, Weiqun; Peter, Hardi; Vial, Jean-Claude; Zhukov, Andrei; Parenti, Susanna; Li, Hui; Romoli, Marco

    We present MASC, an innovative payload designed to explore the magnetic activity of the solar corona. It is composed of three complementary instruments: a Hard-X-ray spectrometer, a UV / EUV imager, and a Visible Light / UV polarimetric coronagraph able to measure the coronal magnetic field. The solar corona is structured in magnetically closed and open structures from which slow and fast solar winds are respectively released. In spite of much progress brought by two decades of almost uninterrupted observations from several space missions, the sources and acceleration mechanisms of both types are still not understood. This continuous expansion of the solar atmosphere is disturbed by sporadic but frequent and violent events. Coronal mass ejections (CMEs) are large-scale massive eruptions of magnetic structures out of the corona, while solar flares trace the sudden heating of coronal plasma and the acceleration of electrons and ions to high, sometimes relativistic, energies. Both phenomena are most probably driven by instabilities of the magnetic field in the corona. The relations between flares and CMEs are still not understood in terms of initiation and energy partition between large-scale motions, small-scale heating and particle acceleration. The initiation is probably related to magnetic reconnection which itself results magnetic topological changes due to e.g. flux emergence, footpoints motions, etc. Acceleration and heating are also strongly coupled since the atmospheric heating is thought to result from the impact of accelerated particles. The measurement of both physical processes and their outputs is consequently of major importance. However, despite its fundamental importance as a driver for the physics of the Sun and of the heliosphere, the magnetic field of our star’s outer atmosphere remains poorly understood. This is due in large part to the fact that the magnetic field is a very difficult quantity to measure. Our knowledge of its strength and

  6. Transient flows of the solar wind associated with small-scale solar activity in solar minimum

    NASA Astrophysics Data System (ADS)

    Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

    The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

  7. Magnetic helicity in emerging solar active regions

    SciTech Connect

    Liu, Y.; Hoeksema, J. T.; Bobra, M.; Hayashi, K.; Sun, X.; Schuck, P. W.

    2014-04-10

    Using vector magnetic field data from the Helioseismic and Magnetic Imager instrument aboard the Solar Dynamics Observatory, we study magnetic helicity injection into the corona in emerging active regions (ARs) and examine the hemispheric helicity rule. In every region studied, photospheric shearing motion contributes most of the helicity accumulated in the corona. In a sample of 28 emerging ARs, 17 follow the hemisphere rule (61% ± 18% at a 95% confidence interval). Magnetic helicity and twist in 25 ARs (89% ± 11%) have the same sign. The maximum magnetic twist, which depends on the size of an AR, is inferred in a sample of 23 emerging ARs with a bipolar magnetic field configuration.

  8. Automatic Tracking of Active Regions and Detection of Solar Flares in Solar EUV Images

    NASA Astrophysics Data System (ADS)

    Caballero, C.; Aranda, M. C.

    2014-05-01

    Solar catalogs are frequently handmade by experts using a manual approach or semi-automated approach. The appearance of new tools is very useful because the work is automated. Nowadays it is impossible to produce solar catalogs using these methods, because of the emergence of new spacecraft that provide a huge amount of information. In this article an automated system for detecting and tracking active regions and solar flares throughout their evolution using the Extreme UV Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO) spacecraft is presented. The system is quite complex and consists of different phases: i) acquisition and preprocessing; ii) segmentation of regions of interest; iii) clustering of these regions to form candidate active regions which can become active regions; iv) tracking of active regions; v) detection of solar flares. This article describes all phases, but focuses on the phases of tracking and detection of active regions and solar flares. The system relies on consecutive solar images using a rotation law to track the active regions. Also, graphs of the evolution of a region and solar evolution are presented to detect solar flares. The procedure developed has been tested on 3500 full-disk solar images (corresponding to 35 days) taken from the spacecraft. More than 75 % of the active regions are tracked and more than 85 % of the solar flares are detected.

  9. The evolution of solar ultraviolet luminosity. [influence on planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.; Walker, J. C. G.

    1982-01-01

    Astronomical observations of stars analogous to the sun are used to construct a tentative account of the evolution of solar UV luminosity. Evidence exists that the young sun was a much more powerful source of energetic particles and radiation than it is today, and while on the main sequence, solar activity has declined as an inverse power law of age as a consequence of angular momentum loss to the solar wind. Observations of pre-main sequence stars indicate that before the sun reached the main sequence, it may have emitted as much as ten thousand times the amount of ultraviolet radiation that it does today. The impact of the results on knowledge of photochemistry and escape of constituents of primordial planetary atmospheres is discussed.

  10. Thermospheric hydrogen - The long-term solar influence

    NASA Technical Reports Server (NTRS)

    Breig, E. L.; Sanatani, S.; Hanson, W. B.

    1985-01-01

    Atmospheric Explorer C and E satellite data are employed for a long-term analysis of the behavior of thermospheric hydrogen with respect to the 11 yr solar cycle. The data covered the period 1974-79 (increasing solar activity) and comprised in situ ionospheric (F region) and neutral atmospheric data. The data were analyzed statistically to characterize low latitude hydrogen behavior, e.g., the diurnal variation and mean concentration over the 5 yr data sampling period. Both the mean and daily maximum/minimum ratio (DMMR) varied with the solar F index. The escaping flux of H ions became a contant around 1000 K. Increasing thermospheric temperatures lowered the DMMR value. However, the DMMR values calculated were consistently large enough to require inclusion of neutral winds and/or diurnal variations in charge exchange fluxes moving in and out of the plasmasphere in any model for thermospheric hydrogen behavior.

  11. Geomagnetic Activity Influence on Thermobaric Characteristics of the Atmosphere.

    NASA Astrophysics Data System (ADS)

    Rubtsova, O. A.; Zherebtsov, G. A.; Kovalenko, V. A.; Molodykh, S. I.

    2009-10-01

    The main points of the model of the solar activity effect on the Earth climatic system are presented. The model is based on the physical mechanism of heliogeophysical factors influence on climatic characteristics and atmospheric circulation in the high-latitude troposphere through the atmospheric electricity. In accordance with this mechanism, the atmospheric electricity parameters in the high latitudes depend on the solar activity; at the same time, they influence the altitude distribution of charged condensation nuclei in the troposphere, as well as the cloudiness formation and radiation balance. The mechanism is proved to operate more efficiently in the high latitudes resulting in additional cloudiness formation in areas with adequate vapour concentration. We present complex analysis results of response of temperature and tropospheric pressure fields to different heliogeophysical disturbances. It is detected that regular changes of the temperature and pressure field dynamic accompany these disturbances.

  12. Radio magnetography of the solar active regions

    NASA Astrophysics Data System (ADS)

    Gelfreikh, G. B.; Shibasaki, K.

    The observations of the solar magnetic fields is one of the most important basics for study of all important processes in structuring the solar atmosphere and most kinds of the release of the energy. The radio methods are of the special interest here because they gain the information on the magnetic field strength in the solar corona and upper chromosphere where traditional optical methods do not work. The construction of the Nobeyama radio heliograph opens a new era in usage radio methods for solar radio magnetography due to some unique property of the instrument: - The 2D mapping of the whole disk of the sun both in I and V Stokes parameters with resolution of 10 arcsec. - Regular observations (without breaks due to weather conditions), eight hours a day, already for seven years. The most effective and representative radio method of measuring the solar magnetic fields is to use polarization measurements of the thermal bremsstrahlung (free-free emission). It is applicable both to analysis of chromospheric and coronal magnetic fields and presents information on longitude component of the magnetic field strength in solar active regions. Three problems are met, however: (i) One needs to measure very low degree of polarization (small fraction of a percent); (ii) To get the real value of the field the spectral data are necessary. (iii) While observing an active region on the disk we have got the overlapping effects on polarized signal of the chromospheric and coronal magnetic fields. To get higher sensitivity the averaging of the radio maps over periods of about ten minutes were used with the results of sensitivity on V-maps of the order 0.1%. Observations for a number of dates have been analysed (August 22, 1992, October 31, 1992; June 30, 1993, July 22,1994, June 15, 1995 and some more). In all cases a very good similarity was found of the polarized regions (V-maps) with the Ca^ + plages in form and total coincidence with the direction of the magnetic fields on the

  13. Influence of solar wind ions on photoemission charging of dust

    NASA Astrophysics Data System (ADS)

    Nouzak, Libor; Richterova, Ivana; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek

    2016-04-01

    The lunar surface covered by a layer of dust grains is exposed to solar wind particles and photons coming from the Sun on the sunlit side. Solar wind ions cause sputtering of dust grains or can be implanted into grains. We suppose that as a consequence of ion implantation, an additional energy is transferred to grains, more valence band electrons are excited, and the photoelectron yield is increased. An increase of the photoelectron current causes the enhanced density of electrons that form a sheet above the illuminated lunar surface. Thus, an influence of solar wind ions on the Debye length and photoelectron sheet formation is expected. We present laboratory estimations of work functions and photoelectron yields of a single micron-sized silica grain before and after ion implantation. The silica grain used as a lunar simulant is caught in the electrodynamic trap. Grain's specific charge is evaluated by an analysis of the grain motion within the trap, while its work function is determined from observations of a time evolution of the charge-to-mass ratio when the grain is irradiated by photons of different emission lines. By comparison of the photoelectron current (from grain) with photon flux (from UV source), we establish the photoelectron yield of the trapped object. The influence of ion implantation is thoroughly analyzed and discussed.

  14. Composite Mg II solar activity index for solar cycles 21 and 22

    NASA Technical Reports Server (NTRS)

    Deland, Matthew T.; Cebula, Richard P.

    1993-01-01

    On the basis of version 1.0 of the composite MG II solar activity index data set, it is shown that the change in the 27-day running average of the Mg II index from solar maximum to solar minimum is about 8 percent for solar cycle 21 and about 9 percent for solar cycle 22 through January 1992. Scaling factors based on the short-term variations in the Mg II index and solar irradiance data sets are developed for each instrument to estimate solar variability at mid-UV and near-UV wavelengths. A set of composite scale factors are derived for use with the present composite MG index. Near 205 cm, where solar irradiance variations are important for stratospheric chemistry, the estimated change in irradiance during solar cycle 22 is about 10 +/- 1 percent using the composite Mg II index (version 1.0) and scale factors.

  15. Correlation of Doppler noise during solar conjunctions with fluctuations in solar activity

    NASA Technical Reports Server (NTRS)

    Berman, A. L.; Rockwell, S. T.

    1975-01-01

    Deviations betweeb observed Doppler noise and the noise model during solar conjunction were analyzed. It is tentatively concluded that these deviations are due to short-term fluctuations in solar activity as seen along the signal path, and not to solar/antenna structure effects or system noise temperature.

  16. Long-term persistence of solar activity

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.

  17. The Long-term Middle Atmospheric Influence of Very Large Solar Proton Events

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Randall, Cora E.; Fleming, Eric L.; Frith, Stacey M.

    2008-01-01

    Long-term variations in ozone have been caused by both natural and humankind related processes. The humankind or anthropogenic influence on ozone originates from the chlorofluorocarbons and halons (chlorine and bromine) and has led to international regulations greatly limiting the release of these substances. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the long-term (> few months) influences of solar proton events from 1963 through 2004 on stratospheric ozone and temperature. There were extremely large solar proton events in 1972, 1989,2000,2001, and 2003. These events caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen-containing compounds, which led to the polar ozone destruction. The nitrogen-containing compounds, called odd nitrogen, lasted much longer than the hydrogen-containing compounds and led to long-lived stratospheric impacts. An extremely active period for these events occurred in the five-year period, 2000- 2004, and caused increases in odd nitrogen which lasted for several months after individual events. Associated stratospheric ozone decreases of >lo% were calculated

  18. Geoeffective and Climate-Influencing Solar and Interplanetary Conditions

    NASA Astrophysics Data System (ADS)

    Baranyi, T.; Ludmány, A.

    Several connections have been detected and demonstrated between solar magnetic conditions and climatic responses which hint at a highly complicated mechanism of sun-climate relations through plasma streams. The present contribution overviews our results about the possible factors of this mechanism. The main factor is the negative value of the interplanetary magnetic B_z component which exhibits a fairly complex behaviour. Its strength is influenced by the solar dipole cycle, the nature of ejected plasma (CME or fast stream), the magnetic topology of the CME and the position of the Earth (Rosenberg-Coleman and Russell-McPherron effects). The persistence of the negative B_z is also effective. The impacts of these features can be pointed out in the climatic responses.

  19. Solar Energy Education. Industrial arts: student activities. Field test edition

    SciTech Connect

    Not Available

    1981-02-01

    In this teaching manual several activities are presented to introduce students to information on solar energy through classroom instruction. Wind power is also included. Instructions for constructing demonstration models for passive solar systems, photovoltaic cells, solar collectors and water heaters, and a bicycle wheel wind turbine are provided. (BCS)

  20. Solar Influence on Medieval Megadroughts in the Greater Near East

    NASA Astrophysics Data System (ADS)

    Kushnir, Y.; Stein, M.

    2014-12-01

    Recent surveys of medieval era chronicles provide calendar accurate information of years of unusual, extreme weather and climate events in areas surrounding the eastern Mediterranean, between the mid-A.D. 10th century and end of the 11th century. Put together, these documents show that the region was simultaneously afflicted by unprecedented sever and persistent droughts in Egypt's Nile Valley and by unusually cold and dry winters associated with crop failure and loss of pasture areas in present-day Iraq and Iran, and in historical Khurasan. We show that this documentary information is consistent with the annually dated Nile summer flood record as measured at the Cairo Nilometer site and within acceptable dating accuracies with much more coarsely resolved regional paleoclimate proxies. We furthermore note that the timing of these events coincided with the Oort Grand Solar Minimum that reached its peak between A.D. 1040 and 1080. Given the scientific evidence for the impact of solar minima on sea surface temperatures in the equatorial Pacific and how the latter affect the intensity of the African summer monsoon, we argue that the Oort Solar Minimum forced the frequent failure of the Nile summer floods resulting in dearth and famine in Egypt. Furthermore, the simultaneous cold and dry winters in the northern Near East are also consistent with the hypothesized solar minimum influence on the North Atlantic Oscillation and on the intensity of the Siberian High. This interpretation underscores the sensitivity of the climate system to variations in solar irradiance, particularly on multi-decadal time scales, to their role in regional processes, and their impact on human history and may help understand other rapid Mediterranean cooling events that occured during the Holocene.

  1. Solar-terrestrial predictions proceedings. Volume 4: Prediction of terrestrial effects of solar activity

    NASA Technical Reports Server (NTRS)

    Donnelly, R. E. (Editor)

    1980-01-01

    Papers about prediction of ionospheric and radio propagation conditions based primarily on empirical or statistical relations is discussed. Predictions of sporadic E, spread F, and scintillations generally involve statistical or empirical predictions. The correlation between solar-activity and terrestrial seismic activity and the possible relation between solar activity and biological effects is discussed.

  2. TEC variability over Havana for different solar activity conditions

    NASA Astrophysics Data System (ADS)

    Lazo, B.; Alazo, K.; Rodríguez, M.; Calzadilla, A.

    2004-01-01

    The variability of total electron content measured over Havana using ATS-6, SMS-1 and GOES-3 geosynchronous satellite signals has been investigated for low, middle and high solar activity periods from 1974 to 1982. The results show that the standard deviation is smooth during the nighttime hours and maximal at the noon or postnoon hours. A strong solar activity dependence of the standard deviation has been found with maximum values during periods of high solar activity.

  3. Solar wind turbulence as a driver of geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Ikechukwu Ugwu, Ernest Benjamin; Nneka Okeke, Francisca; Ugonabo, Obiageli Josephine

    2016-07-01

    We carried out simultaneous analyses of interplanetary and geomagnetic datasets for the period of (solar Maunder) least (2009) and maximum (2002) solar activity to determine the nature of solar wind turbulence on geomagnetic activity using AE, ASY-D, and ASY-H indices. We determined the role played by Alfvénic fluctuations in the solar wind so as to find out the nature of the turbulence. Our analyses showed that solar wind turbulence play a role in geomagnetic processes at high latitudes during periods of low and high solaractivity but does not have any effect at mid-low latitudes.

  4. The influence of solar variability past, present and future, on North Atlantic climate.

    NASA Astrophysics Data System (ADS)

    Dunstone, Nick; Scaife, Adam; Ineson, Sarah; Gray, Lesley; Knight, Jeff; Lockwood, Mike; Maycock, Amanda

    2014-05-01

    There has long existed observational evidence for a link between solar activity (both the semi-regular 11-yr cycle and longer term variability) and regional climate variability. In the last few years progress is starting to be made in understanding such observational correlations from physical mechanistic viewpoint. Firstly, new observations of solar spectral irradiance from the SORCE satellite have raised the possibility of much larger variability in the UV than previously appreciated. Secondly, state of the art computer climate models now explicitly resolve the Earth's stratosphere allowing the influence of solar variability to be simulated here. By driving such climate models with the larger solar UV variability implied by the latest satellite observations, surface climate impacts have been shown in the Northern Hemisphere winter that are consistent with late 20th century climate data. Low solar activity is associated with the negative phase of the North Atlantic Oscillation (NAO) and hence colder winters over northern Europe and the USA. We discuss the implications for seasonal/decadal climate prediction. Further work has examined the role of ocean feedbacks in amplifying this tropospheric response. There is robust statistical evidence that such a feedback operates in the observations and gives a lag of 3-4 years for the maximum tropospheric response after the maximum solar forcing. This lag does not generally appear to be reproduced by current climate models. We discuss how this observational evidence may be a valuable way of assessing the relative strength of ocean-atmosphere coupling in the present generation of climate models. The prolonged solar minimum during the transition between solar cycles 23 & 24, combined with the relatively low maximum activity of cycle 24, have increased suggestions that we may be coming to the end of the grand solar maximum which dominated the 20th century. A return to Maunder Minimum like solar activity is therefore a possible

  5. Prominences: The Key to Understanding Solar Activity

    NASA Technical Reports Server (NTRS)

    Karpen, Judy T.

    2011-01-01

    Prominences are spectacular manifestations of both quiescent and eruptive solar activity. The largest examples can be seen with the naked eye during eclipses, making prominences among the first solar features to be described and catalogued. Steady improvements in temporal and spatial resolution from both ground- and space-based instruments have led us to recognize how complex and dynamic these majestic structures really are. Their distinguishing characteristics - cool knots and threads suspended in the hot corona, alignment along inversion lines in the photospheric magnetic field within highly sheared filament channels, and a tendency to disappear through eruption - offer vital clues as to their origin and dynamic evolution. Interpreting these clues has proven to be contentious, however, leading to fundamentally different models that address the basic questions: What is the magnetic structure supporting prominences, and how does so much cool, dense plasma appear in the corona? Despite centuries of increasingly detailed observations, the magnetic and plasma structures in prominences are poorly known. Routine measurements of the vector magnetic field in and around prominences have become possible only recently, while long-term monitoring of the underlying filament-channel formation process also remains scarce. The process responsible for prominence mass is equally difficult to establish, although we have long known that the chromosphere is the only plausible source. As I will discuss, however, the motions and locations of prominence material can be used to trace the coronal field, thus defining the magnetic origins of solar eruptions. A combination of observations, theory, and numerical modeling must be used to determine whether any of the competing theories accurately represents the physics of prominences. I will discuss the criteria for a successful prominence model, compare the leading models, and present in detail one promising, comprehensive scenario for

  6. Evidence for a Solar Influence on Gamma Radiation from Radon

    NASA Astrophysics Data System (ADS)

    Sturrock, P. A.; Steinitz, G.; Fischbach, E.; Javorsek, D.; Jenkins, J.

    2012-12-01

    We have analyzed 29,000 measurements of gamma radiation associated with the decay of radon confined to an airtight vessel at the Geological Survey of Israel (GSI) Laboratory in Jerusalem between January 28 2007 and May 10 2010. These measurements exhibit strong variations in time of year and time of day, which may be due in part to environmental influences. However, time-series analysis reveals a number of strong periodicities, including two at approximately 11.2 year-1 and 12.5 year-1. We consider it significant that these same oscillations have previously been detected in nuclear-decay data acquired at the Brookhaven National Laboratory and at the Physiklisch-Technische Bundesanstalt. We have suggested that these oscillations are due to some form of solar radiation (possibly neutrinos) that has its origin in the deep solar interior. A curious property of the GSI data is that the annual oscillation is much stronger in daytime data than in nighttime data, but the opposite is true for all other oscillations. Time-frequency analysis also yields quite different results from daytime and nighttime data. These procedures have also been applied to data collected from subsurface geological sites in Israel, Tenerife, and Italy, which have a variety of geological and geophysical scenarios, different elevations, and depths below the surface ranging from several meters to 1000 meters. In view of these results, and in view of the fact that there is at present no clear understanding of the behavior of radon in its natural environment, there would appear to be a need for multi-disciplinary research. Investigations that clarify the nature and mechanisms of solar influences may help clarify the nature and mechanisms of geological influences.

  7. Solar activity at birth predicted infant survival and women's fertility in historical Norway

    PubMed Central

    Skjærvø, Gine Roll; Fossøy, Frode; Røskaft, Eivin

    2015-01-01

    Ultraviolet radiation (UVR) can suppress essential molecular and cellular mechanisms during early development in living organisms and variations in solar activity during early development may thus influence their health and reproduction. Although the ultimate consequences of UVR on aquatic organisms in early life are well known, similar studies on terrestrial vertebrates, including humans, have remained limited. Using data on temporal variation in sunspot numbers and individual-based demographic data (N = 8662 births) from Norway between 1676 and 1878, while controlling for maternal effects, socioeconomic status, cohort and ecology, we show that solar activity (total solar irradiance) at birth decreased the probability of survival to adulthood for both men and women. On average, the lifespans of individuals born in a solar maximum period were 5.2 years shorter than those born in a solar minimum period. In addition, fertility and lifetime reproductive success (LRS) were reduced among low-status women born in years with high solar activity. The proximate explanation for the relationship between solar activity and infant mortality may be an effect of folate degradation during pregnancy caused by UVR. Our results suggest that solar activity at birth may have consequences for human lifetime performance both within and between generations. PMID:25567646

  8. Solar activity at birth predicted infant survival and women's fertility in historical Norway.

    PubMed

    Skjærvø, Gine Roll; Fossøy, Frode; Røskaft, Eivin

    2015-02-22

    Ultraviolet radiation (UVR) can suppress essential molecular and cellular mechanisms during early development in living organisms and variations in solar activity during early development may thus influence their health and reproduction. Although the ultimate consequences of UVR on aquatic organisms in early life are well known, similar studies on terrestrial vertebrates, including humans, have remained limited. Using data on temporal variation in sunspot numbers and individual-based demographic data (N = 8662 births) from Norway between 1676 and 1878, while controlling for maternal effects, socioeconomic status, cohort and ecology, we show that solar activity (total solar irradiance) at birth decreased the probability of survival to adulthood for both men and women. On average, the lifespans of individuals born in a solar maximum period were 5.2 years shorter than those born in a solar minimum period. In addition, fertility and lifetime reproductive success (LRS) were reduced among low-status women born in years with high solar activity. The proximate explanation for the relationship between solar activity and infant mortality may be an effect of folate degradation during pregnancy caused by UVR. Our results suggest that solar activity at birth may have consequences for human lifetime performance both within and between generations. PMID:25567646

  9. Change of solar cell element properties influenced by adsorbed atoms

    NASA Astrophysics Data System (ADS)

    Livshits, A. I.; Romanovskij, Y. A.; Zavilopulo, A. N.; Zhukov, A. I.; Snegurskij, A. V.

    A series of experimental studies on the influence of alkali and alkaline-earth metal films on electro-physical properties of solar elements used for spacecraft energy supply was carried out. Metal films of different thicknesses were deposited using an effusion source, the mass of the film was calculated using measured atomic beam density. The Mg film thickness was determined by means of microscopic technique. The dynamics of current-to-voltage characteristic variation was studied for different film thickness and chemical composition in vacuum and in oxygen atmosphere.

  10. 9,400 years of cosmic radiation and solar activity from ice cores and tree rings

    PubMed Central

    Steinhilber, Friedhelm; Beer, Jürg; Brunner, Irene; Christl, Marcus; Fischer, Hubertus; Heikkilä, Ulla; Kubik, Peter W.; Mann, Mathias; McCracken, Ken G.; Miller, Heinrich; Miyahara, Hiroko; Oerter, Hans

    2012-01-01

    Understanding the temporal variation of cosmic radiation and solar activity during the Holocene is essential for studies of the solar-terrestrial relationship. Cosmic-ray produced radionuclides, such as 10Be and 14C which are stored in polar ice cores and tree rings, offer the unique opportunity to reconstruct the history of cosmic radiation and solar activity over many millennia. Although records from different archives basically agree, they also show some deviations during certain periods. So far most reconstructions were based on only one single radionuclide record, which makes detection and correction of these deviations impossible. Here we combine different 10Be ice core records from Greenland and Antarctica with the global 14C tree ring record using principal component analysis. This approach is only possible due to a new high-resolution 10Be record from Dronning Maud Land obtained within the European Project for Ice Coring in Antarctica in Antarctica. The new cosmic radiation record enables us to derive total solar irradiance, which is then used as a proxy of solar activity to identify the solar imprint in an Asian climate record. Though generally the agreement between solar forcing and Asian climate is good, there are also periods without any coherence, pointing to other forcings like volcanoes and greenhouse gases and their corresponding feedbacks. The newly derived records have the potential to improve our understanding of the solar dynamics and to quantify the solar influence on climate. PMID:22474348

  11. Diagnostics of a cause-effect relation between solar activity and the Earth's global surface temperature

    NASA Astrophysics Data System (ADS)

    Mokhov, I. I.; Smirnov, D. A.

    2008-06-01

    The influence of solar activity on the Earth’s global surface temperature (GST) was quantified. The method for estimation of the Granger causality was used, with analysis of the improvement of the prediction of one process by using data from another process as compared to autoprediction. Two versions of reconstructions of the solar flux variations associated with solar activity were used, according to Hoyt et al. [1997] for 1680 1992 (data H) and according to Lean et al. [2005] for 1610 2005 (data L). In general, the estimation results for the two reconstructions are reasonably well consistent. A significant influence of solar activity on GST with a positive sign was found for two periods, from the late 19th century to the late 1930s and from the latter half of the 1940s to the early 1990s, with no inertia or time delay. In these periods, up to 8 and 25% of the variance of the GST change, respectively, can be attributed to solar activity variations. The solar influence increased in the 1980s to the early 1990s according to data H and began to decrease in the latter half of the 1980s according to data L.

  12. Solar Activity Studies using Microwave Imaging Observations

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.

    2016-01-01

    We report on the status of solar cycle 24 based on polar prominence eruptions (PEs) and microwave brightness enhancement (MBE) information obtained by the Nobeyama radioheliograph. The north polar region of the Sun had near-zero field strength for more than three years (2012-2015) and ended only in September 2015 as indicated by the presence of polar PEs and the lack of MBE. The zero-polar-field condition in the south started only around 2013, but it ended by June 2014. Thus the asymmetry in the times of polarity reversal switched between cycle 23 and 24. The polar MBE is a good proxy for the polar magnetic field strength as indicated by the high degree of correlation between the two. The cross-correlation between the high- and low-latitude MBEs is significant for a lag of approximately 5.5 to 7.3 years, suggesting that the polar field of one cycle indicates the sunspot number of the next cycle in agreement with the Babcock-Leighton mechanism of solar cycles. The extended period of near-zero field in the north-polar region should result in a weak and delayed sunspot activity in the northern hemisphere in cycle 25.

  13. Solar-terrestrial influences on weather and climate; Proceedings of the Symposium, Ohio State University, Columbus, Ohio, August 24-28, 1978

    NASA Technical Reports Server (NTRS)

    Mccormac, B. M. (Editor); Seliga, T. A.

    1979-01-01

    The book contains most of the invited papers and contributions presented at the symposium/workshop on solar-terrestrial influences on weather and climate. Four main issues dominate the activities of the symposium: whether solar variability relationships to weather and climate is a fundamental scientific question to which answers may have important implications for long-term weather and climate prediction; the sun-weather relationships; other potential solar influences on weather including the 11-year sunspot cycle, the 27-day solar rotation, and special solar events such as flares and coronal holes; and the development of practical use of solar variability as a tool for weather and climatic forecasting, other than through empirical approaches. Attention is given to correlation topics; solar influences on global circulation and climate models; lower and upper atmospheric coupling, including electricity; planetary motions and other indirect factors; experimental approaches to sun-weather relationships; and the role of minor atmospheric constituents.

  14. On the statistical relationship between solar activity and spontaneous social processes

    NASA Astrophysics Data System (ADS)

    Rodkin, M. V.; Kharin, E. P.

    2014-12-01

    The starting times of mass spontaneous social movements have been compared with temporal changes in solar activity (Wolf numbers) and in the Aa index of geomagnetic activity. It is shown that relatively high values of solar and, hence, geomagnetic activity are typical (on average) of a set of years when social cataclysms began. In addition, the relationship between social activity and geomagnetic activity is expressed somewhat more strongly than with solar activity. Heliogeomagnetic activity itself is not, however, the cause of social conflicts, as is evidenced by the weakness of the statistical relationship and the fact that the time intervals of an extremely large number of social conflicts (the decades of the 1800s, 1910s, and 1990s) occur during periods of a reduced mean level of solar and geomagnetic activity. From an averaged statistical model of the solar-geomagnetic influence on social activity and the current status and forecast of the 24th solar cycle, we can assume that heliogeomagnetic factors will contribute to an increased level of sociopolitical activity at least until the end of 2014 and, possibly, a little longer.

  15. The solar atmosphere and the structure of active regions. [aircraft accidents, weather

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1975-01-01

    Numerical analyses of solar activities are presented. The effect of these activities on aircraft and weather conditions was studied. Topics considered are: (1) solar flares; (2) solar X-rays; and (3) solar magnetic fields (charts are shown).

  16. Limits of Predictability of Solar Activity

    NASA Astrophysics Data System (ADS)

    Kremliovsky, M. N.

    1995-07-01

    The study of a nonlinear chaotic map of 11-year cycle maxima evolution recently derived from observations is presented with the purpose of predicting the features of the long-term variability of solar activity. It is stressed that dynamical forecast is limited by the Lyapunov time and a statistical approach can be justified due to the ergodic properties of the chaotic evolution. The Gleissberg variation is described as a chaotic walk and its distribution over length is shown to be broad. The global minima are identified as laminar slots of temporal intermittency and their typical distribution over length is also given. We note that a long sunspot cycle can be used as a precursor of the global minimum and a close sequence of global minima (once in approximately 1500 2000 years) may be responsible for the climatic changes (Little Ice Ages).

  17. Active Vibration Damping of Solar Arrays

    NASA Astrophysics Data System (ADS)

    Reinicke, Gunar; Baier, Horst; Grillebeck, Anton; Scharfeld, Frank; Hunger, Joseph; Abou-El-Ela, A.; Lohberg, Andreas

    2012-07-01

    Current generations of large solar array panels are lightweight and flexible constructions to reduce net masses. They undergo strong vibrations during launch. The active vibration damping is one convenient option to reduce vibration responses and limit stresses in facesheets. In this study, two actuator concepts are used for vibration damping. A stack interface actuator replaces a panel hold down and is decoupled from bending moments and shear forces. Piezoelectric patch actuators are used as an alternative, where the number, position and size of actuators are mainly driven by controllability analyses. Linear Quadratic Gaussian control is used to attenuate vibrations of selected mode shapes with both actuators. Simulations as well as modal and acoustic tests show the feasibility of selected actuator concepts.

  18. Solar Activity Forecasting for use in Orbit Prediction

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth

    2001-01-01

    Orbital prediction for satellites in low Earth orbit (LEO) or low planetary orbit depends strongly on exospheric densities. Solar activity forecasting is important in orbital prediction, as the solar UV and EUV inflate the upper atmospheric layers of the Earth and planets, forming the exosphere in which satellites orbit. Geomagnetic effects also relate to solar activity. Because of the complex and ephemeral nature of solar activity, with different cycles varying in strength by more than 100%, many different forecasting techniques have been utilized. The methods range from purely numerical techniques (essentially curve fitting) to numerous oddball schemes, as well as a small subset, called 'Precursor techniques.' The situation can be puzzling, owing to the numerous methodologies involved, somewhat akin to the numerous ether theories near the turn of the last century. Nevertheless, the Precursor techniques alone have a physical basis, namely dynamo theory, which provides a physical explanation for why this subset seems to work. I discuss this solar cycle's predictions, as well as the Sun's observed activity. I also discuss the SODA (Solar Dynamo Amplitude) index, which provides the user with the ability to track the Sun's hidden, interior dynamo magnetic fields. As a result, one may then update solar activity predictions continuously, by monitoring the solar magnetic fields as they change throughout the solar cycle. This paper ends by providing a glimpse into what the next solar cycle (#24) portends.

  19. Growth and Decay of Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Dobias, J. J.; Chapman, G. A.; Cookson, A. M.; Preminger, D. G.; Walton, S. R.

    2002-05-01

    We report here on a study of growth and decay rates of sunspot and facular areas of solar active regions. The data used in this project come from an ongoing program of daily photometric observations of the sun with the Cartesian Full Disk Telescope No. 1 (CFDT1) at the San Fernando Observatory (SFO). Sunspot regions are determined from images taken with a red filter centered at 672.3 nm with a bandpass of 9.7 nm, while images taken with a Ca II K line filter, centered at 393.4 nm and with a bandpass of only 1nm, are used to find facular areas. Before any areas can be found on any observed images, they have to be calibrated then flattened by removing limb darkening thus producing contrast images. Sunspot areas are then determined from any pixel with contrast of -8.5% or less, while any pixel on a K line contrast image with a contrast of +4.8%/μ or higher, where μ is the cosine of the heliocentric angle, is considered to be a facular pixel. To identify the areas as clearly as possible, studied active regions were usually observed on the sun with relatively low activity; that means that each region is either alone on the sun's disk or with only very few other active regions present. Furthermore, to obtain growth and decay patterns of the areas as reliably as possible, only such active regions must be chosen for which there is as complete observational coverage as possible. At the present time studies have been finished for only a few active regions, but analysis of several others is on going. Obtained results will be presented at the meeting. This work is supported by NSF grant ATM-9912132 and NASA grants NAG5-7191 and NAG5-7778.

  20. Solar activity during the deep minimum of 2009

    NASA Astrophysics Data System (ADS)

    Sylwester, Janusz; Siarkowski, Marek; Gburek, Szymon; Gryciuk, Magdalena; Kepa, Anna; Kowaliński, Mirosław; Mrozek, Tomek; Phillips, Kenneth J. H.; Podgórski, Piotr; Sylwester, Barbara

    2014-12-01

    We discuss the character of the unusually deep solar activity minimum of 2009 between Solar Cycles 23 and 24. Levels of solar activity in various parts of the solar atmosphere -- photosphere, chromosphere, transition region, and corona -- were observed to be at their lowest for a century. The soft X-ray emission from the corona (hot outer part of the Sun's atmosphere) was measured throughout most of 2009 with the Polish-built SphinX spectrophotometer. Unlike other X-ray monitoring spacecraft, this sensitive spacecraft-borne instrument was able to continue measurements throughout this extended period of low activity.

  1. Revisiting the question: Does high-latitude solar activity lead low-latitude solar activity in time phase?

    SciTech Connect

    Kong, D. F.; Qu, Z. N.; Guo, Q. L.

    2014-05-01

    Cross-correlation analysis and wavelet transform methods are used to investigate whether high-latitude solar activity leads low-latitude solar activity in time phase or not, using the data of the Carte Synoptique solar filaments archive from 1919 March to 1989 December. From the cross-correlation analysis, high-latitude solar filaments have a time lead of 12 Carrington solar rotations with respect to low-latitude ones. Both the cross-wavelet transform and wavelet coherence indicate that high-latitude solar filaments lead low-latitude ones in time phase. Furthermore, low-latitude solar activity is better correlated with high-latitude solar activity of the previous cycle than with that of the following cycle, which is statistically significant. Thus, the present study confirms that high-latitude solar activity in the polar regions is indeed better correlated with the low-latitude solar activity of the following cycle than with that of the previous cycle, namely, leading in time phase.

  2. Solar Irradiance Variations on Active Region Time Scales

    NASA Technical Reports Server (NTRS)

    Labonte, B. J. (Editor); Chapman, G. A. (Editor); Hudson, H. S. (Editor); Willson, R. C. (Editor)

    1984-01-01

    The variations of the total solar irradiance is an important tool for studying the Sun, thanks to the development of very precise sensors such as the ACRIM instrument on board the Solar Maximum Mission. The largest variations of the total irradiance occur on time scales of a few days are caused by solar active regions, especially sunspots. Efforts were made to describe the active region effects on total and spectral irradiance.

  3. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  4. Influence of nanowires length on performance of crystalline silicon solar cell

    NASA Astrophysics Data System (ADS)

    Li, Haofeng; Jia, Rui; Chen, Chen; Xing, Zhao; Ding, Wuchang; Meng, Yanlong; Wu, Deqi; Liu, Xinyu; Ye, Tianchun

    2011-04-01

    Silicon-nanowire (Si-NW) array, prepared by an electroless chemical-etching method, shows excellent optical antireflection property over a wide spectral bandwidth. The influence of the wire length on the optical antireflection property and the solar cell performance were studied for both the Si-NW array solar cells and the planar solar cells. The reflectance of NWs solar cells is almost invariable and much lower than that of the planar solar cells but the performance of planar solar cells is the best. Results show the performance of NWs solar cells is strongly affected by some other factors such as surface passivation and electrode-contact property.

  5. Models of Impulsively Heated Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Airapetian, Vladimir; Klimchuk, J.

    2009-05-01

    A number of attempts to model solar active regions with steady coronal heating have been modestly successful at reproducing the observed soft X-ray emission, but they fail dramatically at explaining EUV observations. Since impulsive heating (nanoflare) models can reproduce individual EUV loops, it seems reasonable to consider that entire active regions are impulsively heated. However, nanoflares are characterized by many parameters, such as magnitude, duration, and time delay between successive events, and these parameters may depend on the strength of the magnetic field or the length of field lines, for example, so a wide range of active region models must be examined. We have recently begun such a study. Each model begins with a magnetic "skeleton” obtained by extrapolating an observed photospheric magnetogram into the corona. Field lines are populated with plasma using our highly efficient hydro code called Enthalpy Based Thermal Evolution of Loops (EBTEL). We then produce synthetic images corresponding to emission line or broad-band observations. By determining which set of nanoflare parameters best reproduces actual observations, we hope to constrain the properties of the heating and ultimately to reveal the physical mechanism. We here report on the initial progress of our study.

  6. Effects of Solar Magnetic Activity on the Charge States of Minor Ions of Solar Wind

    NASA Astrophysics Data System (ADS)

    Wang, Xuyu

    We present an investigation of the effects of solar magnetic activity on the charge states of minor ions (Fe, Si, Mg, Ne, O, C) in the solar wind using ACE solar wind data, the Current Sheet Source Surface (CSSS) model of the corona and SoHO/MDI data during the 23rd solar cycle. We found that the mean charge states indicate a clear trend to increase with the solar activity when the solar wind speed is above 550 km/s. Below this speed, no significant solar activity dependence is found. When displayed as a function of solar wind speed, iron is different from other elements in that it displays lower charge states in slow wind than in fast wind. The percentages of the high charge states for species with higher m/q (Fe) increase with the solar wind speed, while for the species with lower m/q (Si,Mg, O, C), the percentages of the high charge states decrease with the solar wind speed.

  7. Response of the mesopause temperatures to solar activity over Yakutia in 1999-2013

    NASA Astrophysics Data System (ADS)

    Ammosov, Petr; Gavrilyeva, Galina; Ammosova, Anastasia; Koltovskoi, Igor

    2014-12-01

    OH(6-2) rotational temperature trends and solar cycle effects are studied. Observations were carried out at the Maimaga station (63.04°N, 129.51°E) for the period August 1999 to March 2013. Measurements were conducted with an infrared spectrograph. Temperatures were determined from intensity ratios in the P branch of the OH band. The monthly average residuals of temperature after the subtraction of the mean seasonal variation were used for a search for the solar component of temperature response. The dependence of temperatures on solar activity has been investigated using the Ottawa 10.7 cm flux as a proxy. A linear regression fitting on residual temperatures yields a solar cycle coefficient of 4.24 ± 1.39 K/100 solar flux units (SFU). The cross-correlation analyses showed that changes of the residual temperature follow changes of solar activity with a quasi-two year delay (25 months). The temperature response at the delay of 25 months reaches 7 K/100 SFU. The possible reason of the observed delay can be an influence of quasi-biennial oscillations (QBO) of the atmosphere on the relation of temperature and solar activity. The value of the temperature trend after the subtraction of seasonal and solar components is not statistically significant.

  8. Recent Perplexing Behavior in Solar Activity Indices

    NASA Astrophysics Data System (ADS)

    Lopresto, James C.

    1997-05-01

    Calcium K and Hα and SOHO He II UV plage and sunspot ara have been monitored using images on the INTERNET since November of 1992. The purpose of the project is to determine the degree of correlation between changing plage area and solar irradiance changes (also obtained via the INTERNET). Also the project provides a low cost process to involve undergraduates in astronomy research. When using weighted weekly averages for both spot Hα plage pixel counts, we see the expected decline from the last maximum. The activity continues to decline, or at best, has flattened out over the past several months. In contrast, the K-line plage pixel count from both Big Bear and Sacramento Peak show an upswing since mid-1995 or earlier. The k2 measurments from both Kitt Peak and Sacramento Peak are in general agreement with the spot and Hα behavior, indicating wer are in, or barely passed minimum. Images high in the chromosphere, detailing the magnetic network, may be more senstive to smaller field changes. This might be a partial explanation for the earlier upswing in K line and He 304 activity, which are receiving radiation near or at the top of the chromosphere.

  9. Initiation of non-tropical thunderstorms by solar activity

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Goldberg, R. A.

    1978-01-01

    A theory of thunderstorm initiation is proposed to account for the statistical correlation between solar activity and thunderstorm occurrence in middle to high latitudes. It is suggested that cosmic ray decreases and/or high-energy solar protons associated with active solar events enhance the electric field at low heights so that, if appropriate meteorological conditions are present during a solar event, the atmospheric electric field enhancement may be sufficient to trigger thunderstorm development. Statistical correlations and atmospheric electric effects are described. The theory could be tested if the possible forcing functions and the responding atmospheric electrical and ionic species' characteristics were measured.

  10. Analytical Study of Geomagnetic and Solar Activities During Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Hady, A. A.

    The data of amplitude and phase of most common indicators of geomagnetic activities (especially aa index, A? index) have been analyzed and compared with the solar ac- tivities in the time of solar cycle 23(started from 1996 to 2007). The data taken from NOAA space environment center (SES), USA. during the period starting April 1996 Until Dec. 2001, have been analyzed by power spectrum method. The prediction until year 2007 of geomagnetic activities were studied according to the whole of behavior of solar cycle 23. The results show a good indication of the effects of solar activities on changes of earth climate and weather forecasting. The results are important to various techniques including the operation of low earth orbiting satellites. The climatologi- cal approach makes use of the secular trend since year 1900 until now, by about 15 nanotesla. This indication was recorded too, in solar activity changes during the last century.

  11. Solar Activity, Different Geomagnetic Activity Levels and Acute Myocardial Infarction

    NASA Astrophysics Data System (ADS)

    Dimitrova, Svetla; Jordanova, Malina; Stoilova, Irina; Taseva, Tatiana; Maslarov, Dimitar

    Results on revealing a possible relationship between solar activity (SA) and geomagnetic activity (GMA) and acute myocardial infarction (AMI) morbidity are presented. Studies were based on medical data covering the period from 1.12.1995 to 31.12.2004 and concerned daily distribution of patients with AMI diagnose (in total 1192 cases) from Sofia region on the day of admission at the hospital. Analysis of variance (ANOVA) was applied to check the significance of GMA intensity effect and the type of geomagnetic storms, those caused by Magnetic Clouds (MC) and by High Speed Solar Wind Streams (HSSWS), on AMI morbidity. Relevant correlation coefficients were calculated. Results revealed statistically significant positive correlation between considered GMA indices and AMI. ANOVA revealed that AMI number was signifi- cantly increased from the day before (-1st) till the day after (+1st) geomagnetic storms with different intensities. Geomagnetic storms caused by MC were related to significant increase of AMI number in comparison with the storms caused by HSSWS. There was a trend for such different effects even on -1st and +1st day.

  12. Multi-wavelength solar activity complexes evolution from Solar Dynamic Observatory (SDO)

    NASA Astrophysics Data System (ADS)

    Korolkova, Olga; Benevolenskaya, Elena

    The main problem of the solar physics is to understand a nature of the solar magnetic activity. New space missions and background observations provide us by data describing solar activity with a good space and time resolution. Space missions data observe the solar activity in multi-wavelength emissions come from photosphere to corona. The complex of the solar activity has roots in inte-rior and extends to the solar corona. Thus, modern data give an opportunity to study the activity on the Sun at different levels simultaneously. Solar Dynamics Observatory (SDO) [1] which launched at the beginning of 2010, looks at Sun in different wavelengths such as coronal lines 171Å & 335Å. Also SDO measures photospheric magnetic flux (line-of-sight component of the magnetic field strength) and gives images in continuum. We have studied a stable complexes of the solar activity (about 30 com-plexes) during 6 hours from 10 March 2013 to 14 October 2013 using 720s ca-dence of HMI (Helioseismic and Magnetic Imager) [2] and AIA (Atmospheric Imaging Assembly) [3] instruments of SDO. We have found a good relationship between the magnetic flux and coronal emissions. Here we discuss properties of the complexes in the different levels from photosphere to corona. References 1. W. Dean Pesnell, B.J. Thompson, P.C. Chamberlin // Solar Phys., v. 275, p. 3-15, (2012). 2. P.H. Scherrer, J. Schou, R.I. Bush et al. // Solar Phys., v. 275, p. 207-227, (2012). 3. James R. Lemen • Alan M. Title • David J. Akin et al. // Solar Phys., v. 275, p. 17-40, (2012).

  13. Ionospheric effects of the extreme solar activity of February 1986

    NASA Technical Reports Server (NTRS)

    Boska, J.; Pancheva, D.

    1989-01-01

    During February 1986, near the minimum of the 11 year Solar sunspot cycle, after a long period of totally quiet solar activity (R sub z = 0 on most days in January) a period of a suddenly enhanced solar activity occurred in the minimum between solar cycles 21 and 22. Two proton flares were observed during this period. A few other flares, various phenomena accompanying proton flares, an extremely severe geomagnetic storm and strong disturbances in the Earth's ionosphere were observed in this period of enhanced solar activity. Two active regions appeared on the solar disc. The flares in both active regions were associated with enhancement of solar high energy proton flux which started on 4 February of 0900 UT. Associated with the flares, the magnetic storm with sudden commencement had its onset on 6 February 1312 UT and attained its maximum on 8 February (Kp = 9). The sudden enhancement in solar activity in February 1986 was accompanied by strong disturbances in the Earth's ionosphere, SIDs and ionospheric storm. These events and their effects on the ionosphere are discussed.

  14. Bayesian Infernce for Indentifying Solar Active Regions

    NASA Technical Reports Server (NTRS)

    Pap, Judit; Turmon, Michael; Mukhtar, Saleem

    1997-01-01

    The solar chromosphere consists of three classes-- plage, network, background -- which contribute differently to ultraviolet radiation reaching the earth. Solar physicists are interested in relating plage area and intensity to UV irradiance, as well as understanding the spatial and temporal evolution of plage shapes.

  15. Heliospheric Consecuences of Solar Activity In Several Interplanetary Phenomena

    NASA Astrophysics Data System (ADS)

    Valdés-Galicia, J. F.; Mendoza, B.; Lara, A.; Maravilla, D.

    We have done an analysis of several phenomena related to solar activity such as the total magnetic flux, coronal hole area and sunspots, investigated its long trend evolu- tion over several solar cycles and its possible relationships with interplanetary shocks, sudden storm commencements at earth and cosmic ray variations. Our results stress the physical connection between the solar magnetic flux emergence and the interplan- etary medium dynamics, in particular the importance of coronal hole evolution in the structuring of the heliosphere.

  16. Pre- and main-sequence evolution of solar activity

    NASA Technical Reports Server (NTRS)

    Walter, Frederick M.; Barry, Don C.

    1991-01-01

    The magnetic activity on single solarlike stars declines with stellar age. This has important consequences for the influence of the sun on the early solar system. What is meant by stellar activity, and how it is measured, is reviewed. Stellar activity on the premain-sequence phase of evolution is discussed; the classical T Tauri stars do not exhibit solarlike activity, while the naked T Tauri stars do. The emission surface fluxes of the naked T Tauri stars are similar to those of the youngest main-sequence G stars. The best representation for solarlike stars is a decay proportional to exp(A x t exp 0.5), where A is a function of line excitation temperature. From these decay laws, one can determine the interdependences of the activity, age, and rotation periods. The fluxes of ionizing photons at the earth early in its history are discussed; there was sufficient fluence to account for the observed isotopic ratios of the noble gases.

  17. MAGNETIC ENERGY SPECTRA IN SOLAR ACTIVE REGIONS

    SciTech Connect

    Abramenko, Valentyna; Yurchyshyn, Vasyl

    2010-09-01

    Line-of-sight magnetograms for 217 active regions (ARs) with different flare rates observed at the solar disk center from 1997 January until 2006 December are utilized to study the turbulence regime and its relationship to flare productivity. Data from the SOHO/MDI instrument recorded in the high-resolution mode and data from the BBSO magnetograph were used. The turbulence regime was probed via magnetic energy spectra and magnetic dissipation spectra. We found steeper energy spectra for ARs with higher flare productivity. We also report that both the power index, {alpha}, of the energy spectrum, E(k) {approx} k{sup -}{alpha}, and the total spectral energy, W = {integral}E(k)dk, are comparably correlated with the flare index, A, of an AR. The correlations are found to be stronger than those found between the flare index and the total unsigned flux. The flare index for an AR can be estimated based on measurements of {alpha} and W as A = 10{sup b}({alpha}W){sup c}, with b = -7.92 {+-} 0.58 and c = 1.85 {+-} 0.13. We found that the regime of the fully developed turbulence occurs in decaying ARs and in emerging ARs (at the very early stage of emergence). Well-developed ARs display underdeveloped turbulence with strong magnetic dissipation at all scales.

  18. The Influence of the Solar Cycle on Plasmasphere Refilling

    NASA Astrophysics Data System (ADS)

    Krall, J.; Huba, J.

    2015-12-01

    During refilling, ionospheric plasma streams into the inner magnetosphere from both the northern and southern hemispheres. Plasmasphere refilling rates depend on both the ionospheric sources and on the thermalization of streaming ions. We use the NRL SAMI3 ionosphere/plasmasphere code[1] coupled to the NRLMSIS empirical atmosphere model and the HWM14 empirical wind model, to simulate H+, He+ and O+ populations in the plasmasphere. The SAMI3 ionosphere code includes 7 ion species (H+, He+, O+, N+, O2+, N2+, NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e. Measurements show that refilling rates decrease with increasing solar activity, an effect reproduced by SAMI3 and its two-dimensional cousin, SAMI2. We find that the refilling rate and the resulting the plasmasphere electron content are sensitive to the thermospheric composition and temperature, as well as photoelectron heating and photoproduction rates. Depending on conditions, simulations suggest that the plasmaspheric contribution to the total electron content can either increase or decrease with solar activity, as represented by the daily and 81-day-average F10.7 indices. [1] Huba, J. and J. Krall, 2013, ``Modeling the plasmasphere with SAMI3'', Geophys. Res. Lett. 40, 6--10, doi:10.1029/2012GL054300 Research supported by NRL base funds and the NASA HSR program.

  19. Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

    SciTech Connect

    None,

    1981-09-01

    Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

  20. On the Relationship Between Solar Wind Speed, Geomagnetic Activity, and the Solar Cycle Using Annual Values

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    The aa index can be decomposed into two separate components: the leading sporadic component due to solar activity as measured by sunspot number and the residual or recurrent component due to interplanetary disturbances, such as coronal holes. For the interval 1964-2006, a highly statistically important correlation (r = 0.749) is found between annual averages of the aa index and the solar wind speed (especially between the residual component of aa and the solar wind speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of solar wind speed are inferred to have also trended upward.

  1. Possible relationships between solar activity and atmospheric constituents

    NASA Technical Reports Server (NTRS)

    Roosen, R. G.; Angione, R. J.

    1975-01-01

    The large body of data on solar variations and atmospheric constituents collected between 1902 and 1953 by the Astrophysical Observatory of the Smithsonian Institution (APO) was examined. Short-term variations in amounts of atmospheric aerosols and water vapor due to seasonal changes, volcanic activity, air pollution, and frontal activity are discussed. Preliminary evidence indicates that increased solar activity is at times associated with a decrease in attenuation due to airborne particulates.

  2. Possible relationships between solar activity and atmospheric constituents

    NASA Technical Reports Server (NTRS)

    Roosen, R. G.; Angione, R. J.

    1974-01-01

    The large body of data on solar variations and atmospheric constituents collected between 1902 and 1953 by the Astrophysical Observatory of the Smithsonian Institution (APO) is examined. Short term variations in amounts of atmospheric aerosols and water vapor due to seasonal changes, volcanic activity, air pollution, and frontal activity are discussed. Preliminary evidence indicates that increased solar activity is at times associated with a decrease in attenuation due to airborne particulates.

  3. Solar activity index for long-term ionospheric forecasts

    NASA Astrophysics Data System (ADS)

    Deminov, M. G.

    2016-01-01

    Based on the comparison of solar activity indices (annual average values of the relative number of sunspots Rz 12 and solar radio emission flux at a wavelength of 10.7 cm F 12) with the ionospheric index of solar activity IG 12 for 1954-2013, we have found that the index F 12 is a more accurate (than Rz 12) indicator of solar activity for the long-term forecast of foF2 (the critical frequency of the F2-layer). This advantage of the F 12 index becomes especially significant after 2000 if the specific features of extreme ultraviolet radiation of the Sun are additionally taken into account in the minima of solar cycles, using an appropriate correction to F 12. Qualitative arguments are given in favor of the use of F 12 for the long-term forecast of both foF2 and other ionospheric parameters.

  4. Low-Dimensional Chaos of High-Latitude Solar Activity

    NASA Astrophysics Data System (ADS)

    Li, Qi-Xiu; Li, Ke-Jun

    2007-10-01

    The chaos of high-latitude solar activity has been investigated by determining the behavior of the monthly averaged polar facula counts obtained from the National Astronomical Observatory of Japan (NAOJ) on the basis of nonlinear dynamics theories and methods. It is found that the high-latitude solar activity is also governed by a low-dimensional chaotic attractor in both the northern and southern solar hemispheres, which is the same as that of the low-latitude solar activity. However, their maximal Lyapunov exponents are different, showing different strength of chaos. The maximal Lyapunov exponent (MLE) of polar faculae in the southern solar hemisphere is about 0.0211 ± 0.0003 (month-1), which is nearly consistent with the low-latitude Wolf sunspot numbers, while the MLE in the northern one is approximately 0.0944 ± 0.0066 (month-1), which is obviously greater than the above two.

  5. Recent perspectives in solar physics - Elemental composition, coronal structure and magnetic fields, solar activity

    NASA Technical Reports Server (NTRS)

    Newkirk, G., Jr.

    1975-01-01

    Elemental abundances in the solar corona are studied. Abundances in the corona, solar wind and solar cosmic rays are compared to those in the photosphere. The variation in silicon and iron abundance in the solar wind as compared to helium is studied. The coronal small and large scale structure is investigated, emphasizing magnetic field activity and examining cosmic ray generation mechanisms. The corona is observed in the X-ray and EUV regions. The nature of coronal transients is discussed with emphasis on solar-wind modulation of galactic cosmic rays. A schematic plan view of the interplanetary magnetic field during sunspot minimum is given showing the presence of magnetic bubbles and their concentration in the region around 4-5 AU by a fast solar wind stream.

  6. Solar-collector manufacturing activity, July through December, 1981

    SciTech Connect

    1982-03-01

    Solar thermal collector and solar cell manufacturing activity is both summarized and tabulated. Data are compared for three survey periods (July through December, 1981; January through June, 1981; and July through December, 1980). Annual totals are also provided for the years 1979 through 1981. Data include total producer shipments, end use, market sector, imports and exports. (LEW)

  7. Solar Energy Education. Renewable energy activities for biology

    SciTech Connect

    Not Available

    1982-01-01

    An instructional aid for teachers is presented that will allow biology students the opportunity to learn about renewable energy sources. Some of the school activities include using leaves as collectors of solar energy, solar energy stored in wood, and a fuel value test for green and dry woods. A study of organic wastes as a source of fuel is included. (BCS)

  8. Solar energy education. Renewable energy activities for general science

    SciTech Connect

    Not Available

    1985-01-01

    Renewable energy topics are integrated with the study of general science. The literature is provided in the form of a teaching manual and includes such topics as passive solar homes, siting a home for solar energy, and wind power for the home. Other energy topics are explored through library research activities. (BCS)

  9. Martian induced magnetosphere variations with solar activity cycle

    NASA Astrophysics Data System (ADS)

    Fedorov, Andrey; Ronan, Modolo; Jarninen, Riku; Mazelle, Christian; Barabash, Stas

    2014-05-01

    During the last 6 years of ESA Mars Express mission we have accumulated plasma data taken inside and around the Martian induced magnetosphere corresponding to the increasing branch of solar activity. This data allows to make an enhanced study of the magnetosphere variations as a response of the solar activity level. Since Mars Express has no onboard magnetometer, we used the hybrid models of the Martian plasma environment to get a proper frame to make an adequate statistics of the magnetospheric response. In this paper we present a spatial distribution of the planetary plasma in the planetary wake as well as the ionsospheric escape as a function of the solar activity.

  10. Intraocular pressure (IOP) in relation to four levels of daily geomagnetic and extreme yearly solar activity.

    PubMed

    Stoupel, E; Goldenfeld, M; Shimshoni, M; Siegel, R

    1993-02-01

    The link between geomagnetic field activity (GMA), solar activity and intraocular pressure (IOP) in healthy individuals was investigated. The IOP of 485 patients (970 eyes) was recorded over three nonconsecutive years (1979, 1986, 1989) which were characterized by maximal solar activity (1979, 1989) or minimal solar activity (1986). The measurements were also correlated with four categories of GMA activity: quiet (level I0), unsettled (II0), active (III0), and stormy (IV0). Participants were also differentiated by age and sex. We found that IOP was lowest on days of level IV0 (stromy) GMA. The drop in IOP concomitant with a decrease in GMA level was more significant during periods of low solar activity and in persons over 65 years of age. There was a trend towards higher IOP values on days of levels II0 and IV0 GMA in years of high solar activity. Differences between the sexes and among individuals younger than 65 years were not significant. Our results show an interesting aspect of environmental influence on the healthy population. PMID:8468099

  11. Influenza pandemics, solar activity cycles, and vitamin D.

    PubMed

    Hayes, Daniel P

    2010-05-01

    There is historic evidence that influenza pandemics are associated with solar activity cycles (the Schwabe-cycle of about 11-years periodicity). The hypothesis is presented and developed that influenza pandemics are associated with solar control of vitamin D levels in humans which waxes and wanes in concert with solar cycle dependent ultraviolet radiation. It is proposed that this solar cycle dependence arises both directly from cyclic control of the amount of ultraviolet radiation as well as indirectly through cyclic control of atmospheric circulation and dynamics. PMID:20056531

  12. Influence of External Pressure on the Performance of Quantum Dot Solar Cells.

    PubMed

    Kim, Jaehoon; Jeong, Byeong Guk; Roh, Heebum; Song, Jiyun; Park, Myeongjin; Lee, Doh C; Bae, Wan Ki; Lee, Changhee

    2016-09-14

    We report the influence of post-treatment via the external pressure on the device performance of quantum dot (QD) solar cells. The structural analysis together with optical and electrical characterization on QD solids reveal that the external pressure compacts QD active layers by removing the mesoscopic voids and enhances the charge carrier transport along QD solids, leading to significant increase in JSC of QD solar cells. Increasing the external pressure, by contrast, accompanies reduction in FF and VOC, yielding the trade-off relationship among JSC and FF and VOC in PCE of devices. Optimization at the external pressure in the present study at 1.4-1.6 MPa enables us to achieve over 10% increase in PCE of QD solar cells. The approach and results show that the control over the organization of QDs is the key for the charge transport properties in ensemble and also offer simple yet effective mean to enhance the electrical performance of transistors and solar cells using QDs. PMID:27549664

  13. The influence of cloud cover index on the accuracy of solar irradiance model estimates

    NASA Astrophysics Data System (ADS)

    Martins, F. R.; Silva, S. A. B.; Pereira, E. B.; Abreu, S. L.

    2008-04-01

    Cloud cover index ( CCI) obtained from satellite images contains information on cloud amount and their optical thickness. It is the chief climate data for the assessment of solar energy resources in most radiative transfer models, particularly for the model BRASIL-SR that is currently operational at CPTEC. The wide range of climate environments in Brazil turns CCI determination into a challenging activity and great effort has been directed to develop new methods and procedures to improve the accuracy of these estimations from satellite images (Martins 2001; Martins et al. 2003a; Ceballos et al. 2004). This work demonstrates the influence of CCI determination methods on estimates of surface solar irradiances obtained by the model BRASIL-SR comparing deviations among ground data and model results. Three techniques using visible and/or thermal infrared images of GOES-8 were employed to generate the CCI for input into the model BRASIL-SR. The ground-truth data was provided by the solar radiation station located at Caicó/PE, in Brazilian Northeast region, which is part of the UNEP/GEF project SWERA (Solar and Wind Energy Resources Assessment). Results have shown that the application of the bi-spectral techniques have reduced mean bias error up to 66% and root mean square error up to 50% when compared to the usual technique for CCI determination based on the straightforward determination of month-by-month extremes for maximum and minimum cloud states.

  14. A Solar Cycle Dependence of Nonlinearity in Magnetospheric Activity

    SciTech Connect

    Johnson, Jay R; Wing, Simon

    2005-03-08

    The nonlinear dependencies inherent to the historical K(sub)p data stream (1932-2003) are examined using mutual information and cumulant based cost as discriminating statistics. The discriminating statistics are compared with surrogate data streams that are constructed using the corrected amplitude adjustment Fourier transform (CAAFT) method and capture the linear properties of the original K(sub)p data. Differences are regularly seen in the discriminating statistics a few years prior to solar minima, while no differences are apparent at the time of solar maximum. These results suggest that the dynamics of the magnetosphere tend to be more linear at solar maximum than at solar minimum. The strong nonlinear dependencies tend to peak on a timescale around 40-50 hours and are statistically significant up to one week. Because the solar wind driver variables, VB(sub)s and dynamical pressure exhibit a much shorter decorrelation time for nonlinearities, the results seem to indicate that the nonlinearity is related to internal magnetospheric dynamics. Moreover, the timescales for the nonlinearity seem to be on the same order as that for storm/ring current relaxation. We suggest that the strong solar wind driving that occurs around solar maximum dominates the magnetospheric dynamics suppressing the internal magnetospheric nonlinearity. On the other hand, in the descending phase of the solar cycle just prior to solar minimum, when magnetospheric activity is weaker, the dynamics exhibit a significant nonlinear internal magnetospheric response that may be related to increased solar wind speed.

  15. The influence of absorbed solar radiation by Saharan dust on hurricane genesis

    NASA Astrophysics Data System (ADS)

    Bretl, Sebastian; Reutter, Philipp; Raible, Christoph C.; Ferrachat, Sylvaine; Poberaj, Christina Schnadt; Revell, Laura E.; Lohmann, Ulrike

    2015-03-01

    To date, the radiative impact of dust and the Saharan air layer (SAL) on North Atlantic hurricane activity is not yet known. According to previous studies, dust stabilizes the atmosphere due to absorption of solar radiation but thus shifts convection to regions more conducive for hurricane genesis. Here we analyze differences in hurricane genesis and frequency from ensemble sensitivity simulations with radiatively active and inactive dust in the aerosol-climate model ECHAM6-HAM. We investigate dust burden and other hurricane-related variables and determine their influence on disturbances which develop into hurricanes (developing disturbances, DDs) and those which do not (nondeveloping disturbances, NDDs). Dust and the SAL are found to potentially have both inhibiting and supporting influences on background conditions for hurricane genesis. A slight southward shift of DDs is determined when dust is active as well as a significant warming of the SAL, which leads to a strengthening of the vertical circulation associated with the SAL. The dust burden of DDs is smaller in active dust simulations compared to DDs in simulations with inactive dust, while NDDs contain more dust in active dust simulations. However, no significant influence of radiatively active dust on other variables in DDs and NDDs is found. Furthermore, no substantial change in the DD and NDD frequency due to the radiative effects of dust can be detected.

  16. Influence of Atmospheric Solar Radiation Absorption on Photodestruction of Ions at D-Region Altitudes of the Ionosphere

    NASA Astrophysics Data System (ADS)

    Pavlov, A. V.

    2016-07-01

    The influence of atmospheric solar radiation absorption on the photodetachment, dissociative photodetachment, and photodissociation rate coefficients (photodestruction rate coefficients) of O-, Cl-, O2 -, O3 -, OH-, NO2 -, NO3 -, O4 -, OH-(H2O), CO3 -, CO4 -, ONOO-, HCO3 -, CO3 -(H2O), NO3 -(H2O), O2 +(H2O), O4 +, N4 +, NO+(H2O), NO+(H2O)2, H+(H2O) n for n = 2-4, NO+(N2), and NO+(CO2) at D-region altitudes of the ionosphere is studied. A numerical one-dimensional time-dependent neutral atmospheric composition model has been developed to estimate this influence. The model simulations are carried out for the geomagnetically quiet time period of 15 October 1998 at moderate solar activity over the Boulder ozonesonde. If the solar zenith angle is not more than 90° then the strongest influence of atmospheric solar radiation absorption on photodestruction of ions is found for photodissociation of CO4 - ions when CO3 - ions are formed. It follows from the calculations that decreases in the photodestruction rate coefficients of ions under consideration caused by this influence are less than 2 % at 70 km altitude and above this altitude if the solar zenith angle does not exceed 90°.

  17. Influence of Atmospheric Solar Radiation Absorption on Photodestruction of Ions at D-Region Altitudes of the Ionosphere

    NASA Astrophysics Data System (ADS)

    Pavlov, A. V.

    2016-04-01

    The influence of atmospheric solar radiation absorption on the photodetachment, dissociative photodetachment, and photodissociation rate coefficients (photodestruction rate coefficients) of O-, Cl-, O2 -, O3 -, OH-, NO2 -, NO3 -, O4 -, OH-(H2O), CO3 -, CO4 -, ONOO-, HCO3 -, CO3 -(H2O), NO3 -(H2O), O2 +(H2O), O4 +, N4 +, NO+(H2O), NO+(H2O)2, H+(H2O) n for n = 2-4, NO+(N2), and NO+(CO2) at D-region altitudes of the ionosphere is studied. A numerical one-dimensional time-dependent neutral atmospheric composition model has been developed to estimate this influence. The model simulations are carried out for the geomagnetically quiet time period of 15 October 1998 at moderate solar activity over the Boulder ozonesonde. If the solar zenith angle is not more than 90° then the strongest influence of atmospheric solar radiation absorption on photodestruction of ions is found for photodissociation of CO4 - ions when CO3 - ions are formed. It follows from the calculations that decreases in the photodestruction rate coefficients of ions under consideration caused by this influence are less than 2 % at 70 km altitude and above this altitude if the solar zenith angle does not exceed 90°.

  18. Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

    NASA Astrophysics Data System (ADS)

    Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

    2013-01-01

    Abstract<p label="1">By integrating and averaging the auroral brightness from Polar Ultraviolet Imager auroral images, which have the whole auroral ovals, and combining the observation data of interplanetary magnetic field (IMF) and <span class="hlt">solar</span> wind from NASA Operating Missions as a Node on the Internet (OMNI), we investigate the <span class="hlt">influence</span> of IMF and <span class="hlt">solar</span> wind on auroral <span class="hlt">activities</span>, and analyze the separate roles of the <span class="hlt">solar</span> wind dynamic pressure, density, and velocity on aurora, respectively. We statistically analyze the relations between the interplanetary conditions and the auroral brightness in dawnside, dayside, duskside, and nightside. It is found that the three components of the IMF have different effects on the auroral brightness in the different regions. Different from the nightside auroral brightness, the dawnside, dayside, and duskside auroral brightness are affected by the IMF Bx, and By components more significantly. The IMF Bx and By components have different effects on these three regional auroral brightness under the opposite polarities of the IMF Bz. As expected, the nightside aurora is mainly affected by the IMF Bz, and under southward IMF, the larger the |Bz|, the brighter the nightside aurora. The IMF Bx and By components have no visible effects. On the other hand, it is also found that the aurora is not intensified singly with the increase of the <span class="hlt">solar</span> wind dynamic pressure: when only the dynamic pressure is high, but the <span class="hlt">solar</span> wind velocity is not very fast, the aurora will not necessarily be intensified significantly. These results can be used to qualitatively predict the auroral <span class="hlt">activities</span> in different regions for various interplanetary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780019594','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780019594"><span id="translatedtitle">Preliminary design <span class="hlt">activities</span> for <span class="hlt">solar</span> heating and cooling systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1978-01-01</p> <p>Information on the development of <span class="hlt">solar</span> heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design <span class="hlt">activities</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008639','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008639"><span id="translatedtitle">Effects of Low <span class="hlt">Activity</span> <span class="hlt">Solar</span> Cycle on Orbital Debris Lifetime</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cable, Samual B.; Sutton, Eric K.; Lin, chin S.; Liou, J.-C.</p> <p>2011-01-01</p> <p>Long duration of low <span class="hlt">solar</span> <span class="hlt">activity</span> in the last <span class="hlt">solar</span> minimum has an undesirable consequence of extending the lifetime of orbital debris. The AFRL TacSat-2 satellite decommissioned in 2008 has finally re-entered into the atmosphere on February 5th after more than one year overdue. Concerning its demise we have monitored its orbital decay and monthly forecasted Tacsat-2 re-entry since September 2010 by using the Orbital Element Prediction (OEP) model developed by the AFRL Orbital Drag Environment program. The model combines estimates of future <span class="hlt">solar</span> <span class="hlt">activity</span> with neutral density models, drag coefficient models, and an orbit propagator to predict satellite lifetime. We run the OEP model with <span class="hlt">solar</span> indices forecast by the NASA Marshall <span class="hlt">Solar</span> <span class="hlt">Activity</span> Future Estimation model, and neutral density forecast by the MSIS-00 neutral density model. Based on the two line elements in 2010 up to mid September, we estimated at a 50% confidence level TacSat-2's re-entry time to be in early February 2011, which turned out to be in good agreement with Tacsat-2's actual re-entry date. The potential space weather effects of the coming low <span class="hlt">activity</span> <span class="hlt">solar</span> cycle on satellite lifetime and orbital debris population are examined. The NASA long-term orbital debris evolutionary model, LEGEND, is used to quantify the effects of <span class="hlt">solar</span> flux on the orbital debris population in the 200-600 km altitude environment. The results are discussed for developing satellite orbital drag application product.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.1619Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.1619Z"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> dependence of nightside aurora in winter conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Su; Luan, Xiaoli; Dou, Xiankang</p> <p>2016-02-01</p> <p>The dependence of the nightside (21:00-03:00 MLT; magnetic local time) auroral energy flux on <span class="hlt">solar</span> <span class="hlt">activity</span> was quantitatively studied for winter/dark and geomagnetically quiet conditions. Using data combined from Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager and Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations, we separated the effects of geomagnetic <span class="hlt">activity</span> from those of <span class="hlt">solar</span> flux on the nightside auroral precipitation. The results showed that the nightside auroral power was reduced by ~42% in <span class="hlt">solar</span> maximum (F10.7 = 200 sfu; <span class="hlt">solar</span> flux unit 1 sfu = 10-22 W m-2 Hz-1) with respect to that under <span class="hlt">solar</span> minimum (F10.7 = 70 sfu) for the Kp = 1 condition, and this change rate became less (~21%) for the Kp = 3 condition. In addition, the <span class="hlt">solar</span> cycle dependence of nightside auroral power was similar with that from both the premidnight (21:00-23:00 MLT) and postmidnight (01:00-03:00 MLT) sectors. These results indicated that as the ionospheric ionization increases with the enhanced auroral and geomagnetic <span class="hlt">activities</span>, the <span class="hlt">solar</span> <span class="hlt">activity</span> dependences of nightside auroral power become weaker, at least under geomagnetically quiet conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH33D..07K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH33D..07K"><span id="translatedtitle">The <span class="hlt">Solar</span> Non-<span class="hlt">activity</span> Cycle of Polar Coronal Holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirk, M. S.; Pesnell, W. D.; Young, C. A.</p> <p>2015-12-01</p> <p>After the unusually extended minimum in 2008 and 2009, <span class="hlt">solar</span> cycle 24 continues to be an exceptionally weak cycle both in sunspot number and number of large magnetic storms. Coronal holes offer a direct measurement of the non-<span class="hlt">activity</span> <span class="hlt">solar</span> cycle, a missing link in our understanding of <span class="hlt">solar</span> cycle progression. They are prevalent during <span class="hlt">solar</span> minimum, non-axisymmetric, and are stable. Polar coronal holes are regularly observed capping the northern and southern <span class="hlt">solar</span> poles in EUV images of the corona and are understood as the primary source of the fast <span class="hlt">solar</span> wind. We make measurements of these features from 1996 through 2015 using four different NASA imagers: SOHO EIT, STEREO A and B EUVI, and SDO AIA. A measurement of the axial symmetry of the polar holes is seen to have clear <span class="hlt">solar</span> cycle dependence. Polar coronal holes are aligned with the <span class="hlt">solar</span> rotation axis during minimum and have a maximum asymmetry between holes of about 14 degrees in the declining phase of the current <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhA.114.1361Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhA.114.1361Z"><span id="translatedtitle"><span class="hlt">Influence</span> of morphology of PCDTBT:PC71BM on the performance of <span class="hlt">solar</span> cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Ling; Zhao, Suling; Xu, Zheng; Gong, Wei; Yang, Qianqian; Fan, Xing; Xu, Xurong</p> <p>2014-03-01</p> <p>Because of the restriction of low energy difference between the highest occupied molecular orbital of P3HT and the lowest unoccupied molecular orbital of PCBM, the obtained power conversion efficiency of P3HT:PCBM <span class="hlt">solar</span> cells is merely half the ideal value. In this paper, we have fabricated bulk heterojunction <span class="hlt">solar</span> cells based on PCDTBT and PC71BM (structure: ITO/PEDOT:PSS/PCDTBT:PC71BM/LiF (0.8 nm)/Al (80 nm)). In order to optimize the performance of the cells, the weight ratio of PCDTBT to PC71BM, the thickness of the <span class="hlt">active</span> layer and thermal annealing are investigated. When the weight ratio of PCDTBT to PC71BM is 1:2 and the thickness of the <span class="hlt">active</span> layer is 73 nm, a short circuit current density of 10.36 mA/cm2, an open-circuit voltage of 0.91 V, a fill factor of 55.06 % and a power conversion efficiency of 5.19 % can be achieved. Moreover, we probe the <span class="hlt">influence</span> of annealing temperature on the performance of organic <span class="hlt">solar</span> cells, and find that the thermal treatment methodology (apart from the removal of trapped casting solvent) is of limited benefit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSH33A2035S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSH33A2035S"><span id="translatedtitle">Radio Imaging Observations of <span class="hlt">Solar</span> <span class="hlt">Activity</span> Cycle and Its Anomaly</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shibasaki, K.</p> <p>2011-12-01</p> <p>The 24th <span class="hlt">solar</span> <span class="hlt">activity</span> cycle has started and relative sunspot numbers are increasing. However, their rate of increase is rather slow compared to previous cycles. <span class="hlt">Active</span> region sizes are small, lifetime is short, and big (X-class) flares are rare so far. We study this anomalous situation using data from Nobeyama Radioheliograph (NoRH). Radio imaging observations have been done by NoRH since 1992. Nearly 20 years of daily radio images of the Sun at 17 GHz are used to synthesize a radio butterfly diagram. Due to stable operation of the instrument and a robust calibration method, uniform datasets are available covering the whole period of observation. The radio butterfly diagram shows bright features corresponding to <span class="hlt">active</span> region belts and their migration toward low latitude as the <span class="hlt">solar</span> cycle progresses. In the present <span class="hlt">solar</span> <span class="hlt">activity</span> cycle (24), increase of radio brightness is delayed and slow. There are also bright features around both poles (polar brightening). Their brightness show <span class="hlt">solar</span> cycle dependence but peaks around <span class="hlt">solar</span> minimum. Comparison between the last minimum and the previous one shows decrease of its brightness. This corresponds to weakening of polar magnetic field <span class="hlt">activity</span> between them. In the northern pole, polar brightening is already weakened in 2011, which means it is close to <span class="hlt">solar</span> maximum in the northern hemisphere. Southern pole does not show such feature yet. Slow rise of <span class="hlt">activity</span> in <span class="hlt">active</span> region belt, weakening of polar <span class="hlt">activity</span> during the minimum, and large north-south asymmetry in polar <span class="hlt">activity</span> imply that global <span class="hlt">solar</span> <span class="hlt">activity</span> and its synchronization are weakening.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900018856','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900018856"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span>, the QBO, and tropospheric responses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tinsley, Brian A.; Brown, Geoffrey M.; Scherrer, Philip H.</p> <p>1989-01-01</p> <p>The suggestion that galactic cosmic rays (GCR) as modulated by the <span class="hlt">solar</span> wind are the carriers of the component of <span class="hlt">solar</span> variability that affects weather and climate has been discussed in the literature for 30 years, and there is now a considerable body of evidence that supports it. Variations of GCR occur with the 11 year <span class="hlt">solar</span> cycle, matching the time scale of recent results for atmospheric variations, as modulated by the quasibiennial oscillation of equatorial stratospheric winds (the QBO). Variations in GCR occur on the time scale of centuries with a well defined peak in the coldest decade of the little ice age. New evidence is presented on the meteorological responses to GCR variations on the time scale of a few days. These responses include changes in the vertical temperature profile in the troposphere and lower stratosphere in the two days following <span class="hlt">solar</span> flare related high speed plasma streams and associated GCR decreases, and in decreases in Vorticity Area Index (VAI) following Forbush decreases of GCR. The occurrence of correlations of GCR and meteorological responses on all three time scales strengthens the hypothesis of GCR as carriers of <span class="hlt">solar</span> variability to the lower atmosphere. Both short and long term tropospheric responses are understandable as changes in the intensity of cyclonic storms initiated by mechanisms involving cloud microphysical and cloud electrification processes, due to changes in local ion production from changes in GCR fluxes and other high energy particles in the MeV to low GeV range. The nature of these mechanisms remains undetermined. Possible stratospheric wind (particularly QBO) effects on the transport of HNO3 and other constituents incorporated in cluster ions and possible condensation and freezing nuclei are considered as relevant to the long term variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790002474','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790002474"><span id="translatedtitle">Effect of <span class="hlt">solar</span> <span class="hlt">activity</span> on the frequency of occurrence of major anomalies in the Arctic. [weather forecasting</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bolotinskaya, M. S.</p> <p>1978-01-01</p> <p>Major air pressure and temperature anomalies in certain arctic regions were studied with a view toward predicting their occurrence. Correlations are sought between the frequency of arctic anomalies and <span class="hlt">solar</span> <span class="hlt">activity</span>, or specifically the Wolf number and the index of geomagnetic disturbance. Graphic techniques are used to show that <span class="hlt">solar</span> <span class="hlt">activity</span> has a definite <span class="hlt">influence</span> on the frequency of occurrence of major anomalies of pressure and temperature in the Arctic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6617349','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6617349"><span id="translatedtitle"><span class="hlt">Active</span> <span class="hlt">solar</span> heating and cooling information user study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.</p> <p>1981-01-01</p> <p>The results of a series of telephone interviews with groups of users of information on <span class="hlt">active</span> <span class="hlt">solar</span> heating and cooling (SHAC). An earlier study identified the information user groups in the <span class="hlt">solar</span> community and the priority (to accelerate <span class="hlt">solar</span> energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from 19 SHAC groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Manufacturers (4 groups), Distributors, Installers, Architects, Builders, Planners, Engineers (2 groups), Representatives of Utilities, Educators, Cooperative Extension Service County Agents, Building Owners/Managers, and Homeowners (2 groups). The data will be used as input to the determination of information products and services the <span class="hlt">Solar</span> Energy Research Institute, the <span class="hlt">Solar</span> Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21557069','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21557069"><span id="translatedtitle">CHEMI-IONIZATION IN <span class="hlt">SOLAR</span> PHOTOSPHERE: <span class="hlt">INFLUENCE</span> ON THE HYDROGEN ATOM EXCITED STATES POPULATION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mihajlov, Anatolij A.; Ignjatovic, Ljubinko M.; Sreckovic, Vladimir A.; Dimitrijevic, Milan S. E-mail: mihajlov@ipb.ac.rs</p> <p>2011-03-15</p> <p>In this paper, the <span class="hlt">influence</span> of chemi-ionization processes in H*(n {>=} 2) + H(1s) collisions, as well as the <span class="hlt">influence</span> of inverse chemi-recombination processes on hydrogen atom excited-state populations in <span class="hlt">solar</span> photosphere, are compared with the <span class="hlt">influence</span> of concurrent electron-atom and electron-ion ionization and recombination processes. It has been found that the considered chemi-ionization/recombination processes dominate over the relevant concurrent processes in almost the whole <span class="hlt">solar</span> photosphere. Thus, it is shown that these processes and their importance for the non-local thermodynamic equilibrium modeling of the <span class="hlt">solar</span> atmosphere should be investigated further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010037770','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010037770"><span id="translatedtitle">A Time-Frequency Analysis of the Effects of <span class="hlt">Solar</span> <span class="hlt">Activities</span> on Tropospheric Thermodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiang, Richard K.; Kyle, H. Lee; Wharton, Stephen W. (Technical Monitor)</p> <p>2001-01-01</p> <p>Whether the Sun has significantly <span class="hlt">influenced</span> the climate during the last century has been under extensive debates for almost two decades. Since the <span class="hlt">solar</span> irradiance varies very little in a <span class="hlt">solar</span> cycle, it is puzzling that some geophysical parameters show proportionally large variations which appear to be responding to the <span class="hlt">solar</span> cycles. For example, variation in low altitude clouds is shown correlated with <span class="hlt">solar</span> cycle, and the onset of Forbush decrease is shown correlated with the reduction of the vorticity area index. A possible sun-climate connection is that galactic cosmic rays modulated by <span class="hlt">solar</span> <span class="hlt">activities</span> <span class="hlt">influence</span> cloud formation. In this paper, we apply wavelet transform to satellite and surface data to examine this hypothesis. Data analyzed include the time series for <span class="hlt">solar</span> irradiance, sunspots, UV index, temperature, cloud coverage, and neutron counter measurements. The interactions among the elements in the Earth System under the external and internal forcings give out very complex signals.The periodicity of the forcings or signals could range widely. Since wavelet transforms can analyze multi-scale phenomena that are both localized in frequency and time, it is a very useful technique for detecting, understanding and monitoring climate changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950033056&hterms=Hysteresis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHysteresis','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950033056&hterms=Hysteresis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHysteresis"><span id="translatedtitle">Observations of hysteresis in <span class="hlt">solar</span> cycle variations among seven <span class="hlt">solar</span> <span class="hlt">activity</span> indicators</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bachmann, Kurt T.; White, Oran R.</p> <p>1994-01-01</p> <p>We show that smoothed time series of 7 indices of <span class="hlt">solar</span> <span class="hlt">activity</span> exhibit significant <span class="hlt">solar</span> cycle dependent differences in their relative variations during the past 20 years. In some cases these observed hysteresis patterns start to repeat over more than one <span class="hlt">solar</span> cycle, giving evidence that this is a normal feature of <span class="hlt">solar</span> variability. Among the indices we study, we find that the hysteresis effects are approximately simple phase shifts, and we quantify these phase shifts in terms of lag times behind the leading index, the International Sunspot Number. Our measured lag times range from less than one month to greater than four months and can be much larger than lag times estimated from short-term variations of these same <span class="hlt">activity</span> indices during the emergence and decay of major <span class="hlt">active</span> regions. We argue that hysteresis represents a real delay in the onset and decline of <span class="hlt">solar</span> <span class="hlt">activity</span> and is an important clue in the search for physical processes responsible for changing <span class="hlt">solar</span> emission at various wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9519L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9519L"><span id="translatedtitle"><span class="hlt">Influence</span> of interplanetary <span class="hlt">solar</span> wind sector polarity on the ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>liu, jing</p> <p>2014-05-01</p> <p>Knowledge of <span class="hlt">solar</span> sector polarity effects on the ionosphere may provide some clues in understanding of the ionospheric day-to-day variability. A <span class="hlt">solar</span>-terrestrial connection ranging from <span class="hlt">solar</span> sector boundary (SB) crossings, geomagnetic disturbance and ionospheric perturbations has been demonstrated. The increases in interplanetary <span class="hlt">solar</span> wind speed within three days are seen after SB crossings, while the decreases in <span class="hlt">solar</span> wind dynamic pressure and magnetic field intensity immediately after SB crossings are confirmed by the superposed epoch analysis results. Furthermore, the interplanetary magnetic field (IMF) Bz component turns from northward to southward in March equinox and June solstice as the Earth passes from a <span class="hlt">solar</span> sector of outward to inward directed magnetic fields, whereas the reverse situation occurs for the transition from toward to away sectors. The F2 region critical frequency (foF2) covering about four <span class="hlt">solar</span> cycles and total electron content (TEC) during 1998-2011 are utilized to extract the related information, revealing that they are not modified significantly and vary within the range of 15% on average. The responses of the ionospheric TEC to SB crossings exhibit complex temporal and spatial variations and have strong dependencies on season, latitude, and <span class="hlt">solar</span> cycle. This effect is more appreciable in equinoctial months than in solstitial months, which is mainly caused by larger southward Bz components in equinox. In September equinox, latitudinal profile of relative variations of foF2 at noon is featured by depressions at high latitudes and enhancements in low-equatorial latitudes during IMF away sectors. The negative phase of foF2 is delayed at <span class="hlt">solar</span> minimum relative to it during other parts of <span class="hlt">solar</span> cycle, which might be associated with the difference in longevity of major interplanetary <span class="hlt">solar</span> wind drivers perturbing the Earth's environment in different phases of <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995IJBm...38...89S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995IJBm...38...89S"><span id="translatedtitle">Relationship between immunoglobulin levels and extremes of <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stoupel, Elijahu G.; Abramson, Eugene; Gabbay, Uri; Pick, Albert I.</p> <p>1995-06-01</p> <p>The possible relationship between epidemics and extremes of <span class="hlt">solar</span> <span class="hlt">activity</span> has been discussed previously. The purpose of the present study was to verify whether differences in the levels of immunoglobulins (IgA, IgG, IgM) could be noted at the highest (July 1989) and lowest (September 1986) points of the last (21st) and present (22nd) 11-year <span class="hlt">solar</span> cycle. The work was divided into a 1-month study (covering the month of minimal or maximal <span class="hlt">solar</span> <span class="hlt">activity</span>), a 3-month study (1 month before and after the month of minimal or maximal <span class="hlt">solar</span> <span class="hlt">activity</span>) and a 5-month study (2 months before and after the month of minimal or maximal <span class="hlt">solar</span> <span class="hlt">activity</span>). A trend of a drop-off for all three immunoglobulins was seen on the far side of the maximal point of the <span class="hlt">solar</span> cycle. Statistical significance was achieved in the 5-month study for IgM ( P=0.04), and a strong trend was shown for IgG ( P=0.07). Differences between the sexes were also noted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820041908&hterms=variability+climate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dvariability%2Bclimate','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820041908&hterms=variability+climate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dvariability%2Bclimate"><span id="translatedtitle">The <span class="hlt">influence</span> of <span class="hlt">solar</span> ultraviolet variability on climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chamberlain, J. W.</p> <p>1982-01-01</p> <p>Changes in the <span class="hlt">solar</span> u.v. flux and its wavelength distribution could affect the climate both directly and through the greenhouse effect of the ozone shield. Indeed, the ozone content of the stratosphere is highly sensitive to the relative intensity of two broad spectral regions in the <span class="hlt">solar</span> u.v. The observed amplitude for global-ozone variation of a few percent at most over the <span class="hlt">solar</span> cycle is compatible with a variation of <span class="hlt">solar</span> u.v. flux of no more than about 20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1260817','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1260817"><span id="translatedtitle">Do <span class="hlt">solar</span> cycles <span class="hlt">influence</span> giant cell arteritis and rheumatoid arthritis incidence?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wing, Simon; Rider, Lisa G.; Johnson, Jay R.; Miller, Federick W.; Matteson, Eric L.; Crowson, C. S.; Gabriel, S. E.</p> <p>2015-05-15</p> <p>Our objective was to examine the <span class="hlt">influence</span> of <span class="hlt">solar</span> cycle and geomagnetic effects on the incidence of giant cell arteritis (GCA) and rheumatoid arthritis (RA). Methods: We used data from patients with GCA (1950-2004) and RA (1955-2007) obtained from population-based cohorts. Yearly trends in age-adjusted and sex-adjusted incidence were correlated with the F10.7 index (<span class="hlt">solar</span> radiation at 10.7 cm wavelength, a proxy for the <span class="hlt">solar</span> extreme ultraviolet radiation) and AL index (a proxy for the westward auroral electrojet and a measure of geomagnetic <span class="hlt">activity</span>). Fourier analysis was performed on AL, F10.7, and GCA and RA incidence rates. Results: The correlation of GCA incidence with AL is highly significant: GCA incidence peaks 0-1 year after the AL reaches its minimum (ie, auroral electrojet reaches a maximum). The correlation of RA incidence with AL is also highly significant. RA incidence rates are lowest 5-7 years after AL reaches maximum. AL, GCA and RA incidence power spectra are similar: they have a main peak (periodicity) at about 10 years and a minor peak at 4-5 years. However, the RA incidence power spectrum main peak is broader (8-11 years), which partly explains the lower correlation between RA onset and AL. The auroral electrojets may be linked to the decline of RA incidence more strongly than the onset of RA. The incidences of RA and GCA are aligned in geomagnetic latitude. Conclusions: AL and the incidences of GCA and RA all have a major periodicity of about 10 years and a secondary periodicity at 4-5 years. Geomagnetic <span class="hlt">activity</span> may explain the temporal and spatial variations, including east-west skewness in geographic coordinates, in GCA and RA incidence, although the mechanism is unknown. Lastly, the link with <span class="hlt">solar</span>, geospace and atmospheric parameters need to be investigated. These novel findings warrant examination in other populations and with other autoimmune diseases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890042166&hterms=activity+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dactivity%2Btheory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890042166&hterms=activity+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dactivity%2Btheory"><span id="translatedtitle">Polarization aberrations in the <span class="hlt">solar</span> <span class="hlt">activity</span> measurements experiments (SAMEX) <span class="hlt">solar</span> vector magnetograph</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcguire, James P., Jr.; Chipman, Russell A.</p> <p>1989-01-01</p> <p>An optical design and polarization analysis of the Air Force/NASA <span class="hlt">Solar</span> <span class="hlt">Activity</span> Measurements Experiments <span class="hlt">solar</span> vector magnetograph optical system is performed. Polarization aberration theory demonstrates that conventional telescope coating designs introduce unacceptably high levels of polarization aberrations into the optical system. Several ultralow polarization mirror and lens coatings designs for this instrument are discussed. Balancing of polarization aberrations at different surfaces is demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...820L..11J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...820L..11J"><span id="translatedtitle">The Magnetic Classification of <span class="hlt">Solar</span> <span class="hlt">Active</span> Regions 1992-2015</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaeggli, S. A.; Norton, A. A.</p> <p>2016-03-01</p> <p>The purpose of this Letter is to address a blindspot in our knowledge of <span class="hlt">solar</span> <span class="hlt">active</span> region (AR) statistics. To the best of our knowledge, there are no published results showing the variation of the Mount Wilson magnetic classifications as a function of <span class="hlt">solar</span> cycle based on modern observations. We show statistics for all ARs reported in the daily <span class="hlt">Solar</span> Region Summary from 1992 January 1 to 2015 December 31. We find that the α and β class ARs (including all sub-groups, e.g., βγ, βδ) make up fractions of approximately 20% and 80% of the sample, respectively. This fraction is relatively constant during high levels of <span class="hlt">activity</span> however, an increase in the α fraction to about 35% and and a decrease in the β fraction to about 65% can be seen near each <span class="hlt">solar</span> minimum and are statistically significant at the 2σ level. Over 30% of all ARs observed during the years of <span class="hlt">solar</span> maxima were appended with the classifications γ and/or δ, while these classifications account for only a fraction of a percent during the years near the <span class="hlt">solar</span> minima. This variation in the AR types indicates that the formation of complex ARs may be due to the pileup of frequent emergence of magnetic flux during <span class="hlt">solar</span> maximum, rather than the emergence of complex, monolithic flux structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990109083','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990109083"><span id="translatedtitle">The <span class="hlt">Influence</span> of Extremely Large <span class="hlt">Solar</span> Proton Events in a Changing Stratosphere. Stratospheric <span class="hlt">Influence</span> of <span class="hlt">Solar</span> Proton Events</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jackman, Charles H.; Fleming, Eric L.; Vitt, Francis M.</p> <p>1999-01-01</p> <p>Two periods of extremely large <span class="hlt">solar</span> proton events (SPEs) occurred in the past thirty years, which forced significant long-term polar stratospheric changes. The August 2-10, 1972 and October 19-27, 1989 SPEs happened in stratospheres that were quite different chemically. The stratospheric chlorine levels were relatively small in 1972 (approximately 1.2 ppbv) and were fairly substantial in 1989 at about (approximately 3 ppbv). Although these SPEs produced both HO(x) and NO(y) constituents in the mesosphere and stratosphere, only the NO(y) constituents had lifetimes long enough to affect ozone for several months to years past the events. Our recently improved two-dimensional chemistry and transport atmospheric model was used to compute the effects of these gigantic SPEs in a changing stratosphere. Significant upper stratospheric ozone depletions > 10% are computed to last for a few months past these SPEs. The long-lived SPE-produced NO(y) constituents were transported to lower levels during winter after these huge SPEs and caused impacts in the middle and lower stratosphere. During periods of high halogen loading these impacts resulted in interference with the chlorine and bromine loss cycles for ozone destruction. The chemical state of the atmosphere, including the stratospheric sulfate aerosol density, substantially affected the predicted stratospheric <span class="hlt">influence</span> of these extremely large SPEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900018869&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dphysical%2Bactivity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900018869&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dphysical%2Bactivity"><span id="translatedtitle">Physical mechanisms of <span class="hlt">solar</span> <span class="hlt">activity</span> effects in the middle atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ebel, A.</p> <p>1989-01-01</p> <p>A great variety of physical mechanisms of possibly <span class="hlt">solar</span> induced variations in the middle atmosphere has been discussed in the literature during the last decades. The views which have been put forward are often controversial in their physical consequences. The reason may be the complexity and non-linearity of the atmospheric response to comparatively weak forcing resulting from <span class="hlt">solar</span> <span class="hlt">activity</span>. Therefore this review focuses on aspects which seem to indicate nonlinear processes in the development of <span class="hlt">solar</span> induced variations. Results from observations and numerical simulations are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21067833','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21067833"><span id="translatedtitle">Microbial <span class="hlt">solar</span> cells: applying photosynthetic and electrochemically <span class="hlt">active</span> organisms.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Strik, David P B T B; Timmers, Ruud A; Helder, Marjolein; Steinbusch, Kirsten J J; Hamelers, Hubertus V M; Buisman, Cees J N</p> <p>2011-01-01</p> <p>Microbial <span class="hlt">solar</span> cells (MSCs) are recently developed technologies that utilize <span class="hlt">solar</span> energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest <span class="hlt">solar</span> energy, and use electrochemically <span class="hlt">active</span> microorganisms in the bioelectrochemical system to generate electrical current. Here, we review the principles and performance of various MSCs in an effort to identify the most promising systems, as well as the bottlenecks and potential solutions, for "real-life" MSC applications. We present an outlook on future applications based on the intrinsic advantages of MSCs, specifically highlighting how these living energy systems can facilitate the development of an electricity-producing green roof. PMID:21067833</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMED51B0423H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMED51B0423H"><span id="translatedtitle">Caught in the <span class="hlt">Solar</span> Wind: A Study of Space Weather and its <span class="hlt">Influence</span> on Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hill, R.; Chuckran, A.; Erickson, P. J.</p> <p>2007-12-01</p> <p>Space weather is a phenomenon that is becoming more familiar to the general public. As people are increasingly reliant on 21st century technology, the potential for disruption to their daily lives also rises. As the sun approaches its next <span class="hlt">solar</span> maximum in 2011 or 2012, the peak of Cycle 24 is expected to be the highest of the satellite age, perhaps surpassing that of Cycle 19 in 1957-58. In this teaching unit, we have attempted to create a series of lessons that sheds light on the concept of space weather and the sun's <span class="hlt">influences</span> on earth's magnetic field and upper atmosphere. Within this unit, we have provided ample opportunities for students to access and interpret real scientific data from a variety of sources. The main location is the web site www.spaceweather.com , which has near real time data from satellites such as SOHO, STEREO, ACE and POES. This data is easily viewed and explained within the site, and with appropriate instruction, students can regularly gather data, make predictions, and draw conclusions based on the current behavior of the sun. Examples include sunspot number and development, speed and density of <span class="hlt">solar</span> wind, orientation and strength of the interplanetary magnetic field, location of coronal holes, planetary K index and X-ray <span class="hlt">solar</span> flares. Depending on the level of the students, some or all of this data can be compiled over a period of time to better understand the behavior of the sun as well as its <span class="hlt">influence</span> on Earth. The goal of this unit is to provide a vehicle for students to understand how data is used by scientists. Once they have the base knowledge, students may be able to construct their own questions and follow through with research. An inquiry-based approach is incorporated whenever possible. With the onset of a potentially <span class="hlt">active</span> <span class="hlt">solar</span> cycle in the near future, teachers have the opportunity to make a dramatic connection between the natural world and their daily lives. <span class="hlt">Solar</span> storms can cause disruption to telephone communication</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1675S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1675S"><span id="translatedtitle">Investigation of relationships between parameters of <span class="hlt">solar</span> nano-flares and <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Safari, Hossein; Javaherian, Mohsen; Kaki, Bardia</p> <p>2016-07-01</p> <p><span class="hlt">Solar</span> flares are one of the important coronal events which are originated in <span class="hlt">solar</span> magnetic <span class="hlt">activity</span>. They release lots of energy during the interstellar medium, right after the trigger. Flare prediction can play main role in avoiding eventual damages on the Earth. Here, to interpret <span class="hlt">solar</span> large-scale events (e.g., flares), we investigate relationships between small-scale events (nano-flares) and large-scale events (e.g., flares). In our method, by using simulations of nano-flares based on Monte Carlo method, the intensity time series of nano-flares are simulated. Then, the <span class="hlt">solar</span> full disk images taken at 171 angstrom recorded by SDO/AIA are employed. Some parts of the <span class="hlt">solar</span> disk (quiet Sun (QS), coronal holes (CHs), and <span class="hlt">active</span> regions (ARs)) are cropped and the time series of these regions are extracted. To compare the simulated intensity time series of nano-flares with the intensity time series of real data extracted from different parts of the Sun, the artificial neural networks is employed. Therefore, we are able to extract physical parameters of nano-flares like both kick and decay rate lifetime, and the power of their power-law distributions. The procedure of variations in the power value of power-law distributions within QS, CH is similar to AR. Thus, by observing the small part of the Sun, we can follow the procedure of <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRA..117.8335L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRA..117.8335L"><span id="translatedtitle"><span class="hlt">Influence</span> of interplanetary <span class="hlt">solar</span> wind sector polarity on the ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Jing; Liu, Libo; Zhao, Biqiang; Wan, Weixing</p> <p>2012-08-01</p> <p>Knowledge of <span class="hlt">solar</span> sector polarity effects on the ionosphere may provide some clues in understanding of the ionospheric day-to-day variability and "hysteresis" effect on foF2. Ionospheric response to changes in <span class="hlt">solar</span> sector polarity has not been fully documented previously, partly due to the limitation of observations. In this study, a <span class="hlt">solar</span>-terrestrial connection ranging from <span class="hlt">solar</span> sector boundary (SB) crossings, geomagnetic disturbances and ionospheric perturbations has been demonstrated. The increases in interplanetary <span class="hlt">solar</span> wind speed within three days are seen after SB crossings, while the decreases in <span class="hlt">solar</span> wind dynamic pressure and magnetic field intensity immediately after SB crossings are confirmed by the superposed epoch analysis results. Furthermore, the interplanetary magnetic field (IMF) Bz component turns from northward to southward in March equinox and June solstice as the Earth passes from a <span class="hlt">solar</span> sector of outward to inward directed magnetic fields, whereas the reverse situation occurs for the transition from toward to away sectors. The IMF Bz component for the same <span class="hlt">solar</span> sector polarity has opposite signs between March equinox and September equinox, and also between June solstice and December solstice. In order to know how the ionosphere reacts to the interplanetary <span class="hlt">solar</span> wind variations linkage of SB crossings, the F2 region critical frequency (foF2) covering about four <span class="hlt">solar</span> cycles and total electron content (TEC) during 1998-2011 are utilized to extract the related information, revealing that they are not modified significantly and vary within the range of ±15% on average. The responses of the ionospheric TEC to SB crossings exhibit complex temporal and spatial variations and have strong dependencies on season, latitude, and <span class="hlt">solar</span> cycle. This effect is more appreciable in equinoctial months than in solstitial months, which is mainly caused by larger southwardBzcomponents in equinox. In September equinox, latitudinal profile of relative</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090017773','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090017773"><span id="translatedtitle">Evidence for <span class="hlt">Solar</span> Cycle <span class="hlt">Influence</span> on the Infrared Energy Budget and Radiative Cooling of the Thermosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.</p> <p>2007-01-01</p> <p>We present direct observational evidence for <span class="hlt">solar</span> cycle <span class="hlt">influence</span> on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 <span class="hlt">solar</span> index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between <span class="hlt">solar</span> <span class="hlt">activity</span> and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM31C2511M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM31C2511M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> wind <span class="hlt">influence</span> on the Jovian inner magnetosphere observed by Hisaki/EXCEED</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murakami, G.; Yoshioka, K.; Yamazaki, A.; Tsuchiya, F.; Kimura, T.; Tao, C.; Kagitani, M.; Sakanoi, T.; Uemizu, K.; Kasaba, Y.; Yoshikawa, I.; Fujimoto, M.</p> <p>2015-12-01</p> <p>The dawn-dusk asymmetry of the Io plasma torus has been seen by several observations [e.g., Sandel and Broadfoot, 1982; Steffl et al., 2004]. Ip and Goertz [1983] explained this asymmetry can be caused by a dawn-to-dusk electric field in the Jupiter's inner magnetosphere. However, the question what physical process can impose such an electric field deep inside the strong magnetosphere still remains. The long-term monitoring of the Io plasma torus is a key observation to answer this question. The extreme ultraviolet (EUV) spectrometer EXCEED onboard the Hisaki satellite observed the Io plasma torus continuously during the two periods: from December 2013 to March 2014 and from November 2014 to May 2015. We found clear responses of the dawn-dusk asymmetry to rapid increases of the <span class="hlt">solar</span> wind dynamic pressure. We statistically analyzed the relations between <span class="hlt">solar</span> wind and IPT response. Furthermore, we investigated the <span class="hlt">influence</span> of Io's volcanic <span class="hlt">activity</span>, detected by Hisaki in January 2015, on the <span class="hlt">solar</span> wind response of Jovian inner magnetosphere. We will report the initial results of this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17677760','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17677760"><span id="translatedtitle">Self-similar signature of the <span class="hlt">active</span> <span class="hlt">solar</span> corona within the inertial range of <span class="hlt">solar</span>-wind turbulence.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kiyani, K; Chapman, S C; Hnat, B; Nicol, R M</p> <p>2007-05-25</p> <p>We quantify the scaling of magnetic energy density in the inertial range of <span class="hlt">solar</span>-wind turbulence seen in situ at 1 AU with respect to <span class="hlt">solar</span> <span class="hlt">activity</span>. At <span class="hlt">solar</span> maximum, when the coronal magnetic field is dynamic and topologically complex, we find self-similar scaling in the <span class="hlt">solar</span> wind, whereas at <span class="hlt">solar</span> minimum, when the coronal fields are more ordered, we find multifractality. This quantifies the <span class="hlt">solar</span>-wind signature that is of direct coronal origin and distinguishes it from that of local MHD turbulence, with quantitative implications for coronal heating of the <span class="hlt">solar</span> wind. PMID:17677760</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980202344','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980202344"><span id="translatedtitle"><span class="hlt">Influence</span> of Short-Term <span class="hlt">Solar</span> UV Variability on the Determination of <span class="hlt">Solar</span> Cycle Minimum</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cebula, Richard P.; DeLand, Matthew T.</p> <p>1997-01-01</p> <p>Smoothing <span class="hlt">solar</span> UV data on rotational timescale (approx. 27 days) improves identification of <span class="hlt">solar</span> minimum. Smoothing intervals which are not multiples of rotational period (e.g. 35 days) can leave measurable residual signal. No evidence found for periodic behavior on intermediate (50-250 days) time scales during Cycle 22, based on data from three <span class="hlt">solar</span> UV instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760007440','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760007440"><span id="translatedtitle">Possible relationships between <span class="hlt">solar</span> <span class="hlt">activity</span> and meteorological phenomena</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bandeen, W. R. (Editor); Maran, S. P. (Editor)</p> <p>1975-01-01</p> <p>A symposium was conducted in which the following questions were discussed: (1) the evidence concerning possible relationships between <span class="hlt">solar</span> <span class="hlt">activity</span> and meteorological phenomena; (2) plausible physical mechanisms to explain these relationships; and (3) kinds of critical measurements needed to determine the nature of <span class="hlt">solar</span>/meteorological relationships and/or the mechanisms to explain them, and which of these measurements can be accomplished best from space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830012579&hterms=activity+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dactivity%2Btheory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830012579&hterms=activity+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dactivity%2Btheory"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span>: The Sun as an X-ray star</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Golub, L.</p> <p>1981-01-01</p> <p>The existence and constant <span class="hlt">activity</span> of the Sun's outer atmosphere are thought to be due to the continual emergence of magnetic fields from the <span class="hlt">Solar</span> interior and the stressing of these fields at or near the surface layers of the Sun. The structure and <span class="hlt">activity</span> of the corona are thus symptomatic of the underlying magnetic dynamo and the existence of an outer turbulent convective zone on the Sun. A sufficient condition for the existence of coronal <span class="hlt">activity</span> on other stars would be the existence of a magnetic dynamo and an outer convective zone. The theoretical relationship between magnetic fields and coronal <span class="hlt">activity</span> can be tested by <span class="hlt">Solar</span> observations, for which the individual loop structures can be resolved. A number of parameters however, which enter into the alternative theoretical formulations remain fixed in all <span class="hlt">Solar</span> observations. To determine whether these are truly parameters of the theory observations need to be extended to nearby stars on which suitable conditions may occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993GeoRL..20.2271O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993GeoRL..20.2271O"><span id="translatedtitle">Semiannual variation of the geomagnetic <span class="hlt">activity</span> and <span class="hlt">solar</span> wind parameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Orlando, M.; Moreno, G.; Parisi, M.; Storini, M.</p> <p>1993-10-01</p> <p>The semiannual variation of the geomagnetic <span class="hlt">activity</span> is investigated in connection with a large set of <span class="hlt">solar</span> wind and interplanetary magnetic field data (4494 daily averages from 1965 to 1987). Our analysis confirms that the geomagnetic <span class="hlt">activity</span> (described by the aa index), is mainly modulated by the southward component of the magnetic field (BS), as suggested by Russell and McPherron. On the other hand, it is also found that the <span class="hlt">solar</span> wind velocity (V) has a relevant role in this phenomenon. In fact, the amplitude of the aa modulation is best correlated with the function BSV2. We also explore the linkage between the annual trend of aa and the sunspot <span class="hlt">activity</span> (1868-1989), showing that the modulation of the geomagnetic <span class="hlt">activity</span> follows a more regular pattern during the descending phase of the <span class="hlt">solar</span> cycle than during the rising and maximum parts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUSM.B32A..18D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUSM.B32A..18D"><span id="translatedtitle">Relation Between Myocardial Infarction Deaths and <span class="hlt">Solar</span> <span class="hlt">Activity</span> in Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diaz-Sandoval, R.</p> <p>2002-05-01</p> <p>We study the daily incidence of myocardial infarction deaths in Mexico for 4 years (1996-99) with a total of 129 917 cases in all the country, collected at the General Directorate of Epidemiology (National Ministry of Health). We divided the cases by sex and age and perform two kinds of analysis. First, we did an spectral analysis using the Maximum Entropy Method, considering the complete period, and minimum and maximum epochs of <span class="hlt">solar</span> <span class="hlt">activity</span>. The results show that the most persistent periodicity at higher frequencies in the myocardial infarction death occurrence is that of seven days. Considering the <span class="hlt">solar</span> cycle phases, we found that during <span class="hlt">solar</span> minimum times some frequencies are not detectable compared with <span class="hlt">solar</span> maximum epochs, particularly that of seven days. Biological rhythms close to seven days, the circaseptans, are in general thought to be only the result of the social organization of life. However, this cannot be the only explanation, because the 7-days periodicity has been encountered in lower organisms not related with our rhythms of life. Thus, it has been proposed that biological rhythms could be evolutionary adaptations to environmental conditions, particularly, <span class="hlt">solar</span> <span class="hlt">activity</span>. In the second analysis we compared two <span class="hlt">solar</span> <span class="hlt">activity</span>-related phenomena: the Forbush decreases of cosmic rays and the geomagnetic index Ap for various levels of geomagnetic perturbations. The results show that during decreases of cosmic ray fluxes, for most cases there is a higher average myocardial infarction deaths occurrence, compared with the average incidence in days of no decreases. For geomagnetic <span class="hlt">activity</span> we find the same situation in most cases. Furthermore, this behavior is more pronounced as the level of the perturbation increases and in times of maximum <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001ICRC....8.3359A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001ICRC....8.3359A"><span id="translatedtitle">Forecast for <span class="hlt">solar</span> cycle 23 <span class="hlt">activity</span>: a progress report</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahluwalia, H. S.</p> <p>2001-08-01</p> <p>At the 25th International Cosmic Ray Conference (ICRC) at Durban, South Africa, I announced the discovery of a three cycle quasi-periodicity in the ion chamber data string assembled by me, for the 1937 to 1994 period (Conf. Pap., v. 2, p. 109, 1997). It corresponded in time with a similar quasi-periodicity observed in the dataset for the planetary index Ap. At the 26th ICRC at Salt Lake City, UT, I reported on our analysis of the Ap data to forecast the amplitude of <span class="hlt">solar</span> cycle 23 <span class="hlt">activity</span> (Conf. Pap., v. 2, pl. 260, 1999). I predicted that cycle 23 will be moderate (a la cycle 17), notwithstanding the early exuberant forecasts of some <span class="hlt">solar</span> astronomers that cycle 23, "may be one of the greatest cycles in recent times, if not the greatest." Sunspot number data up to April 2001 indicate that our forecast appears to be right on the mark. We review the <span class="hlt">solar</span>, interplanetary and geophysical data and describe the important lessons learned from this experience. 1. Introduction Ohl (1971) was the first to realize that Sun may be sending us a subliminal message as to its intent for its <span class="hlt">activity</span> (Sunspot Numbers, SSN) in the next cycle. He posited that the message was embedded in the geomagnetic <span class="hlt">activity</span> (given by sum Kp). Schatten at al (1978) suggested that Ohl hypothesis could be understood on the basis of the model proposed by Babcock (1961) who suggested that the high latitude <span class="hlt">solar</span> poloidal fields, near a minimum, emerge as the toroidal fields on opposite sides of the <span class="hlt">solar</span> equator. This is known as the <span class="hlt">Solar</span> Dynamo Model. One can speculate that the precursor poloidal <span class="hlt">solar</span> field is entrained in the high speed <span class="hlt">solar</span> wind streams (HSSWS) from the coronal holes which are observed at Earth's orbit during the descending phase of the previous cycle. The interaction</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...768..162P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...768..162P"><span id="translatedtitle"><span class="hlt">Solar</span> Magnetic <span class="hlt">Activity</span> Cycles, Coronal Potential Field Models and Eruption Rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petrie, G. J. D.</p> <p>2013-05-01</p> <p>We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 <span class="hlt">solar</span> <span class="hlt">activity</span> cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National <span class="hlt">Solar</span> Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox <span class="hlt">Solar</span> Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with <span class="hlt">active</span> fields over most of the period studied, except between 2003 and 2006 when the <span class="hlt">active</span> fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the <span class="hlt">activity</span> cycle. All non-axisymmetric multipole strengths are well correlated with the <span class="hlt">activity</span> cycle. The tilt of the <span class="hlt">solar</span> dipole is therefore almost entirely due to <span class="hlt">active</span>-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This <span class="hlt">influence</span> of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, <span class="hlt">Solar</span> Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of <span class="hlt">solar</span> eruptions is found to be systematically higher for <span class="hlt">active</span> years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NewA...15..561B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NewA...15..561B"><span id="translatedtitle">North-south asymmetry of different <span class="hlt">solar</span> <span class="hlt">activity</span> features during <span class="hlt">solar</span> cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bankoti, Neeraj Singh; Joshi, Navin Chandra; Pande, Seema; Pande, Bimal; Pandey, Kavita</p> <p>2010-08-01</p> <p>A study on north-south (N-S) asymmetry of different <span class="hlt">solar</span> <span class="hlt">activity</span> features (DSAF) such as <span class="hlt">solar</span> proton events, <span class="hlt">solar</span> <span class="hlt">active</span> prominences [total, low (⩽40°) and high (⩾50°) latitudes], H α flare indices, soft X-ray flares, monthly mean sunspot areas and monthly mean sunspot numbers carried out from May 1996 to October 2008. Study shows a southern dominance of DSAF during this period. During the rising phase of the cycle 23 the number of DSAF approximately equals on both, the northern and the southern hemispheres. But these <span class="hlt">activities</span> tend to shift from northern to southern hemisphere during the period 1998-1999. The statistical significance of the asymmetry time series using a χ2-test of goodness of fit indicates that in most of the cases the asymmetry is highly significant, meaning thereby that the asymmetry is a real feature in the N-S distribution of DSAF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910054026&hterms=kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dkuhn','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910054026&hterms=kuhn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dkuhn"><span id="translatedtitle">Short-term changes in <span class="hlt">solar</span> oscillation frequencies and <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woodard, M. F.; Libbrecht, K. G.; Kuhn, J. R.; Murray, N.</p> <p>1991-01-01</p> <p>It is shown that the frequencies of <span class="hlt">solar</span> rho-mode oscillations change significantly over periods as short as one month. These changes correlate significantly with variations in the strength of surface <span class="hlt">solar</span> <span class="hlt">activity</span> as measured by the average, over the sun's visible surface, of the magnitude of the line-of-sight magnetic field component from magnetograms. The frequency and mean magnetic variations are found to obey a linear relationship. It is seen that the mean frequency shift at any time depends on the history of <span class="hlt">solar</span> <span class="hlt">activity</span> over an interval of, at most, several months prior to the measurement and conclude that the dominant mechanism of the frequency shift is correlated with surface magnetic <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21313772','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21313772"><span id="translatedtitle">IS THE CURRENT LACK OF <span class="hlt">SOLAR</span> <span class="hlt">ACTIVITY</span> ONLY SKIN DEEP?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Broomhall, A.-M.; Chaplin, W. J.; Elsworth, Y.; Fletcher, S. T.; New, R. E-mail: wjc@bison.ph.bham.ac.uk E-mail: S.Fletcher@shu.ac.uk</p> <p>2009-08-01</p> <p>The Sun is a variable star whose magnetic <span class="hlt">activity</span> and total irradiance vary on a timescale of approximately 11 years. The current <span class="hlt">activity</span> minimum has attracted considerable interest because of its unusual duration and depth. This raises the question: what might be happening beneath the surface where the magnetic <span class="hlt">activity</span> ultimately originates? The surface <span class="hlt">activity</span> can be linked to the conditions in the <span class="hlt">solar</span> interior by the observation and analysis of the frequencies of the Sun's natural seismic modes of oscillation-the p modes. These seismic frequencies respond to changes in <span class="hlt">activity</span> and are probes of conditions within the Sun. The Birmingham <span class="hlt">Solar</span>-Oscillations Network (BiSON) has made measurements of p-mode frequencies over the last three <span class="hlt">solar</span> <span class="hlt">activity</span> cycles, and so is in a unique position to explore the current unusual and extended <span class="hlt">solar</span> minimum. We show that the BiSON data reveal significant variations of the p-mode frequencies during the current minimum. This is in marked contrast to the surface <span class="hlt">activity</span> observations, which show little variation over the same period. The level of the minimum is significantly deeper in the p-mode frequencies than in the surface observations. We observe a quasi-biennial signal in the p-mode frequencies, which has not previously been observed at mid- and low-<span class="hlt">activity</span> levels. The stark differences in the behavior of the frequencies and the surface <span class="hlt">activity</span> measures point to <span class="hlt">activity</span>-related processes occurring in the <span class="hlt">solar</span> interior, which are yet to reach the surface, where they may be attenuated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9902C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9902C"><span id="translatedtitle">Testing the potential of 10Be in varved sediments from two lakes for <span class="hlt">solar</span> <span class="hlt">activity</span> reconstruction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czymzik, Markus; Muscheler, Raimund; Brauer, Achim; Adolphi, Florian; Ott, Florian; Kienel, Ulrike; Dräger, Nadine; Slowinski, Michal; Aldahan, Ala; Possnert, Göran</p> <p>2015-04-01</p> <p>The potential of 10Be in annually laminated (varved) lake sediments for <span class="hlt">solar</span> <span class="hlt">activity</span> reconstruction is, to date, largely unexplored. It is hypothesized that 10Be contents in sediments from well-chosen lakes reflect the <span class="hlt">solar</span> induced atmospheric production signal. The varved nature of these archives provides the chance to establish <span class="hlt">solar</span> <span class="hlt">activity</span> time-series with very high temporal precision. However, so far <span class="hlt">solar</span> <span class="hlt">activity</span> reconstruction from 10Be in varved lake sediments is hampered due to a lack of detailed knowledge of the process chain from production in the atmosphere to deposition on the lake floor. Calibrating 10Be time-series from varved lake sediments against complementary proxy records from the same sediment archive as well as instrumental meteorological and <span class="hlt">solar</span> <span class="hlt">activity</span> data will allow a process-based understanding of 10Be deposition in these lakes and a quantitative evaluation of their potential for <span class="hlt">solar</span> <span class="hlt">activity</span> reconstruction. 10Be concentration and flux time-series at annual resolution were constructed for the period 1983 to 2007 (approx. <span class="hlt">solar</span> cycles 22 and 23) conducting accelerator mass spectrometry and varve chronology on varved sediments of Lakes Tiefer See and Czechowski, located on an east-west transect at a distance of about 450 km in the lowlands of northern-central Europe. 10Be concentrations vary between 0.9 and 1.8*108atoms/g, with a mean of 1.3*108atoms/g in Lake Tiefer See and between 0.6 and 1.6*108atoms/g, with a mean of 1*108atoms/g in Lake Czechowski. Calculated mean 10Be flux is 2.3*108atoms/cm2/year for Lake Tiefer See and 0.7*108atoms/cm2/year for Lake Czechowski. Calibrating the 10Be time-series against corresponding geochemical μ-XRF profiles, varve thickness and total organic carbon records as well as precipitation data from the nearby stations Schwerin for Lake Tiefer See and Koscierzyna for Lake Czechowski and a neutron monitor record of <span class="hlt">solar</span> <span class="hlt">activity</span> suggests (1) a complex interaction of varying processes <span class="hlt">influencing</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JAP...104i4507W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JAP...104i4507W"><span id="translatedtitle"><span class="hlt">Influence</span> of base pressure and atmospheric contaminants on a-Si:H <span class="hlt">solar</span> cell properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woerdenweber, J.; Merdzhanova, T.; Schmitz, R.; Mück, A.; Zastrow, U.; Niessen, L.; Gordijn, A.; Carius, R.; Beyer, W.; Stiebig, H.; Rau, U.</p> <p>2008-11-01</p> <p>The <span class="hlt">influence</span> of atmospheric contaminants oxygen and nitrogen on the performance of thin-film hydrogenated amorphous silicon (a-Si:H) <span class="hlt">solar</span> cells grown by plasma-enhanced chemical vapor deposition at 13.56 MHz was systematically investigated. The question is addressed as to what degree of high base pressures (up to 10-4 Torr) are compatible with the preparation of good quality amorphous silicon based <span class="hlt">solar</span> cells. The data show that for the intrinsic a-Si:H absorber layer exists critical oxygen and nitrogen contamination levels (about 2×1019 atoms/cm3 and 4×1018 atoms/cm3, respectively). These levels define the minimum impurity concentration that causes a deterioration in <span class="hlt">solar</span> cell performance. This critical concentration is found to depend little on the applied deposition regime. By enhancing, for example, the flow of process gases, a higher base pressure (and leak rate) can be tolerated before reaching the critical contamination level. The electrical properties of the corresponding films show that increasing oxygen and nitrogen contamination results in an increase in dark conductivity and photoconductivity, while <span class="hlt">activation</span> energy and photosensitivity are decreased. These effects are attributed to nitrogen and oxygen induced donor states, which cause a shift of the Fermi level toward the conduction band and presumably deteriorate the built-in electric field in the <span class="hlt">solar</span> cells. Higher doping efficiencies are observed for nitrogen compared to oxygen. Alloying effects (formation of SiOx) are observed for oxygen contaminations above 1020 atoms/cm3, leading to an increase in the band gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21185903','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21185903"><span id="translatedtitle"><span class="hlt">Influence</span> of base pressure and atmospheric contaminants on a-Si:H <span class="hlt">solar</span> cell properties</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Woerdenweber, J.; Schmitz, R.; Mueck, A.; Zastrow, U.; Niessen, L.; Gordijn, A.; Carius, R.; Beyer, W.; Rau, U.; Merdzhanova, T.; Stiebig, H.</p> <p>2008-11-01</p> <p>The <span class="hlt">influence</span> of atmospheric contaminants oxygen and nitrogen on the performance of thin-film hydrogenated amorphous silicon (a-Si:H) <span class="hlt">solar</span> cells grown by plasma-enhanced chemical vapor deposition at 13.56 MHz was systematically investigated. The question is addressed as to what degree of high base pressures (up to 10{sup -4} Torr) are compatible with the preparation of good quality amorphous silicon based <span class="hlt">solar</span> cells. The data show that for the intrinsic a-Si:H absorber layer exists critical oxygen and nitrogen contamination levels (about 2x10{sup 19} atoms/cm{sup 3} and 4x10{sup 18} atoms/cm{sup 3}, respectively). These levels define the minimum impurity concentration that causes a deterioration in <span class="hlt">solar</span> cell performance. This critical concentration is found to depend little on the applied deposition regime. By enhancing, for example, the flow of process gases, a higher base pressure (and leak rate) can be tolerated before reaching the critical contamination level. The electrical properties of the corresponding films show that increasing oxygen and nitrogen contamination results in an increase in dark conductivity and photoconductivity, while <span class="hlt">activation</span> energy and photosensitivity are decreased. These effects are attributed to nitrogen and oxygen induced donor states, which cause a shift of the Fermi level toward the conduction band and presumably deteriorate the built-in electric field in the <span class="hlt">solar</span> cells. Higher doping efficiencies are observed for nitrogen compared to oxygen. Alloying effects (formation of SiO{sub x}) are observed for oxygen contaminations above 10{sup 20} atoms/cm{sup 3}, leading to an increase in the band gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990JGG....42..825K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990JGG....42..825K"><span id="translatedtitle">Correlation of nighttime MF signal strength with <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kohata, Hiroki; Kimura, Iwane; Wakai, Noboru; Ogawa, Tadahiko</p> <p></p> <p>Observations of the signal strength of MF broadcasting signals (774/770 kHz) transmitted from Akita, Japan, on board the Japanese Antarctic ice breaker Fuji, bound from Japan to Syowa station, Antarctica, have revealed an interesting positive correlation between strengths of long distance signals propagating at night and <span class="hlt">solar</span> <span class="hlt">activity</span>. It is already known that MF propagation characteristics in North America show a negative correlation with <span class="hlt">solar</span> <span class="hlt">activity</span>. The present paper, interprets the results by using the multihop method with full-wave analysis. The difference in correlation with <span class="hlt">solar</span> <span class="hlt">activity</span> between the results of Fuji and those in North America can be elucidated if it is assumed that there is a ledge in the electron-density profile around an altitude range of 85 to 90 km and that the density of the ledge is smaller in the North American region than in the equatorial region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JGR...104.6871C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JGR...104.6871C"><span id="translatedtitle">A prediction of geomagnetic <span class="hlt">activity</span> for <span class="hlt">solar</span> cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cliver, E. W.; Ling, A. G.; Wise, J. E.; Lanzerotti, L. J.</p> <p>1999-04-01</p> <p>Using a database of 13 <span class="hlt">solar</span> cycles of geomagnetic aa data, we obtained correlations between cycle averages of geomagnetic <span class="hlt">activity</span> (and sunspot number) and the numbers of days with disturbance levels above certain aa thresholds. We then used a precursor-type relation to predict an average aa index of 23.1 nT for cycle 23 and inserted this average aa value into the above correlations to forecast the integral size distribution of geomagnetic <span class="hlt">activity</span> for the new cycle. The predicted size distribution is similar to that observed for cycles 21 and 22 but most closely resembles that of <span class="hlt">solar</span> cycle 18 (1944-1954), which was slightly smaller than cycles 21 and 22. Our prediction agrees reasonably well with the ``climatology-based'' forecast made by the intergovernmental panel tasked to predict geomagnetic <span class="hlt">activity</span> for the coming <span class="hlt">solar</span> cycle and is significantly different from their ``precursor-based'' prediction.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AdSpR..33..959P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AdSpR..33..959P"><span id="translatedtitle">Topside electron temperature models for low and high <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pandey, V. K.; Sethi, N. K.; Mahajan, K. K.</p> <p></p> <p>It is now well known that in the topside ionosphere thermal conduction from the protonosphere becomes the dominant factor over the heating and loss terms in shaping the ionospheric electron temperature (Te) profile. By analyzing a limited database of incoherent scatter (IS) Te measurements, Mahajan and Pandey [J. Geophys. Res. 85 (1980) 213] reported a correlation between the electron heat flux and electron density in the topside ionosphere. Since attention has been steadily mounting for the empirical modeling of Te, we now exploit the large database of IS measurements of Te and Ne at Arecibo during 1989-1990 (high <span class="hlt">solar</span> <span class="hlt">activity</span>), as well as during 1975-1976 (low <span class="hlt">solar</span> <span class="hlt">activity</span>) for this purpose. We again find a functional relationship between heat flux and electron density in the topside ionosphere during both the <span class="hlt">solar</span> <span class="hlt">activities</span>. These functional relationships are used to generate topside Te profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1983STIN...8421484R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1983STIN...8421484R&link_type=ABSTRACT"><span id="translatedtitle">Summary of <span class="hlt">solar</span> <span class="hlt">activity</span> observed in the Mauna Loa <span class="hlt">Solar</span> Observatory, 1980 - 1983</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rock, K.; Fisher, R.; Garcia, C.; Yasukawa, E.</p> <p>1983-11-01</p> <p>The following technical note summarizes <span class="hlt">solar</span> <span class="hlt">activity</span> observed during the first four years operation of the experiment systems of the Coronal Dynamics Project, which are located at the Mauna Loa <span class="hlt">Solar</span> Observatory. This short report has been produced with the general aim of providing users of Mauna Loa observations with a summary of data for specific events. So that this table might be as useful as possible, a comprehensive review of three sources was performed. The plain language logs, identified as the so-called observer's logs, the now-discontinued <span class="hlt">activity</span> logs, and the prominence monitor quality control logs were the sources from which the information in the following tables was obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16512547','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16512547"><span id="translatedtitle"><span class="hlt">Influence</span> of crystal tilt on <span class="hlt">solar</span> irradiance of cirrus clouds.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klotzsche, Susann; Macke, Andreas</p> <p>2006-02-10</p> <p>The single and multiple scattering and absorption properties of hexagonal ice columns with different degrees of particle orientation are modeled in the <span class="hlt">solar</span> spectral range by means of a ray-tracing single-scattering code and a Monte Carlo radiative-transfer code. The scattering properties are most sensitive to particle orientation for the <span class="hlt">solar</span> zenith angles of 50 degrees (asymmetry parameter) and 90 degrees (single-scattering albedo). Provided that the ice columns are horizontally oriented, the usual assumption of random orientation leads to an overestimation (underestimation) of the reflected (transmitted) <span class="hlt">solar</span> broadband radiation at high Sun elevation and to an underestimation (overestimation) at medium <span class="hlt">solar</span> zenith angles. The orientation effect is more (less) pronounced in scattering and transmission (absorption) for smaller ice crystals. PMID:16512547</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790004819','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790004819"><span id="translatedtitle">Effects of long-period <span class="hlt">solar</span> <span class="hlt">activity</span> fluctuation on temperature and pressure of the terrestrial atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubashev, B. M.</p> <p>1978-01-01</p> <p>The present state of research on the <span class="hlt">influence</span> of <span class="hlt">solar</span> sunspot <span class="hlt">activity</span> on tropospheric temperature and pressure is reviewed. The existence of an 11-year temperature cycle of 5 different types is affirmed. A cyclic change in atmospheric pressure, deducing characteristic changes between 11-year cycles is discussed. The existence of 80-year and 5-to-6-year cycles of temperature is established, and physical causes for birth are suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ATsir1585....1V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ATsir1585....1V"><span id="translatedtitle"><span class="hlt">Solar</span> Wind and Magnetic Storms in 24-th Cycle of <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Val'chuk, T. E.</p> <p>2013-01-01</p> <p>Slow growth of 24-th <span class="hlt">solar</span> cycle allows adding of this cycle to the type of low cycles. Geomagnetic <span class="hlt">activity</span> is not expensive too - strong geomagnetic storms were absent in the beginning of growth branch of this cycle. Very prolonged minimum was lasting about 4 years. We may remember that century minimum of <span class="hlt">solar</span> <span class="hlt">activity</span> was proposed after XX century high strong cycles. It may be - we look this situation now in 2012. Our work is connected with sporadic phenomena in 24-th cycle. These more or less intensive variations of <span class="hlt">solar</span> <span class="hlt">activity</span> are not predicted, they are caused by flowing up of new magnetic fields of spots, the excitement of flares, intensive plasma flows, coronal mass ejections (CME) and filament eruptions. Now two last versions (CME and filaments) are primary. Geomagnetic <span class="hlt">activity</span> on a descending phase of <span class="hlt">solar</span> cycle depends on quality of coronal holes providing the recurrent geomagnetic storms. Sporadic phenomena, which generated geomagnetic storms in Earth magnetosphere if flare flows reached the Earth magnetosphere and transferred it the energy are more interesting for us - they are the valuable characteristics of 24-th cycle. The disturbed period of several geomagnetic storms was generated by <span class="hlt">solar</span> <span class="hlt">active</span> region N11429. It is one sample only, this case is difficult and indicative. Replacing each other scenarios describe geomagnetic variations at the beginning of March 2012. Detailed consideration of this interval revealed its communication with sporadic events on the Sun. The structural configuration of plasma in flare flows was defined by means fractal dimension calculations of <span class="hlt">solar</span> plasma parameters: velocity Vx and density N in flare streams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AAS...201.8812W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AAS...201.8812W"><span id="translatedtitle">More <span class="hlt">Solar</span> <span class="hlt">Activities</span> for Astro 101</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>West, M. L.</p> <p>2002-12-01</p> <p>For many astronomy students the sun is not only the brightest astronomical object they can observe but also the most interesting since it has an immediate effect on their daily lives. Students enjoy analyzing their own observations using a Sunspotter, or images from archives such as the RBSE CD-ROM (1999, 2000, T. Rector), or current images found on the Internet. They can measure each sunspot's latitude, longitude, and approximate surface area by transparent Stonyhurst grids and fine graph paper, or NIH Image or Scion Image tools. Graphing latitude vs. time shows its near constancy. Longitude increases linearly with time and allows a measure of the sun's rotation period. Area vs. time increases for some spot groups, decreases for others, and fades but revives for others. This behavior elicits a lot of questions, hypotheses, and plans for more observations. The variation of <span class="hlt">solar</span> rotation period with latitude can be tested. Does the sun's rotation period change with month and year also? One of the oldest calendar markers is the sun's altitude at local noon. It can be measured easily with a paper scale attached to the cradle of a Sunspotter. Noticing the civil time at local noon allows one to understand the analemma. What do sunspots correlate with? Students have investigated the correlation of sunspot numbers or areas with radio bursts, visible light or x-ray flares, <span class="hlt">solar</span> wind speed, density, or magnetic field, aurorae, geomagnetic storms, the Earth's ozone layer, aircraft flight safety, ultraviolet light, global average temperature, local daily temperature variations, power grid outages, disruptions of Earth orbiting satellites or interplanetary spacecraft, earthquakes, hurricanes, tornadoes, or other natural disasters,</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1260986-multi-scale-statistical-analysis-coronal-solar-activity','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1260986-multi-scale-statistical-analysis-coronal-solar-activity"><span id="translatedtitle">Multi-scale statistical analysis of coronal <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Gamborino, Diana; del-Castillo-Negrete, Diego; Martinell, Julio J.</p> <p>2016-07-08</p> <p>Multi-filter images from the <span class="hlt">solar</span> corona are used to obtain temperature maps that are analyzed using techniques based on proper orthogonal decomposition (POD) in order to extract dynamical and structural information at various scales. Exploring <span class="hlt">active</span> regions before and after a <span class="hlt">solar</span> flare and comparing them with quiet regions, we show that the multi-scale behavior presents distinct statistical properties for each case that can be used to characterize the level of <span class="hlt">activity</span> in a region. Information about the nature of heat transport is also to be extracted from the analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PASJ...64...86P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PASJ...64...86P"><span id="translatedtitle">Variation of Meteor Heights and <span class="hlt">Solar</span>-Cycle <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Porubcan, Vladimír; Bucek, Marek; Cevolani, Giordano; Zigo, Pavel</p> <p>2012-08-01</p> <p>Photographic meteor observations of the Perseid meteoroid stream compiled from the IAU Meteor Data Center catalogue are analyzed from the viewpoint of possible long-term variation of meteor heights with the <span class="hlt">solar</span>-cycle <span class="hlt">activity</span>, which was previously reported from radio observations. The observed beginning and end-point heights of the Perseids, normalized for the geocentric velocity and the absolute photographic magnitude, do not show a variation consistent with the <span class="hlt">solar</span>-cycle <span class="hlt">activity</span>. This result is valid for the mass range of larger meteoroids observed by photographic techniques, and must be still verified also for the range of smaller meteoroids observed by TV and radio methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NPGeo..23..175G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NPGeo..23..175G"><span id="translatedtitle">Multi-scale statistical analysis of coronal <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gamborino, Diana; del-Castillo-Negrete, Diego; Martinell, Julio J.</p> <p>2016-07-01</p> <p>Multi-filter images from the <span class="hlt">solar</span> corona are used to obtain temperature maps that are analyzed using techniques based on proper orthogonal decomposition (POD) in order to extract dynamical and structural information at various scales. Exploring <span class="hlt">active</span> regions before and after a <span class="hlt">solar</span> flare and comparing them with quiet regions, we show that the multi-scale behavior presents distinct statistical properties for each case that can be used to characterize the level of <span class="hlt">activity</span> in a region. Information about the nature of heat transport is also to be extracted from the analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JASTP..67..595G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JASTP..67..595G"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> forecast: Spectral analysis and neurofuzzy prediction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gholipour, Ali; Lucas, Caro; Araabi, Babak N.; Shafiee, Masoud</p> <p>2005-04-01</p> <p><span class="hlt">Active</span> research in the last two decades indicates that the physical precursor and <span class="hlt">solar</span> dynamo techniques are preferred as practical tools for long-term prediction of <span class="hlt">solar</span> <span class="hlt">activity</span>. But why should we omit more than 23 cycles of <span class="hlt">solar</span> <span class="hlt">activity</span> history, and just use empirical methods or simple autoregressive methods on the basis of observations for the latest eight cycles? In this article, a method based on spectral analysis and neurofuzzy modeling is proposed that is capable of issuing very accurate long-term prediction of sunspot number time series. A locally linear neurofuzzy model is optimized for each of the principal components obtained from singular spectrum analysis, and the multi-step predicted values are recombined to make the sunspot number time series. The proposed method is used for <span class="hlt">solar</span> cycles 22 and 23 and the results are remarkably good in comparison to the predictions made by <span class="hlt">solar</span> dynamo and precursor methods. An early prediction of the maximum smoothed international sunspot number for cycle 24 is 145 in 2011 2012.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040074450&hterms=environment+learning&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Denvironment%2Blearning','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040074450&hterms=environment+learning&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Denvironment%2Blearning"><span id="translatedtitle">DASL-Data and <span class="hlt">Activities</span> for <span class="hlt">Solar</span> Learning</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, Harrison P.; Henney, Carl; Hill, Frank; Gearen, Michael; Pompca, Stephen; Stagg, Travis; Stefaniak, Linda; Walker, Connie</p> <p>2004-01-01</p> <p>DASL-Data and <span class="hlt">Activities</span> for <span class="hlt">Solar</span> Learning Data and <span class="hlt">Activities</span> for <span class="hlt">Solar</span> Learning (DASL) provides a classroom learning environment based on a twenty-five year record of <span class="hlt">solar</span> magnetograms from the National <span class="hlt">Solar</span> Observatory (NSO) at Kitt Peak, AZ. The data, together with image processing software for Macs or PCs, can be used to learn basic facts about the Sun and astronomy at the middle school level. At the high school level, students can study properties of the Sun's magnetic cycle with classroom exercises emphasizing data and error analysis and can participate in a new scientific study, Research in <span class="hlt">Active</span> <span class="hlt">Solar</span> Longitudes (RASL), in collaboration with classrooms throughout the country and scientists at NSO and NASA. We present a half-day course to train teachers in the scientific content of the project and its classroom use. We will provide a compact disc with the data and software and will demonstrate software installation and use, classroom exercises, and participation in RASL with computer projection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9145E..50D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9145E..50D"><span id="translatedtitle"><span class="hlt">Active</span> control of the Chinese Giant <span class="hlt">Solar</span> Telescope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dai, Yichun; Yang, Dehua; Jin, Zhenyu; Liu, Zhong; Qin, Wei</p> <p>2014-07-01</p> <p>The Chinese Giant <span class="hlt">Solar</span> Telescope (CGST) is the next generation <span class="hlt">solar</span> telescope of China with diameter of 8 meter. The unique feature of CGST is that its primary is a ring, which facilitates the polarization detection and thermal control. In its present design and development phase, two primary mirror patterns are considered. For one thing, the primary mirror is expected to construct with mosaic mirror with 24 trapezoidal (or petal) segments, for another thing, a monolithic mirror is also a candidate for its primary mirror. Both of them depend on <span class="hlt">active</span> control technique to maintain the optical quality of the ring mirror. As a <span class="hlt">solar</span> telescope, the working conditions of the CGST are quite different from those of the stellar telescopes. To avoid the image deterioration due to the mirror seeing and dome seeing, especially in the case of the concentration of flux in a <span class="hlt">solar</span> telescope, large aperture <span class="hlt">solar</span> projects prefer to adopt open telescopes and open domes. In this circumstance, higher wind loads act on the primary mirror directly, which will cause position errors and figure errors of the primary with matters worse than those of the current 10-meter stellar telescopes with dome protect. Therefore, it gives new challenges to the <span class="hlt">active</span> control capability, telescope structure design, and wind shielding design. In this paper, the study progress of <span class="hlt">active</span> control of CGST for its mosaic and monolithic mirror are presented, and the wind effects on such two primary mirrors are also investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AAS...21841102H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AAS...21841102H"><span id="translatedtitle">The <span class="hlt">Solar</span> System Ballet: A Kinesthetic Spatial Astronomy <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heyer, Inge; Slater, T. F.; Slater, S. J.; Astronomy, Center; Education ResearchCAPER, Physics</p> <p>2011-05-01</p> <p>The <span class="hlt">Solar</span> System Ballet was developed in order for students of all ages to learn about the planets, their motions, their distances, and their individual characteristics. To teach people about the structure of our <span class="hlt">Solar</span> System can be revealing and rewarding, for students and teachers. Little ones (and some bigger ones, too) often cannot yet grasp theoretical and spatial ideas purely with their minds. Showing a video is better, but being able to learn with their bodies, essentially being what they learn about, will help them understand and remember difficult concepts much more easily. There are three segments to this <span class="hlt">activity</span>, which can be done together or separately, depending on time limits and age of the students. Part one involves a short introductory discussion about what students know about the planets. Then students will act out the orbital motions of the planets (and also moons for the older ones) while holding a physical model. During the second phase we look at the structure of the <span class="hlt">Solar</span> System as well as the relative distances of the planets from the Sun, first by sketching it on paper, then by recreating a scaled version in the class room. Again the students act out the parts of the <span class="hlt">Solar</span> System bodies with their models. The third segment concentrates on recreating historical measurements of Earth-Moon-Sun system. The <span class="hlt">Solar</span> System Ballet <span class="hlt">activity</span> is suitable for grades K-12+ as well as general public informal learning <span class="hlt">activities</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21562517','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562517"><span id="translatedtitle"><span class="hlt">SOLAR</span> CYCLE VARIATIONS OF THE OCCURRENCE OF CORONAL TYPE III RADIO BURSTS AND A NEW <span class="hlt">SOLAR</span> <span class="hlt">ACTIVITY</span> INDEX</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lobzin, Vasili; Cairns, Iver H.; Robinson, Peter A.</p> <p>2011-07-20</p> <p>This Letter presents the results of studies of <span class="hlt">solar</span> cycle variations of the occurrence rate of coronal type III radio bursts. The radio spectra are provided by the Learmonth <span class="hlt">Solar</span> Radio Observatory (Western Australia), part of the USAF Radio <span class="hlt">Solar</span> Telescope Network (RSTN). It is found that the occurrence rate of type III bursts strongly correlates with <span class="hlt">solar</span> <span class="hlt">activity</span>. However, the profiles for the smoothed type III burst occurrence rate differ considerably from those for the sunspot number, 10.7 cm <span class="hlt">solar</span> radio flux, and <span class="hlt">solar</span> flare index. The type III burst occurrence rate (T3BOR) is proposed as a new index of <span class="hlt">solar</span> <span class="hlt">activity</span>. T3BOR provides complementary information about <span class="hlt">solar</span> <span class="hlt">activity</span> and should be useful in different studies including <span class="hlt">solar</span> cycle predictions and searches for different periodicities in <span class="hlt">solar</span> <span class="hlt">activity</span>. This index can be estimated from daily results of the Automated Radio Burst Identification System. Access to data from other RSTN sites will allow processing 24 hr radio spectra in near-real time and estimating true daily values of this index. It is also shown that coronal type III bursts can even occur when there are no visible sunspots on the Sun. However, no evidence is found that the bursts are not associated with <span class="hlt">active</span> regions. It is also concluded that the type III burst productivity of <span class="hlt">active</span> regions exhibits <span class="hlt">solar</span> cycle variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESSD..1113843P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESSD..1113843P"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span> forcing, climate variability and atmospheric circulation patterns on summer floods in Switzerland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peña, J. C.; Schulte, L.; Badoux, A.; Barriendos, M.; Barrera-Escoda, A.</p> <p>2014-12-01</p> <p>The higher frequency of severe flood events in Switzerland in recent decades has given fresh impetus to the study of flood patterns and their possible forcing mechanisms, particularly in mountain environments. This paper presents an index of summer flood damage that considers severe and catastrophic summer floods in Switzerland between 1800 and 2009, and explores the <span class="hlt">influence</span> of <span class="hlt">solar</span> and climate forcings on flood frequencies. In addition, links between floods and low-frequency atmospheric circulation patterns are examined. The flood damage index provides evidence that the 1817-1851, 1881-1927, 1977-1990 and 2005-present flood clusters occur mostly in phase with palaeoclimate proxies. The cross-spectral analysis documents that the periodicities detected in the coherency and phase spectra of 11 (Schwabe cycle) and 104 years (Gleissberg cycle) are related to a high frequency of flooding and <span class="hlt">solar</span> <span class="hlt">activity</span> minima, whereas the 22 year cyclicity detected (Hale cycle) is associated with <span class="hlt">solar</span> <span class="hlt">activity</span> maxima and a decrease in flood frequency. The analysis of atmospheric circulation patterns shows that Switzerland lies close to the border of the summer principal mode: the Summer North Atlantic Oscillation. The Swiss river catchments situated on the centre and southern flank of the Alps are affected by atmospherically unstable areas defined by the positive phase of the Summer North Atlantic Oscillation pattern, while those basins located in the northern slope of the Alps are predominantly associated with the negative phase of the pattern. Furthermore, a change in the low-frequency atmospheric circulation pattern related to the major floods occurred over the period from 1800 to 2009: the Summer North Atlantic Oscillation persists in negative phase during the last cool pulses of the Little Ice Age (1817-1851 and 1881-1927 flood clusters), whereas the positive phases of SNAO prevail during warmer climate of the last four decades (flood clusters from 1977 to present).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMSH21A0319L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMSH21A0319L"><span id="translatedtitle">Magnetic Cloud Polarity and Geomagnetic <span class="hlt">Activities</span> over Three <span class="hlt">Solar</span> Cycles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Y.; Luhmann, J.</p> <p>2006-12-01</p> <p>Interplanetary coronal mass ejections (ICMEs) that show fluxrope magnetic structures are named magnetic clouds (MCs). Majority of the MCs exhibit bipolar signature in their north-south component (Bz) in IMF measurements. The Bz component of a bipolar cloud is either NS (north first then turning south as the MC traverses the spacecraft) or SN. Studies show that the occurrence of these two types of MCs has some <span class="hlt">solar</span> cycle dependence. However it appears to be a complex relationship as the switch between the two types of MCs is not concurrent with either the <span class="hlt">solar</span> polar reversal or the time of the sunspot minimum when the new cycle sunspots start to appear. In this paper, we use ACE <span class="hlt">solar</span> wind and IMF observations to obtain the most updated MC signatures and their temporal variation. In combination with our previously published results, we analyze MC polarity variations over the three <span class="hlt">solar</span> cycles of 21, 22 and 23. Interpretations in terms of their <span class="hlt">solar</span> sources will be attempted. On the other hand, the geomagnetic <span class="hlt">activities</span> over the same <span class="hlt">solar</span> cycles will be studied using geomagnetic indices. The geoeffectiveness of the MC will be evaluated in the aid of Dst indices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ApJ...809..157F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ApJ...809..157F&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> Spectral Irradiance, <span class="hlt">Solar</span> <span class="hlt">Activity</span>, and the Near-Ultra-Violet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fontenla, J. M.; Stancil, P. C.; Landi, E.</p> <p>2015-08-01</p> <p>The previous calculations of the <span class="hlt">Solar</span> Spectral Irradiance (SSI) by the <span class="hlt">Solar</span> Radiation Physical Modeling, version 2 system, are updated in this work by including new molecular photodissociation cross-sections of important species, and many more levels and lines in its treatment of non-LTE radiative transfer. The current calculations including the new molecular photodissociation opacities produce a reduced over-ionizaton of heavy elements in the lower chromosphere and solve the problems with prior studies of the UV SSI in the wavelength range 160-400 nm and now reproduce the available observations with much greater accuracy. Calculations and observations of the near-UV at 0.1 nm resolution and higher are compared. The current set of physical models includes four quiet-Sun and five <span class="hlt">active</span>-region components, from which radiance is computed for ten observing angles. These radiances are combined with images of the <span class="hlt">solar</span> disk to obtain the SSI and Total <span class="hlt">Solar</span> Irradiance and their variations. The computed SSI is compared with measurements from space at several nm resolution and agreement is found within the accuracy level of these measurements. An important result is that the near-UV SSI increase with <span class="hlt">solar</span> <span class="hlt">activity</span> is significant for the photodissociation of ozone in the terrestrial atmosphere because a number of highly variable upper chromospheric lines overlap the ozone Hartley band.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040031767','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040031767"><span id="translatedtitle">Long-Range <span class="hlt">Solar</span> <span class="hlt">Activity</span> Predictions: A Reprieve from Cycle #24's <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richon, K.; Schatten, K.</p> <p>2003-01-01</p> <p>We discuss the field of long-range <span class="hlt">solar</span> <span class="hlt">activity</span> predictions and provide an outlook into future <span class="hlt">solar</span> <span class="hlt">activity</span>. Orbital predictions for satellites in Low Earth Orbit (LEO) depend strongly on exospheric densities. <span class="hlt">Solar</span> <span class="hlt">activity</span> forecasting is important in this regard, as the <span class="hlt">solar</span> ultra-violet (UV) and extreme ultraviolet (EUV) radiations inflate the upper atmospheric layers of the Earth, forming the exosphere in which satellites orbit. Rather than concentrate on statistical, or numerical methods, we utilize a class of techniques (precursor methods) which is founded in physical theory. The geomagnetic precursor method was originally developed by the Russian geophysicist, Ohl, using geomagnetic observations to predict future <span class="hlt">solar</span> <span class="hlt">activity</span>. It was later extended to <span class="hlt">solar</span> observations, and placed within the context of physical theory, namely the workings of the Sun s Babcock dynamo. We later expanded the prediction methods with a <span class="hlt">SOlar</span> Dynamo Amplitude (SODA) index. The SODA index is a measure of the buried <span class="hlt">solar</span> magnetic flux, using toroidal and poloidal field components. It allows one to predict future <span class="hlt">solar</span> <span class="hlt">activity</span> during any phase of the <span class="hlt">solar</span> cycle, whereas previously, one was restricted to making predictions only at <span class="hlt">solar</span> minimum. We are encouraged that <span class="hlt">solar</span> cycle #23's behavior fell closely along our predicted curve, peaking near 192, comparable to the Schatten, Myers and Sofia (1996) forecast of 182+/-30. Cycle #23 extends from 1996 through approximately 2006 or 2007, with cycle #24 starting thereafter. We discuss the current forecast of <span class="hlt">solar</span> cycle #24, (2006-2016), with a predicted smoothed F10.7 radio flux of 142+/-28 (1-sigma errors). This, we believe, represents a reprieve, in terms of reduced fuel costs, etc., for new satellites to be launched or old satellites (requiring reboosting) which have been placed in LEO. By monitoring the Sun s most deeply rooted magnetic fields; long-range <span class="hlt">solar</span> <span class="hlt">activity</span> can be predicted. Although a degree of uncertainty</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987PAICz..66..129B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987PAICz..66..129B"><span id="translatedtitle">High flare <span class="hlt">activity</span> and redistribution of <span class="hlt">solar</span> global magnetic fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bumba, V.; Hejna, L.; Gesztelyi, L.</p> <p></p> <p>It is demonstrated that, both on the global scale and on the scale of large and complex <span class="hlt">active</span> regions, high flare <span class="hlt">activity</span> is closely related to changes in the whole background magnetic-field distribution. It is found that the disturbances of the normal course of magnetic <span class="hlt">active</span> longitudes (MAL) during the years 1965-1980 correlated with the maxima of flare <span class="hlt">activity</span>, while the mode of the MAL distribution correlated with the mean level of <span class="hlt">solar</span> flare numbers. The development of <span class="hlt">activity</span> during the last two submaxima of the 21st cycle, especially the formation of the white-light flare region of April 1984, were parts of global processes in the <span class="hlt">solar</span> atmosphere. They were accompanied by a complete reorganization of the MAL patterns, background field sector structure, and coronal holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900018855','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900018855"><span id="translatedtitle">The QBO and weak external forcing by <span class="hlt">solar</span> <span class="hlt">activity</span>: A three dimensional model study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dameris, M.; Ebel, A.</p> <p>1989-01-01</p> <p>A better understanding is attempted of the physical mechanisms leading to significant correlations between oscillations in the lower and middle stratosphere and <span class="hlt">solar</span> variability associated with the sun's rotation. A global 3-d mechanistic model of the middle atmosphere is employed to investigate the effects of minor artificially induced perturbations. The aim is to explore the physical mechanisms of the dynamical response especially of the stratosphere to weak external forcing as it may result from UV flux changes due to <span class="hlt">solar</span> rotation. First results of numerical experiments dealing about the external forcing of the middle atmosphere by <span class="hlt">solar</span> <span class="hlt">activity</span> were presented elsewhere. Different numerical studies regarding the excitation and propagation of weak perturbations have been continued since then. The model calculations presented are made to investigate the <span class="hlt">influence</span> of the quasi-biennial oscillation (QBO) on the dynamical response of the middle atmosphere to weak perturbations by employing different initial wind fields which represent the west and east phase of the QBO.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RAA....15.1036L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RAA....15.1036L"><span id="translatedtitle">Proton <span class="hlt">activity</span> of the Sun in current <span class="hlt">solar</span> cycle 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Chuan; Miroshnichenko, Leonty I.; Fang, Cheng</p> <p>2015-07-01</p> <p>We present a study of seven large <span class="hlt">solar</span> proton events in the current <span class="hlt">solar</span> cycle 24 (from 2009 January up to the current date). They were recorded by the GOES spacecraft with the highest proton fluxes being over 200 pfu for energies >10 MeV. In situ particle measurements show that: (1) The profiles of the proton fluxes are highly dependent on the locations of their <span class="hlt">solar</span> sources, namely flares or coronal mass ejections (CMEs), which confirms the “heliolongitude rules” associated with <span class="hlt">solar</span> energetic particle fluxes; (2) The <span class="hlt">solar</span> particle release (SPR) times fall in the decay phase of the flare emission, and are in accordance with the times when the CMEs travel to an average height of 7.9 <span class="hlt">solar</span> radii; and (3) The time differences between the SPR and the flare peak are also dependent on the locations of the <span class="hlt">solar</span> <span class="hlt">active</span> regions. The results tend to support the scenario of proton acceleration by the CME-driven shock, even though there exists a possibility of particle acceleration at the flare site, with subsequent perpendicular diffusion of accelerated particles in the interplanetary magnetic field. We derive the integral time-of-maximum spectra of <span class="hlt">solar</span> protons in two forms: a single power-law distribution and a power law roll-over with an exponential tail. It is found that the unique ground level enhancement that occurred in the event on 2012 May 17 displays the hardest spectrum and the largest roll-over energy which may explain why this event could extend to relativistic energies. Supported by the National Natural Science Foundation of China.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22167365','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22167365"><span id="translatedtitle">GLOBAL DYNAMICS OF SUBSURFACE <span class="hlt">SOLAR</span> <span class="hlt">ACTIVE</span> REGIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jouve, L.; Brun, A. S.</p> <p>2013-01-01</p> <p>We present three-dimensional numerical simulations of a magnetic loop evolving in either a convectively stable or unstable rotating shell. The magnetic loop is introduced into the shell in such a way that it is buoyant only in a certain portion in longitude, thus creating an {Omega}-loop. Due to the action of magnetic buoyancy, the loop rises and develops asymmetries between its leading and following legs, creating emerging bipolar regions whose characteristics are similar to those of observed spots at the <span class="hlt">solar</span> surface. In particular, we self-consistently reproduce the creation of tongues around the spot polarities, which can be strongly affected by convection. We further emphasize the presence of ring-shaped magnetic structures around our simulated emerging regions, which we call 'magnetic necklace' and which were seen in a number of observations without being reported as of today. We show that those necklaces are markers of vorticity generation at the periphery and below the rising magnetic loop. We also find that the asymmetry between the two legs of the loop is crucially dependent on the initial magnetic field strength. The tilt angle of the emerging regions is also studied in the stable and unstable cases and seems to be affected both by the convective motions and the presence of a differential rotation in the convective cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SoPh..285..141C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SoPh..285..141C"><span id="translatedtitle">Results of IPS Observations in the Period Near <span class="hlt">Solar</span> <span class="hlt">Activity</span> Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chashei, I. V.; Shishov, V. I.; Tyul'bashev, S. A.; Subaev, I. A.; Oreshko, V. V.</p> <p>2013-07-01</p> <p>IPS observations with the Big Scanning Array of Lebedev Physical Institute (BSA LPI) radio telescope at the frequency 111 MHz have been monitored since 2006. All the sources, about several hundred daily, with a scintillating flux greater than 0.2 Jy are recorded for 24 hours in the 16 beams of the radio telescope covering a sky strip of 8∘ declination width. We present some results of IPS observations for the recent period of low <span class="hlt">solar</span> <span class="hlt">activity</span> considering a statistical ensemble of scintillating radio sources. The dependences of the averaged over ensemble scintillation index on heliocentric distance are considerably weaker than the dependence expected for a spherically symmetric geometry. The difference is especially pronounced in the year 2008 during the very deep <span class="hlt">solar</span> <span class="hlt">activity</span> minimum period. These features are explained by the <span class="hlt">influence</span> of the heliospheric current sheet that is seen as a strong concentration of turbulent <span class="hlt">solar</span> wind plasma aligned with the <span class="hlt">solar</span> equatorial plane. A local maximum of the scintillation index is found in the anti-<span class="hlt">solar</span> direction. Future prospects of IPS observations using BSA LPI are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IzAOP..50..678R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IzAOP..50..678R"><span id="translatedtitle">Manifestation of variations in <span class="hlt">solar</span> <span class="hlt">activity</span> 70-45 Ma ago</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raspopov, O. M.; Dergachev, V. A.; Dmitriev, P. B.; Kozyreva, O. V.</p> <p>2014-12-01</p> <p>Unique paleoenvironmental records (ring widths of fossil trees) with a temporal resolution of 1 year are analyzed with the aim of revealing periodicities in climatic processes during the time interval of 70-45 Ma ago. The periodicities thus obtained are compared with the <span class="hlt">solar</span> and climatic periodicities observed at present. It is shown that quasi-bicentennial and quasi-secular periodicities that can be attributed to the <span class="hlt">influence</span> of <span class="hlt">solar</span> Suess-de Vries and Gleissberg cycles manifest themselves in the most intense manner in climatic oscillations in the past (70-45 Ma ago). The spectra of the paleoclimate data exhibit periodicities that are typical of <span class="hlt">solar</span> <span class="hlt">activity</span>, i.e., the quasi-20-year (Hale cycle) and 11-year (Schwabe cycle) ones derived from the instrumental data and historical observations of sunspots. It can be concluded that analyzing climatic periodicities obtained by paleodendrochronology gives information on the <span class="hlt">solar</span> periodicity that cannot be achieved by other methods. The revealed periodicities are similar in values to the present-day periodicity of <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960014136&hterms=Longitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLongitude','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960014136&hterms=Longitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLongitude"><span id="translatedtitle">Hot spots and <span class="hlt">active</span> longitudes: Organization of <span class="hlt">solar</span> <span class="hlt">activity</span> as a probe of the interior</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bai, Taeil; Hoeksema, J. Todd; Scherrer, Phil H.</p> <p>1995-01-01</p> <p>In order to investigate how <span class="hlt">solar</span> <span class="hlt">activity</span> is organized in longitude, major <span class="hlt">solar</span> flares, large sunspot groups, and large scale photospheric magnetic field strengths were analyzed. The results of these analyses are reported. The following results are discussed: hot spots, initially recognized as areas of high concentration of major flares, are the preferred locations for the emergence of big sunspot groups; double hot spots appear in pairs that rotate at the same rate separated by about 180 deg in longitude, whereas, single hot spots have no such companions; the northern and southern hemispheres behave differently in organizing <span class="hlt">solar</span> <span class="hlt">activity</span> in longitude; the lifetime of hot spots range from one to several <span class="hlt">solar</span> cycles; a hot spot is not always <span class="hlt">active</span> throughout its lifetime, but goes through dormant periods; and hot spots with different rotational periods coexist in the same hemisphere during the same <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JSWSC...3A..18Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JSWSC...3A..18Z"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> and its evolution across the corona: recent advances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zuccarello, Francesca; Balmaceda, Laura; Cessateur, Gael; Cremades, Hebe; Guglielmino, Salvatore L.; Lilensten, Jean; Dudok de Wit, Thierry; Kretzschmar, Matthieu; Lopez, Fernando M.; Mierla, Marilena; Parenti, Susanna; Pomoell, Jens; Romano, Paolo; Rodriguez, Luciano; Srivastava, Nandita; Vainio, Rami; West, Matt; Zuccarello, Francesco P.</p> <p>2013-04-01</p> <p><span class="hlt">Solar</span> magnetism is responsible for the several <span class="hlt">active</span> phenomena that occur in the <span class="hlt">solar</span> atmosphere. The consequences of these phenomena on the <span class="hlt">solar</span>-terrestrial environment and on Space Weather are nowadays clearly recognized, even if not yet fully understood. In order to shed light on the mechanisms that are at the basis of the Space Weather, it is necessary to investigate the sequence of phenomena starting in the <span class="hlt">solar</span> atmosphere and developing across the outer layers of the Sun and along the path from the Sun to the Earth. This goal can be reached by a combined multi-disciplinary, multi-instrument, multi-wavelength study of these phenomena, starting with the very first manifestation of <span class="hlt">solar</span> <span class="hlt">active</span> region formation and evolution, followed by explosive phenomena (i.e., flares, erupting prominences, coronal mass ejections), and ending with the interaction of plasma magnetized clouds expelled from the Sun with the interplanetary magnetic field and medium. This wide field of research constitutes one of the main aims of COST Action ES0803: Developing Space Weather products and services in Europe. In particular, one of the tasks of this COST Action was to investigate the Progress in Scientific Understanding of Space Weather. In this paper we review the state of the art of our comprehension of some phenomena that, in the scenario outlined above, might have a role on Space Weather, focusing on the researches, thematic reviews, and main results obtained during the COST Action ES0803.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900049510&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DButterfly','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900049510&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DButterfly"><span id="translatedtitle">A <span class="hlt">solar</span> cycle timing predictor - The latitude of <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schatten, Kenneth H.</p> <p>1990-01-01</p> <p>A 'Spoerer butterfly' method is used to examine <span class="hlt">solar</span> cycle 22. It is shown from the latitude of <span class="hlt">active</span> regions that the cycle can now be expected to peak near November 1989 + or - 8 months, basically near the latter half of 1989.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E1841P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E1841P"><span id="translatedtitle">Topside electron temperature models for low and high <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pandey, V.; Sethi, N.; Mahajan, K.</p> <p></p> <p>It is now well known that in the topside ionosphere, thermal conduction from the protonosphere becomes the dominant factor over the "heating" and "loss" terms in shaping the ionospheric electron temperature (Te) profile. By analyzing a limited data base of incoherent scatter (i.s.) Te measurements , Mahajan and Pandey (1980) reported a correlation between the topside electron heat flux and electron density, Ne at 400 km. In the recent years, since attention has been steadily mounting for the empirical modelling of Te, in this paper we exploit the large data base of i.s. measurements of Te and Ne at Arecibo, during 1989 -90 (high <span class="hlt">solar</span> <span class="hlt">activity</span>), as well as during 1975-76 ( low <span class="hlt">solar</span> <span class="hlt">activity</span>). We again find a functional relationship between heat flux and electron density in the topside ionosphere during both the <span class="hlt">solar</span> <span class="hlt">activities</span>. These functional relationships are used to generate topside Te profiles. As the current IRI Te model does not include variations with <span class="hlt">solar</span> <span class="hlt">activity</span>, the present work can contribute in improving the topside Te model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSMSH23B..01V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMSH23B..01V"><span id="translatedtitle">Analysis of <span class="hlt">Solar</span> Magnetic <span class="hlt">Activity</span> with the Wavelet Coherence Method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velasco, V. M.; Perez-Peraza, J. A.; Mendoza, B. E.; Valdes-Galicia, J. F.; Sosa, O.; Alvarez-Madrigal, M.</p> <p>2007-05-01</p> <p>The origin, behavior and evolution of the <span class="hlt">solar</span> magnetic field is one of the main challenges of observational and theoretical <span class="hlt">solar</span> physics. Up to now the Dynamo theory gives us the best approach to the problem. However, it is not yet able to predict many features of the <span class="hlt">solar</span> <span class="hlt">activity</span>, which seems not to be strictly a periodical phenomenon. Among the indicators of <span class="hlt">solar</span> magnetic variability there is the 11-years cycle of sunspots, as well as the <span class="hlt">solar</span> magnetic cycle of 22 years (the Hale cycle). In order to provide more elements to the Dynamo theory that could help it in the predicting task, we analyze here the plausible existence of other periodicities associated with the <span class="hlt">solar</span> magnetic field. In this preliminary work we use historical data (sunspots and aurora borealis), proxies (Be10 and C14) and modern instrumental data (Coronal Holes, Cosmic Rays, sunspots, flare indexes and <span class="hlt">solar</span> radio flux at 10.7 cm). To find relationships between different time-frequency series we have employed the t Wavelet Coherence technique: this technique indicates if two time-series of <span class="hlt">solar</span> <span class="hlt">activity</span> have the same periodicities in a given time interval. If so, it determines whether such relation is a linear one or not. Such a powerful tool indicates that, if some periodicity at a given frequency has a confidence level below 95%, it appears very lessened or does not appear in the Wavelet Spectral Analysis, such periodicity does not exist . Our results show that the so called Glaisberg cycle of 80-90 years and the periodicity of 205 years (the Suess cycle) do not exist . It can be speculated that such fictitious periodicities hav been the result of using the Fourier transform with series with are not of stationary nature, as it is the case of the Be10 and C14 series. In contrast we confirm the presence of periodicities of 1.3, 1.7, 3.5, 5.5, 7, 60, 120 and 240 years. The concept of a Glaisberg cycle falls between those of 60 and 120 years. We conclude that the periodicity of 120 years</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JGRA..116.4320L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JGRA..116.4320L&link_type=ABSTRACT"><span id="translatedtitle">The ionosphere under extremely prolonged low <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Libo; Chen, Yiding; Le, Huijun; Kurkin, Vladimir I.; Polekh, Nelya M.; Lee, Chien-Chih</p> <p>2011-04-01</p> <p>A critical question in ionospheric physics is the state of the ionosphere and relevant processes under extreme <span class="hlt">solar</span> <span class="hlt">activities</span>. The <span class="hlt">solar</span> <span class="hlt">activity</span> during 2007-2009 is extremely prolonged low, which offers us a unique opportunity to explore this issue. In this study, we collected the global ionosonde measurements of the F2 layer critical frequency (foF2), E layer critical frequency (foE), and F layer virtual height (h‧F) and the total electron content (TEC) maps produced by the Jet Propulsion Laboratory, which were retrieved from dual-frequency GPS receivers distributed worldwide, to investigate the ionospheric phenomena during <span class="hlt">solar</span> minimum of cycle 23/24, particularly the difference in the ionosphere between <span class="hlt">solar</span> minima of cycle 23/24 and the preceding cycles. The analysis indicates that the moving 1 year mean foF2 at most ionosonde stations and the global average TEC went to the lowest during cycle 23/24 minimum. The <span class="hlt">solar</span> cycle differences in foF2 minima display local time dependence, being more negative during the daytime than at night. Furthermore, the cycle difference in daytime foF2 minima is about -0.5 MHz and even reaches to around -1.2 MHz. In contrast, a complex picture presents in global h‧F and foE. Evident reduction exists prevailingly in the moving 1 year mean h‧F at most stations, while no huge differences are detected at several stations. A compelling feature is the increase in foE at some stations, which requires independent data for further validation. Quantitative analysis indicates that record low foF2 and low TEC can be explained principally in terms of the decline in <span class="hlt">solar</span> extreme ultraviolet irradiance recorded by SOHO/SEM, which suggests low <span class="hlt">solar</span> EUV being the prevailing contributor to the unusual low electron density in the ionosphere during cycle 23/24 minimum. It also verifies that a quadratic fitting still reasonably captures the <span class="hlt">solar</span> variability of foF2 and global average TEC at such low <span class="hlt">solar</span> <span class="hlt">activity</span> levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11680737','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11680737"><span id="translatedtitle">Pesticide <span class="hlt">influence</span> on soil enzymatic <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sannino, F; Gianfreda, L</p> <p>2001-11-01</p> <p>The <span class="hlt">influence</span> of four pesticides, e.g. glyphosate, paraquat, atrazine, and carbaryl, on the <span class="hlt">activities</span> of invertase, urease and phosphatase of twenty-two soils, numbered as 1-22, was investigated. Soils displayed a general variability of enzyme <span class="hlt">activities</span> with invertase being more abundant than urease and phosphatase in the order listed. The addition of glyphosate and paraquat <span class="hlt">activated</span> invertase and urease <span class="hlt">activities</span> in several soils. Increments of invertase <span class="hlt">activity</span> ranged from a very low increase (+4%) up to +204% in soils 11 and 14, respectively. Smaller increases were measured for urease. A general inhibitory effect (from 5% to 98%) was observed for phosphatase in the presence of glyphosate. The effects of atrazine and carbaryl on the three soil enzymes were evaluated against that exhibited by methanol, the solvent used for their solubilization. In almost all soils, atrazine further inhibited invertase <span class="hlt">activity</span> with respect to the inhibitory effect shown by methanol. By contrast, consistent <span class="hlt">activation</span> effects (from 61% to 10217%) were measured for urease with methanol alone and/or methanol-pesticide mixtures. Contradictory results were observed with phosphatase. Similarities found between the results obtained with enzymes in soils and those measured with synthetic enzyme complexes (e.g. free enzymes and/or clay-, organo-, and organo-clay-enzyme complexes) exposed to the same pesticides allowed some relationships between responses of soil enzymes to pesticides and soil properties to be hypothesized. PMID:11680737</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22078472','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22078472"><span id="translatedtitle">THE MAGNETIC ENERGY-HELICITY DIAGRAM OF <span class="hlt">SOLAR</span> <span class="hlt">ACTIVE</span> REGIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tziotziou, Kostas; Georgoulis, Manolis K.; Raouafi, Nour-Eddine</p> <p>2012-11-01</p> <p>Using a recently proposed nonlinear force-free method designed for single-vector magnetograms of <span class="hlt">solar</span> <span class="hlt">active</span> regions, we calculate the instantaneous free magnetic energy and relative magnetic helicity budgets in 162 vector magnetograms corresponding to 42 different <span class="hlt">active</span> regions. We find a statistically robust, monotonic correlation between the free magnetic energy and the relative magnetic helicity in the studied regions. This correlation implies that magnetic helicity, in addition to free magnetic energy, may be an essential ingredient for major <span class="hlt">solar</span> eruptions. Eruptive <span class="hlt">active</span> regions appear well segregated from non-eruptive ones in both free energy and relative helicity with major (at least M-class) flares occurring in <span class="hlt">active</span> regions with free energy and relative helicity exceeding 4 Multiplication-Sign 10{sup 31} erg and 2 Multiplication-Sign 10{sup 42} Mx{sup 2}, respectively. The helicity threshold agrees well with estimates of the helicity contents of typical coronal mass ejections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..tmp...74M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..tmp...74M"><span id="translatedtitle">An Alternative Measure of <span class="hlt">Solar</span> <span class="hlt">Activity</span> from Detailed Sunspot Datasets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muraközy, J.; Baranyi, T.; Ludmány, A.</p> <p>2016-05-01</p> <p>The sunspot number is analyzed by using detailed sunspot data, including aspects of observability, sunspot sizes, and proper identification of sunspot groups as discrete entities of <span class="hlt">solar</span> <span class="hlt">activity</span>. The tests show that in addition to the subjective factors there are also objective causes of the ambiguities in the series of sunspot numbers. To introduce an alternative <span class="hlt">solar-activity</span> measure, the physical meaning of the sunspot number has to be reconsidered. It contains two components whose numbers are governed by different physical mechanisms and this is one source of the ambiguity. This article suggests an <span class="hlt">activity</span> index, which is the amount of emerged magnetic flux. The only long-term proxy measure is the detailed sunspot-area dataset with proper calibration to the magnetic flux. The Debrecen sunspot databases provide an appropriate source for the establishment of the suggested <span class="hlt">activity</span> index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21337916','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21337916"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span> heating on the performance of integrated <span class="hlt">solar</span> cell microstrip patch antennas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roo-Ons, M.J.; Shynu, S.V.; Ammann, M.J.; Seredynski, M.; McCormack, S.J.; Norton, B.</p> <p>2010-09-15</p> <p>The integration of microstrip patch antennas with photovoltaics has been proposed for applications in autonomous wireless communication systems located on building facades. Full integration was achieved using polycrystalline silicon <span class="hlt">solar</span> cells as both antenna ground plane and direct current power generation in the same device. An overview of the proposed photovoltaic antenna designs is provided and the variation characterised of the electromagnetic properties of the device with temperature and <span class="hlt">solar</span> radiation. Measurements for both copper and <span class="hlt">solar</span> antennas are reported on three different commercial laminates with contrasting values for thermal coefficient of the dielectric constant. (author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E1494K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E1494K&link_type=ABSTRACT"><span id="translatedtitle">Evidence of plasma heating in <span class="hlt">solar</span> microflares during the minimum of <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirichenko, Alexey; Bogachev, Sergey</p> <p></p> <p>We present a statistical study of 80 <span class="hlt">solar</span> microflares observed during the deep minimum of <span class="hlt">solar</span> <span class="hlt">activity</span> between 23 and 24 <span class="hlt">solar</span> cycles. Our analysis covers the following characteristics of the flares: thermal energy of flaring plasma, its temperature and its emission measure in soft X-rays. The data were obtained during the period from April to July of 2009, which was favorable for observations of weak events because of very low level of <span class="hlt">solar</span> <span class="hlt">activity</span>. The most important part of our analysis was an investigation of extremely weak microflares corresponding to X-ray class below A1.0. We found direct evidence of plasma heating in more than 90% of such events. Temperature of flaring plasma was determined under the isothermal approximation using the data of two <span class="hlt">solar</span> instruments: imaging spectroheliometer MISH onboard Coronas-Photon spacecraft and X-ray spectrophotometer SphinX operating in energy range 0.8 - 15 keV. The main advantage of MISH is the ability to image high temperature plasma (T above 4 MK) without a low-temperature background. The SphinX data was selected due to its high sensitivity, which makes available the registration of X-ray emission from extremely weak microflares corresponding GOES A0.1 - A0.01 classes. The temperature we obtained lies in the range from 2.6 to 13.6 MK, emission measure, integrated over the range 1 - 8 Å - 2.7times10(43) - 4.9times10(47) cm (-3) , thermal energy of flaring region - 5times10(26) - 1.6times10(29) erg. We compared our results with the data obtained by Feldman et. al. 1996 and Ryan et. al. 2012 for <span class="hlt">solar</span> flares with X-ray classes above A2.0 and conclude that the relation between X-ray class of <span class="hlt">solar</span> flare and its temperature is strongly different for ordinary flares (above A2.0) and for weak microflares (A0.01 - A2.0). Our result supports the idea that weak <span class="hlt">solar</span> events (microflares and nanoflares) may play significant a role in plasma heating in <span class="hlt">solar</span> corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25247788','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25247788"><span id="translatedtitle">Modelling the <span class="hlt">influence</span> of photospheric turbulence on <span class="hlt">solar</span> flare statistics.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mendoza, M; Kaydul, A; de Arcangelis, L; Andrade, J S; Herrmann, H J</p> <p>2014-01-01</p> <p><span class="hlt">Solar</span> flares stem from the reconnection of twisted magnetic field lines in the <span class="hlt">solar</span> photosphere. The energy and waiting time distributions of these events follow complex patterns that have been carefully considered in the past and that bear some resemblance with earthquakes and stockmarkets. Here we explore in detail the tangling motion of interacting flux tubes anchored in the plasma and the energy ejections resulting when they recombine. The mechanism for energy accumulation and release in the flow is reminiscent of self-organized criticality. From this model, we suggest the origin for two important and widely studied properties of <span class="hlt">solar</span> flare statistics, including the time-energy correlations. We first propose that the scale-free energy distribution of <span class="hlt">solar</span> flares is largely due to the twist exerted by the vorticity of the turbulent photosphere. Second, the long-range temporal and time-energy correlations appear to arise from the tube-tube interactions. The agreement with satellite measurements is encouraging. PMID:25247788</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=199447&keyword=photochemistry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65296512&CFTOKEN=38075902','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=199447&keyword=photochemistry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=65296512&CFTOKEN=38075902"><span id="translatedtitle">Glacial <span class="hlt">Influences</span> on <span class="hlt">Solar</span> Radiation in a Subarctic Sea.</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Understanding macroscale processes controlling <span class="hlt">solar</span> radia­tion in marine systems will be important in interpreting the potential effects of global change from increasing ultraviolet radiation (UV) and glacial retreat. This study provides the first quantitative assessment of UV i...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcGeo..57...64M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcGeo..57...64M"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> and life: a review</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Messerotti, Mauro; Chela-Flores, Julián</p> <p>2009-03-01</p> <p>During the early stages of the study of the origin of life, not enough attention was paid to the question of the correlation of chemical evolution on Earth and the all-important evolution of the still-to-be understood early Sun. Today, due to the advent of a significant fleet of space missions and the possibility of performing experiments in the International Space Station (ISS), a meaningful study begins to be possible concerning factors that led to an early onset of life on Earth. We wish to review and update recent work concerning the frontier between Space Weather (SpW) and Astrobiology. We argue that the present robust programs of various space agencies reinforce our hope for a better understanding of the bases of Astrobiology. Eventually, with a more realistic model of the Sun, more reliable discussions of all the factors <span class="hlt">influencing</span> the origin of life on Earth, and hence Astrobiology, will be possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..tmp...84D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..tmp...84D"><span id="translatedtitle">Seismic Holography of the <span class="hlt">Solar</span> Interior near the Maximum and Minimum of <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Díaz Alfaro, M.; Pérez Hernández, F.; González Hernández, I.; Hartlep, T.</p> <p>2016-06-01</p> <p>The base of the convection zone and the tachocline play a major role in the study of the dynamics of the Sun, especially in the <span class="hlt">solar</span> dynamo. Here, we present a phase-sensitive helioseismic holography method to infer changes in the sound-speed profile of the <span class="hlt">solar</span> interior. We test the technique using numerically simulated data by Zhao et al. (Astrophys. J. 702, 1150, 2009) with sound-speed perturbations at 0.7 R_{⊙ }. The technique adequately recovers the perturbed sound-speed profile and is seen to be capable of detecting changes in the sound speed as low as 0.05 %. We apply the method to two GONG <span class="hlt">solar</span> time series of approximately one year, each comprising 13 Bartels rotations, BR2295-BR2307 and BR2387-BR2399, near the maximum and at a minimum of <span class="hlt">solar</span> <span class="hlt">activity</span>, respectively. We successfully recover a sound-speed variation with respect to a standard <span class="hlt">solar</span> model, consistent with previous results. However, we fail to recover a realistic sound-speed variation between maximum and minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH53B2503A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH53B2503A"><span id="translatedtitle">IPS of the Radio Source 3C48 During the Periods of Low and High <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguilar-Rodriguez, E.; Tyul'bashev, S. A.; Chashei, I. V.; Romero-Hernandez, E.</p> <p>2015-12-01</p> <p>We present a comparative study of three techniques used to estimate the scintillation index (m) using interplanetary scintillation (IPS) observations carried out by the Big Scanning Array (BSA), that operates at a frequency of 111 MHz. These techniques are based on: rms analysis on-source and off-source (classic), Fourier and wavelet transforms. IPS data are analyzed separately for the period of low <span class="hlt">solar</span> <span class="hlt">activity</span> (2007-2009), and for the year 2013, near the <span class="hlt">solar</span> <span class="hlt">activity</span> maximum. Our results show that in general, these methods are equivalent. We analyze the radial dependence of scintillation index at meter wavelengths during these two periods. It is found that the observed radial dependence of scintillation index during both periods of the cycle 24 is more flat than the theoretical dependence expected for the case of <span class="hlt">solar</span> wind spherical symmetry. This flattening can be explained in terms of the <span class="hlt">influence</span> of the heliospheric current sheet during periods of low <span class="hlt">solar</span> <span class="hlt">activity</span>, and the <span class="hlt">influence</span> of <span class="hlt">solar</span> disturbances, such as coronal mass ejections (CMEs), for periods of high <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2909717','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2909717"><span id="translatedtitle">Parental <span class="hlt">Influence</span> on Young Children's Physical <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zecevic, Cheryl A.; Tremblay, Line; Lovsin, Tanya; Michel, Lariviere</p> <p>2010-01-01</p> <p>Parents <span class="hlt">influence</span> on their young children's physical <span class="hlt">activity</span> (PA) behaviours was examined in a sample of 102 preschool-aged children (54 boys). Questionnaires regarding family sociodemographics and physical <span class="hlt">activity</span> habits were completed. Results showed that children who received greater parental support for <span class="hlt">activity</span> (B = .78, P < .10) and had parents who rated PA as highly enjoyable (B = .69, P < .05) were significantly more likely to engage in one hour or more of daily PA. Being an older child (B = −.08, P < .01), having older parents (B = −.26, P < .01), and watching more than one hour of television/videos per day (B = 1.55, P < .01) reduced the likelihood that a child would be rated as highly <span class="hlt">active</span>. Children who received greater parental support for PA were 6.3 times more likely to be highly <span class="hlt">active</span> than inactive (B = 1.44, P < .05). Thus, parents can promote PA among their preschoolers, not only by limiting TV time but also by being highly supportive of their children's <span class="hlt">active</span> pursuits. PMID:20671967</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740024125','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740024125"><span id="translatedtitle"><span class="hlt">Solar</span> neutrinos and the <span class="hlt">influence</span> of radiative opacities on <span class="hlt">solar</span> models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carson, T. R.; Ezer, D.; Stothers, R.</p> <p>1973-01-01</p> <p>Use of new radiative opacities based on the hot Thomas-Fermi model of the atom yields a predicted <span class="hlt">solar</span> neutrino flux which is still considerably larger than the flux observed in Davis's Cl-37 experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3353T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3353T"><span id="translatedtitle">Major geomagnetic storm due to <span class="hlt">solar</span> <span class="hlt">activity</span> (2006-2013).</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tiwari, Bhupendra Kumar</p> <p></p> <p>Major geomagnetic storm due to <span class="hlt">solar</span> <span class="hlt">activity</span> (2006-2013). Bhupendra Kumar Tiwari Department of Physics, A.P.S.University, Rewa(M.P.) Email: - btiwtari70@yahoo.com mobile 09424981974 Abstract- The geospace environment is dominated by disturbances created by the sun, it is observed that coronal mass ejection (CME) and <span class="hlt">solar</span> flare events are the causal link to <span class="hlt">solar</span> <span class="hlt">activity</span> that produces geomagnetic storm (GMS).CMEs are large scale magneto-plasma structures that erupt from the sun and propagate through the interplanetary medium with speeds ranging from only a few km/s to as large as 4000 km/s. When the interplanetary magnetic field associated with CMEs impinges upon the earth’s magnetosphere and reconnect occur geomagnetic storm. Based on the observation from SOHO/LASCO spacecraft for <span class="hlt">solar</span> <span class="hlt">activity</span> and WDC for geomagnetism Kyoto for geomagnetic storm events are characterized by the disturbance storm time (Dst) index during the period 2006-2013. We consider here only intense geomagnetic storm Dst <-100nT, are 12 during 2006-2013.Geomagnetic storm with maximum Dst< -155nT occurred on Dec15, 2006 associated with halo CME with Kp-index 8+ and also verify that halo CME is the main cause to produce large geomagnetic storms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/323663','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/323663"><span id="translatedtitle">Several efficiency <span class="hlt">influencing</span> factors in CdTe/CdS <span class="hlt">solar</span> cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Li, K. |; Feng, Z.C. |; Wee, A.T.S.</p> <p>1998-12-31</p> <p>Several efficiency <span class="hlt">influencing</span> factors in MOCVD-grown CdTe/CdS <span class="hlt">solar</span> cells, including preferential crystal orientation of CdTe layers, CdTe grain size and surface roughness, interfacial mixing, and surface and interface geometrical morphology, are studied. X-ray diffraction (XRD) shows that polycrystalline CdTe/CdS <span class="hlt">solar</span> cells with higher efficiencies tend to have more (111) planes of CdTe parallel to the macro-surface. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis reveal the relationship between the grain size/surface roughness and cell efficiency. Secondary ion mass spectroscopy (SIMS) and Auger electron spectroscopy (AES) depth profiling show that the interfacial geometrical morphology has a significant <span class="hlt">influence</span> on the efficiency of CdTe/CdS <span class="hlt">solar</span> cells. Finally it is shown that interfacial mixing reduces the number of interfacial states and recombination centers and the energy loss due to internal reflectance, enhancing the performance of the <span class="hlt">solar</span> cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAG...118...24S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAG...118...24S"><span id="translatedtitle">The environmental magnetic record of palaeoenvironmental variations during the past 3100 years: A possible <span class="hlt">solar</span> <span class="hlt">influence</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandeep, K.; Shankar, R.; Warrier, Anish K.; Weijian, Z.; Xuefeng, Lu</p> <p>2015-07-01</p> <p>Sediments from Pookot Lake (PK) in southern India have provided a record of local environmental changes and catchment processes during the past 3100 cal. years B.P. Variations in the rock magnetic parameters (χlf, χfd, χARM and IRM's at different field strengths) of sediments from two AMS 14C-dated cores reflect climate-induced changes in the catchment of Pookot Lake. Assuming that rainfall is most likely the dominant driving mechanism behind the rock magnetic variations of PK sediments, the environmental history of the site has been reconstructed. Rock magnetic parameters exhibit significant variations during the past 3100 years. The palaeoenvironmental history of the Pookot Lake region may be divided into three phases. During the first phase (~ 3100 to 2500 cal. years B.P.), catchment erosion and detrital influx were high, indicating a strong monsoon. The second phase, which lasted from 2500 to 1000 cal. years B.P., was characterised by low and steady rainfall, resulting in a low and uniform catchment erosion and detrital influx. Phase 2 was interspersed with brief intervals of strong monsoon and characterised by frequent drying up of the lake. During Phase 3 (~ 1000 cal. years B.P. to the present), catchment erosion was high, indicating a shift to strong monsoonal conditions. It appears that monsoonal rainfall in the region is <span class="hlt">influenced</span> by <span class="hlt">solar</span> <span class="hlt">activity</span>, with periods of high total <span class="hlt">solar</span> irradiance being characterised by high rainfall and vice versa; it was relatively low during the Little Ice Age and high during the Medieval Warm Period. The magnetic susceptibility (χlf) data exhibit a number of periodicities which might have a <span class="hlt">solar</span> origin. The χlf record exhibits similarities with other continental and marine palaeoclimatic records from the region, indicating that regional trends in the monsoon during the Late Holocene are broadly similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhTea..54...36B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhTea..54...36B"><span id="translatedtitle">Some Daytime <span class="hlt">Activities</span> in <span class="hlt">Solar</span> Astronomy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burin, Michael J.</p> <p>2016-01-01</p> <p>This century's transits of Venus (2004, 2012) captured significant public attention, reminding us that the wonders of astronomy need not be confined to the night. And while nighttime telescope viewing gatherings (a.k.a. "star parties") are perennially popular, astronomy classes are typically held in the daytime. The logistics of coordinating students outside of class can often be problematic, leading to dark-sky <span class="hlt">activities</span> that are relegated to extra credit for only those who can attend.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AAS...22315113N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AAS...22315113N"><span id="translatedtitle">Interplanetary proton flux and <span class="hlt">solar</span> wind conditions for different <span class="hlt">solar</span> <span class="hlt">activities</span> interacting with spacecraft and astronauts in space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nejat, Cyrus</p> <p>2014-01-01</p> <p>The goal of this research is to determine the interplanetary proton flux and <span class="hlt">solar</span> wind conditions by using data from several satellites such as Advanced Composition Explorer (ACE), Geostationary Operational Environmental Satellites (GOES) in particular GOES 9, GOES 11, GOES 12, GOES 13, and <span class="hlt">Solar</span> Heliospheric Observatory (SOHO) to determine proton flux in different <span class="hlt">solar</span> wind conditions. The data from above satellites were used to determine space weather conditions in which the goals are to evaluate proton fluxes for four periods of <span class="hlt">solar</span> cycle <span class="hlt">activity</span>: a <span class="hlt">solar</span> cycle 23/24 minimum (2008), close to a <span class="hlt">solar</span> cycle 22/23 minimum (1997), with intermediate <span class="hlt">activity</span> (2011) and for about maximum <span class="hlt">activity</span> for the cycle 23 (2003), to compare data of two period of <span class="hlt">solar</span> cycle in 2003 and 2008 (Max vs. Min), to compare data of two period of <span class="hlt">solar</span> cycle in 1997 and 2008 (Min vs. Min), to compare soft X-ray flux from SOHO with proton 1-10 MeV flux from GOES 9 for strong flare in 1997. To conclude the above evaluations are being used to determine the interaction between the space weather conditions and the following consequences of these conditions important for astronautics and everyday human <span class="hlt">activity</span>: 1- Satellite and Spacecraft charging, 2-Dangerous conditions for onboard electronics and astronauts during strong <span class="hlt">solar</span> flare events, and 3- Total Electron Content (TEC), Global Positioning System (GPS), and radio communication problems related to <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.147...21M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.147...21M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> variations of nocturnal thermospheric meridional winds over Indian longitude sector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madhav Haridas, M. K.; Manju, G.; Arunamani, T.</p> <p>2016-09-01</p> <p>The night time F-layer base height information from ionosondes located at two equatorial stations Trivandrum (TRV 8.5°N, 77°E) and Sriharikota (SHAR 13.7°N, 80.2°E) spanning over two decades are used to derive the climatology of equatorial nocturnal Thermospheric Meridional Winds (TMWs) prevailing during High <span class="hlt">Solar</span> <span class="hlt">Activity</span> (HSA) and Low <span class="hlt">Solar</span> <span class="hlt">Activity</span> (LSA) epochs. The important inferences from the analysis are 1) Increase in mean equatorward winds observed during LSA compared to HSA during pre midnight hours; 25 m/s for VE (Vernal Equinox) and 20 m/s for SS (Summer Solstice), AE (autumnal Equinox) and WS (Winter Solstice). 2) Mean wind response to <span class="hlt">Solar</span> Flux Unit (SFU) is established quantitatively for all seasons for pre-midnight hours; rate of increase is 0.25 m/s/SFU for VE, 0.2 m/s/SFU for SS and WS and 0.08 m/s/SFU for AE. 3) Theoretical estimates of winds for the two epochs are performed and indicate the role of ion drag forcing as a major factor <span class="hlt">influencing</span> TMWs. 4) Observed magnitude of winds and rate of flux dependencies are compared to thermospheric wind models. 5) Equinoctial asymmetry in TMWs is observed for HSA at certain times, with more equatorward winds during AE. These observations lend a potential to parameterize the wind components and effectively model the winds, catering to <span class="hlt">solar</span> <span class="hlt">activity</span> variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EGUGA..16.2614P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EGUGA..16.2614P&link_type=ABSTRACT"><span id="translatedtitle">The Impact of Level of <span class="hlt">Solar</span> <span class="hlt">Activity</span> on Mortality by Cause in Longtime Period</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Podolska, Katerina</p> <p>2014-05-01</p> <p>The aim of this presentation is to show the dependence of the intensity of mortality in the Czech Republic, according to the chosen causes of death according to ICD-10, on the <span class="hlt">solar</span> <span class="hlt">activity</span> during the increasing and decreasing phase of the <span class="hlt">solar</span> cycle No.23 in the period 1994-2011. We use the methods of multivariate statistical analysis. The typology of time profiles for the causes of death is identified with the help of cluster analysis using time. The <span class="hlt">solar</span> <span class="hlt">activity</span> is represented by the indices R, Kp, F10.7 and Dst, and also by the height of the F2 layer and TEC for the Czech Republic. There are investigated groups of causes of death according to ICD-10 II. Neoplasms, VI. Diseases of the nervous system, XII. Diseases of the skin and subcutaneous tissue and XVII. Congenital malformations, deformations and chromosomal abnormalities. The correlation between the intensity of mortality from cardiovascular disease e.g. I21 (acute myocardial infarction) and I64 (stroke) and birth defect e.g. Q91 (Edwards' and Pataus' syndrom) and the <span class="hlt">solar</span> <span class="hlt">activity</span> parameters is discovered, as well as a stronger dependence on the height of the F2 layer and TEC. We also explored the <span class="hlt">influence</span> of the above parameters on mortality by causes on degenerative diseases. Typology of time profiles for these causes of death are identified by cluster analysis using time and have found large differences between diagnoses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1260817-do-solar-cycles-influence-giant-cell-arteritis-rheumatoid-arthritis-incidence','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1260817-do-solar-cycles-influence-giant-cell-arteritis-rheumatoid-arthritis-incidence"><span id="translatedtitle">Do <span class="hlt">solar</span> cycles <span class="hlt">influence</span> giant cell arteritis and rheumatoid arthritis incidence?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Wing, Simon; Rider, Lisa G.; Johnson, Jay R.; Miller, Federick W.; Matteson, Eric L.; Crowson, C. S.; Gabriel, S. E.</p> <p>2015-05-15</p> <p>Our objective was to examine the <span class="hlt">influence</span> of <span class="hlt">solar</span> cycle and geomagnetic effects on the incidence of giant cell arteritis (GCA) and rheumatoid arthritis (RA). Methods: We used data from patients with GCA (1950-2004) and RA (1955-2007) obtained from population-based cohorts. Yearly trends in age-adjusted and sex-adjusted incidence were correlated with the F10.7 index (<span class="hlt">solar</span> radiation at 10.7 cm wavelength, a proxy for the <span class="hlt">solar</span> extreme ultraviolet radiation) and AL index (a proxy for the westward auroral electrojet and a measure of geomagnetic <span class="hlt">activity</span>). Fourier analysis was performed on AL, F10.7, and GCA and RA incidence rates. Results: The correlationmore » of GCA incidence with AL is highly significant: GCA incidence peaks 0-1 year after the AL reaches its minimum (ie, auroral electrojet reaches a maximum). The correlation of RA incidence with AL is also highly significant. RA incidence rates are lowest 5-7 years after AL reaches maximum. AL, GCA and RA incidence power spectra are similar: they have a main peak (periodicity) at about 10 years and a minor peak at 4-5 years. However, the RA incidence power spectrum main peak is broader (8-11 years), which partly explains the lower correlation between RA onset and AL. The auroral electrojets may be linked to the decline of RA incidence more strongly than the onset of RA. The incidences of RA and GCA are aligned in geomagnetic latitude. Conclusions: AL and the incidences of GCA and RA all have a major periodicity of about 10 years and a secondary periodicity at 4-5 years. Geomagnetic <span class="hlt">activity</span> may explain the temporal and spatial variations, including east-west skewness in geographic coordinates, in GCA and RA incidence, although the mechanism is unknown. Lastly, the link with <span class="hlt">solar</span>, geospace and atmospheric parameters need to be investigated. These novel findings warrant examination in other populations and with other autoimmune diseases.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4442155','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4442155"><span id="translatedtitle">Do <span class="hlt">solar</span> cycles <span class="hlt">influence</span> giant cell arteritis and rheumatoid arthritis incidence?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wing, Simon; Rider, Lisa G; Johnson, Jay R; Miller, Federick W; Matteson, Eric L; Gabriel, Sherine E</p> <p>2015-01-01</p> <p>Objective To examine the <span class="hlt">influence</span> of <span class="hlt">solar</span> cycle and geomagnetic effects on the incidence of giant cell arteritis (GCA) and rheumatoid arthritis (RA). Methods We used data from patients with GCA (1950–2004) and RA (1955–2007) obtained from population-based cohorts. Yearly trends in age-adjusted and sex-adjusted incidence were correlated with the F10.7 index (<span class="hlt">solar</span> radiation at 10.7 cm wavelength, a proxy for the <span class="hlt">solar</span> extreme ultraviolet radiation) and AL index (a proxy for the westward auroral electrojet and a measure of geomagnetic <span class="hlt">activity</span>). Fourier analysis was performed on AL, F10.7, and GCA and RA incidence rates. Results The correlation of GCA incidence with AL is highly significant: GCA incidence peaks 0–1 year after the AL reaches its minimum (ie, auroral electrojet reaches a maximum). The correlation of RA incidence with AL is also highly significant. RA incidence rates are lowest 5–7 years after AL reaches maximum. AL, GCA and RA incidence power spectra are similar: they have a main peak (periodicity) at about 10 years and a minor peak at 4–5 years. However, the RA incidence power spectrum main peak is broader (8–11 years), which partly explains the lower correlation between RA onset and AL. The auroral electrojets may be linked to the decline of RA incidence more strongly than the onset of RA. The incidences of RA and GCA are aligned in geomagnetic latitude. Conclusions AL and the incidences of GCA and RA all have a major periodicity of about 10 years and a secondary periodicity at 4–5 years. Geomagnetic <span class="hlt">activity</span> may explain the temporal and spatial variations, including east-west skewness in geographic coordinates, in GCA and RA incidence, although the mechanism is unknown. The link with <span class="hlt">solar</span>, geospace and atmospheric parameters need to be investigated. These novel findings warrant examination in other populations and with other autoimmune diseases. PMID:25979866</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820015734','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820015734"><span id="translatedtitle">Canopy reflectance as <span class="hlt">influenced</span> by <span class="hlt">solar</span> illumination angle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauer, M. E. (Principal Investigator); Kollenkark, J. C.; Vanderbilt, V. C.; Daughtry, C. S. T.</p> <p>1981-01-01</p> <p>The interaction of the <span class="hlt">solar</span> illumination angle and row azimuth angle of the measured reflectance factor (RF) of soybean canopies was investigated. Diurnal changes of nearly 140% were observed in the red wavelength region when canopies covered 64% of the soil. The amount of shadow observed was a function of the plant geometry and row width. As soil cover approached 100%, the diurnal changes diminished. A function tht describes the <span class="hlt">solar</span> illumination angle with respect to the row azimuth explained most of the diurnal variation in the measured RF. Variation in near infrared response was much less and did not appear to be as strongly related to Sun-row angle interactions. The near infrared/red ratio was highly sensitive to Sun angle-row direction interactions, whereas the greenness function, utilizing all four spectral bands, was not.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22126704','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22126704"><span id="translatedtitle">ASSESSING THE <span class="hlt">INFLUENCE</span> OF THE <span class="hlt">SOLAR</span> ORBIT ON TERRESTRIAL BIODIVERSITY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Feng, F.; Bailer-Jones, C. A. L.</p> <p>2013-05-10</p> <p>The terrestrial record shows a significant variation in the extinction and origination rates of species during the past half-billion years. Numerous studies have claimed an association between this variation and the motion of the Sun around the Galaxy, invoking the modulation of cosmic rays, gamma rays, and comet impact frequency as a cause of this biodiversity variation. However, some of these studies exhibit methodological problems, or were based on coarse assumptions (such as a strict periodicity of the <span class="hlt">solar</span> orbit). Here we investigate this link in more detail, using a model of the Galaxy to reconstruct the <span class="hlt">solar</span> orbit and thus a predictive model of the temporal variation of the extinction rate due to astronomical mechanisms. We compare these predictions as well as those of various reference models with paleontological data. Our approach involves Bayesian model comparison, which takes into account the uncertainties in the paleontological data as well as the distribution of <span class="hlt">solar</span> orbits consistent with the uncertainties in the astronomical data. We find that various versions of the orbital model are not favored beyond simpler reference models. In particular, the distribution of mass extinction events can be explained just as well by a uniform random distribution as by any other model tested. Although our negative results on the orbital model are robust to changes in the Galaxy model, the Sun's coordinates, and the errors in the data, we also find that it would be very difficult to positively identify the orbital model even if it were the true one. (In contrast, we do find evidence against simpler periodic models.) Thus, while we cannot rule out there being some connection between <span class="hlt">solar</span> motion and biodiversity variations on the Earth, we conclude that it is difficult to give convincing positive conclusions of such a connection using current data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.3780K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.3780K"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">Solar</span> Radiation Pressure on Satellite Surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kigel, Maryna; Bremer, Stefanie; List, Meike; Rievers, Benny; Rievers, Benny</p> <p></p> <p>In its orbit the satellite's motion is affected by several environmental disturbances. One of these disturbing effects is the <span class="hlt">solar</span> radiation pressure, which can be modeled adequately by assuming that incident radiation is absorbed, reflected specularly or/and reflected diffuse. At the German institute ZARM (Center of Applied Space Technology and Microgravity) an al-gorithm for the determination of resulting disturbance forces and torques due to <span class="hlt">solar</span> radiation pressure has been developed. The source code has been tested and compared with analytically obtained values, results will be presented. Since the <span class="hlt">solar</span> radiation pressure will be considered in the disturbance analysis of the small satellite mission MICROSCOPE, an accurate modelling of the resulting effects is necessary. Thus the algorithm has to be considered for the end-to-end simulation of this mission anyway. For these purposes a finite element model (FEM) of the MICROSCOPE satellite's surfaces structure is built, geometry and surface properties are taken from this model. First results of this study will be reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012hesa.book.....S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012hesa.book.....S"><span id="translatedtitle">Heliophysics: Evolving <span class="hlt">Solar</span> <span class="hlt">Activity</span> and the Climates of Space and Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schrijver, Carolus J.; Siscoe, George L.</p> <p>2012-01-01</p> <p>Preface; 1. Interconnectedness in heliophysics Carolus J. Schrijver and George L. Siscoe; 2. Long-term evolution of magnetic <span class="hlt">activity</span> of Sun-like stars Carolus J. Schrijver; 3. Formation and early evolution of stars and proto-planetary disks Lee W. Hartmann; 4. Planetary habitability on astronomical time scales Donald E. Brownlee; 5. <span class="hlt">Solar</span> internal flows and dynamo action Mark S. Miesch; 6. Modeling <span class="hlt">solar</span> and stellar dynamos Paul Charbonneau; 7. Planetary fields and dynamos Ulrich R. Christensen; 8. The structure and evolution of the 3D <span class="hlt">solar</span> wind John T. Gosling; 9. The heliosphere and cosmic rays J. Randy Jokipii; 10. <span class="hlt">Solar</span> spectral irradiance: measurements and models Judith L. Lean and Thomas N. Woods; 11. Astrophysical <span class="hlt">influences</span> on planetary climate systems Juerg Beer; 12. Evaluating the drivers of Earth's climate system Thomas J. Crowley; 13. Ionospheres of the terrestrial planets Stanley C. Solomon; 14. Long-term evolution of the geospace climate Jan J. Sojka; 15. Waves and transport processes in atmospheres and oceans Richard L. Walterscheid; 16. <span class="hlt">Solar</span> variability, climate, and atmospheric photochemistry Guy P. Brasseur, Daniel Marsch and Hauke Schmidt; Appendix I. Authors and editors; List of illustrations; List of tables; Bibliography; Index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046615&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dactivity%2BPhysics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046615&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dactivity%2BPhysics"><span id="translatedtitle">Long-term persistence of <span class="hlt">solar</span> <span class="hlt">activity</span>. [Abstract only</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul</p> <p>1994-01-01</p> <p>The <span class="hlt">solar</span> irradiance has been found to change by 0.1% over the recent <span class="hlt">solar</span> cycle. A change of irradiance of about 0.5% is required to effect the Earth's climate. How frequently can a variation of this size be expected? We examine the question of the persistence of non-periodic variations in <span class="hlt">solar</span> <span class="hlt">activity</span>. The Huerst exponent, which characterizes the persistence of a time series (Mandelbrot and Wallis, 1969), is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD (Stuiver and Pearson, 1986). We find a constant Huerst exponent, suggesting that <span class="hlt">solar</span> <span class="hlt">activity</span> in the frequency range of from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately equal to 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process (Ruzmaikin et al., 1992), and that is is the same type of process over a wide range of time interval lengths. We conclude that the time period over which an irradiance change of 0.5% can be expected to occur is significantly shorter than that which would be expected for variations produced by a white-noise process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850051379&hterms=modulation+transfer+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmodulation%2Btransfer%2Bfunction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850051379&hterms=modulation+transfer+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmodulation%2Btransfer%2Bfunction"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> and modulation of the cosmic ray intensity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akasofu, S.-I.; Olmsted, C.; Lockwood, J. A.</p> <p>1985-01-01</p> <p>Since its discovery by Forbush (1954), the 11-year cycle modulation of the cosmic ray intensity has been studied extensively. Bowe and Hatton (1982) obtained a well-behaved transfer function F between the <span class="hlt">solar</span> <span class="hlt">activity</span> S and the cosmic ray intensity modulation Io-I. They suggested that the 11-year variation for sunspot cycle 20 can be attributed to the modulating effect of <span class="hlt">solar</span> flare-induced shocks propagating through the heliosphere. The cosmic ray intensity in the absence of <span class="hlt">solar</span> <span class="hlt">activity</span> is denoted by Io, while I denotes the observed intensity. Bowe and Hatton infer that the boundary of the heliosphere is located at a distance of 70-90 AU. Since their conclusion is of great importance in understanding the mechanism of the 11-year modulation, the present investigation is concerned with a repetition of their study for two cycles, taking into account the use of a slightly modified method. The obtained results confirm the conclusions reached by Bowe and Hatton that there is a well-behaved transfer function for <span class="hlt">solar</span> flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JSWSC...3A..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JSWSC...3A..06K"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> impact on the Earth's upper atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kutiev, Ivan; Tsagouri, Ioanna; Perrone, Loredana; Pancheva, Dora; Mukhtarov, Plamen; Mikhailov, Andrei; Lastovicka, Jan; Jakowski, Norbert; Buresova, Dalia; Blanch, Estefania; Andonov, Borislav; Altadill, David; Magdaleno, Sergio; Parisi, Mario; Miquel Torta, Joan</p> <p>2013-02-01</p> <p>The paper describes results of the studies devoted to the <span class="hlt">solar</span> <span class="hlt">activity</span> impact on the Earth's upper atmosphere and ionosphere, conducted within the frame of COST ES0803 Action. Aim: The aim of the paper is to represent results coming from different research groups in a unified form, aligning their specific topics into the general context of the subject. Methods: The methods used in the paper are based on data-driven analysis. Specific databases are used for spectrum analysis, empirical modeling, electron density profile reconstruction, and forecasting techniques. Results: Results are grouped in three sections: Medium- and long-term ionospheric response to the changes in <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span>, storm-time ionospheric response to the <span class="hlt">solar</span> and geomagnetic forcing, and modeling and forecasting techniques. Section 1 contains five subsections with results on 27-day response of low-latitude ionosphere to <span class="hlt">solar</span> extreme-ultraviolet (EUV) radiation, response to the recurrent geomagnetic storms, long-term trends in the upper atmosphere, latitudinal dependence of total electron content on EUV changes, and statistical analysis of ionospheric behavior during prolonged period of <span class="hlt">solar</span> <span class="hlt">activity</span>. Section 2 contains a study of ionospheric variations induced by recurrent CIR-driven storm, a case-study of polar cap absorption due to an intense CME, and a statistical study of geographic distribution of so-called E-layer dominated ionosphere. Section 3 comprises empirical models for describing and forecasting TEC, the F-layer critical frequency foF2, and the height of maximum plasma density. A study evaluates the usefulness of effective sunspot number in specifying the ionosphere state. An original method is presented, which retrieves the basic thermospheric parameters from ionospheric sounding data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeoRL..38.6701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoRL..38.6701S"><span id="translatedtitle">The minimal <span class="hlt">solar</span> <span class="hlt">activity</span> in 2008-2009 and its implications for long-term climate modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schrijver, C. J.; Livingston, W. C.; Woods, T. N.; Mewaldt, R. A.</p> <p>2011-03-01</p> <p>Variations in the total <span class="hlt">solar</span> irradiance (TSI) associated with <span class="hlt">solar</span> <span class="hlt">activity</span> have been argued to <span class="hlt">influence</span> the Earth's climate system, in particular when <span class="hlt">solar</span> <span class="hlt">activity</span> deviates from the average for a substantial period. One such example is the 17th Century Maunder Minimum during which sunspot numbers were extremely low, as Earth experienced the Little Ice Age. Estimation of the TSI during that period has relied on extrapolations of correlations with sunspot numbers or even more indirectly with modulations of galactic cosmic rays. We argue that there is a minimum state of <span class="hlt">solar</span> magnetic <span class="hlt">activity</span> associated with a population of relatively small magnetic bipoles which persists even when sunspots are absent, and that consequently estimates of TSI for the Little Ice Age that are based on scalings with sunspot numbers are generally too low. The minimal <span class="hlt">solar</span> <span class="hlt">activity</span>, which measurements show to be frequently observable between <span class="hlt">active</span>-region decay products regardless of the phase of the sunspot cycle, was approached globally after an unusually long lull in sunspot <span class="hlt">activity</span> in 2008-2009. Therefore, the best estimate of magnetic <span class="hlt">activity</span>, and presumably TSI, for the least-<span class="hlt">active</span> Maunder Minimum phases appears to be provided by direct measurement in 2008-2009. The implied marginally significant decrease in TSI during the least <span class="hlt">active</span> phases of the Maunder Minimum by 140 to 360 ppm relative to 1996 suggests that drivers other than TSI dominate Earth's long-term climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMPP21B1912K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMPP21B1912K"><span id="translatedtitle">Pervasive <span class="hlt">solar</span> <span class="hlt">influence</span> on Greenland temperature over the past 4000 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobashi, T.; Azuma, K. G.; Box, J. E.; Gao, C.; Nakaegawa, T.</p> <p>2013-12-01</p> <p>During the past decades, Greenland climate has undergone rapid warming and ice sheet ablation in coastal region with a nearly 1 mm/y sea level contribution. For sea level projection, it is critical to understand the mechanisms of Greenland temperature variability. Greenland temperature is known to be affected by the North Atlantic Oscillation (NAO), and it is also highly correlated with North Atlantic average temperature. Using the reconstructed Greenland temperature from argon and nitrogen isotopes in occluded air in GISP2 ice core (Kobashi et al., 2011), we found Greenland temperature deviated negatively (positively) from North Hemispheric (NH) temperature trend during stronger (weaker) <span class="hlt">solar</span> <span class="hlt">activity</span> over the past 800 years (Kobashi et al., 2013). Climate modeling suggests that the deviation was caused by <span class="hlt">solar</span> induced atmospheric circulation changes (like NAO). The model also suggests that Atlantic meridional circulation weakens during the stronger sun by similar processes as enhanced greenhouse effect (Kobashi et al., 2013). For the past 4000 years, we reconstructed northern NH temperature using a 1-dimensional energy balance model with reconstructed climate forcing (volcanic, <span class="hlt">solar</span>, greenhouse gas, orbital forcings). The model exhibits a clear cooling trend over the past 4000 years as observed for the reconstructed Greenland temperature through decreasing annual average insolation. Considering the negative <span class="hlt">solar</span> <span class="hlt">influence</span> on Greenland temperature, the modeled and observed Greenland temperatures agree with correlation coefficients of r = 0.34-0.36, p = 0.1-0.04 in a multidecadal time scale (21-yr RMs) and r = 0.38-0.45, p = 0.1-0.05 in a centennial time scale (101-yr RMs), explaining 14% to 20% of variance of observed temperature in multidecadal to centennial time scales with a 90-96% confidence interval. This is smaller than 25% for European winter and spring temperatures, or 35% for annual temperatures in 11 yr smoothed data over the past five centuries</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050070874','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050070874"><span id="translatedtitle">The October-November, 2003 <span class="hlt">Solar</span> <span class="hlt">Activity</span> and its Relationship to the "approximately 155 day" <span class="hlt">Solar</span> Periodicity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2005-01-01</p> <p>Periodicities of - 155 days in various <span class="hlt">solar</span> and interplanetary phenomena were first discovered during <span class="hlt">solar</span> cycle 21 and have been shown t o be intermittently present in other <span class="hlt">solar</span> cycles. In the current <span class="hlt">solar</span> cycle (23), they have been reported in <span class="hlt">solar</span> energetic particle events and interplanetary coronal maSS ejections. We assess whether the "unexpected" October - November 2003 burst of <span class="hlt">solar</span> <span class="hlt">activity</span> during the late declining phase of the cycle may have been a manifestation of such a periodic behavior, and hence might have been to =me extent "predictable". If the pattern were to continue, episodes of enhanced <span class="hlt">activity</span> might be expected around April - May and October, 2004. There was a mod- est increase <span class="hlt">activity</span> increase in mid-April, 2004 which may conform to this pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171438','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171438"><span id="translatedtitle">The October-November, 2003 <span class="hlt">Solar</span> <span class="hlt">Activity</span> and its Relationship to the "approx. 155 day" <span class="hlt">Solar</span> Periodicity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2004-01-01</p> <p>Periodicities of approx. 155 days in various <span class="hlt">solar</span> and interplanetary phenomena were first discovered during <span class="hlt">solar</span> cycle 21 and have been shown to be intermittently present in other <span class="hlt">solar</span> cycles. In the current <span class="hlt">solar</span> cycle (23), they have been reported in <span class="hlt">solar</span> energetic particle events and interplanetary coronal mass ejections. We assess whether the "unexpected" October - November 2003 burst of <span class="hlt">solar</span> <span class="hlt">activity</span> during the late declining phase of the cycle may have been a manifestation of such a periodic behavior, and hence might have been to some extent "predictable". If the pattern were to continue, episodes of enhanced <span class="hlt">activity</span> might be expected around April - May and October, 2004. There was a modest increase <span class="hlt">activity</span> increase in mid-April, 2004 which may conform to this pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5019846','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5019846"><span id="translatedtitle">Summary of <span class="hlt">solar</span> <span class="hlt">activity</span> observed at the Mauna Loa <span class="hlt">Solar</span> Observatory: 1980-1983. Technical note</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rock, K.; Fisher, R.; Garcia, C.; Yasukawa, E.</p> <p>1983-11-01</p> <p>The following technical note summarizes <span class="hlt">solar</span> <span class="hlt">activity</span> observed during the first four years operation of the experiment systems of the Coronal Dynamics Project, which are located at the Mauna Loa <span class="hlt">Solar</span> Observatory. This short report has been produced with the general aim of providing users of Mauna Loa observations with a summary of data for specific events. So that this table might be as useful as possible, a comprehensive review of three sources was performed. The plain language logs, identified as the so-called observer's logs, the now-discontinued <span class="hlt">activity</span> logs, and the prominence monitor quality control logs were the sources from which the information in the following tables was obtained. It is expected that this review will be of particular use to those investigators who intend to use both the K-coronameter data base and the SMM Coronagraph-Polarimeter data for the study of coronal transient events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040182245&hterms=ssi&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dssi','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040182245&hterms=ssi&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dssi"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Activity</span> and its Impact on Earth's Climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cahalan, Robert F.</p> <p>2004-01-01</p> <p>The Sun's <span class="hlt">activity</span> is now approaching an expected 2006 minimum, following the dramatic maximum of <span class="hlt">Solar</span> Cycle 23, that included events such as the 2001 "Bastille Day" Coronal Mass Ejection, and the record-setting Oct-Nov 2003 <span class="hlt">solar</span> flares, with their associated sunspots and variations in Total <span class="hlt">Solar</span> Irradiance, or TSI. On Nov 4,2003 the largest X-ray flare ever detected (X-28) was observed in detail. We discuss recent satellite measurements of TSI by ACRIM 2 and 3 and Virgo, and new precision observations of TSI and SSI (<span class="hlt">Solar</span> Spectral Irradiance) from the SORCE mission, that launched on January 25,2003. TSI variations recorded during the June 8,2004 transit of Venus show the unprecedented precision of the SORCE Total Irradiance Monitor (TIM) instrument, the first of its kind to employ phase-sensitive detection. The SORCE spectral instruments, XPS, Solstice, and SIM, record the Sun's changes over a wide range of wavelengths, from 1 to more than 2000 nanometers, for the first time covering the peak of the <span class="hlt">solar</span> spectrum, including spectral components that provide energy inputs to key components of the climate system - ultraviolet (UV) into the upper atmospheric ozone layer, infrared (IR) into the lower atmosphere and clouds, and Visible into the Oceans and biosphere. Succeeding satellite missions are planned to monitor both TSI and SSI through Cycle 24. We summarize current ideas about decadal and longer <span class="hlt">solar</span> variability, and associated potential impacts on Earth's climate on time scales from decades to centuries, especially highlighting the role of feedbacks in the climate system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMPP33A2109E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMPP33A2109E"><span id="translatedtitle">Centennial Scale Variations in Lake Productivity Linked to <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Englebrecht, A.; Bhattacharyya, S.; Guilderson, T. P.; Ingram, L.; Byrne, R.</p> <p>2012-12-01</p> <p><span class="hlt">Solar</span> variations on both decadal and centennial timescales have been associated with climate phenomena (van Loon et al., 2004; Hodell et al., 2001; White et al., 1997). The energy received by the Earth at the peak of the <span class="hlt">solar</span> cycle increases by <0.1%; so the question has remained of how this could be amplified to produce an observable climate response. Recent modeling shows that the response of the Earth's climate system to the 11-year <span class="hlt">solar</span> cycle may be amplified through stratosphere and ocean feedbacks and has the potential to impact climate variability on a multidecadal to centennial timescales (Meehl et al., 2009). Here, we report a 1000-year record of changes in the stratigraphy and carbon isotope composition of varved lake sediment from Isla Isabela (22°N, 106°W) in the subtropical northeast Pacific. Stable carbon isotopes and carbonate stratigraphy can be used to infer surface productivity in the lake. Our analysis shows variations in primary productivity on centennial timescales and suggests that <span class="hlt">solar</span> <span class="hlt">activity</span> may be an important component of Pacific climate variability. A possible response during <span class="hlt">solar</span> maxima acts to keep the eastern equatorial Pacific cooler and drier than usual, producing conditions similar to a La Niña event. In the region around Isla Isabela peak <span class="hlt">solar</span> years were characterized by decreased surface temperatures and suppressed precipitation (Meehl et al., 2009), which enhance productivity at Isabela (Kienel et al. 2011). In the future, we plan to analyze the data using advanced time series analysis techniques like the wavelets together with techniques to handle irregularly spaced time series data. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-571672</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.8730V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.8730V"><span id="translatedtitle">Trends of <span class="hlt">solar</span>-geomagnetic <span class="hlt">activity</span>, cosmic rays, atmosphere, and climate changes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voronin, N.; Avakyan, S.</p> <p>2009-04-01</p> <p>The results are presented of the analysis of trends in the <span class="hlt">solar</span>-geomagnetic <span class="hlt">activity</span> and intensity of galactic cosmic rays (GCR) for the several eleven-year <span class="hlt">solar</span> cycles. The indication has been revealed of the change of signs in the long-term changes in geomagnetic <span class="hlt">activity</span> (aa-index) and the GCR in recent years. These changes correspond to the changes of sings in long-term trends in some of atmospheric parameters (transparency, albedo, cloudness, the content of water vapour, methane, ozone, the erythemal radiation flux). These global changes in atmosphere is most important problem of the up-to-date science. The global warming observed during the several past decades presents a real danger for the mankind. Till present the predominant point of view has been that the main cause of the increase of mean surface air temperature is the increase of concentrations of the anthropogenic gases first of all carbon dioxide CO2 and methane CH_4. Indeed, from the beginning of nineteen century the concentration of CO2 in the atmosphere has been growing and now it exceeds the initial level by the factor of 1.4 and the speed of this increase being growing too. This was the reason of international efforts to accept the Kyoto Protocol which limited the ejections of greenhouse gases. However there are premises which show that the <span class="hlt">influence</span> of <span class="hlt">solar</span> variability on the climate should be taken into account in the first place. The obtained results are analyzed from the point of view of well known effects of GCR <span class="hlt">influence</span> on weather and climate with taken into account also a novel trigger mechanism in <span class="hlt">solar</span>-terrestrial relations what allows revaluation of the role of <span class="hlt">solar</span> flares and geomagnetic storms. The mechanism explains how agents of <span class="hlt">solar</span> and geomagnetic <span class="hlt">activities</span> affect atmospheric processes. This first agent under consideration is variation of fluxes of <span class="hlt">solar</span> EUV and X-ray radiation. The second agent is fluxes of electrons and protons which precipitate from radiation belts as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/95979','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/95979"><span id="translatedtitle">Fluctuations of the Caspian Sea level in the quasi-two-year and 11-year cycles of <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nuzhdina, M.A.</p> <p>1995-07-01</p> <p>Fluctuations of the Caspian Sea level due to dynamics of <span class="hlt">solar</span> <span class="hlt">activity</span> in its quasi-two-year and 11-year cycles, as well as to the <span class="hlt">influence</span> of the 22-to 23-year magnetic cycle are analyzed. Perturbation of the geomagnetic field and the atmospheric circulation are regarded as a transmitting mechanism of the Sun`s <span class="hlt">influence</span> on the Earth`s hydrosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120014296','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120014296"><span id="translatedtitle">The <span class="hlt">Influence</span> of Large <span class="hlt">Solar</span> Proton Events on the Atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jackman, Charles H.</p> <p>2012-01-01</p> <p><span class="hlt">Solar</span> proton events (SPEs) can cause changes in constituents in the Earth s polar middle atmosphere. A number of large SPEs have occurred over the past 50 years and tend to happen most frequently near <span class="hlt">solar</span> maximum. The highly energetic protons cause ionizations, excitations, dissociations, and dissociative ionizations of the background constituents. Complicated ion chemistry leads to HOx (H, OH, HO2) production and dissociation of N2 leads to NOy (N, NO, NO2, NO3, N2O5, HNO3, HO2NO2, ClONO2, BrONO2) production. Both the HOx and NOy increases can result in changes to ozone in the stratosphere and mesosphere. The HOx increases lead to short-lived (days) ozone decreases in the mesosphere and upper stratosphere. The NOy increases lead to long-lived (several months) stratospheric ozone changes because of the long lifetime of NOy constituents in this region. UARS HALogen Occultation Experiment (HALOE) instrument observations showed SPE-caused polar stratospheric NOx (NO+NO2) increases over 10 ppbv in September 2000 due to the very large SPE of July 2000, which are reasonably well simulated with the Whole Atmosphere Community Climate Model (WACCM). WACCM-computed SPE-caused polar stratospheric ozone decreases >10% continued for up to 5 months past the largest events in the past 50 years, however, SPE-caused total ozone changes were not found to be statistically significant. Small polar middle atmospheric temperature changes of <4 K have also been predicted to occur as a result of the larger SPEs. The polar atmospheric effects of large SPEs during <span class="hlt">solar</span> cycle 23 and 24 will be emphasized in this presentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988BAICz..39....8B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988BAICz..39....8B"><span id="translatedtitle"><span class="hlt">Solar</span> flare <span class="hlt">activity</span> changes and global magnetic field disturbances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bumba, V.; Hejna, L.</p> <p>1988-01-01</p> <p>Published observational data on <span class="hlt">solar</span>-flare <span class="hlt">activity</span> in the period 1965-1980 are analyzed statistically and related to changes in the magnetic <span class="hlt">active</span> longitudes (MALs) identified and studied by Bumba and Hejna (1986). MALs are long strips of single-polarity fields which may persist for about 8-30 rotations and display internal structure. The data sets employed are briefly characterized, and the results are presented graphically. Flare maxima are found to correlate well with MAL disturbances, especially during the ascending phase of the <span class="hlt">solar</span> cycle and with MALs of negative polarity. The possible implications of these findings for the interplanetary magnetic field and for theoretical models of flare generation are indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270640','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270640"><span id="translatedtitle">GRAND MINIMA AND NORTH-SOUTH ASYMMETRY OF <span class="hlt">SOLAR</span> <span class="hlt">ACTIVITY</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Olemskoy, S. V.; Kitchatinov, L. L.</p> <p>2013-11-01</p> <p>A <span class="hlt">solar</span>-type dynamo model in a spherical shell is developed with allowance for random dependence of the poloidal field generation mechanism on time and latitude. The model shows repeatable epochs of a strongly decreased amplitude of magnetic cycles similar to the Maunder minimum of <span class="hlt">solar</span> <span class="hlt">activity</span>. Random dependence of dynamo parameters on latitude breaks the equatorial symmetry of generated fields. The model shows the correlation of the occurrence of grand minima with deviations in the dynamo field from dipolar parity. An increased north-south asymmetry of magnetic <span class="hlt">activity</span> can, therefore, be an indicator of transitions to grand minima. Qualitative interpretation of this correlation is suggested. Statistics of grand minima in the model are close to the Poisson random process, indicating that the onset of a grand minimum is statistically independent of preceding minima.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..914E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..914E"><span id="translatedtitle">Longitudinal structure of <span class="hlt">solar</span> <span class="hlt">activity</span>: Regular and stochastic behavior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Erofeev, D. V.</p> <p>2015-12-01</p> <p>The ratio of regular and stochastic components in the behavior of the longitudinal-temporal distribution of <span class="hlt">solar</span> <span class="hlt">activity</span> is studied with the use of correlation and spectral analysis of data on sunspot groups for 12 <span class="hlt">solar</span> cycles. It was found that data samples of about 10 years in length often (in 50% of cases) show the presence of regular structures in the longitudinal distribution of sunspot groups. However, these structures are nonstationary; their characteristic scales and rotation periods vary when changing from one 10-year interval to another. The behavior of the longitudinal structure of sunspot <span class="hlt">activity</span> is mainly stochastic on a long time scale (50-100 years); it is characterized by a wide spectrum of spatial scales and a continuous spectrum of rotation periods, which takes a period from 25.6 to 28.5 days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SoPh..260..451J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SoPh..260..451J"><span id="translatedtitle">Study of Distribution and Asymmetry of <span class="hlt">Solar</span> <span class="hlt">Active</span> Prominences during <span class="hlt">Solar</span> Cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Navin Chandra; Bankoti, Neeraj Singh; Pande, Seema; Pande, Bimal; Pandey, Kavita</p> <p>2009-12-01</p> <p>In this article we present the results of a study of the spatial distribution and asymmetry of <span class="hlt">solar</span> <span class="hlt">active</span> prominences (SAP) for the period 1996 through 2007 (<span class="hlt">solar</span> cycle 23). For more meaningful statistical analysis we analyzed the distribution and asymmetry of SAP in two subdivisions viz. Group1 (ADF, APR, DSF, CRN, CAP) and Group2 (AFS, ASR, BSD, BSL, DSD, SPY, LPS). The North - South (N - S) latitudinal distribution shows that the SAP events are most prolific in the 21° to 30° slice in the Northern and Southern Hemispheres; the East - West (E - W) longitudinal distribution study shows that the SAP events are most prolific (best observable) in the 81° to 90° slice in the Eastern and Western Hemispheres. It was found that the SAP <span class="hlt">activity</span> during this cycle is low compared to previous <span class="hlt">solar</span> cycles. The present study indicates that during the rising phase of the cycle the number of SAP events are roughly equal in the Northern and Southern Hemispheres. However, <span class="hlt">activity</span> in the Southern Hemisphere has been dominant since 1999. Our statistical study shows that the N - S asymmetry is more significant then the E - W asymmetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22004456','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22004456"><span id="translatedtitle"><span class="hlt">INFLUENCE</span> OF THE AMBIENT <span class="hlt">SOLAR</span> WIND FLOW ON THE PROPAGATION BEHAVIOR OF INTERPLANETARY CORONAL MASS EJECTIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Temmer, Manuela; Rollett, Tanja; Moestl, Christian; Veronig, Astrid M.; Vrsnak, Bojan; Odstrcil, Dusan</p> <p>2011-12-20</p> <p>We study three coronal mass ejection (CME)/interplanetary coronal mass ejection (ICME) events (2008 June 1-6, 2009 February 13-18, and 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of <span class="hlt">Solar</span> Terrestrial Relations Observatory Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propagation in interplanetary (IP) space that is governed by two forces: the propelling Lorentz force and the drag force. We address the question: which heliospheric distance range does the drag become dominant and the CME adjust to the <span class="hlt">solar</span> wind flow. To this end, we analyze speed differences between ICMEs and the ambient <span class="hlt">solar</span> wind flow as a function of distance. The evolution of the ambient <span class="hlt">solar</span> wind flow is derived from ENLIL three-dimensional MHD model runs using different <span class="hlt">solar</span> wind models, namely, Wang-Sheeley-Arge and MHD-Around-A-Sphere. Comparing the measured CME kinematics with the <span class="hlt">solar</span> wind models, we find that the CME speed becomes adjusted to the <span class="hlt">solar</span> wind speed at very different heliospheric distances in the three events under study: from below 30 R{sub Sun }, to beyond 1 AU, depending on the CME and ambient <span class="hlt">solar</span> wind characteristics. ENLIL can be used to derive important information about the overall structure of the background <span class="hlt">solar</span> wind, providing more reliable results during times of low <span class="hlt">solar</span> <span class="hlt">activity</span> than during times of high <span class="hlt">solar</span> <span class="hlt">activity</span>. The results from this study enable us to obtain greater insight into the forces acting on CMEs over the IP space distance range, which is an important prerequisite for predicting their 1 AU transit times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...743..101T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...743..101T"><span id="translatedtitle"><span class="hlt">Influence</span> of the Ambient <span class="hlt">Solar</span> Wind Flow on the Propagation Behavior of Interplanetary Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Temmer, Manuela; Rollett, Tanja; Möstl, Christian; Veronig, Astrid M.; Vršnak, Bojan; Odstrčil, Dusan</p> <p>2011-12-01</p> <p>We study three coronal mass ejection (CME)/interplanetary coronal mass ejection (ICME) events (2008 June 1-6, 2009 February 13-18, and 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of <span class="hlt">Solar</span> Terrestrial Relations Observatory Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propagation in interplanetary (IP) space that is governed by two forces: the propelling Lorentz force and the drag force. We address the question: which heliospheric distance range does the drag become dominant and the CME adjust to the <span class="hlt">solar</span> wind flow. To this end, we analyze speed differences between ICMEs and the ambient <span class="hlt">solar</span> wind flow as a function of distance. The evolution of the ambient <span class="hlt">solar</span> wind flow is derived from ENLIL three-dimensional MHD model runs using different <span class="hlt">solar</span> wind models, namely, Wang-Sheeley-Arge and MHD-Around-A-Sphere. Comparing the measured CME kinematics with the <span class="hlt">solar</span> wind models, we find that the CME speed becomes adjusted to the <span class="hlt">solar</span> wind speed at very different heliospheric distances in the three events under study: from below 30 R ⊙, to beyond 1 AU, depending on the CME and ambient <span class="hlt">solar</span> wind characteristics. ENLIL can be used to derive important information about the overall structure of the background <span class="hlt">solar</span> wind, providing more reliable results during times of low <span class="hlt">solar</span> <span class="hlt">activity</span> than during times of high <span class="hlt">solar</span> <span class="hlt">activity</span>. The results from this study enable us to obtain greater insight into the forces acting on CMEs over the IP space distance range, which is an important prerequisite for predicting their 1 AU transit times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20930841','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20930841"><span id="translatedtitle">An <span class="hlt">influence</span> of <span class="hlt">solar</span> spectral variations on radiative forcing of climate.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haigh, Joanna D; Winning, Ann R; Toumi, Ralf; Harder, Jerald W</p> <p>2010-10-01</p> <p>The thermal structure and composition of the atmosphere is determined fundamentally by the incoming <span class="hlt">solar</span> irradiance. Radiation at ultraviolet wavelengths dissociates atmospheric molecules, initiating chains of chemical reactions-specifically those producing stratospheric ozone-and providing the major source of heating for the middle atmosphere, while radiation at visible and near-infrared wavelengths mainly reaches and warms the lower atmosphere and the Earth's surface. Thus the spectral composition of <span class="hlt">solar</span> radiation is crucial in determining atmospheric structure, as well as surface temperature, and it follows that the response of the atmosphere to variations in <span class="hlt">solar</span> irradiance depends on the spectrum. Daily measurements of the <span class="hlt">solar</span> spectrum between 0.2 µm and 2.4 µm, made by the Spectral Irradiance Monitor (SIM) instrument on the <span class="hlt">Solar</span> Radiation and Climate Experiment (SORCE) satellite since April 2004, have revealed that over this declining phase of the <span class="hlt">solar</span> cycle there was a four to six times larger decline in ultraviolet than would have been predicted on the basis of our previous understanding. This reduction was partially compensated in the total <span class="hlt">solar</span> output by an increase in radiation at visible wavelengths. Here we show that these spectral changes appear to have led to a significant decline from 2004 to 2007 in stratospheric ozone below an altitude of 45 km, with an increase above this altitude. Our results, simulated with a radiative-photochemical model, are consistent with contemporaneous measurements of ozone from the Aura-MLS satellite, although the short time period makes precise attribution to <span class="hlt">solar</span> effects difficult. We also show, using the SIM data, that <span class="hlt">solar</span> radiative forcing of surface climate is out of phase with <span class="hlt">solar</span> <span class="hlt">activity</span>. Currently there is insufficient observational evidence to validate the spectral variations observed by SIM, or to fully characterize other <span class="hlt">solar</span> cycles, but our findings raise the possibility that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Msngr.164...10M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Msngr.164...10M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Activity</span>-driven Variability of Instrumental Data Quality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martayan, C.; Smette, A.; Hanuschik, R.; van Der Heyden, P.; Mieske, S.</p> <p>2016-06-01</p> <p>The unexplained variability of the data quality from Very Large Telescope instruments and the frequency of power cuts have been investigated. Origins for the variability in ambient temperature variations, software, data reduction pipelines and internal to hardware could be discarded. The most probable cause appears to be correlated with the evolution of the cosmic ray rate, and also with <span class="hlt">solar</span> and terrestrial geomagnetic <span class="hlt">activity</span>. We report on the consequences of such variability and describe how the observatory infrastructure, instruments and data are affected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20050092346&hterms=albedo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dalbedo','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20050092346&hterms=albedo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dalbedo"><span id="translatedtitle">Correlation of Far Ultraviolet Lunar Albedo with <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maddox, Will; Spann, James F.; Germany, Glynn</p> <p>2004-01-01</p> <p>We present a correlative analysis between the variability of the lunar albedo in the far ultraviolet wavelength range (130- 190 nm) and various <span class="hlt">solar</span> <span class="hlt">activity</span> indices for a two-week period. We also report lunar albedo measurements in four separate wavelength ranges, corresponding to four filters on the Polar Ultraviolet Imager. To our knowledge this is the first reported long term measurements of the lunar albedo in this wavelength range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995AdSpR..16R.153S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995AdSpR..16R.153S"><span id="translatedtitle">Magnetic observations during the recent declining phase of <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, E. J.</p> <p></p> <p>Changes in the heliospheric magnetic field during the recent declining phase in <span class="hlt">solar</span> <span class="hlt">activity</span> are reviewed and compared with observations during past sunspot cycles. The study is based principally on data obtained by IMP-8 and Ulysses. The field magnitude is found to have increased during the declining phase until it reached a maximum value of 11.5nT in approximately 1991.5, approximately two years after sunspot maximum. The field of the sun's south pole became negative after a reversal in early 1990. The sector structure disappeared at Ulysses in April 1993 when the latitude of the spacecraft was -30 deg revealing a low inclination of the heliospheric current sheet. A large outburst of <span class="hlt">solar</span> <span class="hlt">activity</span> in March 1991 caused four Coronal Mass Ejections (CMEs) and numerious shocks at the location of Ulysses. Following a delay of more than a year, a series of recurrent high speed streams and Corotating Interaction Regions commenced in July 1992 which were observed by IMP-8, Ulysses and Voyager 2. In all these respects, the behavior of the magnetic field mimics that seen in the two earlier sunspot cycles. The comprehensive data set suggests a correlation between the absolute value of B and sunspot number. The major <span class="hlt">solar</span> cycle variations in the radial component (and magnitude) of the field have been successfully reproduced by a recent model consisting of a tilted <span class="hlt">solar</span> dipole, whose strength and tilt undergo characteristic changes over the sunspot cycle, and the heliospheric current sheet. The large outbursts of <span class="hlt">activity</span> in mid-1972, mid-1982 and the first quarter of 1991 may represent a characteristic last 'gasp' of <span class="hlt">solar</span> <span class="hlt">activity</span> before the sun evolves to a different state. The recurrent high speed streams in 1973, 1984 and 1992 accompany the developemnt of large asymetrical polar coronal holes and the growth in intensity of the polar cap fields. After they endure for about one year, the polar coronal holes recede and the high speed streams are replaced by weaker</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950052992&hterms=Magnetic+reversal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2Breversal','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950052992&hterms=Magnetic+reversal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2Breversal"><span id="translatedtitle">Magnetic observations during the recent declining phase of <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, E. J.</p> <p>1995-01-01</p> <p>Changes in the heliospheric magnetic field during the recent declining phase in <span class="hlt">solar</span> <span class="hlt">activity</span> are reviewed and compared with observations during past sunspot cycles. The study is based principally on data obtained by IMP-8 and Ulysses. The field magnitude is found to have increased during the declining phase until it reached a maximum value of 11.5nT in approximately 1991.5, approximately two years after sunspot maximum. The field of the sun's south pole became negative after a reversal in early 1990. The sector structure disappeared at Ulysses in April 1993 when the latitude of the spacecraft was -30 deg revealing a low inclination of the heliospheric current sheet. A large outburst of <span class="hlt">solar</span> <span class="hlt">activity</span> in March 1991 caused four Coronal Mass Ejections (CMEs) and numerious shocks at the location of Ulysses. Following a delay of more than a year, a series of recurrent high speed streams and Corotating Interaction Regions commenced in July 1992 which were observed by IMP-8, Ulysses and Voyager 2. In all these respects, the behavior of the magnetic field mimics that seen in the two earlier sunspot cycles. The comprehensive data set suggests a correlation between the absolute value of B and sunspot number. The major <span class="hlt">solar</span> cycle variations in the radial component (and magnitude) of the field have been successfully reproduced by a recent model consisting of a tilted <span class="hlt">solar</span> dipole, whose strength and tilt undergo characteristic changes over the sunspot cycle, and the heliospheric current sheet. The large outbursts of <span class="hlt">activity</span> in mid-1972, mid-1982 and the first quarter of 1991 may represent a characteristic last 'gasp' of <span class="hlt">solar</span> <span class="hlt">activity</span> before the sun evolves to a different state. The recurrent high speed streams in 1973, 1984 and 1992 accompany the developemnt of large asymetrical polar coronal holes and the growth in intensity of the polar cap fields. After they endure for about one year, the polar coronal holes recede and the high speed streams are replaced by weaker</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/663266','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/663266"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span>-probe inherent atmosphere on in-situ observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hassanein, A.; Konkashbaev, A.I.; Konkashbaev, I.K.; Nikandrov, L.B.</p> <p>1998-08-01</p> <p>The <span class="hlt">solar</span> corona is the source of the <span class="hlt">solar</span> wind, which is responsible for the heliosphere and plays a crucial role in <span class="hlt">solar</span>/terrestrial phenomena. A comprehensive understanding of these phenomena can be established only by directly measuring ion and electron velocity distributions, plasma waves, and fluxes of energetic particles near the sun. The problem resulting from the inherent atmosphere of a spacecraft moving in the vicinity of the sun and the <span class="hlt">influence</span> of this atmosphere on in-situ measurements of the <span class="hlt">solar</span> corona plasma is key to the realization and success of any <span class="hlt">solar</span> probe mission. To evaluate the <span class="hlt">influence</span> of the probe-inherent atmosphere on in-situ observations, the authors have developed comprehensive radiation hydrodynamic models. The physics of plasma/probe/vapor interaction are also being developed in a self-consistent model to predict the effect of probe inherent atmosphere on in-situ measurements of corona parameters during <span class="hlt">solar</span> flares. Interaction of the ionized atmosphere with the ambient natural plasma will create a turbulent shock wave that can affect in-situ measurements and must be taken into account in designing the spacecraft and its scientific components.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM31E4249R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM31E4249R"><span id="translatedtitle">Dayside Auroral <span class="hlt">Activity</span> During <span class="hlt">Solar</span> Maximum and Minimum Periods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rawie, M.; Fasel, G. J.; Flicker, J.; Angelo, A.; Bender, S.; Alyami, M.; Sibeck, D. G.; Sigernes, F.; Lorentzen, D. A.; Green, D.</p> <p>2014-12-01</p> <p>It is well documented that the dayside auroral oval shifts equatorward when the interplanetary magnetic field (IMF) Bz-component turns southward [Burch, 1973; Akasofu, 1977; Horwitz and Akasofu, 1977; Sandholt et al., 1986, 1988]. During these periods of oval expansion dayside transients are observed to move away from the poleward edge of the auroral oval and drift poleward. These poleward-moving auroral forms are believed to be ionospheric signatures of dayside merging. The dayside auroral oval usually begins to contract when the interplanetary magnetic field turns sharply northward, Bz>0. Eighteen years of meridian scanning photometer (MSP) data from the Kjell Henriksen Observatory in Longyearbyen, Norway are analyzed. During the boreal winter the Sun is several degrees below the horizon. This permits optical observations throughout the daytime period. The MSP Data is selected two hours before and after local noon in Longyearbeyn. <span class="hlt">Solar</span> wind data (<span class="hlt">solar</span> wind pressure and speed, along with the IMF Bx, By, Bz components) are collected for each interval and combined with the MSP observations. This data is then separated using <span class="hlt">solar</span> maximum and minimum periods. Auroral <span class="hlt">activity</span> (oval expansions and contractions along with the frequency and number of poleward-moving auroral forms) is documented for both <span class="hlt">solar</span> maximum and minimum periods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E.792H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E.792H&link_type=ABSTRACT"><span id="translatedtitle">Forecasting the Peak of the Present <span class="hlt">Solar</span> <span class="hlt">Activity</span> Cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamid, Rabab; Marzouk, Beshir</p> <p>2016-07-01</p> <p><span class="hlt">Solar</span> forecasting of the level of sun <span class="hlt">Activity</span> is very important subject for all space programs. Most predictions are based on the physical conditions prevailing at or before the <span class="hlt">solar</span> cycle minimum preceding the maximum in question. Our aim is to predict the maximum peak of cycle 24 using precursor techniques in particular those using spotless event, geomagnetic aa min. index and <span class="hlt">solar</span> flux F10.7. Also prediction of exact date of the maximum (Tr) is taken in consideration. A study of variation over previous spotless event for cycles 7-23 and that for even cycles (8-22) are carried out for the prediction. Linear correlation between RM and spotless event around the preceding minimum gives RM24t = 101.9with rise time Tr = 4.5 Y. For the even cycles RM24e = 108.3 with rise time Tr = 3.9 Y. Based on the average aa min. index for the year of sunspot minimum cycles (13 - 23), we estimate the expected amplitude for cycle 24 to be RMaa = 116.5 for both the total and even cycles. Application of the data of <span class="hlt">solar</span> flux F10.7 which cover only cycles (19-23) was taken in consideration and gives predicted maximum amplitude R24 10.7 = 146, which are over estimation. Our result indicating a somewhat weaker cycle 24 as compared to cycles 21-23.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21460128','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21460128"><span id="translatedtitle"><span class="hlt">SOLAR</span> ROTATION RATE DURING THE CYCLE 24 MINIMUM IN <span class="hlt">ACTIVITY</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Antia, H. M.; Basu, Sarbani E-mail: sarbani.basu@yale.ed</p> <p>2010-09-01</p> <p>The minimum of <span class="hlt">solar</span> cycle 24 is significantly different from most other minima in terms of its duration as well as its abnormally low levels of <span class="hlt">activity</span>. Using available helioseismic data that cover epochs from the minimum of cycle 23 to now, we study the differences in the nature of the <span class="hlt">solar</span> rotation between the minima of cycles 23 and 24. We find that there are significant differences between the rotation rates during the two minima. There are differences in the zonal-flow pattern too. We find that the band of fast rotating region close to the equator bifurcated around 2005 and recombined by 2008. This behavior is different from that during the cycle 23 minimum. By autocorrelating the zonal-flow pattern with a time shift, we find that in terms of <span class="hlt">solar</span> dynamics, <span class="hlt">solar</span> cycle 23 lasted for a period of 11.7 years, consistent with the result of Howe et al. (2009). The autocorrelation coefficient also confirms that the zonal-flow pattern penetrates through the convection zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRA..117.4207T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRA..117.4207T"><span id="translatedtitle">Dependence of the amplitude of Pc5-band magnetic field variations on the <span class="hlt">solar</span> wind and <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takahashi, Kazue; Yumoto, Kiyohumi; Claudepierre, Seth G.; Sanchez, Ennio R.; Troshichev, Oleg A.; Janzhura, Alexander S.</p> <p>2012-04-01</p> <p>We have studied the dependence of the amplitude of magnetic field variations in the Pc5 band (1.6-6.7 mHz) on the <span class="hlt">solar</span> wind and <span class="hlt">solar</span> <span class="hlt">activity</span>. <span class="hlt">Solar</span> wind parameters considered are the bulk velocity Vsw and the variation of the <span class="hlt">solar</span> wind dynamic pressure δPsw. The <span class="hlt">solar</span> <span class="hlt">activity</span> dependence is examined by contrasting observations made in 2001 (<span class="hlt">solar</span> <span class="hlt">activity</span> maximum) and 2006 (<span class="hlt">solar</span> <span class="hlt">activity</span> declining phase). We calculated hourly Pc5 amplitude using data from geostationary satellites at L = 6.8 and ground stations covering 1 < L < 9. The amplitude is positively correlated with both Vsw and δPsw, but the degree of correlation varies with L and magnetic local time. As measured by the correlation coefficient, the amplitude dependence on both Vsw and δPsw is stronger on the dayside than on the nightside, and the dependence on Vsw (δPsw) tends to be stronger at higher (lower) L, with the relative importance of the two <span class="hlt">solar</span> wind parameters switching at L ˜ 5. We attribute the Vsw control to the Kelvin-Helmholtz instability on the magnetopause, occurring both at high and low latitudes, and the δPsw control to buffeting of the magnetosphere by variation of <span class="hlt">solar</span> wind dynamic pressure. The GOES amplitude is higher at the <span class="hlt">solar</span> maximum at all local times and the same feature is seen on the ground in the dawn sector at L > 6. A radial shift of the fast mode wave turning point, associated with the <span class="hlt">solar</span> cycle variation of magnetosphere mass density, is a possible cause of this <span class="hlt">solar</span> <span class="hlt">activity</span> dependence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920024232','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920024232"><span id="translatedtitle"><span class="hlt">Influence</span> of mass moment of inertia on normal modes of preloaded <span class="hlt">solar</span> array mast</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Armand, Sasan C.; Lin, Paul</p> <p>1992-01-01</p> <p>Earth-orbiting spacecraft often contain <span class="hlt">solar</span> arrays or antennas supported by a preloaded mast. Because of weight and cost considerations, the structures supporting the spacecraft appendages are extremely light and flexible; therefore, it is vital to investigate the <span class="hlt">influence</span> of all physical and structural parameters that may <span class="hlt">influence</span> the dynamic behavior of the overall structure. The study primarily focuses on the mast for the space station <span class="hlt">solar</span> arrays, but the formulations and the techniques developed in this study apply to any large and flexible mast in zero gravity. Furthermore, to determine the <span class="hlt">influence</span> on the circular frequencies, the mass moment of inertia of the mast was incorporated into the governing equation of motion for bending. A finite element technique (MSC/NASTRAN) was used to verify the formulation. Results indicate that when the mast is relatively flexible and long, the mass moment inertia <span class="hlt">influences</span> the circular frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23916132','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23916132"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">activity</span> on plantar force distribution.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reinschmidt, C; Nigg, B M; Hamilton, G R</p> <p>1994-03-01</p> <p>The purpose of the study was to quantify the <span class="hlt">influence</span> of physical <span class="hlt">activity</span> on force distribution on the plantar surface of the foot. Eleven healthy subjects each performed 10 walking trials over a force distribution platform: five trials before and five trials after a 30-min run. For the analysis the foot was divided into three different regions (rearfoot, midfoot, forefoot), and maximal and average forces were determined for each region. The only statistically significant difference was found in the maximal force in the forefoot, but the difference was relatively small (<3%). The results suggested that the half-hour run did not have a large effect on the plantar force distribution. Differences between subjects were significant for all variables, indicating that relevant information on individual foot structure and/or gait may be obtained from the plantar force distribution. PMID:23916132</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1817390F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1817390F&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Active</span> other worlds in the <span class="hlt">Solar</span> System and beyond</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Forget, François</p> <p>2016-04-01</p> <p>Over the past decades, space exploration has moved planetology from the field of astronomy to the disciplines of geosciences. A fleet of spacecrafts have discovered and study tens of worlds in our <span class="hlt">solar</span> system and beyond. Everywhere, we have been surprised by the diversity and the vigour of the geophysical <span class="hlt">activity</span>, from volcanic eruptions to plasma waves... Every scientists present at EGU could -and should- be interested in the extraterrestrial processes that are discovered and analyzed elsewhere. In our <span class="hlt">solar</span> system, a variety of clouds and fluid dynamical phenomena can be studied in six terrestrial atmospheres and on four giant planets. <span class="hlt">Active</span> glaciers are found on Mars and Pluto. Rivers and lakes have sculpted the surface of Titan and Mars. Sometime, we can even study geophysical <span class="hlt">activity</span> with no equivalent on our planet: ice caps made of frozen atmosphere that erupt in geysers, hazes formed by organic polymers which can completely shroud a moon, etc. We study these <span class="hlt">active</span> worlds because we are curious and wish to understand our universe and our origins. However, more than ever, two specific motivations drive <span class="hlt">solar</span> system geosciences in 2016: Firstly, as we become more and more familiar with the other worlds around us, we can use them to better understand our own planet. Throughout the <span class="hlt">solar</span> system, we can access to data that are simply not available on the Earth, or study <span class="hlt">active</span> processes that are subtle on Earth but of greater importance elsewhere, so that we can better understand them. Many geophysical concepts and tools developed for the Earth can also be tested on other planets. For instance the numerical Climate Models used to assess Earth's future climate change are applied to other planets. Much is learned from such experiments. Secondly, the time has come to generalize the fundamental lessons that we have learned from the examples in the <span class="hlt">solar</span> system (including the Earth) to address the countless scientific questions that are -and will be- raised by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.435.2109L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.435.2109L"><span id="translatedtitle">Planetary <span class="hlt">influence</span> on the young Sun's evolution: the <span class="hlt">solar</span> neutrino probe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopes, Ilídio; Silk, Joseph</p> <p>2013-11-01</p> <p>Recent observations of <span class="hlt">solar</span> twin stars with planetary systems, like the Sun, have uncovered that these present a peculiar surface chemical composition. This is believed to be related to the formation of earth-like planets. This suggests that twin stars have a radiative interior that is richer in heavy elements than their envelopes. Moreover, the current standard <span class="hlt">solar</span> model does not fully agree with the helioseismology data and <span class="hlt">solar</span> neutrino flux measurements. In this work, we find that this agreement can improve if the Sun has mass-loss during the pre-main sequence, as was previously shown by other groups. Despite this better agreement, the internal composition of the Sun is still uncertain, especially for elements heavier than helium. With the goal of inferring the chemical abundance of the <span class="hlt">solar</span> interior, we tested several chemical compositions. We found that heavy element abundances <span class="hlt">influence</span> the sound speed and <span class="hlt">solar</span> neutrinos equally. Nevertheless, the carbon-nitrogen-oxygen (CNO; 13N, 15O and 17F) neutrino fluxes are the most affected; this is due to the fact that contrarily to proton-proton (pp, pep, 8B and 7Be) neutrino fluxes, the CNO neutrino fluxes are less dependent on the total luminosity of the star. Furthermore, if the central <span class="hlt">solar</span> metallicity increases by 30 per cent, as hinted by the <span class="hlt">solar</span> twin stars observations, this new <span class="hlt">solar</span> model predicts that 13N, 15O and 17F neutrino fluxes increase by 25-80 per cent relative to the standard <span class="hlt">solar</span> model. Finally, we highlight that the next generation of <span class="hlt">solar</span> neutrino experiments will not only put constraints on the abundances of carbon, oxygen and nitrogen, but will also give some information about their radial distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.1209S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.1209S"><span id="translatedtitle">Corroboration for the <span class="hlt">influence</span> of a component of <span class="hlt">solar</span> irradiance on subsurface radon signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steinitz, G.; Piatibratova, O.; Kotlarsky, P.; Sturrock, P.; Maritn, C.</p> <p>2012-04-01</p> <p>Rn-222 occurs at highly varying levels as a trace component in subsurface air (geogas). This high variability is traced by alpha and gamma <span class="hlt">activity</span> due to the decay of radon and its progeny. Nuclear radiation from radon in geogas and in experiments using air+radon within a confined volume exhibits systematic temporal variations. These variations are composed of periodic and non-periodic signals spanning several orders of magnitude in time - from annual to daily and sub-daily durations. Analysis of extensive data sets from three key sites 200 km apart in the arid desert of southern Israel [1-3] and from a 5-year experiment using alpha and gamma detectors [4] demonstrate that the periodic variations, observed to a depth of >100 meters, are related to an above surface driver probably due to a component of <span class="hlt">solar</span> irradiance. Insight was also derived from the long term variations in the geological and the experimental time series [5], indicated by the occurrence of multi-year variations, and clear semiannual and ternary annual signals which are in addition to the annual periodicity. New confirmations are based on recognizing further cyclic phenomena, some of which are not linked with Earth related periodicities. A likehood analysis of the alpha and gamma time series in a long-term experiment is performed. A Combined Power Statistic formed from the gamma, alpha-H and alpha-L sensors inside the experimental tank shows that the time series of the gamma radiation contains an annual periodicity as well as a clear semi-annual and possibly a ternary-annual periodicity. The same analysis also resolves additional periodicities in the frequency range of 10-15 yr-1 in the gamma time series which are indicative of a relationship to rotation of the sun around its axis [6]. Observation of <span class="hlt">solar</span> periodicities in the temporal pattern of the nuclear radiation of radon is a significant independent substantiation for the notion of the <span class="hlt">influence</span> of a component in <span class="hlt">solar</span> irradiance. An</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.158A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.158A"><span id="translatedtitle">The role of EUV/X-ray <span class="hlt">solar</span> <span class="hlt">activity</span> and electron precipitations from radiation belts in the climate changes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avakyan, Sergey; Voronin, Nikolai; Baranova, Lubov</p> <p></p> <p>The authors associate the recently observed climate warming and carbon dioxide concentration growth in lower atmospheric layers with variations of the <span class="hlt">solar</span>-geomagnetic <span class="hlt">activity</span> contribution to global cloud formation and with significant decrease of carbon dioxide accumulation in forests in the process of photosynthesis. The contribution of the greenhouse effect of carbon-bearing gases to global warming turns out to be insignificant. We consider the impact of microwave emissions of the ionosphere disturbed by <span class="hlt">solar</span> flares and magnetic storms on the troposphere and suggest the radio-optical trigger mechanism of the <span class="hlt">solar</span> <span class="hlt">influence</span> on weather and climate of the Earth, which consists of the following three stages: - the ionosphere absorbs the ionizing <span class="hlt">solar</span> radiation and corpuscles from the radiation belts and transforms these into microwaves through the excitation of Rydberg states by electron impact (ionospheric photoelectron, secondary and Auger electrons); - the rates of formation and destruction of water cluster ions in the troposphere are regulated by the microwave radiation; - the clusters contribute to formation of clouds, which affects the energy flux of <span class="hlt">solar</span> radiation through the troposphere and the flux of outgoing heat from the underlying surface. All stages of the proposed mechanism were strictly confirmed: amplification of ionospheric microwave radiation during <span class="hlt">solar</span> flares and magnetic storms was detected; the regulation of humidity at altitude above 2 km by <span class="hlt">solar</span> microwave emission during <span class="hlt">solar</span> flares was registered; an <span class="hlt">influence</span> of <span class="hlt">solar</span> flares and magnetic storms on the cloudiness is distinctly registered at least in some geographic areas; a direct <span class="hlt">influence</span> of <span class="hlt">solar</span>-geomagnetic <span class="hlt">activity</span> on the global total cloud cover in latest maximum of secular variability (in 1985 - in electromagnetic <span class="hlt">solar</span> <span class="hlt">activity</span>, and in 2003 - in geomagnetic <span class="hlt">activity</span>) was discovered. Basing on analysis of satellite data on global cloud cover and radiation balance the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22370310','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22370310"><span id="translatedtitle">Prediction of <span class="hlt">solar</span> <span class="hlt">activity</span> from <span class="hlt">solar</span> background magnetic field variations in cycles 21-23</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shepherd, Simon J.; Zharkov, Sergei I.; Zharkova, Valentina V. E-mail: s.zharkov@hull.ac.uk</p> <p>2014-11-01</p> <p>A comprehensive spectral analysis of both the <span class="hlt">solar</span> background magnetic field (SBMF) in cycles 21-23 and the sunspot magnetic field in cycle 23 reported in our recent paper showed the presence of two principal components (PCs) of SBMF having opposite polarity, e.g., originating in the northern and southern hemispheres, respectively. Over a duration of one <span class="hlt">solar</span> cycle, both waves are found to travel with an increasing phase shift toward the northern hemisphere in odd cycles 21 and 23 and to the southern hemisphere in even cycle 22. These waves were linked to <span class="hlt">solar</span> dynamo waves assumed to form in different layers of the <span class="hlt">solar</span> interior. In this paper, for the first time, the PCs of SBMF in cycles 21-23 are analyzed with the symbolic regression technique using Hamiltonian principles, allowing us to uncover the underlying mathematical laws governing these complex waves in the SBMF presented by PCs and to extrapolate these PCs to cycles 24-26. The PCs predicted for cycle 24 very closely fit (with an accuracy better than 98%) the PCs derived from the SBMF observations in this cycle. This approach also predicts a strong reduction of the SBMF in cycles 25 and 26 and, thus, a reduction of the resulting <span class="hlt">solar</span> <span class="hlt">activity</span>. This decrease is accompanied by an increasing phase shift between the two predicted PCs (magnetic waves) in cycle 25 leading to their full separation into the opposite hemispheres in cycle 26. The variations of the modulus summary of the two PCs in SBMF reveals a remarkable resemblance to the average number of sunspots in cycles 21-24 and to predictions of reduced sunspot numbers compared to cycle 24: 80% in cycle 25 and 40% in cycle 26.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002cosp...34E2656L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002cosp...34E2656L&link_type=ABSTRACT"><span id="translatedtitle">On the <span class="hlt">Influence</span> of the <span class="hlt">Solar</span> Bi-Cycle on Comic Ray Modulatio</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lifter, N. Part Xxvii: A. Defect Of The Solar Dynamo. B.; Scissors, K.; Sprucener, H.</p> <p></p> <p>In this presentation we propose a new paradigm that explains the different lengths of individual <span class="hlt">solar</span> Hale cycles. It proves beneficial to distinguish between a so-called inHale and ex-Hale cycle, which together form the <span class="hlt">solar</span> bi-cycle. We carefully analyzed the <span class="hlt">influence</span> of so-called complex mode excitations (CMEs) on comic ray modulation, in particular on the drifts of the comic isotope O+3 , which we found to induce characteristic anisotropies. This comic isotope anisotropy (CIA) is caused by the wellknown north-south asymmetry (NSA) and can be observed as a rare Forbush increase (FBI). The latter is linked to the <span class="hlt">solar</span> magnetic field which appears to have a chaotic behaviour (for details see part I-XXVI). Especially during an ex-Hale cycle magnetic flux is pseudo-pneumatically escaping through a coronal hole. Consequently, the <span class="hlt">solar</span> dynamo can no longer operate efficiently, i.e. is defect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6745Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6745Y"><span id="translatedtitle">A new simple dynamo model for <span class="hlt">solar</span> <span class="hlt">activity</span> cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yokoi, Nobumitsu; Schmitt, Dieter</p> <p>2015-04-01</p> <p>The <span class="hlt">solar</span> magnetic <span class="hlt">activity</span> cycle has been investigated in an elaborated manner with several types of dynamo models [1]. In most of the current mean-field approaches, the inhomogeneity of the large-scale flow is treated as an essential ingredient in the mean magnetic field equation whereas it is completely neglected in the turbulence equation. In this work, a new simple model for the <span class="hlt">solar</span> <span class="hlt">activity</span> cycle is proposed. The present model differs from the previous ones mainly in two points. First, in addition to the helicity coefficient α, we consider a term related to the cross helicity, which represents the effect of the inhomogeneous mean flow, in the turbulent electromotive force [2, 3]. Second, this transport coefficient (γ) is not treated as an adjustable parameter, but the evolution equation for γ is simultaneously solved. The basic scenario for the <span class="hlt">solar</span> <span class="hlt">activity</span> cycle in this approach is as follows: The toroidal field is induced by the toroidal rotation in mediation by the turbulent cross helicity. Then due to the α or helicity effect, the poloidal field is generated from the toroidal field. The poloidal field induced by the α effect produces a turbulent cross helicity whose sign is opposite to the original one (negative cross-helicity production). The cross helicity with this opposite sign induces a reversed toroidal field. Results of the eigenvalue analysis of the model equations are shown, which confirm the above scenario. References [1] Charbonneau, Living Rev. <span class="hlt">Solar</span> Phys. 7, 3 (2010). [2] Yoshizawa, A. Phys. Fluids B 2, 1589 (1990). [3] Yokoi, N. Geophys. Astrophys. Fluid Dyn. 107, 114 (2013).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010ERL.....5b1001B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010ERL.....5b1001B&link_type=ABSTRACT"><span id="translatedtitle">PERSPECTIVE: Low <span class="hlt">solar</span> <span class="hlt">activity</span> is blamed for winter chill over Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benestad, Rasmus E.</p> <p>2010-06-01</p> <p> the direct effect from changes in the <span class="hlt">solar</span> brightness (0.1%) was estimated to be too low to explain the temperature changes on Earth. The <span class="hlt">solar</span> <span class="hlt">influence</span> on changes in the global mean temperature has so far been found to be weak (Lean 2010, Benestad and Schmidt 2009). The important difference between recent and early studies is, however, that the latter lacked a theoretical framework based on physical mechanisms. Now we understand that stratospheric conditions vary, and are affected by chemical reactions as well as the absorption of UV light. Furthermore, we know that such variations affect temperature profiles, wave propagations, and winds (Schindell et al 2001). Lean (2010) and Haigh (2003) provide nice reviews of recent progress on <span class="hlt">solar</span>-terrestrial relationships, although questions regarding the quality of the oldest <span class="hlt">solar</span> data records are still unanswered (Benestad 2005). All these studies still rely on empirical data analysis. Much of the focus of the recent work has been on climate variation on global scales. The recent paper by Lockwood et al (2010) represents current progress, albeit that they emphasize that the relationship they identify has a regional rather than global character. Indeed, they stress that a change in the global mean temperature should not be confused with regional and seasonal means. The physical picture they provide is plausible, yet empirical relationships between <span class="hlt">solar</span> <span class="hlt">activity</span> and any of the indices describing the north Atlantic oscillation, the Arctic oscillation or the polar vortex are regarded as weak. My impression is nevertheless that the explanation provided by the Lockwood et al (2010) study reflects real aspects of our climate, especially if the effect is asymmetric. They argue that <span class="hlt">solar</span>-induced changes in the stratosphere in turn affect the occurrence of persistent wintertime blocking. But one comprehensive, definite, consistent, and convincing documentation of the entire chain causality is still not in place, due to the lack</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7459B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7459B"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> and climate change during the 1750 A.D. <span class="hlt">solar</span> minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bard, Edouard; Baroni, Mélanie; Aster Team</p> <p>2015-04-01</p> <p>The number of sunspots and other characteristics have been widely used to reconstruct the <span class="hlt">solar</span> <span class="hlt">activity</span> beyond the last three decades of accurate satellite measurements. It has also been possible to reconstruct the long-term <span class="hlt">solar</span> behavior by measuring the abundance on Earth of cosmogenic nuclides such as carbon 14 and beryllium 10. These isotopes are formed by the interaction of galactic cosmic rays with atmospheric molecules. Accelerator mass spectrometry is used to measure the abundance of these isotopes in natural archives such as polar ice (for 10Be), tree rings and corals (for 14C). Over the last millennium, the <span class="hlt">solar</span> <span class="hlt">activity</span> has been dominated by alternating <span class="hlt">active</span> and quiet periods, such as the Maunder Minimum, which occurred between 1645 and 1715 A.D. The climate forcing of this <span class="hlt">solar</span> variability is the subject of intense research, both because the exact scaling in terms of irradiance is still a matter of debate and because other <span class="hlt">solar</span> variations may have played a role in amplifying the climatic response. Indeed, the past few decades of accurate <span class="hlt">solar</span> measurements do not include conditions equivalent to an extended <span class="hlt">solar</span> minimum. A further difficulty of the analysis lies in the presence of other climate forcings during the last millennium, which are superimposed on the <span class="hlt">solar</span> variations. Finally, the inherent precision of paleotemperature proxies are close to the signal amplitude retrieved from various paleoclimate archives covering the last millennium. Recent model-data comparisons for the last millennium have led to the conclusion that the <span class="hlt">solar</span> forcing during this period was minor in comparison to volcanic eruptions and greenhouse gas concentrations (e.g. Schurer et al. 2013 J. Clim., 2014 Nat. Geo.). In order to separate the different forcings, it is useful to focus on a temperature change in phase with a well-documented <span class="hlt">solar</span> minimum so as to maximize the response to this astronomical forcing. This is the approach followed by Wagner et al. (2005 Clim</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910009603','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910009603"><span id="translatedtitle">Simultaneous <span class="hlt">Solar</span> Maximum Mission (SMM) and Very Large Array (VLA) observations of <span class="hlt">solar</span> <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Willson, Robert F.</p> <p>1991-01-01</p> <p>Very Large Array observations at 20 cm wavelength can detect the hot coronal plasma previously observed at soft x ray wavelengths. Thermal cyclotron line emission was detected at the apex of coronal loops where the magnetic field strength is relatively constant. Detailed comparison of simultaneous <span class="hlt">Solar</span> Maximum Mission (SMM) Satellite and VLA data indicate that physical parameters such as electron temperature, electron density, and magnetic field strength can be obtained, but that some coronal loops remain invisible in either spectral domain. The unprecedent spatial resolution of the VLA at 20 cm wavelength showed that the precursor, impulsive, and post-flare components of <span class="hlt">solar</span> bursts originate in nearby, but separate loops or systems of loops.. In some cases preburst heating and magnetic changes are observed from loops tens of minutes prior to the impulsive phase. Comparisons with soft x ray images and spectra and with hard x ray data specify the magnetic field strength and emission mechanism of flaring coronal loops. At the longer 91 cm wavelength, the VLA detected extensive emission interpreted as a hot 10(exp 5) K interface between cool, dense H alpha filaments and the surrounding hotter, rarefield corona. Observations at 91 cm also provide evidence for time-correlated bursts in <span class="hlt">active</span> regions on opposite sides of the <span class="hlt">solar</span> equator; they are attributed to flare triggering by relativistic particles that move along large-scale, otherwise-invisible, magnetic conduits that link <span class="hlt">active</span> regions in opposite hemispheres of the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E3663X&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E3663X&link_type=ABSTRACT"><span id="translatedtitle">A statistic study of ionospheric <span class="hlt">solar</span> flare <span class="hlt">activity</span> indicator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Bo; Ding, Feng; Ning, Baiqi; Wan, Weixing; Yu, You; Hu, Lianhuan</p> <p></p> <p>According to the Chapman ionization theory, an ionospheric <span class="hlt">solar</span> flare <span class="hlt">activity</span> indicator (ISFAI) is given by the <span class="hlt">solar</span> zenith angle and the variation rate of ionospheric vertical total electron content, which is measured from a global network of dual-frequency GPS receivers. The ISFAI is utilized to statistically analyze the ionospheric responses to 1439 M-class and 126 X-class <span class="hlt">solar</span> flares during <span class="hlt">solar</span> cycle 23 (1996-2008). The statistical results show that the occurrence of ISFAI peak increases obviously at 3.2 total electron content unit (TECU)/h (1 TECU = 1016 elm-2) and reaches the maximum at 10 TECU/h during M-class flares and 10 TECU/h and 40 TECU/h for X-class flares. ISFAI is closely correlated with the 26-34 nm extreme ultraviolet flux but poorly related to the 0.1-0.8 nm X-ray flux. The central meridian distance (CMD) of flare location is an important reason for depressing relationship between ISFAI and X-ray Flux. Through the CMD effect modification, the ISFAI has a significant dependence on the X-ray flux with a correlation coefficient of 0.76. The ISFAI sensitivity enables to detect the extreme X-class flares, as well as the variations of one order of magnitude or even smaller (such as for C-class flares). Meanwhile, ISFAI is helpful to the calibration of the X-ray flux at 0.1-0.8 nm observed by GOES during some flares. In addition, statistical results demonstrate that ISFAI can detect 80% of all M-class flares and 92% for all X-class ones during 1996-2008. Owing to the high sensitivity and temporal resolution, ISFAI can be utilized as a <span class="hlt">solar</span> flare detection parameter to monitor space weather.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940006941','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940006941"><span id="translatedtitle">NASDA <span class="hlt">activities</span> in space <span class="hlt">solar</span> power system research, development and applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matsuda, Sumio; Yamamoto, Yasunari; Uesugi, Masato</p> <p>1993-01-01</p> <p>NASDA <span class="hlt">activities</span> in <span class="hlt">solar</span> cell research, development, and applications are described. First, current technologies for space <span class="hlt">solar</span> cells such as Si, GaAs, and InP are reviewed. Second, future space <span class="hlt">solar</span> cell technologies intended to be used on satellites of 21st century are discussed. Next, the flight data of <span class="hlt">solar</span> cell monitor on ETS-V is shown. Finally, establishing the universal space <span class="hlt">solar</span> cell calibration system is proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27485403','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27485403"><span id="translatedtitle">Alternating Current <span class="hlt">Influences</span> Anaerobic Electroactive Biofilm <span class="hlt">Activity</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xin; Zhou, Lean; Lu, Lu; Lobo, Fernanda Leite; Li, Nan; Wang, Heming; Park, Jaedo; Ren, Zhiyong Jason</p> <p>2016-09-01</p> <p>Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC <span class="hlt">influences</span> anaerobic biofilm <span class="hlt">activities</span> has not been systematically investigated. Using a Geobacter dominated anaerobic biofilm growing on the electrodes of microbial electrochemical reactors, we found that high frequency AC ranging from 1 MHz to 1 kHz (amplitude of 5 V, 30 min) showed only temporary inhibition to the biofilm <span class="hlt">activity</span>. However, lower frequency (100 Hz, 1.2 or 5 V) treatment led to 47 ± 19% permanent decrease in limiting current on the same biofilm, which is attributed to the action of electrohydrodynamic force that caused biofilm damage and loss of intercellular electron transfer network. Confocal microscopy images show such inactivation mainly occurred at the interface between the biofilm and the electrode. Reducing the frequency further to 1 Hz led to water electrolysis, which generated gas bubbles that flushed all attached cells out of the electrode. These findings provide new references on understanding and regulating biofilm growth, which has broader implications in biofouling control, anaerobic waste treatment, energy and product recovery, and general understanding of microbial ecology and physiology. PMID:27485403</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459182','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459182"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span> variability on the infrared radiative cooling of the thermosphere from 2002 to 2014</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mlynczak, Martin G; Hunt, Linda A; Mertens, Christopher J; Thomas Marshall, B; Russell, James M; Woods, Thomas; Earl Thompson, R; Gordley, Larry L</p> <p>2014-01-01</p> <p>Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete <span class="hlt">solar</span> cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year <span class="hlt">solar</span> cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008–2009. Current <span class="hlt">solar</span> maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002–2003. The observed changes in thermospheric cooling correlate well with changes in <span class="hlt">solar</span> ultraviolet irradiance and geomagnetic <span class="hlt">activity</span> during the prior maximum conditions. NO and CO2 combine to emit 7 × 1018 more Joules annually at <span class="hlt">solar</span> maximum than at <span class="hlt">solar</span> minimum. Key Points First record of thermospheric IR cooling rates over a complete <span class="hlt">solar</span> cycleIR cooling in current <span class="hlt">solar</span> maximum conditions much weaker than prior maximumVariability in thermospheric IR cooling observed on scale of days to 11 years PMID:26074647</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22363994','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22363994"><span id="translatedtitle">DISTRIBUTION OF ELECTRIC CURRENTS IN <span class="hlt">SOLAR</span> <span class="hlt">ACTIVE</span> REGIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Török, T.; Titov, V. S.; Mikić, Z.; Leake, J. E.; Archontis, V.; Linton, M. G.; Dalmasse, K.; Aulanier, G.; Kliem, B.</p> <p>2014-02-10</p> <p>There has been a long-standing debate on the question of whether or not electric currents in <span class="hlt">solar</span> <span class="hlt">active</span> regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the <span class="hlt">active</span> region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar <span class="hlt">active</span> region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the <span class="hlt">solar</span> atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the <span class="hlt">active</span> region's polarity inversion line. After the region has formed and flux emergence has ceased, the strong magnetic fields in the region's center are connected solely by direct currents, and the total direct current is several times larger than the total return current. These results suggest that <span class="hlt">active</span> regions, the main sources of coronal mass ejections and flares, are born with substantial net currents, in agreement with recent observations. Furthermore, they support eruption models that employ pre-eruption magnetic fields containing such currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1677e0003H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1677e0003H"><span id="translatedtitle">On the possible relations between <span class="hlt">solar</span> <span class="hlt">activities</span> and global seismicity in the <span class="hlt">solar</span> cycle 20 to 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi</p> <p>2015-09-01</p> <p><span class="hlt">Solar</span> <span class="hlt">activities</span> consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know <span class="hlt">solar</span> <span class="hlt">activity</span> main indicator is the existence of sunspot which has mean variation in 11 years, named by <span class="hlt">solar</span> cycle, allow for the above fluctuations. <span class="hlt">Solar</span> <span class="hlt">activities</span> are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth's climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the <span class="hlt">activities</span> of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between <span class="hlt">solar</span> forcing energy to the Earth's global seismic <span class="hlt">activities</span>. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic <span class="hlt">activities</span> that refer to and sunspot number within the <span class="hlt">solar</span> cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22488913','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22488913"><span id="translatedtitle">On the possible relations between <span class="hlt">solar</span> <span class="hlt">activities</span> and global seismicity in the <span class="hlt">solar</span> cycle 20 to 23</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi</p> <p>2015-09-30</p> <p><span class="hlt">Solar</span> <span class="hlt">activities</span> consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know <span class="hlt">solar</span> <span class="hlt">activity</span> main indicator is the existence of sunspot which has mean variation in 11 years, named by <span class="hlt">solar</span> cycle, allow for the above fluctuations. <span class="hlt">Solar</span> <span class="hlt">activities</span> are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth’s climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the <span class="hlt">activities</span> of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between <span class="hlt">solar</span> forcing energy to the Earth’s global seismic <span class="hlt">activities</span>. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic <span class="hlt">activities</span> that refer to and sunspot number within the <span class="hlt">solar</span> cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1414N&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1414N&link_type=ABSTRACT"><span id="translatedtitle">Non-Stationary Effects and Cross Correlations in <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nefedyev, Yuri; Panischev, Oleg; Demin, Sergey</p> <p>2016-07-01</p> <p>In this paper within the framework of the Flicker-Noise Spectroscopy (FNS) we consider the dynamic properties of the <span class="hlt">solar</span> <span class="hlt">activity</span> by analyzing the Zurich sunspot numbers. As is well-known astrophysics objects are the non-stationary open systems, whose evolution are the quite individual and have the alternation effects. The main difference of FNS compared to other related methods is the separation of the original signal reflecting the dynamics of <span class="hlt">solar</span> <span class="hlt">activity</span> into three frequency bands: system-specific "resonances" and their interferential contributions at lower frequencies, chaotic "random walk" ("irregularity-jump") components at larger frequencies, and chaotic "irregularity-spike" (inertial) components in the highest frequency range. Specific parameters corresponding to each of the bands are introduced and calculated. These irregularities as well as specific resonance frequencies are considered as the information carriers on every hierarchical level of the evolution of a complex natural system with intermittent behavior, consecutive alternation of rapid chaotic changes in the values of dynamic variables on small time intervals with small variations of the values on longer time intervals ("laminar" phases). The jump and spike irregularities are described by power spectra and difference moments (transient structural functions) of the second order. FNS allows revealing the most crucial points of the <span class="hlt">solar</span> <span class="hlt">activity</span> dynamics by means of "spikiness" factor. It is shown that this variable behaves as the predictor of crucial changes of the sunspot number dynamics, particularly when the number comes up to maximum value. The change of averaging interval allows revealing the non-stationary effects depending by 11-year cycle and by inside processes in a cycle. To consider the cross correlations between the different variables of <span class="hlt">solar</span> <span class="hlt">activity</span> we use the Zurich sunspot numbers and the sequence of corona's radiation energy. The FNS-approach allows extracting the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20090001864&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dactivity%2BPhysics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20090001864&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dactivity%2BPhysics"><span id="translatedtitle">Triennial Report 2006-2009. Commission 10: <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klimchuk, James A.</p> <p>2008-01-01</p> <p>Commission 10 deals with <span class="hlt">solar</span> <span class="hlt">activity</span> in all of its forms, ranging from the smallest nanoflares to the largest coronal mass ejections. This report reviews scientific progress over the roughly two-year period ending in the middle of 2008. This has been an exciting time in <span class="hlt">solar</span> physics, highlighted by the launches of the Hinode and STEREO missions late in 2006. The report is reasonably comprehensive, though it is far from exhaustive. Limited space prevents the inclusion of many significant results. The report is divided into following sections: Photosphere and Chromosphere; Transition Region; Corona and Coronal Heating; Coronal Jets; Flares; Coronal Mass Ejection Initiation; Global Coronal Waves and Shocks; Coronal Dimming; The Link Between Low Coronal CME signatures and Magnetic Clouds; Coronal Mass Ejections in the Heliosphere; and Coronal Mass Ejections and Space Weather. Primary authorship is indicated at the beginning of each section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080038051&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dactivity%2BPhysics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080038051&hterms=activity+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dactivity%2BPhysics"><span id="translatedtitle">The Role of Magnetic Reconnection in <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Antiochos, Spiro; DeVore, C. R.</p> <p>2008-01-01</p> <p>The central challenge in <span class="hlt">solar</span>/heliospheric physics is to understand how the emergence and transport of magnetic flux at the photosphere drives the structure and dynamics that we observe in the corona and heliosphere. This presentation focuses on the role of magnetic reconnection in determining <span class="hlt">solar</span>/heliospheric <span class="hlt">activity</span>. We demonstrate that two generic properties of the photospheric magnetic and velocity fields are responsible for the ubiquitous reconnection in the corona. First, the photospheric velocities are complex, which leads to the injection of energy and helicity into the coronal magnetic fields and to the efficient, formation of small-scale structure. Second, the flux distribution at the photosphere is multi-polar, which implies that topological discontinuities and, consequently, current sheets, must be present in the coronal magnetic field. We: present numerical simulations showing that photospherically-driven reconnection is responsible for the heating and dynamics of coronal plasma, and for the topology of the coronal/heliospheric magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010094559&hterms=NOAA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DNOAA','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010094559&hterms=NOAA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DNOAA"><span id="translatedtitle">Multi-wavelength Observations of <span class="hlt">Solar</span> <span class="hlt">Active</span> Region NOAA 7154</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bruner, M. E.; Nitta, N. V.; Frank. Z. A.; Dame, L.; Suematsu, Y.</p> <p>2000-01-01</p> <p>We report on observations of a <span class="hlt">solar</span> <span class="hlt">active</span> region in May 1992 by the <span class="hlt">Solar</span> Plasma Diagnostic Experiment (SPDE) in coordination with the Yohkoh satellite (producing soft X-ray images) and ground-based observatories (producing photospheric magnetograms and various filtergrams including those at the CN 3883 A line). The main focus is a study of the physical conditions of hot (T is approximately greater than 3 MK) coronal loops at their foot-points. The coronal part of the loops is fuzzy but what appear to be their footpoints in the transition region down to the photosphere are compact. Despite the morphological similarities, the footpoint emission at 10(exp 5) K is not quantitatively correlated with that at approximately 300 km above the tau (sub 5000) = 1 level, suggesting that the heat transport and therefore magnetic field topology in the intermediate layer is complicated. High resolution imaging observations with continuous temperature coverage are crucially needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAVSO..44Q..83D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAVSO..44Q..83D"><span id="translatedtitle">Impacts of Extended Periods of Low <span class="hlt">Solar</span> <span class="hlt">Activity</span> on Climate (Abstract)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denig, W. F.</p> <p>2016-06-01</p> <p>(Abstract only) There has been great interest in determining the length and amplitude of <span class="hlt">Solar</span> Cycle 24 in recent years, in part due to increasing speculation that the current <span class="hlt">solar</span> minimum is anomalously quiet and perhaps signaling the beginning of a decreased period of <span class="hlt">solar</span> <span class="hlt">activity</span> in the coming decades. We aim to examine the current <span class="hlt">solar</span> minimum and compare it to previous <span class="hlt">solar</span> minima in order to: determine if the current minimum shares characteristics with other historically quiet <span class="hlt">solar</span> minima (sometimes referred to as grand minima); outline the potential consequences of a grand minimum with respect to climate; and predict the future of <span class="hlt">Solar</span> Cycle 24.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sensor+AND+temperature&pg=3&id=EJ310571','ERIC'); return false;" href="http://eric.ed.gov/?q=sensor+AND+temperature&pg=3&id=EJ310571"><span id="translatedtitle">A Practical Application of Microcomputers to Control an <span class="hlt">Active</span> <span class="hlt">Solar</span> System.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goldman, David S.; Warren, William</p> <p>1984-01-01</p> <p>Describes the design and implementation of a microcomputer-based model <span class="hlt">active</span> <span class="hlt">solar</span> heating system. Includes discussions of: (1) the <span class="hlt">active</span> <span class="hlt">solar</span> components (<span class="hlt">solar</span> collector, heat exchanger, pump, and fan necessary to provide forced air heating); (2) software components; and (3) hardware components (in the form of sensors and actuators). (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023344','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023344"><span id="translatedtitle"><span class="hlt">Solar</span> EUV Variability from FISM and SDO/EVE During <span class="hlt">Solar</span> Minimum, <span class="hlt">Active</span>, and Flaring Time Periods</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chamberlin, Phillip C.</p> <p>2011-01-01</p> <p>The Living With a Star (LWS) Focus Science Team has identified three periods of different <span class="hlt">solar</span> <span class="hlt">activity</span> levels for which they will be determining the Earth's Ionosphere and Thermosphere response. Not only will the team be comparing individual models (e.g. FLIP, T1MEGCM, GLOW) outcome driven by the various levels of <span class="hlt">solar</span> <span class="hlt">activity</span>, but the models themselves will also be compared. These models all rely on the input <span class="hlt">solar</span> EUV (0.1 -190 nm) irradiance to drive the variability. The Flare Irradiance Spectral Model (FISM) and the EUV Variability Experiment (EVE) onboard provide the <span class="hlt">Solar</span> Dynamics Observatory (SDO) provide the most accurate quantification of these irradiances. Presented and discussed are how much the <span class="hlt">solar</span> EUV irradiance changes during these three scenarios, both as a function of <span class="hlt">activity</span> and wavelength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACP....1510983P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACP....1510983P"><span id="translatedtitle"><span class="hlt">Influence</span> of the aerosol <span class="hlt">solar</span> extinction on photochemistry during the 2010 Russian wildfires episode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Péré, J. C.; Bessagnet, B.; Pont, V.; Mallet, M.; Minvielle, F.</p> <p>2015-10-01</p> <p>In this work, impact of aerosol <span class="hlt">solar</span> extinction on the photochemistry over eastern Europe during the 2010 wildfires episode is discussed for the period from 5 to 12 August 2010, which coincides to the peak of fire <span class="hlt">activity</span>. The methodology is based on an online coupling between the chemistry-transport model CHIMERE (extended by an aerosol optical module) and the radiative transfer code TUV. Results of simulations indicate an important <span class="hlt">influence</span> of the aerosol <span class="hlt">solar</span> extinction, in terms of intensity and spatial extent, with a reduction of the photolysis rates of NO2 and O3 up to 50 % (in daytime average) along the aerosol plume transport. At a regional scale, these changes in photolysis rates lead to a 3-15 % increase in the NO2 daytime concentration and to an ozone reduction near the surface of 1-12 %. The ozone reduction is shown to occur over the entire boundary layer, where aerosols are located. Also, the total aerosol mass concentration (PM10) is shown to be decreased by 1-2 %, on average during the studied period, caused by a reduced formation of secondary aerosols such as sulfates and secondary organics (4-10 %) when aerosol impact on photolysis rates is included. In terms of model performance, comparisons of simulations with air quality measurements at Moscow indicate that an explicit representation of aerosols interaction with photolysis rates tend to improve the estimation of the near-surface concentration of ozone and nitrogen dioxide as well as the formation of inorganic aerosol species such as ammonium, nitrates and sulfates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ERL.....5b1001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ERL.....5b1001B"><span id="translatedtitle">PERSPECTIVE: Low <span class="hlt">solar</span> <span class="hlt">activity</span> is blamed for winter chill over Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benestad, Rasmus E.</p> <p>2010-06-01</p> <p> the direct effect from changes in the <span class="hlt">solar</span> brightness (0.1%) was estimated to be too low to explain the temperature changes on Earth. The <span class="hlt">solar</span> <span class="hlt">influence</span> on changes in the global mean temperature has so far been found to be weak (Lean 2010, Benestad and Schmidt 2009). The important difference between recent and early studies is, however, that the latter lacked a theoretical framework based on physical mechanisms. Now we understand that stratospheric conditions vary, and are affected by chemical reactions as well as the absorption of UV light. Furthermore, we know that such variations affect temperature profiles, wave propagations, and winds (Schindell et al 2001). Lean (2010) and Haigh (2003) provide nice reviews of recent progress on <span class="hlt">solar</span>-terrestrial relationships, although questions regarding the quality of the oldest <span class="hlt">solar</span> data records are still unanswered (Benestad 2005). All these studies still rely on empirical data analysis. Much of the focus of the recent work has been on climate variation on global scales. The recent paper by Lockwood et al (2010) represents current progress, albeit that they emphasize that the relationship they identify has a regional rather than global character. Indeed, they stress that a change in the global mean temperature should not be confused with regional and seasonal means. The physical picture they provide is plausible, yet empirical relationships between <span class="hlt">solar</span> <span class="hlt">activity</span> and any of the indices describing the north Atlantic oscillation, the Arctic oscillation or the polar vortex are regarded as weak. My impression is nevertheless that the explanation provided by the Lockwood et al (2010) study reflects real aspects of our climate, especially if the effect is asymmetric. They argue that <span class="hlt">solar</span>-induced changes in the stratosphere in turn affect the occurrence of persistent wintertime blocking. But one comprehensive, definite, consistent, and convincing documentation of the entire chain causality is still not in place, due to the lack</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790042705&hterms=solar+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bhydrogen','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790042705&hterms=solar+hydrogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bhydrogen"><span id="translatedtitle">Hydrogen over helium enhancement in successive <span class="hlt">solar</span> flare particle events from the same <span class="hlt">active</span> region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Briggs, P. R.; Armstrong, T. P.; Krimigis, S. M.</p> <p>1979-01-01</p> <p>An analysis of all of the identified <span class="hlt">solar</span>-flare-associated energetic particle events in the 1972-1975 period observed with instruments aboard the IMP 7 and IMP 8 satellites has revealed at least eight occasions when more than one particle-producing flare occurred within the same McMath <span class="hlt">active</span> plage region during its transit of the visible <span class="hlt">solar</span> disk. A strong tendency for second flares to produce hydrogen over helium (p/alpha) enhanced energetic particle fluxes when compared with the first flare in the 1.8-10.0 MeV per nucleon range emerged in these multiflare regions. The p/alpha enhancement is apparently transient, and for flares separated by at least about 100 hours the p/alpha ratio tends toward its preflare value. It is suggested that the substrate plasma in an <span class="hlt">active</span> region may be enriched prior to a flare in elements heavier than hydrogen and the composition may not be significantly altered during subsequent acceleration, escape, and propagation. Thus, the preflare history of the <span class="hlt">active</span> region must be added to the list of factors <span class="hlt">influencing</span> observed <span class="hlt">solar</span>-particle-event composition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981stap....4.....Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981stap....4.....Y"><span id="translatedtitle"><span class="hlt">Solar</span> technology assessment project. Volume 4: <span class="hlt">Solar</span> air conditioning: <span class="hlt">Active</span>, hybrid and passive</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yellott, J. I.</p> <p>1981-04-01</p> <p>The status of absorption cycle <span class="hlt">solar</span> air conditioning and the Rankine cycle <span class="hlt">solar</span> cooling system is reviewed. Vapor jet ejector chillers, <span class="hlt">solar</span> pond based cooling, and photovoltaic compression air conditioning are also briefly discussed. Hybrid <span class="hlt">solar</span> cooling by direct and indirect evaporative cooling, and dehumidification by desiccation are described and discussed. Passive <span class="hlt">solar</span> cooling by convective and radiative processes, evaporative cooling by passive processes, and cooling with roof ponds and movable insulation are reviewed. Federal and state involvement in <span class="hlt">solar</span> cooling is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27479482','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27479482"><span id="translatedtitle"><span class="hlt">Influence</span> of Ancillary Ligands in Dye-Sensitized <span class="hlt">Solar</span> Cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pashaei, Babak; Shahroosvand, Hashem; Graetzel, Michael; Nazeeruddin, Mohammad Khaja</p> <p>2016-08-24</p> <p>Dye-sensitized <span class="hlt">solar</span> cells (DSSCs) have motivated many researchers to develop various sensitizers with tailored properties involving anchoring and ancillary ligands. Ancillary ligands carry favorable light-harvesting abilities and are therefore crucial in determining the overall power conversion efficiencies. The use of ancillary ligands having aliphatic chains and/or π-extended aromatic units decreases charge recombination and permits the collection of a large fraction of sunlight. This review aims to provide insight into the relationship between ancillary ligand structure and DSSC properties, which can further guide the function-oriented design and synthesis of different sensitizers for DSSCs. This review outlines how the new and rapidly expanding class of chelating ancillary ligands bearing 2,2'-bipyridyl, 1,10-phenanthroline, carbene, dipyridylamine, pyridyl-benzimidazole, pyridyl-azolate, and other aromatic ligands provides a conduit for potentially enhancing the performance and stability of DSSCs. Finally, these classes of Ru polypyridyl complexes have gained increasing interest for feasible large-scale commercialization of DSSCs due to their more favorable light-harvesting abilities and long-term thermal and chemical stabilities compared with other conventional sensitizers. Therefore, the main idea is to inspire readers to explore new avenues in the design of new sensitizers for DSSCs based on different ancillary ligands. PMID:27479482</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820009164','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820009164"><span id="translatedtitle">The combined <span class="hlt">solar</span> and tidal <span class="hlt">influence</span> in climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, P. R.</p> <p>1981-01-01</p> <p>To provide an early warning indication of the CO2 warning signal, we are searching for periodic or projectable trends in climate. The strong 20.5 year oscillation in Eastern North American January temperature found by Mock and Hibler shows evidence of a beat between waves with periods of 22.36 (22.21 to 22.55) years and 18.64 (18.45 to 18.79) years with an opposition at about 1880. These are interpreted to be the 22.279 year <span class="hlt">solar</span> Hale magnetic cycle and the 18.61 year lunar nodal tidal cycle. The lunar nodal cycle is known to produce changes in the sea surface temperature through increased mixing of the mixed layer of the ocean. This beat note is shown to be evident in the Western High Plains drought record of Mitchell, Stockton and Meko and to provide a better bit to the drought series, especially at the beat oppositions in 1880 and 1770.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AAS...197.8709S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AAS...197.8709S"><span id="translatedtitle">Real Research In The Classroom - <span class="hlt">Solar</span> <span class="hlt">Active</span> Longitudes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stagg, T.; Gearen, M.; Jacoby, S. H.; Jones, H. P.; Henney, C. J.; Hill, F.</p> <p>2000-12-01</p> <p>We present a high-school level educational/research module for a project that improves computer and analytical skills and contributes new scientific results to the field of <span class="hlt">solar</span> astronomy and physics. The module has been developed within the RET (Research Experience for Teachers) program as a new application of a cooperative project between the RBSE (Research-Based Science Education) initiative of the NSF and the NASA Education/Public Outreach program. The research goal is to improve our knowledge of the characteristics of <span class="hlt">solar</span> <span class="hlt">active</span> longitudes, where sunspots tend to cluster. In particular, the rotation rate of these regions is poorly known. It is suspected that the <span class="hlt">active</span> longitude rotation rate (ALRR) is different from the rotation rate of the <span class="hlt">solar</span> surface. If this is true, the ALRR can be compared with the internal rotation rate deduced by helioseismology providing an estimate of the <span class="hlt">active</span> region depth. A good determination of the ALRR requires the measurement of the position of thousands of individual <span class="hlt">active</span> regions, a step best done by interactive examination of images, selection of regions, and determination of heliographic position. These tasks are well-suited for high school students, who are thus provided with a motivation to improve their computer and scientific thinking skills. ScionImage (PC)/NIH Image (Macs) macros for this purpose have been developed which access a CD-ROM of 25 years of NSO/Kitt Peak magnetogram data and laboratory exercises developed previously for classroom use. In the future, a web site will be created for collecting the data from classrooms across the US, and for status reports on the results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920019627','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920019627"><span id="translatedtitle">Nonlinear techniques for forecasting <span class="hlt">solar</span> <span class="hlt">activity</span> directly from its time series</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ashrafi, S.; Roszman, L.; Cooley, J.</p> <p>1992-01-01</p> <p>Numerical techniques for constructing nonlinear predictive models to forecast <span class="hlt">solar</span> flux directly from its time series are presented. This approach makes it possible to extract dynamical invariants of our system without reference to any underlying <span class="hlt">solar</span> physics. We consider the dynamical evolution of <span class="hlt">solar</span> <span class="hlt">activity</span> in a reconstructed phase space that captures the attractor (strange), given a procedure for constructing a predictor of future <span class="hlt">solar</span> <span class="hlt">activity</span>, and discuss extraction of dynamical invariants such as Lyapunov exponents and attractor dimension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930015527','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930015527"><span id="translatedtitle">Nonlinear techniques for forecasting <span class="hlt">solar</span> <span class="hlt">activity</span> directly from its time series</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ashrafi, S.; Roszman, L.; Cooley, J.</p> <p>1993-01-01</p> <p>This paper presents numerical techniques for constructing nonlinear predictive models to forecast <span class="hlt">solar</span> flux directly from its time series. This approach makes it possible to extract dynamical in variants of our system without reference to any underlying <span class="hlt">solar</span> physics. We consider the dynamical evolution of <span class="hlt">solar</span> <span class="hlt">activity</span> in a reconstructed phase space that captures the attractor (strange), give a procedure for constructing a predictor of future <span class="hlt">solar</span> <span class="hlt">activity</span>, and discuss extraction of dynamical invariants such as Lyapunov exponents and attractor dimension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015708','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015708"><span id="translatedtitle">Wavelength Dependence of <span class="hlt">Solar</span> Flare Irradiation and its <span class="hlt">Influence</span> on the Thermosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huang, Yanshi; Richmond, Arthur D.; Deng, Yue; Qian, L.; Solomon, S.; Chamberlin, P.</p> <p>2012-01-01</p> <p>The wavelength dependence of <span class="hlt">solar</span> flare enhancement is one of the important factors determining how the Thermosphere-Ionosphere (T-I) system response to flares. To investigate the wavelength dependence of <span class="hlt">solar</span> flare, the Flare Irradiance Spectral Model (FISM) has been run for 34 X-class flares. The results show that the percentage increases of <span class="hlt">solar</span> irradiance at flare peak comparing to pre-flare condition have a clear wavelength dependence. In the wavelength range between 0 - 195 nm, it can vary from 1% to 10000%. The <span class="hlt">solar</span> irradiance enhancement is largest ( 1000%) in the XUV range (0 - 25 nm), and is about 100% in EUV range (25 - 120 nm). The <span class="hlt">influence</span> of different wavebands on the T-I system during the October 28th, 2003 flare (X17.2-class) has also been examined using the latest version of National Center for Atmospheric Research (NCAR) Thermosphere- Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). While the globally integrated <span class="hlt">solar</span> energy deposition is largest in the 0 - 14 nm waveband, the impact of <span class="hlt">solar</span> irradiance enhancement on the thermosphere at 400 km is largest for 25 - 105 nm waveband. The effect of 122 - 195 nm is small in magnitude, but it decays slowly.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSA13C..08B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSA13C..08B&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> and Magnetospheric <span class="hlt">Influence</span> on High-Frequency Radar Signal Propagation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burrell, A. G.; Yeoman, T. K.; Milan, S. E.; Lester, M.; Lawal, H. A.</p> <p>2015-12-01</p> <p>The polar ionosphere is a dynamic region that readily responds to changes in <span class="hlt">solar</span> irradiance, <span class="hlt">solar</span> wind, the magnetosphere, and the neutral atmosphere. The most recent <span class="hlt">solar</span> minimum brought to light gaps in the current understanding of the relationship between ionospheric structure and <span class="hlt">solar</span> irradiance. The Super Dual Auroral Radar Network (SuperDARN) observes the high-latitude ionosphere using coherent scatter High Frequency (HF) radars. SuperDARN has been operational over one and a half <span class="hlt">solar</span> cycles, and so provides an invaluable dataset for studying long-term ionospheric variability at the northern and southern poles. This study explores the <span class="hlt">influence</span> of <span class="hlt">solar</span> and magnetospheric forcing on HF ground-backscatter. Ground-backscatter, the backscatter that returns from a reflection point on the ground rather than from an ionospheric irregularity, provides a measure of the ionospheric density along the propagation path of the radar signal. By exploring the conditions that inhibit or enhance the propagation of ground-backscatter, we improve our understanding of the state of the bottomside ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPD....44..101P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPD....44..101P"><span id="translatedtitle"><span class="hlt">Solar</span> magnetic <span class="hlt">activity</span> cycles, coronal potential field models and eruption rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petrie, Gordon</p> <p>2013-07-01</p> <p>We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 <span class="hlt">solar</span> <span class="hlt">activity</span> cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the NSO's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun (SOLIS) vector spectro-magnetograph (VSM), the spectro-magnetograph and the 512-channel magnetograph instruments, and from the U. Stanford's Wilcox <span class="hlt">Solar</span> Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the <span class="hlt">activity</span> cycle. All non-axisymmetric multipole strengths are well correlated with the <span class="hlt">activity</span> cycle. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This <span class="hlt">influence</span> of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking (CACTus), <span class="hlt">Solar</span> Eruptive Event Detection System (SEEDS), and Nobeyama radioheliograph prominence eruption catalogs, the rate of <span class="hlt">solar</span> eruptions is found to be systematically higher for <span class="hlt">active</span> years between 2003-2012 than for those between 1997-2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ilws.conf...30C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ilws.conf...30C"><span id="translatedtitle">Theoretical model for calculation of helicity in <span class="hlt">solar</span> <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chatterjee, P.</p> <p></p> <p>We (Choudhuri, Chatterjee and Nandy, 2005) calculate helicities of <span class="hlt">solar</span> <span class="hlt">active</span> regions based on the idea of Choudhuri (2003) that poloidal flux lines get wrapped around a toroidal flux tube rising through the convection zone, thereby giving rise to the helicity. Rough estimates based on this idea compare favourably with the observed magnitude of helicity. We use our <span class="hlt">solar</span> dynamo model based on the Babcock--Leighton α-effect to study how helicity varies with latitude and time. At the time of <span class="hlt">solar</span> maximum, our theoretical model gives negative helicity in the northern hemisphere and positive helicity in the south, in accordance with observed hemispheric trends. However, we find that, during a short interval at the beginning of a cycle, helicities tend to be opposite of the preferred hemispheric trends. Next we (Chatterjee, Choudhuri and Petrovay 2006) use the above idea along with the sunspot decay model of Petrovay and Moreno-Insertis, (1997) to estimate the distribution of helicity inside a flux tube as it keeps collecting more azimuthal flux during its rise through the convection zone and as turbulent diffusion keeps acting on it. By varying parameters over reasonable ranges in our simple 1-d model, we find that the azimuthal flux penetrates the flux tube to some extent instead of being confined to a narrow sheath outside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1734d0002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1734d0002B"><span id="translatedtitle">Temperature <span class="hlt">influence</span> on wall-to-particle suspension heat transfer in a <span class="hlt">solar</span> tubular receiver</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benoit, Hadrien; López, Inmaculada Pérez; Gauthier, Daniel; Flamant, Gilles</p> <p>2016-05-01</p> <p>Dense Particle Suspension (DPS) can be used as high temperature heat transfer fluid in <span class="hlt">solar</span> receiver. Tests conducted with a one-tube experimental setup in real conditions of concentrated <span class="hlt">solar</span> irradiation resulted in determining heat transfer coefficients for the DPS flowing upward in a vertical tube. They have been obtained for solid fluxes in the range 10-45 kg/m2.s and outlet temperatures up to 1020 K. The <span class="hlt">influence</span> of solid flux, aeration and temperature is outlined in this paper. Heat transfer coefficient variations are correlated as a function of the solid flux and the temperature for given aeration conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SpWea..12...29X&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014SpWea..12...29X&link_type=ABSTRACT"><span id="translatedtitle">A statistic study of ionospheric <span class="hlt">solar</span> flare <span class="hlt">activity</span> indicator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Bo; Wan, Weixing; Ning, Baiqi; Ding, Feng; Hu, Lianhuan; Yu, You</p> <p>2014-01-01</p> <p>According to the Chapman ionization theory, an ionospheric <span class="hlt">solar</span> flare <span class="hlt">activity</span> indicator (ISFAI) is given by the <span class="hlt">solar</span> zenith angle and the variation rate of ionospheric vertical total electron content, which is measured from a global network of dual-frequency GPS receivers. The ISFAI is utilized to statistically analyze the ionospheric responses to 1439 M-class and 126 X-class <span class="hlt">solar</span> flares during <span class="hlt">solar</span> cycle 23 (1996-2008). The statistical results show that the occurrence of ISFAI peak increases obviously at 3.2 total electron content unit (TECU)/h (1 TECU = 1016 el m-2) and reaches the maximum at 10 TECU/h during M-class flares and 10 TECU/h and 40 TECU/h for X-class flares. ISFAI is closely correlated with the 26-34 nm extreme ultraviolet flux but poorly related to the 0.1-0.8 nm X-ray flux. The central meridian distance (CMD) of flare location is an important reason for depressing relationship between ISFAI and X-ray Flux. Through the CMD effect modification, the ISFAI has a significant dependence on the X-ray flux with a correlation coefficient of 0.76. The ISFAI sensitivity enables to detect the extreme X-class flares, as well as the variations of one order of magnitude or even smaller (such as for C-class flares). Meanwhile, ISFAI is helpful to the calibration of the X-ray flux at 0.1-0.8 nm observed by GOES during some flares. In addition, the statistical results demonstrate that ISFAI can detect 80% of all M-class flares and 92% for all X-class ones during 1996-2008.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AN....336..225N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AN....336..225N"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> around AD 775 from aurorae and radiocarbon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuhäuser, R.; Neuhäuser, D. L.</p> <p>2015-04-01</p> <p>A large variation in 14C around AD 775 has been considered to be caused by one or more <span class="hlt">solar</span> super-flares within one year. We critically review all known aurora reports from Europe as well as the Near, Middle, and Far East from AD 731 to 825 and find 39 likely true aurorae plus four more potential aurorae and 24 other reports about halos, meteors, thunderstorms etc., which were previously misinterpreted as aurorae or misdated; we assign probabilities for all events according to five aurora criteria. We find very likely true aurorae in AD 743, 745, 762, 765, 772, 773, 793, 796, 807, and 817. There were two aurorae in the early 770s observed near Amida (now Diyarbak\\i r in Turkey near the Turkish-Syrian border), which were not only red, but also green-yellow - being at a relatively low geomagnetic latitude, they indicate a relatively strong <span class="hlt">solar</span> storm. However, it cannot be argued that those aurorae (geomagnetic latitude 43 to 50°, considering five different reconstructions of the geomagnetic pole) could be connected to one or more <span class="hlt">solar</span> super-flares causing the 14C increase around AD 775: There are several reports about low- to mid-latitude aurorae at 32 to 44° geomagnetic latitude in China and Iraq; some of them were likely observed (quasi-)simultaneously in two of three areas (Europe, Byzantium/Arabia, East Asia), one lasted several nights, and some indicate a particularly strong geomagnetic storm (red colour and dynamics), namely in AD 745, 762, 793, 807, and 817 - always without 14C peaks. We use 39 likely true aurorae as well as historic reports about sunspots together with the radiocarbon content from tree rings to reconstruct the <span class="hlt">solar</span> <span class="hlt">activity</span>: From AD {˜ 733} to {˜ 823}, we see at least nine Schwabe cycles; instead of one of those cycles, there could be two short, weak cycles - reflecting the rapid increase to a high 14C level since AD 775, which lies at the end of a strong cycle. In order to show the end of the dearth of naked-eye sunspots, we</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IzAOP..48..738V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IzAOP..48..738V"><span id="translatedtitle">Grand minima of <span class="hlt">solar</span> <span class="hlt">activity</span> and sociodynamics of culture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vladimirsky, B. M.</p> <p>2012-12-01</p> <p>Indices of creative productivity introduced by C. Murrey were used to verify S. Ertel's conclusion about a global increase in creative productivity during the prolonged minimum of <span class="hlt">solar</span> <span class="hlt">activity</span> in 1640-1710. It was found that these indices for mathematicians, philosophers, and scientists increase in the Maunder era by factor of 1.6 in comparison with intervals of the same length before and after the minimum. A similar effect was obtained for mathematicians and philosophers for five earlier equitype minima in total (an increase by a factor of 1.9). The regularity that is revealed is confirmed by the fact that the most important achievements of high-ranking mathematicians and philosophers during the whole time period (2300 years) considered in this study fall on epochs of reduced levels of <span class="hlt">solar</span> <span class="hlt">activity</span>. The rise in the probability of the generation of rational ideas during grand minima is reflected also in the fact that they precede the appearance of written language and farming. Ultra-low-frequency electromagnetic fields appear to serve as a physical agent stimulating the <span class="hlt">activity</span> of the brain's left hemisphere during the epochs of minima.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890023784&hterms=isothermal+compression&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528%2Bisothermal%2Bcompression','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890023784&hterms=isothermal+compression&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2528%2Bisothermal%2Bcompression"><span id="translatedtitle">Magnetohydrodynamic (MHD) modelling of <span class="hlt">solar</span> <span class="hlt">active</span> phenomena via numerical methods</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, S. T.</p> <p>1988-01-01</p> <p>Numerical ideal MHD models for the study of <span class="hlt">solar</span> <span class="hlt">active</span> phenomena are summarized. Particular attention is given to the following physical phenomena: (1) local heating of a coronal loop in an isothermal and stratified atmosphere, and (2) the coronal dynamic responses due to magnetic field movement. The results suggest that local heating of a magnetic loop will lead to the enhancement of the density of the neighboring loops through MHD wave compression. It is noted that field lines can be pinched off and may form a self-contained magnetized plasma blob that may move outward into interplanetary space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790032591&hterms=solar+array+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Barray%2Bsatellite','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790032591&hterms=solar+array+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Barray%2Bsatellite"><span id="translatedtitle">Large <span class="hlt">active</span> retrodirective arrays for <span class="hlt">solar</span> power satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chernoff, R.</p> <p>1978-01-01</p> <p>An <span class="hlt">active</span> retrodirective array (ARA) transmits a beam toward the apparent source of an illuminating signal called the pilot. The array produces the RF power. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the 'conjugate' of that received by the element. Application of the ARA to the <span class="hlt">solar</span> power satellite concept has been proposed. A method of providing a reference phase is described, called 'central phasing', which eliminates the need for a rigid structure ordinarily needed in order to realize accurate retrodirectivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21135627','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21135627"><span id="translatedtitle"><span class="hlt">Influences</span> on preschool children's physical <span class="hlt">activity</span>: exploration through focus groups.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hinkley, Trina; Salmon, Jo; Okely, Anthony D; Crawford, David; Hesketh, Kylie</p> <p>2011-01-01</p> <p>This study explored mothers' perceptions of <span class="hlt">influences</span> on preschoolers' physical <span class="hlt">activity</span>. Six semistructured focus groups with 23 mothers were conducted across a range of socioeconomic position locations. Mothers identified 4 key areas of <span class="hlt">influence</span>: child fundamentals (eg, sex, personality), parent power (eg, rules, support), people to share with (eg, peers, adults), and places and things (eg, physical environments, toys). No substantial differences in themes were identified among socioeconomic position groups. <span class="hlt">Influences</span> on preschoolers' physical <span class="hlt">activity</span> are multidimensional, multifactorial, and support the use of ecological models to conceptualize and understand the <span class="hlt">influencing</span> factors. Associations among factors <span class="hlt">influencing</span> preschoolers' physical <span class="hlt">activity</span> should be further investigated through quantitative research. PMID:21135627</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5042543','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5042543"><span id="translatedtitle">Argonne <span class="hlt">Solar</span> Energy Program annual report. Summary of <span class="hlt">solar</span> program <span class="hlt">activities</span> for fiscal year 1979</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>1980-06-01</p> <p>The R and D work done at Argonne National Laboratory on <span class="hlt">solar</span> energy technologies during the period October 1, 1978 to September 30, 1979 is described. Technical areas included in the ANL <span class="hlt">solar</span> program are <span class="hlt">solar</span> energy collection, heating and cooling, thermal energy storage, ocean thermal energy conversion, photovoltaics, biomass conversion, satellite power systems, and <span class="hlt">solar</span> liquid-metal MHD power systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160006934','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160006934"><span id="translatedtitle">Eruptions that Drive Coronal Jets in a <span class="hlt">Solar</span> <span class="hlt">Active</span> Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.; Panesar, Navdeep K.; Akiyama, Sachiko; Yashiro, Seiji; Gopalswamy, Nat</p> <p>2016-01-01</p> <p><span class="hlt">Solar</span> coronal jets are common in both coronal holes and in <span class="hlt">active</span> regions (e.g., Shibata et al. 1992, Shimojo et al. 1996, Cirtain et al. 2007. Savcheva et al. 2007). Recently, Sterling et al. (2015), using data from Hinode/XRT and SDO/AIA, found that coronal jets originating in polar coronal holes result from the eruption of small-scale filaments (minifilaments). The jet bright point (JBP) seen in X-rays and hotter EUV channels off to one side of the base of the jet's spire develops at the location where the minifilament erupts, consistent with the JBPs being miniature versions of typical <span class="hlt">solar</span> flares that occur in the wake of large-scale filament eruptions. Here we consider whether <span class="hlt">active</span> region coronal jets also result from the same minifilament-eruption mechanism, or whether they instead result from a different mechanism (e.g. Yokoyama & Shibata 1995). We present observations of an on-disk <span class="hlt">active</span> region (NOAA AR 11513) that produced numerous jets on 2012 June 30, using data from SDO/AIA and HMI, and from GOES/SXI. We find that several of these <span class="hlt">active</span> region jets also originate with eruptions of miniature filaments (size scale 20'') emanating from small-scale magnetic neutral lines of the region. This demonstrates that <span class="hlt">active</span> region coronal jets are indeed frequently driven by minifilament eruptions. Other jets from the <span class="hlt">active</span> region were also consistent with their drivers being minifilament eruptions, but we could not confirm this because the onsets of those jets were hidden from our view. This work was supported by funding from NASA/LWS, NASA/HGI, and Hinode. A full report of this study appears in Sterling et al. (2016).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121..612C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121..612C"><span id="translatedtitle">North-south asymmetries in the polar thermosphere-ionosphere system: <span class="hlt">Solar</span> cycle and seasonal <span class="hlt">influences</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cnossen, Ingrid; Förster, Matthias</p> <p>2016-01-01</p> <p>Previous studies have revealed that ion drift and neutral wind speeds at ~400 km in the polar cap (>80° magnetic latitude) are on average larger in the Northern Hemisphere (NH) than in the Southern Hemisphere, which is at least partly due to asymmetry in the geomagnetic field. Here we investigate for the first time how these asymmetries depend on season and on <span class="hlt">solar</span>/geomagnetic <span class="hlt">activity</span> levels. Ion drift measurements from the Cluster mission show little seasonal dependence in their north-south asymmetry when all data (February 2001-December 2013) are used, but the asymmetry disappears around June solstice for high <span class="hlt">solar</span> <span class="hlt">activity</span> and around December solstice for low <span class="hlt">solar</span> <span class="hlt">activity</span>. Neutral wind speeds in the polar cap obtained from the Challenging Minisatellite Payload spacecraft (January 2002-December 2008) are always larger in the summer hemisphere, regardless of <span class="hlt">solar</span> <span class="hlt">activity</span>, but the high-latitude neutral wind vortices at dawn and dusk tend to be stronger in the NH, except around December solstice, in particular, when <span class="hlt">solar</span> <span class="hlt">activity</span> is low. Simulations with the Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) more or less capture the behavior of the ion drift speeds, which can be explained as a superposition of seasonal and geomagnetic field effects, with the former being stronger for higher <span class="hlt">solar</span> <span class="hlt">activity</span>. The behavior of the neutral wind speed and vorticity is not accurately captured by the model. This is probably due to an incorrect seasonal cycle in plasma density around ~400 km in CMIT, which affects the ion drag force. This must be addressed in future work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4172400','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4172400"><span id="translatedtitle">Substantial <span class="hlt">influence</span> on <span class="hlt">solar</span> energy harnessing ability by geometries of ordered Si nanowire array</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>The reflectance of the controlled periodic Si nanowire (NW) arrays is systematically explored, which characterizes the <span class="hlt">influence</span> on the <span class="hlt">solar</span> energy harnessing ability by the geometries of the NW. A unique dependence of the reflectance of the Si NW array on the diameter, the height, and the bending of the NW are disclosed. The <span class="hlt">solar</span> energy loss caused by the reflection of the Si NW array exhibits the minimum for the NW with intermediate diameter and length. A plane-wave-based transfer-matrix method (TMM) simulation is performed, which is well consistent with the experimental results. Our results demonstrate the design principle to optimize the Si NW arrays for high-efficiency <span class="hlt">solar</span> cells. PACS 81.07.-b; 78.67.-n; 81.16.-c PMID:25258613</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SpWea..12...46D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SpWea..12...46D"><span id="translatedtitle">Effects of <span class="hlt">solar</span> cycle 24 <span class="hlt">activity</span> on WAAS navigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Datta-Barua, Seebany; Walter, Todd; Bust, Gary S.; Wanner, William</p> <p>2014-01-01</p> <p>This paper reviews the effects of geomagnetic <span class="hlt">activity</span> of <span class="hlt">solar</span> cycle 24 from 2011 through mid-2013 on the Federal Aviation Administration's Wide Area Augmentation System (WAAS) navigation service in the U.S., to identify (a) major impacts and their severity compared with the previous cycle and (b) effects in new service regions of North America added since last <span class="hlt">solar</span> cycle. We examine two cases: a storm that reduced service coverage for several hours and ionospheric scintillation that led to anomalous receiver tracking. Using the 24-25 October 2011 storm as an example, we examine WAAS operational system coverage for the conterminous U.S. (CONUS). The WAAS algorithm upgrade to ionospheric estimation, in effect since late 2011, is able to mitigate the daytime coverage loss but not the nighttime loss. We correlate WAAS availability to maps of the storm plasma generated with the data assimilative model Ionospheric Data Assimilation 4-D, which show a local nighttime corotating persistent plume of plasma extending from Florida across central CONUS. We study the effect of scintillation on 9 October 2012 on the WAAS reference station at Fairbanks, Alaska. Data from a nearby scintillation monitor in Gakona and all-sky imaging of aurora at Poker Flat corroborate the event. Anomalous receiver processing triggered by scintillation reduces accuracy at Fairbanks for a few minutes. Users experiencing similar effects would have their confidence bounds inflated, possibly trading off service continuity for safety. The <span class="hlt">activity</span> to date in <span class="hlt">solar</span> cycle 24 has had minor effects on WAAS service coverage, mainly occurring in Alaska and Canada.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.1445M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.1445M"><span id="translatedtitle">On the <span class="hlt">solar</span> <span class="hlt">activity</span> variations of nocturnal F region vertical drifts covering two <span class="hlt">solar</span> cycles in the Indian longitude sector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madhav Haridas, M. K.; Manju, G.; Pant, Tarun Kumar</p> <p>2015-02-01</p> <p>A comprehensive analysis of the seasonal and <span class="hlt">solar</span> cycle variabilities of nighttime vertical drift over the Indian longitude sector is accomplished using ionosonde data located at the magnetic equatorial location, Trivandrum (8.5°N, 76.5°E). The analysis extends over a span of two decades (1988-2008). The representative seasonal variations based on the extensive data of nocturnal vertical drift during three different <span class="hlt">solar</span> <span class="hlt">activity</span> epochs is arrived at, for the first time. Seasonally, it is seen that maximum post sunset Vd is obtained in vernal equinox (VE), followed by autumnal equinox (AE), winter solstice (WS), and summer solstice (SS) for high and moderate <span class="hlt">solar</span> epochs, while for low <span class="hlt">solar</span> epoch, maximum Vd occurs in WS followed by VE, AE, and SS. Further, the role of sunset times at the magnetic conjugate points in modulating the time and magnitude of peak drifts during different <span class="hlt">solar</span> epochs is ascertained. The equinoctial asymmetry in peak Vd during high and moderate <span class="hlt">solar</span> epochs is another significant outcome of this study. The <span class="hlt">solar</span> <span class="hlt">activity</span> dependence of vertical drift for a wide range of <span class="hlt">solar</span> fluxes has been quantified for all the seasons. In the present era of GPS-based communication and navigation, these are important results that give a better handle in understanding essential factors that impact equatorial ionospheric phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AdAtS..20..934W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AdAtS..20..934W"><span id="translatedtitle">A relationship between <span class="hlt">solar</span> <span class="hlt">activity</span> and frequency of natural disasters in China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhongrui; Song, Feng; Tang, Maocang</p> <p>2003-11-01</p> <p>The relationship between the length of the <span class="hlt">solar</span> cycle, a good indicator of long-term change in <span class="hlt">solar</span> <span class="hlt">activity</span>, and natural disasters (drought, flood, and strong earthquakes) in China during the last 108 years is analyzed. The results suggest that the length of <span class="hlt">solar</span> cycle may be a useful indicator for drought/flood and strong earthquakes. When the <span class="hlt">solar</span> <span class="hlt">activity</span> strengthens, we see the length of the <span class="hlt">solar</span> cycle shorten and more floods occur in South China and frequent strong earthquakes happen in the Tibetan Plateau, but the droughts in East China as well as the strong earthquakes in Taiwan and at the western boundary of China are very few. The opposite frequencies occur when the <span class="hlt">solar</span> <span class="hlt">activity</span> weakens. The current study indicates that the <span class="hlt">solar</span> <span class="hlt">activity</span> may play an important role in the climate extremes and behavior in the lithosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1734g0003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1734g0003B"><span id="translatedtitle"><span class="hlt">Influence</span> of spatiotemporally distributed irradiance data input on temperature evolution in parabolic trough <span class="hlt">solar</span> field simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bubolz, K.; Schenk, H.; Hirsch, T.</p> <p>2016-05-01</p> <p>Concentrating <span class="hlt">solar</span> field operation is affected by shadowing through cloud movement. For line focusing systems the impact of varying irradiance has been studied before by several authors with simulations of relevant thermodynamics assuming spatially homogeneous irradiance or using artificial test signals. While today's simulation capabilities allow more and more a higher spatiotemporal resolution of plant processes there are only few studies on <span class="hlt">influence</span> of spatially distributed irradiance due to lack of available data. Based on recent work on generating real irradiance maps with high spatial resolution this paper demonstrates their <span class="hlt">influence</span> on <span class="hlt">solar</span> field thermodynamics. For a case study an irradiance time series is chosen. One <span class="hlt">solar</span> field section with several loops and collecting header is modeled for simulation purpose of parabolic trough collectors and oil as heat transfer medium. Assuming homogeneous mass flow distribution among all loops we observe spatially varying temperature characteristics. They are analysed without and with mass flow control and their impact on <span class="hlt">solar</span> field control design is discussed. Finally, the potential of distributed irradiance data is outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5513O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5513O"><span id="translatedtitle">Towards understanding the nature of any relationship between <span class="hlt">Solar</span> <span class="hlt">Activity</span> and Cosmic Rays with thunderstorm <span class="hlt">activity</span> and lightning discharge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Regan, J.; Muller, J.-P.; Matthews, S.</p> <p>2012-04-01</p> <p> both sign and significance over small geographic distances, similar to previous results [3,4,6], highlighting the complexity of the atmospheric processes contributing to the mechanism of thunderstorm generation and lightning discharge. We find correlations are generally more significant over larger timescales, as daily meteorological variability is smoothened out, suggesting a role for changing <span class="hlt">Solar</span> <span class="hlt">activity</span> levels in <span class="hlt">influencing</span> thunderstorm development and onset of lightning discharge. Comparisons of small-scale correlation results to planetary wave patterns suggests an <span class="hlt">influence</span> over the correlations of lightning <span class="hlt">activity</span> to the above indices, as proposed by Schlegel et al. [6], and previously suggested by the results of Fritz [3] and Brooks [4]. Our results show agreement with Schlegel et al. [6] for the same region over Germany, but are in disagreement with their results for Austria. This lends support to the idea of the theory of planetary waves <span class="hlt">influence</span> over correlation signs and significance across short geographic distances, as discussed by Schlegel et al. [6]. Acknowledgement: The authors wish to thank the World Wide Lightning Location Network (http://wwlln.net), a collaboration among over 50 universities and institutions (including MSSL) for providing the lightning location data used in this paper. [1] Ermakov, V.I. and Stozhkov, Yu.I., 2003. Cosmic rays in the mechanism of thundercloud production. 28th International Cosmic Ray Conference, pp. 4157-4160. [2] Kirkby, J., 2007. Cosmic rays and climate. Surv Geophys, vol. 28 (5-6) pp. 333-375. [3] Fritz, H., 1878. Die wichtigsten periodischen Erscheinungen der Meteorologie und Kosmologie. Natuurkundige Verhandelingen van de Hollandsche Maatschappij der Wetenschappen te Haarlem, Deel III, Haarlem. [4] Brooks, C.E.P., 1934. The variation of the annual frequency of thunderstorms in relation to sunspots. Quarterly Journal of the Royal Meteorological Society 60, 153-165. [5] Stringfellow, M.F., 1974. Lightning</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED395826.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED395826.pdf"><span id="translatedtitle"><span class="hlt">Solar</span> System Puzzle Kit: An <span class="hlt">Activity</span> for Earth and Space Science.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vogt, Gregory L.; Rosenberg, Carla B.</p> <p></p> <p>This <span class="hlt">Solar</span> System Puzzle Kit for grades 5-8, allows students to create an eight-cube paper puzzle of the <span class="hlt">solar</span> system and may be duplicated for classroom use or used as a take home <span class="hlt">activity</span> for children and parents. By assembling the puzzle, hand-coloring the bodies of the <span class="hlt">solar</span> system, and viewing the puzzle's 12 sides, students can reinforce…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5686762','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5686762"><span id="translatedtitle"><span class="hlt">Solar</span> Energy Education. Social studies: <span class="hlt">activities</span> and teacher's guide. Field test edition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1982-01-01</p> <p><span class="hlt">Solar</span> energy information is made available to students through classroom instruction by way of the <span class="hlt">Solar</span> Energy Education teaching manuals. In this manual <span class="hlt">solar</span> energy, as well as other energy sources like wind power, is introduced by performing school <span class="hlt">activities</span> in the area of social studies. A glossary of energy related terms is included. (BCS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720042451&hterms=magnetic+coupling&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmagnetic%2Bcoupling','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720042451&hterms=magnetic+coupling&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmagnetic%2Bcoupling"><span id="translatedtitle">Magnetic coupling of the <span class="hlt">active</span> chromosphere to the <span class="hlt">solar</span> interior.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Foukal, P.</p> <p>1972-01-01</p> <p>Evidence is summarized to show that the configuration of e lines which governs the appearance of H-alpha fine structure in <span class="hlt">active</span> regions is set mainly by motions in the subphotosphere where these lines are anchored. It is shown that H-alpha fine structure is directly coupled to a layer probably more than 5000 km below the photosphere, and little distortion of the strong fields is expected in the ines. The shorter rotation period of <span class="hlt">active</span> regions observed by Howard and others (compared to the photospheric gas) reted as a result ofthis direct coupling of the strong field to a more rapidly rotating <span class="hlt">solar</span> interior. The effects of dragging such a field through a photosphere of finite resistivity are briefly considered for features of various observed cross-sections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMNH42A..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMNH42A..05G"><span id="translatedtitle">Possible Relationship of the <span class="hlt">Solar</span> <span class="hlt">Activity</span> and Earthquakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzalez-Trejo, J. I.; Cervantes, F.; Real-Ramírez, C. A.; Hoyos-Reyes, L. F.; Miranda-Tello, R.; Area de Sistemas Computacionales</p> <p>2013-05-01</p> <p>Several authors have recently argued that there is a relationship between <span class="hlt">solar</span> <span class="hlt">activity</span> and big earthquakes. This work compares Dst index fluctuations along 2012 and 2013, with the earthquake <span class="hlt">activity</span> near La Paz, Baja California, Mexico. The earthquakes measurements at this place were divided according its deep focus. It was observed that the frequency of the deeper earthquakes increases shortly after considerable fluctuations in the Dst index are registered. We assume that the number of deep earthquakes increases because the interaction of the tectonic plate below that place and the tectonic plates in contact with it increases. This work also shows that the frequency of shallowest minor and light earthquakes increases shortly before a strongest earthquake takes place in the vicinity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27410637','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27410637"><span id="translatedtitle">Detectability of <span class="hlt">active</span> triangulation range finder: a <span class="hlt">solar</span> irradiance approach.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Huizhe; Gao, Jason; Bui, Viet Phuong; Liu, Zhengtong; Lee, Kenneth Eng Kian; Peh, Li-Shiuan; Png, Ching Eng</p> <p>2016-06-27</p> <p><span class="hlt">Active</span> triangulation range finders are widely used in a variety of applications such as robotics and assistive technologies. The power of the laser source should be carefully selected in order to satisfy detectability and still remain eye-safe. In this paper, we present a systematic approach to assess the detectability of an <span class="hlt">active</span> triangulation range finder in an outdoor environment. For the first time, we accurately quantify the background noise of a laser system due to <span class="hlt">solar</span> irradiance by coupling the Perez all-weather sky model and ray tracing techniques. The model is validated with measurements with a modeling error of less than 14.0%. Being highly generic and sufficiently flexible, the proposed model serves as a guide to define a laser system for any geographical location and microclimate. PMID:27410637</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25252341','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25252341"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span> water disinfection on immunity against cholera - a review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ssemakalu, Cornelius Cano; Ubomba-Jaswa, Eunice; Motaung, Keolebogile Shirley; Pillay, Michael</p> <p>2014-09-01</p> <p>Cholera remains a problem in developing countries. This is attributed to the unavailability of proper water treatment, sanitary infrastructure and poor hygiene. As a consequence, countries facing cholera outbreaks rely on interventions such as the use of oral rehydration therapy and antibiotics to save lives. In addition to vaccination, the provision of chlorine tablets and hygiene sensitization drives have been used to prevent new cholera infections. The implementation of these interventions remains a challenge due to constraints associated with the cost, ease of use and technical knowhow. These challenges have been reduced through the use of <span class="hlt">solar</span> water disinfection (SODIS). The success of SODIS in mitigating the risk associated with the consumption of waterborne pathogens has been associated with <span class="hlt">solar</span> irradiation. This has prompted a lot of focus on the <span class="hlt">solar</span> component for enhanced disinfection. However, the role played by the host immune system following the consumption of <span class="hlt">solar</span>-irradiated water pathogens has not received any significant attention. The mode of inactivation resulting from the exposure of microbiologically contaminated water results in immunologically important microbial states as well as components. In this review, the possible <span class="hlt">influence</span> that <span class="hlt">solar</span> water disinfection may have on the immunity against cholera is discussed. PMID:25252341</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA43C..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA43C..06H"><span id="translatedtitle">Wavelength dependence of <span class="hlt">solar</span> flare irradiance enhancement and its <span class="hlt">influence</span> on the thermosphere-ionosphere system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Y.; Richmond, A. D.; Deng, Y.; Qian, L.; Solomon, S. C.; Chamberlin, P. C.</p> <p>2012-12-01</p> <p>The wavelength dependence of irradiance enhancement during <span class="hlt">solar</span> flare is one of the important factors in determining how the Thermosphere-Ionosphere (T-I) system responds to flares. To investigate the wavelength dependence of irradiance, the Flare Irradiance Spectral Model (FISM) was run for 34 X-class flares. The results show that the percentage increases of <span class="hlt">solar</span> irradiance at flare peak have a clear wavelength dependence. In the wavelength range between 0 - 195 nm, it can vary from 1% to 10000%. The <span class="hlt">solar</span> irradiance enhancement is largest (~1000%) in the XUV range (0 - 25 nm), and is about 100% in the EUV range (25 - 120 nm). The <span class="hlt">influence</span> of different wavebands on the T-I system during the October 28th, 2003 flare (X17.2-class) has also been examined using the latest version of the National Center for Atmospheric Research (NCAR) Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). While the enhancement of the globally integrated <span class="hlt">solar</span> energy deposition is largest in the 0 - 14 nm waveband, the impact of <span class="hlt">solar</span> irradiance enhancement on the thermosphere at 400km is largest for the 25 - 105 nm waveband. The effect of the enhancement of the 122 - 195 nm waveband is small in magnitude, but it decays slowly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......175D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......175D"><span id="translatedtitle">High resolution studies of complex <span class="hlt">solar</span> <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deng, Na</p> <p></p> <p>Flares and Coronal Mass Ejections (CMEs) are energetic events, which can even impact the near-Earth environment and are the principal source of space weather. Most of them originate in <span class="hlt">solar</span> <span class="hlt">active</span> regions. The most violent events are produced in sunspots with a complex magnetic field topology. Studying their morphology and dynamics is helpful in understanding the energy accumulation and release mechanisms for flares and CMEs, which are intriguing problems in <span class="hlt">solar</span> physics. The study of complex <span class="hlt">active</span> regions is based on high-resolution observations from space missions and new instruments at the Big Bear <span class="hlt">Solar</span> Observatory (BBSO). Adaptive optics (AO) in combination with image restoration techniques (speckle masking imaging) can achieve improved image quality and a spatial resolution (about 100 km on the <span class="hlt">solar</span> surface) close to the diffraction limit of BBSO's 65 cm vacuum telescope. Dopplergrams obtained with a two-dimensional imaging spectrometer combined with horizontal flow maps derived with Local Correlation Tracking (LCT) provide precise measurements of the three-dimensional velocity field in sunspots. Magnetic field measurements from ground- and space-based instruments complement these data. At the outset of this study, the evolution and morphology of a typical round sunspot are described in some detail. The sunspot was followed from disk center to the limb, thus providing some insight into the geometry of the magnetic flux system. Having established a benchmark for a stable sunspot, the attention is turned to changes of the sunspot structure associated with flares and CMEs. Rapid penumbral decay and the strengthening of sunspot umbrae are manifestations of photospheric magnetic field changes after a flare. These sudden intensity changes are interpreted as a result of magnetic reconnection during the flare, which causes the magnetic field lines to be turned from more inclined to more vertical. Strong photospheric shear flows along the flaring magnetic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70034109','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70034109"><span id="translatedtitle">Spring-fall asymmetry of substorm strength, geomagnetic <span class="hlt">activity</span> and <span class="hlt">solar</span> wind: Implications for semiannual variation and <span class="hlt">solar</span> hemispheric asymmetry</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mursula, K.; Tanskanen, E.; Love, J.J.</p> <p>2011-01-01</p> <p>We study the seasonal variation of substorms, geomagnetic <span class="hlt">activity</span> and their <span class="hlt">solar</span> wind drivers in 1993-2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic <span class="hlt">activity</span> show a dominant annual variation, with equinoctial maxima alternating between Spring in <span class="hlt">solar</span> cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the <span class="hlt">solar</span> wind. A similar, large annual variation is found in the <span class="hlt">solar</span> wind driver of substorms and geomagnetic <span class="hlt">activity</span>, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic <span class="hlt">activity</span> is not due to ionospheric conditions but to a hemispherically asymmetric distribution of <span class="hlt">solar</span> wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic <span class="hlt">activity</span> has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of <span class="hlt">solar</span> magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future. Copyright ?? 2011 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.agu.org/pubs/crossref/2011/2011GL046751.shtml','USGSPUBS'); return false;" href="http://www.agu.org/pubs/crossref/2011/2011GL046751.shtml"><span id="translatedtitle">Spring-fall asymmetry of substorm strength, geomagnetic <span class="hlt">activity</span> and <span class="hlt">solar</span> wind: Implications for semiannual variation and <span class="hlt">solar</span> hemispheric asymmetry</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Marsula, K.; Tanskanen, E.; Love, J.J.</p> <p>2011-01-01</p> <p>We study the seasonal variation of substorms, geomagnetic <span class="hlt">activity</span> and their <span class="hlt">solar</span> wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic <span class="hlt">activity</span> show a dominant annual variation, with equinoctial maxima alternating between Spring in <span class="hlt">solar</span> cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the <span class="hlt">solar</span> wind. A similar, large annual variation is found in the <span class="hlt">solar</span> wind driver of substorms and geomagnetic <span class="hlt">activity</span>, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic <span class="hlt">activity</span> is not due to ionospheric conditions but to a hemispherically asymmetric distribution of <span class="hlt">solar</span> wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic <span class="hlt">activity</span> has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of <span class="hlt">solar</span> magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750008353&hterms=activity+Physics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dactivity%2BPhysics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750008353&hterms=activity+Physics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dactivity%2BPhysics"><span id="translatedtitle"><span class="hlt">Solar</span> and terrestrial physics. [effects of <span class="hlt">solar</span> <span class="hlt">activities</span> on earth environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1975-01-01</p> <p>The effects of <span class="hlt">solar</span> radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the <span class="hlt">solar</span> cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of <span class="hlt">solar</span> cycle variation of the characteristics of the <span class="hlt">solar</span> wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of <span class="hlt">solar</span> shock waves are investigated. The <span class="hlt">solar</span> and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860008385','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860008385"><span id="translatedtitle"><span class="hlt">Influence</span> of design variables on radiation hardness of silicon MINP <span class="hlt">solar</span> cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, W. A.; Solaun, S.; Rao, B. B.; Banerjee, S.</p> <p>1985-01-01</p> <p>Metal-insulator-N/P silicon (MINP) <span class="hlt">solar</span> cells were fabricated using different substrate resistivity values, different N-layer designs, and different I-layer designs. A shallow junction into an 0.3 ohm-cm substrate gave best efficiency whereas a deeper junction into a 1 to 4 ohm-cm substrate gave improved radiation hardness. I-layer design variation did little to <span class="hlt">influence</span> radiation hardness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1613459P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1613459P"><span id="translatedtitle"><span class="hlt">Influence</span> of synoptic weather patterns on <span class="hlt">solar</span> irradiance variability in Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parding, Kajsa; Hinkelman, Laura; Liepert, Beate; Ackerman, Thomas; Dagestad, Knut-Frode; Asle Olseth, Jan</p> <p>2014-05-01</p> <p><span class="hlt">Solar</span> radiation is important for many aspects of existence on Earth, including the biosphere, the hydrological cycle, and creatures living on the planet. Previous studies have reported decadal trends in observational records of surface shortwave (SW) irradiance around the world, too strong to be caused by varying <span class="hlt">solar</span> output. These observed decadal trends have been dubbed "<span class="hlt">solar</span> dimming and brightening" and are believed to be related to changes in atmospheric aerosols and cloud cover. Because the observed <span class="hlt">solar</span> variability coincides with qualitative air pollution histories, the dimming and brightening have become almost synonymous with shortwave attenuation by anthropogenic aerosols. However, there are indications that atmospheric circulation patterns have <span class="hlt">influenced</span> the dimming and brightening in some regions, e.g., Alaska and Scandinavia. In this work, we focus on the role of atmospheric circulation patterns in modifying shortwave irradiance. An examination of European SW irradiance data from the Global Energy Balance Archive (GEBA) shows that while there are periods of predominantly decreasing (~1970-1985) and increasing (~1985-2007) SW irradiance, the changes are not spatially uniform within Europe and in a majority of locations not statistically significant. To establish a connection between weather patterns and sunshine, regression models of SW irradiance are fitted using a daily classification of European weather called Grosswetterlagen (GWL). The GWL reconstructions of shortwave irradiance represent the part of the <span class="hlt">solar</span> variability that is related to large scale weather patterns, which should be effectively separated from the <span class="hlt">influence</span> of varying anthropogenic aerosol emissions. The correlation (R) between observed and reconstruced SW irradiance is between 0.31 and 0.75, depending on station and season, all statistically significant (p<0.05, estimated with a bootstrap test). In central and eastern parts of Europe, the observed decadal SW variability is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810023565','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810023565"><span id="translatedtitle">Chromospheric and photospheric evolution of an extremely <span class="hlt">active</span> <span class="hlt">solar</span> region in <span class="hlt">solar</span> cycle 19</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mckenna-Lawlor, S. M. P.</p> <p>1981-01-01</p> <p>a comprehensive investigation was made of phenomena attending the disk passage, July 7 to 21, 1959, of <span class="hlt">active</span> <span class="hlt">solar</span> center HAO-59Q. At the photospheric level that comprised an aggregate of groups of sunspots of which one group, Mt. Wilson 14284, showed all the attributes deemed typical of <span class="hlt">solar</span> regions associated with the production of major flares. A special characteristic of 59Q was its capability to eject dark material. Part of this material remained trapped in the strong magnetic fields above group 14284 where it formed a system of interrelated arches, the legs of which passed through components of the bright chromospheric network of the plage and were rooted in various underlying umbrae. Two apparently diffeent kinds of flare were identified in 59Q; namely, prominence flares (which comprised brightenings within part of the suspended dark prominence) and plage flares (which comprised brightenings within part of the chromospheric network). Prominence flares were of three varieties described as 'impact', 'stationary' and 'moving' prominence flares. Plage flares were accompanied in 3 percent of cases by Type III bursts. These latter radio events indicate the associated passage through the corona of energetic electrons in the approximate energy range 10 to 100 keV. At least 87.5 percent, and probably all, impulsive brightenings in 59Q began directly above minor spots, many of which satellites to major umbrae. Stationary and moving prominence flares were individually triggered at sites beneath which magnetic changes occurred within intervals which included each flare's flash phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5867800','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5867800"><span id="translatedtitle">Chromospheric and photospheric evolution of an extremely <span class="hlt">active</span> <span class="hlt">solar</span> region in <span class="hlt">solar</span> cycle 19</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mckenna-Lawlor, S.M.P.</p> <p>1981-08-01</p> <p>a comprehensive investigation was made of phenomena attending the disk passage, July 7 to 21, 1959, of <span class="hlt">active</span> <span class="hlt">solar</span> center HAO-59Q. At the photospheric level that comprised an aggregate of groups of sunspots of which one group, Mt. Wilson 14284, showed all the attributes deemed typical of <span class="hlt">solar</span> regions associated with the production of major flares. A special characteristic of 59Q was its capability to eject dark material. Part of this material remained trapped in the strong magnetic fields above group 14284 where it formed a system of interrelated arches, the legs of which passed through components of the bright chromospheric network of the plage and were rooted in various underlying umbrae. Two apparently diffeent kinds of flare were identified in 59Q namely, prominence flares (which comprised brightenings within part of the suspended dark prominence) and plage flares (which comprised brightenings within part of the chromospheric network). Prominence flares were of three varieties described as 'impact', 'stationary' and 'moving' prominence flares. Plage flares were accompanied in 3 percent of cases by Type III bursts. These latter radio events indicate the associated passage through the corona of energetic electrons in the approximate energy range 10 to 100 keV. At least 87.5 percent, and probably all, impulsive brightenings in 59Q began directly above minor spots, many of which satellites to major umbrae. Stationary and moving prominence flares were individually triggered at sites beneath which magnetic changes occurred within intervals which included each flare's flash phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780015051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780015051"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> during Skylab: Its distribution and relation to coronal holes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Speich, D. M.; Smith, J. B., Jr.; Wilson, R. M.; Mcintosh, P. S.</p> <p>1978-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">active</span> regions observed during the period of Skylab observations (May 1973-February 1974) were examined for properties that varied systematically with location on the sun, particularly with respect to the location of coronal holes. Approximately 90 percent of the optical and X-ray flare <span class="hlt">activity</span> occurred in one <span class="hlt">solar</span> hemisphere (136-315 heliographic degrees longitude). <span class="hlt">Active</span> regions within 20 heliographic degrees of coronal holes were below average in lifetimes, flare production, and magnetic complexity. Histograms of <span class="hlt">solar</span> flares as a function of <span class="hlt">solar</span> longitude were aligned with H alpha synoptic charts on which <span class="hlt">active</span> region serial numbers and coronal hole boundaries were added.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSMSA31A..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMSA31A..05M"><span id="translatedtitle">Equatorial Total Electron Content (TEC) at Low and High <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mene, M. N.; Obrou, O. K.; Kobea, A. T.; Zaka, K. Z.</p> <p>2007-05-01</p> <p>Total Electron Content derived from ionosonde data recorded at Korhogo (Lat=9.33 N, Long =5.43 W, Dip = 0.67 S) are compared to the Internatial Reference Ionosphere (IRI) model predicted TEC for high (1999) and low (1994) <span class="hlt">solar</span> <span class="hlt">activity</span> conditions. The result shows that the TEC has a <span class="hlt">solar</span> <span class="hlt">activity</span> and seasonal dependence. The IRI predicted values are closer to the observed TEC at high <span class="hlt">solar</span> <span class="hlt">activity</span>. However, at low <span class="hlt">solar</span> <span class="hlt">activity</span> the IRI overestimates the observed TEC. The deviation is more prominent in equinox during the time range 0900 to 2300 local time. The deviation is estimated to 60% of the observed TEC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870057220&hterms=balance+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dbalance%2Benergy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870057220&hterms=balance+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dbalance%2Benergy"><span id="translatedtitle">Energy balance in <span class="hlt">solar</span> <span class="hlt">active</span> regions - The dip of April, 1985</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hudson, H. S.</p> <p>1986-01-01</p> <p>The presence of a <span class="hlt">solar</span> <span class="hlt">active</span> region affects the luminosity of the sun. Sunspots directly produce 'dips' in the total <span class="hlt">solar</span> irradiance approximately proportionally to their projected area, while faculae produce excess energy. These effects were discovered during the <span class="hlt">solar</span> maximum period of 1980, and the sunspot effect during <span class="hlt">solar</span> minimum is examined. The 'dip' due to an <span class="hlt">active</span> region in April, 1985, as observed in the total <span class="hlt">solar</span> irradiance by the ACRIM instrument on the <span class="hlt">Solar</span> Maximum Mission is examined. These data (obtained after the spacecraft repair in May, 1984) have simple variations, relative to those observed in 1980, because of the reduced level of <span class="hlt">activity</span> approaching <span class="hlt">solar</span> minimum. It is found that the PSI index of projected sunspot area as defined in 1980 appears to describe this 'dip' satisfactorily.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.8163G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.8163G&link_type=ABSTRACT"><span id="translatedtitle">Gravity wave <span class="hlt">activity</span> in the thermosphere inferred from GOCE data, and its dependence on <span class="hlt">solar</span> flux conditions.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia, Raphael F.; Bruinsma, Sean; Doornbos, Eelco; Massarweh, Lotfi</p> <p>2016-04-01</p> <p>This study is focused on the effect of <span class="hlt">solar</span> flux conditions on the dynamics of Gravity Waves (GW) in thermosphere. Air density and cross-wind in situ estimates from the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) accelerometers are analyzed for the whole mission duration. The analysis was performed in the Fourier spectral domain averaging spectral results over periods of 2 months close to solstices. First the Amplitude Spectral Density (ASD) and the Magnitude Squared Coherence (MSC) of physical parameters are linked to local gravity waves. Then, a new GW marker (called Cf3) was introduced here to constrain GWs <span class="hlt">activity</span> under Low, Medium and High <span class="hlt">solar</span> flux conditions, showing a clear <span class="hlt">solar</span> dumping effect on GW <span class="hlt">activity</span>. Most of GW signal has been found in a spectral range above 8 mHz in GOCE data, meaning a maximum horizontal wavelength around 1000 km. The level GW <span class="hlt">activity</span> at GOCE altitude is strongly decreasing with increasing <span class="hlt">solar</span> flux. Furthermore, a shift in the dominant frequency with <span class="hlt">solar</span> flux conditions has been noted, leading to a larger horizontal wavelengths (from 200 to 500 km) during high <span class="hlt">solar</span> flux conditions. The <span class="hlt">influence</span> of correlated error sources, between air density and cross-winds, is discussed. Consistency of the spectral domain results has been verified in time-domain with a global mapping of high frequency perturbations along GOCE orbit. This analysis shows a clear dependence with geomagnetic latitude with strong perturbations at magnetic poles, and an extension to lower latitudes favoured by low <span class="hlt">solar</span> <span class="hlt">activity</span> conditions. Various possible causes of this spatial trend are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016041','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016041"><span id="translatedtitle">Near-Earth <span class="hlt">Solar</span> Wind Flows and Related Geomagnetic <span class="hlt">Activity</span> During more than Four <span class="hlt">Solar</span> Cycles (1963-2011)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, Ian G.; Cane, Hilary V.</p> <p>2012-01-01</p> <p>In past studies, we classified the near-Earth <span class="hlt">solar</span> wind into three basic flow types based on inspection of <span class="hlt">solar</span> wind plasma and magnetic field parameters in the OMNI database and additional data (e.g., geomagnetic indices, energetic particle, and cosmic ray observations). These flow types are: (1) High-speed streams associated with coronal holes at the Sun, (2) Slow, interstream <span class="hlt">solar</span> wind, and (3) Transient flows originating with coronal mass ejections at the Sun, including interplanetary coronal mass ejections and the associated upstream shocks and post-shock regions. The <span class="hlt">solar</span> wind classification in these previous studies commenced with observations in 1972. In the present study, as well as updating this classification to the end of 2011, we have extended the classification back to 1963, the beginning of near-Earth <span class="hlt">solar</span> wind observations, thereby encompassing the complete <span class="hlt">solar</span> cycles 20 to 23 and the ascending phase of cycle 24. We discuss the cycle-to-cycle variations in near-Earth <span class="hlt">solar</span> wind structures and l1e related geomagnetic <span class="hlt">activity</span> over more than four <span class="hlt">solar</span> cycles, updating some of the results of our earlier studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21460135','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21460135"><span id="translatedtitle">SIMULATION OF THE FORMATION OF A <span class="hlt">SOLAR</span> <span class="hlt">ACTIVE</span> REGION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cheung, M. C. M.; Title, A. M.; Rempel, M.; Schuessler, M.</p> <p>2010-09-01</p> <p>We present a radiative magnetohydrodynamics simulation of the formation of an <span class="hlt">active</span> region (AR) on the <span class="hlt">solar</span> surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the <span class="hlt">solar</span> photosphere. The rise of the magnetic plasma in the convection zone is accompanied by predominantly horizontal expansion. Such an expansion leads to a scaling relation between the plasma density and the magnetic field strength such that B {proportional_to} rhov{sup 1/2}. The emergence of magnetic flux into the photosphere appears as a complex magnetic pattern, which results from the interaction of the rising magnetic field with the turbulent convective flows. Small-scale magnetic elements at the surface first appear, followed by their gradual coalescence into larger magnetic concentrations, which eventually results in the formation of a pair of opposite polarity spots. Although the mean flow pattern in the vicinity of the developing spots is directed radially outward, correlations between the magnetic field and velocity field fluctuations allow the spots to accumulate flux. Such correlations result from the Lorentz-force-driven, counterstreaming motion of opposite polarity fragments. The formation of the simulated AR is accompanied by transient light bridges between umbrae and umbral dots. Together with recent sunspot modeling, this work highlights the common magnetoconvective origin of umbral dots, light bridges, and penumbral filaments.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6464414','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6464414"><span id="translatedtitle"><span class="hlt">Active-solar</span>-energy-system materials research priorities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Herzenberg, S.A.; Hien, L.K.; Silberglitt, R.</p> <p>1983-01-01</p> <p>THis report describes and prioritizes materials research alternatives to improve <span class="hlt">active</span> <span class="hlt">solar</span> heating and cooling system cost-effectiveness. Materials research areas analyzed are (polymer) glazings, heat mirrors, (selective) absorber surfaces, absorber adhesives, absorber substrates, fluids, thermal storage materials, and desiccants. Three classes of <span class="hlt">solar</span> collectors are considered in the cost-effectiveness analysis: medium-temperature flat-plate collectors (operating temperature, 70/sup 0/C); high-temperature flat-plate collectors (operating temperature, 70 to 120/sup 0/C); and evacuated tubes (operating temperature 70 to 230/sup 0/C). We found the highest priority for medium-temperature flat-plate collectors to be research on polymeric materials to improve performance and durability characteristics. For the high-temperature, flat-plate collectors and evacuated tubes, heat mirror and selective absorber research is the highest priority. Research on storage materials, fluids, and desiccants is of relatively low priority for improving cost-effectiveness in all cases. The highest priority materials research areas identified include: optical properties and degradation of transparent conducting oxide heat mirrors and thickness insensitive selective paints; uv and thermal stabilization of polymeric glazing materials; and systems analysis of integrated polymeric collectors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9152E..22L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9152E..22L"><span id="translatedtitle">A complete <span class="hlt">solar</span> eruption <span class="hlt">activity</span> processing tool with robotization and real time (II)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Ganghua; Zhao, Cui; Yang, Xiao</p> <p>2014-07-01</p> <p>Intense <span class="hlt">solar</span> <span class="hlt">active</span> events have made significant impacts on the modern high technology system and living environment of human being, therefore <span class="hlt">solar</span> <span class="hlt">activities</span> forecast and space weather forecast are getting more and more attention. Meanwhile, data volume acquisitioned by <span class="hlt">solar</span> monitor facility is growing larger and larger due to the requirement of multiple dimensions observation and high temporal and spatial resolution. As staffs of a <span class="hlt">solar</span> monitor data producer, we are encouraged to adopt new techniques and methods to provide valuable information to <span class="hlt">solar</span> <span class="hlt">activities</span> forecast organization and the other related users, and provide convenient products and tools to the users. In the previous paper "A complete <span class="hlt">solar</span> eruption <span class="hlt">activities</span> processing tool with robotization and real time (I)", we presented a fully automatic and real time detecting architecture for different <span class="hlt">solar</span> erupt <span class="hlt">activities</span>. In this paper, we present new components of new data sets in the architecture design, latest progresses on automatic recognition of <span class="hlt">solar</span> flare, filament and magnetic field, and a newly introduced method with which <span class="hlt">solar</span> photospheric magnetic nonpotentiality parameters are processed in real time, then its result directly can be used in <span class="hlt">solar</span> <span class="hlt">active</span> forecast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=physical+AND+availability&pg=5&id=EJ834363','ERIC'); return false;" href="http://eric.ed.gov/?q=physical+AND+availability&pg=5&id=EJ834363"><span id="translatedtitle">Factors <span class="hlt">Influencing</span> Cypriot Children's Physical <span class="hlt">Activity</span> Levels</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Loucaides, Constantinos A.; Chedzoy, Sue M.</p> <p>2005-01-01</p> <p>The purpose of this paper is to present selected findings from a larger study, which set out to examine the physical <span class="hlt">activity</span> levels of Cypriot primary school children and determinants of their <span class="hlt">activity</span>. Twenty parents of children who obtained high and low <span class="hlt">activity</span> scores based on pedometer counts and self-reports scores were interviewed. By…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.8125F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.8125F"><span id="translatedtitle">How does clear-sky terrestrial irradiance vary with <span class="hlt">solar</span> <span class="hlt">activity</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feulner, Georg</p> <p>2013-04-01</p> <p>I investigate recent claims for a strong variation of clear-sky terrestrial <span class="hlt">solar</span> irradiance with <span class="hlt">solar</span> <span class="hlt">activity</span> (on the level of O(1%) over the 11-year cycle) derived from ground-based observations of the Sun. As it turns out, these erroneous results arise because important effects like the dimming by volcanic aerosols and long-term changes in atmospheric transmission independent of <span class="hlt">solar</span> <span class="hlt">activity</span> have to be corrected for. After taking these into account, clear-sky terrestrial <span class="hlt">solar</span> irradiance can be shown to vary by O(0.1%) as expected from satellite-based measurements of the changes in Total <span class="hlt">Solar</span> Irradiance over the <span class="hlt">solar</span> cycle. On the one hand this example illustrates the usefulness of ground-based monitoring of <span class="hlt">solar</span> irradiance data, but on the other hand it highlights the difficulties which can hamper an unbiased analysis of such datasets. References Feulner, G., 2011: The Smithsonian <span class="hlt">solar</span> constant data revisited: no evidence for a strong effect of <span class="hlt">solar</span> <span class="hlt">activity</span> in ground-based insolation data, Atmos. Chem. Phys., 11, 3291-3301, doi:10.5194/acp-11-3291-2011 Feulner, G., 2013: On the relation between <span class="hlt">solar</span> <span class="hlt">activity</span> and clear-sky terrestrial irradiance, <span class="hlt">Solar</span> Phys., 282, 615-627, doi:10.1007/s11207-012-0129-z</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960028765','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960028765"><span id="translatedtitle">Observing large-scale <span class="hlt">solar</span> surface flows with GONG: Investigation of a key element in <span class="hlt">solar</span> <span class="hlt">activity</span> buildup</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beck, John G.; Simon, George W.; Hathaway, David H.</p> <p>1996-01-01</p> <p>The Global Oscillation Network Group (GONG) <span class="hlt">solar</span> telescope network has begun regular operations, and will provide continuous Doppler images of large-scale nearly-steady motions at the <span class="hlt">solar</span> surface, primarily those due to supergranulation. Not only the Sun's well-known magnetic network, but also flux diffusion, dispersal, and concentration at the surface appear to be controlled by supergranulation. Through such magnetoconvective interactions, magnetic stresses develop, leading to <span class="hlt">solar</span> <span class="hlt">activity</span>. We show a Doppler movie made from a 45.5 hr time series obtained 1995 May 9-10 using data from three of the six GONG sites (Learmonth, Tenerife, Tucson), to demonstrate the capability of this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006IAUJD...8E...5B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006IAUJD...8E...5B"><span id="translatedtitle">Long-term Fluctuations in The Earth's Rotation And <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banjevic, Boris</p> <p>2006-08-01</p> <p>The tidal friction is not the only cause to <span class="hlt">influence</span> the earth's rotation in long term. There is a correlation between <span class="hlt">solar</span> <span class="hlt">activity</span> and long term variations of the Earth's rotation. Possible cause is an interaction between <span class="hlt">solar</span> wind and magnetosphere of the earth. This would produce the angular deceleration of earth's rotation. Long-term fluctuation in the length of the day (LOD) with semi-amplitude of ca. 4 ms and a period of ca. 1480 years may exist. One cause is probably electromagnetic core-mantle coupling. Ice-rafting event during Holocene is found with cyclity of 1470 years. There is also possible connection between <span class="hlt">solar</span> <span class="hlt">activity</span> identified in delta ^14C records of 1450 year periodicity and cyclity of the Earth's rotation. Global-sea level changes associated with climatic variations may produce significant effect on long timescales. The non-tidal acceleration may be connected with the rate of change in Earth's oblateness, attributed to viscous rebound of the Earth from the decrease in load in the polar caps following last deglaciation. The average of Earth's dynamic oblateness (J2 dot) for the past 4000 years is larger than the present J2 (dot) from satellite laser ranging, - 2.8x10^-11/yr. Current increase of LOD is on the average by 1.8+/-0.1 milliseconds per century (ms/ cy). According to early Chinese and Babylonian eclipses from 2000-700 BC we obtain an average of LOD 1.67+/-0.05 ms/cy (1820 AD), which is lower than current value. This is very important for evaluating ancient eclipses before 700 BC. We have used singular spectrum analysis, Catterpilar method, to find periodicities from time series of LOD. We have also founded highly correlated relationship between the periods of low <span class="hlt">solar</span> <span class="hlt">activity</span> and LOD at centennial time scales. Our calculation before 700 BC implies sudden change of rotation between 850-750 BC. Major increases of ^14C in the atmosphere at ca. 750 BC (Homer minimum) and ca. 1650 AD (Maunder minimum) are caused by the reduction of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22127133','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22127133"><span id="translatedtitle">MAGNETIC STRUCTURE PRODUCING X- AND M-CLASS <span class="hlt">SOLAR</span> FLARES IN <span class="hlt">SOLAR</span> <span class="hlt">ACTIVE</span> REGION 11158</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Inoue, S.; Magara, T.; Choe, G. S.; Hayashi, K.; Shiota, D.</p> <p>2013-06-10</p> <p>We study the three-dimensional magnetic structure of the <span class="hlt">solar</span> <span class="hlt">active</span> region 11158, which produced one X-class and several M-class flares on 2011 February 13-16. We focus on the magnetic twist in four flare events, M6.6, X2.2, M1.0, and M1.1. The magnetic twist is estimated from the nonlinear force-free field extrapolated from the vector fields obtained from the Helioseismic and Magnetic Imager on board the <span class="hlt">Solar</span> Dynamic Observatory using the magnetohydrodynamic relaxation method developed by Inoue et al. We found that strongly twisted lines ranging from half-turn to one-turn twists were built up just before the M6.6 and X2.2 flares and disappeared after that. Because most of the twists remaining after these flares were less than a half-turn twist, this result suggests that the buildup of magnetic twist over the half-turn twist is a key process in the production of large flares. On the other hand, even though these strong twists were also built up just before the M1.0 and M1.1 flares, most of them remained afterward. Careful topological analysis before the M1.0 and M1.1 flares shows that the strongly twisted lines were surrounded mostly by the weakly twisted lines formed in accordance with the clockwise motion of the positive sunspot, whose footpoints are rooted in strong magnetic flux regions. These results imply that these weakly twisted lines might suppress the <span class="hlt">activity</span> of the strongly twisted lines in the last two M-class flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850021587&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850021587&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529"><span id="translatedtitle">Inferred flows of electric currents in <span class="hlt">solar</span> <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ding, Y. J.; Hong, Q. F.; Hagyard, M. J.; Deloach, A. C.</p> <p>1985-01-01</p> <p>Techniques to identify sources of major current systems in <span class="hlt">active</span> regions and their channels of flow are explored. Measured photospheric vector magnetic fields together with high resolution white light and H-alpha photographs provide the data base to derive the current systems in the photosphere and chromosphere of a <span class="hlt">solar</span> <span class="hlt">active</span> region. Simple mathematical constructions of <span class="hlt">active</span> region fields and currents are used to interpret these data under the assumptions that the fields in the lower atmosphere (below 200 km) may not be force free but those in the chromosphere and higher are. The results obtained for the complex <span class="hlt">active</span> region AR 2372 are: (1) Spots exhibiting significant spiral structure in the penumbral filaments were the source of vertical currents at the photospheric surface; (2) Magnetic neutral lines where the transverse magnetic field was strongly sheared were channels along which a strong current system flowed; (3) The inferred current systems produced a neutral sheet and oppositely-flowing currents in the area of the magnetic delta configuration that was the site of flaring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997EOSTr..78..145S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997EOSTr..78..145S"><span id="translatedtitle">19th century auroral observations reveal <span class="hlt">solar</span> <span class="hlt">activity</span> patterns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silverman, Sam</p> <p></p> <p>Growing interest in the aurora in the early part of the eighteenth century, which resulted from the spectacular reappearance of the aurora in 1707 and 1716, followed a relative scarcity of great auroras during the Maunder minimum, a period of prolonged reduced <span class="hlt">solar</span> <span class="hlt">activity</span> from about 1645-1715. Observations in the early eighteenth century led to questions about the geographical extent, nature, and temporal variability of the auroras. Typically, such observations were included as part of recorded meteorological notations, though occasionally early astronomers, such as Tycho Brahe in the 1590s, included auroras in their observations. Meteorological observations were important because of the effects of weather and climate on agriculture, and, according to the belief at the time, on disease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35.2535S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35.2535S"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> and climate during the last millennium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Solanki, S. K.; Usoskin, I.; Schüssler, M.</p> <p></p> <p>The sunspot number is the longest running direct index of <span class="hlt">solar</span> <span class="hlt">activity</span>, with direct measurements starting in 1610. For many purposes, e.g., for comparisons with climate indices, it is still too short. We present a reconstruction of the cycle-averaged sunspot number over the last millennium based on 10Be concentrations in Greenland and Antarctic ice cores. As intermediate steps of the method, we also reconstruct the cosmic ray flux at Earth and the Sun's open magnetic flux. The reconstructions are validated by comparison with direct measurements or independent reconstructions. We also compare with records of global climate, in particular with the global temperature ("hockey stick") curve of Mann et al (1998). A reasonable agreement is found for the entire millennium, excluding only the last decades, when the two curves start diverging from each other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2531S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2531S"><span id="translatedtitle">The effects of <span class="hlt">solar</span> <span class="hlt">activity</span> on the global <span class="hlt">solar</span> radiation measured at Khargha Oasis in the Western Dessert of Egypt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaltout, M.; Mohamed, A.</p> <p></p> <p>Khargha is an Oasis in the Western Desert of Egypt of coordinates lat. 25 o 27/ N, long. 30 o 32 / E, and elevation 77.8 meter over the sea level. It is one of the driest areas in the world, the global <span class="hlt">solar</span> radiation measured starting from January 1976 till now by station belong to the Egyptian Meteorological Authority. We used the data for the last 25 years of the 20"' Century on the daily bases, it is more than two <span class="hlt">solar</span> cycles. The annual mean of relative humidity for Khargha is 30, and the total rainfall in mms as annual mean is less than one. Where, the evaporation in mms per day as annual mean is about 16. The total sky cover in oktas as annual mean is 0.4 at the midnight, while it is one oktas at the noon as 2annual mean, and 0.7 oktas on the mean of the day. The annual mean is 6.5 Kwh/rn /day for global <span class="hlt">solar</span> radiation. Fourier analysis technique used to analysis the time series to show any reflection for the 11-year cycle of the <span class="hlt">solar</span> <span class="hlt">activity</span> on the measured global radiation in remote, clean, and dry desert area. The results indicate periodicity's similar to the <span class="hlt">solar</span> <span class="hlt">activity</span> periodicities, especially that of the eleven year cycle, in a good indication for the effect of <span class="hlt">solar</span> <span class="hlt">activity</span> on the climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995IJBm...39...59H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995IJBm...39...59H&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> cycle and the incidence of foetal chromosome abnormalities detected at prenatal diagnosis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halpern, Gabrielle J.; Stoupel, Eliahu G.; Barkai, Gad; Chaki, Rina; Legum, Cyril; Fejgin, Moshe D.; Shohat, Mordechai</p> <p>1995-06-01</p> <p>We studied 2001 foetuses during the period of minimal <span class="hlt">solar</span> <span class="hlt">activity</span> of <span class="hlt">solar</span> cycle 21 and 2265 foetuses during the period of maximal <span class="hlt">solar</span> <span class="hlt">activity</span> of <span class="hlt">solar</span> cycle 22, in all women aged 37 years and over who underwent free prenatal diagnosis in four hospitals in the greater Tel Aviv area. There were no significant differences in the total incidence of chromosomal abnormalities or of trisomy between the two periods (2.15% and 1.8% versus 2.34% and 2.12%, respectively). However, the trend of excessive incidence of chromosomal abnormalities in the period of maximal <span class="hlt">solar</span> <span class="hlt">activity</span> suggests that a prospective study in a large population would be required to rule out any possible effect of extreme <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SoPh..241...67S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SoPh..241...67S"><span id="translatedtitle">Multifractality as a Measure of Complexity in <span class="hlt">Solar</span> Flare <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sen, Asok K.</p> <p>2007-03-01</p> <p>In this paper we use the notion of multifractality to describe the complexity in H α flare <span class="hlt">activity</span> during the <span class="hlt">solar</span> cycles 21, 22, and 23. Both northern and southern hemisphere flare indices are analyzed. Multifractal behavior of the flare <span class="hlt">activity</span> is characterized by calculating the singularity spectrum of the daily flare index time series in terms of the Hölder exponent. The broadness of the singularity spectrum gives a measure of the degree of multifractality or complexity in the flare index data. The broader the spectrum, the richer and more complex is the structure with a higher degree of multifractality. Using this broadness measure, complexity in the flare index data is compared between the northern and southern hemispheres in each of the three cycles, and among the three cycles in each of the two hemispheres. Other parameters of the singularity spectrum can also provide information about the fractal properties of the flare index data. For instance, an asymmetry to the left or right in the singularity spectrum indicates a dominance of high or low fractal exponents, respectively, reflecting a relative abundance of large or small fluctuations in the total energy emitted by the flares. Our results reveal that in the even (22nd) cycle the singularity spectra are very similar for the northern and southern hemispheres, whereas in the odd cycles (21st and 23rd) they differ significantly. In particular, we find that in cycle 21, the northern hemisphere flare index data have higher complexity than its southern counterpart, with an opposite pattern prevailing in cycle 23. Furthermore, small-scale fluctuations in the flare index time series are predominant in the northern hemisphere in the 21st cycle and are predominant in the southern hemisphere in the 23rd cycle. Based on these findings one might suggest that, from cycle to cycle, there exists a smooth switching between the northern and southern hemispheres in the multifractality of the flaring process. This new</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SoPh..271..183V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SoPh..271..183V"><span id="translatedtitle">Evolution of <span class="hlt">Solar</span> and Geomagnetic <span class="hlt">Activity</span> Indices, and Their Relationship: 1960 - 2001</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verbanac, G.; Mandea, M.; Vršnak, B.; Sentic, S.</p> <p>2011-07-01</p> <p>We employ annually averaged <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span> indices for the period 1960 - 2001 to analyze the relationship between different measures of <span class="hlt">solar</span> <span class="hlt">activity</span> as well as the relationship between <span class="hlt">solar</span> <span class="hlt">activity</span> and various aspects of geomagnetic <span class="hlt">activity</span>. In particular, to quantify the <span class="hlt">solar</span> <span class="hlt">activity</span> we use the sunspot number R s, group sunspot number R g, cumulative sunspot area Cum, <span class="hlt">solar</span> radio flux F10.7, and interplanetary magnetic field strength IMF. For the geomagnetic <span class="hlt">activity</span> we employ global indices Ap, Dst and Dcx, as well as the regional geomagnetic index RES, specifically estimated for the European region. In the paper we present the relative evolution of these indices and quantify the correlations between them. Variations have been found in: i) time lag between the <span class="hlt">solar</span> and geomagnetic indices; ii) relative amplitude of the geomagnetic and <span class="hlt">solar</span> <span class="hlt">activity</span> peaks; iii) dual-peak distribution in some of <span class="hlt">solar</span> and geomagnetic indices. The behavior of geomagnetic indices is correlated the best with IMF variations. Interestingly, among geomagnetic indices, RES shows the highest degree of correlation with <span class="hlt">solar</span> indices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7099180','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7099180"><span id="translatedtitle"><span class="hlt">Active</span> space heating and hot water supply with <span class="hlt">solar</span> energy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karaki, S.; Loef, G. O.G.</p> <p>1981-04-01</p> <p>Technical and economic assessments are given of <span class="hlt">solar</span> water heaters, both circulating, and of air-based and liquid-based <span class="hlt">solar</span> space heating systems. Both new and retrofit systems are considered. The technical status of flat-plate and evacuated tube collectors and of thermal storage is also covered. Non-technical factors are also briefly discussed, including the participants in the use of <span class="hlt">solar</span> heat, incentives and deterrents. Policy implications are considered as regards acceleration of <span class="hlt">solar</span> use, goals for <span class="hlt">solar</span> use, means for achieving goals, and interaction of governments, suppliers, and users. Government actions are recommended. (LEW)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988IEDL....9..368D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988IEDL....9..368D"><span id="translatedtitle"><span class="hlt">Influence</span> of perimeter recombination on high-efficiency GaAs p/n heteroface <span class="hlt">solar</span> cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demoulin, Paul D.; Melloch, Michael R.; Lundstrom, Mark S.; Carpenter, M. S.; Tobin, Stephen P.</p> <p>1988-08-01</p> <p>Perimeter recombination currents have been characterized for 0.5-cm-square and 2-cm-square p/n GaAs <span class="hlt">solar</span> cells. Measurements show that perimeter recombination dominates the n = 2 dark current component of these high-efficiency <span class="hlt">solar</span> cells. The results also suggest that perimeter recombination will be substantial even in much-larger-area <span class="hlt">solar</span> cells. Although little <span class="hlt">influence</span> on open-circuit voltage is expected, perimeter recombination may adversely affect the cell's one-sun fill factor. Because of its importance to one-sun applications, recombination at the junction perimeter must be suppressed before GaAs <span class="hlt">solar</span> cells approach their limiting conversion efficiencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35..284M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35..284M"><span id="translatedtitle">Minimum extreme temperature in the gulf of mexico: is there a connection with <span class="hlt">solar</span> <span class="hlt">activity</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maravilla, D.; Mendoza, B.; Jauregui, E.</p> <p></p> <p>Minimum extreme temperature ( MET) series from several meteorological stations of the Gulf of Mexico are spectrally analyzed using the Maximum Entrophy Method. We obtained periodicities similar to those found in the sunspot number, the magnetic <span class="hlt">solar</span> cycle, comic ray fluxes and geomagnetic <span class="hlt">activity</span> which are modulated by <span class="hlt">solar</span> <span class="hlt">activity</span>. We suggested that the <span class="hlt">solar</span> signal is perhaps present in the MET record of this region of Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4283619','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4283619"><span id="translatedtitle">Environmental <span class="hlt">influences</span> on children's physical <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pouliou, Theodora; Sera, Francesco; Griffiths, Lucy; Joshi, Heather; Geraci, Marco; Cortina-Borja, Mario; Law, Catherine</p> <p>2015-01-01</p> <p>Background This paper aims to assess whether 7-year-olds’ physical <span class="hlt">activity</span> is associated with family and area-level measures of the physical and socioeconomic environments. Methods We analysed the association of environments with physical <span class="hlt">activity</span> in 6497 singleton children from the UK Millennium Cohort Study with reliable accelerometer data (≥2 days and ≥10 h/day). <span class="hlt">Activity</span> levels were assessed as counts per minute; minutes of moderate to vigorous <span class="hlt">activity</span> (MVPA); and whether meeting recommended guidelines (≥60 min/day MVPA). Results Higher levels of children's physical <span class="hlt">activity</span> were associated with households without use of a car and with having a television in a child's bedroom (for counts per minute only). Aspects of the home socioeconomic environment that were associated with more children's physical <span class="hlt">activity</span> were lone motherhood, lower maternal socioeconomic position and education, family income below 60% national median, and not owning the home. Children's <span class="hlt">activity</span> levels were higher when parents perceived their neighbourhood as poor for bringing up children and also when families were living in the most deprived areas. Relationships were independent of characteristics such as child's body mass index and ethnic group. When adjusted for physical and socioeconomic correlates, the factors remaining significant in all outcomes were: household car usage and maternal education. Conclusions Although physical and socioeconomic environments are associated with children’s physical <span class="hlt">activity</span>, much of the variation appears to be determined by the child's home socioeconomic circumstances rather than the wider environment where they live. PMID:25359920</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013OAP....26..294P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013OAP....26..294P&link_type=ABSTRACT"><span id="translatedtitle">Endothelial Dysfunction and Blood Viscosity Inpatients with Unstable Angina in Different Periods of a <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parshina, S. S.; Tokaeva, L. K.; Dolgova, E. M.; Afanas'yeva, T. N.; Strelnikova, O. A.</p> <p></p> <p>The origin of hemorheologic and endothelial defects in patients with unstable angina (comparing with healthy persons) is determined by a <span class="hlt">solar</span> <span class="hlt">activity</span> period: the blood viscosity increases in a period of high <span class="hlt">solar</span> <span class="hlt">activity</span> in the vessels of small, medium and macro diameters, a local decompensate dysfunction of small vessels endothelium had been fixed (microcirculation area). In the period of a low <span class="hlt">solar</span> <span class="hlt">activity</span> there is an increase of a blood viscosity in vessels of all diameters, generalized subcompensated endothelial dysfunction is developed (on the background of the III phase blood clotting <span class="hlt">activating</span>). In the period of a high <span class="hlt">solar</span> <span class="hlt">activity</span> a higher blood viscosity had been fixed, comparing with the period of a low <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPD....47.0716J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPD....47.0716J"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Activity</span> in Cycle 24 - What do Acoustic Oscillations tell us?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, Kiran; Tripathy, Sushant; Simoniello, Rosaria; Hill, Frank</p> <p>2016-05-01</p> <p><span class="hlt">Solar</span> Cycle 24 is the weakest cycle in modern era of space- and ground-based observations. The number of sunspots visible on <span class="hlt">solar</span> disk and other measures of magnetic <span class="hlt">activity</span> have significantly decreased from the last cycle. It was also preceeded by an extended phase of low <span class="hlt">activity</span>, a period that raised questions on our understanding of the <span class="hlt">solar</span> <span class="hlt">activity</span> cycle and its origin. This unusual behavior was not only limited to the visible features in Sun's atmosphere, the helioseismic observations also revealed peculiar behavior in the interior. It was suggested that the changes in magnetic <span class="hlt">activity</span> were confined to shallower layers only, as a result low-degree mode frequencies were found to be anti-correlated with <span class="hlt">solar</span> <span class="hlt">activity</span>. Here we present results on the progression of Cycle 24 by analyzing the uninterrupted helioseismic data from GONG and SDO/HMI, and discuss differences and similarity between cycles 23 and 24 in relation to the <span class="hlt">solar</span> <span class="hlt">activity</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMSH21A0326R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMSH21A0326R"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">Activity</span> in the Green Corona Over Cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rušin, V.</p> <p>2006-12-01</p> <p>The intensity of the green coronal line (5303Å, Fe {\\sc xiv), which is directly proportional to the electron density as well as the temperature of the corona, is a good and sensitive indicator of the reflection of the photospheric <span class="hlt">activity</span> in the emission corona, mapping also the evolution of the magnetic fields in the <span class="hlt">active</span> regions on the <span class="hlt">solar</span> surface. In cycle 23 (1996 -2007), the average intensity of the green corona was of about 30% less when compared with that of the preceding cycle; this, however, does not necessarily imply a lower temperature of the corona, but rather a smaller number of <span class="hlt">active</span> regions and/or smaller strength of local magnetic fields in the latter. The maximum of the intensity of the green corona was observed in August 2001, preceding for about one and a half year that of sunspot number. Moreover, the increased intensities were not observed continuously in time and heliographic latitude, but rather in particular latitudes, with a slight time-lag between the north and south hemispheres. It is well known that a time-latitudinal distribution of the intensity of the green corona features two kinds of large-scale motions. The first is the so-called polar branch, which separates from the "main flow" in the middle latitudes in the cycle minimum, lasts for about 3 -4 years and disappears at the time of the maxima of <span class="hlt">solar</span> <span class="hlt">activity</span> near the poles. The other is the equatorial (or principal) branch, which after separation in middle-latitudes moves first towards the poles, then roughly 2 years after the polar branch reached the poles makes a U-turn at upper heliographic latitudes of ±70 degrees, and migrates towards the equator where it disappears in the next minimum; the life-time of this branch is about 18 years. Given the time of the splitting of the two branches, we can guess the time of the maximum and minimum of the forthcoming cycle - cycle 24: the corresponding numbers are 2011 and 2012.5 for the time of the "double" maximum and 2019 for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoSyR..50...44R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoSyR..50...44R"><span id="translatedtitle">The effect of <span class="hlt">solar</span> <span class="hlt">activity</span> on the evolution of <span class="hlt">solar</span> wind parameters during the rise of the 24th cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rod'kin, D. G.; Shugay, Yu. S.; Slemzin, V. A.; Veselovskii, I. S.</p> <p>2016-01-01</p> <p>The dynamics of parameters of the near-Earth <span class="hlt">solar</span> wind (SW) and the effect of <span class="hlt">solar</span> <span class="hlt">activity</span> on the parameters of three SW components (fast SW from large-scale coronal holes (CHs); slow SW from <span class="hlt">active</span> regions, streamers, and other sources; and transient flows related to sporadic <span class="hlt">solar</span> <span class="hlt">activity</span>) at the beginning of the 24th <span class="hlt">solar</span> cycle (2009-2011) are analyzed. It is demonstrated that temperaturedependent parameters of ionic composition (C+6/C+5 and O+7/O+6) of the transient SW component in the profound minimum of <span class="hlt">solar</span> <span class="hlt">activity</span> in 2009 were correlated with the variation of the rate of weak (type C and weaker) flares. This verifies the presence of a hot component associated with these flares in the SW. The variations in the velocity and the kinetic temperature of fast SW from CHs with an increase in <span class="hlt">activity</span> are more pronounced in the bulk of the high-speed stream, and the variations of O+7/O+6 and Fe/O ratios and the magnitude of the interplanetary magnetic field are the most prominent in the region of interaction between fast and slow SW streams. The analysis reveals that a value of O+7/O+6 = 0.1 serves as the criterion to distinguish between fast SW streams and interplanetary coronal mass ejections in the 2009 <span class="hlt">activity</span> minimum. This value is lower than the one (0.145) determined earlier based on the data on the 23rd cycle (Zhao et al., 2009). Therefore, the distinguishing criterion is not an absolute one and depends on the <span class="hlt">solar</span> <span class="hlt">activity</span> level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020087931','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020087931"><span id="translatedtitle">Sources of Geomagnetic <span class="hlt">Activity</span> during Nearly Three <span class="hlt">Solar</span> Cycles (1972-2000)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.; Cliver, E. W.; White, Nicholas E. (Technical Monitor)</p> <p>2002-01-01</p> <p>We examine the contributions of the principal <span class="hlt">solar</span> wind components (corotating highspeed streams, slow <span class="hlt">solar</span> wind, and transient structures, i.e., interplanetary coronal mass ejections (CMEs), shocks, and postshock flows) to averages of the aa geomagnetic index and the interplanetary magnetic field (IMF) strength in 1972-2000 during nearly three <span class="hlt">solar</span> cycles. A prime motivation is to understand the <span class="hlt">influence</span> of <span class="hlt">solar</span> cycle variations in <span class="hlt">solar</span> wind structure on long-term (e.g., approximately annual) averages of these parameters. We show that high-speed streams account for approximately two-thirds of long-term aa averages at <span class="hlt">solar</span> minimum, while at <span class="hlt">solar</span> maximum, structures associated with transients make the largest contribution (approx. 50%), though contributions from streams and slow <span class="hlt">solar</span> wind continue to be present. Similarly, high-speed streams are the principal contributor (approx. 55%) to <span class="hlt">solar</span> minimum averages of the IMF, while transient-related structures are the leading contributor (approx. 40%) at <span class="hlt">solar</span> maximum. These differences between <span class="hlt">solar</span> maximum and minimum reflect the changing structure of the near-ecliptic <span class="hlt">solar</span> wind during the <span class="hlt">solar</span> cycle. For minimum periods, the Earth is embedded in high-speed streams approx. 55% of the time versus approx. 35% for slow <span class="hlt">solar</span> wind and approx. 10% for CME-associated structures, while at <span class="hlt">solar</span> maximum, typical percentages are as follows: high-speed streams approx. 35%, slow <span class="hlt">solar</span> wind approx. 30%, and CME-associated approx. 35%. These compositions show little cycle-to-cycle variation, at least for the interval considered in this paper. Despite the change in the occurrences of different types of <span class="hlt">solar</span> wind over the <span class="hlt">solar</span> cycle (and less significant changes from cycle to cycle), overall, variations in the averages of the aa index and IMF closely follow those in corotating streams. Considering <span class="hlt">solar</span> cycle averages, we show that high-speed streams account for approx. 44%, approx. 48%, and approx. 40% of the <span class="hlt">solar</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.1421S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.1421S"><span id="translatedtitle">Cyclicity of forest fire occurrence at Kola Peninsula (North-Western Russia) in connection to meteorological and <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shumilov, O. I.; Kasatkina, E. A.; Knyazev, N. V.; Lukina, N. V.</p> <p>2010-05-01</p> <p>The cyclicity of forest fire number for the period 1958-2007 at Kola Peninsula was investigated. We used the data of regular aerial surveying. The frequency of forest fires was compared with regional meteorological and dendrochronological records. Spectral analysis with help of MEM and wavelet revealed a clear cyclic character of fire occurrence with two main maxima. The main one occurred at frequencies around 18-20 years and the other in the band 2.8-4 year. Detailed analysis showed that fire occurrence at Kola Peninsula was a result of a complicated mixture of both anthropogenic and climatic forcings (temperature and precipitation). Climatic forcing is <span class="hlt">influenced</span> by variations of <span class="hlt">solar</span> <span class="hlt">activity</span> (<span class="hlt">solar</span> radiation, cosmic rays, cosmic dust etc.). Two maxima in the fire occurrence spectrum seem to be connected to one of the main cycles of <span class="hlt">solar</span> <span class="hlt">activity</span> (22 y) and NAO oscillation (3-4 y). As it is well known the NAO variations are rather tightly connected to cyclonic <span class="hlt">activity</span> in the North Atlantic region. The enhanced numbers of fires were observed close to minima of <span class="hlt">solar</span> <span class="hlt">activity</span>. These results may be applied for fire forecasting at Kola Peninsula. This work is financially supported by the Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPhD...42d5109T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPhD...42d5109T"><span id="translatedtitle"><span class="hlt">Influence</span> of capacitance characteristic on dye-sensitized <span class="hlt">solar</span> cell's IPCE measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Hanmin; Liu, Lifei; Liu, Bin; Kui Yuan, Shi; Wang, Xiangyan; Wang, Ying; Yu, Tao; Zou, Zhigang</p> <p>2009-02-01</p> <p>It is found that the traditional monochromatic incident photon-to-electron conversion efficiency (IPCE) measurement method, such as the American Society for Testing and Materials standard (ASTM), is not suitable for measuring the IPCE of dye-sensitized <span class="hlt">solar</span> cells (DSSCs). Experiments showed that the chopper's frequency in this method <span class="hlt">influences</span> the measured DSSCs' IPCE value considerably, while no such impact was found in that of the Si cell. The quantitative analysis, which is based on equivalent circuits and parameter estimation, proved the existence of capacitance characteristics in DSSCs causing the fluctuation of the measured IPCE. An equivalent circuit parameter was estimated from a typical dye <span class="hlt">solar</span> cell, which was characterized with the crystalline ingredient, the particle size and the I-V curve. The fluctuations of the measured IPCE were revealed by adjusting the chopper frequencies of one traditional IPCE measurement system. Finally, the method to obtain the real value of DSSCs' IPCE is proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257019S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257019S"><span id="translatedtitle"><span class="hlt">Solar</span>-stellar connection : A <span class="hlt">solar</span> analogous behaviour by an <span class="hlt">active</span> ultra fast rotator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sairam, Lalitha; Schmitt, Juergen; Pal Singh, Kulinder</p> <p>2015-08-01</p> <p>AB Dor is an ultra-fast rotating (Prot ~ 0.51 d) <span class="hlt">active</span> young K dwarf with an age of ~40-50 Myr. Located as a foreground star towards large magellanic cloud (LMC), AB Dor has the advantage of being observed at all times by most of the X-ray satellites making it a favourite calibration target. AB Dor has been repeatedly observed for calibration by reflection grating spectrometer (RGS) on board XMM- Newton over last decade. This gives an ideal opportunity to perform a detailed analysis of the coronal emission, and to compare the flare characteristics with the Sun, since the Sun is usually considered as a prototype of low mass stars. Flares are frequent in low mass <span class="hlt">active</span> stars across the electromagnetic spectrum similar to the Sun. We will for the first time, present an analysis of 30 intense X-ray flares observed from AB Dor. These flares detected in XMM-Newton data show a rapid rise (500-3000 s) and a slow decay (1000-6000 s). The derived X-ray luminosity during the flares ranges between 30.20 ≤ log(Lx) ≤ 30.83 erg/s; the flare peak temperature lies between 30-80 MK and the emission measures for these flares are in the range of 52.3 ≤ log(EM) ≤ 53.5 cm^-3. Our studies suggest that the scaling law between the flare peak emission measure and the flare peak temperature for all the flares observed on AB Dor is very similar to the relationship followed by <span class="hlt">solar</span> flares, despite the fact that the AB Dor flare emission is ~250 times higher than the <span class="hlt">solar</span> flare emission. We also carried out a homogenous study of flare frequencies, energetics and its occurrence in AB Dor. The frequency distribution of flare energies is a crucial diagnostic to calculate the overall energy residing in a flare. Our results of this study indicate that the large flare (33 ≤ log(E) ≤ 34 erg) may not contribute to the heating of the corona. We will show the presence of a possible long-term cycle in AB Dor both from a photospheric and coronal point of view, similar to the 11-year</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........14C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........14C"><span id="translatedtitle">A study of <span class="hlt">solar</span> magnetic fields below the surface, at the surface, and in the <span class="hlt">solar</span> atmosphere - understanding the cause of major <span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chintzoglou, Georgios</p> <p></p> <p>Magnetic fields govern all aspects of <span class="hlt">solar</span> <span class="hlt">activity</span> from the 11-year <span class="hlt">solar</span> cycle to the most energetic events in the <span class="hlt">solar</span> system, such as <span class="hlt">solar</span> flares and Coronal Mass Ejections (CMEs). As seen on the surface of the sun, this <span class="hlt">activity</span> emanates from localized concentrations of magnetic fields emerging sporadically from the <span class="hlt">solar</span> interior. These locations are called <span class="hlt">solar</span> <span class="hlt">Active</span> Regions (ARs). However, the fundamental processes regarding the origin, emergence and evolution of <span class="hlt">solar</span> magnetic fields as well as the generation of <span class="hlt">solar</span> <span class="hlt">activity</span> are largely unknown or remain controversial. In this dissertation, multiple important issues regarding <span class="hlt">solar</span> magnetism and <span class="hlt">activities</span> are addressed, based on advanced observations obtained by AIA and HMI instruments aboard the SDO spacecraft. First, this work investigates the formation of coronal magnetic flux ropes (MFRs), structures associated with major <span class="hlt">solar</span> <span class="hlt">activity</span> such as CMEs. In the past, several theories have been proposed to explain the cause of this major <span class="hlt">activity</span>, which can be categorized in two contrasting groups (a) the MFR is formed in the eruption, and (b) the MFR pre-exists the eruption. This remains a topic of heated debate in modern <span class="hlt">solar</span> physics. This dissertation provides a complete treatment of the role of MFRs from their genesis all the way to their eruption and even destruction. The study has uncovered the pre-existence of two weakly twisted MFRs, which formed during confined flaring 12 hours before their associated CMEs. Thus, it provides unambiguous evidence for MFRs truly existing before the CME eruptions, resolving the pre-existing MFR controversy. Second, this dissertation addresses the 3-D magnetic structure of complex emerging ARs. In ARs the photospheric fields might show all aspects of complexity, from simple bipolar regions to extremely complex multi-polar surface magnetic distributions. In this thesis, we introduce a novel technique to infer the subphotospheric configuration of emerging</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5686767','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5686767"><span id="translatedtitle"><span class="hlt">Solar</span> Energy Education. Humanities: <span class="hlt">activities</span> and teacher's guide. Field test edition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1982-01-01</p> <p><span class="hlt">Activities</span> are outlined to introduce students to information on <span class="hlt">solar</span> energy while performing ordinary classroom work. In this teaching manual <span class="hlt">solar</span> energy is integrated with the humanities. The <span class="hlt">activities</span> include such things as stories, newspapers, writing assignments, and art and musical presentations all filled with energy related terms. An energy glossary is provided. (BCS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1111N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1111N"><span id="translatedtitle">Lyman-alpha line as a <span class="hlt">solar</span> <span class="hlt">activity</span> index for calculations of <span class="hlt">solar</span> spectrum in the EUV region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nusinov, Anatoliy; Kazachevskaya, Tamara; Katyushina, Valeria; Woods, Thomas</p> <p></p> <p>It is investigated a possibility of retrieval of <span class="hlt">solar</span> spectrum data using intensity observational data of the only <span class="hlt">solar</span> spectral line L (Hydrogen Lyman-alpha, 121.6 nm).Using as an example spectra obtained by SEE instruments on TIMED satellite, it was shown, that both for lines and for continuum in the spectral range 27-105 nm, which is essential for ionization processes in the ionosphere, a correlation between their intensities and L was high. Therefore it becomes possible to use L measurements data as a natural <span class="hlt">solar</span> <span class="hlt">activity</span> index for calculations of EUV <span class="hlt">solar</span> emission spectrum for solving aeronomical problems. It is noticed, that EUV model, obtained with using SEE data, does not allow to calculate correctly critical frequencies of ionospheric E-layer owing to low intensities of lines 97.7 and 102.6 nm, which produce the main part of ionization in ionospheric E-region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...827..140R&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...827..140R&link_type=ABSTRACT"><span id="translatedtitle">Statistical Analysis of Acoustic Wave Parameters Near <span class="hlt">Solar</span> <span class="hlt">Active</span> Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rabello-Soares, M. Cristina; Bogart, Richard S.; Scherrer, Philip H.</p> <p>2016-08-01</p> <p>In order to quantify the <span class="hlt">influence</span> of magnetic fields on acoustic mode parameters and flows in and around <span class="hlt">active</span> regions, we analyze the differences in the parameters in magnetically quiet regions nearby an <span class="hlt">active</span> region (which we call “nearby regions”), compared with those of quiet regions at the same disk locations for which there are no neighboring <span class="hlt">active</span> regions. We also compare the mode parameters in <span class="hlt">active</span> regions with those in comparably located quiet regions. Our analysis is based on ring-diagram analysis of all <span class="hlt">active</span> regions observed by the Helioseismic and Magnetic Imager (HMI) during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the <span class="hlt">active</span> regions, for which it is about 5.1 mHz. This amplitude enhacement (the “acoustic halo effect”) is as large as that observed in the <span class="hlt">active</span> regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes from a deficit to an excess at around 4.2 mHz, but averages to zero over all modes. The frequency difference in nearby regions increases with increasing frequency until a point at which the frequency shifts turn over sharply, as in <span class="hlt">active</span> regions. However, this turnover occurs around 4.9 mHz, which is significantly below the acoustic cutoff frequency. Inverting the horizontal flow parameters in the direction of the neigboring <span class="hlt">active</span> regions, we find flows that are consistent with a model of the thermal energy flow being blocked directly below the <span class="hlt">active</span> region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...754L..40T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...754L..40T"><span id="translatedtitle">Spectroscopic Observations of Fe XVIII in <span class="hlt">Solar</span> <span class="hlt">Active</span> Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teriaca, Luca; Warren, Harry P.; Curdt, Werner</p> <p>2012-08-01</p> <p>The large uncertainties associated with measuring the amount of high temperature emission in <span class="hlt">solar</span> <span class="hlt">active</span> regions (ARs) represents a significant impediment to making progress on the coronal heating problem. Most current observations at temperatures of 3 MK and above are taken with broadband soft X-ray instruments. Such measurements have proven difficult to interpret unambiguously. Here, we present the first spectroscopic observations of the Fe XVIII 974.86 Å emission line in an on-disk AR taken with the SUMER instrument on SOHO. Fe XVIII has a peak formation temperature of 7.1 MK and provides important constraints on the amount of impulsive heating in the corona. Detailed evaluation of the spectra and comparison of the SUMER data with soft X-ray images from the X-Ray Telescope on Hinode confirm that this line is unblended. We also compare the spectroscopic data with observations from the Atmospheric Imaging Assembly (AIA) 94 Å channel on the <span class="hlt">Solar</span> Dynamics Observatory. The AIA 94 Å channel also contains Fe XVIII, but is blended with emission formed at lower temperatures. We find that it is possible to remove the contaminating blends and form relatively pure Fe XVIII images that are consistent with the spectroscopic observations from SUMER. The observed spectra also contain the Ca XIV 943.63 Å line that, although a factor 2-6 weaker than the Fe XVIII 974.86 Å line, allows us to probe the plasma around 3.5 MK. The observed ratio between the two lines indicates (isothermal approximation) that most of the plasma in the brighter Fe XVIII AR loops is at temperatures between 3.5 and 4 MK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH53B2497Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH53B2497Y"><span id="translatedtitle"><span class="hlt">Influence</span> of the <span class="hlt">Solar</span> Wind Speed on the Propagation of Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yashiro, S.; Tokumaru, M.; Fujiki, K.; Iju, T.; Akiyama, S.; Makela, P. A.; Gopalswamy, N.</p> <p>2015-12-01</p> <p>We investigate the <span class="hlt">influence</span> of the <span class="hlt">solar</span> wind (SW) on the propagation of a set of 191 coronal mass ejections (CMEs) near the Sun during the period 1996-2013. The CMEs were observed by LASCO on board SOHO and their source regions were identified using the CME-associated eruptive features (flares, filament eruptions, dimmings) in X-ray, EUV, microwave, and Hα observations. The SW speeds above the CME source regions were estimated from the interplanetary scintillation (IPS) observations from the <span class="hlt">Solar</span> Terrestrial Environ Laboratory, Nagoya University. We considered only CMEs from close to the limb in order to avoid the projection effects. We also considered CMEs with at least 10 height-time measurements in order to avoid the large uncertainty in the acceleration measurements. We confirm the well-known CME-SW relationship that the CMEs propagating faster (slower) than the ambient <span class="hlt">solar</span> wind are likely to decelerate (accelerate). The correlation between the acceleration and the difference of the CME and the SW speeds is high with a correlation coefficient of -0.74, slightly lower compared to the one for CMEs associated with interplanetary radio bursts (Gopalswamy et al. 2001, JGR, 106, 29219). There are many accelerating CMEs in our sample with a speed similar to the ambient <span class="hlt">solar</span> wind speed. This could be due to selection effect because accelerating CMEs tend to remain visible longer than decelerating ones. We also found that CMEs originating from around the sources of the fast <span class="hlt">solar</span> wind tend to be faster, indicating that the open magnetic fields above the CME source regions affect the CME propagation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1819Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1819Z"><span id="translatedtitle">Helicity from observational <span class="hlt">solar</span> magnetic fields and the relationship with <span class="hlt">solar</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Hongqi</p> <p></p> <p>The helicity is important to present the basic topological configuration of magnetic field trans-ferred form the <span class="hlt">solar</span> subatmosphere into the interplanetary space. In this talk, the basic configuration of magnetic field and helicity in the <span class="hlt">solar</span> atmosphere have been discussed in the following: 1) The Hinode high resolution vector magnetograms provide the important infor-mation on the fine features of current helicity density and the possible accumulated process of magnetic helicity in the <span class="hlt">solar</span> atmosphere. 2) The relationship between the eruption of <span class="hlt">solar</span> flare-CMEs and helicity transfer from the suntamosphere has be presented based on the analy-sis of photospheric vector magnetograms. 3) The statistical distribution of magnetic field (and helicity) in <span class="hlt">solar</span> atmosphere and its reversals with <span class="hlt">solar</span> cycles are presented by means of the observational (vector) magnetograms. As the magnetic fields in the <span class="hlt">solar</span> surface provides the information on the formation of magnetic field in the <span class="hlt">solar</span> convection zone, the statistical anal-ysis of the observational magnetic helicity is important for the confirmation of the alpha-effect of the <span class="hlt">solar</span> dynamo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=hand&pg=3&id=EJ910667','ERIC'); return false;" href="http://eric.ed.gov/?q=hand&pg=3&id=EJ910667"><span id="translatedtitle">Hands-On <span class="hlt">Activities</span> and Their <span class="hlt">Influence</span> on Students' Interest</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Holstermann, Nina; Grube, Dietmar; Bogeholz, Susanne</p> <p>2010-01-01</p> <p>This study investigates the <span class="hlt">influence</span> of hands-on <span class="hlt">activities</span> on students' interest. We researched whether students with experience in specific hands-on <span class="hlt">activities</span> show higher interest in these <span class="hlt">activities</span> than students without experience. Furthermore, the relationship between the quality of the hands-on experience and interest in the respective…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sofit&id=EJ826775','ERIC'); return false;" href="http://eric.ed.gov/?q=sofit&id=EJ826775"><span id="translatedtitle">Physical <span class="hlt">Activity</span> and Environmental <span class="hlt">Influences</span> during Secondary School Physical Education</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chow, Bik C.; McKenzie, Thomas L.; Louie, Lobo</p> <p>2009-01-01</p> <p>Physical <span class="hlt">activity</span> engagement during physical education is important for many reasons, including developing physical fitness and movement skills and promoting health. Much more is known about physical <span class="hlt">activity</span> in elementary than secondary schools. We examined physical <span class="hlt">activity</span> and how it was <span class="hlt">influenced</span> by instructor-related and environmental…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010A%26A...519A..44V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010A%26A...519A..44V"><span id="translatedtitle">Testing magnetofrictional extrapolation with the Titov-Démoulin model of <span class="hlt">solar</span> <span class="hlt">active</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valori, G.; Kliem, B.; Török, T.; Titov, V. S.</p> <p>2010-09-01</p> <p>We examine the nonlinear magnetofrictional extrapolation scheme using the <span class="hlt">solar</span> <span class="hlt">active</span> region model by Titov and Démoulin as test field. This model consists of an arched, line-tied current channel held in force-free equilibrium by the potential field of a bipolar flux distribution in the bottom boundary. A modified version with a parabolic current density profile is employed here. We find that the equilibrium is reconstructed with very high accuracy in a representative range of parameter space, using only the vector field in the bottom boundary as input. Structural features formed in the interface between the flux rope and the surrounding arcade - “hyperbolic flux tube” and “bald patch separatrix surface” - are reliably reproduced, as are the flux rope twist and the energy and helicity of the configuration. This demonstrates that force-free fields containing these basic structural elements of <span class="hlt">solar</span> <span class="hlt">active</span> regions can be obtained by extrapolation. The <span class="hlt">influence</span> of the chosen initial condition on the accuracy of reconstruction is also addressed, confirming that the initial field that best matches the external potential field of the model quite naturally leads to the best reconstruction. Extrapolating the magnetogram of a Titov-Démoulin equilibrium in the unstable range of parameter space yields a sequence of two opposing evolutionary phases, which clearly indicate the unstable nature of the configuration: a partial buildup of the flux rope with rising free energy is followed by destruction of the rope, losing most of the free energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JSR....53..319V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JSR....53..319V"><span id="translatedtitle">Are <span class="hlt">solar</span> <span class="hlt">activity</span> and sperm whale Physeter macrocephalus strandings around the North Sea related?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vanselow, Klaus Heinrich; Ricklefs, Klaus</p> <p>2005-04-01</p> <p>In the final decades of the last century, an increasing number of strandings of male sperm whales ( Physeter macrocephalus) around the North Sea led to an increase in public interest. Anthropogenic <span class="hlt">influences</span> (such as contaminants or intensive sound disturbances) are supposed to be the main causes, but natural environmental effects may also explain the disorientation of the animals. We compared the documented sperm whale strandings in the period from 1712 to 2003 with <span class="hlt">solar</span> <span class="hlt">activity</span>, especially with sun spot number periodicity and found that 90% of 97 sperm whale stranding events around the North Sea took place when the smoothed sun spot period length was below the mean value of 11 years, while only 10% happened during periods of longer sun spot cycles. The relation becomes even more pronounced (94% to 6%, n = 70) if a smaller time window from November to March is used (which seems to be the main southward migration period of male sperm whales). Adequate chi-square tests of the data give a significance of 1% error probability that sperm whale strandings can depend on <span class="hlt">solar</span> <span class="hlt">activity</span>. As an alternative explanation, we suggest that variations of the earth's magnetic field, due to variable energy fluxes from the sun to the earth, may cause a temporary disorientation of migrating animals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26832247','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26832247"><span id="translatedtitle"><span class="hlt">Influence</span> of wavefront aberration on the imaging performance of the <span class="hlt">solar</span> grating spectrometer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, L H; Rao, C H; Gu, N T; Huang, L H; Qiu, Q</p> <p>2016-01-11</p> <p>The <span class="hlt">solar</span> grating spectrometer is an important tool to study the thermodynamic properties of the <span class="hlt">solar</span> atmosphere with different height distribution, but its imaging performance will be degraded by the wavefront aberration. On the other hand, narrow slit of the grating spectrometer will filter the wavefront aberration to a certain extent. In this paper, the mathematical relation between the wavefront aberration and the imaging performance of the grating spectrometer is derived. The numerical simulation is performed and is validated by the experiment. The results demonstrate that: The <span class="hlt">influence</span> of the wavefront aberration with the different types and magnitudes on the spectral resolution and the energy utilization is different. The <span class="hlt">influence</span> of the different slits on the wavefront aberrations is different. Generally, the smaller the slit is, the better the spectral resolution is. However, this is not true for the low-frequency dominated aberration, e.g. the defocus, since its low frequency will also be blocked by the narrow slit. If the <span class="hlt">influence</span> of the filter slit on the wavefront aberration cannot be taken into account, it will lead to adaptive optics over-compensation. PMID:26832247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015rasc.conf..166A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015rasc.conf..166A"><span id="translatedtitle">Detrimental Effects of Extreme <span class="hlt">Solar</span> <span class="hlt">Activity</span> on Life on Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Airapetian, Vladimir; Glocer, Alex; Jackman, Charles</p> <p>2015-07-01</p> <p><span class="hlt">Solar</span> Coronal Mass Ejections (CMEs), the most energetic eruptions in the <span class="hlt">Solar</span> System, represent large-scale disturbances forming with the <span class="hlt">solar</span> corona and are associated with <span class="hlt">solar</span> flares and <span class="hlt">Solar</span> Energetic Particles (SEP) events. Current Kepler data from <span class="hlt">solar</span>-like stars suggest that the frequency of occurrence of energetic flares and associated CMEs from the Sun can be as high as 1 per 1500 years. What effects would CME and associated SEPs have on Earth's habitability? We have performed a three-dimensional time-dependent global magnetohydrodynamic simulation of the magnetic interaction of such a CME cloud with the Earth's magnetosphere. We calculated the global structure of the perturbed magnetosphere and derive the latitude of the open-closed magnetic field boundary. We used a 2D GSFC atmospheric code to calculate the efficiency of ozone depletion in the Earth's atmosphere due to SEP events and its effects on our society and life on Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8234542','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8234542"><span id="translatedtitle"><span class="hlt">Influence</span> of vegetarianism on fibrinolytic <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ho, C H; Chwang, L C</p> <p>1993-01-01</p> <p>Blood glucose, cholesterol and triglyceride levels were determined and the venous occlusion test (VOT) was administered to 15 vegetarians (mean age 46.2 years, SD 15.1) and 20 non-vegetarians (mean age 38.3 years, SD 8.3). The tissue plasminogen <span class="hlt">activator</span> (tPA), plasminogen <span class="hlt">activator</span> inhibitor (PAI) and euglobulin lysis time (ELT) were measured before and after VOT. The means of all the parameters were not significantly different between vegetarians and non-vegetarians. TPA increased after VOT in both the vegetarians and the non-vegetarians, but the changing amplitudes of tPA, PAI and ELT induced by VOT were not significantly different in either group. This study evidenced no significant difference in the changes of fibrinolytic <span class="hlt">activity</span> between vegetarians and non-vegetarians. PMID:8234542</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...588A..38L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...588A..38L"><span id="translatedtitle"><span class="hlt">Activity</span> trends in young <span class="hlt">solar</span>-type stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lehtinen, J.; Jetsu, L.; Hackman, T.; Kajatkari, P.; Henry, G. W.</p> <p>2016-04-01</p> <p>Aims: We study a sample of 21 young and <span class="hlt">active</span> <span class="hlt">solar</span>-type stars with spectral types ranging from late F to mid K and characterize the behaviour of their <span class="hlt">activity</span>. Methods: We apply the continuous period search (CPS) time series analysis method on Johnson B- and V-band photometry of the sample stars, collected over a period of 16 to 27 years. Using the CPS method, we estimate the surface differential rotation and determine the existence and behaviour of <span class="hlt">active</span> longitudes and <span class="hlt">activity</span> cycles on the stars. We supplement the time series results by calculating new log R'HK = log F'HK/σTeff4 emission indices for the stars from high resolution spectroscopy. Results: The measurements of the photometric rotation period variations reveal a positive correlation between the relative differential rotation coefficient and the rotation period as k ∝ Prot1.36, but do not reveal any dependence of the differential rotation on the effective temperature of the stars. Secondary period searches reveal <span class="hlt">activity</span> cycles in 18 of the stars and temporary or persistent <span class="hlt">active</span> longitudes in 11 of them. The <span class="hlt">activity</span> cycles fall into specific <span class="hlt">activity</span> branches when examined in the log Prot/Pcyc vs. log Ro-1, where Ro-1 = 2Ωτc, or log Prot/Pcyc vs. log R'HK diagram. We find a new split into sub-branches within this diagram, indicating multiple simultaneously present cycle modes. <span class="hlt">Active</span> longitudes appear to be present only on the more <span class="hlt">active</span> stars. There is a sharp break at approximately log R'HK = -4.46 separating the less <span class="hlt">active</span> stars with long-term axisymmetric spot distributions from the more <span class="hlt">active</span> ones with non-axisymmetric configurations. In seven out of eleven of our stars with clearly detected long-term non-axisymmetric spot <span class="hlt">activity</span> the estimated <span class="hlt">active</span> longitude periods are significantly shorter than the mean photometric rotation periods. This systematic trend can be interpreted either as a sign of the <span class="hlt">active</span> longitudes being sustained from a deeper level in the stellar interior</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E.159A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014cosp...40E.159A&link_type=ABSTRACT"><span id="translatedtitle">Reaction of physiological factors on the <span class="hlt">solar</span>-geomagnetic <span class="hlt">activity</span> (the physical mechanisms)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Avakyan, Sergey; Voronin, Nikolai; Dubarenko, Konstantin</p> <p></p> <p>This presentation proposes and provides substantiation for a hypothesis concerning the mechanism by which <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span> (mainly of <span class="hlt">solar</span> flares and magnetic storms) affects the biosphere, including man. The hypothesis, including a physical mechanism introduced by the authors, is that high-lying (Rydberg) states of all gases of the earth’s upper atmosphere are excited by ionospheric energetic electrons. Rydberg atoms, molecules and ions of all atmospheric gases emit characteristic radio emission in the spectral range from decimeters to millimeters. This radiation can easily penetrate to low atmosphere and biosphere carrying complete information about power and duration of <span class="hlt">solar</span> flare and geomagnetic storms to biosphere. The microwave radioemission have the resonances at the spectral range 109 ÷ 1012 Hz at the cells and membranes, DNA and RNA, molecules of haemoglobin, erythrocytes, and this fact can explain the extremely small threshold for <span class="hlt">influence</span> of ionospheric radioemission at the monochromatic (characteristic) transitions on biological objects, including the viscosity of blood. The energy estimates of the flux intensity of microwave radiation of the ionosphere from Rydberg states are used to prove for the first time that the values of this flux agree with the experimental data. A method is proposed for distinguishing the contributions of microwave radiation and magnetic perturbation in the geo-biocorrelations, taking into account the effect that the magnetic-field variations are not in phase with the flux of corpuscles from the radiation belts in the ionosphere during the period of a geomagnetic storm. Quanta of microwave radiation are emitted from the heights of 90 - 360 km, i.e. in the basic ionosphere regions. Their energy by almost 10 orders of magnitude exceeds that of the quanta of low-frequency electromagnetic background of the ionosphere (with the frequencies lower than 100 Hz, which coincide with those of biorhythms). Thereby</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........24X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........24X"><span id="translatedtitle">Superthermal electrons at Mars: Photoelectrons, <span class="hlt">solar</span> wind electrons, and dust storm <span class="hlt">influences</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Shaosui</p> <p></p> <p>Mars is unique in the <span class="hlt">solar</span> system in terms of its interaction with <span class="hlt">solar</span> wind because it lacks of a significant intrinsic global magnetic field but possesses localized strong crustal fields. This interaction results in a very complex magnetic topology at Mars so that superthermal electrons, mainly including photoelectrons and <span class="hlt">solar</span> wind electrons, can be distinctively important for such a complicated planetary space environment. These energetic electrons (1-1000 electron volts) can carry and rapidly redistribute energy along the magnetic field lines. They are also a reliable tool to deduce the Martian magnetic topology, which is critical to understand the electromagnetic dynamics of the Martian space environment. The investigation methodology involves both data analysis and modeling. This dissertation mainly investigates three topics of superthermal electrons at Mars. (1) This dissertation confirms that the long-lived <span class="hlt">influence</span> of Martian low-altitude dust storms on high-altitude photoelectron fluxes is common for a wide range of energy and pitch angles and determines that this effect originates from the thermosphere-ionosphere source region of the photoelectrons, rather than at exospheric altitudes at or above MGS. Through simulations, the results suggest that the global dust storm altered the photoelectron fluxes by causing CO2 to be the dominant species at a much larger altitude range than usual. (2) Because the integral of the production rate above the superthermal electron exobase is about the same for all <span class="hlt">solar</span> zenith angles, quite counterintuitively, it is found, observationally and numerically/theoretically, that the high-altitude photoelectron fluxes are quite independent of <span class="hlt">solar</span> zenith angle. (3) Based on the energy spectral (flux against energy) difference between photoelectrons and <span class="hlt">solar</span> wind electrons, a statistical approach is taken to distinguish the two populations and also allows us to quantify the occurrence rate of <span class="hlt">solar</span> wind electron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPRS...67...13H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPRS...67...13H"><span id="translatedtitle"><span class="hlt">Influence</span> of <span class="hlt">solar</span> elevation in radiometric and geometric performance of multispectral photogrammetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Honkavaara, Eija; Markelin, Lauri; Rosnell, Tomi; Nurminen, Kimmo</p> <p>2012-01-01</p> <p><span class="hlt">Solar</span> elevation is an important factor in passive, airborne data collection. The minimum <span class="hlt">solar</span> elevation allowed in missions for topographic mapping is typically 30° from the horizon. A general hypothesis is that the new, high dynamic range, digital large-format photogrammetric sensors allow for high data quality, even with lower <span class="hlt">solar</span> elevations, which would improve the feasibility and cost-efficiency of photogrammetric technology in various applications. Objectives of this study were to investigate theoretically and empirically the impacts of <span class="hlt">solar</span> elevation in modern photogrammetric processes. Two cutting-edge aspects of novel photogrammetric technology were considered: point cloud creation by automatic image matching and reflectance calibration of image data. For the empirical study, we used image data collected by a large-format photogrammetric camera, Intergraph DMC, with low (25-28°) and medium (44-48°) <span class="hlt">solar</span> elevations from 2, 3 and 4 km heights. We did not detect negative <span class="hlt">influences</span> of decreasing <span class="hlt">solar</span> elevation during our general evaluations: an analysis of image histograms showed that the ranges of digital numbers could be tuned to similar levels with exposure settings, and evaluations of density and the accuracy of point clouds did not show any reduction of quality. We carried out detailed evaluations in forests, roads and fields. Our results did not indicate deterioration of the quality in sun-illuminated areas with decreasing <span class="hlt">solar</span> elevation. In shadowed areas, we observed that the variation of image signal was reduced in comparison to sun-illuminated areas and emphasized the issue of complication of reflectance calibration. Artefacts appeared in automatically generated point clouds in areas shadowed by trees, which we observed in flat objects as up to 3 times increased random height variation and decreased success in measuring the terrain surface. Our results also showed that the overall performance of point cloud generation was high. Typically</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CEAB...36....9G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CEAB...36....9G"><span id="translatedtitle">Distribution of <span class="hlt">activity</span> at the <span class="hlt">solar</span> <span class="hlt">active</span> longitudes between 1979 - 2011 in the northern hemisphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gyenge, N.; Baranyi, T.; Ludmány, A.</p> <p></p> <p>The <span class="hlt">solar</span> <span class="hlt">active</span> longitudes were studied in the northern hemisphere in cycles 22 and 23 by using data of DPD sunspot catalogue. The <span class="hlt">active</span> longitudes are not fixed in the Carrington system, they have a well recognizable migration path between the descending phase of cycle 21 (from about 1984) and ascending phase of cycle 23 (until about 1996), out of this interval the migration path is ambiguous. The longitudinal distribution on both sides of the path has been computed and averaged for the length of the path. The so-called flip-flop phenomenon, when the <span class="hlt">activity</span> temporarily gets to the opposite longitude, can also be recognized. The widths of the <span class="hlt">active</span> domains are fairly narrow in the increasing and decaying phases of cycle 22, their half widths are about 20°-30° for both the main and secondary <span class="hlt">active</span> belts but it is more flat and stretched around the maximum with a half width of about 60°.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016GeoRL..43.6790K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016GeoRL..43.6790K&link_type=ABSTRACT"><span id="translatedtitle">Characteristics of <span class="hlt">solar</span> wind control on Jovian UV auroral <span class="hlt">activity</span> deciphered by long-term Hisaki EXCEED observations: Evidence of preconditioning of the magnetosphere?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kita, Hajime; Kimura, Tomoki; Tao, Chihiro; Tsuchiya, Fuminori; Misawa, Hiroaki; Sakanoi, Takeshi; Kasaba, Yasumasa; Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Yoshikawa, Ichiro; Fujimoto, Masaki</p> <p>2016-07-01</p> <p>While the Jovian magnetosphere is known to have the internal source for its <span class="hlt">activity</span>, it is reported to be under the <span class="hlt">influence</span> of the <span class="hlt">solar</span> wind as well. Here we report the statistical relationship between the total power of the Jovian ultraviolet aurora and the <span class="hlt">solar</span> wind properties found from long-term monitoring by the spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board the Hisaki satellite. Superposed epoch analysis indicates that auroral total power increases when an enhanced <span class="hlt">solar</span> wind dynamic pressure hits the magnetosphere. Furthermore, the auroral total power shows a positive correlation with the duration of a quiescent interval of the <span class="hlt">solar</span> wind that is present before a rise in the dynamic pressure, more than with the amplitude of dynamic pressure increase. These statistical characteristics define the next step to unveil the physical mechanism of the <span class="hlt">solar</span> wind control on the Jovian magnetospheric dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPD....4730503C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPD....4730503C"><span id="translatedtitle">A Study of <span class="hlt">Solar</span> Magnetic Fields Below the Surface, at the Surface, and in the <span class="hlt">Solar</span> Atmosphere - Understanding the Cause of Major <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chintzoglou, Georgios</p> <p>2016-05-01</p> <p>The fundamental processes regarding the origin, emergence and evolution of <span class="hlt">solar</span> magnetic fields as well as the generation of <span class="hlt">solar</span> <span class="hlt">activity</span> are largely unknown or remain controversial. In this dissertation, multiple important issues regarding <span class="hlt">solar</span> magnetism and <span class="hlt">activities</span> are addressed, based on advanced observations obtained by the AIA and HMI instruments aboard the SDO spacecraft.This dissertation addresses the 3D magnetic structure of complex emerging <span class="hlt">Active</span> Regions (ARs). In ARs the photospheric fields might show all aspects of complexity, from simple bipolar regions to extremely complex multipolar surface magnetic distributions. Here, we introduce a novel technique to infer the subphotospheric configuration of emerging magnetic flux tubes forming ARs on the surface. Using advanced 3D visualization tools with this technique on a complex flare and CME productive AR, we found that the magnetic flux tubes forming the complex AR may originate from a single progenitor flux tube in the SCZ. The complexity can be explained as a result of vertical and horizontal bifurcations that occurred on the progenitor flux tube.In addition, this dissertation proposes a new scenario on the origin of major <span class="hlt">solar</span> <span class="hlt">activity</span>. When more than one flux tubes are in close proximity to each other while they break through the photospheric surface, collision and shearing may occur as they emerge. Once this collisional shearing occurs between nonconjugated sunspots (opposite polarities not belonging to the same bipole), major <span class="hlt">solar</span> <span class="hlt">activity</span> is triggered. The collision and shearing occur due to the natural separation of polarities in emerging bipoles. In this continuous collision, more poloidal flux is added to the system effectively creating an expanding MFR into the corona, accompanied by filament formation above the PIL together with flare <span class="hlt">activity</span> and CMEs. Our results reject two popular scenarios on the possible cause of <span class="hlt">solar</span> eruptions (1) shearing motion between conjugate polarities, (2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22118756','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22118756"><span id="translatedtitle">THE EXPANSION OF <span class="hlt">ACTIVE</span> REGIONS INTO THE EXTENDED <span class="hlt">SOLAR</span> CORONA</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morgan, Huw; Jeska, Lauren; Leonard, Drew</p> <p>2013-06-01</p> <p>Advanced image processing of Large Angle and Spectrometric Coronagraph Experiment (LASCO) C2 observations reveals the expansion of the <span class="hlt">active</span> region closed field into the extended corona. The nested closed-loop systems are large, with an apparent latitudinal extent of 50 Degree-Sign , and expanding to heights of at least 12 R{sub Sun }. The expansion speeds are {approx}10 km s{sup -1} in the AIA/SDO field of view, below {approx}20 km s{sup -1} at 2.3 R{sub Sun }, and accelerate linearly to {approx}60 km s{sup -1} at 5 R{sub Sun }. They appear with a frequency of one every {approx}3 hr over a time period of around three days. They are not coronal mass ejections (CMEs) since their gradual expansion is continuous and steady. They are also faint, with an upper limit of 3% of the brightness of background streamers. Extreme ultraviolet images reveal continuous birth and expansion of hot, bright loops from a new <span class="hlt">active</span> region at the base of the system. The LASCO images show that the loops span a radial fan-like system of streamers, suggesting that they are not propagating within the main coronal streamer structure. The expanding loops brighten at low heights a few hours prior to a CME eruption, and the expansion process is temporarily halted as the closed field system is swept away. Closed magnetic structures from some <span class="hlt">active</span> regions are not isolated from the extended corona and <span class="hlt">solar</span> wind, but can expand to large heights in the form of quiescent expanding loops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4742553','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4742553"><span id="translatedtitle"><span class="hlt">Influencing</span> Factors of Thermogenic Adipose Tissue <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Guoqing; Sun, Qinghua; Liu, Cuiqing</p> <p>2016-01-01</p> <p>Obesity is an escalating public health challenge and contributes tremendously to the disease burden globally. New therapeutic strategies are required to alleviate the health impact of obesity-related metabolic dysfunction. Brown adipose tissue (BAT) is specialized for dissipating chemical energy for thermogenesis as a defense against cold environment. Intriguingly, the brown-fat like adipocytes that dispersed throughout white adipose tissue (WAT) in rodents and humans, called “brite” or “beige” adipocytes, share similar thermogenic characteristics to brown adipocytes. Recently, researchers have focused on cognition of these thermogenic adipose tissues. Some factors have been identified to regulate the development and function of thermogenic adipose tissues. Cold exposure, pharmacological conditions, and lifestyle can enhance non-shivering thermogenesis and metabolism via some mechanisms. However, environmental pollutants, such as ambient fine particulates and ozone, may impair the function of these thermogenic adipose tissues and thereby induce metabolic dysfunction. In this review, the origin, function and <span class="hlt">influencing</span> factors of thermogenic adipose tissues were summarized and it will provide insights into identifying new therapeutic strategies for the treatment of obesity and obesity-related diseases. PMID:26903879</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26903879','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26903879"><span id="translatedtitle"><span class="hlt">Influencing</span> Factors of Thermogenic Adipose Tissue <span class="hlt">Activity</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Guoqing; Sun, Qinghua; Liu, Cuiqing</p> <p>2016-01-01</p> <p>Obesity is an escalating public health challenge and contributes tremendously to the disease burden globally. New therapeutic strategies are required to alleviate the health impact of obesity-related metabolic dysfunction. Brown adipose tissue (BAT) is specialized for dissipating chemical energy for thermogenesis as a defense against cold environment. Intriguingly, the brown-fat like adipocytes that dispersed throughout white adipose tissue (WAT) in rodents and humans, called "brite" or "beige" adipocytes, share similar thermogenic characteristics to brown adipocytes. Recently, researchers have focused on cognition of these thermogenic adipose tissues. Some factors have been identified to regulate the development and function of thermogenic adipose tissues. Cold exposure, pharmacological conditions, and lifestyle can enhance non-shivering thermogenesis and metabolism via some mechanisms. However, environmental pollutants, such as ambient fine particulates and ozone, may impair the function of these thermogenic adipose tissues and thereby induce metabolic dysfunction. In this review, the origin, function and <span class="hlt">influencing</span> factors of thermogenic adipose tissues were summarized and it will provide insights into identifying new therapeutic strategies for the treatment of obesity and obesity-related diseases. PMID:26903879</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.2839Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.2839Y&link_type=ABSTRACT"><span id="translatedtitle">({The) <span class="hlt">Solar</span> System Large Planets <span class="hlt">influence</span> on a new Maunder Miniμm}</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yndestad, Harald; Solheim, Jan-Erik</p> <p>2016-04-01</p> <p>In 1890´s G. Spörer and E. W. Maunder (1890) reported that the <span class="hlt">solar</span> <span class="hlt">activity</span> stopped in a period of 70 years from 1645 to 1715. Later a reconstruction of the <span class="hlt">solar</span> <span class="hlt">activity</span> confirms the grand minima Maunder (1640-1720), Spörer (1390-1550), Wolf (1270-1340), and the minima Oort (1010-1070) and Dalton (1785-1810) since the year 1000 A.D. (Usoskin et al. 2007). These minimum periods have been associated with less irradiation from the Sun and cold climate periods on Earth. An identification of a three grand Maunder type periods and two Dalton type periods in a period thousand years, indicates that sooner or later there will be a colder climate on Earth from a new Maunder- or Dalton- type period. The cause of these minimum periods, are not well understood. An expected new Maunder-type period is based on the properties of <span class="hlt">solar</span> variability. If the <span class="hlt">solar</span> variability has a deterministic element, we can estimate better a new Maunder grand minimum. A random <span class="hlt">solar</span> variability can only explain the past. This investigation is based on the simple idea that if the <span class="hlt">solar</span> variability has a deterministic property, it must have a deterministic source, as a first cause. If this deterministic source is known, we can compute better estimates the next expected Maunder grand minimum period. The study is based on a TSI ACRIM data series from 1700, a TSI ACRIM data series from 1000 A.D., sunspot data series from 1611 and a <span class="hlt">Solar</span> Barycenter orbit data series from 1000. The analysis method is based on a wavelet spectrum analysis, to identify stationary periods, coincidence periods and their phase relations. The result shows that the TSI variability and the sunspots variability have deterministic oscillations, controlled by the large planets Jupiter, Uranus and Neptune, as the first cause. A deterministic model of TSI variability and sunspot variability confirms the known minimum and grand minimum periods since 1000. From this deterministic model we may expect a new Maunder type sunspot</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920020961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920020961"><span id="translatedtitle">Investigation of <span class="hlt">solar</span> <span class="hlt">active</span> regions at high resolution by balloon flights of the <span class="hlt">solar</span> optical universal polarimeter, definition phase</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tarbell, Theodore D.; Topka, Kenneth P.</p> <p>1992-01-01</p> <p>The definition phase of a scientific study of <span class="hlt">active</span> regions on the sun by balloon flight of a former Spacelab instrument, the <span class="hlt">Solar</span> Optical Universal Polarimeter (SOUP) is described. SOUP is an optical telescope with image stabilization, tunable filter and various cameras. After the flight phase of the program was cancelled due to budgetary problems, scientific and engineering studies relevant to future balloon experiments of this type were completed. High resolution observations of the sun were obtained using SOUP components at the Swedish <span class="hlt">Solar</span> Observatory in the Canary Islands. These were analyzed and published in studies of <span class="hlt">solar</span> magnetic fields and <span class="hlt">active</span> regions. In addition, testing of low-voltage piezoelectric transducers was performed, which showed they were appropriate for use in image stabilization on a balloon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Ap%26SS.361...78S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Ap%26SS.361...78S"><span id="translatedtitle">Study of intensive <span class="hlt">solar</span> flares in the rise phase of <span class="hlt">solar</span> cycle 23 and 24 and other <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Subramanian, S. Prasanna; Shanmugaraju, A.</p> <p>2016-02-01</p> <p>We present a statistical study and comparison on the properties of intensive <span class="hlt">solar</span> flares (>M5.0 X-ray flare), decameter-hectometric (DH) wavelength [frequency, 1-14 MHz] type II radio bursts and <span class="hlt">solar</span> energetic particle (SEP) events during the rising phase of <span class="hlt">solar</span> cycles 23 and 24. The period of study is May 1996-November 2000 for <span class="hlt">solar</span> cycle 23 and December 2008-June 2013 for <span class="hlt">solar</span> cycle 24. Apart from reported weakness of <span class="hlt">solar</span> cycle 24 compared to the cycle 23, we noted the following differences between the two cycles on the properties of these <span class="hlt">activities</span> associated with intensive flares: (i) The reduction in the number of intensive flares (>M5.0 class) in cycle 24 is ˜34 %, similar to the reduction in sunspot number reported by Gopalswamy et al. (2014a); (ii) The slightly higher mean starting-frequency (4.15 MHz) and lower ending frequency (0.58 MHz) in cycle 24 compared to those of cycle 23 (2.63 and 0.89 MHz, respectively) indicate that the radio emission of this cycle started closer to the Sun and the CME-shock travelled farther away from the Sun in cycle 24; (iv) Cycle 23 produced a nearly equal number of SEP events as cycle 24 during the rising phase. The correlation between SEP intensity and CME speed is more prominent in cycle 23 (CC=0.7) than in cycle 24 (CC=0.3).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090026490','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090026490"><span id="translatedtitle">Overview of the Temperature Response in the Mesosphere and Lower Thermosphere to <span class="hlt">Solar</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beig, Gufran; Scheer, Juergen; Mlynczak, Martin G.; Keckhut, Philippe</p> <p>2008-01-01</p> <p>The natural variability in the terrestrial mesosphere needs to be known to correctly quantify global change. The response of the thermal structure to <span class="hlt">solar</span> <span class="hlt">activity</span> variations is an important factor. Some of the earlier studies highly overestimated the mesospheric <span class="hlt">solar</span> response. Modeling of the mesospheric temperature response to <span class="hlt">solar</span> <span class="hlt">activity</span> has evolved in recent years, and measurement techniques as well as the amount of data have improved. Recent investigations revealed much smaller <span class="hlt">solar</span> signatures and in some case no significant <span class="hlt">solar</span> signal at all. However, not much effort has been made to synthesize the results available so far. This article presents an overview of the energy budget of the mesosphere and lower thermosphere (MLT) and an up-to-date status of <span class="hlt">solar</span> response in temperature structure based on recently available observational data. An objective evaluation of the data sets is attempted and important factors of uncertainty are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Ge%26Ae..53..971I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Ge%26Ae..53..971I"><span id="translatedtitle">Complex <span class="hlt">active</span> regions as the main source of extreme and large <span class="hlt">solar</span> proton events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishkov, V. N.</p> <p>2013-12-01</p> <p>A study of <span class="hlt">solar</span> proton sources indicated that <span class="hlt">solar</span> flare events responsible for ≥2000 pfu proton fluxes mostly occur in complex <span class="hlt">active</span> regions (CARs), i.e., in transition structures between <span class="hlt">active</span> regions and <span class="hlt">activity</span> complexes. Different classes of similar structures and their relation to <span class="hlt">solar</span> proton events (SPEs) and evolution, depending on the origination conditions, are considered. Arguments in favor of the fact that sunspot groups with extreme dimensions are CARs are presented. An analysis of the flare <span class="hlt">activity</span> in a CAR resulted in the detection of "physical" boundaries, which separate magnetic structures of the same polarity and are responsible for the independent development of each structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5684913','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5684913"><span id="translatedtitle"><span class="hlt">Solar</span> Energy Education. Renewable energy <span class="hlt">activities</span> for chemistry and physics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1985-01-01</p> <p>Information on renewable energy sources is provided for students in this teachers' guide. With the chemistry and physics student in mind, <span class="hlt">solar</span> energy topics such as absorber plate coatings for <span class="hlt">solar</span> collectors and energy collection and storage methods are studied. (BCS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910016661','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910016661"><span id="translatedtitle">Outline of the <span class="hlt">Solar</span> System: <span class="hlt">Activities</span> for elementary students</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hartsfield, J.; Sellers, M.</p> <p>1990-01-01</p> <p>An introduction to the <span class="hlt">solar</span> system for the elementary school student is given. The introduction contains historical background, facts, and pertinent symbols concerning the sun, the nine major planets and their moons, and information about comets and asteroids. Aids to teaching are given, including a <span class="hlt">solar</span> system crossword puzzle with answers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760021654','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760021654"><span id="translatedtitle">Study of the relationship between <span class="hlt">solar</span> <span class="hlt">activity</span> and terrestrial weather</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sturrock, P. A.; Brueckner, G. E.; Dickinson, R. E.; Fukuta, N.; Lanzerotti, L. J.; Lindzen, R. S.; Park, C. G.; Wilcox, J. M.</p> <p>1976-01-01</p> <p>Evidence for some connection between weather and <span class="hlt">solar</span> related phenomena is presented. Historical data of world wide temperature variations with relationship to change in <span class="hlt">solar</span> luminosity are examined. Several test methods for estimating the statistical significance of such phenomena are discussed in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010051278&hterms=Solar+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSolar%2BEnergy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010051278&hterms=Solar+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSolar%2BEnergy"><span id="translatedtitle"><span class="hlt">Influence</span> of the Surface and Cloud Nonuniformities in the <span class="hlt">Solar</span> Energy Fluxes in the Arctic</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rozwadowska, A.; Cahalan, R. F.; Einaudi, Franco (Technical Monitor)</p> <p>2000-01-01</p> <p><span class="hlt">Solar</span> energy fluxes reaching the surface and absorbed by it are basic components of the energy balance of the Arctic. They depend mainly on the <span class="hlt">solar</span> zenith angle, a state of the atmosphere, especially the cloudiness, and the surface albedo. However, they can also be modified by variabilities in the surface albedo and cloud optical thickness. The surface of the Arctic can be highly nonuniform. The surface of the Arctic Ocean, which covers the huge part of the Arctic can be view as a mosaic of sea water, sea ice, snow and, in the melting period, melting ponds. In our paper, results are presented of Monte Carlo simulations of the expected <span class="hlt">influence</span> of nonuniform cloud structure and nonuniform surface albedo on radiative fluxes at the Arctic surface. In particular, the plane parallel biases in the surface absorptance and atmospheric transmittance are studied. The bias is defined as the difference between the real absorptance or transmittance (i.e. nonuniform conditions) averaged over a given area, and the uniform or plane parallel case with the same mean cloud optical thickness and the same mean surface albedo. The dependence of the biases is analysed with respect to the following: domain averaged values of the cloud optical thickness and surface albedo, scales of their spatial variabilities, correlation between cloud optical thickness and cloud albedo variabilities, cloud height, and the <span class="hlt">solar</span> zenith angle. Ranges of means and standard deviations of the input parameters typical of Arctic conditions are obtained from the SHEBA experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AIPC.1311..337D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AIPC.1311..337D&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Influence</span> of Magnetite Nanoparticles on Human Leukocyte <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Džarová, Anežka; Dubničková, Martina; Závišová, Vlasta; Koneracká, Martina; Kopčanský, Peter; Gojzewski, Hubert; Timko, Milan</p> <p>2010-12-01</p> <p>Chemically synthesized magnetite particles coated by sodium oleate and PEG (MNP), and magnetosomes (MS) <span class="hlt">influence</span> the process of phagocytosis and the metabolic <span class="hlt">activity</span> (lysozyme and peroxidase <span class="hlt">activity</span>) in leukocytes. Lysozyme <span class="hlt">activity</span> is oxygen-independent liquidation mechanisms of engulfed microorganism, peroxidase <span class="hlt">activity</span> is an oxygen-dependent mechanism. Both tested types of nanoparticles lysed leukocyte cells during incubation. MNP at concentrations of 10 and 20 μg/mL lysed almost all leukocytes and their cell viability was in the 14±0.05% range. On the other hand MS begin to <span class="hlt">influence</span> leukocytes <span class="hlt">activity</span> at the concentration of 1 μg/ml and this <span class="hlt">influence</span> grows with increasing concentration up to 20 μg/ml. MS are more suitable for biological applications than MNP which are more aggressive material than MS. MS should not be used above 10 μg/mL.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..267K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..267K"><span id="translatedtitle">Investigation of the <span class="hlt">solar</span> <span class="hlt">influence</span> on clean and dusty CO2-ice under Martian conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaufmann, E.; Hagermann, A.; Wolters, S.</p> <p>2015-10-01</p> <p>CO2 is the main component of the Martian atmosphere. Therefore the polar caps are - depending on hemisphere and season - partially or totally covered with CO2-ice. In contrast to rock and soil surface layers, which absorb and reflect incoming <span class="hlt">solar</span> radiation immediately at the surface, ices are partially transparent in the visible spectral range, while they are opaque in the infrared. These properties are responsible for the so-called "Solid- State Greenhouse Effect" (SSGE). The SSGE may have a major <span class="hlt">influence</span> on the sublimation and recondensation of CO2 and its circulation in the Martian atmosphere. Our work will concentrate on the <span class="hlt">influence</span> of the SSGE on CO2-ice under Martian like conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568686','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568686"><span id="translatedtitle">High-resolution analysis of upper Miocene lake deposits: Evidence for the <span class="hlt">influence</span> of Gleissberg-band <span class="hlt">solar</span> forcing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kern, Andrea K.; Harzhauser, Mathias; Soliman, Ali; Piller, Werner E.; Mandic, Oleg</p> <p>2013-01-01</p> <p>A high-resolution multi-proxy analysis was conducted on a 1.5-m-long core of Tortonian age (~ 10.5 Ma; Late Miocene) from Austria (Europe). The lake sediments were studied with a 1-cm resolution to detect all small-scale variations based on palynomorphs (pollen and dinoflagellate cysts), ostracod abundance, geochemistry (carbon and sulfur) and geophysics (magnetic susceptibility and natural gamma radiation). Based on an already established age model for a longer interval of the same core, this sequence can be limited to approx. two millennia of Late Miocene time with a resolution of ~ 13.7 years per sample. The previous study documented the presence of <span class="hlt">solar</span> forcing, which was verified within various proxies on this 1.5-m core by a combination of REDFIT spectra and Gaussian filters. Significant repetitive signals ranged in two discrete intervals corresponding roughly to 55–82 and 110–123 years, fitting well within the lower and upper Gleissberg cycle ranges. Based on these results, the environmental changes along the 2000-year Late Miocene sequence are discussed. No major ecological turnovers are expected in this very short interval. Nonetheless, even within this brief time span, dinoflagellates document rapid changes between oligotrophic and eutrophic conditions, which are frequently coupled with lake stratification and dysoxic bottom waters. These phases prevented ostracods and molluscs from settling and promoted the <span class="hlt">activity</span> of sulfur bacteria. The pollen record indicates rather stable wetland vegetation with a forested hinterland. Shifts in the pollen spectra can be mainly attributed to variations in transport mechanisms. These are represented by a few phases of fluvial input but mainly by changes in wind intensity and probably also wind direction. Such <span class="hlt">influence</span> is most likely caused by <span class="hlt">solar</span> cycles, leading to a change in source area for the input into the lake. Furthermore, these <span class="hlt">solar</span>-induced variations seem to be modulated by longer <span class="hlt">solar</span> cycles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010cosp...38..140Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010cosp...38..140Z&link_type=ABSTRACT"><span id="translatedtitle">The role of <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span> in the changes of the climatic characteristics of troposphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zherebtsov, Gelii; Rubtsova, Olga; Kovalenko, Vladimir; Molodykh, Sergey</p> <p></p> <p>The main points of the model of the <span class="hlt">solar</span> <span class="hlt">activity</span> effect on the Earth climatic system are presented. The key concept of the model is heliogeophysical disturbance effect on the Earth climatic system parameters, which control energy flux, going from the Earth to the space, in high-latitude areas. The model is based on the physical mechanism of heliogeophysical factors' <span class="hlt">influence</span> on climatic characteristics and atmospheric circulation in the high-latitude troposphere through the atmospheric electricity. In accordance with this mechanism, the at-mospheric electricity parameters in the high latitudes depend on the <span class="hlt">solar</span> <span class="hlt">activity</span>; at the same time, they <span class="hlt">influence</span> the altitude distribution of charged condensation nuclei in the tropo-sphere, as well as the cloudiness formation and radiation balance and atmospheric circulation. NCEP/NCAR Reanalysis and CMAP data were used to analyze particularities and regularities of long-term variations in amount of precipitation in 1950-2007. Global decrease in amount of precipitation was found to dominate till late 1990s. It started increasing only 10 years ago. Peculiarities of distribution and long-term variations in amount of precipitation in different latitudes and longitudes were also considered. Correlation analysis of connection between the amount of precipitation and the geomagnetic <span class="hlt">activity</span> and atmospheric circulation was carried out. The connection was found out to depend on a season. Cold periods in the northern hemisphere were characterized by a direct relationship between the geomagnetic <span class="hlt">activity</span> and amount of precipitation in high latitudes, whereas a negative relationship was observed in sube-quatorial latitudes. In the framework of the model considered, the analysis results are presented and discussed of regularities of variations in geomagnetic <span class="hlt">activity</span> and troposphere thermobaric characteristics for 1900-2007. It is showed that a continuous increase of the Earth climatic system heat content has been observed from 1910</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Ap%26SS.361..295Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Ap%26SS.361..295Z&link_type=ABSTRACT"><span id="translatedtitle">Geomagnetic and <span class="hlt">solar</span> <span class="hlt">activity</span> dependence of ionospheric upflowing O+: FAST observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, K.; Jiang, Y.; Chen, K. W.; Huang, L. F.</p> <p>2016-09-01</p> <p>This paper investigates the dependence of the occurrence frequency of ionospheric upflowing oxygen (O+) ions on the sunspot cycle and geomagnetic <span class="hlt">activity</span>. We examine the upflows response to the geomagnetic disturbances as well as the <span class="hlt">influence</span> of the ion energy factor in controlling the magnitude of the occurrence frequency and the net energy flux. We discuss the spatial distribution of the upflow occurrence frequency and construct a regression model as a function of the magnetic latitude. The results show an overall enhancement of the upflow occurrence frequency during magnetically disturbed periods and indicate that the high-occurrence area spreads out from the source regions during magnetically quiet periods. The high-occurrence areas are located at 70° magnetic latitude (mLat) in the dayside auroral oval zone and between 76-80° mLat in the dayside polar cusp region. In the nightside auroral oval zone, these areas are near 60° mLat, penetrating further equatorward to 55° mLat during magnetically disturbed periods. High energy (≥1 keV) upflowing ions are common in the nightside auroral oval zone while low energy (<1 keV) upflowing ions are found escaping from the high latitude dayside cusp region. A Gaussian function is shown to be a good fit to the occurrence frequency over the magnetic latitude. For high energy upflowing O+ ions, the occurrence frequency exhibits a single peak located at about 60° mLat in the nightside auroral oval zone while for low energy upflowing O+ ions, it exhibits two peaks, one near 60° mLat in the auroral oval zone and the other near 78° mLat in the cusp region. We study the <span class="hlt">solar</span> <span class="hlt">activity</span> dependence by analyzing the relationship between the upflow occurrence frequency and the sunspot number (RZ). The statistical result shows that the frequency decreases with declining <span class="hlt">solar</span> <span class="hlt">activity</span> level, from ˜30 % at <span class="hlt">solar</span> maximum to ˜5 % at <span class="hlt">solar</span> minimum. In addition, the correlation coefficient between the occurrence frequency and RZ</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010048761&hterms=paradigm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dparadigm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010048761&hterms=paradigm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dparadigm"><span id="translatedtitle">Plasma Beta Above a <span class="hlt">Solar</span> <span class="hlt">Active</span> Region: Rethinking the Paradigm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gary, G. Allen; Whitaker, Ann F. (Technical Monitor)</p> <p>2001-01-01</p> <p>In this paper, we present a model of the plasma beta above an <span class="hlt">active</span> region and discuss its consequences in terms of coronal magnetic field modeling. The beta-plasma model is representative and derived from a collection of sources. The resulting beta variation with height is used to emphasize the assumption that the magnetic pressure dominates over the plasma pressure must be carefully considered depending on what part of the <span class="hlt">solar</span> atmosphere is being considered. This paper points out (1) that the paradigm that the coronal magnetic field can be constructed from a force-free magnetic field must be used in the correct context, since the forcefree region is sandwiched between two regions which have beta greater than 1, (2) that the chromospheric MgIICIV magnetic measurements occur near the beta-minimum, and (3) that, moving from the photosphere upwards, beta can return to 1 at relatively low coronal heights, e.g. R approximately 1.2R(sub)s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AdSpR..42..610A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AdSpR..42..610A&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Solar</span> <span class="hlt">activity</span> variations of ionosonde measurements and modeling results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Altadill, D.; Arrazola, D.; Blanch, E.; Buresova, D.</p> <p>2008-08-01</p> <p>The time series of hourly electron density profiles N(h) obtained at several mid-latitude stations in Europe have been used to obtain N(h) profiles on a monthly basis and to extract both the expected bottomside parameters and a proxy of the ionospheric variability as functions of time and height. With these data we present advances on a “Local Model” technique for the parameters B0 and B1, its applicability to other ionospheric stations, to other bottomside ionospheric parameters, and to modeling the time/height variability of the profile. The Local Model (LM) is an empirical model based on the experimental results of the <span class="hlt">solar</span> <span class="hlt">activity</span> dependence of the daily and seasonal behavior of the above parameters. The LM improves the IRI-2001 prediction of the B0 and B1 by factor of two at mid-latitudes. Moreover, the LM can be used to simulate other ionospheric parameters and to build mean N(h) profiles and the deviations from them. The modeling of both the average N(h) profiles and their deviations is an useful tool for ionospheric model users who want to know both the expected patterns and their deviations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000074663&hterms=geocentric&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeocentric','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000074663&hterms=geocentric&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeocentric"><span id="translatedtitle"><span class="hlt">Solar</span> Wind <span class="hlt">Influence</span> on the Oxygen Content of Ion Outflow in the High Altitude Polar Cap During <span class="hlt">Solar</span> Minimum Conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elliott, Heather A.; Comfort, Richard H.; Craven, Paul D.; Chandler, Michael O.; Moore, Thomas E.</p> <p>2000-01-01</p> <p>We correlate <span class="hlt">solar</span> wind and IMF properties with the properties of O(+) and H(+) in the polar cap in early 1996 during <span class="hlt">solar</span> minimum conditions at altitudes between 5.5 and 8.9 Re geocentric using the Thermal Ion Dynamics Experiment (TIDE) on the POLAR satellite. Throughout the high altitude polar cap, we observe H(+) to be more abundant than O(+). H(+) is a significant fraction of both the ionosphere and the <span class="hlt">solar</span> wind, and O(+) is not a significant species in the <span class="hlt">solar</span> wind. O(+) is the major species in the ionosphere so the faction of O(+) present in the magnetosphere is commonly used as a measure of the ionospheric contribution to the magnetosphere. For these reasons, 0+ is of primary interest in this study. We observe O(+) to be most abundant at lower latitudes when the <span class="hlt">solar</span> wind speed is low (and low Kp), and at higher <span class="hlt">solar</span> wind speeds (and high Kp) O(+) is observed across most of the polar cap. We also find that O(+) density and parallel flux are well organized by <span class="hlt">solar</span> wind dynamic pressure; they both increase with <span class="hlt">solar</span> wind dynamic pressure. H(+) is not as highly correlated with <span class="hlt">solar</span> wind and IMF parameters, but H(+) density and parallel flux have some negative correlation with IMF By, and some positive correlation with VswBIMF. In this <span class="hlt">solar</span> minimum data set, H(+) is dominant so that contributions of this plasma to the plasma sheet would have a very low O(+) to H(+) ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IAUS..286..200E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IAUS..286..200E"><span id="translatedtitle">Extremely low geomagnetic <span class="hlt">activity</span> during the recent deep <span class="hlt">solar</span> cycle minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Echer, E.; Tsurutani, B. T.; Gonzalez, W. D.</p> <p>2012-07-01</p> <p>The recent <span class="hlt">solar</span> minimum (2008-2009) was extreme in several aspects: the sunspot number, R z , interplanetary magnetic field (IMF) magnitude B o and <span class="hlt">solar</span> wind speed V sw were the lowest during the space era. Furthermore, the variance of the IMF southward B z component was low. As a consequence of these exceedingly low <span class="hlt">solar</span> wind parameters, there was a minimum in the energy transfer from <span class="hlt">solar</span> wind to the magnetosphere, and the geomagnetic <span class="hlt">activity</span> ap index reached extremely low levels. The minimum in geomagnetic <span class="hlt">activity</span> was delayed in relation to sunspot cycle minimum. We compare the <span class="hlt">solar</span> wind and geomagnetic <span class="hlt">activity</span> observed in this recent minimum with previous <span class="hlt">solar</span> cycle values during the space era (1964-2010). Moreover, the geomagnetic <span class="hlt">activity</span> conditions during the current minimum are compared with long term variability during the period of available geomagnetic observations. The extremely low geomagnetic <span class="hlt">activity</span> observed in this <span class="hlt">solar</span> minimum was previously recorded only at the end of XIX century and at the beginning of the XX century, and this might be related to the Gleissberg (80-100 years) <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770041233&hterms=separate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dseparate%257E','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770041233&hterms=separate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dseparate%257E"><span id="translatedtitle">Skylab observations of X-ray loops connecting separate <span class="hlt">active</span> regions. [<span class="hlt">solar</span> <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chase, R. C.; Krieger, A. S.; Svestka, Z.; Vaiana, G. S.</p> <p>1976-01-01</p> <p>One hundred loops interconnecting 94 separate <span class="hlt">active</span> <span class="hlt">solar</span> regions detectable in soft X-rays were identified during the Skylab mission. While close <span class="hlt">active</span> regions are commonly interconnected with loops, the number of such interconnections decreases steeply for longer distances; the longest interconnecting loop observed in the Skylab data connected regions separated by 37 deg. Several arguments are presented which support the point of view that this is the actual limit of the size of magnetic interconnections between <span class="hlt">active</span> regions. No sympathetic flares could be found in the interconnected regions. These results cast doubt on the hypothesis that accelerated particles can be guided in interconnecting loops from one <span class="hlt">active</span> region to another over distances of 100 deg or more and eventually produce sympathetic flares in them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.515C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.515C"><span id="translatedtitle">Ionospheric Response to Geomagnetic <span class="hlt">Activity</span> during 2007-2009 <span class="hlt">Solar</span> Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yiding; Liu, Libo; Huijun Le, lake709.; Wan, Weixing</p> <p></p> <p>The significant effect of weaker geomagnetic <span class="hlt">activity</span> on ionospheric day-to-day variability during 2007-2009 <span class="hlt">solar</span> minimum was highlighted by investigating the response of global electron content (GEC) to geomagnetic <span class="hlt">activity</span> index Ap. A case distinctly manifests the modulation of recurrent weaker geomagnetic disturbance on GEC during the <span class="hlt">solar</span> minimum. Statistical analyses indicate that the effect of weaker geomagnetic <span class="hlt">activity</span> on GEC day-to-day variability is significant during 2007-2009, even under relatively quiet geomagnetic <span class="hlt">activity</span> condition, while geomagnetic <span class="hlt">activity</span> effect on GEC is not prominent during 2003-2005 <span class="hlt">solar</span> cycle descending phase except under strong geomagnetic disturbance condition. Nevertheless, statistically the most important effect on GEC day-to-day variability during 2007-2009 comes from the factors other than geomagnetic <span class="hlt">activity</span> and <span class="hlt">solar</span> EUV irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4888C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4888C"><span id="translatedtitle">Ionospheric Response to Geomagnetic <span class="hlt">Activity</span> during 2007-2009 <span class="hlt">Solar</span> Minimum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yiding; Liu, Libo; Le, Huijun; Wan, Weixing</p> <p>2014-05-01</p> <p>The significant effect of weaker geomagnetic <span class="hlt">activity</span> on ionospheric day-to-day variability during 2007-2009 <span class="hlt">solar</span> minimum was highlighted by investigating the response of global electron content (GEC) to geomagnetic <span class="hlt">activity</span> index Ap. A case distinctly manifests the modulation of recurrent weaker geomagnetic disturbance on GEC during the <span class="hlt">solar</span> minimum. Statistical analyses indicate that the effect of weaker geomagnetic <span class="hlt">activity</span> on GEC day-to-day variability is significant during 2007-2009, even under relatively quiet geomagnetic <span class="hlt">activity</span> condition, while geomagnetic <span class="hlt">activity</span> effect on GEC is not prominent during 2003-2005 <span class="hlt">solar</span> cycle descending phase except under strong geomagnetic disturbance condition. Nevertheless, statistically the most important effect on GEC day-to-day variability during 2007-2009 comes from the factors other than geomagnetic <span class="hlt">activity</span> and <span class="hlt">solar</span> EUV irradiance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SpWea...8.3006M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SpWea...8.3006M"><span id="translatedtitle">Geomagnetic <span class="hlt">influence</span> on aircraft radiation exposure during a <span class="hlt">solar</span> energetic particle event in October 2003</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mertens, Christopher J.; Kress, Brian T.; Wiltberger, Michael; Blattnig, Steve R.; Slaba, Tony S.; Solomon, Stanley C.; Engel, M.</p> <p>2010-03-01</p> <p>We present initial results from the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model during the Halloween 2003 superstorm. The objective of NAIRAS is to produce global, real-time, data-driven predictions of ionizing radiation for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. We have conducted a case study of radiation exposure during a high-energy <span class="hlt">solar</span> energetic particle (SEP) event in October 2003. The purpose of the case study is to quantify the important <span class="hlt">influences</span> of the storm time and quiet time magnetospheric magnetic field on high-latitude SEP atmospheric radiation exposure. The Halloween 2003 superstorm is an ideal event to study magnetospheric <span class="hlt">influences</span> on atmospheric radiation exposure since this event was accompanied by a major magnetic storm which was one of the largest of <span class="hlt">solar</span> cycle 23. We find that neglecting geomagnetic storm effects during SEP events can underestimate the high-latitude radiation exposure from nearly 15% to over a factor of 2, depending on the flight path relative to the magnetosphere open-closed boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750024923','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750024923"><span id="translatedtitle">H-alpha synoptic charts of <span class="hlt">solar</span> <span class="hlt">activity</span> during the first year of <span class="hlt">solar</span> cycle 20, October 1964 - August 1965. [Skylab program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcintosh, P. S.</p> <p>1975-01-01</p> <p><span class="hlt">Solar</span> <span class="hlt">activity</span> during the period October 28, 1964 through August 27, 1965 is presented in the form of charts for each <span class="hlt">solar</span> rotation constructed from observations made with the chromospheric H-alpha spectra line. These H-alpha synoptic charts are identical in format and method of construction to those published for the period of Skylab observations. The sunspot minimum marking the start of <span class="hlt">Solar</span> Cycle 20 occurred in October, 1964; therefore, charts represent <span class="hlt">solar</span> <span class="hlt">activity</span> during the first year of this <span class="hlt">solar</span> cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..299G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..299G"><span id="translatedtitle">A decrease in <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span> from cycle 19 to cycle 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gvishiani, A. D.; Starostenko, V. I.; Sumaruk, Yu. P.; Soloviev, A. A.; Legostaeva, O. V.</p> <p>2015-05-01</p> <p>Variations in the <span class="hlt">solar</span> and geomagnetic <span class="hlt">activity</span> from cycle 19 to cycle 24 were considered based on data from the magnetic observatories of the Russian-Ukrainian INTERMAGNET segment and international centers of data on <span class="hlt">solar</span>-terrestrial physics. It has been indicated that <span class="hlt">activity</span> decreases over the course of time. This is especially evident during the cycle 24 growth phase. The possible causes and consequences of a decrease in geomagnetic <span class="hlt">activity</span> were analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E.139B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E.139B&link_type=ABSTRACT"><span id="translatedtitle">A Study of Tropical Cyclones over India (Bay of Bengal and Arabian Sea) and <span class="hlt">Solar</span> <span class="hlt">Influence</span> on It</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banerjee, Dhruba</p> <p>2016-07-01</p> <p>A prominent example of extreme weather event in India is Cyclonic Storm. In this paper annual variation of tropical Cyclonic Storm (CS), Severe Cyclonic Storm (SCS), Very Severe Cyclonic Storm (VSCS) and Super Cyclonic Storm (SuCS) over Bay Of Bengal (BOB) and Arabian Sea (ARS) during last 20 years (1990-2009) have been analyzed .The analysis revels that the total number of cyclone (TNC) has increased with high rate(gradient being +1.67 per year) and although C.S. is more over BOB than that over ARS.The rate of increase of C.S. over Arabian Sea is more than that over Bay of Bengal. Furthermore, two interesting features have been noted: (i) Monsoon tends to prohibit the formation of C.S (ii) Cyclonic Storm(C.S.) increases with the increase of Global Sea Surface Temperature (GSST) during said period.. Attempt has also been made to find out the <span class="hlt">influence</span> of <span class="hlt">solar</span> <span class="hlt">activity</span> on these extreme weather events. Keeping in mind that the Sun Spot Number (SSN) is an indicator of the strength of <span class="hlt">solar</span> effects, it has been found that in most of the times the high value of SSN is associated with small number of total cyclone (C.S.). Specifically, when only the years of high Sun's Spot Number (approximately greater than 90) are taken into consideration then Correlation Coefficient (C.C.) between SSN and number of cyclones comes out to be quite high (-0.78) significance at 99.99% level while Correlation Coefficient (C.C.) of cyclones with time is 0.53 and with SSN < 60 it is..095 . Thus it appears that although C.S. frequency is increasing with time, Sun's Spot's <span class="hlt">influence</span> is such that it basically opposes the formation of cyclone provided SSN exceeds certain critical value (roughly 90). In principle, this is very important for any such event, and it is consistent with the trend of different phenomena occurring in nature. Key words: India, cyclone, <span class="hlt">solar</span> <span class="hlt">influence</span>, Critical Sun's Spot Number</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850016254&hterms=physical+activity+academic+achievement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dphysical%2Bactivity%2Bacademic%2Bachievement','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850016254&hterms=physical+activity+academic+achievement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dphysical%2Bactivity%2Bacademic%2Bachievement"><span id="translatedtitle">Coupling of the <span class="hlt">solar</span> wind to measures of magnetic <span class="hlt">activity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcpherron, R. L.; Fay, R. A.; Garrity, C. R.; Bargatze, L. F.; Clauer, C. R.; Searls, C.; Baker, D. N.</p> <p>1984-01-01</p> <p>Linear prediction filtering was used to generate empirical response functions relating the <span class="hlt">solar</span> wind electric field to the magnetic indices, AL, AU, Dst and ASYM. The empirical response functions were convolved with <span class="hlt">solar</span> wind observations obtained during the International Magnetospheric Study to predict the indices. The predictions are compared with the observed indices during two, 3-day intervals. Differences between the observed and predicted indices are discussed in terms of the linear assumption and in terms of physical processes other than direct <span class="hlt">solar</span> wind-magnetosphere interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6748292','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6748292"><span id="translatedtitle">Socio-economic and communication factors <span class="hlt">influencing</span> the diffusion of <span class="hlt">solar</span>-energy equipment among California homeowners</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mbindyo, J.M.</p> <p>1981-01-01</p> <p>This dissertation explores the <span class="hlt">influence</span> of socio-economic, communication, and social-psychological factors on the diffusion of <span class="hlt">solar</span>-energy equipment among California homeowners. There were four specific objectives: (1) to critique previous studies on the diffusion of <span class="hlt">solar</span> technology; (2) to critique fundamental aspects of current diffusion models and to formulate an alternative diffusion perspective; (3) to use the proposed theoretical perspective to predict <span class="hlt">solar</span> diffusion; and (4) to test certain of the proposed predictions about <span class="hlt">solar</span> diffusion. Data used to test some of the predictions were based on a state-wide random survey of 812 California homeowners. The dissertation presents two major findings. First, some of the best predictors of the <span class="hlt">solar</span>-diffusion process were found to be age, socio-economic status, knowing <span class="hlt">solar</span> owners, ownership of a swimming pool, utility costs, efficacy towards the energy situation, voluntary simplicity, energy consciousness, community size, and perceived community interest in <span class="hlt">solar</span>. Second, these predictors were found to be strongly related to socio-economic status. The present study argues that these predictors are in fact post indicators of socio-economic status. Thus, whereas many of the previous studies tended to underestimate the <span class="hlt">influence</span> of socio-economic factors, this study was able to demonstrate the crucial <span class="hlt">influence</span> of socio-economic factors in determining the rate and pattern of <span class="hlt">solar</span> diffusion. The data show that household <span class="hlt">solar</span>-energy equipment is basically an innovation for high and medium socio-economic groups. The implications of these findings with regard to previous studies, policy, and future research are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA51A2154Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA51A2154Z"><span id="translatedtitle">Study of the <span class="hlt">Influences</span> of the Ionospheric Responses to the <span class="hlt">Solar</span> Flares by the <span class="hlt">Solar</span> Flare Characteristics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, J.; Ridley, A. J.</p> <p>2012-12-01</p> <p>Electron densities in the ionosphere increase during <span class="hlt">solar</span> flares due to the sudden increase in the <span class="hlt">solar</span> irradiance at soft X-ray and extreme ultraviolet wavelengths. In this study, we perform simulations for a list of <span class="hlt">solar</span> flares with different classes and locations on the <span class="hlt">solar</span> disk (center-to-limb variations) using the Global Ionosphere and Thermosphere Model (GITM). First, we make an analysis of magnitudes and distribution of the TEC perturbations due to different <span class="hlt">solar</span> flares. <span class="hlt">Solar</span> flares occurring in different seasons are chosen from the list in order to examine how perturbations of electron densities depend on altitudes (E and F regions), latitudes (seasonal variations) and longitudes (sunrise, dayside and sunset), as well as the time dependences of the increasing and decaying of the electron densities around the flares. Also, we investigate the TEC data by the global GPS network from the Madrigal database for the <span class="hlt">solar</span> flares on the list, determining the characteristics of <span class="hlt">solar</span> flare that would allow them to be detected by the ground-based GPS observations. The TEC data by GPS and by GITM are compared to determine how well the modeling and observations match each other during different <span class="hlt">solar</span> flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JASS...30...43O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JASS...30...43O"><span id="translatedtitle">Dependence of Quiet Time Geomagnetic <span class="hlt">Activity</span> Seasonal Variation on the <span class="hlt">Solar</span> Magnetic Polarity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, Suyeon</p> <p>2013-03-01</p> <p>The geomagnetic <span class="hlt">activity</span> shows the semiannual variation stronger in vernal and autumnal equinoxes than in summer and winter solstices. The semiannual variation has been explained by three main hypotheses such as Axial hypothesis, Equinoctial hypothesis, and Russell-McPherron Effect. Many studies using the various geomagnetic indices have done to support three main hypotheses. In recent, Oh & Yi (2011) examined the <span class="hlt">solar</span> magnetic polarity dependency of the geomagnetic storm occurrence defined by Dst index. They reported that there is no dependency of the semiannual variation on the sign of the <span class="hlt">solar</span> polar fields. This study examines the <span class="hlt">solar</span> magnetic polarity dependency of quiet time geomagnetic <span class="hlt">activity</span>. Using Dxt index (Karinen & Mursula 2005) and Dcx index (Mursula & Karinen 2005) which are recently suggested, in addition to Dst index, we analyze the data of three-year at each <span class="hlt">solar</span> minimum for eight <span class="hlt">solar</span> cycles since 1932. As a result, the geomagnetic <span class="hlt">activity</span> is stronger in the period that the <span class="hlt">solar</span> magnetic polarity is anti-parallel with the Earth's magnetic polarity. There exists the difference between vernal and autumnal equinoxes regarding the <span class="hlt">solar</span> magnetic polarity dependency. However, the difference is not statistically significant. Thus, we conclude that there is no <span class="hlt">solar</span> magnetic polarity dependency of the semiannual variation for quiet time geomagnetic <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960009737&hterms=solar+radiation+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bradiation%2Bpressure','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960009737&hterms=solar+radiation+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsolar%2Bradiation%2Bpressure"><span id="translatedtitle"><span class="hlt">Solar</span> sail attitude control including <span class="hlt">active</span> nutation damping in a fixed-momentum wheel satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Azor, Ruth</p> <p>1992-01-01</p> <p>In geostationary cruise of a momentum biased satellite, it is necessary to stabilize the roll/yaw attitude due to disturbances, caused mainly by <span class="hlt">solar</span> radiation pressure. This work presents a roll/yaw control which is obtained by the use of <span class="hlt">solar</span> arrays and fixed flaps as actuators, with a horizon sensor for roll measurement. The design also includes an <span class="hlt">active</span> nutation damping.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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