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Sample records for 19th solar cycle

  1. Properties of sunspot cycles and hemispheric wings since the 19th century

    NASA Astrophysics Data System (ADS)

    Leussu, Raisa; Usoskin, Ilya G.; Arlt, Rainer; Mursula, Kalevi

    2016-08-01

    Aims: The latitudinal evolution of sunspot emergence over the course of the solar cycle, the so-called butterfly diagram, is a fundamental property of the solar dynamo. Here we present a study of the butterfly diagram of sunspot group occurrence for cycles 7-10 and 11-23 using data from a recently digitized sunspot drawings by Samuel Heinrich Schwabe in 1825-1867, and from RGO/USAF/NOAA(SOON) compilation of sunspot groups in 1874-2015. Methods: We developed a new, robust method of hemispheric wing separation based on an analysis of long gaps in sunspot group occurrence in different latitude bands. The method makes it possible to ascribe each sunspot group to a certain wing (solar cycle and hemisphere), and separate the old and new cycle during their overlap. This allows for an improved study of solar cycles compared to the common way of separating the cycles. Results: We separated each hemispheric wing of the butterfly diagram and analysed them with respect to the number of groups appearing in each wing, their lengths, hemispheric differences, and overlaps. Conclusions: The overlaps of successive wings were found to be systematically longer in the northern hemisphere for cycles 7-10, but in the southern hemisphere for cycles 16-22. The occurrence of sunspot groups depicts a systematic long-term variation between the two hemispheres. During Schwabe time, the hemispheric asymmetry was north-dominated during cycle 9 and south-dominated during cycle 10.

  2. Using sunshine duration data to reconstruct total solar radiation time series since the late 19th century, for Athens area

    NASA Astrophysics Data System (ADS)

    Founda, Dimitra; Kazadzis, Stelios; Pierros, Fragiskos; Mihalopoulos, Nikolaos

    2015-04-01

    Due to the scarcity of surface solar radiation measurements and the lack of long term time series of this variable, sunshine duration (SDu) has been widely considered as a useful proxy for surface total solar radiation (TSR) reaching the earth. Numerous relationships between SDu and TSR have been proposed which vary between sites, as a result of the dependence of the two variables from climatic and astronomical components. At the National Observatory of Athens (NOA), measurements of sunshine duration and surface total solar radiation have been conducted continuously since 1897 and 1953 respectively. These are the longest uninterrupted time series of SDu and TSR in the country. The ability of SDu observations at NOA to serve as a proxy for the estimation of TSR and the detection of its interannual and multi decadal variability is examined in the study. Using the respective time series we have retrieved the relationship between SDu and TSR on a monthly, seasonal and annual basis. To test the retrieved functions we have derived them for the period 1985-2013 and tested them for the period 1953-1984, where synchronous SDu and TSR measurements are available. A strong linear relationship between the time series of monthly SDU and TSR was found. The two series were highly correlated (correlation coefficient > 0.95, p<0.001). On a seasonal basis, stronger correlation between SDu and TSR was detected in winter, autumn and spring, when SDu and TSR exhibit larger variability due to cloudiness. The correlation coefficient was lower in summer, when almost clear sky conditions prevail in Athens. The results showed that SDu observations in Athens can successfully provide quantitative information on shortwave solar radiation, particularly under all-sky conditions. The calculated functions can be used for the reconstruction of TSR back to the late 19th century. This unique 115-yrs SDu and TSR retrieved datasets can provide valuable and unknown information of TSR variability over the

  3. The 19th Project Integration Meeting

    NASA Technical Reports Server (NTRS)

    Mcdonald, R. R.

    1981-01-01

    The Flat-Plate Solar Array Project is described. Project analysis and integration is discussed. Technology research in silicon material, large-area silicon sheet and environmental isolation; cell and module formation; engineering sciences, and module performance and failure analysis. It includes a report on, and copies of visual presentations made at, the 19th Project Integration Meeting held at Pasadena, California, on November 11, 1981.

  4. The Solar Cycle.

    PubMed

    Hathaway, David H

    The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  5. The Solar Cycle

    NASA Astrophysics Data System (ADS)

    Hathaway, David H.

    2015-12-01

    The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  6. Ground-Level Solar Cosmic Ray Data from Solar Cycle 19

    NASA Technical Reports Server (NTRS)

    Shea, M. A.

    2003-01-01

    The purpose of this grant was to locate, catalog, and assemble, in standard computer format, ground-level solar cosmic ray data acquired by cosmic ray detectors for selected events in the 19th solar cycle. The events for which we initially proposed to obtain these data were for the events of 23 February 1956,4 May 1960, 12 and 15 November 1960 and 18 and 20 July 1961. These were the largest events of the 19th solar cycle. However, a severe (more than 50%) reduction in the requested funding, required the work effort be limited to neutron monitor data for the 23 February 1956 event and the three major events in 1960.

  7. Solar Cycle Predictions

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean

    2012-01-01

    Solar cycle predictions are needed to plan long-term space missions; just like weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as you consume the reduced propellant load more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5-20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations how those predictions could be made more accurate in the future will be discussed.

  8. Solar Cycle Prediction.

    PubMed

    Petrovay, Kristóf

    A review of solar cycle prediction methods and their performance is given, including forecasts for cycle 24. The review focuses on those aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is further restricted to the issue of predicting the amplitude (and optionally the epoch) of an upcoming solar maximum no later than right after the start of the given cycle. Prediction methods form three main groups. Precursor methods rely on the value of some measure of solar activity or magnetism at a specified time to predict the amplitude of the following solar maximum. Their implicit assumption is that each numbered solar cycle is a consistent unit in itself, while solar activity seems to consist of a series of much less tightly intercorrelated individual cycles. Extrapolation methods, in contrast, are based on the premise that the physical process giving rise to the sunspot number record is statistically homogeneous, i.e., the mathematical regularities underlying its variations are the same at any point of time and, therefore, it lends itself to analysis and forecasting by time series methods. Finally, instead of an analysis of observational data alone, model based predictions use physically (more or less) consistent dynamo models in their attempts to predict solar activity. In their overall performance during the course of the last few solar cycles, precursor methods have clearly been superior to extrapolation methods. Nevertheless, most precursor methods overpredicted cycle 23, while some extrapolation methods may still be worth further study. Model based forecasts have not yet had a chance to prove their skills. One method that has yielded predictions consistently in the right range during the past few solar cycles is that of K. Schatten et al., whose approach is mainly based on the polar field precursor. The incipient cycle 24 will probably mark the end of the Modern Maximum, with the Sun switching to a state of

  9. An international campaign of the 19th century to determine the solar parallax. The US Naval expedition to the southern hemisphere 1849-1852

    NASA Astrophysics Data System (ADS)

    Schrimpf, Andreas

    2014-04-01

    In 1847 Christian Ludwig Gerling, Marburg (Germany), suggested the solar parallax to be determined by measuring the position of Venus close to its inferior conjunction, especially at the stationary points, from observatories on nearly the same meridian but widely differing in latitude. James M. Gilliss, astronomer at the newly founded U.S. Naval Observatory, enthusiastically adopted this idea and procured a grant for the young astronomical community of the United States for an expedition to Chile. There they were to observe several conjunctions of Venus and oppositions of Mars, while the accompanying measurements were to be taken at the US Naval Observatory in Washington D.C. and the Harvard College Observatory at Cambridge, USA. This expedition was supported by A.V. Humboldt, C.F. Gauß, J.F. Encke, S.C. Walker, A.D. Bache, B. Peirce and others. From 1849 to 1852 not only were astronomical, but also meteorological and magnetic observations and measurements recorded, mainly in Santa Lucia close to Santiago, Chile. By comparing these measurements with those taken simultaneously at other observatories around the world the solar parallax could be calculated, although incomplete data from the corresponding northern observatories threatened the project's success. In retrospect this expedition can be recognized as the foundation of the Chilean astronomy. The first director of the new National Astronomical Observatory of Chile was Dr. C.W. Moesta, a Hessian student of Christian Ludwig Gerling's. The exchange of data between German, American and other astronomers during this expedition was well mediated by J.G. Flügel, consul of the United States of America and representative of the Smithsonian Institution in Europe, who altogether played a major role in nurturing the relationship between the growing scientific community in the U.S. and the well established one in Europe at that time.

  10. Solar 22 years cycle

    NASA Astrophysics Data System (ADS)

    Kotov, Valery A.; Sanchez, Francis M.

    2017-01-01

    Seven observatories performed in 1968-2015 numerous daily measurements of general magnetic field of the Sun seen as a star (of a mean line-of-sight field component of the visible solar hemisphere). The new data 2013-2015 confirmed the recent prediction about saw-edged profile of the mean curve of the Hale's 22 years magnetic cycle and, thus, a hypothesis about its cosmological (partial) origin. This is supported by a special analysis of epochs of extrema of Wolf's sunspot number, demonstrating a remarkable stability, since Galileo's time, of the initial phase of the cycle, which can hardly be explained by dynamo theory exclusively.

  11. Forecast of solar cycle 25

    NASA Astrophysics Data System (ADS)

    Krasotkin, Serge; Shmorgilov, Feodor

    The revised method of equal phase averaging was used to predict the main features of the solar cycle 25. The forecast of Wolf number values was obtained not only for solar cycle maximum but for 16 phases of the cycle. The double-peak structure of the cycle maximum phase is well seen. The problems of the long- and superlong-term forecasts of solar activity are discussed.

  12. Astronomical dating in the 19th century

    NASA Astrophysics Data System (ADS)

    Hilgen, Frederik J.

    2010-01-01

    layering in Holocene peat bogs. He specifically linked the exceptionally wet Atlantic period to the prolonged precession minimum at 33,300 yr ago and further related basic stratigraphic alternations to precession induced climate change in general. Such a linkage was also proposed by Grove Karl Gilbert for cyclic alternations in the marine Cretaceous of North America. Extrapolating sedimentation rates, he arrived at an astronomical duration for part of the Cretaceous that was roughly as long as the final estimate of William Thomson for the age of the Earth. Assuming that orbital parameters directly affect sea level, Karl Mayer-Eymar and Blytt correlated the well known succession of Tertiary stages to precession and eccentricity, respectively. Remarkably, Blytt, like Croll before him, used very long-period cycles in eccentricity to establish and validate his tuning. Understandably these studies in the second half of the 19th century were largely deductive in nature and proved partly incorrect later. Nevertheless, this fascinating period marks a crucial phase in the development of the astronomical theory of the ice ages and climate, and in astronomical dating. It preceded the final inductive phase, which started with the recovery of deep-sea cores in 1947 and led to a spectacular revival of the astronomical theory, by a century. The first half of the 20th century can best be regarded as an intermediate phase, despite the significant progress made in both theoretical aspects and tuning.

  13. Solar Cycle Predictions (Invited Review)

    NASA Astrophysics Data System (ADS)

    Pesnell, W. Dean

    2012-11-01

    Solar cycle predictions are needed to plan long-term space missions, just as weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on low-Earth orbit spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as the reduced propellant load is consumed more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5 - 20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations of how those predictions could be made more accurate in the future are discussed.

  14. Solar Cycle #24 and the Solar Dynamo

    NASA Technical Reports Server (NTRS)

    Pesnell, W. Dean; Schatten, Kenneth

    2007-01-01

    We focus on two solar aspects related to flight dynamics. These are the solar dynamo and long-term solar activity predictions. The nature of the solar dynamo is central to solar activity predictions, and these predictions are important for orbital planning of satellites in low earth orbit (LEO). The reason is that the solar ultraviolet (UV) and extreme ultraviolet (EUV) spectral irradiances inflate the upper atmospheric layers of the Earth, forming the thermosphere and exosphere through which these satellites orbit. Concerning the dynamo, we discuss some recent novel approaches towards its understanding. For solar predictions we concentrate on a solar precursor method, in which the Sun s polar field plays a major role in forecasting the next cycle s activity based upon the Babcock- Leighton dynamo. With a current low value for the Sun s polar field, this method predicts that solar cycle #24 will be one of the lowest in recent times, with smoothed F10.7 radio flux values peaking near 130+ 30 (2 4, in the 2013 timeframe. One may have to consider solar activity as far back as the early 20th century to find a cycle of comparable magnitude. Concomitant effects of low solar activity upon satellites in LEO will need to be considered, such as enhancements in orbital debris. Support for our prediction of a low solar cycle #24 is borne out by the lack of new cycle sunspots at least through the first half of 2007. Usually at the present epoch in the solar cycle (-7+ years after the last solar maximum), for a normal size following cycle, new cycle sunspots would be seen. The lack of their appearance at this time is only consistent with a low cycle #24. Polar field observations of a weak magnitude are consistent with unusual structures seen in the Sun s corona. Polar coronal holes are the hallmarks of the Sun s open field structures. At present, it appears that the polar coronal holes are relatively weak, and there have been many equatorial coronal holes. This appears

  15. Solar Cycle #24 and the Solar Dynamo

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth; Pesnell, W. Dean

    2007-01-01

    We focus on two solar aspects related to flight dynamics. These are the solar dynamo and long-term solar activity predictions. The nature of the solar dynamo is central to solar activity predictions, and these predictions are important for orbital planning of satellites in low earth orbit (LEO). The reason is that the solar ultraviolet (UV) and extreme ultraviolet (EUV) spectral irradiances inflate the upper atmospheric layers of the Earth, forming the thermosphere and exosphere through which these satellites orbit. Concerning the dynamo, we discuss some recent novel approaches towards its understanding. For solar predictions we concentrate on a solar precursor method, in which the Sun's polar field plays a major role in forecasting the next cycle s activity based upon the Babcock-Leighton dynamo. With a current low value for the Sun s polar field, this method predicts that solar cycle #24 will be one of the lowest in recent times, with smoothed F10.7 radio flux values peaking near 130 plus or minus 30 (2 sigma), in the 2013 timeframe. One may have to consider solar activity as far back as the early 20th century to find a cycle of comparable magnitude. Concomitant effects of low solar activity upon satellites in LEO will need to be considered, such as enhancements in orbital debris. Support for our prediction of a low solar cycle #24 is borne out by the lack of new cycle sunspots at least through the first half of 2007. Usually at the present epoch in the solar cycle (approx. 7+ years after the last solar maximum), for a normal size following cycle, new cycle sunspots would be seen. The lack of their appearance at this time is only consistent with a low cycle #24. Polar field observations of a weak magnitude are consistent with unusual structures seen in the Sun s corona. Polar coronal holes are the hallmarks of the Sun's open field structures. At present, it appears that the polar coronal holes are relatively weak, and there have been many equatorial coronal holes

  16. Solar Cycle 24 and the Solar Dynamo

    NASA Astrophysics Data System (ADS)

    Pesnell, W. D.; Schatten, K.

    2007-05-01

    We will discuss the polar field precursor method for solar activity prediction, which predicts cycle 24 will be significantly lower than recent activity cycles, and some new ideas rejuvenating Babcock's shallow surface dynamo. The polar field precursor method is based on Babcock and Leighton's dynamo models wherein the polar field at solar minimum plays a major role in generating the next cycle's toroidal field and sunspots. Thus, by examining the polar fields of the Sun near solar minimum, a forecast for the next cycle's activity is obtained. With the current low value for the Sun's polar fields, this method predicts solar cycle 24 will be one of the lowest in recent times, with smoothed F10.7 radio flux values peaking near 135 ± 35 (2 σ), in the 2012-2013 timeframe (equivalent to smoothed Rz near 80 ± 35 [2 σ]). One may have to consider solar activity as far back as the early 20th century to find a cycle of comparable magnitude. We discuss unusual behavior in the Sun's polar fields that support this prediction. Normally, the solar precursor method is consistent with the geomagnetic precursor method, wherein geomagnetic variations are thought to be a good measure of the Sun's polar field strength. Because of the unusual polar field, the Earth does not appear to be currently bathed in the Sun's extended polar field (the interplanetary field), hence negating the primal cause behind the geomagnetic precursor technique. We also discuss how percolation may support Babcock's original shallow solar dynamo. In this process ephemeral regions from the solar magnetic carpet, guided by shallow surface fields, may collect to form pores and sunspots.

  17. Solar Cycle 24 and the Solar Dynamo

    NASA Technical Reports Server (NTRS)

    Pesnell, W. D.; Schatten, K.

    2007-01-01

    We will discuss the polar field precursor method for solar activity prediction, which predicts cycle 24 will be significantly lower than recent activity cycles, and some new ideas rejuvenating Babcock's shallow surface dynamo. The polar field precursor method is based on Babcock and Leighton's dynamo models wherein the polar field at solar minimum plays a major role in generating the next cycle's toroidal field and sunspots. Thus, by examining the polar fields of the Sun near solar minimum, a forecast for the next cycle's activity is obtained. With the current low value for the Sun's polar fields, this method predicts solar cycle 24 will be one of the lowest in recent times, with smoothed F10.7 radio flux values peaking near 135 plus or minus 35 (2 sigma), in the 2012-2013 timeframe (equivalent to smoothed Rz near 80 plus or minus 35 [2 sigma]). One may have to consider solar activity as far back as the early 20th century to find a cycle of comparable magnitude. We discuss unusual behavior in the Sun's polar fields that support this prediction. Normally, the solar precursor method is consistent with the geomagnetic precursor method, wherein geomagnetic variations are thought to be a good measure of the Sun's polar field strength. Because of the unusual polar field, the Earth does not appear to be currently bathed in the Sun's extended polar field (the interplanetary field), hence negating the primal cause behind the geomagnetic precursor technique. We also discuss how percolation may support Babcock's original shallow solar dynamo. In this process ephemeral regions from the solar magnetic carpet, guided by shallow surface fields, may collect to form pores and sunspots.

  18. Solar Proton Events in Six Solar Cycles

    NASA Astrophysics Data System (ADS)

    Vitaly, Ishkov

    Based on materials the catalogs of solar proton events (SPE) in 1955 ‒ 2010 and list SPE for the current 24 solar cycle (SC) are examined confirmed SPE with E> 10 MeV proton flux in excess of 1 proton cm-2 s ster-1 (pfu) from Švestka and Simon’s (1955 - 1969) and 5 volumes Logachev’s (1970 - 2006) Catalogs of SPE. Historically thus it was formed, that the measurements of the proton fluxes began in the epoch “increased” solar activity (SC 18 ‒ 22), and includes transition period of the solar magnetic fields reconstruction from epoch “increased” to the epoch “lowered” solar activity (22 ‒ 23 SC). In current 24 SC ‒ first SC of the incipient epoch of “lowered” SA ‒ SPE realize under the new conditions, to that of previously not observed. As showed a study of five solar cycles with the reliable measurements of E> 10 MeV proton flux in excess of 1 pfu (1964 - 2013): ‒ a quantity of SPEs remained approximately identical in SC 20, 21, somewhat decreased in the initial solar cycle of the solar magnetic fields reconstruction period (22), but it returned to the same quantity in, the base for the period of reconstruction, SC 23. ‒ Into the first 5 years of the each solar cycle development the rate of the proton generation events noticeably increased in 22 cycles of solar activity and returned to the average in cycles 23 and 24. ‒ Extreme solar flare events are achieved, as a rule, in the solar magnetic fields reconstruction period (August - September 1859; June 1991; October ‒ November 2003.), it is confirmed also for SPE: the extreme fluxes of solar protons (S4) except one (August 1972) were occurred in period of perestroika (SC 22 and 23). This can speak, that inside the epochs SA, when the generation of magnetic field in the convective zone works in the steady-state regime, extreme SPE are improbable. ‒ The largest in the fluxes of protons (S3, S4) occur in the complexes of the active regions flare events, where magnetic field more

  19. Solar corona and prediction of the solar cycle 24 amplitude..

    NASA Astrophysics Data System (ADS)

    Pishkalo, M.

    2012-12-01

    Investigation of the solar cycle amplitude dependence on such quantitative parameters of shape and structure of the solar corona as indexes of photometrical and geometrical flattening and extension of polar coronal rays along the solar limb have been made. Observation of the solar corona during total solar eclipses in solar cycles 11-23 were used. The amplitude of solar cycle 24 was predicted on the basis of the parameters values at the cycle minimum. Solar cycle 24 is expected to be weaker than previous cycle 23. The Wolf number in the cycle maximum will amount to 83-113.

  20. A review of solar proton events during the 22nd solar cycle.

    PubMed

    Smart, D F; Shea, M A

    2002-01-01

    Solar cycle 22 had significant, large fluence, energetic particle events on a scale reminiscent of the 19th solar cycle. Examination of the characteristics of these large events suggests that some of the old concepts of spectral form, intensity-time envelope and energy extrapolations, used to estimate the dose from large events that occurred during previous solar cycles should be re-evaluated. There has also been a dramatic change in perspective regarding the source of solar protons observed in interplanetary space. Very large fluence events are associated with powerful fast interplanetary shocks. The elemental composition and charge state of these events is suggestive of a dominate source in the solar corona and not from a very hot plasma. Furthermore, there is a strong suggestion that the intensity-time profile observed in space is dominated by the connection of the observer to an interplanetary shock source rather than to a unique location near the surface of the sun. These concepts will be examined from the perspective of energetic particles contributing to the dose experienced by an astronaut on an interplanetary space mission.

  1. A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY

    SciTech Connect

    Usoskin, Ilya G.; Mursula, Kalevi; Arlt, Rainer; Kovaltsov, Gennady A.

    2009-08-01

    Because of the lack of reliable sunspot observations, the quality of the sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784-1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18-19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e., the latitudinal distribution of sunspots in the 1790s. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793-1796 unambiguously shows that a new cycle started in 1793, which was lost in the traditional Wolf sunspot series. This finally confirms the existence of the lost cycle that has been proposed earlier, thus resolving an old mystery. This Letter brings the attention of the scientific community to the need of revising the sunspot series in the 18th century. The presence of a new short, asymmetric cycle implies changes and constraints to sunspot cycle statistics, solar activity predictions, and solar dynamo theories, as well as for solar-terrestrial relations.

  2. Women in 19th Century Irish immigration.

    PubMed

    Jackson, P

    1984-01-01

    By the 1950s--100 years after the great famine of 1845-49-- 57% of emigrants from the 26 countries of Ireland were women. In the latter 1/2 of the 19th Century, increasing proportions of women emigrated, until they outnumbered men. For women it was more than a flight from poverty. It was also an escape from an increasingly patriarchal society, whose asymetrical development as a colony curtailed women's social space, even in their traditional role as wife and mother. The famine, which is the single greatest influence forcing emigration, undermined the social fabric of an agrarian society, hastening the process of agricultural transformation. The growth of a new class of Irish a British grazier landlords resulted in a situation of acute land scarcity, encouraging tendencies to cling to one's land holding without dividing it. This, combined with new inheritance practices, gave rise to widespread arranged marriages as a means of land consolidation, and the dowry system. The spontaneous marriage practices of famine days also were replaced by a postponement of marriage. These trends severely reduced the choices exerted by women. The absence of big industrialized cities, which might have absorbed displaced rural populations, removed available options, particularly for women. The system of land monopoly and inheritance revolving around male heads of households reinforced partriarchal relations, within a framework of rigid sexual norms, whose enforcement was easy because the church, which played an important role in the emergence of these values, was a major landowner in itself. The subordinated, invisible status of women in post-famine Ireland, and growing barriers to easy access to marriage partners, to waged employment and self-expression, all helped ensure the higher and higher emigration rates of women. The economic transformation of Irish agriculture accelerated the establishment of oppressive values and helped depreciate the position of women to a very low level. The

  3. A Synthesis of Solar Cycle Prediction Techniques

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Wilson, Robert M.; Reichmann, Edwin J.

    1999-01-01

    A number of techniques currently in use for predicting solar activity on a solar cycle timescale are tested with historical data. Some techniques, e.g., regression and curve fitting, work well as solar activity approaches maximum and provide a month-by-month description of future activity, while others, e.g., geomagnetic precursors, work well near solar minimum but only provide an estimate of the amplitude of the cycle. A synthesis of different techniques is shown to provide a more accurate and useful forecast of solar cycle activity levels. A combination of two uncorrelated geomagnetic precursor techniques provides a more accurate prediction for the amplitude of a solar activity cycle at a time well before activity minimum. This combined precursor method gives a smoothed sunspot number maximum of 154 plus or minus 21 at the 95% level of confidence for the next cycle maximum. A mathematical function dependent on the time of cycle initiation and the cycle amplitude is used to describe the level of solar activity month by month for the next cycle. As the time of cycle maximum approaches a better estimate of the cycle activity is obtained by including the fit between previous activity levels and this function. This Combined Solar Cycle Activity Forecast gives, as of January 1999, a smoothed sunspot maximum of 146 plus or minus 20 at the 95% level of confidence for the next cycle maximum.

  4. Solar Cycle Variability in Tropical Column Ozone

    NASA Astrophysics Data System (ADS)

    Yung, Y. L.; Liang, M.; Li, K.; Jiang, X.; Camp, C. D.

    2011-12-01

    Using an empirical orthogonal function (EOF) method [Camp et al., 2003], we analyzed the Merged Ozone Data (MOD) set from late 1978 to the present. The decadal variability of column ozone in the tropics follows that of the sun over three solar cycles. The peak-to-peak amplitude is about 10 DU (Dobson Units), consistent with the conclusion of Camp et al. [2003], who analyzed the MOD data up to and including 2000. Previous attempts to model the amplitude of the observed solar cycle in ozone were unsuccessful, as models tended to underestimate the solar cycle effect. Using the Whole Atmosphere Community Climate Model (WACCM) in combination with the latest satellite measurements of solar variability in the UV [McClintock et al., 2005; Harder et al., 2009], we correctly simulate the solar cycle signal in the total column ozone for the first time. The implications for solar forcing on middle atmosphere chemistry are discussed.

  5. Solar activity cycle - History and predictions

    SciTech Connect

    Withbroe, G.L. )

    1989-12-01

    The solar output of short-wavelength radiation, solar wind, and energetic particles depends strongly on the solar cycle. These energy outputs from the sun control conditions in the interplanetary medium and in the terrestrial magnetosphere and upper atmosphere. Consequently, there is substantial interest in the behavior of the solar cycle and its effects. This review briefly discusses historical data on the solar cycle and methods for predicting its further behavior, particularly for the current cycle, which shows signs that it will have moderate to exceptionally high levels of activity. During the next few years, the solar flux of short-wavelength radiation and particles will be more intense than normal, and spacecraft in low earth orbit will reenter earlier than usual. 46 refs.

  6. Predicting Solar Cycle 24 and beyond

    NASA Astrophysics Data System (ADS)

    Clilverd, Mark A.; Clarke, Ellen; Ulich, Thomas; Rishbeth, Henry; Jarvis, Martin J.

    2006-09-01

    We use a model for sunspot number using low-frequency solar oscillations, with periods 22, 53, 88, 106, 213, and 420 years modulating the 11-year Schwabe cycle, to predict the peak sunspot number of cycle 24 and for future cycles, including the period around 2100 A.D. We extend the earlier work of Damon and Jirikowic (1992) by adding a further long-period component of 420 years. Typically, the standard deviation between the model and the peak sunspot number in each solar cycle from 1750 to 1970 is +/-34. The peak sunspot prediction for cycles 21, 22, and 23 agree with the observed sunspot activity levels within the error estimate. Our peak sunspot prediction for cycle 24 is significantly smaller than cycle 23, with peak sunspot numbers predicted to be 42 +/- 34. These predictions suggest that a period of quiet solar activity is expected, lasting until ~2030, with less disruption to satellite orbits, satellite lifetimes, and power distribution grids and lower risk of spacecraft failures and radiation dose to astronauts. Our model also predicts a recovery during the middle of the century to more typical solar activity cycles with peak sunspot numbers around 120. Eventually, the superposition of the minimum phase of the 105- and 420-year cycles just after 2100 leads to another period of significantly quieter solar conditions. This lends some support to the prediction of low solar activity in 2100 made by Clilverd et al. (2003).

  7. [Earth magnetism research in the 19th century].

    PubMed

    Schröder, W; Wiederkehr, K H

    2000-01-01

    Even before the discovery of the electromagnetism by Oersted, and before Ampère, who attributed all magnetism to the flux of electrical currents, A. v. Humboldt and Hansteen had turned to geomagnetism. With the help of the "Göttinger Magnetische Verein", a worldwide cooperation under the leadership of Gauss game into existence. Even today, Gauss' theory of the geomagnetism is one of the pillars for geomagnetical research work. Thereafter, J. v. Lamont, Prof. in Munich, took over the leadership in Germany. In England, the Magnetic Crusade was started by the initiative of John Herschel and E. Sabine. At the beginning of the forties, James Clarke Ross advanced to the Antarctic Continent, which was then quite unknown. Ten years later, Sabine was able to gather solar-terrestrial relations from the data of the colonical observatories. In the eighties, Arthur Schuster, following Balfour Stewart's ideas, succeeded in interpreting the daily variations of the electrical process in the high atmosphere. The geomagnetic research work in Germany was given a fresh impetus by the First Polar Year 1882-1883. Georg Neumayer, director of the "Deutsche Seewarte" in Hamburg, had been one of the initiators of the Polar Year. He had a close cooperation with the newly founded "Kaiserliches Marineobservatorium" in Wilhelmshaven, and he also managed to gain the collaboration of the "Gauss-Observatorium für Erdmagnetismus" in Göttingen under E. Schering. In the Polar Year, the first automatic recording magnetometers (Kew-Model) were used in a German observatory in Wilhelmshaven. Here M. Eschenhagen, who later became director of the geomagnetic section in the new Meterological-Magnetic Observatory in Potsdam, gained special merit. The treatise considers preceding hypotheses of geomagnetism as well as the palaeomagnetic studies. The essential seismological investigations at the turn of the 19th to the 20th century are briefly treated. They represent one of the keystones for the modern

  8. 11-year cycle solar modulation of cosmic ray intensity inferred from C-14 content variation in dated tree rings

    NASA Technical Reports Server (NTRS)

    Fan, C. Y.; Chen, T. M.; Yun, S. X.; Dai, K. M.

    1983-01-01

    A liquid scintillation-photomultiplier tube counter system was used to measure the Delta-C-14 values of 60 tree rings, dating from 1866 to 1925, that were taken from a white spruce grown in Canada at 68 deg N, 130 deg W. A 10-percent variation is found which is anticorrelated with sunspot numbers, although the amplitude of the variation is 2-3 times higher than expected in trees grown at lower latitudes. A large dip in the data at about 1875 suggests an anomalously large modulation of cosmic ray intensity during the 1867-1878 AD solar cycle, which was the most active of the 19th century.

  9. Solar cycle 24 from the standpoint of solar paleoastrophysics

    NASA Astrophysics Data System (ADS)

    Ogurtsov, M. G.

    2016-03-01

    The predictions of the maximum yearly mean sunspot number in the current cycle 24 made by means of the astrophysical approach (by analyzing the instrumental data on solar activity and using various dynamo models) and the paleoastrophysical approach (by analyzing the paleoreconstructions of solar activity spanning the interval from 8555 BC to 1605 AD) are compared. The paleoastrophysical predictions are shown to be considerably more accurate. The amplitude of the next cycle 25 is predicted. It is shown that from the standpoint of solar paleoastrophysics, cycle 25 will most likely be of medium power, R max(25) = 85.0 ± 30.5.

  10. Proceedings of the 19th Space Photovoltaic Research and Technology Conference

    NASA Technical Reports Server (NTRS)

    Castro, Stephanie (Compiler); Morton, Thomas (Compiler)

    2007-01-01

    The 19th Space Photovoltaic Research and Technology Conference (SPRAT XIX) was held September 20 to 22, 2005, at the Ohio Aerospace Institute (OAI) in Brook Park, Ohio. The SPRAT Conference, hosted by the Photovoltaic and Space Environments Branch of the NASA Glenn Research Center, brought together representatives of the space photovoltaic community from around the world to share the latest advances in space solar cell technology. This year's conference continued to build on many of the trends shown in SPRAT XVIII-the continued advances of thin-film and multijunction solar cell technologies and the new issues required to qualify those types of cells for space applications.

  11. A Decline in Solar Cycle Strength

    NASA Astrophysics Data System (ADS)

    Chapman, G. A.; de Toma, G.; Cookson, A.

    2013-12-01

    The strength of solar activity appears to be in decline over the past three solar cycles. The decline is seen in sunspot area, facular/network area and the sunspot number. In addition, cycle 24 has been unusual in that many, if not most, of the bipolar sunspot groups have had only a leader spot with no follower spot. This research was partially supported by grants from NSF and NASA. Corrected spot area from CFDT1 at the San Fernando Observatory

  12. Solar proton events during solar cycles 19, 20, and 21

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Armstrong, T. P.; Dao-Gibner, L.; Silverman, S.

    1990-01-01

    Earlier studies based on a single solar cycle had resulted in a sharp division of events into 'ordinary' and 'anomalously large' events. Two such entirely separate distributions imply two entirely separate acceleration mechanisms, one common and the other very rare. The sharp division is neither required nor justified by this larger sample. Instead the event intensity forms a smooth distribution for intensities up to the largest observed implying that any second acceleration mechanism cannot be rare. Also, a clear bimodal variation of annual integrated flux with solar cycle phase but no statistically significant tendency for the large events to avoid sunspot maximum is found. There is almost no relation between the maximum sunspot number in a solar cycle and the solar cycle integrated flux. It is also found that for annual sunspot numbers greater than 35 there is no relation whatsoever between the annual sunspot numbers and annual integrated flux.

  13. Changes of solar extreme ultraviolet spectrum in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Huang, Jianping; Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo

    2016-07-01

    Following the extreme solar minimum during 2008-2009, solar activity keeps low in solar cycle 24 (SC24) and is making SC24 the weakest one of recent cycles. In this paper, using observations from Earth-orbiting satellites, we compare the solar extreme ultraviolet (EUV) irradiance between SC23 and SC24 and investigate the solar cycle change of linear dependence of EUV on the P ((F10.7 + F10.7A)/2) and Mg II core-to-wing ratio indices. The Bremen composite Mg II index is strongly correlated with P over the two solar cycles, while this is not the case for the Laboratory for Atmospheric and Space Physics (LASP) composite Mg II index, so we focus on the different dependence of EUV on the P and LASP Mg II indices. As a result we find that three coronal emissions (Fe XV at 28.4 nm and 41.7 nm and Fe XVI at 33.5 nm) brighten in SC24 relative to P; i.e., the magnitude of irradiance is higher than in SC23 at the same level of P. But relative to the LASP Mg II index, these emissions show no appreciable solar cycle differences. By contrast, the H I Lyman α at 121.6 nm dims in SC24 relative to the LASP Mg II but shows identical dependence on P in the two solar cycles. This result seems to contradict a well-accepted fact that chromospheric and transition region emissions are better represented by the Mg II index and coronal lines by F10.7. For the different solar cycle variability of EUV in SC24, whether it is caused by source changes on the Sun is still unclear, but we suggest that it needs to be considered in proxy modeling of the EUV irradiance and aeronomic studies.

  14. Activity of the northern and southern hemispheres as a basis of the solar cycle manifestation

    NASA Astrophysics Data System (ADS)

    Ryabov, M. I.

    2015-12-01

    The dynamics of the evolution of solar cycles is considered a result of the activity manifestation in the northern and southern hemispheres. A study was performed based on separate datasets for the northern and southern hemispheres that contain the monthly and daily averages of the areas of sunspot groups for the period covering activity cycles from 12 to 24 (1874-2013) and the daily values of the Wolf number in the northern and southern hemispheres during cycles 23-24 (1992-2013).To obtain a pattern of development of the "northern" and "southern" solar cycles in detail, a special technique for the extended application of the wavelet analysis has been developed. It allows different the wave processes forming a solar cycle to be distinguished, together with the time of their existence. The application of bandpass Fourier filtering to the obtained data shows that the length of "11-year" cycles by the index S p varies from 10.2 to 11.5 years in the northern hemisphere and from 9.7 to 13.2 years in the southern. The 19th "northern" and 18th "southern" cycles turned out to be maximal. The formation of each of the cycles by all activity indices is determined by the joint effect of long-period processes lasting from 3 to 7 years and short-period processes lasting less than 2 years. When moving from one cycle to another, the long-period processes demonstrate mergings, separations, modulation, and periodic decays. The abnormal activity that appears during the growth, maximum, or decay phase of a cycle is formed at the expense of the simultaneous strengthening of short-period processes, the lengths and "period spectra" of which noticeably differ in the northern and southern hemispheres.

  15. Technical improvements in 19th century Belgian window glass production

    NASA Astrophysics Data System (ADS)

    Lauriks, Leen; Collette, Quentin; Wouters, Ine; Belis, Jan

    Glass was used since the Roman age in the building envelope, but it became widely applied together with iron since the 19th century. Belgium was a major producer of window glass during the nineteenth century and the majority of the produced window glass was exported all over the world. Investigating the literature on the development of 19th century Belgian window glass production is therefore internationally relevant. In the 17th century, wood was replaced as a fuel by coal. In the 19th century, the regenerative tank furnace applied gas as a fuel in a continuous glass production process. The advantages were a clean production, a more constant and higher temperature in the furnace and a fuel saving. The French chemist Nicolas Leblanc (1787-1793) and later the Belgian chemist Ernest Solvay (1863) invented processes to produce alkali out of common salt. The artificial soda ash improved the quality and aesthetics of the glass plates. During the 19th century, the glass production was industrialized, influencing the operation of furnaces, the improvement of raw materials as well as the applied energy sources. Although the production process was industrialized, glassblowing was still the work of an individual. By improving his work tools, he was able to create larger glass plates. The developments in the annealing process followed this evolution. The industry had to wait until the invention of the drawn glass in the beginning of the 20th century to fully industrialise the window glass manufacture process.

  16. Vocational Education in the 19th Century American Academy.

    ERIC Educational Resources Information Center

    Law, Gordon F.

    The phrase "all things useful and all things ornamental," coined by Benjamin Franklin, describes the stated mission of most of the approximately 6,000 educational academies flourishing in America in the mid-19th century. Built upon the roots of Latin grammar schools, the academies evolved to include courses in many areas, from classical…

  17. Woman Suffrage and the 19th Amendment. Teaching with Documents.

    ERIC Educational Resources Information Center

    National Archives and Records Administration, Washington, DC.

    Beginning in the mid-19th century, several generations of woman suffrage supporters lectured, wrote, marched, lobbied, and practiced civil disobedience to achieve what many people considered a radical change in the U.S. Constitution. Militant suffragists used tactics such as parades, silent vigils, and hunger strikes. In 1870 the 15th amendment to…

  18. 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.

  19. Missing solar cycle hypothesis and basic statistical regularities of solar cycles

    NASA Astrophysics Data System (ADS)

    Ogurtsov, M. G.

    2012-12-01

    The basic statistical properties of solar cycles, including the Gnevyshev-Ol' rule, the Waldmeier effect, and the amplitude-period effect, are tested using data on the number of sunspot groups for 1700-1996, considering the hypothesis about a missing solar cycle in the late 18th century. The results show that the division of the long cycle of 1784-1800 into two short cycles—1784-1793 and 1793-1800—alters significantly the pattern of the solar cycles. The Gnevyshev-Ol' cycle intensity effect becomes stronger, and almost all other statistical effects grow weaker. This change is due to the fact that the short and weak cycle of 1793-1800 is statistically very unusual and its features are very different from those of other solar cycles.

  20. Magnetic network elements in solar cycle 23

    NASA Astrophysics Data System (ADS)

    Jin, Chunlan; Wang, Jingxiu

    2013-07-01

    In this report, we present our recent effort to understand the cyclic behavior of network magnetic elements based on the unique database from full-disk observations provided by Michelson Doppler Imager on board the Solar and Heliospheric Observatory in the interval including the entire cycle 23. The following results are unclosed. (1) The quiet regions dominate the solar magnetic flux for about 8 years in solar cycle 23, and from the solar minimum to maximum they contribute (0.94-1.44)×1023Mx flux to the solar photosphere. In the entire cycle 23, the magnetic flux of the quiet regions is 1.12 times that of active regions. The occupation ratio of quiet region flux equally characterizes the course of a solar cycle. (2) With the increasing magnetic flux per element, the variations of numbers and total flux of the network elements show three-fold scenario: no-correlation, anti-correlation, and correlation with sunspots, respectively. The anti-correlated elements covering the range of (3-32)×1018Mx occupy 77% of total element number and 37% of quiet Sun flux. (3) The time-latitude distribution of anti-correlated magnetic elements is out of phase with that of sunspots, while the correlated elements display the similar butterfly diagram of sunspots but with wider latitude distribution. These results imply that the correlated elements are the debris of decayed sunspots, and the source of anti-correlated elements is modulated by sunspot magnetic field.

  1. Examination of Solar Cycle Statistical Model and New Prediction of Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Wilson, John W.

    2000-01-01

    Sunspot numbers in the current solar cycle 23 were estimated by using a statistical model with the accumulating cycle sunspot data based on the odd-even behavior of historical sunspot cycles from 1 to 22. Since cycle 23 has progressed and the accurate solar minimum occurrence has been defined, the statistical model is validated by comparing the previous prediction with the new measured sunspot number; the improved sunspot projection in short range of future time is made accordingly. The current cycle is expected to have a moderate level of activity. Errors of this model are shown to be self-correcting as cycle observations become available.

  2. Solar cycle modulation of Southern Annular Mode

    NASA Astrophysics Data System (ADS)

    Kuroda, Yuhji

    2016-04-01

    Climate is known to be affected by various factors, including oceanic changes and volcanic eruptions. 11-year solar cycle change is one of such important factors. Observational analysis shows that the winter-mean North Atlantic Oscillation (NAO) and late-winter/spring Southern Annular Mode (SAM) show structural modulation associated with 11-year solar cycle. In fact, these signals tend to extend from surface to upper stratosphere and persistent longer period only in the High Solar (HS) years. In the present study, we used 35-year record of ERA-Interim reanalysis data and performed wave-energy and momentum analysis on the solar-cycle modulation of the SAM to examine key factors to create such solar-SAM relationship. It is found that enhanced wave-mean flow interaction tends to take place in the middle stratosphere in association with enhanced energy input from diabatic heating on September only in HS years. The result suggests atmospheric and solar conditions on September are keys to create solar-SAM relationship.

  3. Solar Observations In Cycle 4 Of ALMA

    NASA Astrophysics Data System (ADS)

    Shimojo, Masumi; ALMA Solar Development Team

    2016-07-01

    The Sun is one of scientific targets of the Atacama Large Millimeter/sub-millimeter Array (ALMA). However, solar observations had not been offered until Cycle 3, because of a lot of difficulties for observing the Sun with the radio interferometer for night astronomy. We have been developing observing schemes for the Sun since 2010, and the joint ALMA observatory started to offer solar observations from Cycle 4 at last. Since the special treatments are needed for solar observations, there are some limitations for observing the Sun in comparison with the observations of other celestial targets. We held the commissioning campaign in December 2015 for verifying the observing modes, and the images synthesized from the commissioning data show us new sights of solar physics. The data obtained with the ALMA will bring about great scientific achievements.

  4. Solar Cycles - to Updating Basic Parameters

    NASA Astrophysics Data System (ADS)

    Ryabov, M. I.

    Examining daily and monthly averages of solar activity index of the northern and southern hemispheres on the total area of spots-Sp (12-24 cycles, 1874-2014), the Wolf numbers-W (22-24 cycles, 1992-2014). Application of band pass filtering based on Wavelet analysis shows that 'Northern' and 'Southern' cycles have their own start time, rise phase, the phases of decline, maximum and minimum. The formation of each cycle on all indices of activity is determined as a result of the combined effect of the long-period and shortperiodic processes.

  5. Solar Spectral Irradiance Changes During Cycle 24

    NASA Technical Reports Server (NTRS)

    Marchenko, Sergey; Deland, Matthew

    2014-01-01

    We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by approximately 0.6% +/- 0.2% around 265 nm. These changes gradually diminish to 0.15% +/- 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar "continuum." Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar "continuum," the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at lambda approximately or greater than 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.

  6. On Solar Cycle Predictions and Reconstructions

    DTIC Science & Technology

    2008-12-01

    for grand solar minima and to reconstruct the relative sunspol number in the Maunder minimum . Methods. We calculate the asymmetry of the ascending...was identified in the asymmetry data. The maximal smoothed monthly sunspot number during the Maunder minimum was reconstructed and found to be in the...cycle, to investigate proxies for grand solar minima and to reconstruct the relative sunspot number in the Maunder minimum . Methods. We calculate the

  7. [Popular knowledge about medicaments in 19th century periodicals].

    PubMed

    Arabas, Iwona

    2004-01-01

    Polish periodicals published since the beginning of 19th century contained household knowledge which was of great importance to peasants. In the second half of 19th century the number of articles related to prevention, treatment as well as life hygiene (including nutrition guidance) enlarged significantly. The term "household medicine box# was very often used in periodicals as titles of both: sections dedicated to hygiene or medicine as well as for articles describing medicaments intended to be kept in the boxes. Articles referenced law regulations stated in "law for pharmacists and pharmacies# from 1844. The availability of medical handbooks widened with the end of the century and this fact may have caused the changes in profiles of numerous medical sections in popular periodicals. However the changes did not affect publications related to contents of medical boxes.

  8. Prediction Methods in Solar Sunspots Cycles

    PubMed Central

    Ng, Kim Kwee

    2016-01-01

    An understanding of the Ohl’s Precursor Method, which is used to predict the upcoming sunspots activity, is presented by employing a simplified movable divided-blocks diagram. Using a new approach, the total number of sunspots in a solar cycle and the maximum averaged monthly sunspots number Rz(max) are both shown to be statistically related to the geomagnetic activity index in the prior solar cycle. The correlation factors are significant and they are respectively found to be 0.91 ± 0.13 and 0.85 ± 0.17. The projected result is consistent with the current observation of solar cycle 24 which appears to have attained at least Rz(max) at 78.7 ± 11.7 in March 2014. Moreover, in a statistical study of the time-delayed solar events, the average time between the peak in the monthly geomagnetic index and the peak in the monthly sunspots numbers in the succeeding ascending phase of the sunspot activity is found to be 57.6 ± 3.1 months. The statistically determined time-delayed interval confirms earlier observational results by others that the Sun’s electromagnetic dipole is moving toward the Sun’s Equator during a solar cycle. PMID:26868269

  9. THE BIMODAL STRUCTURE OF THE SOLAR CYCLE

    SciTech Connect

    Du, Z. L.

    2015-05-01

    Some properties of the 11 yr solar cycle can be explained by the current solar dynamo models. However, some other features remain not well understood such as the asymmetry of the cycle, the double-peaked structure, and the “Waldmeier effect” that a stronger cycle tends to have less rise time and a shorter cycle length. We speculate that the solar cycle is governed by a bi-dynamo model forming two stochastic processes depicted by a bimodal Gaussian function with a time gap of about 2 yr, from which the above features can be reasonably explained. The first one describes the main properties of the cycle dominated by the current solar dynamo models, and the second one occurs either in the rising phase as a short weak explosive perturbation or in the declining phase as a long stochastic perturbation. The above function is the best one selected from several in terms of the Akaike information criterion. Through analyzing different distributions, one might speculate about the dominant physical process inside the convection zone. The secondary (main) process is found to be closely associated with complicated (simple) active ranges. In effect, the bi-dynamo model is a reduced form of a multi-dynamo model, which could occur from the base of the convection zone through its envelope and from low to high heliographic latitude, reflecting the active belts in the convection zone. These results are insensitive to the hemispheric asymmetry, smoothing filters, and distribution functions selected and are expected to be helpful in understanding the formation of solar and stellar cycles.

  10. Solar Cycle Variation of CMEs and CIRs

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.

    2011-01-01

    Coronal mass ejections (CMEs) and high-speed solar wind streams (HSS) are two solar phenomena that produce large-scale structures in the interplanetary (IP) medium. CMEs evolve into interplanetary CMEs (ICMEs) and the HSS result in corotating interaction regions (CIRs) when they interact with preceding slow solar wind. CMEs and CIRs originate from closed (active region and filament region) and open (corona) hole) magnetic field regions on the Sun, respectively. These two types of mass emissions from the Sun are responsible for the largest effects on the heliosphere, particularly on Earth's space environment. This paper discussed how these structures and their solar sources vary with the solar cycle and the consequent changes in the geospace impact.

  11. Solar cycle changes in the polar solar wind

    NASA Technical Reports Server (NTRS)

    Coles, W. A.; Rickett, B. J.; Rumsey, V. H.; Kaufman, J. J.; Turley, D. G.; Ananthakrishnan, S.; Armstrong, J. W.; Harmons, J. K.; Scott, S. L.; Sime, D. G.

    1980-01-01

    It is noted that although the 11 year solar cycle was first recognized in 1843, it is still only poorly understood. Further, while there are satisfactory models for the magnetic variations, the underlying physics is still obscure. New observations on the changing three-dimensional form of the solar wind are presented which help relate some of the modulations observed in geomagnetic activity, the ionosphere, and the flux of galactic cosmic rays.

  12. Changes of solar extreme ultraviolet spectrum in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Hao, Yongqiang; Zhang, Donghe; Xiao, Zuo; Huang, Jianping

    2016-07-01

    Following the extreme solar minimum during 2008 - 2009, solar activity keeps low in solar cycle 24 (SC24) and is making SC24 the weakest one of recent cycles. In this paper, we compare the solar EUV spectral irradiance between SC23 and SC24, using the measurements by the Solar EUV Experiment (SEE) on the Thermospheric Ionospheric Mesospheric Energy and Dynamics (TIMED) spacecraft. The EUV spectrum varies with solar activity, and is in general a linear function of a proxy index P= (F10.7 + F10.7A)/2. However, we find the slope of this function, i.e., the change rate of irradiance at each wavelength with P, differs between SC23 and SC24. Consequently, at a given P level, the irradiance in SC24 is higher at wavelength of 30 - 50 nm, but lower at 60 - 120 nm and longward of 140 nm; the inter-cycle variation of EUV irradiance at some wavelengths can be 30 - 40% in absolute flux. We further examine 38 most intense emission lines and find that, taking P as a reference, most of the bright coronal lines get stronger in SC24 and, by contrast, those from the chromosphere and transition region have less variability in SC24. We therefore suggest that, the empirical relation between solar EUV and P, which is derived from observations in previous solar cycles, may not adapt to SC24. The changes in EUV spectrum need to be considered in the models for aeronomic study, especially those using F10.7 index as an input parameter.

  13. 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

  14. Sources of solar wind over the solar activity cycle

    PubMed Central

    Poletto, Giannina

    2012-01-01

    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

  15. 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.

  16. The solar UV related changes in total ozone from a solar rotation to a solar cycle

    SciTech Connect

    Chandra, S.

    1991-05-01

    The Nimbus-7 TOMS version 6 data, corrected for the instrument degradation, are analyzed to delineate the solar UV related changes in total ozone (TOZ) against background signals of dynamical origin. It is shown that the solar UV related change in TOZ over a solar cycle is about 1.5 percent that may be attributed to about 6 percent change in the solar UV flux near 200 nm. This estimate is also consistent with the solar UV related changes in TOZ over a time scale of a solar rotation. In the solar rotation case, ozone lags the solar UV by 3-4 days and its sensitivity to solar UV change is a factor of 203 less than for the solar cycle case. Both these effects are attributed to chemical time constants in the lower stratosphere that are comparable to the period of a solar rotation.

  17. The solar UV related changes in total ozone from a solar rotation to a solar cycle

    NASA Technical Reports Server (NTRS)

    Chandra, S.

    1991-01-01

    The Nimbus-7 TOMS version 6 data, corrected for the instrument degradation, are analyzed to delineate the solar UV related changes in total ozone (TOZ) against background signals of dynamical origin. It is shown that the solar UV related change in TOZ over a solar cycle is about 1.5 percent that may be attributed to about 6 percent change in the solar UV flux near 200 nm. This estimate is also consistent with the solar UV related changes in TOZ over a time scale of a solar rotation. In the solar rotation case, ozone lags the solar UV by 3-4 days and its sensitivity to solar UV change is a factor of 2-3 less than for the solar cycle case. Both these effects are attributed to chemical time constants in the lower stratosphere that are comparable to the period of a solar rotation.

  18. Study of the Solar Cycle from Space

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The objectives of and benefits to be derived from a program of solar cycle research are discussed with emphasis on the role space observations will play in this venture. The strategy to be employed in the coming decade is considered as well as crucial missions, experiments, and the theoretical advances required.

  19. Solar Cycle 23 in Coronal Bright Points

    NASA Astrophysics Data System (ADS)

    Sattarov, Isroil; Pevtsov, Alexei A.; Karachik, Nina V.; Sherdanov, Chori T.; Tillaboev, A. M.

    2010-04-01

    We describe an automatic routine to identify coronal bright points (CBPs) and apply this routine to SOHO/EIT observations taken in the 195 Å spectral range during solar cycle 23. We examine the total number of CBPs and its change in the course of this solar cycle. Unlike some other recent studies, we do find a modest ≈30% decrease in the number of CBPs associated with maximum of sunspot activity. Using the maximum brightness of CBPs as a criterion, we separate them on two categories: dim CBPs, associated with areas of a quiet Sun, and bright CBPs, associated with an active Sun. We find that the number of dim coronal bright points decreases at the maximum of sunspot cycle, while the number of bright CBPs increases. The latitudinal distributions suggest that dim CBPs are distributed uniformly over the solar disk. Active Sun CBPs exhibit a well-defined two-hump latitudinal profile suggestive of enhanced production of this type of CBPs in sunspot activity belts. Finally, we investigate the relative role of two mechanisms in cycle variations of CBP number, and conclude that a change in fraction of solar surface occupied by the quiet Sun’s magnetic field is the primary cause, with the visibility effect playing a secondary role.

  20. Geomagnetism during solar cycle 23: Characteristics.

    PubMed

    Zerbo, Jean-Louis; Amory-Mazaudier, Christine; Ouattara, Frédéric

    2013-05-01

    On the basis of more than 48 years of morphological analysis of yearly and monthly values of the sunspot number, the aa index, the solar wind speed and interplanetary magnetic field, we point out the particularities of geomagnetic activity during the period 1996-2009. We especially investigate the last cycle 23 and the long minimum which followed it. During this period, the lowest values of the yearly averaged IMF (3 nT) and yearly averaged solar wind speed (364 km/s) are recorded in 1996, and 2009 respectively. The year 2003 shows itself particular by recording the highest value of the averaged solar wind (568 km/s), associated to the highest value of the yearly averaged aa index (37 nT). We also find that observations during the year 2003 seem to be related to several coronal holes which are known to generate high-speed wind stream. From the long time (more than one century) study of solar variability, the present period is similar to the beginning of twentieth century. We especially present the morphological features of solar cycle 23 which is followed by a deep solar minimum.

  1. Geomagnetism during solar cycle 23: Characteristics

    PubMed Central

    Zerbo, Jean-Louis; Amory-Mazaudier, Christine; Ouattara, Frédéric

    2012-01-01

    On the basis of more than 48 years of morphological analysis of yearly and monthly values of the sunspot number, the aa index, the solar wind speed and interplanetary magnetic field, we point out the particularities of geomagnetic activity during the period 1996–2009. We especially investigate the last cycle 23 and the long minimum which followed it. During this period, the lowest values of the yearly averaged IMF (3 nT) and yearly averaged solar wind speed (364 km/s) are recorded in 1996, and 2009 respectively. The year 2003 shows itself particular by recording the highest value of the averaged solar wind (568 km/s), associated to the highest value of the yearly averaged aa index (37 nT). We also find that observations during the year 2003 seem to be related to several coronal holes which are known to generate high-speed wind stream. From the long time (more than one century) study of solar variability, the present period is similar to the beginning of twentieth century. We especially present the morphological features of solar cycle 23 which is followed by a deep solar minimum. PMID:25685427

  2. 19th JANNAF Safety and Environmental Protection Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Cocchiaro, J. E. (Editor); Becker, D. L. (Editor)

    2002-01-01

    This volume, the first of two volumes, is a compilation of 22 unclassified/unlimited technical papers presented at the 19th Joint Army-Navy-NASA-Air Force (JANNAF) Safety & Environmental Protection Subcommittee Meeting. The meeting was held 18-21 March 2002 at the Sheraton Colorado Springs Hotel, Colorado Springs, Colorado. Topics covered include green energetic materials and life cycle pollution prevention; space launch range safety; propellant/munitions demilitarization, recycling, and reuse: and environmental and occupational health aspects of propellants and energetic materials.

  3. 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

  4. Properties of solar activity and ionosphere for solar cycle 25

    NASA Astrophysics Data System (ADS)

    Deminov, M. G.; Nepomnyashchaya, E. V.; Obridko, V. N.

    2016-11-01

    Based on the known forecast of solar cycle 25 amplitude ( Rz max ≈ 50), the first assessments of the shape and amplitude of this cycle in the index of solar activity F10.7 (the magnitude of solar radio flux at the 10.7 cm wavelength) are given. It has been found that ( F10.7)max ≈ 115, which means that it is the lowest solar cycle ever encountered in the history of regular ionospheric measurements. For this reason, many ionospheric parameters for cycle 25, including the F2-layer peak height and critical frequency ( hmF2 and foF2), will be extremely low. For example, at middle latitudes, typical foF2 values will not exceed 8-10 MHz, which makes ionospheric heating ineffective in the area of upper hybrid resonance at frequencies higher than 10 MHz. The density of the atmosphere will also be extremely low, which significantly extends the lifetime of low-orbit satellites. The probability of F-spread will be increased, especially during night hours.

  5. If We Can't Predict Solar Cycle 24, What About Solar Cycle 34?

    NASA Technical Reports Server (NTRS)

    Pesnell. William Dean

    2008-01-01

    Predictions of solar activity in Solar Cycle 24 range from 50% larger than SC 23 to the onset of a Grand Minimum. Because low levels of solar activity are associated with global cooling in paleoclimate and isotopic records, anticipating these extremes is required in any longterm extrapolation of climate variability. Climate models often look forward 100 or more years, which would mean 10 solar cycles into the future. Predictions of solar activity are derived from a number of methods, most of which, such as climatology and physics-based models, will be familiar to atmospheric scientists. More than 50 predictions of the maximum amplitude of SC 24 published before solar minimum will be discussed. Descriptions of several methods that result in the extreme predictions and some anticipation of even longer term predictions will be presented.

  6. Study of solar activity and cosmic ray modulation during solar cycle 24 in comparison to previous solar cycle

    NASA Astrophysics Data System (ADS)

    Mishra, V. K.; Mishra, A. P.

    2016-12-01

    Based on the monthly data of sunspot numbers (SSN), sunspot area of full disc (SSA) and cosmic ray intensity (CRI) observed by neutron monitors (NM) located at Oulu (Cut off Rigidity = 0.8 GV) and Moscow (Cut off Rigidity = 2.3 GV), the trend of solar activity variation and cosmic ray modulation has been studied during the cycles 23 & 24. The SSN have maintained its minimum level exceptionally for a long period (July 2008-Aug. 2009) of time. The intensity of galactic cosmic rays measured by ground based detectors is the highest ever recorded by Oulu NM since April 1964 during the recent solar minimum. Furthermore, the maximum value of SSN is found to be very low in the present cycle in comparison to previous solar cycles (19-23). The correlation coefficient between SSN and CRI without and with time-lag as well as regression analysis during the solar cycle 24 (Jan. 2008-Dec. 2015) has been estimated and compared with previous solar cycle. Based on the maximum value of correlation coefficient, the time-lag during present solar cycle is found to be 4 and 10 months for both the stations, while it is 13-14 months during cycle 23. The behaviour of running cross correlation function has also been examined during present solar cycle and it is found that it attains its maximum value -0.8 to -0.9 for a long duration in comparison to previous cycles. The variation of SSN and SSA has also been compared and found that they are highly correlated to each other (r > .92) for both the cycles. In the light of exceptional behaviour of solar cycle 24, the trend of cosmic ray modulation has been discussed and compared with earlier cycles.

  7. Solar cycle variations of magnetopause locations

    NASA Astrophysics Data System (ADS)

    Němeček, Z.; Šafránková, J.; Lopez, R. E.; Dušík, Š.; Nouzák, L.; Přech, L.; Šimůnek, J.; Shue, J.-H.

    2016-07-01

    The magnetopause location is generally believed to be determined by the solar wind dynamic pressure and by the sign and value of the interplanetary magnetic field vertical (BZ) component. The contribution of other parameters is usually considered to be minor or negligible near the equatorial plane. Recent papers have shown a magnetopause expansion during intervals of a nearly radial IMF but our ability to predict the magnetopause location under steady or slowly changing upstream conditions remains rather weak even if the effect of radial magnetic field is considered. We present a statistical study based on more than 10,000 magnetopause crossings identified in the THEMIS data in the course of the last half of the solar cycle. The observed magnetopause locations are compared with an empirical magnetopause model of Shue et al. (1997) and the sources of differences between observations and model predictions are analyzed. This analysis reveals that the magnetopause location depends on the solar activity being more compressed during the solar maximum. Furthermore, we have found that, beside the solar wind dynamic pressure and vertical magnetic field component, the solar wind speed and ionospheric conductivity (F10.7 used as a proxy) are important physical quantities controlling this compression.

  8. [Suicide and cultural criticism in 19th century Spanish medicine].

    PubMed

    Plumed Domingo, José Javier; Novella, Enric J

    2015-01-01

    This paper explores the major role of suicide in the cultural criticism deployed by 19th century Spanish doctors by analysing the most important theoretical models that inspired their contributions to its aetiology. In the first half of the century, the most commonly debated causal factor was the passions, which were thought to stand in a permanent tension with a free, reflexive and conscious self, in accordance with the spiritualist doctrine that was then dominant. In the context of a growing somatisation of moral and intellectual phenomena, the notion of suicide as an act of free will was later modified, and it became considered the consequence of certain organic disturbances. However, this process did not alter the central role of suicidal behaviour within 19th-century cultural criticism, because the advent of degeneration theory meant that doctors finally had a doctrine that allowed them to combine biological determinism with the extended perception of a moral and social crisis threatening the stability and achievements of bourgeois society.

  9. [The advent of a newborn specialty: 19th century pediatrics].

    PubMed

    Baudon, Jean-Jacques

    2017-04-05

    Pediatrics began under the most unfavorable conditions that are difficult to imagine nowadays. Children at the start of the 19th century were considered as negligible. The death rate was tremendous, increased by the work of children in factories as soon as 6 years of age in textile industries. In upper classes, infants were fed by a wet nurse, far from their parents and death rate was high as well. The emergence of pediatrics was the result of work carried out in adult medicine in the first half of the 19th century: clinical anatomic method, knowledge of contagious diseases even before the discovery of bacteria, birth of bacteriology. During the whole century, infectious diseases contributed in a large part to children mortality, as that of adults, by cholera, typhus, variola, diphtheria, measles and tuberculosis. Progresses noted during the 2nd part of the century resulted from beginning of hygiene, antisepsis, nutrition improvement, taking consideration of children as human being asking for protection. In contrast, therapeutics as serotherapy, vaccinations at the break of the 20th century played a secondary role.

  10. A thermodynamic cycle for the solar cell

    NASA Astrophysics Data System (ADS)

    Alicki, Robert; Gelbwaser-Klimovsky, David; Jenkins, Alejandro

    2017-03-01

    A solar cell is a heat engine, but textbook treatments are not wholly satisfactory from a thermodynamic standpoint, since they present solar cells as directly converting the energy of light into electricity, and the current in the circuit as maintained by an electrostatic potential. We propose a thermodynamic cycle in which the gas of electrons in the p phase serves as the working substance. The interface between the p and n phases acts as a self-oscillating piston that modulates the absorption of heat from the photons so that it may perform a net positive work during a complete cycle of its motion, in accordance with the laws of thermodynamics. We draw a simple hydrodynamical analogy between this model and the ;putt-putt; engine of toy boats, in which the interface between the water's liquid and gas phases serves as the piston. We point out some testable consequences of this model.

  11. Dynamics of solar wind speed: Cycle 23

    NASA Astrophysics Data System (ADS)

    Sarkar, Tushnik; Khondekar, Mofazzal H.; Banerjee, Subrata

    2017-04-01

    A statistical signal processing approach has been made to study the dynamics of the speed of steady flow of hot plasma from the corona of sun known as solar wind generated in Solar Cycle 23. A long time series of solar wind speed of length 2492 days from 1st Jan, 1997 to 28th October, 2003 collected from Coordinated Heliospheric Observations (COHO) data base at NASA's National Space Science Data Center (NSSDC) is investigated for this purpose. Detection of nonlinearity and chaos in dynamics of solar wind speed is the prime objective of this work. In the present analysis delay vector variance (DVV) method is used to detect the existence of nonlinearity within the dynamics of solar wind speed. To explore the signature of the chaos in it multiple statistical methodologies like '0-1' test, the correlation dimension analysis, computation of Information Entropy of the time series and Largest Lyapunov Exponent method have been applied. It has been observed that though the coronal plasma i.e. solar wind flow rate has a nonlinear dynamics but without any chaos. The absence of chaos indicates a probable regular behaviour of the series. The unit magnitude of the Correlation dimension indicates the presence of the deterministic component of the series. Embedding Dimension obtained argues that the deterministic component has dimension of six. The nearly zero value of the Lyapunov exponent claims that the system is conservative and exhibits Lyapunov stability. These revelations establish that not only the solar wind speed alone but the solar wind-magnetosphere coupling is also contributing towards the complexity of the magnetospheric plasma dynamics.

  12. CHARACTERISTICS OF SOLAR MERIDIONAL FLOWS DURING SOLAR CYCLE 23

    SciTech Connect

    Basu, Sarbani; Antia, H. M. E-mail: antia@tifr.res.i

    2010-07-01

    We have analyzed available full-disk data from the Michelson Doppler Imager on board SOHO using the 'ring diagram' technique to determine the behavior of solar meridional flows over solar cycle 23 in the outer 2% of the solar radius. We find that the dominant component of meridional flows during solar maximum was much lower than that during the minima at the beginning of cycles 23 and 24. There were differences in the flow velocities even between the two minima. The meridional flows show a migrating pattern with higher-velocity flows migrating toward the equator as activity increases. Additionally, we find that the migrating pattern of the meridional flow matches those of sunspot butterfly diagram and the zonal flows in the shallow layers. A high-latitude band in meridional flow appears around 2004, well before the current activity minimum. A Legendre polynomial decomposition of the meridional flows shows that the latitudinal pattern of the flow was also different during the maximum as compared to that during the two minima. The different components of the flow have different time dependences, and the dependence is different at different depths.

  13. [The technicalization of medicine in the 19th century].

    PubMed

    Olsén, J E

    2001-01-01

    The paper focuses on the role that instruments played in the medical discourse of the 19th century. Towards the end of the century, instruments had imbued the medical sciences to such an extent that the situation soon was compared to the vernacular confusion of the biblical tower of Babel. Whereas the autonomical recordings of laboratory apparatus, vouched for guarantee against biased test results, clinicians and general practitioners were finding it difficult to incorporate the new techniques into their daily routines. A tension between the instrument as invention, moulded to fit a particular series of experiments, and the instrument as a reproducible item, was inevitable. Hence, the unification of the science and practice of medicine, became an important topic at the international medical meetings of the late 19th century. Seen in the light of the industrialization and urbanization of occidental culture and society, the instrumentation of medicine entailed a number of significant issues which hinged on the relationship between the biological destiny of man and the artificial wonders of technology. Grand metaphors like the organic machine and the human motor, did not only signal a scientific preoccupation with the shortcomings of the living organism as opposed to the perfection of the machine, but also indicated closer ties between the human body and technology at large. In a certain sense, medical instruments, along with apparatuses such as the camera, the steam-engine, the telegraph, the phonograph and the cinematograph, offered a new set-up of codes with which the body and its functions could be reinterpreted. In this respect, the late nineteenth-century strive for the standardisation and unification of medical instruments, was not irreconcilable with the notion of the l'homme moyen, as conceived, for example, in the work of the Belgian mathematician Adolphe Quetelet. The paper outlines the span of medical measuring devices, dating from the sphygmometer of

  14. On the seat of the solar cycle

    NASA Technical Reports Server (NTRS)

    Gough, D.

    1981-01-01

    A discussion of some of the issues raised in connection with the seat of the solar cycle are presented. Is the cycle controlled by a strictly periodic oscillator that operates in the core, or is it a turbulent dynamo confined to the convection zone and possibly a thin boundary layer beneath it? Sunspot statistics are discussed, with a view to ascertaining the length of the memory of the cycle, without drawing a definitive conclusion. Also discussed are some of the processes that might bring about variations delta L and delta R in the luminosity and the radius of the photosphere. It appears that the ratio W = delta lnR/delta lnL increases with the depth of the disturbance that produces the variations, so that imminent observations might determine whether or not the principal dynamical processes are confined to only the outer layers of the Sun.

  15. Solar cycle variations of thermospheric composition at the solstices

    NASA Astrophysics Data System (ADS)

    Qian, Liying; Burns, Alan G.; Solomon, Stanley C.; Wang, Wenbin; Zhang, Yongliang

    2016-04-01

    We examine the solar cycle variability of thermospheric composition (O/N2) at the solstices. Our observational and modeling studies show that the summer-to-winter latitudinal gradient of O/N2 is small at solar minimum but large at solar maximum; O/N2 is larger at solar maximum than at solar minimum on a global-mean basis; there is a seasonal asymmetry in the solar cycle variability of O/N2, with large solar cycle variations in the winter hemisphere and small solar cycle variations in the summer hemisphere. Model analysis reveals that vertical winds decrease the temperature-driven solar cycle variability in the vertical gradient of O/N2 in the summer hemisphere but increase it in the winter hemisphere; consequently, the vertical gradient of O/N2 does not change much in the summer hemisphere over a solar cycle, but it increases greatly from solar minimum to solar maximum in the winter hemisphere; this seasonal asymmetry in the solar cycle variability in the vertical gradient of O/N2 causes a seasonal asymmetry in the vertical advection of O/N2, with small solar cycle variability in the summer hemisphere and large variability in the winter hemisphere, which in turn drives the observed seasonal asymmetry in the solar cycle variability of O/N2. Since the equatorial ionization anomaly suppresses upwelling in the summer hemisphere and strengthens downwelling in the winter hemisphere through plasma-neutral collisional heating and ion drag, locations and relative magnitudes of the equatorial ionization anomaly crests and their solar cycle variabilities can significantly impact the summer-to-winter gradients of O/N2 and their solar cycle variability.

  16. Solar origins of solar wind properties during the cycle 23 solar minimum and rising phase of cycle 24.

    PubMed

    Luhmann, Janet G; Petrie, Gordon; Riley, Pete

    2013-05-01

    The solar wind was originally envisioned using a simple dipolar corona/polar coronal hole sources picture, but modern observations and models, together with the recent unusual solar cycle minimum, have demonstrated the limitations of this picture. The solar surface fields in both polar and low-to-mid-latitude active region zones routinely produce coronal magnetic fields and related solar wind sources much more complex than a dipole. This makes low-to-mid latitude coronal holes and their associated streamer boundaries major contributors to what is observed in the ecliptic and affects the Earth. In this paper we use magnetogram-based coronal field models to describe the conditions that prevailed in the corona from the decline of cycle 23 into the rising phase of cycle 24. The results emphasize the need for adopting new views of what is 'typical' solar wind, even when the Sun is relatively inactive.

  17. Florence Nightingale. A 19th-century mystic.

    PubMed

    Dossey, B M

    1998-06-01

    Florence Nightingale (1820-1910) received a clear and profoundly moving Call to serve God at the age of 16. Through a lifetime of hard work and discipline, she became a practicing mystic in the Western tradition, thereby becoming an instrument of God's love, which was the primary source of her great energy and the fabled "Nightingale power." To understand the life and work of this legendary healer, who forever changed human consciousness, the role of women, and nursing and public health systems in the middle of the 19th century, it is necessary to understand her motivation and inspiration. The purpose of this article is to discuss her life and work in the context of her mystical practice and to show the parallels between her life and the lives of three recognized women mystics.

  18. Cholera in Haiti and Other Caribbean Regions, 19th Century

    PubMed Central

    Szabo, Victoria

    2011-01-01

    Medical journals and other sources do not show evidence that cholera occurred in Haiti before 2010, despite the devastating effect of this disease in the Caribbean region in the 19th century. Cholera occurred in Cuba in 1833–1834; in Jamaica, Cuba, Puerto Rico, St. Thomas, St. Lucia, St. Kitts, Nevis, Trinidad, the Bahamas, St. Vincent, Granada, Anguilla, St. John, Tortola, the Turks and Caicos, the Grenadines (Carriacou and Petite Martinique), and possibly Antigua in 1850–1856; and in Guadeloupe, Cuba, St. Thomas, the Dominican Republic, Dominica, Martinique, and Marie Galante in 1865–1872. Conditions associated with slavery and colonial military control were absent in independent Haiti. Clustered populations, regular influx of new persons, and close quarters of barracks living contributed to spread of cholera in other Caribbean locations. We provide historical accounts of the presence and spread of cholera epidemics in Caribbean islands. PMID:22099117

  19. JANNAF 19th Propulsion Systems Hazards Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Cocchiaro, James E. (Editor); Kuckels, Melanie C. (Editor)

    2000-01-01

    This volume, the first of two volumes is a compilation of 25 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 19th Propulsion Systems Hazards Subcommittee (PSHS) meeting held jointly with the 37th Combustion Subcommittee (CS) and 25th Airbreathing Propulsion Subcommittee (APS), and 1st Modeling and Simulation Subcommittee (MSS) meetings. The meeting was held 13-17 November 2000 at the Naval Postgraduate School and Hyatt Regency Hotel, Monterey, California. Topics covered at the PSHS meeting include: impact and thermal vulnerability of gun propellants; thermal decomposition and cookoff behavior of energetic materials; violent reaction and detonation phenomena of solid energetic materials subjected to shock and impact loading; and hazard classification, and insensitive munitions testing of propellants and propulsion systems.

  20. 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.

  1. Brayton cycle solarized advanced gas turbine

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Described is the development of a Brayton Engine/Generator Set for solar thermal to electrical power conversion, authorized under DOE/NASA Contract DEN3-181. The objective was to design, fabricate, assemble, and test a small, hybrid, 20-kW Brayton-engine-powered generator set. The latter, called a power conversion assembly (PCA), is designed to operate with solar energy obtained from a parobolic dish concentrator, 11 meters in diameter, or with fossil energy supplied by burning fuels in a combustor, or by a combination of both (hybrid model). The CPA consists of the Brayton cycle engine, a solar collector, a belt-driven 20-kW generator, and the necessary control systems for automatic operation in solar-only, fuel-only, and hybrid modes to supply electrical power to a utility grid. The original configuration of the generator set used the GTEC Model GTP36-51 gas turbine engine for the PCA prime mover. However, subsequent development of the GTEC Model AGT101 led to its selection as the powersource for the PCA. Performance characteristics of the latter, thermally coupled to a solar collector for operation in the solar mode, are presented. The PCA was successfully demonstrated in the fuel-only mode at the GTEC Phoenix, Arizona, facilities prior to its shipment to Sandia National Laboratory in Albuquerque, New Mexico, for installation and testing on a test bed concentractor (parabolic dish). Considerations relative to Brayton-engine development using the all-ceramic AGT101 when it becomes available, which would satisfy the DOE heat engine efficiency goal of 35 to 41 percent, are also discussed in the report.

  2. Major Geomagnetic Storms in Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Zheng, Y.

    2013-12-01

    Solar Cycle 24 has produced 11 major geomagnetic storms (where Dstmin < -100 nT) with three in 2011, six in 2012 and two in 2013 (as of 7 August 2013). Detailed analysis of each event will be given in terms of its solar driver(s): CME, coronal hole high speed solar wind stream (HSS), multiple CMEs or interactions between CME and HSS. While some of these storms are associated with a fast and wide CME, the few cases involving slow or common CMEs and interactions with HSS are particularly interesting. These events pose great challenges for accurate space weather forecasting, since operationally the slower or average CMEs tend to receive less attention and are sometimes overlooked altogether. The characteristics of such challenging, not-so-fast yet geoeffective CME events (such as their coronal signatures and interactions with surrounding solar wind structure(s), etc) will be examined in detail, with the goal of extracting common and telltale features, if any, of these CMEs that distinguish them from CMEs in a similar category.

  3. An Improved Solar Cycle Statistical Model for the Projection of Near Future Sunspot Cycles

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Wilson, John W.; Cucinotta, Francis A.

    2004-01-01

    Since the current solar cycle 23 has progressed near the end of the cycle and accurate solar minimum and maximum occurrences have been defined, a statistical model based on the odd-even behavior of historical sunspot cycles was reexamined. Separate calculations of activity levels were made for the rising and declining phases in solar cycle 23, which resulted in improved projection of sunspots in the remainder of cycle 23. Because a fundamental understanding of the transition from cycle to cycle has not been developed, at this time it is assumed for projection purposes that solar cycle 24 will continue at the same activity level in the declining phase of cycle 23. Projection errors in solar cycle 24 can be corrected as the cycle progresses and observations become available because this model is shown to be self-correcting.

  4. Elizabeth Brown and the Classification of Sunspots in the 19th Century

    NASA Astrophysics Data System (ADS)

    Larsen, Kristine

    2014-06-01

    British amateur astronomers collected solar observation data as members of organizations such as the British Astronomical Association (BAA) and Liverpool Astronomical Society (LAS) in the late 1800s. Amateur astronomer Elizabeth Brown (1830-99) served as Solar Section Director of both groups, and not only aggregated solar observations (including hand-drawn illustrations) from observers from around the globe, but worked closely with solar astronomer Edward Maunder and other professionals in an attempt to garner specific types of observations from BAA members in order to answer a number of astronomical questions of the day. For example, she encouraged the monitoring of the growth and decay of sunspot groups and published a number of her own observations of particular groups, urging observers to note whether faculae were seen before the birth of sunspots in a given region, a topic of controversy at that time. She also developed a system for classifying sunspots and sunspot groups based on their appearance, dividing then into 11 types: normal, compound, pairs, clusters, trains, streams, zigzags, elliptical, vertical, nebulous, and dots. This poster will summarize Brown’s important contributions to solar observing in the late 19th century and situate her classification scheme relative to those of A.L. Cortie (1901), M. Waldmeier (1938; 1947) and the modified Zurich system of McIntosh (1966; 1969; 1989).

  5. Solar cycle variation of magnetic flux emergence

    NASA Technical Reports Server (NTRS)

    Davis, J. M.; Golub, L.; Kreiger, A. S.

    1977-01-01

    The number of X-ray bright points (XBP) has been measured from solar X-ray images obtained during two rocket flights in 1976. When compared with the data obtained during the Skylab mission (1973), the number is found to be higher by a factor of 2. As the probability of obtaining the result by chance is less than 1 in 5 million, it is concluded that the number of XBP has increased in the three year interval. As all other indicators of activity have decreased between 1973 and 1976, the cyclical variation of the short-lifetime end of the magnetic-flux-emergence spectrum is out of phase with the solar cycle as defined by active regions or sunspots. Since XBP in 1973 contributed more to the emerging magnetic flux than did active regions, the possibility exists that the total amount of emerging magnetic flux may be maximized at a sunspot minimum.

  6. [Gymnastics and therapeutic gymnastics in 19th century Hungary].

    PubMed

    Kölnei, Lívia

    2009-01-01

    Gymnastics as a way of healing and of preserving health spread in Hungary--almost exclusively among higher classes--only in the first half of the 19th century. The movement was inspired by naturopathic theories of the time, first of all by Christoph Wilhelm Hufeland's macrobiotics, by Vinzenz Priessnitz's hydrotherapy and by his healing gymnastics. Gymnastics has been utilized from the 30ies by a new bough of medicine, orthopaedy. The so called Swedish Gymnastics invented by Per Henrik Ling and by his son Hjalmar Ling or the method of the German gymnast Adolf Spiess were well known in Hungary as well. The pediatrist Agost Schöp-Merei founded the first Institute for Gymnastics in Pest in 1835. As orthopaedy developed, gymnastics was more and more utilized in curing locomotor disorders. Gymnastics however stood in close connection with hydropathy as well. Several institutes for hydropathy and gymnastics were founded in the 50ies and 60ies throughout the country. The most popular of them were those of Károly Siklósy and Sámuel Batizfalvy. Preventive gymnastics gained popularity only in the second half of the 19th century, as 1830 the French gymnast Ignatius Clair moved to Pest and founded the "Pester gymnastische Schule" (Gymnastics School of Pest). This private school flourished till 1863. The Gymnastic Federation of Pest (later National Gymnastics Federation), the first Hungarian sport club was founded in 1866. Tivadar Bakody played an important role in its creation. Gymnastics and sport at the beginning were closely connected with fire-service, so gymnastics clubs often functioned also as fire-guard-bodies. In the 70ies and 80ies the social basis of sport movement was slowly broadened out. The end of the century saw already 44 gymnastics-clubs in Hungary united in a single union, the National Federation of Gymnasts, which organized the education of the profession as well. The trend of development didn't cease up to the Great War. This time the movement was

  7. Deep space telecommunications and the solar cycle: A reappraisal

    NASA Technical Reports Server (NTRS)

    Berman, A. L.

    1978-01-01

    Observations of density enhancement in the near corona at solar cycle (sunspot) maximum have rather uncritically been interpreted to apply equally well to the extended corona, thus generating concern about the quality of outer planet navigational data at solar cycle maximum. Spacecraft have been deployed almost continuously during the recently completed solar cycle 20, providing two powerful new coronal investigatory data sources: (1) in-situ spacecraft plasma measurements at approximately 1 AU, and (2) plasma effects on monochromatic spacecraft signals at all signal closest approach points. A comprehensive review of these (solar cycle 20) data lead to the somewhat surprising conclusions that for the region of interest of navigational data, the highest levels of charged particle corruption of navigational data can be expected to occur at solar cycle minimum, rather than solar cycle maximum, as previously believed.

  8. "Depressive pseudodementia" or "Melancholic dementia": a 19th century view.

    PubMed Central

    Berrios, G E

    1985-01-01

    Nineteenth century views on the interaction between dementia, depressive illness, general paralysis and brain localisation are discussed in the context of a book by A Mairet entitled: Melancholic Dementia. It is shown that by 1883 there was already awareness of the fact that severe affective disorder could lead to cognitive impairment. General paralysis was the commonest diagnosis put forward to account for patients with depression who went on to develop dementia. Patients so diagnosed, however, often recovered and clinical and statistical analysis of Mairet's case histories suggests that some were in fact suffering from depressive pseudodementia. Evidence is marshalled to show that during the 19th century there was wide disagreement concerning the clinical domain, course and even histopathology of general paralysis. This casts doubt on the traditional view that this condition served as "a paradigm" for other psychiatric diseases during this period. It is shown that by the turn of the century these difficulties led to a redefinition of the concept of dementia and to a marked narrowing of the clinical bounds of general paralysis. PMID:3889224

  9. [Cholera in Europe and Denmark in the 19th century].

    PubMed

    Bonderup, G

    1996-01-01

    There are several reasons for dealing with cholera in the 19th century: it acted as a spotlight throwing into sharp relief the darkest corners of society that are seldom mentioned in the sources. We learn about everyday life in large parts of the population, especially the poor. The fight against the disease also reveals how a society worked socially and politically. When cholera arrived in Europe -- the first time was in the 1830's and several times after that--the population reacted very violently, often by lynching doctors, while the authorities more or less let matters take their course. That is why international researchers have come to see cholera as a catalyst for the constantly latent social unrest following in the train of wars and revolutions. During my research on cholera in Denmark it became clear to me that matters were different here. There were no riots, nor any signs of social unrest--neither before nor after the outbreak of cholera. On the contrary, the authorities and the population joined forces against the epidemic. There was an atmosphere of mutual trust, and almost everybody turned out to be worthy of such trust. That points to a balanced society based on consensus, so cholera also functions as a detector of the fundamental structure of a society.

  10. Austrian pharmacy in the 18 and 19th century.

    PubMed

    Kletter, Christa

    2010-01-01

    This overview reflects the extensive changes in the health care system which had significant effects on the apothecaryâs profession and education. In the 18(th) century Maria Theresia assigned Gerard van Swieten to modernize the medical curriculum and to work out reforms for health care. The resulting sanitary bill released in 1770 and amended in 1773 became effective for the whole empire and influenced greatly the apothecaryâs profession. The Viennese Medical Faculty continued to be the supervisory body for the apothecaries, a situation which prolonged the conflicts between the faculty and the apothecaries. The financial and social distress prevalent in the 19(th) century also affected the apothecary business and led to a crisis of the profession. Furthermore, the apothecariesâ missing influence over the sanitary authorities delayed the release of a badly needed new apothecary bill until 1906. The introduction of a specific pharmaceutical curriculum at the university in 1853 was a great step forward to improve the pharmaceutical education. Nevertheless, the secondary school exam was not compulsory for the studies until 1920 and, therefore, the graduates were not on a par with other university graduates before that date. Women, except nuns, were not allowed to work as pharmacists until 1900.

  11. [Origin of animal experimentation legislation in the 19th century].

    PubMed

    Pocard, M

    1999-01-01

    The first legislation in the world, designed to protect animals used in research, was passed in England in 1876, and is still in force today. It is one of the strictest in Europe. At the same period, France had no such law, and was the country conducting the greatest amount of animal experimentation. Comparing, these two countries, in the middle of the 19th century, can account for this difference. The most important difference seems to be related to the theological question: are animals endowed with a soul? Saint Augustine, claimed, in the 4th century, perhaps because of an experiment with the centipede, that animals do not have a soul. In the 17th century, René Descartes, using a different philosophical system, reached a similar conclusion, in France. On the other hand, under the influence of Charles Darwin, England rejected the Roman Catholic conclusion, about the soul of animals. The industrial revolution, occurring earlier in England than in France, also changed the society, developing urban areas, where people were cut off from rural life and changing human relationships with animals. The industrial revolution enabled the development of the press, giving impetus to public opinion. These facts, combined with a caution of science, which was more developed in England than in France, brought about the first important "anti-doctor" campaign.

  12. Faces and Photography in 19th-Century Visual Science.

    PubMed

    Wade, Nicholas J

    2016-09-01

    Reading faces for identity, character, and expression is as old as humanity but representing these states is relatively recent. From the 16th century, physiognomists classified character in terms of both facial form and represented the types graphically. Darwin distinguished between physiognomy (which concerned static features reflecting character) and expression (which was dynamic and reflected emotions). Artists represented personality, pleasure, and pain in their paintings and drawings, but the scientific study of faces was revolutionized by photography in the 19th century. Rather than relying on artistic abstractions of fleeting facial expressions, scientists photographed what the eye could not discriminate. Photography was applied first to stereoscopic portraiture (by Wheatstone) then to the study of facial expressions (by Duchenne) and to identity (by Galton and Bertillon). Photography opened new methods for investigating face perception, most markedly with Galton's composites derived from combining aligned photographs of many sitters. In the same decade (1870s), Kühne took the process of photography as a model for the chemical action of light in the retina. These developments and their developers are described and fixed in time, but the ideas they initiated have proved impossible to stop.

  13. Laser cleaning of 19th century Congo rattan mats

    NASA Astrophysics Data System (ADS)

    Carmona, N.; Oujja, M.; Roemich, H.; Castillejo, M.

    2011-09-01

    There is a growing interest by art conservators for laser cleaning of organic materials, such as wooden artworks, paper and textiles, since traditional cleaning with solvents can be a source of further decay and mechanical cleaning may be too abrasive for sensitive fibers. In this work we present a successful laser cleaning approach for 19th century rattan mats from the Brooklyn Museum collection of African Art, now part of the study collection at the Conservation Center in New York. Tests were carried out using the fundamental (1064 nm) and second harmonic (532 nm) wavelength of a Q-switched Nd:YAG laser to measure threshold values both for surface damage and color changes for different types of rattan samples. The irradiated substrates were investigated by optical microscopy, scanning electron microscopy and by UV-vis spectroscopy in order to determine the efficiency of laser cleaning and to assess possible deterioration effects that may have occurred as a result of laser irradiation. The study showed that by using the laser emission at 532 nm, a wavelength for which photon energy is below the bond dissociation level of the main cellulosic compounds and the water absorption is negligible, it is possible to select a range of laser fluences to remove the black dust layer without damaging the rattan material.

  14. Florence Nightingale: a 19th-century mystic.

    PubMed

    Dossey, Barbara M

    2010-03-01

    Florence Nightingale (1820-1910) received a clear and profoundly moving Call to serve God at the age of 16. Through a lifetime of hard work and discipline, she became a practicing mystic in the Western tradition, thereby becoming an instrument of God's love, which was the primarily source of her great energy and the fabled "Nightingale power." To understand the life and work of this legendary healer, who forever changed human consciousness, the role of women, and nursing and public health systems in the middle of the 19th century, it is necessary to understand her motivation and inspiration. This article will discuss her life and work in the context of her mystical practice and to show the parallels between her life and the lives of three recognized women mystics. In her epic Crimean war mission (1854-1856) of leading and directing women nurses in the army hospital at Scutari, Turkey, Florence Nightingale burst into world consciousness as a spiritual beacon of hope and compassion for all who suffered. Her historic breakthrough achievement--pioneering the modern administrative role of nurse superintendent with measurable outcomes supported by irrefutable data--in the face of incredible adversity was merely the cornerstone of her life work.

  15. William Prout: early 19th century physician-chemist.

    PubMed

    Rosenfeld, Louis

    2003-04-01

    In the early 19th century, the discoveries of new substances in the healthy and diseased body spawned a search for chemical explanations for physiologic phenomena to guide medical diagnosis and control therapy. William Prout's work on the nature and treatment of diseases of the urinary organs established his reputation as one of Britain's most distinguished physiological chemists. Prout was very skeptical of chemical remedies because of possible side effects, but he suggested iodine treatment for goiter. He emphasized that a satisfactory diet should include carbohydrates, fats, protein, and water. In 1824, he showed that the acid of the gastric juice was hydrochloric acid. Prout applied chemical methods and reasoning to physiology and was criticized for his view that the body's vital functions could be explained by chemistry. His remedy for lack of progress in animal chemistry was for physiologists to become chemists. Prout stimulated much discussion on atomic theory by his hypothesis that the atomic weights of all chemical elements are whole-number multiples of the atomic weight of hydrogen and that the chemical elements were condensed from hydrogen atoms.

  16. Asymmetric behavior of different solar activity features over solar cycles 20-23

    NASA Astrophysics Data System (ADS)

    Bankoti, Neeraj Singh; Joshi, Navin Chandra; Pande, Bimal; Pande, Seema; Uddin, Wahab; Pandey, Kavita

    2011-07-01

    This paper presents the study of normalized north-south asymmetry, cumulative normalized north-south asymmetry and cumulative difference indices of sunspot areas, solar active prominences (at total, low (⩽40°) and high (⩾50°) latitudes) and H α solar flares from 1964 to 2008 spanning the solar cycles 20-23. Three different statistical methods are used to obtain the asymmetric behavior of different solar activity features. Hemispherical distribution of activity features shows the dominance of activities in northern hemisphere for solar cycle 20 and in southern hemisphere for solar cycles 21-23 excluding solar active prominences at high latitudes. Cumulative difference index of solar activity features in each solar cycle is observed at the maximum of the respective solar cycle suggesting a cyclic behavior of approximately one solar cycle length. Asymmetric behavior of all activity features except solar active prominences at high latitudes hints at the long term periodic trend of eight solar cycles. North-south asymmetries of SAP (H) express the specific behavior of solar activity at high solar latitudes and its behavior in long-time scale is distinctly opposite to those of other activity features. Our results show that in most cases the asymmetry is statistically highly significant meaning thereby that the asymmetries are real features in the N-S distribution of solar activity features.

  17. Variations of the solar wind and solar cycle in the last 300 years

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Silverman, S.

    1980-01-01

    The past history of the solar wind and solar cycle, inferred from records of geomagnetics and aurora, is examined. Records show that the solar wind apparently varied in a systematic manner throughout the period from 1770 to 1857 and that the period around 1810 resembled the 1901 minimum geomagnetic disturbance. Results show that the solar wind and hence the Sun changes on a time scale long compared to a solar cycle and short compared to the Maunder minimum. The inclusion of a study on the solar wind and solar cycle variations for the SCADM mission is discussed.

  18. [Developments in neurophysiology in the 19th century].

    PubMed

    Hess, C W

    1994-04-19

    The rise of neurophysiology in the 19th century was kindled by Luigi Aloysius Galvani's revolutionary claim for animal electricity at the end of the preceding century. He was first challenged by Allessandro Giuseppe Antonio Anastasio Volta who showed that the muscle twitch in Galvani's experiment was the result of electric stimulation rather than of an enabled biological current. The controversy between Galvani and Volta became a predominant and stimulating issue among the scientists of the early century and found its ultimate elucidation only 40 years later by the pioneering work of Carlo Matteucci of Pisa and Emil Heinrich Du Bois-Reymond of Berlin, who both deserve the reknown as founders of modern neurophysiology. As the first influential promoter and mastermind of the experimental physiology, François Magendie of Paris primarily investigated the nervous system and inaugurated the lesion experiments to clarify specific functions of neural structures. Johannes Müller founded the German school of physiology with its eminent neurophysiological offspring: Du Bois-Reymond, Hermann Ludwig Ferdinand von Helmholtz, and Eduard Friedrich Wilhelm Pflüger. It was Helmholtz's merit to have for the first time precisely assessed the motor conduction velocity by measuring the time interval between two different stimulation sites of the sciatic nerve of the frog. In their brilliant work published in 1870 Gustav Theodor Fritsch and Eduard Hitzig demonstrated that appropriately located focal electrical stimulation of the exposed cortex of dogs induces movement of the contralateral limbs and unequivocally disproved the then prevailing dogma of holistic capacity of the hemispheres, which denied localised functions within the cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Absinthism: a fictitious 19th century syndrome with present impact

    PubMed Central

    Padosch, Stephan A; Lachenmeier, Dirk W; Kröner, Lars U

    2006-01-01

    Absinthe, a bitter spirit containing wormwood (Artemisia absinthium L.), was banned at the beginning of the 20th century as consequence of its supposed unique adverse effects. After nearly century-long prohibition, absinthe has seen a resurgence after recent de-restriction in many European countries. This review provides information on the history of absinthe and one of its constituent, thujone. Medical and toxicological aspects experienced and discovered before the prohibition of absinthe are discussed in detail, along with their impact on the current situation. The only consistent conclusion that can be drawn from those 19th century studies about absinthism is that wormwood oil but not absinthe is a potent agent to cause seizures. Neither can it be concluded that the beverage itself was epileptogenic nor that the so-called absinthism can exactly be distinguished as a distinct syndrome from chronic alcoholism. The theory of a previous gross overestimation of the thujone content of absinthe may have been verified by a number of independent studies. Based on the current available evidence, thujone concentrations of both pre-ban and modern absinthes may not have been able to cause detrimental health effects other than those encountered in common alcoholism. Today, a questionable tendency of absinthe manufacturers can be ascertained that use the ancient theories of absinthism as a targeted marketing strategy to bring absinthe into the spheres of a legal drug-of-abuse. Misleading advertisements of aphrodisiac or psychotropic effects of absinthe try to re-establish absinthe's former reputation. In distinction from commercially manufactured absinthes with limited thujone content, a health risk to consumers is the uncontrolled trade of potentially unsafe herbal products such as absinthe essences that are readily available over the internet. PMID:16722551

  20. Variability of Clouds Over a Solar Cycle

    NASA Technical Reports Server (NTRS)

    Yung, Yuk L.

    2002-01-01

    One of the most controversial aspects of climate studies is the debate over the natural and anthropogenic causes of climate change. Historical data strongly suggest that the Little Ice Age (from 1550 to 1850 AD when the mean temperature was colder by about 1 C) was most likely caused by variability of the sun and not greenhouse molecules (e.g., CO2). However, the known variability in solar irradiance and modulation of cosmic rays provides too little energy, by many orders of magnitude, to lead to climate changes in the troposphere. The conjecture is that there is a 'trigger mechanism'. This idea may now be subjected to a quantitative test using recent global datasets. Using the best available modern cloud data from International Satellite Cloud Climatology Project (ISCCP), Svensmark and Friis-Christensen found a correlation of a large variation (3-4%) in global cloud cover with the solar cycle. The work has been extended by Svensmark and Marsh and Svensmark. The implied forcing on climate is an order of magnitude greater than any previous claims. Are clouds the long sought trigger mechanism? This discovery is potentially so important that it should be corroborated by an independent database, and, furthermore, it must be shown that alternative explanations (i.e., El Nino) can be ruled out. We used the ISCCP data in conjunction with the Total Ozone Mapping Spectrometer (TOMS) data to carry out in in depth study of the cloud trigger mechanism.

  1. Solar UV Variations During the Decline of Cycle 23

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew, T.; Cebula, Richard P.

    2011-01-01

    Characterization of temporal and spectral variations in solar ultraviolet irradiance over a solar cycle is essential for understanding the forcing of Earth's atmosphere and climate. Satellite measurements of solar UV variability for solar cycles 21, 22, and 23 show consistent solar cycle irradiance changes at key wavelengths (e.g. 205 nm, 250 nm) within instrumental uncertainties. All historical data sets also show the same relative spectral dependence for both short-term (rotational) and long-term (solar cycle) variations. Empirical solar irradiance models also produce long-term solar UV variations that agree well with observational data. Recent UV irradiance data from the Solar Radiation and Climate Experiment (SORCE) Spectral Irradiance Monitor (SIM) and Solar Stellar Irradiance Comparison Experiment (SOLSTICE) instruments covering the declining phase of Cycle 23 present a different picture oflong-term solar variations from previous results. Time series of SIM and SOLSTICE spectral irradiance data between 2003 and 2007 show solar variations that greatly exceed both previous measurements and predicted irradiance changes over this period, and the spectral dependence of the SIM and SOLSTICE variations during these years do not show features expected from solar physics theory. The use of SORCE irradiance variations in atmospheric models yields substantially different middle atmosphere ozone responses in both magnitude and vertical structure. However, short-term solar variability derived from SIM and SOLSTICE UV irradiance data is consistent with concurrent solar UV measurements from other instruments, as well as previous results, suggesting no change in solar physics. Our analysis of short-term solar variability is much less sensitive to residual instrument response changes than the observations of long-term variations. The SORCE long-term UV results can be explained by under-correction of instrument response changes during the first few years of measurements

  2. Contributions to the 19th International Cosmic Ray Conference

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Various aspects of cosmic radiation, its measurements and their patterns are presented. Measurement techniques and variations in solar cosmic ray patterns and calculations of elemental abundances are reviewed.

  3. INTERNAL-CYCLE VARIATION OF SOLAR DIFFERENTIAL ROTATION

    SciTech Connect

    Li, K. J.; Xie, J. L.; Shi, X. J.

    2013-06-01

    The latitudinal distributions of the yearly mean rotation rates measured by Suzuki in 1998 and 2012 and Pulkkinen and Tuominen in 1998 are utilized to investigate internal-cycle variation of solar differential rotation. The rotation rate at the solar equator seems to have decreased since cycle 10 onward. The coefficient B of solar differential rotation, which represents the latitudinal gradient of rotation, is found to be smaller in the several years after the minimum of a solar cycle than in the several years after the maximum time of the cycle, and it peaks several years after the maximum time of the solar cycle. The internal-cycle variation of the solar rotation rates looks similar in profile to that of the coefficient B. A new explanation is proposed to address such a solar-cycle-related variation of the solar rotation rates. Weak magnetic fields may more effectively reflect differentiation at low latitudes with high rotation rates than at high latitudes with low rotation rates, and strong magnetic fields may more effectively repress differentiation at relatively low latitudes than at high latitudes. The internal-cycle variation is inferred as the result of both the latitudinal migration of the surface torsional pattern and the repression of strong magnetic activity in differentiation.

  4. Solar spectral irradiance variability in cycle 24: observations and models

    NASA Astrophysics Data System (ADS)

    Marchenko, Sergey V.; DeLand, Matthew T.; Lean, Judith L.

    2016-12-01

    Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265 and 500 nm during the ongoing cycle 24. We supplement the OMI data with concurrent observations from the Global Ozone Monitoring Experiment-2 (GOME-2) and Solar Radiation and Climate Experiment (SORCE) instruments and find fair-to-excellent, depending on wavelength, agreement among the observations, and predictions of the Naval Research Laboratory Solar Spectral Irradiance (NRLSSI2) and Spectral And Total Irradiance REconstruction for the Satellite era (SATIRE-S) models.

  5. Ottoman Greek Education System and Greek Girls' Schools in Istanbul (19th and 20th Centuries)

    ERIC Educational Resources Information Center

    Daglar Macar, Oya

    2010-01-01

    Modernization efforts in education, which were initiated in the 19th century, can be seen as forerunners of the modernization attempts in the Republic period. In this article, Greek education system in the Ottoman Empire will be discussed and the effects and importance of the changes observed in Greek girls' education in 19th and 20th centuries on…

  6. Reading for Moral Progress: 19th Century Institutions Promoting Social Change. Occasional Papers No. 207.

    ERIC Educational Resources Information Center

    Davis, Donald G., Jr.; And Others

    The three papers in this document examine the motives behind the collecting and loaning of publications in the 19th century. They describe the effects of three discrete movements designed to assist religious, military, and academic endeavors. The first paper, "Bread Upon the Waters: The Printed Word in Sunday Schools in 19th Century England…

  7. Predicting Solar Cycle 24 Using a Geomagnetic Precursor Pair

    NASA Technical Reports Server (NTRS)

    Pesnell, W. Dean

    2014-01-01

    We describe using Ap and F(10.7) as a geomagnetic-precursor pair to predict the amplitude of Solar Cycle 24. The precursor is created by using F(10.7) to remove the direct solar-activity component of Ap. Four peaks are seen in the precursor function during the decline of Solar Cycle 23. A recurrence index that is generated by a local correlation of Ap is then used to determine which peak is the correct precursor. The earliest peak is the most prominent but coincides with high levels of non-recurrent solar activity associated with the intense solar activity of October and November 2003. The second and third peaks coincide with some recurrent activity on the Sun and show that a weak cycle precursor closely following a period of strong solar activity may be difficult to resolve. A fourth peak, which appears in early 2008 and has recurrent activity similar to precursors of earlier solar cycles, appears to be the "true" precursor peak for Solar Cycle 24 and predicts the smallest amplitude for Solar Cycle 24. To determine the timing of peak activity it is noted that the average time between the precursor peak and the following maximum is approximately equal to 6.4 years. Hence, Solar Cycle 24 would peak during 2014. Several effects contribute to the smaller prediction when compared with other geomagnetic-precursor predictions. During Solar Cycle 23 the correlation between sunspot number and F(10.7) shows that F(10.7) is higher than the equivalent sunspot number over most of the cycle, implying that the sunspot number underestimates the solar-activity component described by F(10.7). During 2003 the correlation between aa and Ap shows that aa is 10 % higher than the value predicted from Ap, leading to an overestimate of the aa precursor for that year. However, the most important difference is the lack of recurrent activity in the first three peaks and the presence of significant recurrent activity in the fourth. While the prediction is for an amplitude of Solar Cycle 24 of

  8. The mid 19th and early 20th Century Pull of a Nearby Eclipse Shadow Path

    NASA Astrophysics Data System (ADS)

    Bonifácio, Vitor

    2012-09-01

    The unique observing conditions allowed by total solar eclipses made them a highly desirable target of 19th and early 20th century astronomical expeditions, particularly after 1842. Due to the narrowness of the lunar shadow at the Earth's surface this usually implied traveling to faraway locations with all the subsequent inconveniences, in particular, high costs and complex logistics. A situation that improved as travel became faster, cheaper and more reliable. The possibility to observe an eclipse in one's own country implied no customs, no language barriers, usually shorter travelling distances and the likely support of local and central authorities. The eclipse proximity also provided a strong argument to pressure the government to support the eclipse observation. Sometimes the scientific elite would use such high profile events to rhetorically promote broader goals. In this paper we will analyse the motivation, goals, negotiating strategies and outcomes of the Portuguese eclipse expeditions made between 1860 and 1914. We will focus, in particular, on the observation of the solar eclipses of 22 December 1870 and 17 April 1912. The former allowed the start-up of astrophysical studies in the country while the movie obtained at the latter led Francisco da Costa Lobo to unexpectedly propose a polar flattening of the Moon.

  9. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  10. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, D.; Bohn, M.S.; Williams, T.A.

    1995-05-23

    A hybrid combined cycle power plant is described including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production. 1 figure.

  11. Major Space Weather Events during the Weak Solar Cycle 24

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk

    2012-01-01

    We report on the level of solar activity during cycles 23 and 24 as the cycles build toward the corresponding solar maxima. The prolonged minimum period that followed solar cycle 23 and the weaker magnetic field at the poles seem to have resulted in a weaker level of activity during cycle 24. The double speak structure often observed in the maximum phases seems to be present during cycle 24, with the first peak having a sunspot number of only N90. large solar energetic particle (SEP) events, major geomagnetic storms, and radio-emitting interplanetary shocks have been observed in relatively sma:ier numbers. While the number of large SEP events during the rise phase of cycles 24 is not too different from that of cycle 23, they are generally less intense. Five ground level enhancement (GlE) events occurred up to the first activity peak in cycle 23, while a lone GlE event has been observed during the corresponding phase in cycle 24. There were 35 large (Dst S -100 nT) geomagnetic storms during the first 4.5 years of cycle 23, while only 5 occurred during cycle 24. The subdued activity during cycle 23 is consistent with the low numbers of type II radio bursts, full halo CMEs, and interplanetary shocks.

  12. DMSP Auroral Charging at Solar Cycle 24 Maximum

    NASA Technical Reports Server (NTRS)

    Chandler, M.; Parker, L. Neergaard; Minow, J. I.

    2013-01-01

    It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions. These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka. These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.

  13. Search for relationship between duration of the extended solar cycles and amplitude of sunspot cycle

    NASA Astrophysics Data System (ADS)

    Tlatov, A. G.

    2007-12-01

    Duration of the extended solar cycles is taken into the consideration. The beginning of cycles is counted from the moment of polarity reversal of large-scale magnetic field in high latitudes, occurring in the sunspot cycle n till the minimum of the cycle n+2. The connection between cycle duration and its amplitude is established. Duration of the ``latent" period of evolution of extended cycle between reversals and a minimum of the current sunspot cycle is entered. It is shown, that the latent period of cycles evolution is connected with the next sunspot cycle amplitude and can be used for the prognosis of a level and time of a sunspot maximum. The 24th activity cycle prognosis is made. The found dependences correspond to transport dynamo model of generation of solar cyclicity, it is possible with various speed of meridional circulation. Long-term behavior of extended cycle's lengths and connection with change of a climate of the Earth is considered.%

  14. Development of Solar Activity Cycle 24: Some Comments

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    Our forecast for the development phase of the solar cycle 23 turned out to be right on the mark; one of the very few to have acquired this status out of nearly 40 forecasts made for cycle 23. This is the first time in the 400 year history of the sunspot observations that a forecast was made for a solar cycle, it was defended against a severe peer criticism and came out true. We review the details of our actual forcast and how they fared as the events unfolded during cycle 23. We then consider the present status of the solar wind, the geomagnetic planetary indices, and the recovery of the galactic cosmic rays from cycle 23 modulation. Next, we draw inferences as to what to expect for the development phase of solar cycle 24. We are aware that several forecasts have already been made for the development of solar cycle 24 activity. They cover all possible scenarios, ranging from the most active to the quietest ever cycle. Clearly, some of these forecasts are unlikely to materialize. We discuss emerging details of the physical link between the observations and the workings of the solar dynamo.

  15. Forecasting the Peak of the Present Solar Activity Cycle

    NASA Astrophysics Data System (ADS)

    Hamid, Rabab; Marzouk, Beshir

    2016-07-01

    Solar forecasting of the level of sun Activity is very important subject for all space programs. Most predictions are based on the physical conditions prevailing at or before the solar 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 solar 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 solar 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.

  16. 25 MeV Solar Proton Events in Cycle 24 and Previous Cycles

    NASA Astrophysics Data System (ADS)

    Richardson, I. G.; Cane, H. V.; von Rosenvinge, T. T.

    2014-12-01

    We summarize observations of nearly 1000 solar energetic particle events that include 25 MeV protons made by Goddard instruments on various spacecraft (IMPs IV, V, 7, 8, ISEE-3) and by other instruments on SOHO, since 1967, encompassing solar cycles 20 to 24. We also include recent observations of such events from the STEREO spacecraft. These extended observations place studies focusing on Cycles 23 and 24 in a broader context. For example, the time distribution of 25 MeV proton events varies from cycle to cycle such that each cycle is unique. In the current cycle, ~25 MeV proton events were absent during the preceding solar minimum, whereas earlier minima showed occasional, often reasonably intense events, and there have been, so far, fewer exceptionally intense events compared to Cycles 22 and 23, though Cycle 21 also apparently lacked such events.

  17. Sunspot areas and tilt angles for solar cycles 7-10

    NASA Astrophysics Data System (ADS)

    Senthamizh Pavai, V.; Arlt, R.; Dasi-Espuig, M.; Krivova, N. A.; Solanki, S. K.

    2015-12-01

    Aims: Extending the knowledge about the properties of solar cycles into the past is essential for understanding the solar dynamo. This paper aims to estimate areas of sunspots observed by Schwabe in 1825-1867 and to calculate the tilt angles of sunspot groups. Methods: The sunspot sizes in Schwabe's drawings are not to scale and need to be converted into physical sunspot areas. We employed a statistical approach assuming that the area distribution of sunspots was the same in the 19th century as it was in the 20th century. Results: Umbral areas for about 130 000 sunspots observed by Schwabe were obtained, as well as the tilt angles of sunspot groups assuming them to be bipolar. There is, of course, no polarity information in the observations. The annually averaged sunspot areas correlate reasonably with sunspot number. We derived an average tilt angle by attempting to exclude unipolar groups with a minimum separation of the two alleged polarities and an outlier rejection method which follows the evolution of each group and detects the moment it turns unipolar at its decay. As a result, the tilt angles, although displaying considerable scatter, average to 5̊.85 ± 0, with the leading polarity located closer to the equator, in good agreement with tilt angles obtained from 20th century data sets. Sources of uncertainties in the tilt angle determination are discussed and need to be addressed whenever different data sets are combined. The sunspot area and tilt angle data are provided at the CDS. The sunspot area and tilt angle data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A73

  18. White-light corona and solar polar magnetic field strength over solar cycles

    NASA Astrophysics Data System (ADS)

    Rušin, V.; Saniga, M.; Komžík, R.

    2014-10-01

    We discuss the large-scale structure of the solar corona, in particular its helmet streamers, as observed during total solar eclipses around maxima of solar cycles and make its comparison with solar polar magnetic field strength as observed by the Wilcox Solar Observatory (WSO) since 1976. Even though the magnetic field strength at the solar poles around cycle minima decreased minimally twice in the last forty years, distributions of helmet streamers around the Sun in different cycles around cycle maxima remain nearly the same. This indicates that large-scale magnetic structures governing the shape and evolution of helmet streamers must be of a different nature than those related with solar polar fields.

  19. Solar thermal organic rankine cycle for micro-generation

    NASA Astrophysics Data System (ADS)

    Alkahli, N. A.; Abdullah, H.; Darus, A. N.; Jalaludin, A. F.

    2012-06-01

    The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.

  20. ANALYSIS OF SUNSPOT AREA OVER TWO SOLAR CYCLES

    SciTech Connect

    De Toma, G.; Chapman, G. A.; Preminger, D. G.; Cookson, A. M.

    2013-06-20

    We examine changes in sunspots and faculae and their effect on total solar irradiance during solar cycles 22 and 23 using photometric images from the San Fernando Observatory. We find important differences in the very large spots between the two cycles, both in their number and time of appearance. In particular, there is a noticeable lack of very large spots in cycle 23 with areas larger than 700 millionths of a solar hemisphere which corresponds to a decrease of about 40% relative to cycle 22. We do not find large differences in the frequencies of small to medium spots between the two cycles. There is a decrease in the number of pores and very small spots during the maximum phase of cycle 23 which is largely compensated by an increase during other phases of the solar cycle. The decrease of the very large spots, in spite of the fact that they represent only a few percent of all spots in a cycle, is primarily responsible for the observed changes in total sunspot area and total sunspot deficit during cycle 23 maximum. The cumulative effect of the decrease in the very small spots is an order of magnitude smaller than the decrease caused by the lack of large spots. These data demonstrate that the main difference between cycles 22 and 23 was in the frequency of very large spots and not in the very small spots, as previously concluded. Analysis of the USAF/NOAA and Debrecen sunspot areas confirms these findings.

  1. Analysis of Sunspot Area over Two Solar Cycles

    NASA Astrophysics Data System (ADS)

    de Toma, G.; Chapman, G. A.; Preminger, D. G.; Cookson, A. M.

    2013-06-01

    We examine changes in sunspots and faculae and their effect on total solar irradiance during solar cycles 22 and 23 using photometric images from the San Fernando Observatory. We find important differences in the very large spots between the two cycles, both in their number and time of appearance. In particular, there is a noticeable lack of very large spots in cycle 23 with areas larger than 700 millionths of a solar hemisphere which corresponds to a decrease of about 40% relative to cycle 22. We do not find large differences in the frequencies of small to medium spots between the two cycles. There is a decrease in the number of pores and very small spots during the maximum phase of cycle 23 which is largely compensated by an increase during other phases of the solar cycle. The decrease of the very large spots, in spite of the fact that they represent only a few percent of all spots in a cycle, is primarily responsible for the observed changes in total sunspot area and total sunspot deficit during cycle 23 maximum. The cumulative effect of the decrease in the very small spots is an order of magnitude smaller than the decrease caused by the lack of large spots. These data demonstrate that the main difference between cycles 22 and 23 was in the frequency of very large spots and not in the very small spots, as previously concluded. Analysis of the USAF/NOAA and Debrecen sunspot areas confirms these findings.

  2. Solar Cycle Characteristics and Their Relationship with Dynamo Theory

    NASA Astrophysics Data System (ADS)

    Otkidychev, P. A.; Popova, H.; Popov, V.

    2015-12-01

    We try to establish the correlation between different parameters of “butterfly-diagrams” derived from the analysis of solar observational data for the 12-23 solar activity cycles and the values in the models of α-Ω­dynamo using RGO - NASA/Marshall data set. We have ascertained that there is a linear relationship between S and BT/L for all the investigated cycles, where S is the mean area of the sunspots (umbrae), B is the mean magnetic field strength, T is duration of a cycle and L is the mean latitude of the sunspots in a cycle.

  3. Solar Cycle in the Heliosphere and Cosmic Rays

    DTIC Science & Technology

    2014-10-23

    information if it does not display a currently valid OMB control number. 1. REPORT DATE 23 OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED 4...cycle, varying from nearly no spots at solar minimum to high values of about 200 at solar maximum. To date , current cycle No. 24 which started in December...cycle 19–24 (see Table 1 for dates ). These are shown in 12-month increments starting with the year after the sunspot minimum for each cycle. Only the

  4. Data Assimilation Approach for Forecast of Solar Activity Cycles

    NASA Astrophysics Data System (ADS)

    Kitiashvili, Irina N.

    2016-11-01

    Numerous attempts to predict future solar cycles are mostly based on empirical relations derived from observations of previous cycles, and they yield a wide range of predicted strengths and durations of the cycles. Results obtained with current dynamo models also deviate strongly from each other, thus raising questions about criteria to quantify the reliability of such predictions. The primary difficulties in modeling future solar activity are shortcomings of both the dynamo models and observations that do not allow us to determine the current and past states of the global solar magnetic structure and its dynamics. Data assimilation is a relatively new approach to develop physics-based predictions and estimate their uncertainties in situations where the physical properties of a system are not well-known. This paper presents an application of the ensemble Kalman filter method for modeling and prediction of solar cycles through use of a low-order nonlinear dynamo model that includes the essential physics and can describe general properties of the sunspot cycles. Despite the simplicity of this model, the data assimilation approach provides reasonable estimates for the strengths of future solar cycles. In particular, the prediction of Cycle 24 calculated and published in 2008 is so far holding up quite well. In this paper, I will present my first attempt to predict Cycle 25 using the data assimilation approach, and discuss the uncertainties of that prediction.

  5. Solar Cycle Spectral Irradiance Variation and Stratospheric Ozone

    NASA Astrophysics Data System (ADS)

    Stolarski, R. S.; Swartz, W. H.; Jackman, C. H.; Fleming, E. L.

    2011-12-01

    Recent measurements from the SIM instrument on the SORCE satellite have been interpreted by Harder et al (Geophys. Res. Lett., 36, L07801, doi:10.1029/2008GL036797, 2009) as implying a different spectral irradiance variation over the solar cycle than that put forward by Lean (Geophys. Res. Lett., 27, 2425-2428, 2000). When we inserted this new wavelength dependent solar cycle variation into our 3D CCM we found a different solar cycle dependence of the ozone concentration as a function of altitude from that we derived using the traditional Lean wavelength dependence. Examination of these results led us to realize that the main issue is the solar cycle variation of radiation at wavelengths less than 240 nm versus the solar cycle variation of radiation at wavelengths between 240 nm and 300 nm. The impact of wavelengths less than 240 nm occurs through photodissociation of O2 leading to the production of ozone. The impact of wavelengths between 240 nm and 300 nm occurs through photodissociation of O3 leading to an increase in O atoms and enhanced ozone destruction. Thus one wavelength region gives an in-phase relationship of ozone with the solar cycle while the other wavelength region gives an out-of-phase relationship of ozone with the solar cycle. We have used the Goddard two-dimensional (2D) photochemistry transport model to examine this relationship in more detail. We calculate the altitude and latitude sensitivity of ozone to changes in the solar UV irradiance as a function of wavelength. These results can be used to construct the ozone response to arbitrary wavelength dependencies of solar UV variation.

  6. Characteristics of solar wind density depletions during solar cycles 23 and 24

    NASA Astrophysics Data System (ADS)

    Park, K.; Lee, J.; Oh, S.; Yi, Y.

    2014-12-01

    Solar wind density depletions are generally believed to be caused by the interplanetary (IP) shocks. However, there are other cases that are hardly associated with IP shocks. To better understand the cause of the density depletions, we investigate the solar wind parameters and interplanetary magnetic field (IMF) data related to the solar wind density depletion events during the period from 1996 to 2013 that are obtained with the Advanced Composition Explorer (ACE) and the WIND satellite. As a result, we found that the solar wind density has an anti-correlation with IMF strength during all events of solar wind density depletion, regardless of the presence of IP shocks. We thus argue that IMF strength is an important factor in understanding the nature of solar wind density depletion. Since IMF strength varies with solar cycle, we also investigate the characteristics of solar wind density depletion events in different phases of solar cycle as an attempt to find its connection to the sun.

  7. Cosmic Ray Helium Intensities over the Solar Cycle from ACE

    NASA Technical Reports Server (NTRS)

    DeNolfo, G. A.; Yanasak, N. E.; Binns, W. R.; Cohen, C. M. S.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink. P. L.; Israel, M. H.; Lave, K.; Leske, R. A.; Mewaldt, R. A.; Moskalenko, I. V.; Ogliore, R.; Stone, E. C.; Von Rosenvinge, T. T.; Wiedenback, M. E.

    2007-01-01

    Observations of cosmic-ray helium energy spectra provide important constraints on cosmic ray origin and propagation. However, helium intensities measured at Earth are affected by solar modulation, especially below several GeV/nucleon. Observations of helium intensities over a solar cycle are important for understanding how solar modulation affects galactic cosmic ray intensities and for separating the contributions of anomalous and galactic cosmic rays. The Cosmic Ray Isotope Spectrometer (CRIS) on ACE has been measuring cosmic ray isotopes, including helium, since 1997 with high statistical precision. We present helium elemental intensities between approx. 10 to approx. 100 MeV/nucleon from the Solar Isotope Spectrometer (SIS) and CRIS observations over a solar cycle and compare these results with the observations from other satellite and balloon-borne instruments, and with GCR transport and solar modulation models.

  8. Forecast for solar cycle 23 activity: a progress report

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2001-08-01

    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 solar cycle 23 activity (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 solar 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 solar, 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 activity (Sunspot Numbers, SSN) in the next cycle. He posited that the message was embedded in the geomagnetic activity (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 solar poloidal fields, near a minimum, emerge as the toroidal fields on opposite sides of the solar equator. This is known as the Solar Dynamo Model. One can speculate that the precursor poloidal solar field is entrained in the high speed solar wind streams (HSSWS) from the coronal holes which are observed at Earth's orbit during the descending phase of the previous cycle. The interaction

  9. Encore of the Bashful ballerina in solar cycle 23

    NASA Astrophysics Data System (ADS)

    Mursula, K.; Virtanen, I. I.

    2009-04-01

    The rotation averaged location of the heliospheric current sheet has been found to be shifted systematically southward for about three years in the late declining to minimum phase of the solar cycle. This behaviour, called by the concept of the Bashful ballerina, has earlier been shown to be valid at least during the active solar cycle of the last century since the late 1920s. Recently, Zhao et al have analysed the WSO observations and conclude that there is no southward coning in HCS or north-south difference in the heliospheric magnetic field during the late declining phase of solar cycle 23. In disagreement with these results, we find that there is a similar but smaller southward shift of the HCS and dominance of the northern field area as in all previous solar cycles. The present smaller asymmetry is in agreement with an earlier observation based on long-term geomagnetic activity that solar hemispheric asymmetry is larger during highly active solar cycles. Moreover, we connect the smallness of shift to the structure of the solar magnetic field with an exceptionally large tilt. We also discuss the cause of the differences between the two approaches reaching different conclusions.

  10. 4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON RIGHT. 20TH CENTURY ELECTRIC LIFT LOCKS ON LEFT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  11. The Electric Whirl in the 19th and 21st Centuries

    NASA Astrophysics Data System (ADS)

    Daffron, John A.; Greenslade, Thomas B.

    2012-12-01

    The electric whirl or electric fly in Fig. 1 is one of the many electrostatic demonstrations from the 19th century that continue to amuse and delight students today. It also introduces them to some good physics.

  12. PHOTOCOPY OF 19th CENTURY PHOTO OF THE ORIGINAL BRIDGE, courtesy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOCOPY OF 19th CENTURY PHOTO OF THE ORIGINAL BRIDGE, courtesy of Erie Railway Company - Erie Railway, Buffalo Division, Bridge 361.66, Genesee River, State Route 436, Portageville, Wyoming County, NY

  13. Heat and Kinetic Theory in 19th-Century Physics Textbooks: The Case of Spain.

    ERIC Educational Resources Information Center

    Vaquero, Jose M.; Santos, Andres

    2001-01-01

    Presents an analysis of the contents of 19th century Spanish textbooks. These textbooks are centered on imponderable fluids, the concept of energy, the mechanical theory of heat, and the kinetic theory of gases. (SAH)

  14. Forecasting decadal and shorter time-scale solar cycle features

    NASA Astrophysics Data System (ADS)

    Dikpati, Mausumi

    2016-07-01

    Solar energetic particles and magnetic fields reach the Earth through the interplanetary medium and affect it in various ways, producing beautiful aurorae, but also electrical blackouts and damage to our technology-dependent economy. The root of energetic solar outputs is the solar activity cycle, which is most likely caused by dynamo processes inside the Sun. It is a formidable task to accurately predict the amplitude, onset and peak timings of a solar cycle. After reviewing all solar cycle prediction methods, including empirical as well as physical model-based schemes, I will describe what we have learned from both validation and nonvalidation of cycle 24 forecasts, and how to refine the model-based schemes for upcoming cycle 25 forecasts. Recent observations indicate that within a solar cycle there are shorter time-scale 'space weather' features, such as bursts of various forms of activity with approximately one year periodicity. I will demonstrate how global tachocline dynamics could play a crucial role in producing such space weather. The National Center for Atmospheric Research is sponsored by the National Science Foundation.

  15. Heat and Kinetic Theory in 19th-Century Physics Textbooks: The Case of Spain

    NASA Astrophysics Data System (ADS)

    Vaquero, Joseb M.; Santos, Andrebs

    Spain was a scientifically backward country in the early 19th century. The causes were various political events, the War of Independence, and the reign of Fernando VII. The introduction of contemporary physics into textbooks was therefore a slow process. An analysis of the contents of 19th-century Spanish textbooks is presented here, centred on imponderable fluids, the concept of energy, the mechanical theory of heat, and the kinetic theory of gases.

  16. Solar cycle effect in SBUV/SBUV 2 ozone data

    NASA Astrophysics Data System (ADS)

    Gruzdev, Aleksandr

    Effect of the 11-year solar cycle on stratospheric ozone is analyzed using the data of ozone measurements with SBUV/SBUV 2 instruments aboard Nimbus 7, NOAA 9, NOAA 11, NOAA 14, NOAA 16, and NOAA 17-NOAA 19 satellites for 1978-2012 (ftp://toms.gsfc.nasa.gov/pub/sbuv/). High-resolution spectral and cross-spectral methods as well as the method of multiple linear regression were used for the analysis. The regression model takes into account the annual variation, the linear trend, the solar cycle effect and the effects on ozone of the products of the Pinatubo volcano eruption and the quasi-biennial oscillations in the equatorial stratospheric wind. The cross-spectral analysis of ozone concentration and 10.7 cm solar radio flux shows that, generally, 11-year ozone variations in the upper stratosphere and lower mesosphere lag behind while ozone variations in the low-latitude lower stratosphere lead the solar cycle. The phase shift between the ozone variations and the solar cycle reaches pi/2 in 35-40 km layer over the tropics and in the southern hemisphere lower stratosphere. Calculations show that taking into account the phase shift is especially important for correct estimation of the ozone response to the solar cycle in the tropical middle stratosphere. Local maxima of ozone sensitivity to the 11-year solar cycle are noted around a year below the stratopause (45-50 km), in 30-35 km layer in the middle stratosphere, and in the polar lower stratosphere. The sensitivity of the ozone response to the solar cycle for the whole period of 1978-2012 is less than that for the period of 1978-2003 which does not include the 24th solar cycle with anomalously small amplitude. The ozone response is seasonally dependent. Maximal amplitudes of the ozone response are characteristic for polar latitudes during winter-spring periods. For example ozone changes related to the solar cycle can reach 5% in the low and middle latitudes during the 1978-2012 period, while winter-spring ozone

  17. Development of solar activity in 24th cycle: scenario of 15th cycle?

    NASA Astrophysics Data System (ADS)

    Lozytsky, V.; Efimenko, V.

    2012-12-01

    For more precise definition of prognosis of 24th cycle, the peculiarities of growth of solar activity was studied in previous 23 cycles. The interest was focused on a phase of sharp increasing of activity, beginning from 20th month of cycles. The sufficiently close correlation was found between smoothed Wolf's number in the cycle maximum Wmax and increment of sunspot's number on phase of activity increasing. From this analysis follows that for 24th cycle the following parameters are expected: Wmax = 105±11, аnd time of maximum - middle 2013. If this prognosis will be come true, the 24th cycle will be similar to cycle No. 15.

  18. Trends and solar cycle effects in mesospheric ice clouds

    NASA Astrophysics Data System (ADS)

    Lübken, Franz-Josef; Berger, Uwe; Fiedler, Jens; Baumgarten, Gerd; Gerding, Michael

    Lidar observations of mesospheric ice layers (noctilucent clouds, NLC) are now available since 12 years which allows to study solar cycle effects on NLC parameters such as altitudes, bright-ness, and occurrence rates. We present observations from our lidar stations in Kuehlungsborn (54N) and ALOMAR (69N). Different from general expectations the mean layer characteris-tics at ALOMAR do not show a persistent anti-correlation with solar cycle. Although a nice anti-correlation of Ly-alpha and occurrence rates is detected in the first half of the solar cycle, occurrence rates decreased with decreasing solar activity thereafter. Interestingly, in summer 2009 record high NLC parameters were detected as expected in solar minimum conditions. The morphology of NLC suggests that other processes except solar radiation may affect NLC. We have recently applied our LIMA model to study in detail the solar cycle effects on tempera-tures and water vapor concentration the middle atmosphere and its subsequent influence on mesospheric ice clouds. Furthermore, lower atmosphere effects are implicitly included because LIMA nudges to the conditions in the troposphere and lower stratosphere. We compare LIMA results regarding solar cycle effects on temperatures and ice layers with observations at ALO-MAR as well as satellite borne measurements. We will also present LIMA results regarding the latitude variation of solar cycle and trends, including a comparison of northern and southern hemisphere. We have adapted the observation conditions from SBUV (wavelength and scatter-ing angle) in LIMA for a detailed comparison with long term observations of ice clouds from satellites.

  19. An early solar dynamo prediction: Cycle 23 is approximately cycle 22

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth H.; Pesnell, W. Dean

    1993-01-01

    In this paper, we briefly review the 'dynamo' and 'geomagnetic precursor' methods of long-term solar activity forecasting. These methods depend upon the most basic aspect of dynamo theory to predict future activity, future magnetic field arises directly from the magnification of pre-existing magnetic field. We then generalize the dynamo technique, allowing the method to be used at any phase of the solar cycle, through the development of the 'Solar Dynamo Amplitude' (SODA) index. This index is sensitive to the magnetic flux trapped within the Sun's convection zone but insensitive to the phase of the solar cycle. Since magnetic fields inside the Sun can become buoyant, one may think of the acronym SODA as describing the amount of buoyant flux. Using the present value of the SODA index, we estimate that the next cycle's smoothed peak activity will be about 210 +/- 30 solar flux units for the 10.7 cm radio flux and a sunspot number of 170 +/- 25. This suggests that solar cycle #23 will be large, comparable to cycle #22. The estimated peak is expected to occur near 1999.7 +/- 1 year. Since the current approach is novel (using data prior to solar minimum), these estimates may improve when the upcoming solar minimum is reached.

  20. A solar cycle timing predictor - The latitude of active regions

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth H.

    1990-01-01

    A 'Spoerer butterfly' method is used to examine solar cycle 22. It is shown from the latitude of active regions that the cycle can now be expected to peak near November 1989 + or - 8 months, basically near the latter half of 1989.

  1. SOLAR CYCLE VARIATION OF THE INTER-NETWORK MAGNETIC FIELD

    SciTech Connect

    Jin, Chunlan; Wang, Jingxiu

    2015-06-20

    The solar inter-network magnetic field is the weakest component of solar magnetism, but it contributes most of the solar surface magnetic flux. The study of its origin has been constrained by the inadequate tempospatial resolution and sensitivity of polarization observations. With dramatic advances in spatial resolution and detecting sensitivity, the solar spectropolarimetry provided by the Solar Optical Telescope on board Hinode in an interval from the solar minimum to maximum of cycle 24 opens an unprecedented opportunity to study the cyclic behavior of the solar inter-network magnetic field. More than 1000 Hinode magnetograms observed from 2007 January to 2014 August are selected in the study. It has been found that there is a very slight correlation between sunspot number and magnetic field at the inter-network flux spectrum. From solar minimum to maximum of cycle 24, the flux density of the solar inter-network field is invariant, at 10 ± 1 G. The observations suggest that the inter-network magnetic field does not arise from flux diffusion or flux recycling of solar active regions, thereby indicating the existence of a local small-scale dynamo. Combining the full-disk magnetograms observed by the Solar and Heliospheric Observatory/Michelson Doppler Imager and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager in the same period, we find that the area ratio of the inter-network region to the full disk of the Sun apparently decreases from solar minimum to maximum but always exceeds 60%, even in the phase of solar maximum.

  2. Solar Cycle: Magnetized March to Equator

    NASA Video Gallery

    Bands of magnetized solar material – with alternating south and north polarity – march toward the sun's equator. Comparing the evolution of the bands with the sunspot number in each hemisphere over...

  3. Variation of solar acoustic emission and its relation to phase of the solar cycle

    NASA Astrophysics Data System (ADS)

    Chen, Ruizhu; Zhao, Junwei

    2016-05-01

    Solar acoustic emission is closely related to solar convection and photospheric magnetic field. Variation of acoustic emission and its relation to the phase of solar cycles are important to understand dynamics of solar cycles and excitation of acoustic waves. In this work we use 6 years of SDO/HMI Dopplergram data to study acoustic emissions of the whole sun and of the quiet-sun regions, respectively, in multiple acoustic frequency bands. We show the variation of acoustic emission from May 2010 to April 2016, covering half of the solar cycle 24, and analyze its correlation with the solar activity level indexed by daily sunspot number and total magnetic flux. Results show that the correlation between the whole-Sun acoustic emission and the solar activity level is strongly negative for low frequencies between 2.5 and 4.5 mHz, but strongly positive for high frequencies between 4.5 and 6.0 mHz. For high frequencies, the acoustic emission excess in sunspot halos overwhelms the emission deficiency in sunspot umbrae and penumbrae. The correlation between the acoustic emission in quiet regions and the solar activity level is negative for 2.5-4.0 mHz and positive for 4.0-5.5 mHz. This shows that the solar background acoustic power, with active regions excluded, also varies during a solar cycle, implying the excitation frequencies or depths are highly related to the solar magnetic field.

  4. Modeling and optimization of a hybrid solar combined cycle (HYCS)

    NASA Astrophysics Data System (ADS)

    Eter, Ahmad Adel

    2011-12-01

    The main objective of this thesis is to investigate the feasibility of integrating concentrated solar power (CSP) technology with the conventional combined cycle technology for electric generation in Saudi Arabia. The generated electricity can be used locally to meet the annual increasing demand. Specifically, it can be utilized to meet the demand during the hours 10 am-3 pm and prevent blackout hours, of some industrial sectors. The proposed CSP design gives flexibility in the operation system. Since, it works as a conventional combined cycle during night time and it switches to work as a hybrid solar combined cycle during day time. The first objective of the thesis is to develop a thermo-economical mathematical model that can simulate the performance of a hybrid solar-fossil fuel combined cycle. The second objective is to develop a computer simulation code that can solve the thermo-economical mathematical model using available software such as E.E.S. The developed simulation code is used to analyze the thermo-economic performance of different configurations of integrating the CSP with the conventional fossil fuel combined cycle to achieve the optimal integration configuration. This optimal integration configuration has been investigated further to achieve the optimal design of the solar field that gives the optimal solar share. Thermo-economical performance metrics which are available in the literature have been used in the present work to assess the thermo-economic performance of the investigated configurations. The economical and environmental impact of integration CSP with the conventional fossil fuel combined cycle are estimated and discussed. Finally, the optimal integration configuration is found to be solarization steam side in conventional combined cycle with solar multiple 0.38 which needs 29 hectare and LEC of HYCS is 63.17 $/MWh under Dhahran weather conditions.

  5. [JAN JĘDRZEJEWICZ AND EUROPEAN ASTRONOMY OF THE 2ND HALF OF THE 19TH CENTURY].

    PubMed

    Siuda-Bochenek, Magda

    2015-01-01

    Jan Jędrzejewicz was an amateur astronomer who in the 2nd half of the 19th century created an observation centre, which considering the level of research was comparable to the European ones. Jędrzejewicz settled down in Plonsk in 1862 and worked as a doctor ever since but his greatest passion was astronomy, to which he dedicated all his free time. In 1875 Jędrzejewicz finished the construction of his observatory. He equipped it with basic astronomical and meteorological instruments, then began his observations and with time he became quite skilled in it. Jędrzejewicz focused mainly on binary stars but he also pointed his telescopes at the planets of the solar system, the comets, the Sun, as well as all the phenomena appearing in the sky at that time. Thanks to the variety of the objects observed and the number of observations he stood out from other observers in Poland and took a very good position in the mainstream of the 19th-century astronomy in Europe. Micrometer observations of binary stars made in Płońsk gained recognition in the West and were included in the catalogues of binary stars. Interest in Jędrzejewicz and his observatory was confirmed by numerous references in the English "Nature" magazine.

  6. Discrepancy in behavior of different solar proxies in cycle 23

    NASA Astrophysics Data System (ADS)

    Lukianova, R.

    2009-04-01

    The Sun can influence the Earth climate through mechanisms that are not fully understood but which can be linked to solar variations of luminosity, magnetic field, UV radiation, solar flares and modulation of the cosmic ray intensity. Several proxies are used to characterize the Sun behavior and its influence on the geospheres. Solar activity over long time scales has usually been studied with the use of sunspot numbers (SN). The integrated radio flux from the solar disc (F10.7 index) follows the SN. Regular direct monitoring of solar irradiance has been made by satellites since 1978, resulting in time series of total solar irradiance (TSI) and variations of solar EUV irradiance (MgII index). The long-term components of all four solar proxies are expected to correlate linearly with each other. The situation was stable until the last solar maximum. Actually, cycle 23 had two maxima: one near middle of 2000 and another near end of 2001. According to SN, the magnitude of the first maximum was larger, whereas according to irradiance proxies, TSI and MgII, the second maximum was significantly higher. After this episode of enhanced irradiance (and until now) the mutual correspondence between published solar indices has been changed resulting in significant divergence. The present paper is aimed to the evaluation of discrepancy observed in different solar proxies. We examine the solar activity, namely the SN, F10.7, TSIs and MgII time series, in order to emphasis its unusual mutual behavior during the declining phase of cycle 23. Behavior of the solar indices is compared with the global ionospheric response using the F2 layer critical frequency from many observatories spread over the globe.

  7. Solar cycle variations in the interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Slavin, J. A.; Smith, E. J.

    1983-01-01

    ISEE 3 interplanetary magnetic field measurements have been used to extend the NSSDC hourly averaged IMF composite data set through mid-1982. Most of sunspot cycle 20 (start:1964) and the first half of cycle 21 (start:1976) are now covered. The average magnitude of the field was relatively constant over cycle 20 with approx. 5-10% decreases in 1969 and 1971, when the Sun's polar regions changed polarity, and a 20% decrease in 1975-6 around solar minimum. Since the start of the new cycle, the total field strength has risen with the mean for the first third of 1982 being about 40% greater than the cycle 20 average. As during the previous cycle, an approx. 10% drop in IMF magnitude accompanied the 1980 reversal of the solar magnetic field. While the interplanetary magnetic field is clearly stronger during the present solar cycle, another 5-7 years of observations will be needed to determine if cycle 21 exhibits the same modest variations as the last cycle. Accordingly, it appears at this time that intercycle changes in IMF magnitude may be much larger than the intracycle variations.

  8. The solar cycle variation of coronal mass ejections and the solar wind mass flux

    NASA Technical Reports Server (NTRS)

    Webb, David F.; Howard, Russell A.

    1994-01-01

    Coronal mass ejections (CMEs) are an important aspect of coronal physics and a potentially significant contributor to perturbations of the solar wind, such as its mass flux. Sufficient data on CMEs are now available to permit study of their longer-term occurrency patterns. Here we present the results of a study of CME occurrence rates over more than a complete 11-year solar sunspot cycle and a comparison of these rates with those of other activity related to CMEs and with the solar wind particle flux at 1 AU. The study includes an evaluation of correlations to the CME rates, which include instrument duty cycles, visibility functions, mass detection thresholds, and geometrical considerations. The main results are as follows: (1) The frequency of occurrence of CMEs tends to track the solar activity cycle in both amplitude and phase; (2) the CME rates from different instruments, when corrected for both duty cycles and visibility functions, are reasonably consistent; (3) considering only longer-term averages, no one class of solar activity is better correlated with CME rate than any other; (4) the ratio of the annualized CME to solar wind mass flux tends to track the solar cycle; and (5) near solar maximum, CMEs can provide a significant fraction (i.e., approximately equals 15%) of the average mass flux to the near-ecliptic solar wind.

  9. WHAT CAUSES THE INTER-SOLAR-CYCLE VARIATION OF TOTAL SOLAR IRRADIANCE?

    SciTech Connect

    Xiang, N. B.; Kong, D. F.

    2015-12-15

    The Physikalisch Meteorologisches Observatorium Davos total solar irradiance (TSI), Active Cavity Radiometer Irradiance Monitoring TSI, and Royal Meteorological Institute of Belgium TSI are three typical TSI composites. Magnetic Plage Strength Index (MPSI) and Mount Wilson Sunspot Index (MWSI) should indicate the weak and strong magnetic field activity on the solar full disk, respectively. Cross-correlation (CC) analysis of MWSI with three TSI composites shows that TSI should be weakly correlated with MWSI, and not be in phase with MWSI at timescales of solar cycles. The wavelet coherence (WTC) and partial wavelet coherence (PWC) of TSI with MWSI indicate that the inter-solar-cycle variation of TSI is also not related to solar strong magnetic field activity, which is represented by MWSI. However, CC analysis of MPSI with three TSI composites indicates that TSI should be moderately correlated and accurately in phase with MPSI at timescales of solar cycles, and that the statistical significance test indicates that the correlation coefficient of three TSI composites with MPSI is statistically significantly higher than that of three TSI composites with MWSI. Furthermore, the cross wavelet transform (XWT) and WTC of TSI with MPSI show that the TSI is highly related and actually in phase with MPSI at a timescale of a solar cycle as well. Consequently, the CC analysis, XWT, and WTC indicate that the solar weak magnetic activity on the full disk, which is represented by MPSI, dominates the inter-solar-cycle variation of TSI.

  10. What Causes the Inter-solar-cycle Variation of Total Solar Irradiance?

    NASA Astrophysics Data System (ADS)

    Xiang, N. B.; Kong, D. F.

    2015-12-01

    The Physikalisch Meteorologisches Observatorium Davos total solar irradiance (TSI), Active Cavity Radiometer Irradiance Monitoring TSI, and Royal Meteorological Institute of Belgium TSI are three typical TSI composites. Magnetic Plage Strength Index (MPSI) and Mount Wilson Sunspot Index (MWSI) should indicate the weak and strong magnetic field activity on the solar full disk, respectively. Cross-correlation (CC) analysis of MWSI with three TSI composites shows that TSI should be weakly correlated with MWSI, and not be in phase with MWSI at timescales of solar cycles. The wavelet coherence (WTC) and partial wavelet coherence (PWC) of TSI with MWSI indicate that the inter-solar-cycle variation of TSI is also not related to solar strong magnetic field activity, which is represented by MWSI. However, CC analysis of MPSI with three TSI composites indicates that TSI should be moderately correlated and accurately in phase with MPSI at timescales of solar cycles, and that the statistical significance test indicates that the correlation coefficient of three TSI composites with MPSI is statistically significantly higher than that of three TSI composites with MWSI. Furthermore, the cross wavelet transform (XWT) and WTC of TSI with MPSI show that the TSI is highly related and actually in phase with MPSI at a timescale of a solar cycle as well. Consequently, the CC analysis, XWT, and WTC indicate that the solar weak magnetic activity on the full disk, which is represented by MPSI, dominates the inter-solar-cycle variation of TSI.

  11. ENIGMA OF THE SOLAR CYCLE 4 STILL NOT RESOLVED

    SciTech Connect

    Zolotova, N. V.; Ponyavin, D. I.

    2011-08-01

    In this paper, the problem of the unusually long 4th sunspot cycle is discussed: was the length of this cycle exceptionally large or really composed of two short cycles? Analyzing the latitude-time diagram in 1784-1798, reconstructed from the drawings by Staudacher, Hamilton, and Gimingham, we suggest that the 4th cycle length can be a result of an impulse of activity in the northern hemisphere during the descending phase. The local minimum in 1793 can be just a gap between impulses of the solar activity, similar to the declining phase in the southern hemisphere of the long cycle 20. The long declining phase of cycle 4 is that the minimum in 1793 may also be due to lack of data. We have shown that sparse observations of the sunspots, in the second half of cycle 4, do not prove the existence of the 'lost' tiny cycle from 1793 to 1800.

  12. Prediction of solar activity from solar background magnetic field variations in cycles 21-23

    SciTech Connect

    Shepherd, Simon J.; Zharkov, Sergei I.; Zharkova, Valentina V. E-mail: s.zharkov@hull.ac.uk

    2014-11-01

    A comprehensive spectral analysis of both the solar 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 solar 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 solar dynamo waves assumed to form in different layers of the solar 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 solar activity. 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.

  13. Solar cycle variation of thermospheric nitric oxide at solstice

    NASA Technical Reports Server (NTRS)

    Gerard, J.-C.; Fesen, C. G.; Rusch, D. W.

    1990-01-01

    A coupled, two-dimensional, chemical-diffusive model of the thermosphere is used to study the role of solar activity in the global distribution of nitric oxide. The model calculates self-consistently the zonally averaged temperature, circulation, and composition for solstice under solar maximum and solar minimum conditions. A decrease of the NO density by a factor of three to four in the E region is predicted from solar maximum to solar minimum. It is found that the main features of the overall morphology and the changes induced by the solar cycle are well reproduced in the model, although some details are not satisfactorily predicted. The sensitivity of the NO distribution to eddy transport and to the quenching of metastable N(2D) atoms by atomic oxygen is also described.

  14. Hubble Space Telescope solar cell module thermal cycle test

    NASA Technical Reports Server (NTRS)

    Douglas, Alexander; Edge, Ted; Willowby, Douglas; Gerlach, Lothar

    1992-01-01

    The Hubble Space Telescope (HST) solar array consists of two identical double roll-out wings designed after the Hughes flexible roll-up solar array (FRUSA) and was developed by the European Space Agency (ESA) to meet specified HST power output requirements at the end of 2 years, with a functional lifetime of 5 years. The requirement that the HST solar array remain functional both mechanically and electrically during its 5-year lifetime meant that the array must withstand 30,000 low Earth orbit (LEO) thermal cycles between approximately +100 and -100 C. In order to evaluate the ability of the array to meet this requirement, an accelerated thermal cycle test in vacuum was conducted at NASA's Marshall Space Flight Center (MSFC), using two 128-cell solar array modules which duplicated the flight HST solar array. Several other tests were performed on the modules. The thermal cycle test was interrupted after 2,577 cycles, and a 'cold-roll' test was performed on one of the modules in order to evaluate the ability of the flight array to survive an emergency deployment during the dark (cold) portion of an orbit. A posttest static shadow test was performed on one of the modules in order to analyze temperature gradients across the module. Finally, current in-flight electrical performance data from the actual HST flight solar array will be tested.

  15. Beginning of the new solar cycle (cycle 24) in the large-scale open solar magnetic field

    NASA Astrophysics Data System (ADS)

    Ivanov, K. G.; Kharshiladze, A. F.

    2008-06-01

    It is proposed to determined minimums of the 11-year solar cycles based on a minimal flux of the large-scale open solar magnetic field. The minimal fluxes before the finished cycle 23 (Carrington rotation CR 1904) and the started cycle 24 (CR 2054, April 2007) were equal to 1.8 × 1022 and 1.2 × 1022 μs, respectively. The long-term tendency toward an approach to a deep minimum of solar activity is confirmed. On the assumption that magnetic flux variations from minimums to maximums are proportional to each other, the anticipated value of the maximal Wolf number during cycle 24 is estimated as W max = 80.

  16. Evolution of solar wind turbulence and intermittency over the solar cycle

    NASA Astrophysics Data System (ADS)

    Väisänen, Pauli; Virtanen, Ilpo; Echim, Marius; Munteanu, Costel; Mursula, Kalevi

    2016-04-01

    Solar wind is a natural, near-by plasma physics laboratory, which offers possibilities to study plasma physical phenomena over a wide range of parameter values that are difficult to reach in ground-based laboratories. Accordingly, the solar wind is subject of many studies of, e.g., intermittency, turbulence and other nonlinear space plasma phenomena. Turbulence is an important feature of the solar wind dynamics, e.g., for the energy transfer mechanisms and their scale invariance, the solar wind evolution, the structure of the heliospheric magnetic field (HMF), the particle energization and heating, and for phenomena related to solar wind interaction with the planetary plasma systems. Here we analyse high resolution measurements of the solar wind and the heliospheric magnetic field provided by several ESA and NASA satellites, including ACE, STEREO, Ulysses and Cluster. This collection of satellites allows us to compile and study nearly 20 years of high-resolution solar wind and HMF measurements from the start of solar cycle 23 to the current declining phase of solar cycle 24. Long-term studies require homogeneity and, therefore, we pay great attention to the reliability and consistency of the data, in particular to instrumental defects like spin harmonics, the purity of the solar wind and its possible contamination in the foreshock by magnetospheric ions. We study how the different key-descriptors of turbulence like the slope of the power law of power spectral density and the kurtosis of the fluctuations of the heliospheric magnetic field vary over the solar cycle.

  17. Connection between solar activity cycles and grand minima generation

    NASA Astrophysics Data System (ADS)

    Vecchio, A.; Lepreti, F.; Laurenza, M.; Alberti, T.; Carbone, V.

    2017-03-01

    Aims: The revised dataset of sunspot and group numbers (released by WDC-SILSO) and the sunspot number reconstruction based on dendrochronologically dated radiocarbon concentrations have been analyzed to provide a deeper characterization of the solar activity main periodicities and to investigate the role of the Gleissberg and Suess cycles in the grand minima occurrence. Methods: Empirical mode decomposition (EMD) has been used to isolate the time behavior of the different solar activity periodicities. A general consistency among the results from all the analyzed datasets verifies the reliability of the EMD approach. Results: The analysis on the revised sunspot data indicates that the highest energy content is associated with the Schwabe cycle. In correspondence with the grand minima (Maunder and Dalton), the frequency of this cycle changes to longer timescales of 14 yr. The Gleissberg and Suess cycles, with timescales of 60-120 yr and 200-300 yr, respectively, represent the most energetic contribution to sunspot number reconstruction records and are both found to be characterized by multiple scales of oscillation. The grand minima generation and the origin of the two expected distinct types of grand minima, Maunder and longer Spörer-like, are naturally explained through the EMD approach. We found that the grand minima sequence is produced by the coupling between Gleissberg and Suess cycles, the latter being responsible for the most intense and longest Spörer-like minima (with typical duration longer than 80 yr). Finally, we identified a non-solar component, characterized by a very long scale oscillation of 7000 yr, and the Hallstatt cycle ( 2000 yr), likely due to the solar activity. Conclusions: These results provide new observational constraints on the properties of the solar cycle periodicities, the grand minima generation, and thus the long-term behavior of the solar dynamo.

  18. Geomagnetic research in the 19th century: a case study of the German contribution

    NASA Astrophysics Data System (ADS)

    Schröder, W.; Wiederkehr, K.-H.

    2001-10-01

    Even before the discovery of electromagnetism by Oersted, and before the work of Ampère, who attributed all magnetism to the flux of electrical currents, A.v. Humboldt and Hansteen had turned to geomagnetism. Through the ``Göttinger Magnetischer Verein'', a worldwide cooperation under the leadership of Gauss came into existence. Even today, Gauss's theory of geomagnetism is one of the pillars of geomagnetic research. Thereafter, J.v. Lamont, in Munich, took over the leadership in Germany. In England, the Magnetic Crusade was started by the initiative of John Herschel and E. Sabine. At the beginning of the 1840s, James Clarke Ross advanced to the vicinity of the southern magnetic pole on the Antarctic Continent, which was then quite unknown. Ten years later, Sabine was able to demonstrate solar-terrestrial relations from the data of the colonial observatories. In the 1980s, Arthur Schuster, following Balfour Stewart's ideas, succeeded in interpreting the daily variations of the electrical process in the high atmosphere. Geomagnetic research work in Germany was given a fresh impetus by the programme of the First Polar Year 1882-1883. Georg Neumayer, director of the ``Deutsche Seewarte'' in Hamburg, was one of the initiators of the Polar Year. He forged a close cooperation with the newly founded ``Kaiserliches Marineobservatorium'' in Wilhelmshaven, and also managed to gain the collaboration of the ``Gauss-Observatorium für Erdmagnetismus'' in Göttingen under E. Schering. In the Polar Year, the first automatic recording magnetometers (Kew-Model) were used in the German observatory at Wilhelmshaven. Here, M. Eschenhagen, who later became director of the geomagnetic section in the new Meteorological Magnetic Observatory in Potsdam, deserves special credit. Early hypotheses of geomagnetism and pioneering palaeomagnetic experiments are briefly reviewed. The essential seismological investigations at the turn of the 19th to the 20th century are also briefly described as

  19. Interannual Variations of MLS Carbon Monoxide Induced by Solar Cycle

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Wu, Dong L.; Ruzmaikin, Alexander

    2013-01-01

    More than eight years (2004-2012) of carbon monoxide (CO) measurements from the Aura Microwave Limb Sounder (MLS) are analyzed. The mesospheric CO, largely produced by the carbon dioxide (CO2) photolysis in the lower thermosphere, is sensitive to the solar irradiance variability. The long-term variation of observed mesospheric MLS CO concentrations at high latitudes is likely driven by the solar-cycle modulated UV forcing. Despite of different CO abundances in the southern and northern hemispheric winter, the solar-cycle dependence appears to be similar. This solar signal is further carried down to the lower altitudes by the dynamical descent in the winter polar vortex. Aura MLS CO is compared with the Solar Radiation and Climate Experiment (SORCE) total solar irradiance (TSI) and also with the spectral irradiance in the far ultraviolet (FUV) region from the SORCE Solar-Stellar Irradiance Comparison Experiment (SOLSTICE). Significant positive correlation (up to 0.6) is found between CO and FUVTSI in a large part of the upper atmosphere. The distribution of this positive correlation in the mesosphere is consistent with the expectation of CO changes induced by the solar irradiance variations.

  20. Statistical pecularities of 24th cycle of solar activity

    NASA Astrophysics Data System (ADS)

    Efimenko, V.; Lozitsky, V.

    2016-06-01

    Current 24th cycle of solar activity is anomalous if following aspects: 1) it had non-monotonous phase of grown, and on different times of this phase it demonstrated peculiarities of both middle and weak cycle, 2) peak of cycle was two-top, and second top was higher than first on about 15 units of averages Wolf's number (in old classification) that is maximum value for all previous cycles, and 3) temporal interval between first and second maximums of cycle was 26 months that is second value from all 24 cycles. As to index of integral distribution of sunspot diameters, it was found earlier that this index α, in the average, equals about 6.0 for 7 previous cycles, in diameter range 50–90 Mm. New statistical analysis based on data for 2010–2015 allows to conclude that for 24th cycle α ≈ 5.8. Thus, dispersion of diameters of sunspots in 24th cycle is typical for majority of solar cycles.

  1. Background magnetic fields during last three cycles of solar activity

    NASA Astrophysics Data System (ADS)

    Andryeyeva, O. A.; Stepanian, N. N.

    2008-07-01

    This paper describes our studies of evolution of the solar magnetic field with different sign and field strength in the range from -100 G to 100 G. The structure and evolution of large-scale magnetic fields on the Sun during the last 3 cycles of solar activity is investigated using magnetograph data from the Kitt Peak Solar Observatory. This analysis reveals two groups of the large-scale magnetic fields evolving differently during the cycles. The first group is represented by relatively weak background fields, and is best observed in the range of 3-10 Gauss. The second group is represented by stronger fields of 75-100 Gauss. The spatial and temporal properties of these groups are described and compared with the total magnetic flux. It is shown that the anomalous behaviour of the total flux during the last cycle can be found only in the second group

  2. A double magnetic solar cycle and dynamical systems

    NASA Astrophysics Data System (ADS)

    Popova, H.

    Various solar activity data have indicated that along with the well-known 22-year cycle there is a shorter periodicity of about 2 years. To simulate this phenomenon, we constructed a dynamical system, which reproduced double-periodic behaviour of the solar cycle. Such nonlinear dynamical system described the solar αω-dynamo process with variable intensities Rα and Rω of the α-effect and the differential rotation, respectively. We have plotted the time distribution and butterfly diagrams for the poloidal and toroidal magnetic fields with dipole and quadrupole symmetries. The dynamical system with dipole symmetry of the magnetic field reproduces a regime similar to the double cycle at -450 < RαRω < -210. In the case of quadrupole symmetry, this regime exists at -220 < RαRω < -190.

  3. Solar neutron decay proton observations in cycle 21

    NASA Technical Reports Server (NTRS)

    Evenson, Paul; Kroeger, Richard; Meyer, Peter; Reames, Donald

    1990-01-01

    Measurement of the flux and energy spectrum of the protons resulting from the decay of solar flare neutrons gives unique information on the spectrum of neutrons from 5 to 200 MeV. Neutrons from three flares have been observed in this manner during solar cycle 21. The use of the decay protons to determine neutron energy spectra is reviewed, and new and definitive energy spectra are presented for the two large flares on June 3, 1982 and April 25, 1984.

  4. Investigation of X-ray and optical solar flare activities during solar cycles 22 and 23

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Bushueva, T. P.

    2003-02-01

    Daily X-ray flare indices (XFI) for the interval from January 1986 till June 2002 were calculated. The XFI behaviour during solar cycles 22 and 23 was studied. We compare the daily XFI with the daily optical flare indices (OFI) and with the International Relative Sunspot Numbers. The energy emitted by X-ray flares during 77 months of solar cycle 22 is shown to be about five times larger than the analogous value for the present solar cycle. We revealed statistically significant maxima in power spectra of the XFI and OFI. They correspond to periods of 25.5, 36.5, 73, 116, and 150d which presumably are appropriate to characteristic frequencies of the solar flare activity. A hypothesis on an possible effect of Mercury's variable electric charge on the origin of solar flares is proposed and corresponding estimates were made.

  5. The purple coloration of four late 19th century silk dresses: A spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Woodhead, Andrea L.; Cosgrove, Bronwyn; Church, Jeffrey S.

    2016-02-01

    Prior to the 19th century the use of purple dyes for textile coloration was expensive and usually limited to royalty. The discovery of several synthetic purple dyes during the 19th century made the production of purple textiles more affordable and thus more readily available. The identification of the source of the purple coloration is of historical interest. Small yarn samples from four late 19th century silk dresses were analyzed using a combination of thin layer chromatography and surface enhanced Raman spectroscopy, Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy. This combination of techniques enabled the analysis of the complex extraction products. While three of the dresses were found to be dyed using methyl violet, the fourth dress was found to be constructed from a warp yarn dyed with methyl violet in the presence of a tannic acid mordant, and a weft yarn dyed with mauve and a tin mordant.

  6. SOLAR ROTATION RATE DURING THE CYCLE 24 MINIMUM IN ACTIVITY

    SciTech Connect

    Antia, H. M.; Basu, Sarbani E-mail: sarbani.basu@yale.ed

    2010-09-01

    The minimum of solar cycle 24 is significantly different from most other minima in terms of its duration as well as its abnormally low levels of activity. Using available helioseismic data that cover epochs from the minimum of cycle 23 to now, we study the differences in the nature of the solar 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 solar dynamics, solar 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.

  7. A Statistical Test of Uniformity in Solar Cycle Indices

    NASA Technical Reports Server (NTRS)

    Hathaway David H.

    2012-01-01

    Several indices are used to characterize the solar activity cycle. Key among these are: the International Sunspot Number, the Group Sunspot Number, Sunspot Area, and 10.7 cm Radio Flux. A valuable aspect of these indices is the length of the record -- many decades and many (different) 11-year cycles. However, this valuable length-of-record attribute has an inherent problem in that it requires many different observers and observing systems. This can lead to non-uniformity in the datasets and subsequent erroneous conclusions about solar cycle behavior. The sunspot numbers are obtained by counting sunspot groups and individual sunspots on a daily basis. This suggests that the day-to-day and month-to-month variations in these numbers should follow Poisson Statistics and be proportional to the square-root of the sunspot numbers themselves. Examining the historical records of these indices indicates that this is indeed the case - even with Sunspot Area and 10.7 cm Radio Flux. The ratios of the RMS variations to the square-root of the indices themselves are relatively constant with little variation over the phase of each solar cycle or from small to large solar cycles. There are, however, important step-like changes in these ratios associated with changes in observer and/or observer system. Here we show how these variations can be used to construct more uniform datasets.

  8. Modeling the heliospheric current sheet: Solar cycle variations

    NASA Astrophysics Data System (ADS)

    Riley, Pete; Linker, J. A.; Mikić, Z.

    2002-07-01

    In this report we employ an empirically driven, three-dimensional MHD model to explore the evolution of the heliospheric current sheet (HCS) during the course of the solar cycle. We compare our results with a simpler ``constant-speed'' approach for mapping the HCS outward into the solar wind to demonstrate that dynamic effects can substantially deform the HCS in the inner heliosphere (<~5 AU). We find that these deformations are most pronounced at solar minimum and become less significant at solar maximum, when interaction regions are less effective. Although solar maximum is typically associated with transient, rather than corotating, processes, we show that even under such conditions, the HCS can maintain its structure over the course of several solar rotations. While the HCS may almost always be topologically equivalent to a ``ballerina skirt,'' we discuss an interval approaching the maximum of solar cycle 23 (Carrington rotations 1960 and 1961) when the shape would be better described as ``conch shell''-like. We use Ulysses magnetic field measurements to support the model results.

  9. Proceedings of the 19th International Conference on Ion Beam Modification of Materials (IBMM 2014)

    NASA Astrophysics Data System (ADS)

    Vantomme, André; Temst, Kristiaan

    2015-12-01

    It is our pleasure to present the proceedings of the 19th International Conference on Ion Beam Modification of Materials, which took place from September 14th until September 19th, 2014. The conference was held in the historic center of Leuven, a medieval city in the heart of Europe, a city where centuries-old culture meets frontier science and technology. Among other places, the conference brought us to the University Hall, which has been in use by the university since its foundation in 1425, to the Infirmerie of the Grand Beguinage and to the medieval city of Bruges, the latter two being Unesco World Heritage sites.

  10. Solar Cycle Variations and Equatorial Oscillations: Modeling Study

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Mengel, J. G.; Drob, D. P.; Chan, K. L.; Porter, H. S.; Bhartia, P. K. (Technical Monitor)

    2001-01-01

    Solar cycle activity effects (SCAE) in the lower and middle atmosphere, reported in several studies, are difficult to explain on the basis of the small changes in solar radiation that accompany the 11-year cycle, It is therefore natural to speculate that dynamical processes may come into play to produce a leverage. Such a leverage may be provided by the Quasi-Biennial Oscillation (QBO) in the zonal circulation of the stratosphere, which has been linked to solar activity variations. Driven primarily by wave mean flow interaction, the QBO period and its amplitude are variable but are also strongly influenced by the seasonal cycle in the solar radiation. This influence extends to low altitudes referred to as "downward control". Relatively small changes in solar radiative forcing can produce small changes in the period and phase of the QBO, but this in turn can produce measurable differences in the wind field. Thus, the QBO may be an amplifier of solar activity variations and a natural conduit of these variations to lower altitudes. To test this hypothesis, we conducted experiments with a 2D (two-dimensional) version of our Numerical Spectral Model that incorporates Hines' Doppler Spread Parameterization for small-scale gravity waves (GW). Solar cycle radiance variations (SCRV) are accounted for by changing the radiative heating rate on a logarithmic scale from 0.1 % at the surface to 1 % at 50 km to 10% at 100 km. With and without SCRV, but with the same GW flux, we then conduct numerical experiments to evaluate the magnitude of the SCAE in the zonal circulation. The numerical results indicate that, under certain conditions, the SCAE is significant and can extend to lower altitudes where the SCRV is inconsequential. At 20-km the differences in the modeled wind velocities are as large as 5 m/s. For a modeled QBO period of 30 months, we find that the seasonal cycle in the solar forcing (through the Semi-annual Oscillation (SAO)) acts as a strong pacemaker to lockup the

  11. BATSE flare observations in Solar Cycle 22

    NASA Technical Reports Server (NTRS)

    Schwartz, R. A.; Dennis, B. R.; Fishman, G. J.; Meegan, C. A.; Wilson, R. B.; Paciesas, W. S.

    1992-01-01

    The Hard X-Ray Burst Spectrometer (HXRBS) group at GSFC has developed and is maintaining a quick-look analysis system for solar flare hard x-ray data from the Burst and Transient Source Experiment (BATSE) on the recently launched Compton Gamma-Ray Observatory (GRO). The instrument consists, in part, of 8 large planar detectors, each 2025 sq cm, placed on the corners of the GRO spacecraft with the orientation of the faces being those of a regular octahedron. Although optimized for the detection of gamma-ray bursts, these detectors are far more sensitive than any previous spacecraft-borne hard x-ray flare instrumentation both for the detection of small microflares and the resolution of fine temporal structures. The data in this BATSE solar data base are from the discriminator large area (DISCLA) rates. From each of eight detectors there are hard x-ray data in four energy channels, 25-50, 50-100, 100-300, and greater than 300 keV with a time resolution of 1.024 seconds. These data are suitable for temporal correlation with data at other wavelengths, and they provide a first look into the BATSE and other GRO instrument flare data sets. The BATSE and other GRO principle investigator groups should be contacted for the availability of data sets at higher time or spectral resolution or at higher energies.

  12. Solar and interplanetary signatures of declining of solar magnetic fields: Implications to the next solar cycle 25

    NASA Astrophysics Data System (ADS)

    Bisoi, Susanta Kumar; Janardhan, P.; Ananthakrishnan, S.; Tokumaru, M.; Fujiki, K.

    2015-08-01

    Our detailed study of solar surface magnetic fields at high-latitudes, using magnetic synoptic magnetograms of NSO/Kitt Peak observatory from 1975-2014, has shown a steady decline of the field strength since mid-1990's until mid-2014, i.e. the solar maximum of cycle 24. We also found that magnetic field strength at high-latitudes declines after each solar cycle maximum, and since cycle 24 is already past its peak implies that solar surface magnetic fields will be continuing to decline until solar minimum of cycle 24. In addition, interplanetary scintillation (IPS) measurements of solar wind micro-turbulence levels, from Solar and Terrestrial Environment Laboratory (STEL), Japan, have also shown a steady decline in sync with the declining surface fields. Even the heliospheric magnetic fields (HMF) at 1 AU have been declined much below the previously proposed floor level of HMF of ~4.6 nT. From study of a correlation between the high-latitude surface fields and the HMF at the last four solar minima we found a floor value of HMF of ~3.2 nT. Using the above correlation and the fact that the high-latitude surface fields is expected to decline until the minimum of cycle 24, we estimate the value of the HMF at the minimum of cycle 24 will be 3.8 ± 0.2 nT and the peak sunspot number for solar cycle 25 will be 56±12 suggesting a weak sunspot activity to be continued in cycle 25 too.

  13. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    SciTech Connect

    Taylor, Robin; Davenport, Roger; Talbot, Jan; Herz, Richard; Genders, David; Symons, Peter; Brown, Lloyd

    2014-04-25

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are

  14. Mir Cooperative Solar Array Project Accelerated Life Thermal Cycling Test

    NASA Technical Reports Server (NTRS)

    Hoffman, David J.; Scheiman, David A.

    1996-01-01

    The Mir Cooperative Solar Array (MCSA) project was a joint U.S./Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA will be used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station. The MCSA was brought to Mir by space shuttle Atlantis in November 1995. This report describes an accelerated thermal life cycle test which was performed on two samples of the MCSA. In eight months time, two MCSA solar array 'mini' panel test articles were simultaneously put through 24,000 thermal cycles. There was no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early and removed from consideration. The nature of the performance degradation caused by this one cell is briefly discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the U.S. solar cell modules with the Russian support structure would be able to withstand at least 24,000 thermal cycles (4 years on-orbit). This was considered a successful development test.

  15. Correlation between solar acoustic emission and phase of the solar cycle

    NASA Astrophysics Data System (ADS)

    Chen, R.; Zhao, J.

    2015-12-01

    The solar acoustic emission is closely related to solar convection and magnetic field. Understanding the relation between the acoustic emission and the phase of a solar cycle is important to understand the dynamics of solar cycles and excitation of acoustic waves. In this work we use 4 years of SDO/HMI data from 05/2010 to 04/2014, covering the growing phase of the solar cycle 24, to study the acoustic emissions of the whole sun and of only the quiet sun regions respectively, at multiple frequency bands. We also analyze the correlations between the acoustic emissions and solar activity level indexed by daily sunspot number and magnetic flux. The results show that the correlation between the whole-sun acoustic emission and solar activity level is negative for low frequencies at 2.5-4.5 mHz, with a peak value around -0.9, and is positive for high frequencies at 4.5-6.0 mHz, with a peak value around 0.9. For high frequencies, the acoustic emission excess in sunspot halos overwhelms the emission deficiency in sunspot umbrae and penumbrae. The correlation between the quiet-sun acoustic emission and solar activity level is negative for 2.5-4.0 mHz and positive for 4.0-5.5 mHz, with peak values over ±0.8. This shows that the solar background acoustic power, with active regions excluded, is indeed varying during a solar cycle, implying the excitation frequencies or depths are highly related to the solar magnetic field.

  16. Variation of spring climate in lower-middle Yangtse River Valley and its relation with solar-cycle length

    SciTech Connect

    Hameed, S.; Gaofa Gong

    1994-12-01

    The relatively large number of historical records originating from the area of the Middle and Lower Yangtse River Valley in the late Ming dynasty and the Qing dynasty allows an estimation of the long term fluctuations of phenological dates. Dates of blossoming of plants, found in personal diaries and other documents, and used in this reconstruction are available, with some gaps, for 1580-1920. Independent estimates of spring conditions during the 18th century using data on last day of snowfall, and during 20th and late 19th centuries using accumulated temperatures in Shanghai are also presented. The results show that the spring weather in this region was colder than present in the 17th century and during 1790-1820 and 1870-1920. Spring temperature warmer than the present prevailed during 1720-1770 and 1840-1860. This variation agrees in its broad outline with that of the solar cycle length presented by Friis-Christensen and Lassen. 13 refs., 2 figs., 1 tab.

  17. Skin Cancer, Irradiation, and Sunspots: The Solar Cycle Effect

    PubMed Central

    Zurbenko, Igor

    2014-01-01

    Skin cancer is diagnosed in more than 2 million individuals annually in the United States. It is strongly associated with ultraviolet exposure, with melanoma risk doubling after five or more sunburns. Solar activity, characterized by features such as irradiance and sunspots, undergoes an 11-year solar cycle. This fingerprint frequency accounts for relatively small variation on Earth when compared to other uncorrelated time scales such as daily and seasonal cycles. Kolmogorov-Zurbenko filters, applied to the solar cycle and skin cancer data, separate the components of different time scales to detect weaker long term signals and investigate the relationships between long term trends. Analyses of crosscorrelations reveal epidemiologically consistent latencies between variables which can then be used for regression analysis to calculate a coefficient of influence. This method reveals that strong numerical associations, with correlations >0.5, exist between these small but distinct long term trends in the solar cycle and skin cancer. This improves modeling skin cancer trends on long time scales despite the stronger variation in other time scales and the destructive presence of noise. PMID:25126567

  18. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  19. Variations in the Sun's Meridional Flow Over a Solar Cycle

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Rightmire, Lisa

    2010-01-01

    The Sun's meridional flow is an axisymmetric flow that is generally directed from its equator toward its poles at the surface. The structure and strength of the meridional flow determine both the strength of the Sun's polar magnetic field and the intensity of sunspot cycles. We determine the meridional flow speed of magnetic features on the Sun using data from the Solar and Heliospheric Observatory. The average flow is poleward at all latitudes up to 75 , which suggests that it extends to the poles. It was faster at sun spot cycle minimum than at maximum and substantially faster on the approach to the current minimum than it was at the last solar minimum. This result may help to ex plain why this solar activity minimum is so peculiar.

  20. Variations of solar, interplanetary, and geomagnetic parameters with solar magnetic multipole fields during Solar Cycles 21-24

    NASA Astrophysics Data System (ADS)

    Kim, Bogyeong; Lee, Jeongwoo; Yi, Yu; Oh, Suyeon

    2015-01-01

    In this study we compare the temporal variations of the solar, interplanetary, and geomagnetic (SIG) parameters with that of open solar magnetic flux from 1976 to 2012 (from Solar Cycle 21 to the early phase of Cycle 24) for a purpose of identifying their possible relationships. By the open flux, we mean the average magnetic field over the source surface (2.5 solar radii) times the source area as defined by the potential field source surface (PFSS) model of the Wilcox Solar Observatory (WSO). In our result, most SIG parameters except the solar wind dynamic pressure show rather poor correlations with the open solar magnetic field. Good correlations are recovered when the contributions from individual multipole components are counted separately. As expected, solar activity indices such as sunspot number, total solar irradiance, 10.7 cm radio flux, and solar flare occurrence are highly correlated with the flux of magnetic quadrupole component. The dynamic pressure of solar wind is strongly correlated with the dipole flux, which is in anti-phase with Solar Cycle (SC). The geomagnetic activity represented by the Ap index is correlated with higher order multipole components, which show relatively a slow time variation with SC. We also found that the unusually low geomagnetic activity during SC 23 is accompanied by the weak open solar fields compared with those in other SCs. It is argued that such dependences of the SIG parameters on the individual multipole components of the open solar magnetic flux may clarify why some SIG parameters vary in phase with SC and others show seemingly delayed responses to SC variation.

  1. Cycle Length Dependence of Stellar Magnetic Activity and Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Choi, Hwajin; Lee, Jeongwoo; Oh, Suyeon; Kim, Bogyeong; Kim, Hoonkyu; Yi, Yu

    2015-03-01

    Solar cycle (SC) 23 was extraordinarily long with remarkably low magnetic activity. We have investigated whether this is a common behavior of solar-type stars. From the Ca ii H and K line intensities of 111 stars observed at Mount Wilson Observatory from 1966 to 1991, we have retrieved data of all 23 G-type stars and recalculated their cycle lengths using the damped least-squares method for the chromospheric activity index S as a function of time. A regression analysis was performed to find relations between the derived cycle length, Pavg, and the index for excess chromospheric emission, RHK\\prime . As a noteworthy result, we found a segregation between young and old solar-type stars in the cycle length-activity correlation. We incorporated the relation for the solar-type stars into the previously known rule for stellar chromospheric activity and brightness to estimate the variation of solar brightness from SC 22 to SC 23 as (0.12 ± 0.06)%, much higher than the actual variation of total solar irradiance (TSI) ≤0.02%. We have then examined solar spectral irradiance (SSI) to find a good phase correlation with a sunspot number in the wavelength range of 170-260 nm, which is close to the spectral range effective in heating the Earth’s atmosphere. Therefore, it appears that SSI rather than TSI is a good indicator of the chromospheric activity, and its cycle length dependent variation would be more relevant to the possible role of the Sun in the cyclic variation of the Earth’s atmosphere.

  2. Solar large-scale positive polarity magnetic fields and geomagnetic disturbances

    NASA Technical Reports Server (NTRS)

    Bumba, V.

    1972-01-01

    Unlike the negative polarity solar magnetic field large-scale regular features that correlate with enhanced solar activity regions, the positive polarity regular formations formed in the weak and old background magnetic fields seem to correlate well with geomagnetically enhanced periods of time (shifted for 4 days), which means that they seem to be the source of the quiet solar wind. This behavior of the large intervals of heliographic longitude with prevailing positive polarity fields may be followed to the end of the 18th cycle, during the declining part of the 19th cycle, and during the first half of the present 20th cycle of solar activity.

  3. [Foods and drinks in a 19th century human physiology textbook].

    PubMed

    Chiancone, Francesco M

    2004-01-01

    The Author reports on the chapter of "Nutrition" in the Human Physiology textbook by P. Albertoni and A. Stefani published in the first half of the 19th century. This is one of the first textbooks that treats Physiology as an experimental science in contrast with the thinking of the previous century which was still dominated by Galen and Dioscorides.

  4. Missionaries and Tonic Sol-fa Music Pedagogy in 19th-Century China

    ERIC Educational Resources Information Center

    Southcott, Jane E.; Lee, Angela Hao-Chun

    2008-01-01

    In the 19th century, Christian missionaries in China, as elsewhere, used the Tonic Sol-fa method of music instruction to aid their evangelizing. This system was designed to improve congregational singing in churches, Sunday schools and missions. The London Missionary Society and other evangelical groups employed the method. These missionaries took…

  5. 5. Photocopy, GENERAL VIEW OF FORT TOTTEN, LOOKING NORTHWEST, mid19th ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photocopy, GENERAL VIEW OF FORT TOTTEN, LOOKING NORTHWEST, mid-19th century. Original photograph at State Historical Society of North Dakota, file No. B 37 - Fort Totten, 12 miles southwest of Devils Lake City off Route 57, Devils Lake, Ramsey County, ND

  6. The Romantic Rhetoric of 19th Century Obituaries: "She Gave a Few Faint Gasps and Died."

    ERIC Educational Resources Information Center

    Agnew, Eleanor

    Scholars of writing, language, and culture will find a rich fund of research material in 19th-century obituaries which convey extensive details of the deceased's life through an elegant language reminiscent of an oral culture. In contrast to today's newspaper obituaries, which are business-like, tight-lipped, and entirely devoid of any details or…

  7. An Analysis of Environmental Issues in 19th Century England Using the Writings of Charles Dickens

    ERIC Educational Resources Information Center

    MacKenzie, Ann Haley

    2008-01-01

    Charles Dickens lived during the best and worst of times in 19th century England. His writings were greatly influenced by the ongoing industrial revolution. He described abhorrent environmental conditions, inadequate sanitary practices, child abuse, and other social maladies of the times. By bringing Charles Dickens into the biology classroom,…

  8. Circumcision of the Female Intellect: 19th Century Women Who Opposed Scholarly Education

    ERIC Educational Resources Information Center

    Holmes, Marbeth

    2009-01-01

    In 19th century America, some women decried the opportunity for scholarly education as rebellion against religion and predicted a grim decline in the quality of life, home, and hearth for American families and for American culture and politics. In particular, women who opposed scholarly education argued that God had not created men and women…

  9. The Rise of Age Homogamy in 19th Century Western Europe

    ERIC Educational Resources Information Center

    van de Putte, Bart; Van Poppel, Frans; Vanassche, Sofie; Sanchez, Maria; Jidkova, Svetlana; Eeckhaut, Mieke; Oris, Michel; Matthijs, Koen

    2009-01-01

    In many parts of Western Europe the age at first marriage and the level of celibacy declined in the second half of the 19th century. This weakening of the European marriage pattern (EMP) can be interpreted as a "classic" response to the increase of the standard of living, but a more far-reaching interpretation is that the erosion of the…

  10. Japanese Concepts of Child Development from the Mid-17th to Mid-19th Century.

    ERIC Educational Resources Information Center

    Kojima, Hideo

    1986-01-01

    Summarizes beliefs and values about child rearing from documents written by experts on the mid-17th to mid-19th centuries. The experts argued that children are innately good rather than evil; environmental factors accounted for differences among children rather than innate factors; and children were autonomous rather than passive learners. (HOD)

  11. The Garbers: Using Digital History To Recreate a 19th-Century Family.

    ERIC Educational Resources Information Center

    Mason, Cheryl L.; Carter, Alice

    1999-01-01

    Describes a lesson in which students read a letter from the Web site "Valley of the Shadow: Two Communities during the American Civil War," an interactive archive of digitized primary sources. Students search the site's 1860 population census to learn about Thomas Garber and his family. Students also learn about life in the 19th century.…

  12. Seriously Popular: Rethinking 19th-Century American Literature through the Teaching of Popular Fiction

    ERIC Educational Resources Information Center

    Gatti, Lauren

    2011-01-01

    Curious about the connections between the author's students' reading tastes and those of 19th-century readers, the author read Nina Baym's excellent text "Novels, Readers, and Reviewers: Responses to Fiction in Antebellum America" to gain a sense of how readers in the 1800s might have thought about the texts that they read. Nineteenth-century…

  13. MOSQUITO VECTOR CONTROL AND BIOLOGY IN LATIN AMERICA - A 19TH SYMPOSIUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 19th Annual Latin American symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 75th Annual Meeting in New Orleans, LA, in April 2009. The principal objective, as for the previous 18 symposia, was to promote participation in the AMCA by vector control s...

  14. Pacific Telecommunications Council Annual Conference Proceedings (19th, Honolulu, Hawaii, January 19-22, 1997).

    ERIC Educational Resources Information Center

    Wedemeyer, Dan J., Ed.; Nickelson, Richard, Ed.

    This PTC'97 volume contains papers presented at the 19th annual conference of the Pacific Telecommunications Council, "Pacific Connections: Policy and Technology in the Information Economy" (1997). Three super-session groupings--industry, policy, and technology--provide attendees with a conceptual foundation from which subsequent…

  15. 1. COPY OF A LATE 19TH CENTURY BUSINESS CARD FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. COPY OF A LATE 19TH CENTURY BUSINESS CARD FOR A. ALEXANDER & SON FLOURING MILLS. CARD OWNED BY THOMAS R. WILSON. Photographer: Berni Rich, Score Photographers, September 1986. - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

  16. Negative Numbers in the 18th and 19th Centuries: Phenomenology and Representations

    ERIC Educational Resources Information Center

    Maz-Machado, Alexander; Rico-Romero, Luis

    2009-01-01

    This article presents a categorization of the phenomena and representations used to introduce negative numbers in mathematics books published in Spain during the 18th and 19th centuries. Through a content analysis of fourteen texts which were selected for the study, we distinguished four phenomena typologies: physical, accounting, temporal and…

  17. Dancetime! 500 Years of Social Dance. Volume I: 15th-19th Centuries. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This VHS videotape recording is the first in a two-volume series that presents 500 years of social dance, music, and fashion. It focuses on the 15th-19th centuries, including Renaissance nobility, Baroque extravagance, Regency refinement, and Victorian romanticism. Each era reflects the changing relationships between men and women through the…

  18. [Rape and transgression. Forensic medicine and sexual morality in Spain in the 19th century].

    PubMed

    Carpena, Amalio Lorente

    2010-01-01

    The purpose of this paper is to analyse the importance of the contribution of the Spanish forensic medical discourse in the 19th century, and its application in cases of sexual harassment, to legitimize the sexual moral value of the time. For that reason we will analyse the main forensic medicine treaties edited in Spain during this century.

  19. SOLAR MAGNETIC HELICITY INJECTED INTO THE HELIOSPHERE: MAGNITUDE, BALANCE, AND PERIODICITIES OVER SOLAR CYCLE 23

    SciTech Connect

    Georgoulis, M. K.; Rust, D. M.; Bernasconi, P. N.; Pevtsov, A. A.; Kuzanyan, K. M.

    2009-11-01

    Relying purely on solar photospheric magnetic field measurements that cover most of solar cycle 23 (1996-2005), we calculate the total relative magnetic helicity injected into the solar atmosphere, and eventually shed into the heliosphere, over the latest cycle. Large active regions dominate the helicity injection process with approx5.7 x 10{sup 45} Mx{sup 2} of total injected helicity. The net helicity injected is approx<1% of the above output. Peculiar active-region plasma flows account for approx80% of this helicity; the remaining approx20% is due to solar differential rotation. The typical helicity per active-region CME ranges between (1.8-7) x 10{sup 42} Mx{sup 2} depending on the CME velocity. Accounting for various minor underestimation factors, we estimate a maximum helicity injection of approx6.6 x 10{sup 45} Mx{sup 2} for solar cycle 23. Although no significant net helicity exists over both solar hemispheres, we recover the well-known hemispheric helicity preference, which is significantly enhanced by the solar differential rotation. We also find that helicity injection in the solar atmosphere is an inherently disorganized, impulsive, and aperiodic process.

  20. No link between the solar activity cycle and the diameter

    NASA Astrophysics Data System (ADS)

    Dame, L.; Cugnet, D.

    We do not understand the physical mechanisms responsible for the solar irradiance cycle. Measurements of small variations in the solar diameter could have been a critical probe of the Sun 's interior stratification, telling us how and where the solar luminosity is gated or stored. We have reanalyzed the 7 years of filtregrams data (150 000 photograms and magnetograms) of the SOHO/MDI experiment. We used the maximum possible sampling compatible with full frame recording, carefully avoiding any suspicious filtregram. Going further than the previous analysis of 2 years of data by Emilio et al. (Ap. J. 543,1007, 2000), we better corrected for changes in optical aberrations and, along Turmon et al. (Ap. J., 568, 396, 2002), we reduced radius measurement errors by identifying active regions and avoiding radius measurements herein. We found that, within the limit of our noise level uncertainties (2 mas), the solar diameter could be constant over the half cycle investigated. Our results confirm the recent reanalysis of the 7 years of MDI data made by Antia (Ap. J. 590, 567, 2003), with a completely different method since using the ultra-precise frequency variation of the f-modes (fundamental modes linked to the diameter). He found (carefully removing the yearly Earth induced variations and avoiding the SOHO data gap of 1999) that the diameter is constant over the half solar cycle (radius variation are less than 0.6 km, 0.8 mas - nothing over noise level). Along Antia, we can conclude that: "If a careful analysis is performed, then it turns out that there is no evidence for any variation in the solar radius." There were no theoretical reasons for large solar radius variations and there is no observational evidence for them with consistent space observations. If changes exit, they are to be very small.

  1. Solar cycle dependence of Wind/EPACT protons, solar flares and coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Miteva, R.; Samwel, S. W.; Costa-Duarte, M. V.; Malandraki, O. E.

    2017-01-01

    The aim of this work is to compare the occurrence and overall properties of solar energetic particles (SEPs), solar flares and coronal mass ejections (CMEs) over the first seven years in solar cycles (SCs) 23 and 24. For the case of SEP events, we compiled a new proton event catalog using data from the Wind/EPACT instrument. We confirm the previously known reduction of high energy proton events in SC24 compared to the same period in SC23; our analysis shows a decrease of 25-50 MeV protons by about 30%. The similar trend is found for X to C-class solar flares which are less by about 40% and also for faster than 1000 km/s CMEs, which are reduced by about 45%. In contrast, slow CMEs are more numerous in the present solar cycle. We discuss the implications of these results for the population of SEP-productive flares and CMEs.

  2. Solar hydrogen Lyman-α variation during solar cycles 21 and 22

    NASA Astrophysics Data System (ADS)

    Kent Tobiska, W.; Pryor, Wayne R.; Ajello, Joseph M.

    1997-05-01

    A full-disk, line-integrated solar Lyman-α dataset is presented that spans two solar cycles. The dataset is created partially from AE-E and SME data that is scaled to the Pioneer Venus Orbiter Ultraviolet Spectrometer (PVOUVS) upwind Lyman-α sky background data which is converted to a solar surrogate. PVOUVS measurements overlap AE-E, SME, and UARS observing periods and are calibrated to UARS/SOLSTICE irradiance units at 1 AU. The scaled AE-E/SME, the SOLSTICE, and the PVOUVS surrogate data in the interim between the satellites collectively form a composite dataset with a quiet sun value of 3.0+/-0.1×1011 photons cm-2s-1 common for three solar minima and a solar maximum value of 6.75+/-0.25×1011 photons cm-2s-1 common to cycles 21 and 22.

  3. Solar hydrogen Lyman-α variation during solar cycles 21 and 22

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Pryor, Wayne R.; Ajello, Joseph M.

    1997-05-01

    A full-disk, line-integrated solar Lyman-α dataset is presented that spans two solar cycles. The dataset is created partially from AE-E and SME data that is scaled to the Pioneer Venus Orbiter Ultraviolet Spectrometer (PVOUVS) upwind Lyman-α sky background data which is converted to a solar surrogate. PVOUVS measurements overlap AE-E, SME, and UARS observing periods and are calibrated to UARS/SOLSTICE irradiance units at 1 AU. The scaled AE-E/SME, the SOLSTICE, and the PVOUVS surrogate data in the interim between the satellites collectively form a composite dataset with a quiet sun value of 3.0±0.1 × 1011 photons cm-2s-1 common for three solar minima and a solar maximum value of 6.75±0.25 × 1011 photons cm-2s-1 common to cycles 21 and 22.

  4. 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.

  5. Observed Helicity of Active Regions in Solar Cycle 21

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.; Pevtsov, A. A.; Blehm, Z.; Smith, J. E.; Six, Frank (Technical Monitor)

    2003-01-01

    We report the results of a study of helicity in solar active regions during the peak of activity in solar cycle 21 from observations with the Marshall Space Flight Center's solar vector magnetograph. Using the force-free parameter alpha as the proxy for helicity, we calculated an average value of alpha for each of 60 active regions from a total of 449 vector magnetograms that were obtained during the period 1980 March to November. The signs of these average values of alpha were correlated with the latitude of the active regions to test the hemispheric rule of helicity that has been proposed for solar magnetic fields: negative helicity predominant in northern latitudes, positive in the southern ones. We have found that of the 60 regions that were observed, 30 obey the hemispheric rule and 30 do not.

  6. Solar powered Stirling cycle electrical generator

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.

    1991-01-01

    Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is developing the technology needed for free-piston Stirling engines as a candidate power source for space systems in the late 1990's and into the next century. Space power requirements include high efficiency, very long life, high reliability, and low vibration. Furthermore, system weight and operating temperature are important. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, non-contacting gas bearings, and can be hermetically sealed. These attributes of the free-piston Stirling engine also make it a viable candidate for terrestrial applications. In cooperation with the Department of Energy, system designs are currently being completed that feature the free-piston Stirling engine for terrestrial applications. Industry teams were assembled and are currently completing designs for two Advanced Stirling Conversion Systems utilizing technology being developed under the NASA CSTI Program. These systems, when coupled with a parabolic mirror to collect the solar energy, are capable of producing about 25 kW of electricity to a utility grid. Industry has identified a niche market for dish Stirling systems for worldwide remote power application. They believe that these niche markets may play a major role in the introduction of Stirling products into the commercial market.

  7. Solar panel thermal cycling testing by solar simulation and infrared radiation methods

    NASA Technical Reports Server (NTRS)

    Nuss, H. E.

    1980-01-01

    For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

  8. Effects of Low Activity Solar Cycle on Orbital Debris Lifetime

    NASA Technical Reports Server (NTRS)

    Cable, Samual B.; Sutton, Eric K.; Lin, chin S.; Liou, J.-C.

    2011-01-01

    Long duration of low solar activity in the last solar 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 solar activity with neutral density models, drag coefficient models, and an orbit propagator to predict satellite lifetime. We run the OEP model with solar indices forecast by the NASA Marshall Solar Activity 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 activity solar 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 solar flux on the orbital debris population in the 200-600 km altitude environment. The results are discussed for developing satellite orbital drag application product.

  9. Longitudinal Waves Drive the Solar Cycle

    NASA Astrophysics Data System (ADS)

    Wagner, Orvin

    2000-05-01

    In Physics Essays 12: 3-10 I explain the placement of the planets in terms of low velocity waves emitted by the sun. Evidence for the wave pulse generated near the center of the sun is indicated by the initial high latitude sunspots observed on the butterfly diagram. The wave pulse carries charge with it as observed for similar waves in plants (W-waves). For the first half cycle negative charge is carried to the surface of the sun where much of the wave pulse radiates a wave crest into space while the charge slowly redistributes itself. Meanwhile the next wave pulse carrying excess positive charge moves outward. Rotating charge determines the polarity of the sun's magnetic poles so they reverse as the pulse moves outward. The wave pulse, which interacts strongly with force fields, is guided by centripetal force and gravity so that the pulse comes out near the sun's equator. W-waves produce an automatic return wave in the vacuum so that standing waves are produced in the space around the sun providing a template for the formation and stabilization planets. W-waves are hypothesized to provide self organization for both the universe and life. See the

  10. Nonlinear data assimilation: towards a prediction of the solar cycle

    NASA Astrophysics Data System (ADS)

    Svedin, Andreas

    The solar cycle is the cyclic variation of solar activity, with a span of 9-14 years. The prediction of the solar cycle is an important and unsolved problem with implications for communications, aviation and other aspects of our high-tech society. Our interest is model-based prediction, and we present a self-consistent procedure for parameter estimation and model state estimation, even when only one of several model variables can be observed. Data assimilation is the art of comparing, combining and transferring observed data into a mathematical model or computer simulation. We use the 3DVAR methodology, based on the notion of least squares, to present an implementation of a traditional data assimilation. Using the Shadowing Filter — a recently developed method for nonlinear data assimilation — we outline a path towards model based prediction of the solar cycle. To achieve this end we solve a number of methodological challenges related to unobserved variables. We also provide a new framework for interpretation that can guide future predictions of the Sun and other astrophysical objects.

  11. Central antarctic climate response to the solar cycle

    NASA Astrophysics Data System (ADS)

    Volobuev, D. M.

    2014-05-01

    Antarctic "Vostok" station works most closely to the center of the ice cap among permanent year-around stations. Climate conditions are exclusively stable: low precipitation level, cloudiness and wind velocity. These conditions can be considered as an ideal model laboratory to study the surface temperature response on solar irradiance variability during 11-year cycle of solar activity. Here we solve an inverse heat conductivity problem: calculate the boundary heat flux density (HFD) from known evolution of temperature. Using meteorological temperature record during (1958-2011) we calculated the HFD variation about 0.2-0.3 W/m2 in phase with solar activity cycle. This HFD variation is derived from 0.5 to 1 °C temperature variation and shows relatively high climate sensitivity per 0.1 % of solar radiation change. This effect can be due to the polar amplification phenomenon, which predicts a similar response 0.3-0.8 °C/0.1 % (Gal-Chen and Schneider in Tellus 28:108-121, 1975). The solar forcing (TSI) is disturbed by volcanic forcing (VF), so that their linear combination TSI + 0.5VF empirically provides higher correlation with HFD (r = 0.63 ± 0.22) than TSI (r = 0.50 ± 0.24) and VF (r = 0.41 ± 0.25) separately. TSI shows higher wavelet coherence and phase agreement with HFD than VF.

  12. Thermal Cycling of Mir Cooperative Solar Array (MCSA) Test Panels

    NASA Technical Reports Server (NTRS)

    Hoffman, David J.; Scheiman, David A.

    1997-01-01

    The Mir Cooperative Solar Array (MCSA) project was a joint US/Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA is currently being used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station (ISS), which will use arrays based on the same solar cells used in the MCSA. The US supplied the photovoltaic power modules (PPMs) and provided technical and programmatic oversight while Russia provided the array support structures and deployment mechanism and built and tested the array. In order to ensure that there would be no problems with the interface between US and Russian hardware, an accelerated thermal life cycle test was performed at NASA Lewis Research Center on two representative samples of the MCSA. Over an eight-month period (August 1994 - March 1995), two 15-cell MCSA solar array 'mini' panel test articles were simultaneously put through 24,000 thermal cycles (+80 C to -100 C), equivalent to four years on-orbit. The test objectives, facility, procedure and results are described in this paper. Post-test inspection and evaluation revealed no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early as an artifact of the test and removed from consideration. The interesting nature of the performance degradation caused by this one cell, which only occurred at elevated temperatures, is discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the US solar cell modules with the Russian support structure would be able to withstand at least 24,000 thermal cycles (4 years on-orbit).

  13. Thermal cycling of Mir Cooperative Solar Array (MCSA) test panels

    SciTech Connect

    Hoffman, D.J.; Scheiman, D.A.

    1997-12-31

    The Mir Cooperative Solar Array (MCSA) project was a joint US/Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA is currently being used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station (ISS), which will use arrays based on the same solar cells used in the MCSA. The US supplied the photovoltaic power modules (PPMs) and provided technical and programmatic oversight while Russia provided the array support structures and deployment mechanism and built and tested the array. In order to ensure that there would be no problems with the interface between US and Russian hardware, an accelerated thermal life cycle test was performed at NASA Lewis Research Center on two representative samples of the MCSA. Over an eight-month period (August 1994--March 1995), two 15-cell MCSA solar array mini panel test articles were simultaneously put through 24000 thermal cycles (+80 C to {minus}100 C), equivalent to four years on-orbit. The test objectives, facility, procedure and results are described in this paper. Post-test inspection and evaluation revealed no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early as an artifact of the test and removed from consideration. The interesting nature of the performance degradation caused by this one cell, which only occurred at elevated temperatures, is discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the US solar cell modules with the Russian support structure would be able to withstand at least 24000 thermal cycles (4 years on-orbit).

  14. Solar cycle variations in the powers and damping rates of low-degree solar acoustic oscillations

    NASA Astrophysics Data System (ADS)

    Broomhall, A.-M.; Pugh, C. E.; Nakariakov, V. M.

    2015-12-01

    Helioseismology uses the Sun's natural resonant oscillations to study the solar interior. The properties of the solar oscillations are sensitive to the Sun'2019;s magnetic activity cycle. Here we examine variations in the powers, damping rates, and energy supply rates of the most prominent acoustic oscillations in unresolved, Sun-as-a-star data, obtained by the Birmingham Solar Oscillations Network (BiSON) during solar cycles 22, 23, and the first half of 24. The variations in the helioseismic parameters are compared to the 10.7 cm flux, a well-known global proxy of solar activity. As expected the oscillations are most heavily damped and the mode powers are at a minimum at solar activity maximum. The 10.7 cm flux was linearly regressed using the fractional variations of damping rates and powers observed during cycle 23. In general, good agreement is found between the damping rates and the 10.7 cm flux. However, the linearly regressed 10.7 cm flux and fractional variation in powers diverge in cycles 22 and 24, indicating that the relationship between the mode powers and the 10.7 cm flux is not consistent from one cycle to the next. The energy supply rate of the oscillations, which is usually approximately constant, also decreases at this time. We have determined that this discrepancy is not because of the first-order bias introduced by an increase in the level of background noise or gaps in the data. Although we cannot categorically rule out an instrumental origin, the divergence observed in cycle 24, when the data were of high quality and the data coverage was over 80%, raises the possibility that the effect may be solar in origin.

  15. A Possible Cause of the Diminished Solar Wind During the Solar Cycle 23 - 24 Minimum

    NASA Astrophysics Data System (ADS)

    Liou, Kan; Wu, Chin-Chun

    2016-12-01

    Interplanetary magnetic field and solar wind plasma density observed at 1 AU during Solar Cycle 23 - 24 (SC-23/24) minimum were significantly smaller than those during its previous solar cycle (SC-22/23) minimum. Because the Earth's orbit is embedded in the slow wind during solar minimum, changes in the geometry and/or content of the slow wind region (SWR) can have a direct influence on the solar wind parameters near the Earth. In this study, we analyze solar wind plasma and magnetic field data of hourly values acquired by Ulysses. It is found that the solar wind, when averaging over the first (1995.6 - 1995.8) and third (2006.9 - 2008.2) Ulysses' perihelion ({˜} 1.4 AU) crossings, was about the same speed, but significantly less dense ({˜} 34 %) and cooler ({˜} 20 %), and the total magnetic field was {˜} 30 % weaker during the third compared to the first crossing. It is also found that the SWR was {˜} 50 % wider in the third ({˜} 68.5^deg; in heliographic latitude) than in the first ({˜} 44.8°) solar orbit. The observed latitudinal increase in the SWR is sufficient to explain the excessive decline in the near-Earth solar wind density during the recent solar minimum without speculating that the total solar output may have been decreasing. The observed SWR inflation is also consistent with a cooler solar wind in the SC-23/24 than in the SC-22/23 minimum. Furthermore, the ratio of the high-to-low latitude photospheric magnetic field (or equatorward magnetic pressure force), as observed by the Mountain Wilson Observatory, is smaller during the third than the first Ulysses' perihelion orbit. These findings suggest that the smaller equatorward magnetic pressure at the Sun may have led to the latitudinally-wider SRW observed by Ulysses in SC-23/24 minimum.

  16. Solar Cycle comparison of Nitric Oxide in the lower thermosphere

    NASA Astrophysics Data System (ADS)

    Carstens, P. L.; Bailey, S. M.; Thurairajah, B.; Yonker, J. D.; Venkataramani, K.; Russell, J. M.; Hervig, M. E.

    2013-12-01

    Nitric oxide (NO) is a key minor constituent in the lower thermosphere. Of particular importance is its role in the energy balance in that altitude region. NO is produced through the reaction of excited atomic nitrogen with molecular oxygen. Thus, its production is very sensitive to those energy sources able to break the strong molecular nitrogen bond. These include solar soft X-rays and precipitating energetic particles. NO emits efficiently in the infrared and is an important cooling mechanism in the lower thermosphere. The abundance of NO is thus both a direct response to recent energy deposition as well as a key mechanism by which the upper atmosphere releases that energy. The concentration of NO should show a close relation to solar energy input. In this poster, we analyze the NO observations from the Solar Occultation for Ice Experiment (SOFIE) instrument. The SOFIE instrument was launched on-board the Aeronomy of Ice in the Mesosphere (AIM) satellite on April 25, 2007. It is currently in its sixth year of operation. SOFIE is a 16 channel differential absorption radiometer using the solar occultation technique to measure ice and environmental properties at a range of altitudes, and in particular the mesopause region. One of the constituents measured by SOFIE is NO in the mesosphere and lower thermosphere to about 130 km. The AIM orbit and the solar occultation technique confine observations to latitudes of 65 to 85 degrees in each hemisphere and varying with season. Here, we present the SOFIE observations and discuss its relationship with current levels of solar X-ray irradiance. We will further estimate the change in NO concentration (mixing ratios and densities) for the previous and current solar minimum. The statistics for this change will be presented for northern, equatorial and southern latitudes. We take the period of Jul 2008 - Jun 2009 to represent the current solar minimum between the solar cycles 23 and 24 and the period of Jan - Dec 1996 to

  17. Comparison of Voyager Shocks in Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Ashmall, Justin; Richardson, John

    2005-08-01

    Solar cycle 23 was notable for two periods of intense solar activity (or `events' as we shall hereafter refer to them): the `Bastille Day Event' of 2000 and the `Halloween Event' of 2003. In this paper we look at the signatures of the interplanetary shocks produced by these events, in particular the plasma parameters, as observed by Voyager 2 (V2) some six months after the events occurred at Sun. We compare these shocks with other large events observed by V2 during the preceding decade. We note that the plasma parameters, most notably the plasma density, are frequently not as might be expected for ``typical'' events.

  18. An 'extended Solar CYCLE` as Observed in fe XIV

    NASA Astrophysics Data System (ADS)

    Altrock, Richard C.

    1997-02-01

    Investigation of the behavior of coronal intensity above the limb in Fe XIV emission (530.3 nm) obtained at the National Solar Observatory at Sacramento Peak over the last 23 years has resulted in the confirmation of a second set of zones of solar activity at high latitudes, separate from the Main Activity Zones (MAZ). Localized high-latitude intensity maxima, which I will call High-latitude Emission Features (HEF), are observed at 0.15 solar radii above the limb throughout the solar cycle. They persist long enough at a given latitude to be visible in long-term (e.g., annual) averages. I identify two types of HEF. Poleward-moving HEF, which may be identified with the "Rush to the Poles" phenomenon seen in polar-crown prominences, were first seen to appear in this investigation near latitude 60 degrees in 1978. In 1979 equatorward-moving HEF branched off from the poleward-moving HEF (which continued on to reach the pole in 1980) at a latitude of 70 to 80 degrees. They evolved approximately parallel to the MAZ. Near solar minimum, these HEF evolved into the MAZ of Cycle 22, and the emission continues its path towards the equator, where it should disappear soon. Currently, it is clear that the pattern seen earlier is repeating. The poleward-moving HEF became apparent near the beginning of 1988 near 50 to 60 degrees latitude. The northern poleward-moving HEF reached the pole and disappeared in 1990. The southern poleward-moving HEF moved more slowly, reaching the pole and disappearing in 1991. The equatorward-moving HEF that are the precursors of Cycle 23 appeared in 1989 to 1990 and began to move approximately parallel to the MAZ of Cycle 22. Based on inferences from previous Cycles, we can expect these HEF to continue to the equator, with emission ceasing there near 2009. These recent observations increase the evidence for an "Extended" Solar Cycle that begins every 11 years but lasts for approximately 19-20 years.

  19. Solar Cycle Variation and Multipoint Studies of ICME Properties

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    2005-01-01

    The goal of the Living With a Star program is to understand the Sun-Earth connection sufficiently well that we can solve problems critical to life and society. This can most effectively be done in the short term using observations from our past and on-going programs. Not only can this approach solve some of the pressing issues but also it can provide ideas for the deployment of future spacecraft in the LWS program. The proposed effort uses data from NEAR, SOHO, Wind, ACE and Pioneer Venus in quadrature, multipoint, and solar cycle studies to study the interplanetary coronal mass ejection and its role in the magnetic flux cycle of the Sun. ICMEs are most important to the LWS objectives because the solar wind conditions associated with these structures are the most geoeffective of any solar wind phenomena. Their ability to produce strong geomagnetic disturbances arises first because of their high speed. This high speed overtakes the ambient solar wind producing a bow shock wave similar to the terrestrial bow shock. In the new techniques we develop as part of this effort we exploit this feature of ICMEs. This shocked plasma has a greater velocity, higher density and stronger magnetic field than the ambient solar wind, conditions that can enhance geomagnetic activity. The driving ICME is a large magnetic structure expanding outward in the solar wind [Gosling, 19961. The ICMEs magnetic field is generally much higher than that in the ambient solar wind and the velocity is high. The twisted nature of the magnetic field in an ICME almost ensures that sometime during the ICME conditions favorable for geomagnetic storm initiation will occur.

  20. Preliminary prediction of the 25-thTH solar cycle parameters

    NASA Astrophysics Data System (ADS)

    Pishkalo, M.

    2014-12-01

    Solar activity varies with a period of about 11 years. The solar activity variations cause changes in the interplanetary and near-Earth space. The whole space weather is mainly controlled by the solar activity. Changes in space weather affect the operation of space-borne and ground-based technological systems such as manned space flights, aero-navigation and space navigation, radars, high-frequency radio communication, GPS navigation, ground power lines. The solar activity variations influence living organisms and the climate on Earth. That is why it is important to know the level of solar activity in a solar cycle in advance. Current solar activity is near the maximum of solar cycle 24. Maximal monthly sunspot number was 102.8 in February 2014 and smoothed one was 75.4 in November 2013 (preliminary). Taking it into account and using correlation relations and regression equations from (Pishkalo, 2014: Solar Phys., vol. 289, 1815) we can estimate duration of solar cycle 24 and then predict parameters of solar cycle 25. Precursors in our calculations are the estimated duration of solar cycle 24 and sunspot number at the end of the cycle. We found that minimum and maximum of solar cycle 25 in monthly sunspot numbers will amount to 5 in April–June of 2020 and 105–110 in October–December of 2024, respectively. Solar cycle 25 will be stronger than the current cycle 24. No very deep drop in solar activity similar to Dalton or Maunder minimums was predicted.

  1. The onset of the solar active cycle 22

    NASA Technical Reports Server (NTRS)

    Ahluwalia, H. S.

    1989-01-01

    There is a great deal of interest in being able to predict the main characteristics of a solar activity cycle (SAC). One would like to know, for instance, how large the amplitude (R sub m) of a cycle is likely to be, i.e., the annual mean of the sunspot numbers at the maximum of SAC. Also, how long a cycle is likely to last, i.e., its period. It would also be interesting to be able to predict the details, like how steep the ascending phase of a cycle is likely to be. Questions like these are of practical importance to NASA in planning the launch schedule for the low altitude, expensive spacecrafts like the Hubble Space Telescope, the Space Station, etc. Also, one has to choose a proper orbit, so that once launched the threat of an atmospheric drag on the spacecraft is properly taken into account. Cosmic ray data seem to indicate that solar activity cycle 22 will surpass SAC 21 in activity. The value of R sub m for SAC 22 may approach that of SAC 19. It would be interesting to see whether this prediction is borne out. Researchers are greatly encouraged to proceed with the development of a comprehensive prediction model which includes information provided by cosmic ray data.

  2. Solar/gas Rankine/Rankine-cycle heat pump assessment

    NASA Astrophysics Data System (ADS)

    Khalifa, H. E.; Melikian, G.

    1982-07-01

    This report contains an assessment of the technical and economic feasibility of Rankine-cycle solar-augmented gas-fired heat pumps (SAGFHP) for multi-family residential and light-commercial applications. The SAGFHP design considered in this report is based on the successful UTRC turbocompressor system which has been tested both in the laboratory and in a solar cooling installation in Phoenix. AZ. An hour-by-hour modeling of present-design SAGFHP performance in multi-family and office buildings in New York, Wisconsin, Nebraska and Oregon indicated that, even without solar augmentation, primary energy savings of up 17% and 31% could be achieved relative to advanced furnace plus electric air conditioning systems and electric heat pumps, respectively.

  3. "Le Droit de L'Enfant:" Ideologies of the Child in 19th Century French Literature and Child Welfare Reform.

    ERIC Educational Resources Information Center

    Kirschner, Suzanne

    This paper examines ideological themes present in movements for child labor reform and in literature in 19th century France. Separate sections cover early industrialization and child labor reform, the image of the romantic child in French literature, and ideology and reforms. By the mid-19th century, England, America, and France all had their…

  4. Drought over Seoul and Its Association with Solar Cycles

    NASA Astrophysics Data System (ADS)

    Park, Jong-Hyeok; Chang, Heon-Young

    2013-12-01

    We have investigated drought periodicities occurred in Seoul to find out any indication of relationship between drought in Korea and solar activities. It is motivated, in view of solar-terrestrial connection, to search for an example of extreme weather condition controlled by solar activity. The periodicity of drought in Seoul has been re-examined using the wavelet transform technique as the consensus is not achieved yet. The reason we have chosen Seoul is because daily precipitation was recorded for longer than 200 years, which meets our requirement that analyses of drought frequency demand long-term historical data to ensure reliable estimates. We have examined three types of time series of the Effective Drought Index (EDI). We have directly analyzed EDI time series in the first place. And we have constructed and analyzed time series of histogram in which the number of days whose EDI is less than -1.5 for a given month of the year is given as a function of time, and one in which the number of occasions where EDI values of three consecutive days are all less than -1.5 is given as a function of time. All the time series data sets we analyzed are periodic. Apart from the annual cycle due to seasonal variations, periodicities shorter than the 11 year sunspot cycle, ~ 3, ~ 4, ~ 6 years, have been confirmed. Periodicities to which theses short periodicities (shorter than Hale period) may be corresponding are not yet known. Longer periodicities possibly related to Gleissberg cycles, ~ 55, ~ 120 years, can be also seen. However, periodicity comparable to the 11 year solar cycle seems absent in both EDI and the constructed data sets.

  5. Design and fabrication of brayton cycle solar heat receiver

    NASA Technical Reports Server (NTRS)

    Mendelson, I.

    1971-01-01

    A detail design and fabrication of a solar heat receiver using lithium fluoride as the heat storage material was completed. A gas flow analysis was performed to achieve uniform flow distribution within overall pressure drop limitations. Structural analyses and allowable design criteria were developed for anticipated environments such as launch, pressure containment, and thermal cycling. A complete heat receiver assembly was fabricated almost entirely from the refractory alloy, niobium-1% zirconium.

  6. Comparing Coronal and Heliospheric Magnetic Fields over Several Solar Cycles

    NASA Astrophysics Data System (ADS)

    Koskela, J. S.; Virtanen, I. I.; Mursula, K.

    2017-01-01

    Here we use the PFSS model and photospheric data from Wilcox Solar Observatory, SOHO/MDI, SDO/HMI, and SOLIS to compare the coronal field with heliospheric magnetic field measured at 1 au, compiled in the NASA/NSSDC OMNI 2 data set. We calculate their mutual polarity match and the power of the radial decay, p, of the radial field using different source surface distances and different number of harmonic multipoles. We find the average polarity match of 82% for the declining phase, 78%–79% for maxima, 76%–78% for the ascending phase, and 74%–76% for minima. On an average, the source surface of 3.25 RS gives the best polarity match. We also find strong evidence for solar cycle variation of the optimal source surface distance, with highest values (3.3 RS) during solar minima and lowest values (2.6 RS–2.7 RS) during the other three solar cycle phases. Raising the number of harmonic terms beyond 2 rarely improves the polarity match, showing that the structure of the HMF at 1 au is most of the time rather simple. All four data sets yield fairly similar polarity matches. Thus, polarity comparison is not affected by photospheric field scaling, unlike comparisons of the field intensity.

  7. Jovian Northern Ethane Aurora and the Solar Cycle

    NASA Technical Reports Server (NTRS)

    Kostiuk,T.; Livengood, T.; Fast, K.; Buhl, D.; Goldstein, J.; Hewagama, T.

    1999-01-01

    Thermal infrared auroral spectra from Jupiter's North polar region have been collected from 1979 to 1998 in a continuing study of long-term variability in the northern thermal IR aurora, using C2H6 emission lines near 12 microns as a probe. Data from Voyager I and 2 IRIS measurements and ground based spectral measurements were analyzed using the same model atmosphere to provide a consistent relative comparison. A retrieved equivalent mole fraction was used to compare the observed integrated emission. Short term (days), medium term (months) and long term (years) variability in the ethane emission was observed. The variability Of C2H6 emission intensities was compared to Jupiter's seasonal cycle and the solar activity cycle. A positive correlation appears to exist, with significantly greater emission and short term variability during solar maxima. Observations on 60 N latitude during increased solar activity in 1979, 1989, and most recently in 1998 show up to 5 times brighter integrated line emission of C2H6 near the north polar "hot spot" (150-210 latitude) than from the north quiescent region. Significantly lower enhancement was observed during periods of lower solar activity in 1982, 1983, 1993, and 1995. Possible sources and mechanisms for the enhancement and variability will be discussed.

  8. Solar cycle-dependent helicity transport by magnetic clouds

    NASA Astrophysics Data System (ADS)

    Lynch, B. J.; Gruesbeck, J. R.; Zurbuchen, T. H.; Antiochos, S. K.

    2005-08-01

    Magnetic clouds observed with the Wind and ACE spacecraft are fit with the static, linear force-free cylinder model to obtain estimates of the chirality, fluxes, and magnetic helicity of each event. The fastest magnetic clouds (MCs) are shown to carry the most flux and helicity. We calculate the net cumulative helicity which measures the difference in right- and left-handed helicity contained in MCs over time. The net cumulative helicity does not average to zero; rather, a strong left-handed helicity bias develops over the solar cycle, dominated by the largest events of cycle 23: Bastille Day 2000 and 28 October 2003. The majority of MCs ("slow" events, < 500 km/s) have a net cumulative helicity profile that appears to be modulated by the solar activity cycle. This is far less evident for "fast" MC events ( ≥ 500 km/s), which were disproportionately left-handed over our data set. A brief discussion about the various solar sources of CME helicity and their implication for dynamo processes is included.

  9. The tympanostomy tube: an ingenious invention of the mid 19th century.

    PubMed

    Mudry, Albert

    2013-02-01

    The introduction of the tympanostomy tube in the treatment of otitis media with effusion in the mid 20th century completely revolutionized its therapy. Nevertheless, it was not a new idea. The aim of this research is to elucidate the origin of prosthetic middle ear ventilation in the mid 19th century. A review of primary sources revealed at least seven different models of tympanostomy tube which were manufactured between 1845 and 1875. These included: Frank's gold tube, Lincke's rubber tube, Bonnafont's silver cannula, Politzer's hard rubber drain, Miot's metallic eyelet, Voltolini's gold ring, and Bonnafont's eyelet. Study of these early innovations shows that all of the technical and surgical principles of the tympanostomy tube were known in the mid 19th century. Widespread introduction into otological practice did not occur until the mid 20th century invention of the operating microscope.

  10. Racial differences in body mass indices of men imprisoned in 19th Century Texas.

    PubMed

    Carson, Scott Alan

    2009-03-01

    A limited amount of research has been done on the body mass index values of 19th century Americans. This paper uses Texas prison records to demonstrate that, in contrast to today's distributions, most BMI values were in the normal range. Only 21.5% and 1.2% of the population was overweight or obese, while today comparable figures are 36% and 23%. There was also little change in BMI values between 1876 and 1919. Farmers were consistently heavier than non-farmers, while Southwestern men had lower BMI values than their counterparts from other regions of the US. BMI values indicate that 19th century African-Americans, and whites populations were well fed in spite of large expenditures on energy.

  11. [Criminology and superstition at the turn of the 19th century].

    PubMed

    Bachhiesl, Christian

    2012-01-01

    Criminology, which institutionalised at university level at the turn of the 19th century, was intensively engaged in the exploration of superstition. Criminologists investigated the various phenomena of superstition and the criminal behaviour resulting from it. They discovered bizarre (real or imagined) worlds of thought and mentalities, which they subjected to a rationalistic regime of interpretation in order to arrive at a better understanding of offences and crimes related to superstition. However, they sometimes also considered the use of occultist practices such as telepathy and clairvoyance to solve criminal cases. As a motive for committing homicide superstition gradually became less relevant in the course of the 19th century. Around 1900, superstition was accepted as a plausible explanation in this context only if a psychopathic form of superstition was involved. In the 20th century, superstition was no longer regarded as an explanans but an explanandum.

  12. Physics education in the Greek community schools of Istanbul (19th century). The books

    NASA Astrophysics Data System (ADS)

    Lazos, Panayotis; Vlahakis, George N.

    2016-03-01

    During the 19th century a number of elementary and high schools were established for the need of the Greek community of Istanbul. Among the courses included in the curricula were those concerning the scientific study of Nature like Botany, Chemistry and Physics. In the present study we attempt to give a thorough description of the educational material used in these schools for the study of natural sciences with an emphasis in Physics. Especially we shall discuss the books used as course books as well as their probable sources. Furthermore we shall try to make a comparison with the relevant situation in the Greek state and the Ottoman Empire, where modern physics had been already introduced through textbooks based on Ganot's treatise on Physics. The results of our research will give for the first time a picture of the way Greek students in the 19th century Istanbul received their basic knowledge about Physics.

  13. Late 19th- and early 20th-century discussions of animal magnetism.

    PubMed

    Alvarado, Carlos S

    2009-10-01

    The mesmerists explained the phenomena of what was later called hypnosis as the effects of a force called animal magnetism. Both psychologists' and physicians' writings generally create the impression that the magnetic movement disappeared after the mid-19th century. While the concept of animal magnetism declined significantly by the end of the 19th century, it did not disappear completely. Some examples include the work of Hector Durville, Henri Durville, Emile Magnin, and Edmund Shaftesbury. Detailed accounts of the work of Edmund Gurney and Albert de Rochas are presented. Similar to its earlier counterpart, the late mesmeric movement was associated with what today is known as parapsychological phenomena. This association, and the belief that the demise of magnetic theory represents scientific progress, has led many to emphasize a history that is incomplete.

  14. ON THE 'EXTENDED' SOLAR CYCLE IN CORONAL EMISSION

    SciTech Connect

    Robbrecht, E.; Wang, Y.-M.; Sheeley, N. R.; Rich, N. B. E-mail: yi.wang@nrl.navy.mi E-mail: nathan.rich@nrl.navy.mi

    2010-06-10

    Butterfly diagrams (latitude-time plots) of coronal emission show a zone of enhanced brightness that appears near the poles just after solar maximum and migrates toward lower latitudes; a bifurcation seems to occur at sunspot minimum, with one branch continuing to migrate equatorward with the sunspots of the new cycle and the other branch heading back to the poles. The resulting patterns have been likened to those seen in torsional oscillations and have been taken as evidence for an extended solar cycle lasting over {approx}17 yr. In order to clarify the nature of the overlapping bands of coronal emission, we construct butterfly diagrams from green-line simulations covering the period 1967-2009 and from 19.5 nm and 30.4 nm observations taken with the Extreme-Ultraviolet Imaging Telescope during 1996-2009. As anticipated from earlier studies, we find that the high-latitude enhancements mark the footpoint areas of closed loops with one end rooted outside the evolving boundaries of the polar coronal holes. The strong underlying fields were built up over the declining phase of the cycle through the poleward transport of active-region flux by the surface meridional flow. Rather than being a precursor of the new-cycle sunspot activity zone, the high-latitude emission forms a physically distinct, U-shaped band that curves upward again as active-region fields emerge at midlatitudes and reconnect with the receding polar-hole boundaries. We conclude that the so-called extended cycle in coronal emission is a manifestation not of early new-cycle activity, but of the poleward concentration of old-cycle trailing-polarity flux by meridional flow.

  15. Space Weather and the Ground-Level Solar Proton Events of the 23rd Solar Cycle

    NASA Astrophysics Data System (ADS)

    Shea, M. A.; Smart, D. F.

    2012-10-01

    Solar proton events can adversely affect space and ground-based systems. Ground-level events are a subset of solar proton events that have a harder spectrum than average solar proton events and are detectable on Earth's surface by cosmic radiation ionization chambers, muon detectors, and neutron monitors. This paper summarizes the space weather effects associated with ground-level solar proton events during the 23rd solar cycle. These effects include communication and navigation systems, spacecraft electronics and operations, space power systems, manned space missions, and commercial aircraft operations. The major effect of ground-level events that affect manned spacecraft operations is increased radiation exposure. The primary effect on commercial aircraft operations is the loss of high frequency communication and, at extreme polar latitudes, an increase in the radiation exposure above that experienced from the background galactic cosmic radiation. Calculations of the maximum potential aircraft polar route exposure for each ground-level event of the 23rd solar cycle are presented. The space weather effects in October and November 2003 are highlighted together with on-going efforts to utilize cosmic ray neutron monitors to predict high energy solar proton events, thus providing an alert so that system operators can possibly make adjustments to vulnerable spacecraft operations and polar aircraft routes.

  16. Proceedings of the 19th annual meeting of the Adhesion Society

    SciTech Connect

    Ward, T.C.

    1996-12-31

    This is the proceedings of the 19th Annual Meeting of the Adhesion Society, held February 18-21, 1996. Papers are presented on various aspects of adhesion, ranging from studies at the molecular level, to studies of the intermixing of polymer chains across interface joints, to the study of polymer/metal joints. Separate abstracts of articles from this proceedings have been indexed into the database.

  17. JPRS Report, Soviet Union, Political Affairs, Preparations for the 19th Party Conference, Part 4.

    DTIC Science & Technology

    2007-11-02

    important element that would be political, that is, would fully meet the require- ments of party allegiance and party policy, which is a science and...historical sciences , former secretary of the party’s Saratov Obkom, under rubric "Towards the 19th Ail-Union Party Conference": "Teaching That Which...only two do not exist, but even one does not exist? According to the data of medical science , the risk factor for getting a heart attack has

  18. [Hygiene, hygienism and public health policy in late 19th century France].

    PubMed

    Cavé, Isabelle

    2015-01-01

    In France the desire to expand public health developed mainly because of the hygienist movement which prevailed in the 19th century. This paper aims to show how medical doctors committed themselves deeply at the Chambre des députés and Sénat with the objective of creating the legislation to control sanitary standards which was written between 1870 and 1914.

  19. Solar cycle variation of the statistical distribution of the solar wind ɛ parameter and its constituent variables

    NASA Astrophysics Data System (ADS)

    Tindale, E.; Chapman, S. C.

    2016-06-01

    We use 20 years of Wind solar wind observations to investigate the solar cycle variation of the solar wind driving of the magnetosphere. For the first time, we use generalized quantile-quantile plots to compare the statistical distribution of four commonly used solar wind coupling parameters, Poynting flux, B2, the ɛ parameter, and vB, between the maxima and minima of solar cycles 23 and 24. We find the distribution is multicomponent and has the same functional form at all solar cycle phases; the change in distribution is captured by a simple transformation of variables for each component. The ɛ parameter is less sensitive than its constituent variables to changes in the distribution of extreme values between successive solar maxima. The quiet minimum of cycle 23 manifests only in lower extreme values, while cycle 24 was less active across the full distribution range.

  20. Characteristics of the 23 Cycle of Solar Activity

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Tamara

    The aim of the present study is to search for special features of the 23-d cycle of solar activity. We present results of our analysis of spectra of sunspot number W for the time intervals of spaced measurements 1964-1997 and 1996-2005 and of the Interplanetary Magnetic Field (IMF), the solar wind velocity (V) calculated on the basis of measurements near the Earth's orbit for the period 1964-1997. A method of non-linear spectral analysis named by us the Method of Global Minimum (MGM) is used. MGM allows self-consistentidentification of trends from data and non-stationary sinusoids and estimation of statistical significance of spectral components. The IMF and W spectra for the period 1964-1997 both show the solar cycle at T=10.8 yr and its higher harmonics. But spectrum of sunspot number W for the period 1996-2005 (time interval of the 23-d cycle) has not spectral component at T=10.8 yr (at confidence statistical level 95%); however, this spectrum has higher harmonics of the 10.8-yr cycle (such as sinusoid with T=146.2 day). The most powerful spectral line from the spectrum (1996-2005) has period T=16.56 yr. We show that tide forces of the planets can be a cause of periodical changes in the analyzed data. Periods of perturbed tide forces of external planets and their higher harmonics (connected with motion of the Sun relative to the mass center of the solar system) are detected in the spectra. In particular, all periods from the spectrum of W for the period 1996-2005 can be interpreted as periods of perturbed tide force of a system: Sun - a pair Jupiter-Uranus: T=16.56 yr is period of perturbed tide force of pair Jupiter-Uranus (1st planet determines shift of mass center of the Sun relative to the mass center of a system the Sunthe 1st planet; the 2nd planet determines perturbed tide force acting on the Sun). The fact that spectrum of W for the period 1996-2005 has the most power spectral components at T=16.56 and T=1.83 yr (9 harmonics of the 16.56-yr cycle

  1. IS SOLAR CYCLE 24 PRODUCING MORE CORONAL MASS EJECTIONS THAN CYCLE 23?

    SciTech Connect

    Wang, Y.-M.; Colaninno, R. E-mail: robin.colaninno@nrl.navy.mil

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  2. Is Solar Cycle 24 Producing More Coronal Mass Ejections Than Cycle 23?

    NASA Astrophysics Data System (ADS)

    Wang, Y.-M.; Colaninno, R.

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  3. [From ancient pot collections to the modern medicines. Menier's pot collection-19th century].

    PubMed

    Demouy, Isabelle

    2012-02-01

    At the beginning of the 19th century in 1816, Jean Antoine Brutus Menier founded the "Maison Centrale de Droguerie Menier". It supplied most of the pharmacies in France with drugs of animal, plant and mineral origin for the pharmaceutical preparations recommended at that time. The company provided training for many chemists and pharmacists, and as such, had a collection of pots containing over seven hundred drugs that is currently held at the head office of the Council of the College of Pharmacists in Paris. After having described the pot collection, set it against the 19th century background which experienced a real revolution within this profession, and after retracing its history, a study was then carried out in order to compare the former uses with the modern uses for each of the drugs. Thanks to this detailed, comparative analysis it is now possible to evaluate the relevance of the therapeutic range of drugs in the first half of the 19th century, before the significant rise in chemistry. The Germinal Law changed the pharmacist's profession, and with the birth of chemistry, the art of the pharmacy was revolutionised. However, the drugs, and particularly those of plant origin, have managed to keep a dominant position in today's pharmaceutical domain and in the French or European Pharmacopoeia.

  4. The psychologist as a poet: Kierkegaard and psychology in 19th-century Copenhagen.

    PubMed

    Pind, Jörgen L

    2016-11-01

    Psychology had an early start at the University of Copenhagen in the first half of the 19th century, where it was taught as the major part of a compulsory course required of all first-year students. Particularly important in the establishment of psychology at the university was Frederik Christian Sibbern, who was professor of philosophy from 1813 to 1870. Sibbern wrote numerous works on psychology throughout his career. In his first book on psychology, Sibbern expressed the view that the ideal psychologist should also be a poet. Søren Kierkegaard, Sibbern's student, was precisely such a poet-psychologist. Kierkegaard discussed psychology in many of his works, reflecting the gathering momentum of psychology in 19th-century Copenhagen, Denmark. The article brings out some aspects of Kierkegaard's poetic and literary-imaginative approach to psychology. In his opinion, psychology was primarily a playful subject and limited in the questions about human nature it could answer, especially when it came up against the "eternal" in man's nature. Kierkegaard had a positive view of psychology, which contrasts sharply with his negative views on the rise of statistics and the natural sciences. In the latter half of the 19th century, psychology turned positivistic at the University of Copenhagen. This left little room for Kierkegaard's kind of poetic psychology. (PsycINFO Database Record

  5. Sun's Polar Magnetic Field Reversals in Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Pishkalo, M. I.; Leiko, U. M.

    It is known that polar magnetic field of the Sun changes its sign at the maximum of solar cycle. These changes were called as polar field reversals. We investigated dynamics of high-latitude solar magnetic fields separately in northern and southern hemispheres. Solar polar field strength measurements from the Wilcox Solar Observatory and low-resolution synoptic magnetic maps from the SOLIS project and from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory were used. We analyzed total magnetic flux at near-polar zones, starting from 55, 60, 65, 70, 75, 80 and 85 degrees of latitude, and found time points when the total magnetic flux changed its sign. It was concluded that total magnetic flux changed its sign at first at lower latitudes and finally near the poles. Single polar magnetic field reversal was found in the southern hemisphere. The northern hemisphere was characterized by three-fold magnetic field reversal. Polar magnetic field reversals finished in northern and southern hemispheres by CR 2150 and CR 2162, respectively.

  6. Recurrence quantification analysis of two solar cycle indices

    NASA Astrophysics Data System (ADS)

    Stangalini, Marco; Ermolli, Ilaria; Consolini, Giuseppe; Giorgi, Fabrizio

    2017-02-01

    Solar activity affects the whole heliosphere and near-Earth space environment. It has been reported in the literature that the mechanism responsible for the solar activity modulation behaves like a low-dimensional chaotic system. Studying these kind of physical systems and, in particular, their temporal evolution requires non-linear analysis methods. To this regard, in this work we apply the recurrence quantification analysis (RQA) to the study of two of the most commonly used solar cycle indicators; i.e. the series of the sunspot number (SSN), and the radio flux 10.7 cm, with the aim of identifying possible dynamical transitions in the system; a task which is particularly suited to the RQA. The outcome of this analysis reveals the presence of large fluctuations of two RQA measures: namely the determinism and the laminarity. In addition, large differences are also seen between the evolution of the RQA measures of the SSN and the radio flux. That suggests the presence of transitions in the dynamics underlying the solar activity. Besides it also shows and quantifies the different nature of these two solar indices. Furthermore, in order to check whether our results are affected by dataartefacts, we have also applied the RQA to both the recently recalibrated SSN series and the previous one, unveiling the main differences between the two data sets. The results are discussed in light of the recent literature on the subject.

  7. Towards better constrained models of the solar magnetic cycle

    NASA Astrophysics Data System (ADS)

    Munoz-Jaramillo, Andres

    2010-12-01

    The best tools we have for understanding the origin of solar magnetic variability are kinematic dynamo models. During the last decade, this type of models has seen a continuous evolution and has become increasingly successful at reproducing solar cycle characteristics. The basic ingredients of these models are: the solar differential rotation -- which acts as the main source of energy for the system by shearing the magnetic field; the meridional circulation -- which plays a crucial role in magnetic field transport; the turbulent diffusivity -- which attempts to capture the effect of convective turbulence on the large scale magnetic field; and the poloidal field source -- which closes the cycle by regenerating the poloidal magnetic field. However, most of these ingredients remain poorly constrained which allows one to obtain solar-like solutions by "tuning" the input parameters, leading to controversy regarding which parameter set is more appropriate. In this thesis we revisit each of those ingredients in an attempt to constrain them better by using observational data and theoretical considerations, reducing the amount of free parameters in the model. For the meridional flow and differential rotation we use helioseismic data to constrain free parameters and find that the differential rotation is well determined, but the available data can only constrain the latitudinal dependence of the meridional flow. For the turbulent magnetic diffusivity we show that combining mixing-length theory estimates with magnetic quenching allows us to obtain viable magnetic cycles and that the commonly used diffusivity profiles can be understood as a spatiotemporal average of this process. For the poloidal source we introduce a more realistic way of modeling active region emergence and decay and find that this resolves existing discrepancies between kinematic dynamo models and surface flux transport simulations. We also study the physical mechanisms behind the unusually long minimum of

  8. Understanding Activity Cycles of Solar Type Stars with Kepler

    NASA Astrophysics Data System (ADS)

    Tovar, Guadalupe; Montet, Benjamin; Johnson, John A.

    2017-01-01

    As the era of exploring new worlds and systems advances we seek to answer the question: How common is our Sun? There is considerable evidence about the recurring activity cycles of our Sun but very little is known about the activity cycles of other stars. By calibrating the full frame images from the original Kepler mission that were taken once a month over the course of four years, we are able to do relative photometry on roughly 5 million stars. By building a model of the pixel response function we were able to achieve 0.8% precision photometry. We identify 50,000 solar type stars based on magnitude, surface gravity, and temperature cuts. We observe the relative increase and decrease in brightness of the stars indicating signs of activity cycles similar to our Sun. We continue to explore how a data driven pixel response function model could improve our precision to 0.1% photometry measurements.

  9. A new simple dynamo model for solar activity cycle

    NASA Astrophysics Data System (ADS)

    Yokoi, Nobumitsu; Schmitt, Dieter

    2015-04-01

    The solar magnetic activity 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 solar activity 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 solar activity 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. Solar Phys. 7, 3 (2010). [2] Yoshizawa, A. Phys. Fluids B 2, 1589 (1990). [3] Yokoi, N. Geophys. Astrophys. Fluid Dyn. 107, 114 (2013).

  10. Solar cycles or random processes? Evaluating solar variability in Holocene climate records.

    PubMed

    Turner, T Edward; Swindles, Graeme T; Charman, Dan J; Langdon, Peter G; Morris, Paul J; Booth, Robert K; Parry, Lauren E; Nichols, Jonathan E

    2016-04-05

    Many studies have reported evidence for solar-forcing of Holocene climate change across a range of archives. These studies have compared proxy-climate data with records of solar variability (e.g. (14)C or (10)Be), or have used time series analysis to test for the presence of solar-type cycles. This has led to some climate sceptics misrepresenting this literature to argue strongly that solar variability drove the rapid global temperature increase of the twentieth century. As proxy records underpin our understanding of the long-term processes governing climate, they need to be evaluated thoroughly. The peatland archive has become a prominent line of evidence for solar forcing of climate. Here we examine high-resolution peatland proxy climate data to determine whether solar signals are present. We find a wide range of significant periodicities similar to those in records of solar variability: periods between 40-100 years, and 120-140 years are particularly common. However, periodicities similar to those in the data are commonly found in random-walk simulations. Our results demonstrate that solar-type signals can be the product of random variations alone, and that a more critical approach is required for their robust interpretation.

  11. Solar cycles or random processes? Evaluating solar variability in Holocene climate records

    PubMed Central

    Turner, T. Edward; Swindles, Graeme T.; Charman, Dan J.; Langdon, Peter G.; Morris, Paul J.; Booth, Robert K.; Parry, Lauren E.; Nichols, Jonathan E.

    2016-01-01

    Many studies have reported evidence for solar-forcing of Holocene climate change across a range of archives. These studies have compared proxy-climate data with records of solar variability (e.g. 14C or 10Be), or have used time series analysis to test for the presence of solar-type cycles. This has led to some climate sceptics misrepresenting this literature to argue strongly that solar variability drove the rapid global temperature increase of the twentieth century. As proxy records underpin our understanding of the long-term processes governing climate, they need to be evaluated thoroughly. The peatland archive has become a prominent line of evidence for solar forcing of climate. Here we examine high-resolution peatland proxy climate data to determine whether solar signals are present. We find a wide range of significant periodicities similar to those in records of solar variability: periods between 40–100 years, and 120–140 years are particularly common. However, periodicities similar to those in the data are commonly found in random-walk simulations. Our results demonstrate that solar-type signals can be the product of random variations alone, and that a more critical approach is required for their robust interpretation. PMID:27045989

  12. Sources of the Slow Solar Wind During the Solar Cycle 23/24 Minimum

    NASA Astrophysics Data System (ADS)

    Kilpua, E. K. J.; Madjarska, M. S.; Karna, N.; Wiegelmann, T.; Farrugia, C.; Yu, W.; Andreeova, K.

    2016-10-01

    We investigate the characteristics and the sources of the slow ({<} 450 km s^{-1}) solar wind during the four years (2006 - 2009) of low solar activity between Solar Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth solar wind ( Wind and ACE) and removed the periods when large-scale interplanetary coronal mass ejections were present. The investigated period features significant variations in the global coronal structure, including the frequent presence of low-latitude active regions in 2006 - 2007, long-lived low- and mid-latitude coronal holes in 2006 - mid-2008 and mostly the quiet Sun in 2009. We examined Carrington rotation averages of selected solar plasma, charge state, and compositional parameters and distributions of these parameters related to the quiet Sun, active region Sun, and the coronal hole Sun. While some of the investigated parameters ( e.g. speed, the C+6/C+4 and He/H ratios) show clear variations over our study period and with solar wind source type, some (Fe/O) exhibit very little changes. Our results highlight the difficulty of distinguishing between the slow solar wind sources based on the inspection of solar wind conditions.

  13. A physical mechanism for the prediction of the sunspot number during solar cycle 21. [graphs (charts)

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Scherrer, P. H.; Svalgaard, L.; Wilcox, J. M.

    1978-01-01

    On physical grounds it is suggested that the sun's polar field strength near a solar minimum is closely related to the following cycle's solar activity. Four methods of estimating the sun's polar magnetic field strength near solar minimum are employed to provide an estimate of cycle 21's yearly mean sunspot number at solar maximum of 140 plus or minus 20. This estimate is considered to be a first order attempt to predict the cycle's activity using one parameter of physical importance.

  14. Solar and Geomagnetic Activity Relation for the Last two Solar Cycles

    NASA Astrophysics Data System (ADS)

    Kilcik, A.; Yiǧit, E.; Yurchyshyn, V.; Ozguc, A.; Rozelot, J. P.

    2017-01-01

    The long-term relationship between solar (sunspot counts in different Zurich sunspot groups, International Sunspot Number (ISSN), solar wind, and X-Ray solar flare index and geomagnetic indices (Ap and Dst) is investigated. Data sets used in this study cover a time period from January 1996 to March 2014. Our main findings are as follows: 1) The best correlation between the sunspot counts and the Ap index are obtained for the large group time series, while the other categories exhibited lower (final and medium) or no correlation at all (small). It is interesting to note that Ap index is delayed by about 13 months relatively to all sunspot count series and ISSN data. 2) The best correlation between the sunspot counts and the Dst index was as well obtained for the large AR time series. The Dst index delays with respect to the large group by about 2 months. 3) The highest correlation between the solar and geomagnetic indices were obtained between the solar wind speed and Ap and Dst indices with zero time delays (r = 0.76, r = 0.52, respectively). 4) The correlation coefficients between the geomagnetic indices (Ap, Dst) and X-Ray solar flare index (r = 0.59, r = -0.48, respectively) are a little higher than the correlation coefficients between these geomagnetic indices and ISSN (r = 0.57, r = -0.43, respectively). 5) The magnitude of all solar and geomagnetic indices (except the solar wind speed) has significantly decreased during the current solar cycle as compared to the same phase of the previous cycle.

  15. Effects of solar cycle 24 activity on WAAS navigation

    NASA Astrophysics Data System (ADS)

    Datta-Barua, Seebany; Walter, Todd; Bust, Gary S.; Wanner, William

    2014-01-01

    This paper reviews the effects of geomagnetic activity of solar 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 solar 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 activity to date in solar cycle 24 has had minor effects on WAAS service coverage, mainly occurring in Alaska and Canada.

  16. Comprehensive Analysis of Coronal Mass Ejection Mass and Energy Properties Over a Full Solar Cycle

    DTIC Science & Technology

    2010-01-01

    the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is the...observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is...1985) and Vourlidas et al. (2002). We discuss several aspects that emerge from the statistical analysis of such a large event sample such as solar

  17. The solar cycle dependence of the location and shape of the Venus bow shock

    NASA Technical Reports Server (NTRS)

    Zhang, T.-L.; Luhmann, J. G.; Russell, C. T.

    1990-01-01

    The Venus terminator bow shock position is monitored and it is shown that the shock radius increases as the solar cycle approaches a new maximum. It is also shown that the subsolar bow shock changes with the solar cycle, and that these positions are correlated with each other and with solar activity. It is hypothesized that, at solar minimum, the magnetic barrier is weak, and that some absorption of solar wind is to be expected.

  18. Observations of hysteresis in solar cycle variations among seven solar activity indicators

    NASA Technical Reports Server (NTRS)

    Bachmann, Kurt T.; White, Oran R.

    1994-01-01

    We show that smoothed time series of 7 indices of solar activity exhibit significant solar 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 solar cycle, giving evidence that this is a normal feature of solar 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 activity indices during the emergence and decay of major active regions. We argue that hysteresis represents a real delay in the onset and decline of solar activity and is an important clue in the search for physical processes responsible for changing solar emission at various wavelengths.

  19. Galactic and solar radiation exposure to aircrew during a solar cycle.

    PubMed

    Lewis, B J; Bennett, L G I; Green, A R; McCall, M J; Ellaschuk, B; Butler, A; Pierre, M

    2002-01-01

    An on-going investigation using a tissue-equivalent proportional counter (TEPC) has been carried out to measure the ambient dose equivalent rate of the cosmic radiation exposure of aircrew during a solar cycle. A semi-empirical model has been derived from these data to allow for the interpolation of the dose rate for any global position. The model has been extended to an altitude of up to 32 km with further measurements made on board aircraft and several balloon flights. The effects of changing solar modulation during the solar cycle are characterised by correlating the dose rate data to different solar potential models. Through integration of the dose-rate function over a great circle flight path or between given waypoints, a Predictive Code for Aircrew Radiation Exposure (PCAIRE) has been further developed for estimation of the route dose from galactic cosmic radiation exposure. This estimate is provided in units of ambient dose equivalent as well as effective dose, based on E/H x (10) scaling functions as determined from transport code calculations with LUIN and FLUKA. This experimentally based treatment has also been compared with the CARI-6 and EPCARD codes that are derived solely from theoretical transport calculations. Using TEPC measurements taken aboard the International Space Station, ground based neutron monitoring, GOES satellite data and transport code analysis, an empirical model has been further proposed for estimation of aircrew exposure during solar particle events. This model has been compared to results obtained during recent solar flare events.

  20. Climate Sensitivity and Solar Cycle Response in Climate Models

    NASA Astrophysics Data System (ADS)

    Liang, M.; Lin, L.; Tung, K. K.; Yung, Y. L.

    2011-12-01

    Climate sensitivity, broadly defined, is a measure of the response of the climate system to the changes of external forcings such as anthropogenic greenhouse emissions and solar radiation, including climate feedback processes. General circulation models provide a means to quantitatively incorporate various feedback processes, such as water-vapor, cloud and albedo feedbacks. Less attention is devoted so far to the role of the oceans in significantly affecting these processes and hence the modelled transient climate sensitivity. Here we show that the oceanic mixing plays an important role in modifying the multi-decadal to centennial oscillations of the sea surface temperature, which in turn affect the derived climate sensitivity at various phases of the oscillations. The eleven-year solar cycle forcing is used to calibrate the response of the climate system. The GISS-EH coupled atmosphere-ocean model was run twice in coupled mode for more than 2000 model years, each with a different value for the ocean eddy mixing parameter. In both runs, there is a prominent low-frequency oscillation with a period of 300-500 years, and depending on the phase of such an oscillation, the derived climate gain factor varies by a factor of 2. The run with the value of the eddy ocean mixing parameter that is half that used in IPCC AR4 study has the more realistic low-frequency variability in SST and in the derived response to the known solar-cycle forcing.

  1. Solar and interplanetary particles at 2 to 4 MEV during solar cycles 21, solar cycle variations of event sizes, and compositions

    NASA Technical Reports Server (NTRS)

    Armstrong, T. P.; Shields, J. C.; Briggs, P. R.; Eckes, S.

    1985-01-01

    In This paper 2 to 4 MeV/nucleon protons, alpha particles, and medium (CNO) nuclei in the near-Earth interplanetary medium during the years 1974 to 1981 are studied. This period contains both the solar activity minimum in 1976, and the very active onset phase of Solar Cycle 21. Characteristic compositional differences between the solar minimum and solar maximum ion populations have been investigated. Previous studies of interplanetary composition at these energies have concentrated on well-defined samples of the heliospheric medium. During flare particle events, the ambient plasma is dominated by ions accelerated in specific regions of the solar atmosphere; observation of the proton/alpha and alpha/medium ratios for flare events shows that there is marked compositional variability both during an event and from event to event suggesting the complicated nature of flare particle production and transport.

  2. Solar Thermochemical Fuels Production: Solar Fuels via Partial Redox Cycles with Heat Recovery

    SciTech Connect

    2011-12-19

    HEATS Project: The University of Minnesota is developing a solar thermochemical reactor that will efficiently produce fuel from sunlight, using solar energy to produce heat to break chemical bonds. The University of Minnesota is envisioning producing the fuel by using partial redox cycles and ceria-based reactive materials. The team will achieve unprecedented solar-to-fuel conversion efficiencies of more than 10% (where current state-of-the-art efficiency is 1%) by combined efforts and innovations in material development, and reactor design with effective heat recovery mechanisms and demonstration. This new technology will allow for the effective use of vast domestic solar resources to produce precursors to synthetic fuels that could replace gasoline.

  3. An Educational Display of the Solar Magnetic Cycle: Year 2

    NASA Astrophysics Data System (ADS)

    Jones, H. P.; Gearen, M. V.; Jacoby, S. H.

    1999-05-01

    We are developing an educational module to improve student and public understanding of the Sun's magnetic cycle. The instructional package features a CDROM compatible with most personal computers available in the home or classroom with a day-by-day record of an entire magnetic cycle as recorded in magnetograms from the National Solar Observatory Kitt Peak Vacuum Telescope (NSO/KPVT) near Tucson, AZ. These data have in fact been crucial to developing our present understanding of the solar cycle and its terrestrial effects. In the second year of the project, we have loaded the data to compact disks both as individual "gif" files for inspection and analysis and as QuickTime movies, have prepared the first version of the accompanying textual material, and are developing macros to aid extraction of information from the data for various laboratory exercises. We will display samples of these images and movies, and will furnish copies of the compact disks and accompanying textual material for testing and comment.

  4. Solar cycle effect on atmospheric carbon dioxide levels. Final report

    SciTech Connect

    Kirk, B.L.; Rust, B.W.

    1983-01-01

    The authors present a causal time-series model for the Mauna Loa atmospheric CO2 record which supersedes a mathematical model consisting of four effects represented by exponential and sine functions. One effect is a 142-month oscillation which trails the sunspot numbers by exactly a quarter-cycle. This suggests that solar activity affects the rate of change in the atmospheric CO2 abundance. The new model replaces the mathematical functions with four measured time series representing proposed physical causes and reduces the number of adjustable parameters from 13 to 5 with no significant deterioration in the fit. The authors present evidence that solar activity affects the CO2 abundance through variations in ocean temperature or circulation.

  5. Solar Cycle Variations of Fe-rich SEP Events

    NASA Astrophysics Data System (ADS)

    Cane, H. V.; Richardson, I. G.

    2006-12-01

    An investigation of the characteristics of large solar energetic particle (SEP) events with >25 MeV/nuc event- -averaged Fe/O above 0.5 shows that such events have a rapid rise to maximum intensity and little evidence of particle acceleration at the passage of an interplanetary shock in this energy range. We explore the reasons why such events were not seen by near--Earth spacecraft in 2004 and 2005. One reason, that we have already documented, is that fast shocks (transit speeds above 1000 km/s) are relatively more common after solar maximum. The disappearance of Fe--rich events late in Cycle 23 has been used by Tylka et al. (2006) to argue for the absence of flare particles both as seed particles for shocks and as direct contributors to large SEP events. However, such arguments ignore the fact that there were no events with the other characteristics of Fe-rich events.

  6. Detection of the climate response to the solar cycle

    SciTech Connect

    Stevens, M.J.; North, G.R.

    1996-09-15

    Optimal space-time signal processing is used to infer the amplitude of the large-scale, near-surface temperature response to the {open_quotes}11 year{close_quotes} solar cycle. The estimation procedure involves the following steps. (1) By correlating 14 years of monthly total solar irradiance measurements made by the Nimbus-7 satellite and monthly Wolf sunspot numbers, a monthly solar irradiance forcing function is constructed for the years 1894-1993. (2) Using this forcing function, a space-time waveform of the climate response for the same 100 years is generated from an energy balance climate model. (3) The space-time covariance statistics in the frequency band (16.67 yr){sup {minus}1}-(7.14 yr){sup {minus}1} are calculated using control runs from two different coupled ocean-atmosphere global climate models. (4) Using the results from the last two steps, an optimal filter is constructed and applied to observed surface temperature data for the years 1894-1993. (5) An estimate of the ratio of the real climate response, contained in the observed data, and the model generated climate response from step 2 is given, as well as an estimate of its uncertainty. A number of consistency checks are presented, such as using data from different regions of the earth to calculate this ratio and using data lagged up to {+-}5 yr. The authors findings allow them to reject the null hypothesis, that no response to the solar cycle is present in the data, at a confidence level of 97.4%. 44 refs., 15 figs., 3 tabs.

  7. Solar photospheric network properties and their cycle variation

    SciTech Connect

    Thibault, K.; Charbonneau, P.; Béland, M. E-mail: paulchar@astro.umontreal.ca-b

    2014-11-20

    We present a numerical simulation of the formation and evolution of the solar photospheric magnetic network over a full solar cycle. The model exhibits realistic behavior as it produces large, unipolar concentrations of flux in the polar caps, a power-law flux distribution with index –1.69, a flux replacement timescale of 19.3 hr, and supergranule diameters of 20 Mm. The polar behavior is especially telling of model accuracy, as it results from lower-latitude activity, and accumulates the residues of any potential modeling inaccuracy and oversimplification. In this case, the main oversimplification is the absence of a polar sink for the flux, causing an amount of polar cap unsigned flux larger than expected by almost one order of magnitude. Nonetheless, our simulated polar caps carry the proper signed flux and dipole moment, and also show a spatial distribution of flux in good qualitative agreement with recent high-latitude magnetographic observations by Hinode. After the last cycle emergence, the simulation is extended until the network has recovered its quiet Sun initial condition. This permits an estimate of the network relaxation time toward the baseline state characterizing extended periods of suppressed activity, such as the Maunder Grand Minimum. Our simulation results indicate a network relaxation time of 2.9 yr, setting 2011 October as the soonest the time after which the last solar activity minimum could have qualified as a Maunder-type Minimum. This suggests that photospheric magnetism did not reach its baseline state during the recent extended minimum between cycles 23 and 24.

  8. Solar Sources and Geospace Consequences of Interplanetary Magnetic Clouds Observed During Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.

    2007-01-01

    We present results of a statistical investigation of 99 magnetic clouds (MCs) observed during 1995-2005. The MC-associated coronal mass ejections (CMEs) are faster and wider on the average and originate within +/-30deg from the solar disk center. The solar sources of MCs also followed the butterfly diagram. The correlation between the magnetic field strength and speed of MCs was found to be valid over a much wider range of speeds. The number of south-north (SN) MCs was dominant and decreased with solar cycle, while the number of north-south (NS) MCs increased confirming the odd-cycle behavior. Two-thirds of MCs were geoeffective; the Dst index was highly correlated with speed and magnetic field in MCs as well as their product. Many (55%) fully northward (FN) MCs were geoeffective solely due to their sheaths. The non-geoeffective MCs were slower (average speed approx. 382 km/s), had a weaker southward magnetic field (average approx. -5.2nT), and occurred mostly during the rise phase of the solar activity cycle.

  9. [Epidemic Cholera and American Reform Movements in the 19th Century].

    PubMed

    Kim, Seohyung

    2015-12-01

    The 19th century was the age of great reform in American history. After constructing of the canal and railroads, the industrialization began and American society changed so rapidly. In this period, there were so many social crisis and American people tried to solve these problems within the several reform movements. These reform movements were the driving forces to control cholera during the 19th century. Cholera was the endemic disease in Bengal, India, but after the 19th century it had spread globally by the development of trade networks. The 1832 cholera in the United States was the first epidemic cholera in American history. The mortality of cholera was so high, but it was very hard to find out the cause of this fatal infectious disease. So, different social discourses happened to control epidemic cholera in the 19th century, these can be understood within the similar context of American reform movements during this period. Board of Health in New York States made a new public health act to control cholera in 1832, it was ineffective. Some people insisted that the cause of this infectious disease was the corruption of the United States. They emphasized unjust and immoral system in American society. Moral reform expanded to Nativism, because lots of Irish immigrants were the victims of cholera. So, epidemic cholera was the opportunity to spread the desire for moral reform. To control cholera in 1849, the sanitary reform in Britain had affected. The fact that it was so important to improve and maintain the water quality for the control and prevention of disease spread, the sanitary reform happened. There were two different sphere of the sanitary reform. The former was the private reform to improve sewer or privy, the latter was the public reform to build sewage facilities. The 1849 cholera had an important meaning, because the social discourse, which had emphasized the sanitation of people or home expanded to the public sphere. When cholera broke out in 1866 again

  10. Intermittency of the Solar Magnetic Field and Solar Magnetic Activity Cycle

    NASA Astrophysics Data System (ADS)

    Shibalova, A. S.; Obridko, V. N.; Sokoloff, D. D.

    2017-03-01

    Small-scale solar magnetic fields demonstrate features of fractal intermittent behavior, which requires quantification. For this purpose we investigate how the observational estimate of the solar magnetic flux density B depends on resolution D in order to obtain the scaling ln BD = - k ln D +a in a reasonably wide range. The quantity k demonstrates cyclic variations typical of a solar activity cycle. In addition, k depends on the magnetic flux density, i.e. the ratio of the magnetic flux to the area over which the flux is calculated, at a given instant. The quantity a demonstrates some cyclic variation, but it is much weaker than in the case of k. The scaling obtained generalizes previous scalings found for the particular cycle phases. The scaling is typical of fractal structures. In our opinion, the results obtained trace small-scale action in the solar convective zone and its coexistence with the conventional large-scale solar dynamo based on differential rotation and mirror-asymmetric convection.

  11. On the reduced geoeffectiveness of solar cycle 24: A moderate storm perspective

    NASA Astrophysics Data System (ADS)

    Selvakumaran, R.; Veenadhari, B.; Akiyama, S.; Pandya, Megha; Gopalswamy, N.; Yashiro, S.; Kumar, Sandeep; Mäkelä, P.; Xie, H.

    2016-09-01

    The moderate and intense geomagnetic storms are identified for the first 77 months of solar cycles 23 and 24. The solar sources responsible for the moderate geomagnetic storms are indentified during the same epoch for both the cycles. Solar cycle 24 has shown nearly 80% reduction in the occurrence of intense storms whereas it is only 40% in case of moderate storms when compared to previous cycle. The solar and interplanetary characteristics of the moderate storms driven by coronal mass ejection (CME) are compared for solar cycles 23 and 24 in order to see reduction in geoeffectiveness has anything to do with the occurrence of moderate storm. Though there is reduction in the occurrence of moderate storms, the Dst distribution does not show much difference. Similarly, the solar source parameters like CME speed, mass, and width did not show any significant variation in the average values as well as the distribution. The correlation between VBz and Dst is determined, and it is found to be moderate with value of 0.68 for cycle 23 and 0.61 for cycle 24. The magnetospheric energy flux parameter epsilon (ɛ) is estimated during the main phase of all moderate storms during solar cycles 23 and 24. The energy transfer decreased in solar cycle 24 when compared to cycle 23. These results are significantly different when all geomagnetic storms are taken into consideration for both the solar cycles.

  12. Glacier changes on South Georgia since the late-19th century documented in historical photographs

    NASA Astrophysics Data System (ADS)

    Gordon, John; Haynes, Valerie

    2014-05-01

    South Georgia is one of the few landmasses in the Southern Ocean. It provides a crucial geographical datapoint for glacier responses to climate change over different timescales. As part of an ongoing glacier inventory of the island, we are compiling a database of historical glacier photographs. Since the late 19th century, the island has been visited by numerous scientific and survey expeditions, as well as being the land-base for a major whaling industry. Historical photographs of the island are available from the late-19th century, beginning with the 1882-83 German International Polar Year Expedition. Many more exist from the 20th century, notably from the South Georgia Surveys in the 1950s. An assessment of the value of the photographs indicates that spatial coverage is variable, many lack reference features to pinpoint glacier positions and, in the case of smaller glaciers, the presence of snowcover makes it difficult to define the ice edge. Nevertheless, the photographs provide useful corroboration of more advanced glacier positions during the late-19th century and recession of smaller mountain and valley glaciers during the mid-20th century, while larger tidewater and sea-calving glaciers generally remained in relatively advanced positions until the 1980s. Since then, nearly all the glaciers have retreated; some of these retreats have been dramatic and a number of small mountain glaciers have fragmented or disappeared. The response of the glaciers can be related to synoptic-scale warming, particularly since the 1950s, moderated by individual glacier geometry and topography.

  13. The solar corona through the sunspot cycle: preparing for the August 21, 2017, total solar eclipse

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.; Seaton, Daniel; Rusin, Vojtech

    2017-01-01

    We discuss the evolution of the solar corona as seen at eclipses through the solar-activity cycle. In particular, we discuss the variations of the overall shape of the corona through the relative proportions of coronal streamers at equatorial and other latitudes vs. polar plumes. We analyze the two coronal mass ejections that we observed from Gabon at the 2013 total solar eclipse and how they apparently arose from polar crown filaments, one at each pole. We describe the change in the Ludendorff flattening index from solar maximum in one hemisphere as of the 2013 eclipse through the 2015 totality's corona we observed from Svalbard and, with diminishing sunspot and other magnetic activity in each hemisphere, through the 2016 corona we observed from Ternate, Indonesia.We discuss our observational plans for the August 21, 2017, total solar eclipse from our main site in Salem, Oregon, and subsidiary sites in Madras, OR; Carbondale, IL; and elsewhere, our main site chosen largely by its favorable rating in cloudiness statistics. We discuss the overlapping role of simultaneous spacecraft observations, including those expected not only from NASA's SDO, ESA's SWAP on PROBA2, and NRL/NASA/ESA's LASCO on SOHO but also from the new SUVI (Solar Ultraviolet Imager) aboard NOAA's GOES-R satellite, scheduled as of this writing to have been launched by the time of this January 2017 meeting.Our research on the 2013 and 2015 total solar eclipses was supported by grants from the Committee for Research and Exploration of the National Geographic Society (NG-CRE). Our research on the 2017 total solar eclipse is supported by both NG-CRE and the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation.

  14. Parents and children: ideas of heredity in the 19th century.

    PubMed

    Waller, John C

    2003-06-01

    The concept of heredity played a powerful role in structuring 19th-century debates over sickness, morality, class, race, education, social change and evolution. But there was very little agreement as to which qualities were heritable and how new hereditary variants were acquired. In consequence, notions of heredity existed in a wide variety of forms, expressing anything from extreme determinism and a belief in the incorrigibility of individuals, social and racial groups, to unleavened optimism, and a faith in ultimate human perfectibility. This article explores these rich hereditarian discourses to convey an impression of a century that was at least as preoccupied with the concept of biological inheritance as we are today.

  15. A 19th Century "Ideal" Oil Paint Medium: A Complex Hybrid Organic-Inorganic Gel.

    PubMed

    de Viguerie, Laurence; Jaber, Maguy; Pasco, Hélène; Lalevée, Jacques; Morlet-Savary, Fabrice; Ducouret, Guylaine; Rigaud, Baptiste; Pouget, Thierry; Sanchez, Clément; Walter, Philippe

    2017-02-01

    British 19th century painters such as J. M. W. Turner, commonly modified the properties of their paint by using gels called "gumtions". These gels allowed them to easily tune the paint handling and drying properties. The fascinating properties of these "gumtions" were obtained by adding lead acetate to a ternary system based on mastic resin, linseed oil and turpentine. Herein, we report and investigate in depth the rheological properties of these gels as well as their structure at a molecular and supra-molecular scale.

  16. [Private clinics in Nuremberg in the 19th and 20th century].

    PubMed

    Vasold, Manfred

    2008-01-01

    As a consequence of the industrialization German cities grew very rapidly during the 19th century. Nuremberg reached the number of 100 000 in 1881. Although that city had a large Municipality Hospital (since 1845), a number of specialized private hospitals was founded. Julius Cnopf, a doctor from Nuremberg, founded a children's hospital, one of the first children's hospitals in Germany. The Nuremberg Muncipality Hospital had more than 1000 beds before 1914 and many more than 2000 after 1945, for this reason the number of private owned hospitals remained rather small. Nonetheless were these small and highly specialized hospitals quite important for the city population of Nuremberg.

  17. An archival exploration of 19th-century American adult female offender parricides.

    PubMed

    Shon, Phillip Chong Ho; Williams, Christopher R

    2013-01-01

    Social and behavioral scientists have increasingly attended to the contexts and motivational dynamics underlying parricidal events. These efforts notwithstanding, most research has focused on adolescent or adult male offender populations. One largely neglected area of study is that of adult female offender parricide. The present study utilizes archival records to examine the contexts and sources of conflict that gave rise to adult female offender parricides in the late 19th century. Three general themes emerged, representing the primary contexts behind adult female offender parricide: (1) abuse and neglect; (2) instrumental, financially-motivated killings; and (3) expressive killings, often during the course of arguments. Each of these contexts is explored.

  18. [Emergence, migrations and reduction to routine in the political sciences (17th-19th centuries)].

    PubMed

    Beaud, Jean-Pierre

    2009-01-01

    This article explores the paths through which percentage imposed itself in the political sciences. At first used in the financial domain, percentage is incorporated in 1662 by Graunt in the field of studies of mortality; in the beginning of the 19th century it migrates towards studies in population growth, then it migrates to other territories to become a tool of general application. Each migration enters the framework of a new problematic: "the birth of mortality" in one case; "the birth of population" in the other. The recourse to percentages thus appears as one of the elements in the foundation of statistical objectivism.

  19. [The politics of the self: psychological science and bourgeois subjectivity in 19th century Spain.].

    PubMed

    Novella, Enric J

    2010-01-01

    This paper offers an analysis of the process of institutionalization of psychological knowledge in Spain following the educative reforms implemented during the second third of the 19th century, which prescribed its inclusion in the curricular program of the new secondary education. After a detailed examination of the theoretical orientation, the ideological assumptions and the socio-political connections of the contents transmitted to the students throughout the century, its militant spiritualism is interpreted as a highly significant attempt on the part of the liberal elites to articulate a pedagogy of subjectivity intended to counteract the trends toward reduction, naturalization and fragmentation of psychic life inherent to the development of modern science.

  20. [The explicative models of infectious diseases in Canada in the 19th Century].

    PubMed

    Goulet, Denis; Thouez, Jean-Pierre

    2004-01-01

    Until the last third of the 19th Century in Canada, physicians looked for the causes of infectious diseases and adopted explicative models associated to airist theories, climatic variations and the physical environment. Rarely did they mention the social environment. Yet, the interpretation of disease plays a fundamental role in the elaboration of preventive measures. Consequently, Canadian physicians adopted a naturalist approach based on local sanitation rather than a social approach of the disease. This reinforced the concept of "predisposing causes". By examining local conditions and, to a lesser extent, the living conditions of Quebec's population, the pre-bacteriologist theories prepared the way for the intervention of modern hygienists.

  1. Structure and sources of solar wind in the growing phase of 24th solar cycle

    NASA Astrophysics Data System (ADS)

    Slemzin, Vladimir; Goryaev, Farid; Shugay, Julia; Rodkin, Denis; Veselovsky, Igor

    2015-04-01

    We present analysis of the solar wind (SW) structure and its association with coronal sources during the minimum and rising phase of 24th solar cycle (2009-2011). The coronal sources prominent in this period - coronal holes, small areas of open magnetic fields near active regions and transient sources associated with small-scale solar activity have been investigated using EUV solar images and soft X-ray fluxes obtained by the CORONAS-Photon/TESIS/Sphinx, PROBA2/SWAP, Hinode/EIS and AIA/SDO instruments as well as the magnetograms obtained by HMI/SDO. It was found that at solar minimum (2009) velocity and magnetic field strength of high speed wind (HSW) and transient SW from small-scale flares did not differ significantly from those of the background slow speed wind (SSW). The major difference between parameters of different SW components was seen in the ion composition represented by the C6/C5, O7/O6, Fe/O ratios and the mean charge of Fe ions. With growing solar activity, the speed of HSW increased due to transformation of its sources - small-size low-latitude coronal holes into equatorial extensions of large polar holes. At that period, the ion composition of transient SW changed from low-temperature to high-temperature values, which was caused by variation of the source conditions and change of the recombination/ionization rates during passage of the plasma flow through the low corona. However, we conclude that criteria of separation of the SW components based on the ion ratios established earlier by Zhao&Fisk (2009) for higher solar activity are not applicable to the extremely weak beginning of 24th cycle. The research leading to these results has received funding from the European Commission's Seventh Framework Programme (FP7/2007-2013) under the grant agreement eHeroes (project n° 284461, www.eheroes.eu).

  2. The long-period of the real moon-solar cycle

    NASA Astrophysics Data System (ADS)

    Mikhalchuk, V. V.

    2014-10-01

    The long-period moon-solar cycle consisting of an integer of 19-years cycles are established. The secular correction is obtained, permitting to increase the exactitude of a calculation of age of Moon, and the universal formula for a calculation of lunar number in various aspects of moon-solar cycles.

  3. High-Energy Solar Particle Events in Cycle 24

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Makela, P.; Yashiro, S.; Xie, H.; Akiyama, S.; Thakur, N.

    2015-01-01

    The Sun is already in the declining phase of cycle 24, but the paucity of high-energy solar energetic particle (SEP) events continues with only two ground level enhancement (GLE) events as of March 31, 2015. In an attempt to understand this, we considered all the large SEP events of cycle 24 that occurred until the end of 2014. We compared the properties of the associated CMEs with those in cycle 23. We found that the CME speeds in the sky plane were similar, but almost all those cycle-24 CMEs were halos. A significant fraction of (16%) of the frontside SEP events were associated with eruptive prominence events. CMEs associated with filament eruption events accelerate slowly and attain peak speeds beyond the typical GLE release heights. When we considered only western hemispheric events that had good connectivity to the CME nose, there were only 8 events that could be considered as GLE candidates. One turned out to be the first GLE event of cycle 24 (2012 May 17). In two events, the CMEs were very fast (>2000 km/s) but they were launched into a tenuous medium (high Alfven speed). In the remaining five events, the speeds were well below the typical GLE CME speed (2000 km/s). Furthermore, the CMEs attained their peak speeds beyond the typical heights where GLE particles are released. We conclude that several factors contribute to the low rate of high-energy SEP events in cycle 24: (i) reduced efficiency of shock acceleration (weak heliospheric magnetic field), (ii) poor latitudinal and longitudinal connectivity), and (iii) variation in local ambient conditions (e.g., high Alfven speed).

  4. Yale University Is Preserving Its Great Late-19th-Century Architecture by Remodeling the Old Campus

    ERIC Educational Resources Information Center

    Architectural Record, 1977

    1977-01-01

    Renovation of four late-19th-century Yale dormitories makes the most of their unique architectural character. Available from: Publications Office, 1221 Avenue of the Americas, New York, New York 10020; $5.00 single copy. (Author/MLF)

  5. Ionospheric response to great geomagnetic storms during solar cycle 23

    NASA Astrophysics Data System (ADS)

    Merline Matamba, Tshimangadzo; Bosco Habarulema, John

    2016-07-01

    The analyses of ionospheric responses due to great geomagnetic storms i.e. Dst index < 350 nT that occurred during solar cycle 23 are presented. The GPS Total Electron Content (TEC) and ionosonde data over Southern and Northern Hemisphere mid-latitudes were used to study the ionospheric responses. A geomagnetic latitude region of ±30° to ±46° within a longitude sector of 15° to 40° was considered. Using a criteria of Dst < -350 nT, there were only four great storm periods (29 March - 02 April 2001, 27 - 31 October 2003, 18 - 23 November 2003 and 06 - 11 November 2004) in solar cycle 23. Analysis has shown that ionospheric dynamics during these disturbed conditions could be due to a number of dynamic and electrodynamics processes in both Hemispheres. In some instances the ionosphere responds differently to the same storm condition in both Hemispheres. Physical mechanisms related to (but not limited to) composition changes and electric fields will be discussed.

  6. Solar energy demand (SED) of commodity life cycles.

    PubMed

    Rugani, Benedetto; Huijbregts, Mark A J; Mutel, Christopher; Bastianoni, Simone; Hellweg, Stefanie

    2011-06-15

    The solar energy demand (SED) of the extraction of 232 atmospheric, biotic, fossil, land, metal, mineral, nuclear, and water resources was quantified and compared with other energy- and exergy-based indicators. SED represents the direct and indirect solar energy required by a product or service during its life cycle. SED scores were calculated for 3865 processes, as implemented in the Ecoinvent database, version 2.1. The results showed that nonrenewable resources, and in particular minerals, formed the dominant contribution to SED. This large share is due to the indirect solar energy required to produce these resource inputs. Compared with other energy- and exergy-based indicators, SED assigns higher impact factors to minerals and metals and smaller impact factors to fossil energetic resources, land use, and nuclear energy. The highest differences were observed for biobased and renewable energy generation processes, whose relative contribution of renewable resources such as water, biomass, and land occupation was much lower in SED than in energy- and exergy-based indicators.

  7. SOLAR CYCLE VARIATION OF SOUND SPEED INSIDE THE SUN

    SciTech Connect

    Mullan, D. J.; MacDonald, J.; Rabello-Soares, M. C.

    2012-08-10

    Empirical radial profiles of the changes in sound speed inside the Sun between solar minimum and solar maximum have been extracted from Michelson Doppler Imager data by Baldner and Basu and Rabello-Soares. Here, we compare these results with the theoretical radial profiles predicted by a model of magnetic inhibition of convective onset: In the model, the degree of magnetic inhibition is characterized by a parameter {delta}, which is essentially the ratio of magnetic pressure to gas pressure. We find that the theoretical profiles overlap significantly with the empirical results in the outer half of the convection zone. But differences in the deeper layers indicate that the model needs to be modified there. The main result that emerges in the present comparison is that the value of {delta} must be larger near the surface than at great depth. A secondary result is that, in the course of the solar cycle, the magnetic field magnitude at the base of the convection zone may be out of phase with the field near the surface.

  8. Hysteresis of indices of solar and ionospheric activity during 11-year cycles

    NASA Astrophysics Data System (ADS)

    Bruevich, E. A.; Kazachevskaya, T. V.; Katyushina, V. V.; Nusinov, A. A.; Yakunina, G. V.

    2016-12-01

    The effects of hysteresis, which is a manifestation of ambiguous relationships between different solar activity indices during the rising and declining phases of solar cycles, are analyzed. The paper addresses the indices characterizing radiation from the solar photosphere, chromosphere, and corona, and the ionospheric indices. The 21st, 22nd, and 23rd solar cycles, which significantly differ from each other in amplitude, exhibit different extents of hysteresis.

  9. Solar Wind Plasma Flows and Space Weather Aspects Recent Solar Cycle

    NASA Astrophysics Data System (ADS)

    Kaushik, Sonia; Kaushik, Subhash Chandra

    2016-07-01

    Solar transients are responsible for initiating short - term and long - term variations in earth's magnetosphere. These variations are termed as geomagnetic disturbances, and driven by the interaction of solar wind features with the geo-magnetosphere. The strength of this modulation process depends upon the magnitude and orientation of the Interplanetary Magnetic Field and solar wind parameters. These interplanetary transients are large scale structures containing plasma and magnetic field expelled from the transient active regions of solar atmosphere. As they come to interplanetary medium the interplanetary magnetic field drape around them. This field line draping was thought as possible cause of the characteristic eastward deflection and giving rise to geomagnetic activities as well as a prime factor in producing the modulation effects in the near Earth environment. The Solar cycle 23 has exhibited the unique extended minima and peculiar effects in the geomagnetosphere. Selecting such transients, occurred during this interval, an attempt has been made to determine quantitative relationships of these transients with solar/ interplanetary and Geophysical Parameters. In this work we used hourly values of IMF data obtained from the NSSD Center. The analysis mainly based on looking into the effects of these transients on earth's magnetic field. The high-resolution data IMF Bz and solar wind data obtained from WDC-A, through its omniweb, available during the selected period. Dst and Ap obtained from WDC-Kyoto are taken as indicator of geomagnetic activities. It is found that Dst index, solar wind velocity, proton temperature and the Bz component of magnetic field have higher values and increase just before the occurrence of these events. Larger and varying magnetic field mainly responsible for producing the short-term changes in geomagnetic intensity are observed during these events associated with coronal holes.

  10. The 'Ajuda Paralyses': history of a neuropsychiatric debate in mid-19th-century Portugal.

    PubMed

    Fontoura, Paulo

    2010-10-01

    The second half of the 19th century witnessed an increasing interest in neurology and psychiatry by Portuguese physicians, in parallel with the overall development of these disciplines in other countries. This process is reflected in the numerous case report publications as well as in debates taking place at the Lisbon Society of Medical Sciences, the major scientific forum of that time. The 'Ajuda Paralyses' were a mysterious succession of epidemics that occurred during 1860-64 in the Ajuda asylum for cholera and yellow fever orphans, which were extensively discussed during 1865-66 by Bernardino Antonio Gomes, Antonio Maria Barbosa, Abel Jordão and Eduardo Motta. Studying this debate helps understand the initial stages of development and the great interest that 'nervous diseases' had for Portuguese clinicians in the mid-19th century and possibly provides one of the first modern descriptions of nutrition-related polyradiculoneuropathy and the ocular findings associated with avitaminosis A. This debate took place at a decisive time for the scientific development of neurology and psychiatry, concurrent with the widespread application of the clinical-anatomical method and neuropathology to the study of diseases of the nervous system, which would set the foundations for our own modern pathophysiological framework. Therefore, the 'Ajuda paralyses' debate also provides a good basis for a discussion on the evolution of the concepts of hysteria and psychosomatic disease and the description of peripheral neuropathy from among a wealth of other entities that did not withstand the test of science.

  11. [Public health services and healthcare workforce in Bakar of the 18th and 19th century].

    PubMed

    Čulina, Tatjana

    2014-01-01

    This review article draws on scarce and poorly studied archival information and several published articles to describe the development and organisation of public health services in the town of Bakar over the 18th and 19th century. For a short while at the turn of the 19th century, Bakar established a hospital run by two physicians and one surgeon to treat patients affected by the so called Škrljevo disease, an endemic type of syphilis. As the century went on, the number of healthcare providers increased by two more physicians, four surgeons, and three to six licensed midwives. There was also a town pharmacy, that worked all that time. As a busy port, the town also provided well-organised maritime sanitary services. As its economy changed over the two centuries to come to a halt after an initial boom, which resulted in a severe drop in population from 7600 to 2000 people, public services deteriorated, including public health. Maritime services suffered the hardest blow, while the workforce gradually came down to one or two physicians and surgeons and several midwives.

  12. Accounts from 19th-century Canadian Arctic explorers' logs reflect present climate conditions

    NASA Astrophysics Data System (ADS)

    Overland, James E.; Wood, Kevin

    The widely perceived failure of 19th-century expeditions to find and transit the Northwest Passage in the Canadian Arctic is often attributed to extraordinary cold climatic conditions associated with the “Little Ice Age” evident in proxy records. However, examination of 44 explorers' logs for the western Arctic from 1818 to 1910 reveals that climate indicators such as navigability, the distribution and thickness of annual sea ice, monthly surface air temperature, and the onset of melt and freeze were within the present range of variability.The quest for the Northwest Passage through the Canadian archipelago during the 19th century is frequently seen as a vain and tragic failure. Polar exploration during the Victorian era seems to us today to have been a costly exercise in heroic futility, which in many respects it was. This perspective has been reinforced since the 1970s, when paleoclimate reconstructions based on Arctic ice core stratigraphy appeared to confirm the existence of exceptionally cold conditions consistent with the period glaciologists had termed the “Little Ice Age” (Figure 1a), with temperatures more than one standard deviation colder relative to an early 20th-century mean [Koerner, 1977; Koerner and Fisher, 1990; Overpeck et al., 1998]. In recent years, the view of the Little Ice Age as a synchronous worldwide and prolonged cold epoch that ended with modern warming has been questioned [Bradley and Jones, 1993; Jones and Briffa, 2001 ;Ogilvie, 2001].

  13. A comparison of 19th century and current attitudes to female sexuality.

    PubMed

    Studd, John

    2007-12-01

    The 19th century medical attitude to normal female sexuality was cruel, with gynecologists and psychiatrists leading the way in designing operations for the cure of the serious contemporary disorders of masturbation and nymphomania. The gynecologist Isaac Baker Brown (1811-1873) and the distinguished endocrinologist Charles Brown-Séquard (1817-1894) advocated clitoridectomy to prevent the progression to masturbatory melancholia, paralysis, blindness and even death. Even after the public disgrace of Baker Brown in 1866-7, the operation remained respectable and widely used in other parts of Europe. This medical contempt for normal female sexual development was reflected in public and literary attitudes. Or perhaps it led and encouraged public opinion. There is virtually no novel or opera in the last half of the 19th century where the heroine with 'a past' survives to the end. H. G. Wells's Ann Veronica and Richard Strauss's Der Rosenkavalier, both of which appeared in 1909, broke the mould and are important milestones. In the last 50 years new research into the sociology, psychology and physiology of sexuality has provided an understanding of decreased libido and inadequate sexual response in the form of hypoactive sexual desire disorder. This is now regarded as a disorder worthy of treatment, either by various forms of counseling or by the use of hormones, particularly estrogens and testosterone.

  14. Extending the African instrumental record to the early 19th century

    SciTech Connect

    Nicholson, S.E.

    1997-11-01

    This paper describes progress toward the production of a data set that extends the African climate record back to the beginning of the 19th century. Qualitative documentary evidence, lake-level fluctuations and other proxy indicators are combined with historical rainfall records to produce regional time series. The data set has relatively high temporal and spatial resolution. The conceptualization is based on a climatic regionalization produced using modern data and an anomaly method in previous historical reconstructions. The data set provides information for some 100 regions with a 1 to 5 year resolution for most of the nineteenth century. Three to five quantitative classes of rainfall are utilized in the data set. Here, the available information to produce this record is summarized. The methodology utilized to combine proxy data and observations to produce a quantitative rainfall data set is described. This historical data set is compared with actual rainfall records for select regions where both are available. This comparison indicates the reliability of the proxy African data set. An analysis of the historical record indicates that the main characteristics of rainfall variability evident in the modern African record are also apparent in the 19th century record. 5 figs.

  15. Human Genetic Variation and Yellow Fever Mortality during 19th Century U.S. Epidemics

    PubMed Central

    2014-01-01

    ABSTRACT We calculated the incidence, mortality, and case fatality rates for Caucasians and non-Caucasians during 19th century yellow fever (YF) epidemics in the United States and determined statistical significance for differences in the rates in different populations. We evaluated nongenetic host factors, including socioeconomic, environmental, cultural, demographic, and acquired immunity status that could have influenced these differences. While differences in incidence rates were not significant between Caucasians and non-Caucasians, differences in mortality and case fatality rates were statistically significant for all epidemics tested (P < 0.01). Caucasians diagnosed with YF were 6.8 times more likely to succumb than non-Caucasians with the disease. No other major causes of death during the 19th century demonstrated a similar mortality skew toward Caucasians. Nongenetic host factors were examined and could not explain these large differences. We propose that the remarkably lower case mortality rates for individuals of non-Caucasian ancestry is the result of human genetic variation in loci encoding innate immune mediators. PMID:24895309

  16. Tuberculosis epidemiology and selection in an autochthonous Siberian population from the 16th-19th century.

    PubMed

    Dabernat, Henri; Thèves, Catherine; Bouakaze, Caroline; Nikolaeva, Dariya; Keyser, Christine; Mokrousov, Igor; Géraut, Annie; Duchesne, Sylvie; Gérard, Patrice; Alexeev, Anatoly N; Crubézy, Eric; Ludes, Bertrand

    2014-01-01

    Tuberculosis is one of most ancient diseases affecting human populations. Although numerous studies have tried to detect pathogenic DNA in ancient skeletons, the successful identification of ancient tuberculosis strains remains rare. Here, we describe a study of 140 ancient subjects inhumed in Yakutia (Eastern Siberia) during a tuberculosis outbreak, dating from the 16(th)-19(th) century. For a long time, Yakut populations had remained isolated from European populations, and it was not until the beginning of the 17(th) century that first contacts were made with European settlers. Subsequently, tuberculosis spread throughout Yakutia, and the evolution of tuberculosis frequencies can be tracked until the 19(th) century. This study took a multidisciplinary approach, examining historical and paleo-epidemiological data to understand the impact of tuberculosis on ancient Yakut population. In addition, molecular identification of the ancient tuberculosis strain was realized to elucidate the natural history and host-pathogen co-evolution of human tuberculosis that was present in this population. This was achieved by the molecular detection of the IS6110 sequence and SNP genotyping by the SNaPshot technique. Results demonstrated that the strain belongs to cluster PGG2-SCG-5, evocating a European origin. Our study suggests that the Yakut population may have been shaped by selection pressures, exerted by several illnesses, including tuberculosis, over several centuries. This confirms the validity and necessity of using a multidisciplinary approach to understand the natural history of Mycobacterium tuberculosis infection and disease.

  17. [From spermatic animalcules to sperm cells: the reconceptualization of generation in the 19th century].

    PubMed

    Vienne, Florence

    2009-09-01

    At the end of the 18th and still at the beginning of the 19th century most naturalists considered spermatic animalcules to be parasites of the seminal fluid that played no role in procreation. This view was progressively questioned by 19th century physiologists. They gradually redefined the spermatic animals as (cellular) products of the male organism, as agents of fertilization and bearers of the male heredity material. This article discusses this change from two different perspectives: on a microhistorical level, it analyzes the experimental research of the naturalist Lazzaro Spallanzani (1729-1799) and of the physiologist Albert Kölliker (1817-1905) in order to show how spermatozoa were turned into a new epistemic object of biology--the sperm cell. Further, it asks how the role of the reconceptualization of spermatic animalcules affected the long-term transformations that gave rise of our modern understanding of heredity, generation and the sexed body. By combining these two perspectives, the article aims to connect historiographies that are often kept separate: the macrohistorical narratives about gender and the body in the modern age and the microhistorical studies of biomedical practices and objects.

  18. [Medecine, Law, and Knowledge Production about the "Civilized" War in the Long 19th Century].

    PubMed

    Goltermann, Svenja

    2015-01-01

    The aim to 'civilize' warfare accompanied Medicine and International Law ever since the mid-19th century. However, the entanglement of Medicine and Law, crucial for such an endeavour, has not been taken into consideration so far; likewise, the huge importance of medical knowledge for the perception of wars and their ramifications did not garner much attention in historical research. Hence, by focusing on the 'long' 19th century, this paper shows, firstly, that the production of surgical knowledge during warfare aimed at measuring the effects of combat on human bodies in order to develop prognostic medical knowledge for future wars, as well as maintaining the combat strength of soldiers. Moreover, this knowledge production during warfare strived for the enhancement of medical competence in the diagnosis and treatment of wounds in general. Secondly, I show that this medical knowledge was not only relevant for warfare, but also crucial for the design of International Law: it served to nourish the debates among the so called 'civilized' nations about legitimate and illegitimate weaponry and warfare.

  19. A history of leprosy in Iran during the 19th and 20th centuries.

    PubMed

    Azizi, Mohammad Hossein; Bahadori, Moslem

    2011-11-01

    From ancient time leprosy has been regarded as a terrifying, stigmatized disease; nevertheless, its cause remained unidentified up to the late 19th century. For centuries numerous leprosy victims worldwide suffered from its morbidity and were socially isolated. The afflicted individuals were segregated because they were considered 'unclean' and had to live in leper colonies, generally under very poor conditions. Physicians believed that leprosy was an incurable, highly contagious, and hereditary disease. In 1873 the Norwegian physician, Gerhard Armauer Hansen (1841-1912), ended the myth of leprosy and discovered its causative agent, known as Mycobacterium leprae. Hansen's discovery was a great triumph in the fight against leprosy. In the 1930's, the first effective antileprosy drug, dapsone, was introduced and in the early 1980's multi-drug therapy was popularized because of high efficacy in resistant cases. Here, we have presented a brief look at the history of leprosy in the world with special focus on the historical account of leprosy in Iran, particularly during the 19th and 20th centuries.

  20. Geometric frustration on a 1/9th site depleted triangular lattice

    NASA Astrophysics Data System (ADS)

    Hopkinson, John; Beck, Jarrett

    2013-03-01

    In the searches both for new spin liquid and spin ice (artificial and macroscopic) candidates, geometrically frustrated two-dimensional spin systems have played a prominent role. Here we present a study of the classical antiferromagnetic Ising (AFI) model on the sorrel net, a 1/9th site depleted and 1/7th bond depleted triangular lattice. The AFI model on this corner-shared triangle net is found to have a large residual entropy per spin S/N = 0 . 48185 +/- 0 . 00008 , indicating the sorrel net is highly geometrically frustrated. Anticipating that it may be difficult to achieve perfect bond depletion, we investigate the physics resulting from turning back on the depleted bonds (J2). We present the phase diagram, analytic expressions for the long range partially ordered ground state spin structure for antiferromagnetic J2 and the short range ordered ground state spin structure for ferromagnetic J2, the magnetic susceptibility and the static structure factor. We briefly comment on the possibility that artificial spin ice on the sorrel lattice could by made, and on a recent report [T. D. Keene et al., Dalton Trans. 40 2983 (2011)] of the creation of a 1/9th depleted cobalt hydroxide oxalate. This work was supported by NSERC (JMH) and NSERC USRA (JJB)

  1. Solar Irradiance from 165 to 400 nm in 2008 and UV Variations in Three Spectral Bands During Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Meftah, M.; Bolsée, D.; Damé, L.; Hauchecorne, A.; Pereira, N.; Irbah, A.; Bekki, S.; Cessateur, G.; Foujols, T.; Thiéblemont, R.

    2016-12-01

    Accurate measurements of the solar spectral irradiance (SSI) and its temporal variations are of primary interest to better understand solar mechanisms, and the links between solar variability and Earth's atmosphere and climate. The SOLar SPECtrum (SOLSPEC) instrument of the Solar Monitoring Observatory (SOLAR) payload onboard the International Space Station (ISS) has been built to carry out SSI measurements from 165 to 3088 nm. We focus here on the ultraviolet (UV) part of the measured solar spectrum (wavelengths less than 400 nm) because the UV part is potentially important for understanding the solar forcing of Earth's atmosphere and climate. We present here SOLAR/SOLSPEC UV data obtained since 2008, and their variations in three spectral bands during Solar Cycle 24. They are compared with previously reported UV measurements and model reconstructions, and differences are discussed.

  2. The response of ozone to solar proton events during solar cycle 21 - The observations

    NASA Technical Reports Server (NTRS)

    Mcpeters, R. D.; Jackman, C. H.

    1985-01-01

    It is pointed out that during a solar proton event (SPE), large numbers of high-energy protons penetrate the earth's mesosphere and upper stratosphere and perturb the normal chemistry by ionizing molecules and changing the balance of odd nitrogen, oxygen, and hydrogen. Changes in ozone caused by an SPE are produced very rapidly, typically in a matter of hours, and are confined to a limited geographic area, the region above 60 deg geomagnetic latitude. In this paper, an analysis is reported of the response of ozone to the significant SPE's in solar cycle 21 from the Nimbus 7 launch in October 1978 to date, using data from the solar backscattered ultraviolet instrument (SBUV). Ozone data during 15 SPE's were examined. It was found that ozone depletion occurred during SPE's on at least five dates.

  3. Unusual Polar Conditions in Solar Cycle 24 and Their Implications for Cycle 25

    NASA Astrophysics Data System (ADS)

    Gopalswamy, Nat; Yashiro, Seiji; Akiyama, Sachiko

    2016-05-01

    We report on the prolonged solar-maximum conditions until late 2015 at the north-polar region of the Sun indicated by the occurrence of high-latitude prominence eruptions (PEs) and microwave brightness temperature close to the quiet-Sun level. These two aspects of solar activity indicate that the polarity reversal was completed by mid-2014 in the south and late 2015 in the north. The microwave brightness in the south-polar region has increased to a level exceeding the level of the Cycle 23/24 minimum, but just started to increase in the north. The north-south asymmetry in the polarity reversal has switched from that in Cycle 23. These observations lead us to the hypothesis that the onset of Cycle 25 in the northern hemisphere is likely to be delayed with respect to that in the southern hemisphere. We find that the unusual condition in the north is a direct consequence of the arrival of poleward surges of opposite polarity from the active region belt. We also find that multiple rush-to-the-pole episodes were indicated by the PE locations that lined up at the boundary between opposite-polarity surges. The high-latitude PEs occurred in the boundary between the incumbent polar flux and the insurgent flux of opposite polarity.

  4. Analysis of Low Temperature Organic Rankine Cycles for Solar Applications

    NASA Astrophysics Data System (ADS)

    Li, Yunfei

    The present work focuses on Organic Rankine Cycle (ORC) systems and their application to low temperature waste heat recovery, combined heat and power as well as off-grid solar power generation applications. As CO_2 issues come to the fore front and fossil fuels become more expensive, interest in low grade heat recovery has grown dramatically in the past few years. Solar energy, as a clean, renewable, pollution-free and sustainable energy has great potential for the use of ORC systems. Several ORC solutions have been proposed to generate electricity from low temperature sources. The ORC systems discussed here can be applied to fields such as solar thermal, biological waste heat, engine exhaust gases, small-scale cogeneration, domestic boilers, etc. The current work presents a thermodynamic and economic analysis for the use of ORC systems to convert solar energy or low exergy energy to generate electrical power. The organic working fluids investigated here were selected to investigate the effect of the fluid saturation temperature on the performance of ORCs. The working fluids under investigation are R113, R245fa, R123, with boiling points between 40°C and 200°C at pressures from 10 kPa to 10 MPa. Ambient temperature air at 20oC to 30oC is utilized as cooling resource, and allowing for a temperature difference 10°C for effective heat transfer. Consequently, the working fluids are condensed at 40°C. A combined first- and second-law analysis is performed by varying some system independent parameters at various reference temperatures. The present work shows that ORC systems can be viable and economical for the applications such as waste heat use and off-grid power generation even though they are likely to be more expensive than grid power.

  5. Observations of Solar Cycle Variations in UV Spectral Irradiance Since 1978

    NASA Astrophysics Data System (ADS)

    Cebula, R. P.; Deland, M. T.

    2010-12-01

    The spectrally resolved amplitude of solar UV irradiance variations over a solar cycle is an important parameter for estimating long-term changes in the Earth’s climate system. Satellite measurements of solar UV variability have been made by at least eight different instruments since 1978, covering both rising and declining phases of solar activity. Determining solar cycle variations from these data sets requires careful consideration of both time-dependent and wavelength-dependent uncertainties for each instrument. We have previously presented irradiance variation results for solar cycles 21, 22, and 23 using spectral irradiance data from Nimbus-7 SBUV, SME, NOAA-9 SBUV/2, NOAA-11 SBUV/2, UARS SUSIM, and UARS SOLSTICE. These results have shown consistent solar cycle irradiance changes within instrumental uncertainties, and also show the same relative spectral dependence for both short-term (rotational) and long-term (solar cycle) variations. In this work, we compare these results to recent UV irradiance data from the SORCE SIM and SORCE SOLSTICE instruments covering the declining phase of Cycle 23. Implementation of the SORCE solar data in atmospheric models leads to substantial changes in stratospheric heating and ozone concentrations compared to previous calculations. We will examine the agreement in solar cycle behavior between different irradiance data sets for their respective time periods, as well as the agreement with proxy model predictions of solar activity.

  6. Evolution of global distribution of the solar wind from cycle 23 to the early phase of cycle 24

    NASA Astrophysics Data System (ADS)

    Tokumaru, Munetoshi; Fujiki, Ken'ichi; Kojima, Masayoshi

    2013-06-01

    Interplanetary scintillation (IPS) observations made with the 327-MHz multi-station system of the Solar-Terrestrial Environment Laboratory (STEL) of Nagoya University are used to investigate long-term evolution of the global solar wind structure. Here, we focus on the recent trend in our data (up to 2011), since peculiar aspects of the cycle 24 have been reported from earlier studies. The IPS data demonstrate that the solar wind systematically changes its global structure with the solar activity cycle, and also that there is some distinct differences in the solar wind structure between the current and past cycles. The fractional area of the fast wind on the source surface significantly increases at low latitudes in the extended minimum between cycle 23 and 24, as compared with that between cycle 22 and 23. This fact is consistent with a marked growth of equatorial coronal holes during the cycle 24. A comparison with magnetograph data of Wilcox Solar Observatory reveals that polar fields have a positive (negative) correlation with fast (slow) wind areas. We find that the solar wind structure in the cycle 24 changes with polar fields following a slightly different track from that of the past cycle. This discrepancy is ascribed to an effect of higher-order moments of the Sun's magnetic field. Another important point revealed from our IPS observations is that solar wind density fluctuations distinctly drop after the extended minimum. This is consistent with a significant reduction in solar wind density observed by in situ measurements during the extended minimum, while our IPS data show that this reduction continues until 2011.

  7. Solar Cycle Modulation of Total Irradiance: an Empirical Model from 1874 to 1988

    NASA Technical Reports Server (NTRS)

    Lean, J.; Foukal, P.

    1990-01-01

    Evidence acquired during the past decade indicates that over time scales of the solar cycle, enhanced emission from bright solar faculae cause significant variations in the sun's total irradiance even though, on shorter time scales, the most pronounced variations are those resulting from the passage of dark sunspots across the solar disc. An empirical model which accounts for the competing effects of dark sunspots and bright faculae has been developed from the available radiometry in cycle 21, and extended back to the beginning of solar cycle 12. According to this model, the largest 11-year modulation of total irradiance during the C20th occurred in the most recent cycle 21.

  8. Thermal stress cycling of GaAs solar cells

    NASA Astrophysics Data System (ADS)

    Janousek, B. K.; Francis, R. W.; Wendt, J. P.

    A thermal cycling experiment was performed on GaAs solar cells to establish the electrical and structural integrity of these cells under the temperature conditions of a simulated low-Earth orbit of 3-year duration. Thirty single junction GaAs cells were obtained and tests were performed to establish the beginning-of-life characteristics of these cells. The tests consisted of cell I-V power output curves, from which were obtained short-circuit current, open circuit voltage, fill factor, and cell efficiency, and optical micrographs, spectral response, and ion microprobe mass analysis (IMMA) depth profiles on both the front surfaces and the front metallic contacts of the cells. Following 5,000 thermal cycles, the performance of the cells was reexamined in addition to any factors which might contribute to performance degradation. It is established that, after 5,000 thermal cycles, the cells retain their power output with no loss of structural integrity or change in physical appearance.

  9. Sources of Geomagnetic Activity during Nearly Three Solar Cycles (1972-2000)

    NASA Technical Reports Server (NTRS)

    Richardson, I. G.; Cane, H. V.; Cliver, E. W.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We examine the contributions of the principal solar wind components (corotating highspeed streams, slow solar 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 solar cycles. A prime motivation is to understand the influence of solar cycle variations in solar 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 solar minimum, while at solar maximum, structures associated with transients make the largest contribution (approx. 50%), though contributions from streams and slow solar wind continue to be present. Similarly, high-speed streams are the principal contributor (approx. 55%) to solar minimum averages of the IMF, while transient-related structures are the leading contributor (approx. 40%) at solar maximum. These differences between solar maximum and minimum reflect the changing structure of the near-ecliptic solar wind during the solar cycle. For minimum periods, the Earth is embedded in high-speed streams approx. 55% of the time versus approx. 35% for slow solar wind and approx. 10% for CME-associated structures, while at solar maximum, typical percentages are as follows: high-speed streams approx. 35%, slow solar 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 solar wind over the solar 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 solar cycle averages, we show that high-speed streams account for approx. 44%, approx. 48%, and approx. 40% of the solar

  10. Properties of Magnetic Tongues over a Solar Cycle

    NASA Astrophysics Data System (ADS)

    Poisson, Mariano; Démoulin, Pascal; López Fuentes, Marcelo; Mandrini, Cristina H.

    2016-08-01

    The photospheric spatial distribution of the main magnetic polarities of bipolar active regions (ARs) present during their emergence deformations are known as magnetic tongues. They are attributed to the presence of twist in the toroidal magnetic-flux tubes that form the ARs. The aim of this article is to study the twist of newly emerged ARs from the evolution of magnetic tongues observed in photospheric line-of-sight magnetograms. We apply the procedure described by Poisson et al. ( Solar Phys. 290, 727, 2015a) to ARs observed over the full Solar Cycle 23 and the beginning of Cycle 24. Our results show that the hemispherical rule obtained using the tongues as a proxy of the twist has a weak sign dominance (53 % in the southern hemisphere and 58 % in the northern hemisphere). By defining the variation of the tongue angle, we characterize the strength of the magnetic tongues during different phases of the AR emergence. We find that there is a tendency of the tongues to be stronger during the beginning of the emergence and to become weaker as the AR reaches its maximum magnetic flux. We compare this evolution with the emergence of a toroidal flux-rope model with non-uniform twist. The variety of evolution of the tongues in the analyzed ARs can only be reproduced when using a broad range of twist profiles, in particular having a large variety of twist gradients in the direction vertical to the photosphere. Although the analytical model used is a special case, selected to minimize the complexity of the problem, the results obtained set new observational constraints to theoretical models of flux-rope emergence that form bipolar ARs.

  11. A chaotic model for the plague epidemic that has occurred in Bombay at the end of the 19th century

    NASA Astrophysics Data System (ADS)

    Mangiarotti, Sylvain

    2015-04-01

    The plague epidemic that has occurred in Bombay at the end of the 19th century was detected in 1896. One year before, an Advisory Committee had been appointed by the Secretary of State for India, the Royal Society, and the Lister Institute. This Committee made numerous investigations and gathered a large panel of data including the number of people attacked and died from the plague, records of rat and flea populations, as well as meteorological records of temperature and humidity [1]. The global modeling technique [2] aims to obtain low dimensional models able to simulate the observed cycles from time series. As far as we know, this technique has been tried only to one case of epidemiological analysis (the whooping cough infection) based on a discrete formulation [3]. In the present work, the continuous time formulation of this technique is used to analyze the time evolution of the plague epidemic from this data set. One low dimensional model (three variables) is obtained exhibiting a limit cycle of period-5. A chaotic behavior could be derived from this model by tuning the model parameters. It provides a strong argument for a dynamical behavior that can be approximated by low dimensional deterministic equations. This model also provides an empirical argument for chaos in epidemics. [1] Verjbitski D. T., Bannerman W. B. & Kápadiâ R. T., 1908. Reports on Plague Investigations in India (May,1908), The Journal of Hygiene, 8(2), 161 -308. [2] Mangiarotti S., Coudret R., Drapeau L. & Jarlan L., 2012. Polynomial search and Global modelling: two algorithms for modeling chaos. Physical Review E, 86(4), 046205. [3] Boudjema G. & Cazelles B., 2003. Extraction of nonlinear dynamics from short and noisy time series. Chaos, Solitons and Fractals, 12, 2051-2069.

  12. Analysis of Polar Reversals of Solar Cycle 22 and 23

    NASA Astrophysics Data System (ADS)

    Ettinger, Sophie

    2015-01-01

    We study the relationship between polar field reversals and decayed active region magnetic flux. Photospheric active region flux is dispersed by differential rotation and turbulent diffusion, and is transported poleward by meridional flows and diffusion. We investigate in detail the relationship between the transport of decayed active region flux to high latitudes and changes in the polar field strength, including reversals in the magnetic polarity at the poles. By means of stack plots of low- and high-latitude slices of synoptic magnetograms, one to three activity complexes (systems of active regions) were identified in each reversal as the main cause of polar field reversals in each cycle. The poleward transport of large quantities of decayed lagging-polarity flux from these complexes was found to correlate well in time with the polar field changes. In each case significant latitudinal displacements were found between the positive and negative flux centroids of the complexes, consistent with Joy's law bipole tilt with lagging-polarity flux located poleward of leading-polarity flux. This result indicates the importance of the Joy's law tilt and consequent high-latitude polarity bias in polar reversals.This work is carried out through the National Solar Observatory Summer Research Assistantship (SRA) Program. The National Solar Observatory is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation.

  13. EDITORIAL: The 19th MicroMechanics Europe Workshop (MME 2008) The 19th MicroMechanics Europe Workshop (MME 2008)

    NASA Astrophysics Data System (ADS)

    Schnakenberg, Uwe

    2009-07-01

    This special issue of Journal of Micromechanics and Microengineering is devoted to the 19th MicroMechanics Europe Workshop (MME 08), which took place at the RWTH Aachen University, Aachen, Germany, from 28-30 September, 2008. The workshop is a well recognized and established European event in the field of micro system technology using thin-film technologies for creating micro components, micro sensors, micro actuators, and micro systems. The first MME Workshop was held 1989 in Enschede (The Netherlands) and continued 1990 in Berlin (Germany), 1992 in Leuven (Belgium), and then was held annually in Neuchâtel (Switzerland), Pisa (Italy), Copenhagen (Denmark), Barcelona (Spain), Southampton (UK), Ulvik in Hardanger (Norway), Gif-sur-Yvette (France), Uppsala (Sweden), Cork (Ireland), Sinaia (Romania), Delft (The Netherlands), Leuven (Belgium), Göteborg (Sweden), Southampton (UK), and in Guimarães (Portugal). The two day workshop was attended by 180 delegates from 26 countries all over Europe and from Armenia, Austria, Bulgaria, Canada, China, Cuba, Iran, Japan, Korea, Malaysia, Taiwan, Turkey, and the United States of America. A total of 97 papers were accepted for presentation and there were a further five keynote presentations. I am proud to present 22 high-quality papers from MME 2008 selected for their novelty and relevance to Journal of Micromechanics and Microengineering. All the papers went through the regular reviewing procedure of IOP Publishing. I am eternally grateful to all the referees for their excellent work. I would also like to extend my thanks to the members of the Programme Committee of MME 2008, Dr Reinoud Wolffenbuttel, Professor José Higino Correia, and Dr Patrick Pons for pre-selection of the papers as well as to Professor Robert Puers for advice on the final selection of papers. My thanks also go to Dr Ian Forbes of IOP Publishing for managing the entire process and to the editorial staff of Journal of Micromechanics and Microengineering. I

  14. Paths to and from poverty in late 19th century novels

    PubMed Central

    Howden‐Chapman, Philippa; Kawachi, Ichiro

    2006-01-01

    Late 19th century novels provide graphic descriptions of working and living conditions and their impact on population health, in particular the detrimental effects of hunger, poor housing, environmental conditions, hazardous work and poor pay, smoking and alcohol and crime, but also the transformative possibilities of social and political action. The popularity of these novels helped raise the collective conscience of citizens and illuminated the direction for 20th century welfare reforms. Yet many of these problems remain and the pathways to and from poverty are still recognisable today. Although novels are now less central in conveying social information, re‐reading these novels enables us to understand how social and economic circumstances were understood at the time and what led to social and political change. PMID:16415257

  15. Following rules in the intermontane west: 19th-century mormon settlement.

    PubMed

    Norton, W

    2001-01-01

    The academic discipline of human geography is concerned with human activities, especially as these relate to physical landscapes and contribute to the modification of those landscapes. Although little attention has been paid to objectivist philosophies to inform human geography, behavior analysis might offer a useful explanatory model. As an example, a behavior analysis of selected aspects of 19th-century Mormon movement and settlement in the intermontane West is conducted. Mormons are a society of believers who practice cooperative effort and support for other members, and the Mormon church is governed by priesthood authority with members being called to perform tasks. This analysis employs the concepts of metacontingency, rule-governed behavior, and delayed reinforcement to analyze how Mormons settled the intermontane West.

  16. Electrical treatment of spinal cord injuries in the 18th and 19th centuries.

    PubMed

    Silver, John R; Weiner, M-F

    2013-05-01

    Two centuries ago, electricity was being used for the treatment of paraplegia and trials were taking place in France. This study aims to identify cases of traumatic paraplegia treated with electricity in the 19th century in order to assess the therapeutic benefit. Only four such cases were identified, none with a complete transection of the spinal cord since these patients would have died from pressure sores and urinary tract infections. The personalities involved, William Gull, William Erb, Guillaume Duchenne and Cyril Henry Golding Bird are portrayed and contemporaneous views on electrotherapy analysed. While the four patients apparently benefited from the treatment, the lack of follow-up and the incomplete data prevented a definitive conclusion on the therapeutic value of electrical treatment in traumatic paraplegia.

  17. Apothecary activity in Dubrovnik Dominican Monastery from 17th to the beginning 19th century.

    PubMed

    Krasic, Stjepan

    2011-01-01

    The origin of the Dominican monastery pharmacy is not clear, but sources suggest that it had operated from the eve of the great earthquake in Dubrovnik in 1667 to the beginning of the 19th century. Its last pharmacist, praised for his competence, passed away in 1803, leaving no one behind The prior travelled all the way to Naples to find a competent pharmacist in his stead, but never returned. Story has it that on the way back, the abbot and the pharmacist lost their lives in a shipwreck. The French army occupied the town in 1806, and the monastery was turned into a military camp. Following the retreat of the French army in 1814, the monastery was returned to the Dominicans, but the pharmacy was never restored.

  18. Height of female Americans in the 19th century and the antebellum puzzle.

    PubMed

    Carson, Scott Alan

    2011-03-01

    Using 19th century state prison records, this study contrasts the biological standard of living of comparable US African-American and white females during a period of relatively rapid economic development. White females were consistently taller than black females by about 1.5 cm (0.6 in.). Whites from Great Lakes and Plains states and black Southwestern females were the tallest. US females were tall compared to their European counterparts. The height of females began to decline in the antebellum period, possibly before that of males. The recovery of physical stature was also earlier among females than among males. This implies that the biological standard of lower-class men and women did not move in parallel during the onset of modern economic growth. It also implies that the antebellum puzzle was most likely rooted in the endogenous forces of socio-economic change rather than the exogenous changes in the disease environment.

  19. Placenta Accreta and Total Placenta Previa in the 19th Week of Pregnancy.

    PubMed

    Findeklee, S; Costa, S D

    2015-08-01

    Placentation disorders are the result of impaired embedding of the placenta in the endometrium. The prevalence of these disorders is estimated to be around 0.3 %. A history of previous prior uterine surgery (especially cesarean section and curettage) is the most common risk factor. Impaired placentation is differentiated into deep placental attachment; marginal, partial and total placenta previa; and placenta accreta, increta and percreta. Treatment depends on the severity of presentation and ranges from expectant management to emergency hysterectomy. In most cases, preterm termination of pregnancy is necessary. We report here on the case of a 39-year-old woman with placenta accreta and total placenta previa who underwent hysterectomy in the 19th week of pregnancy.

  20. [Healthcare in times of epidemics in Rio de Janeiro in the 19th century].

    PubMed

    Pimenta, Tânia Salgado

    2011-01-01

    This article aims to examine the provision of healthcare for the population of Rio de Janeiro in the mid-19th century and describe its reorganization during the crisis caused by outbreaks of yellow fever and cholera. In this context, it is essential to consider the significant changes taking place in healthcare during this period, also affecting the spaces in which hospital care was offered. Therefore, we focussed our investigation on Santa Casa da Misericórdia Hospital, the most important hospital in the capital of the Brazilian Empire. The sources used are the correspondence between the government and the hospital, the hospital annual reports, archives of the Central Board of Public Hygiene, and wide-circulation medical journals.

  1. Following rules in the intermontane west: 19th-century mormon settlement

    PubMed Central

    Norton, William

    2001-01-01

    The academic discipline of human geography is concerned with human activities, especially as these relate to physical landscapes and contribute to the modification of those landscapes. Although little attention has been paid to objectivist philosophies to inform human geography, behavior analysis might offer a useful explanatory model. As an example, a behavior analysis of selected aspects of 19th-century Mormon movement and settlement in the intermontane West is conducted. Mormons are a society of believers who practice cooperative effort and support for other members, and the Mormon church is governed by priesthood authority with members being called to perform tasks. This analysis employs the concepts of metacontingency, rule-governed behavior, and delayed reinforcement to analyze how Mormons settled the intermontane West. PMID:22478355

  2. The Rise of Commercial Telescope Making in 19th Century America

    NASA Astrophysics Data System (ADS)

    Launie, Kenneth J.

    2009-01-01

    Very few telescopes were made in America in the 18th century; astronomers needed to rely on distant European makers. While there is evidence of a few American craftsman-made telescopes that were shown at early to mid-19th century Mechanics' Fairs, Massachusetts native Amasa Holcomb appears to have been the first to offer them for sale commercially. Most of Holcomb's instruments were Herschelian reflectors with speculum metal mirrors. Henry Fitz started his optical career by making mirrors used for the first Daguerreotype portrait cameras, and by the mid 1840's he was offering refractors of ever-increasing size. Not long after Fitz started, Alvan Clark began selling telescopes, and the premature death of Fitz in 1863 may have aided Alvan Clark and Sons' rise to prominence. The later decades of the 1800s saw a dramatic increase in the number of college observatories, and with that came more manufacturers to supply the demand.

  3. [Brain physiology and the development of psychiatry in the 19th century].

    PubMed

    Alvarez Pelaez, R

    1993-01-01

    Great developments in study of the central and peripheral nervous system took place throughout the 19th century, especially in Britain. These studies, together with other factors, gave rise to the development of a somaticism of mental illness. The followers of this school of thought, most notably Henry Maudsley, supported the idea of materialism, based on the theory of evolution. They were opposed by those who believed in the duality of body and mind whith its different variants. These two visions constituted the centre of the theoretical debate of psychiatry at that time. The author pays special attention to the first stance and reaches the conclusion that this process of knowledge made mental illness to be considered as an organic disease and contribuited to the entry of the lunatic wholly into the sphere or medical action.

  4. Prospects for using sonar for underwater archeology on the Yenisei: surveying a 19th century shipwreck

    NASA Astrophysics Data System (ADS)

    Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

    2016-11-01

    Current progress in underwater archeology is based on a rich arsenal of high-tech appliances, among which sonar technology plays a key role; it enables scientists not only to detect submerged archeological objects, but to examine them in high definition without having to conduct diving operations or use expensive underwater unmanned vehicles. While the majority of sensational scientific discoveries using sonar have been made in saltwater environments, freshwater ones, rivers in particular, have seen limited activity. The river Yenisei in central Siberia contains an unrecorded number of shipwrecks that await being discovered and studied. In this article we focus on the peculiarities of using sonar for detecting archeological sites on the Yenisei. This article is based on the results of the 2016 expedition, which has determined the location of Thames, a 19th century British steam schooner which was wrecked on the Yenisei.

  5. Lockyer's "Astronomy" among Serbs in the second half of the 19th century.

    NASA Astrophysics Data System (ADS)

    Trajkovska, V.; Ninković, S.

    1997-08-01

    The dynamical development of astronomy in the second half of 19th century has also found its adequate response among Serbs. As a good example may serve, in the opinion of the present authors, the translation of "Astronomy" by N. Lockyer into Serbian (the book was printed in 1880 in Novi Sad). The translator was Djordje Natošević who translated not the English original, but the German translation. The authors find Natošević an interesting personality. A physician by education he devoted the best part of his life to pedagogy and to enhancing the educational level in Serbian primary and secondary schools in Austria-Hungary of those days. He spent some time also in Serbia. It was then that he translated from German the textbook "Astronomy" by Lockyer, popular in those days.

  6. Geoeffectiveness of solar eruptions during the rising phase of solar cycle 24

    NASA Astrophysics Data System (ADS)

    Bisht, Hema; Pande, Bimal; Chandra, Ramesh; Pande, Seema

    2017-02-01

    This paper presents a statistical analysis of different parameters responsible for the geoeffectiveness of solar eruptions during the rising phase of solar cycle 24. We have selected 33 halo CME events from the beginning of the current solar cycle 24 (2009-2013). The levels of geomagnetic activity are categorized into two groups based on the observed minimum Dst index, i.e., moderate (-100 nT < Dst ≤ -50 nT) and intense (Dst ≤ -100nT). The parameters are represented graphically and analyzed statistically. The Spearman rank correlation coefficient between Dst index and CME speed is 0.02 with a P-value 0.91 (much higher than 0.05) and between Dst index and X-ray flux of flares is 0.13 with a P-value 0.48 (higher than 0.05), which shows that high speed CMEs and big flares are not the effective and significant parameters for geoeffectiveness of these selected halo events. The Spearman rank correlation coefficient between CME speed and X-ray flux is better, i.e., 0.38 and the P-value is equal to 0.03 (less than 0.05), which clearly implies that big flares are responsible for producing high speed CMEs and both parameters share a significant relationship . The source location of geoeffective halo CME events exhibit N-S asymmetry.

  7. Reconstructions of global near-surface temperature change since the mid 19th century

    NASA Astrophysics Data System (ADS)

    Morice, Colin; Rayner, Nick; Kennedy, John

    2016-04-01

    Incomplete and non-uniform global observational coverage is a prominent source of uncertainty in instrumental records of global near-surface temperature change. In this study statistical methods are applied to the HadCRUT4 near-surface temperature data set to obtain improved estimates of global near-surface temperature change since the mid 19th century. Methods applied include those that interpolate according to local correlation structure (kriging) and reduced space methods that learn large-scale temperature patterns. The performance of each statistical reconstruction method has been benchmarked in application to a subset of CMIP5 simulations. Model fields are sub-sampled and simulated observational errors added to emulate observational data, permitting assessment of temperature field reconstruction algorithms in controlled tests in which globally complete temperature fields are known. In application to HadCRUT4 data the statistical reconstructions show relatively increased warming in the global average over the 21st century owing to reconstruction of temperatures in high northern latitudes, supporting the findings of Cowtan & Way (2014) and Karl et al. (2015). There is broad agreement between estimates of global and hemispheric changes throughout much of the 20th and 21st century. Agreement is reduced in data sparse periods and regions, notably in the 19th century and in the southern hemisphere. This finding is supported by the results of the climate model based benchmarks and highlights the importance of continued data rescue activities, such as those of the International Surface Temperature Initiative and ACRE. The results of this study will form an addition to the HadCRUT4 global near-surface temperature data set.

  8. Ochres and earths: matrix and chromophores characterization of 19th and 20th century artist materials.

    PubMed

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-15

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

  9. Ochres and earths: Matrix and chromophores characterization of 19th and 20th century artist materials

    NASA Astrophysics Data System (ADS)

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-01

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

  10. Science Fiction In Naples In The Middle Of The 19th Century

    NASA Astrophysics Data System (ADS)

    Capaccioli, Massimo; Cirella, Emilia Olostro; Stendardo, Enrica; Virgilio, Nicla

    Astronomer, intellectual, passionate patriot, and refined humanist, Ernesto Capocci Belmonte (Picinisco, May 31, 1798 - Naples, January 6, 1864) was a prominent figure of the scientific, cultural, and political life in Naples around the middle of the 19th century. He acquired international recognition for his studies on the orbits of comets and, since 1833, he was named director of the newly built Osservatorio Astronomico in Capodimonte: A prestigious position that he lost for political retaliation as a result of his participation in the movement against the Bourbon rulers in 1848, but which he regained in 1860 upon the arrival in Naples of Giuseppe Garibaldi. An intuitive and open-minded scholar, he looked always at the contemporary experiences in Europe and, as a scientist and cultivated human being, he sought to serve the community by enthusiastically devoting himself also to education and public outreach. He developed clear interests in literature and, as a forerunner, he dared to tackle the genre of science fiction. His short novel Relazione del viaggio alla Luna fatto da una donna nell'anno di grazia 2057 (Report of the Trip to the Moon done by a Woman in the Year of our Lord 2057), written in the period of his exile from the Observatory and practically given up as lost until a private copy was found in the library of one of Capocci's descendants, offers an interesting overview of astronomical knowledge and taste for the elegance in writing, and gives an unusual, and often ironic, viewpoint on the situation of sciences in Naples in the middle of the 19th century.

  11. Reading The Sun: A Three Dimensional Visual Model of The Solar Environment During Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Carranza-fulmer, T. L.; Moldwin, M.

    2014-12-01

    The sun is a powerful force that has proven to our society that it has a large impact on our lives. Unfortunately, there is still a lack of awareness on how the sun is capable of affecting Earth. The over all idea of "Reading The Sun" installation is to help demonstrate how the sun impacts the Earth, by compiling various data sources from satellites (SOHO, SDO, and STERO) with solar and solar wind models (MAS and ENLIL) to create a comprehensive three dimensional display of the solar environment. It focuses on the current solar maximum of solar cycle 24 and a CME that impacted Earth's magnetic field on February 27, 2014, which triggered geomagnetic storms around the Earth's poles. The CME was an after-effect of a class X4.9 solar flare, which was released from the sun on February 25, 2014. "Reading The Sun" is a 48" x 48" x 48" hanging model of the sun with color coded open opposing magnetic field lines along with various layers of the solar atmosphere, the heliospheric current sheet, and the inner planets. At the center of the xyz axis is the sun with the open magnetic field lines and the heliospheric current sheet permeating inner planetary space. The xyz axes are color coded to represent various types of information with corresponding visual images for the viewer to be able to read the model. Along the z-axis are three colors (yellow, orange, and green) that represent the different layers of the solar atmosphere (photosphere, chromosphere, and corona) that correspond to three satellite images in various spectrums related to a CME and Solar Flare and the xy-plane shows where the inner planets are in relation to the sun. The exhibit in which "Reading The Sun "is being displayed is called, The Rotation of Language at the Wheather Again Gallery in Rockaway, New York. The intent of the exhibit is to both celebrate as well as present a cautionary tale on the ability of human language to spark and ignite the individual and collective imagination towards an experience

  12. Near-Earth Solar Wind Flows and Related Geomagnetic Activity During more than Four Solar Cycles (1963-2011)

    NASA Technical Reports Server (NTRS)

    Richardson, Ian G.; Cane, Hilary V.

    2012-01-01

    In past studies, we classified the near-Earth solar wind into three basic flow types based on inspection of solar 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 solar 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 solar 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 solar wind observations, thereby encompassing the complete solar cycles 20 to 23 and the ascending phase of cycle 24. We discuss the cycle-to-cycle variations in near-Earth solar wind structures and l1e related geomagnetic activity over more than four solar cycles, updating some of the results of our earlier studies.

  13. A study of density modulation index in the inner heliospheric solar wind during solar cycle 23

    SciTech Connect

    Bisoi, Susanta Kumar; Janardhan, P.; Ingale, M.; Subramanian, P.; Ananthakrishnan, S.; Tokumaru, M.; Fujiki, K. E-mail: jerry@prl.res.in E-mail: p.subramanian@iiserpune.ac.in E-mail: tokumaru@stelab.nagoya-u.ac.jp

    2014-11-01

    The ratio of the rms electron density fluctuations to the background density in the solar wind (density modulation index, ε {sub N} ≡ ΔN/N) is of vital importance for understanding several problems in heliospheric physics related to solar wind turbulence. In this paper, we have investigated the behavior of ε {sub N} in the inner heliosphere from 0.26 to 0.82 AU. The density fluctuations ΔN have been deduced using extensive ground-based observations of interplanetary scintillation at 327 MHz, which probe spatial scales of a few hundred kilometers. The background densities (N) have been derived using near-Earth observations from the Advanced Composition Explorer. Our analysis reveals that 0.001 ≲ ε {sub N} ≲ 0.02 and does not vary appreciably with heliocentric distance. We also find that ε {sub N} declines by 8% from 1998 to 2008. We discuss the impact of these findings on problems ranging from our understanding of Forbush decreases to the behavior of the solar wind dynamic pressure over the recent peculiar solar minimum at the end of cycle 23.

  14. Using dynamo theory to predict the sunspot number during solar cycle 21

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Scherrer, P. H.; Svalgaard, L.; Wilcox, J. M.

    1978-01-01

    On physical grounds it is suggested that the polar field strength of the sun near a solar minimum is closely related to the solar activity of the following cycle. Four methods of estimating the polar magnetic field strength of the sun near solar minimum are employed to provide an estimate of the yearly mean sunspot number of cycle 21 at solar maximum of 140 + or - 20. This estimate may be considered a first-order attempt to predict the cycle activity using one parameter of physical importance based upon dynamo theory.

  15. Explaining solar cycle effects on composition as it relates to the winter anomaly

    NASA Astrophysics Data System (ADS)

    Burns, A. G.; Solomon, S. C.; Wang, W.; Qian, L.; Zhang, Y.; Paxton, L. J.; Yue, X.; Thayer, J. P.; Liu, H. L.

    2015-07-01

    The solar cycle variation of F2 region winter anomaly is related to solar cycle changes in the latitudinal winter-to-summer difference of O/N2. Here we use the National Center for Atmospheric Research-Global Mean Model to develop a concept of why the latitudinal winter-to-summer difference of O/N2 varies with solar cycle. The main driver for these seasonal changes in composition is vertical advection, which is expressed most simply in pressure coordinates. Meridional winds do not change over the solar cycle, so the vertical winds should also not change. The other component of vertical advection is the vertical gradient of composition. Is there any reason that this should change? At solar maximum vertical temperature gradients between 100 and 200 km altitude are strong, whereas they are weak at solar minimum. To maintain the same pressure, the weak vertical temperature gradients at solar minimum must be balanced by weak density gradients and the strong temperature gradients at solar maximum must be balanced by strong density gradients to obtain the same pressure profile. Changes in the vertical density gradients are species dependent: heavy species change more and light species change less than the average density change. Hence, vertical winds act on stronger O/N2 gradients at solar maximum than they do at solar minimum, and a stronger winter-to-summer difference of O/N2 occurs at solar maximum compared with solar minimum.

  16. Predictions of the onset of mini ice age in the 25th solar cycle

    NASA Astrophysics Data System (ADS)

    Kumar, Rajiv

    2016-07-01

    Predictions of the ir-regularty in the 11 year heartbeat of the sun due to asyncronous of the two layered dynamo effect would result in mini ice age as in the Maunder minimum.The onset of this event is expected in the begining of 25th solar cycle and would go to its maximum in the 26th solar cycle.The minimum temperature is expected in 2028 due to the fall of solar activity by 60 % termed as solar hibernation.The predictions are based on the observations obtained by the Royal Greenwich observatory since 1874. Keywords: Dynamo effect,munder minimum,Solar hybernation

  17. The solar diameter is most probably constant over the solar cycle

    NASA Astrophysics Data System (ADS)

    Damé, Luc

    We analyzed 7 years of filtregrams data (150000 photograms and magnetograms) of the SOHO/MDI experiment. We used the maximum possible sampling compatible with full frame recording, carefully avoiding any suspicious filtregram. Going further than the previous analysis of Emilio et al. (Ap. J. 543, 2000) and Kuhn et al. (Ap. J. 613, 2004) we better corrected for changes in optical aberrations and, along Turmon et al. (Ap. J., 568, 396, 2002), we reduced radius measurement errors by identifying active regions from magnetograms and by avoiding radius measurements herein. We found that, within the limit of our noise level uncertainties (8 to 9 mas), the solar diameter is compatible with constancy over the half cycle investigated. Our results confirm the reanalysis of the 7 years of MDI data of Antia (Ap. J. 590, 2003), with a completely different method since using the ultra-precise frequency variation of the f-modes (fundamental modes linked to the diameter), who found (carefully removing the yearly Earth induced variations and avoiding the SOHO data gap of 1999) that the diameter is constant over the half solar cycle (radius variation are less than 0.6 km, 0.8 mas -nothing over noise level). We can conclude, along Antia, that: "If a careful analysis is performed, then it turns out that there is no evidence for any variation in the solar radius." There were no theoretical reasons for large solar radius variations and there is no observational evidence for them with consistent space observations made with 3 different approaches.

  18. Rotation of solar magnetic fields for the current solar cycle 24

    SciTech Connect

    Shi, X. J.; Xie, J. L.

    2014-11-01

    The rotation of solar magnetic fields for the current solar cycle 24 is investigated through a cross-correlation analysis of the Carrington synoptic maps of solar photospheric magnetic fields during Carrington rotation numbers 2076-2146 (2008 October to 2014 January). The sidereal rotation rates of positive and negative magnetic fields at some latitudes are shown, and it can be found that the positive (negative) fields generally rotate faster than the negative (positive) fields in the southern (northern) hemisphere at low latitudes. The mean rotation profiles of total, positive, and negative magnetic fields between ±60° latitudes in the time interval are also obtained. It should be noted that both of the mean rotation profiles of the positive and negative magnetic fields, as well as the mean rotation profile of the total magnetic field, exhibit a quasi-rigid rotation at latitudes above about 55°. The mean rotation rates of the positive (negative) polarity reach their maximum values at about 9°(6)° latitude in the southern (northern) hemisphere. The mean rotation profile of the total magnetic field displays an obvious north-south asymmetry, where the rotation seems to be more differential in the northern hemisphere. The latitude variation in the rotation rate differences between positive and negative magnetic fields is further studied, and it is found that magnetic fields with the same polarity as the leading sunspots at a given hemisphere rotate faster than those with the opposite polarity, except for the zones around 52° latitude of the southern hemisphere and around 35° latitude of the northern hemisphere. The implication of these results is discussed. It is clear that the obtained results can provide some observational constraints on the theoretical research of the mechanisms of differential rotation and solar cycle.

  19. Evolution of the 155 day periodicity in sunspot areas during solar cycles 12 to 21

    SciTech Connect

    Lean, J. )

    1990-11-01

    Sunspot area data during solar cycles 12-21 are examined with both periodogram and evolutionary spectral analysis techniques for evidence of a periodicity near 155 days. This periodicity is found to be present only during epochs of maxium activity, when it modulates the sunspot areas by as much as 15-20 percent of the amplitude of the 11 yr cycle. The 155 day periodicity typically occurs in episodes of from 1 to 3 yr, with sequential episodes often in opposite solar hemispheres; the strengths of these episodes appear to track the general level of solar activity. Comparing the phases of sinusoids fitted to the sunspot area data within individual solar cycles provides evidence for coherency within + or - 8 days of a period at 155 days between solar cycles 19, 20, and 21. However, within any one episode the actual period of the 155 day cycle may drift from 130 to 185 days. 31 refs.

  20. Prediction of the smoothed monthly mean sunspot numbers for solar cycle 24

    NASA Astrophysics Data System (ADS)

    Wang, Jialong; Miao, Juan; Liu, Siqing; Gong, Jiancun; Zhu, Cuilian

    2008-12-01

    The prediction for the smoothed monthly mean sunspot numbers (hereafter SMSNs) of solar cycle 23, which was given with a similar cycle method proposed by us at the beginning time of cycle 23, is analyzed and verified in this paper. Using our predicted maximum SMSN and the ascending length for solar cycle 24, and assuming their relative errors to be respectively 20% and ± 7 months, solar cycles 2, 4, 8, 11, 17, 20 and 23 are selected to be the similar cycles to cycle 24. The selected solar cycles are divided into two groups. The first group consists of all the selected cycles; while the second group consists of only cycles 11, 17, 20 and 23. Two SMSN time profiles then may be obtained, respectively, for the two similar cycle groups. No significant difference is found between the two predicted time profiles. Considering the latest observed sunspot number so far available for cycle 23 and the predictions for the minimum SMSN of cycle 24, a date calibration is done for the obtained time profiles, and thus, SMSNs for 127 months of cycle 24, from October 2007 to April 2018, are predicted.

  1. Distribution of the activity of the Sun during an average solar cycle

    NASA Astrophysics Data System (ADS)

    Svoreň, J.

    2015-12-01

    The paper offers a look at distribution of solar activity during an average solar cycle. Activity profiles in solar cycles from 13 to 17 and from 18 to 22 were studied based on the relative sunspot numbers. The average values for both groups of cycles were derived after the standardization to the maximum monthly value. Obtained values differed minimally, allowing us to derive a uniform distribution of activity for the entire review period from 1890 to 1996. The derived model of the distribution of activity in an average solar cycle allows us to predict the maximum value of an activity cycle with an advance of approximately 5 years based only on the value obtained in the first year of the cycle. This can be of use for, e.g., the planning of long-term human activities in outer space.

  2. Semi-annual Sq-variation in solar activity cycle

    NASA Astrophysics Data System (ADS)

    Pogrebnoy, V.; Malosiev, T.

    The peculiarities of semi-annual variation in solar activity cycle have been studied. The data from observatories having long observational series and located in different latitude zones were used. The following observatories were selected: Huancayo (magnetic equator), from 1922 to 1959; Apia (low latitudes), from 1912 to 1961; Moscow (middle latitudes), from 1947 to 1965. Based on the hourly values of H-components, the average monthly diurnal amplitudes (a difference between midday and midnight values), according to five international quiet days, were computed. Obtained results were compared with R (relative sunspot numbers) in the ranges of 0-30R, 40-100R, and 140-190R. It was shown, that the amplitude of semi-annual variation increases with R, from minimum to maximum values, on average by 45%. At equatorial Huancayo observatory, the semi-annual Sq(H)-variation appears especially clearly: its maximums take place at periods of equinoxes (March-April, September-October), and minimums -- at periods of solstices (June-July, December-January). At low (Apia observatory) and middle (Moscow observatory) latitudes, the character of semi-annual variation is somewhat different: it appears during the periods of equinoxes, but considerably less than at equator. Besides, with the growth of R, semi-annual variation appears against a background of annual variation, in the form of second peaks (maximum in June). At observatories located in low and middle latitudes, second peaks become more appreciable with an increase of R (March-April and September-October). During the periods of low solar activity, they are insignificant. This work has been carried out with the support from International Scientific and Technology Center (Project #KR-214).

  3. Helioseismic inferences of the solar cycles 23 and 24: GOLF and VIRGO observations

    NASA Astrophysics Data System (ADS)

    Salabert, D.; García, R. A.; Jiménez, A.

    2014-12-01

    The Sun-as-a star helioseismic spectrophotometer GOLF and photometer VIRGO instruments onboard the SoHO spacecraft are collecting high-quality, continuous data since April 1996. We analyze here these unique datasets in order to investigate the peculiar and weak on-going solar cycle 24. As this cycle 24 is reaching its maximum, we compare its rising phase with the rising phase of the previous solar cycle 23.

  4. EDITORIAL: Selected papers from the 19th International Colloquium on Magnetic Films and Surfaces

    NASA Astrophysics Data System (ADS)

    Miyazaki, T.; Inoue, J.

    2007-03-01

    The 19th International Colloquium on Magnetic Films and Surfaces (ICMFS 2006) was held on 14-18 August 2006 at the Sendai International Center in Sendai, Japan. The purpose of the Colloquium was to bring together scientists working on magnetic thin films and surfaces and to provide an opportunity for presentation and discussion of recent experimental and theoretical advances in the field. 285 scientists from 17 countries (Japan: 167, overseas: 118) participated in the Colloquium, as well as 6 family members. There were 56 oral and 178 poster presentations. The oral presentations consisted of 3 plenary talks, 23 invited talks and 30 contributed talks. The number of presentations by scientific category are as follows: Spin dependent transport: 43 Magnetic storage/memory: 9 Magnetization reversal and fast dynamics: 15 Spin injection and spin transfer torque: 26 Magnetic thin films and multilayers: 71 High spin polarization materials: 17 Hard and soft magnetic materials: 3 Magneto-optics: 5 Characterization techniques for thin films and surfaces: 7 Exchange coupling: 13 Micro- and nanopatterned magnetic structures: 18 Micromagnetic modelling: 2 One of the characteristics of the present Colloquium is an increase in the number of presentations in the field of spin-electronics, as seen above. This Cluster Issue of Journal of Physics D: Applied Physics includes several important papers in this rapidly developing field. We believe that, in the future, the field of magnetic materials will maintain its popularity and, on top of that, other fields such as spintronics materials, materials related to life sciences and medicine and also materials related to the environment will be investigated further. The ICMFS Conference started in London in 1964, and is now one of the world-wide conferences on magnetism. The Colloquium has been held in Japan four times now: the previous ones being the 5th ICMFS in the Mount Fuji area, the 10th at Yokohama and the 17th at Kyoto, which was

  5. Dealing with Variability: Inter and Intra-annual Climate Variability and its Impacts on Water Availability in the 19th Century Northeastern United States

    NASA Astrophysics Data System (ADS)

    Aloysius, N. R.; Witherell, B. B.; Allen, T. L.; Arrigo, J. S.; Vorosmarty, C. J.

    2009-12-01

    Freshwater plays a critical role in preserving the biological and hydrological functions of the terrestrial ecosystems that sustain civilization. Hydrologic processes shape the distribution, structure, and dynamics of biological systems, while the feedbacks from biological systems impact the hydrologic cycle. Climate is the main driver that adds dynamics to the hydrologic cycle. In order to identify the changes and variability in the Northeast region’s climate and to understand their impacts on the hydrological cycle, we are conducting an assessment of the region’s climate. Annual and monthly time series of precipitation and temperature data collected for one hundred locations in the region, spanning from Maine to Virginia, during the period 1800 to 1920 are analyzed to assess the spatial and temporal variations in climate. It has been reported that the region’s climate during the 19th century is largely modulated by climatic oceanicity and the sunspot rhythm, and, that human influence did not have significant impact on the regional climate. Our preliminary findings do not show significant variations in the mean annual climate, but show variations in intra-annual climate, particularly monthly precipitation. Based on the review of historical documents, the intra-annual variation in precipitation was a concern of water resource planners during the 19th century. The present research attempts to bring out linkages between spatial and temporal variations in the regional climate and water availability. Additional information on land cover, measured and modeled runoff for a selected location will be used as case study to highlight climate variability and its impact on water availability.

  6. Probing the equinoctial hypothesis over recent solar cycles

    NASA Astrophysics Data System (ADS)

    Farrugia, C.; Miyoshi, Y.; Jordanova, V.

    2003-04-01

    According to Russell and McPherron (1973), stronger and more frequent storms are induced on a half-annual cadence due to the tilt of the Earth's dipole. We carry out a statistical investigation of this using 1-hour averaged Dst index values as a measure of the strength of geomagnetic storms over the period 1969-2001 (3 solar cycles), and energetic electron and proton fluxes measured BY NOAA/TIROS typical of the inner ring current and radiation belts, respectively for the last 2 cycles in the interval 1979-2001. We subdivide the data sets into ascending (sunpsot number > 50) and descending phases (< 50 ), and the storm strengths into two categories: peak hourly Dst < -60 nT, and hourly peak Dst < -100 nT. The variation equinox / solstice is evident in both Dst measurments and energetic particles fluxes. The number of storms falls off exponentially with storm strength both at equinox and solstice. There is practically no difference in the average storm strength at equinox/solstice. However, the storm frequency of both categories is larger at equinox. Exceptional cases like the Bastille day (July 2000) form a large-scale deviation from this pattern. The aim of this study is to understand the effects of the orientation of the Earth's dipole on geomagnetic strom dynamics and to reveal systematics which will be useful for the development of space weather predictions. C. T. Russell and R. L. MCPherron, JGR, 78, 92, 1973 Work supported in part by NASA GRANT NAG 5-10883.

  7. SOLAR CYCLE PROPAGATION, MEMORY, AND PREDICTION: INSIGHTS FROM A CENTURY OF MAGNETIC PROXIES

    SciTech Connect

    Munoz-Jaramillo, Andres; DeLuca, Edward E.; Dasi-Espuig, Maria; Balmaceda, Laura A. E-mail: edeluca@cfa.harvard.edu E-mail: lbalmaceda@icate-conicet.gob.ar

    2013-04-20

    The solar cycle and its associated magnetic activity are the main drivers behind changes in the interplanetary environment and Earth's upper atmosphere (commonly referred to as space weather). These changes have a direct impact on the lifetime of space-based assets and can create hazards to astronauts in space. In recent years there has been an effort to develop accurate solar cycle predictions (with aims at predicting the long-term evolution of space weather), leading to nearly a hundred widely spread predictions for the amplitude of solar cycle 24. A major contributor to the disagreement is the lack of direct long-term databases covering different components of the solar magnetic field (toroidal versus poloidal). Here, we use sunspot area and polar faculae measurements spanning a full century (as our toroidal and poloidal field proxies) to study solar cycle propagation, memory, and prediction. Our results substantiate predictions based on the polar magnetic fields, whereas we find sunspot area to be uncorrelated with cycle amplitude unless multiplied by area-weighted average tilt. This suggests that the joint assimilation of tilt and sunspot area is a better choice (with aims to cycle prediction) than sunspot area alone, and adds to the evidence in favor of active region emergence and decay as the main mechanism of poloidal field generation (i.e., the Babcock-Leighton mechanism). Finally, by looking at the correlation between our poloidal and toroidal proxies across multiple cycles, we find solar cycle memory to be limited to only one cycle.

  8. How to compare the faces of the Earth? Walachia in mid-19th century and nowadays

    NASA Astrophysics Data System (ADS)

    Bartos-Elekes, Zsombor; Magyari-Sáska, Zsolt; Timár, Gábor; Imecs, Zoltán

    2014-05-01

    In 1864 a detailed map was made about Walachia, its title is Charta României Meridionale (Map of Southern Romania), it has 112 map sheets, it is often called after his draughtsman: Szathmári's map. The map has an outstanding position in the history of Romanian cartography, because it indicates a turning-point. Before the map, foreigners (Austrians and Russians) had made topographic maps about this vassal principality of the Ottoman Empire. The Austrian topographic survey (1855-1859) - which served as a basis for this map - was the last one and the most detailed of these surveys. The map was made between the personal-union (1859) and independence (1878) of the Danubian Principalities. This map was the first (to a certain extent) own map of the forming country. In consequence of this survey and map, the Romanian mapping institute was founded, which one - based on this survey and map - began the topographic mapping of the country. In the Romanian scientific literature imperfect and contradictory information has been published about this map. Only a dozen copies of the map were kept in few map collections; the researchers could have reached them with difficulties. During our research we processed the circumstances of the survey and mapmaking discovering its documentation in the archives of Vienna, as well as using the Romanian, Hungarian and German scientific literature. We found the copies in map collections from Vienna to Bucharest. We digitized all the map sheets from different collections. We calculated the parameters of the used geodetic datum and map projection. We published on the web, such we made the map reachable for everybody. The map can be viewed in different zoom levels; can be downloaded; settlements can be found using the place name index; areas can be exported in modern projection, so the conditions of that time could be compared with today's reality. Our poster presents on the one hand the survey and the map realized in mid-19th century and our

  9. Hard X-Ray Emission from Partially Occulted Solar Flares: RHESSI Observations in Two Solar Cycles

    NASA Astrophysics Data System (ADS)

    Effenberger, Frederic; Rubio da Costa, Fatima; Oka, Mitsuo; Saint-Hilaire, Pascal; Liu, Wei; Petrosian, Vahé; Glesener, Lindsay; Krucker, Säm

    2017-02-01

    Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal looptop source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their acceleration site, without footpoint contamination. To this end, a statistical study of partially occulted flares observed with Reuven Ramaty High-Energy Solar Spectroscopic Imager is presented here, covering a large part of solar cycles 23 and 24. We perform detailed spectra, imaging, and light curve analyses for 116 flares and include contextual observations from SDO and STEREO when available, providing further insights into flare emission that were previously not accessible. We find that most spectra are fitted well with a thermal component plus a broken power-law, non-thermal component. A thin-target kappa distribution model gives satisfactory fits after the addition of a thermal component. X-ray imaging reveals small spatial separation between the thermal and non-thermal components, except for a few flares with a richer coronal source structure. A comprehensive light curve analysis shows a very good correlation between the derivative of the soft X-ray flux (from GOES) and the hard X-rays for a substantial number of flares, indicative of the Neupert effect. The results confirm that non-thermal particles are accelerated in the corona and estimated timescales support the validity of a thin-target scenario with similar magnitudes of thermal and non-thermal energy fluxes.

  10. GLE and the NON-GLE Solar Events Observed by AMS-02 in Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Bindi, V.; Consolandi, C.; Corti, C.; Whitman, K.

    2014-12-01

    The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle detector installed on the International Space Station (ISS) on May 2011 to study origin and nature of cosmic rays in the energy range from hundreds of MeV to a few TeV. In the first 3 years of operation, AMS-02 measured the highest part of the Solar Energetic Particle (SEP) spectra produced during M-and X-class flares and fast Coronal Mass Ejection. AMS-02 is able to perform precise measurements in a short period of time which is typical of these transient phenomena and to collected enough statistics to fully measure fine structures and time evolution of the spectrum. So far in Solar Cycle 24, one official Ground Level Enhancement (GLE) was observed on May 17, 2012 by Neutron Monitors (NM) while another possible GLE on January 6, 2014 was detected by South Pole NM. Observations by GOES-13, in the high energy proton channels, suggest that there were only 5 SEP events with energies above 500 MeV in this Cycle 24. AMS-02 observations, instead, indicate that since May 2011 there were more than 5 solar events with energies above 500 MeV at Earth. AMS-02 observations, with unprecedented resolution, large acceptance and high statistics, can therefore help the heliophysics community to better understand the true behavior of SEPs at high energies and to constrain models of SEP production. The SEP fluxes of GLE and NON-GLE events observed by AMS-02 will be presented.

  11. Solar-cycle variation of the rotational shear near the solar surface

    NASA Astrophysics Data System (ADS)

    Barekat, A.; Schou, J.; Gizon, L.

    2016-10-01

    Context. Helioseismology has revealed that the angular velocity of the Sun increases with depth in the outermost 35 Mm of the Sun. Recently, we have shown that the logarithmic radial gradient (dlnΩ/dlnr) in the upper 10 Mm is close to -1 from the equator to 60° latitude. Aims: We aim to measure the temporal variation of the rotational shear over solar cycle 23 and the rising phase of cycle 24 (1996-2015). Methods: We used f mode frequency splitting data spanning 1996 to 2011 from the Michelson Doppler Imager (MDI) and 2010 to 2015 from the Helioseismic Magnetic Imager (HMI). In a first for such studies, the f mode frequency splitting data were obtained from 360-day time series. We used the same method as in our previous work for measuring dlnΩ/dlnr from the equator to 80° latitude in the outer 13 Mm of the Sun. Then, we calculated the variation of the gradient at annual cadence relative to the average over 1996 to 2015. Results: We found the rotational shear at low latitudes (0° to 30°) to vary in-phase with the solar activity, varying by ~± 10% over the period 1996 to 2015. At high latitudes (60° to 80°), we found rotational shear to vary in anti-phase with the solar activity. By comparing the radial gradient obtained from the splittings of the 360-day and the corresponding 72-day time series of HMI and MDI data, we suggest that the splittings obtained from the 72-day HMI time series suffer from systematic errors. Conclusions: We provide a quantitative measurement of the temporal variation of the outer part of the near surface shear layer which may provide useful constraints on dynamo models and differential rotation theory.

  12. Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

    NASA Technical Reports Server (NTRS)

    Six, L. D.; Ashe, T. L.; Dobler, F. X.; Elkins, R. T.

    1980-01-01

    Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

  13. A new solar cycle model including meridional circulation

    NASA Technical Reports Server (NTRS)

    Wang, Y.-M.; Sheeley, N. R., Jr.; Nash, A. G.

    1991-01-01

    A kinematic model is presented for the solar cycle which includes not only the transport of magnetic flux by supergranular diffusion and a poleward bulk flow at the sun's surface, but also the effects of turbulent diffusion and an equatorward 'return flow' beneath the surface. As in the earlier models of Babcock and Leighton, the rotational shearing of a subsurface poloidal field generates toroidal flux that erupts at the surface in the form of bipolar magnetic regions. However, such eruptions do not result in any net loss of toroidal flux from the sun (as assumed by Babcock and Leighton); instead, the large-scale toroidal field is destroyed both by 'unwinding' as the local poloidal field reverses its polarity, and by diffusion as the toroidal flux is transported equatorward by the subsurface flow and merged with its opposite hemisphere counterpart. The inclusion of meridional circulation allows stable oscillations of the magnetic field, accompanied by the equatorward progression of flux eruptions, to be achieved even in the absence of a radial gradient in the angular velocity. An illustrative case in which a subsurface flow speed of order 1 m/s and subsurface diffusion rate of order 10 sq km/s yield 22-yr oscillations in qualitative agreement with observations.

  14. Solar cycle signal in Earth rotation: nonstationary behavior.

    PubMed

    Currie, R G

    1981-01-23

    Following the discovery of the 11-year solar cycle signal in earth rotation, linear techniques were employed to investigate the amplitude and phase of the difference between ephemeris time and universal time (DeltaT) as a function of time. The amplitude is nonstationary. This difference was related to Delta(LOD), the difference between the length of day and its nominal value. The 11-year term in Delta(LOD) was 0.8 millisecond at the close of the 18th century and decreased below noise level from 1840 to 1860. From 1875 to 1925, Delta(LOD) was about 0.16 millisecond, and it decreased to about 0.08 millisecond by the 1950's. Except for anomalous behavior from 1797 to 1838, DeltaT lags sunspot numbers by 3.0 +/- 0.4 years. Since DeltaT lags Delta(LOD) by 2.7 years, the result is that Delta(LOD) is approximately in phase with sunspot numbers.

  15. QBO as Potential Amplifier of Solar Cycle Influence

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mangel, John G.; Wolff, Charles L.; Porter, Hayden S.

    2006-01-01

    The solar cycle (SC) effect in the lower atmosphere has been linked observationally to the quasi-biennial oscillation (QBO) of the zonal circulation. Salby and Callaghan (2000) in particular analyzed the QBO covering more than 40 years and found that it contains a large SC signature at 20 km. We discuss a 3D study in which we simulate the QBO under the influence of the SC. For a SC period of 10 years, the relative amplitude of radiative forcing is taken to vary with height: 0.2% (surface), 2% (50 km), 20% (100 km and above). This model produces in the lower stratosphere a relatively large modulation of the QBO, which appears to come from the SC and qualitatively agrees with the observations. The modulation of the QBO, with constant phase relative to the SC, is shown to persist at least for 50 years, and it is induced by a SC modulated annual oscillation that is hemispherically symmetric and confined to low latitudes.

  16. Temporal Offsets Between Maximum CME Speed Index and Solar, Geomagnetic, and Interplanetary Indicators During Solar Cycle 23 and the Ascending Phase of Cycle 24

    NASA Astrophysics Data System (ADS)

    Özgüç, A.; Kilcik, A.; Georgieva, K.; Kirov, B.

    2016-05-01

    On the basis of a morphological analysis of yearly values of the maximum coronal mass ejection (CME) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and interplanetary magnetic field strength, and the geomagnetic Ap and D_{st} indices, we point out the particularities of solar and geomagnetic activity during the last Cycle 23, the long minimum that followed it, and the ascending branch of Cycle 24. We also analyze the temporal offset between the maximum CME speed index and the above-mentioned solar, geomagnetic, and interplanetary indices. It is found that this solar activity index, analyzed jointly with other solar activity, interplanetary parameters, and geomagnetic activity indices, shows a hysteresis phenomenon. It is observed that these parameters follow different paths for the ascending and descending phases of Cycle 23. The hysteresis phenomenon represents a clue in the search for physical processes responsible for linking the solar activity to near-Earth and geomagnetic responses.

  17. Breathing of heliospheric structures triggered by the solar-cycle activity

    NASA Astrophysics Data System (ADS)

    Scherer, K.; Fahr, H. J.

    2003-06-01

    Solar wind ram pressure variations occuring within the solar activity cycle are communicated to the outer heliosphere as complicated time-variabilities, but repeating its typical form with the activity period of about 11 years. At outer heliospheric regions, the main surviving solar cycle feature is a periodic variation of the solar wind dynamical pressure or momentum flow, as clearly recognized by observations of the VOYAGER-1/2 space probes. This long-periodic variation of the solar wind dynamical pressure is modeled here through application of appropriately time-dependent inner boundary conditions within our multifluid code to describe the solar wind - interstellar medium interaction. As we can show, it takes several solar cycles until the heliospheric structures adapt to an average location about which they carry out a periodic breathing, however, lagged in phase with respect to the solar cycle. The dynamically active heliosphere behaves differently from a static heliosphere and especially shows a historic hysteresis in the sense that the shock structures move out to larger distances than explained by the average ram pressure. Obviously, additional energies are pumped into the heliosheath by means of density and pressure waves which are excited. These waves travel outwards through the interface from the termination shock towards the bow shock. Depending on longitude, the heliospheric sheath region memorizes 2-3 (upwind) and up to 6-7 (downwind) preceding solar activity cycles, i.e. the cycle-induced waves need corresponding travel times for the passage over the heliosheath. Within our multifluid code we also adequately describe the solar cycle variations in the energy distributions of anomalous and galactic cosmic rays, respectively. According to these results the distribution of these high energetic species cannot be correctly described on the basis of the actually prevailing solar wind conditions.

  18. Influence of the solar UV-radiation intensity on the 630-nm nightglow emission in the 23rd solar cycle

    NASA Astrophysics Data System (ADS)

    Ievenko, I. B.; Alekseev, V. N.; Parnikov, S. G.

    2011-10-01

    It is well known that the 630-nm nightglow emission intensity in midlatitudes increases by more than a factor of 2 during a sunspot maximum. It has been assumed that the phenomenon is caused by variations in solar UV radiation during a solar cycle (Fishkova, 1983). We present the results of photometric measurements of the nightglow 630.0 nm emission intensity at a latitude of 63° E and longitude of 130° E (Yakutsk) in 1990-2007. The dependence of the 630-nm emission intensity on solar activity on magnetically quiet days in the 22nd and 23rd solar cycles is shown. The close relationship between the 630-nm nightglow intensity and the intensity of extreme UV (EUV) with a correlation coefficient of 0.8-0.9 in 1997-2007 is ascertained from the SOHO/SEM data. The dominance of solar EUV in the excitation of nightglow 630-nm emission has thus been experimentally proved.

  19. [Epidemic diseases in the Polish Kingdom in the thirties of the 19th century].

    PubMed

    Rutkowski, Marek

    2004-01-01

    We can observe that after downfall of the November Insurrection the authorities of the Polish Kingdom were effectively engaged in the fight against numerous epidemic diseases plaguing the local society. Among "contagions" of the time there were varicella, "gastric-nervous fever", "gastric-rhinitis fever" and typhus (especially in 1836). As usual, cholera was the most dangerous one. All medical and epidemiological services in the Polish Kingdom were making effective remedial measures in order to neutralize results of the epidemics. The implemented methods were effective enough to limit considerably the incidence and number of deceased during the epidemic, which started in October 1836 and lasted till the next year. An obligation of effective cooperation between the Polish authorities and the Russian army was introduced then. The sanitary action against cholera in 1836-1837 should be very highly assessed from the logistic point of view. The wide action of protective vaccination against varicella and numerous sanitary rules completed the favorable image of the Polish Kingdom sanitary services. All the factors mentioned above lead to a conclusion that in the thirtieth of the 19th century both civil and military authorities of the Polish Kingdom did practically utmost in order to limit negative results of cyclical recurrences of epidemic diseases. It should be also stressed that the protective actions undertaken in that time were both direct and long lasting enterprises.

  20. The impact of childhood sickness on adult socioeconomic outcomes: Evidence from late 19th century America

    PubMed Central

    Warren, John Robert; Knies, Laurie; Haas, Steven; Hernandez, Elaine M.

    2013-01-01

    We use family fixed-effects models to estimate the impact of childhood health on adult literacy, labor force outcomes, and marital status among pairs of white brothers observed as children in the 1880 U.S. Census and then as adults in the 1900–1930 Censuses. Given our focus on the 19th century, we observed a wider array of infectious, chronic, and traumatic health problems than is observed using data that are more recent; our results thus provide some insights into circumstances in modern developing countries where similar health problems are more frequently observed. Compared to their healthy siblings, sick brothers were less likely to be located (and thus more likely to be dead) 20–50 years after their 1880 enumeration. Sick brothers were also less likely to be literate, to have ever been married, and to have reported an occupation. However, among those with occupations, sick and healthy brothers tended to do similar kinds of work. We discuss the implications of our results for research on the impact of childhood health on socioeconomic outcomes in developed and developing countries. PMID:22809795

  1. Naming and Necessity: Sherborn’s Context in the 19th Century

    PubMed Central

    McOuat, Gordon

    2016-01-01

    Abstract By the late 19th Century, storms plaguing early Victorian systematics and nomenclature seemed to have abated. Vociferous disputes over radical renaming, the world-shaking clash of all-encompassing procrustean systems, struggles over centres of authority, and the issues of language and meaning had now been settled by the institution of a stable imperial museum and its catalogues, a set of rules for the naming of zoological objects, and a new professional class of zoologists. Yet, for all that tranquillity, the disputes simmered below the surface, re-emerging as bitter struggles over synonyms, trinomials, the subspecies category, the looming issues of the philosophy of scientific language, and the aggressive new American style of field biology – all pressed in upon the received practice of naming and classifying organisms and the threat of anarchy. In the midst rose an index. This paper will explore the context of CD Sherborn’s Index Animalium and those looming problems and issues which a laborious and comprehensive “index of nature” was meant to solve. PMID:26877652

  2. Factors influencing the recession rate of Niagara Falls since the 19th century

    NASA Astrophysics Data System (ADS)

    Hayakawa, Yuichi S.; Matsukura, Yukinori

    2009-09-01

    The rate of recession of Niagara Falls (Horseshoe and American Falls) in northeastern North America has been documented since the 19th century; it shows a decreasing trend from ca. 1 m y - 1 a century ago to ca. 0.1 m y - 1 at present. Reduction of the flow volume in the Niagara River due to diversion into bypassing hydroelectric schemes has often been taken to be the factor responsible, but other factors such as changes in the waterfall shape could play a role and call for a quantitative study. Here, we examine the effect of physical factors on the historically varying recession rates of Niagara Falls, using an empirical equation which has previously been proposed based on a non-dimensional multiparametric model which incorporates flow volume, waterfall shape and bedrock strength. The changes in recession rates of Niagara Falls in the last century are successfully modeled by this empirical equation; these changes are caused by variations in flow volume and lip length. This result supports the validity of the empirical equation for waterfalls in rivers carrying little transported sediment. Our analysis also suggests that the decrease in the recession rate of Horseshoe Falls is related to both artificial reduction in river discharge and natural increase in waterfall lip length, whereas that of American Falls is solely due to the reduction in flow volume.

  3. Collateral damage to marine and terrestrial ecosystems from Yankee whaling in the 19th century.

    PubMed

    Drew, Joshua; López, Elora H; Gill, Lucy; McKeon, Mallory; Miller, Nathan; Steinberg, Madeline; Shen, Christa; McClenachan, Loren

    2016-11-01

    Yankee whalers of the 19th century had major impacts on populations of large whales, but these leviathans were not the only taxa targeted. Here, we describe the "collateral damage," the opportunistic or targeted taking of nongreat whale species by the American whaling industry. Using data from 5,064 records from 79 whaling logs occurring between 1840 and 1901, we show that Yankee whalers captured 5,255 animals across three large ocean basins from 32 different taxonomic categories, including a wide range of marine and terrestrial species. The taxa with the greatest number of individuals captured were walruses (Odobenus rosmarus), ducks (family Anatidae), and cod (Gadus sp.). By biomass, the most captured species were walruses, grampus (a poorly defined group within Odontoceti), and seals (family Otariidae). The whalers captured over 2.4 million kg of nongreat whale meat equaling approximately 34 kg of meat per ship per day at sea. The species and areas targeted shifted over time in response to overexploitation of whale populations, with likely intensive local impacts on terrestrial species associated with multiyear whaling camps. Our results show that the ecosystem impacts of whaling reverberated on both marine and coastal environments.

  4. F/A-18 1/9th scale model tail buffet measurements

    NASA Technical Reports Server (NTRS)

    Martin, C. A.; Glaister, M. K.; Maclaren, L. D.; Meyn, L. A.; Ross, J.

    1991-01-01

    Wind tunnel tests were carried out on a 1/9th scale model of the F/A-18 at high angles of attack to investigate the characteristics of tail buffet due to bursting of the wing leading edge extension (LEX) vortices. The tests were carried out at the Aeronautical Research Laboratory low-speed wind tunnel facility and form part of a collaborative activity with NASA Ames Research Center, organized by The Technical Cooperative Program (TTCP). Information from the program will be used in the planning of similar collaborative tests, to be carried out at NASA Ames, on a full-scale aircraft. The program covered the measurement of unsteady pressures and fin vibration for cases with and without the wing LEX fences fitted. Fourier transform methods were used to analyze the unsteady data, and information on the spatial and temporal content of the vortex burst pressure field was obtained. Flow visualization of the vortex behavior was carried out using smoke and a laser light sheet technique.

  5. [Contribution of 19th-century religious congregations in the development of the nursing profession].

    PubMed

    Bezze, Sabrina; Manzoni, Edoardo; Di Mauro, Stefania

    2013-01-01

    The purpose of this historical research project is to examine the contribution of 19th-century religious congregations in the development of the nursing profession, based on the historical example of the Sisters of Charity of Sts. Bartolomea Capitanio and Vincenza Gerosa (or the Sisters of the Holy Child Mary). To this end, sixty three volumes were analysed, all taken from the historical archive of the Generalate of the Sisters of the Holy Child Mary in Milan, in via S. Sofia n.13, with the exception of just one, taken from the Braidense National Library, also in Milan. This research project has highlighted the sociological contribution provided by the Sisters of the Holy Child Mary to the professional nature of nursing, and to the development of the distinctive features of the nursing profession (Greenwood, 1980). All documentary sources were analysed in line with the Chabod historical research method (2006), and for their critical interpretation, a scheme of analysis was created. Two lines of investigation emerged from the data collected: the role of Sister Emilia Vinante as an expert with regard to the nursing profession, and the professional strategies promoted by FIRO (Federation of Italian Religious Nurses). Based on the conclusions of the research project, it may be stated that religious congregations contributed greatly to the nursing profession, leaving a decisive mark on the cultural and professional development of nurses.

  6. Climate and history in the late 18th and early 19th centuries

    NASA Astrophysics Data System (ADS)

    Feldman, Theodore S.

    As in many areas of human knowledge, the notion of climate acquired a deeper historical content around the turn of the 19th century. Natural philosophers, geographers, and others became increasingly aware of climate's own history and its relation to human, plant and animal, and Earth history. This article examines several aspects of this “historicization” of climate.The lively 18th century discussion of the influence of climate on society is well known. Montesquieu is its most famous representative, but Voltaire, Hume, Kant, and others also participated. Their debate was literary more than scientific, their goal the understanding of man, not climate. Partly for this reason and partly because of the lack of good information on climates, they made no attempt to gather substantial climatic data. In fact, the importance of systematically collecting reliable data was scarcely understood in any area of natural philosophy before the last decades of the century [Cf. Frängsmyr et al., 1990; Feldman, 1990]. Instead, participants in the debate repeated commonplaces dating from Aristotle and Hippocrates and based their conclusions on unreliable reports from travelers. As Glacken wrote of Montesquieu, “his dishes are from old and well-tested recipes” [Glacken, 1967, chapter 12]. This is not to say that the debate over climatic influence was not significant—only that its significance lay more in the history of man than in the atmospheric sciences.

  7. Shark tooth weapons from the 19th Century reflect shifting baselines in Central Pacific predator assemblies.

    PubMed

    Drew, Joshua; Philipp, Christopher; Westneat, Mark W

    2013-01-01

    The reefs surrounding the Gilbert Islands (Republic of Kiribati, Central Pacific), like many throughout the world, have undergone a period of rapid and intensive environmental perturbation over the past 100 years. A byproduct of this perturbation has been a reduction of the number of shark species present in their waters, even though sharks play an important in the economy and culture of the Gilbertese. Here we examine how shark communities changed over time periods that predate the written record in order to understand the magnitude of ecosystem changes in the Central Pacific. Using a novel data source, the shark tooth weapons of the Gilbertese Islanders housed in natural history museums, we show that two species of shark, the Spot-tail (Carcharhinus sorrah) and the Dusky (C. obscurus), were present in the islands during the last half of the 19(th) century but not reported in any historical literature or contemporary ichthyological surveys of the region. Given the importance of these species to the ecology of the Gilbert Island reefs and to the culture of the Gilbertese people, documenting these shifts in baseline fauna represents an important step toward restoring the vivid splendor of both ecological and cultural diversity.

  8. Age-specific measles mortality during the late 19th-early 20th centuries.

    PubMed

    Shanks, G D; Waller, M; Briem, H; Gottfredsson, M

    2015-12-01

    Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14-15% of measles deaths as opposed to 8-9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

  9. Neurologic approaches to hysteria, psychogenic and functional disorders from the late 19th century onwards.

    PubMed

    Stone, J

    2017-01-01

    The history of functional neurologic disorders in the 20th century from the point of view of the neurologist is U-shaped. A flurry of interest between the 1880s and early 1920s gave way to lack of interest, skepticism, and concern about misdiagnosis. This was mirrored by increasing professional and geographic divisions between neurology and psychiatry after the First World War. In the 1990s the advent of imaging and other technology highlighted the positive nature of a functional diagnosis. Having been closer in the early 20th century but later more separate, these disorders are now once again the subject of academic and clinical interest, although arguably still very much on the fringes of neurology and neuropsychiatry. Revisiting older material provides a rich source of ideas and data for today's clinical researcher, but also offers cautionary tales of theories and treatments that led to stagnation rather than advancement of the field. Patterns of treatment do have a habit of repeating themselves, for example, the current enthusiasm for transcranial magnetic stimulation compared to the excitement about electrotherapy in the 19th century. For these reasons, an understanding of the history of functional disorders in neurology is arguably more important than it is for other areas of neurologic practice.

  10. The dawn of chelonian research: turtles between comparative anatomy and embryology in the 19th century.

    PubMed

    MacCord, Kate; Caniglia, Guido; Moustakas-Verho, Jacqueline E; Burke, Ann C

    2015-05-01

    Many evo-devo studies of the turtle's shell draw hypotheses and support from historical sources. The groundbreaking works of Cuvier, Geoffroy St. Hilaire, Carus, Rathke, Owen, and others are being revived in modern research, and their centuries-old understanding of the turtle's shell reconsidered. In the works of these eminent biologists of the 19th century, comparative anatomy and embryology of turtle morphology set the stage for future studies in developmental biology, histology, and paleontology. Given the impact that these works still make on modern research, it is important to develop a thorough appreciation of previous authors, regarding how they arrived at their conclusions (i.e., what counted as evidence?), whether there was debate amongst these authors about shell development (i.e., what counted as an adequate explanation?), and even why these men, some of the most powerful and influential thinkers and anatomists of their day, were concerned with turtles. By tracing and exposing the context and content of turtle shell studies in history, our aim is to inform modern debates about the evolution and development of the turtle's shell.

  11. Supercritical CO2 Power Cycles: Design Considerations for Concentrating Solar Power

    SciTech Connect

    Neises, Ty; Turchi, Craig

    2014-09-01

    A comparison of three supercritical CO2 Brayton cycles: the simple cycle, recompression cycle and partial-cooling cycle indicates the partial-cooling cycle is favored for use in concentrating solar power (CSP) systems. Although it displays slightly lower cycle efficiency versus the recompression cycle, the partial-cooling cycle is estimated to have lower total recuperator size, as well as a lower maximum s-CO2 temperature in the high-temperature recuperator. Both of these effects reduce recuperator cost. Furthermore, the partial-cooling cycle provides a larger temperature differential across the turbine, which translates into a smaller, more cost-effective thermal energy storage system. The temperature drop across the turbine (and by extension, across a thermal storage system) for the partial-cooling cycle is estimated to be 23% to 35% larger compared to the recompression cycle of equal recuperator conductance between 5 and 15 MW/K. This reduces the size and cost of the thermal storage system. Simulations by NREL and Abengoa Solar indicate the partial-cooling cycle results in a lower LCOE compared with the recompression cycle, despite the former's slightly lower cycle efficiency. Advantages of the recompression cycle include higher thermal efficiency and potential for a smaller precooler. The overall impact favors the use of a partial-cooling cycle for CSP compared to the more commonly analyzed recompression cycle.

  12. Flexible thermal cycle test equipment for concentrator solar cells

    DOEpatents

    Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  13. Evolution of the Interplanetary Magnetic Field sector structure during the last 15 solar cycles

    NASA Astrophysics Data System (ADS)

    Vokhmyanin, Mikhail

    We have inferred for the first time Interplanetary Magnetic Field (IMF) polarities from ground-based geomagnetic observations back to 1844. Reconstructions are reliable enough to study sector structure of the IMF in the past. The inferred daily polarities demonstrate solar-cycle changes during the nineteenth and twentieth centuries. We have analyzed statistics of the sector boundaries and found recurrences that reflect evolution of the solar wind sources. Additionally, seasonal variations of the ratio of positive and negative sectors provide evidence of solar magnetic field reversals during the last 15 solar cycles.

  14. Effects of Space Weather on Biomedical Parameters during the Solar Activity Cycles 23-24.

    PubMed

    Ragul'skaya, M V; Rudenchik, E A; Chibisov, S M; Gromozova, E N

    2015-06-01

    The results of long-term (1998-2012) biomedical monitoring of the biotropic effects of space weather are discussed. A drastic change in statistical distribution parameters in the middle of 2005 was revealed that did not conform to usual sinusoidal distribution of the biomedical data reflecting changes in the number of solar spots over a solar activity cycle. The dynamics of space weather of 2001-2012 is analyzed. The authors hypothesize that the actual change in statistical distributions corresponds to the adaptation reaction of the biosphere to nonstandard geophysical characteristics of the 24th solar activity cycle and the probable long-term decrease in solar activity up to 2067.

  15. A comparative study of solar facula during cycle 23 and 24

    NASA Astrophysics Data System (ADS)

    Chowdhury, P.; Choudhary, D. P.; Moon, Y. J.

    2015-12-01

    The solar activity minimum between the end of cycle 23 and beginning of cycle 24 was the longest and deepest since the modern satellite era of 20th century. In this paper, we have investigated statistical properties of solar facula and sunspot area (and their ratio) covering entire solar cycle 23 and the ascending phase of cycle 24. The facular area has been considered from the K-line composite at the San Fernando Observatory and is a direct measurement of the strength of solar cycle activity. It is found that solar facular area decreased during minimum phase of cycle 23/24 compared to maximum phase and also during rising phase of cycle 24. However, the ratio of facula to sunspot area increased during minimum epoch of cycle 23. Power spectrum analysis shows that along with other periods, the solar rotational periods 22 -31 days and Rieger type periods are both prominent during maxima, minima of cycle 23 and ascending branch of cycle 24. During the decline phase of cycle 23, the period ~ 27 days is more prominent whereas ~ 14 days and ~ 31 days periods are dominant during activity maxima. During maximum phase of cycle 23 and 24, there was no phase lag between sunspot and facular area, but a phase lag ~ 3 months has been detected during activity minima of cycle 23. These results indicate that the distribution of active regions during the activity maximum years is quite different from that in the minimum years. We shall present discussion of our results in this paper.

  16. Threads of Change in 19th Century American Literature: A Language Arts Unit for Grades 7-9.

    ERIC Educational Resources Information Center

    Crossett, Becky F.; And Others

    This unit of study for junior-high level high-ability language arts students explores five themes in 19th century American history through literature of the times: romanticism, transcendentalism, abolitionism, industrialism, and feminism. Each of the five "isms" has its own "literature box" that contains appropriate documents…

  17. ​​​History of Cholera Outbreaks in Iran during the 19th and 20th Centuries

    PubMed Central

    Azizi, MH; Azizi, F

    2010-01-01

    Cholera is an acute infectious disease with high mortality if left untreated. Historically, between the 19th and 20th centuries seven great pandemics of cholera occurred and worldwide, thousands of people died. Based on an old theory, cholera was considered an air-born disease and the emergence of its outbreaks were attributed to bad weather or miasma. However later in the 18th century, British physician John Snow (1813-1858) explained the association of a terrible cholera outbreak in London in 1849 to contamination of the drinking water supply with human excreta. Despite his finding, the causative agent of this dreaded illness was unidentified until later in the 19th century. In 1854, Filippo Pacini (1812-1883) an anatomist from Italy and then in 1883, Robert Koch (1843-1910) the German bacteriologist, discovered ‘vibrio cholerae’ as the etiologic agent. During the major pandemics of cholera in 19th and 20th centuries this illness reached Iran and led to vast depopulation and a crucial impact on the country’s socioeconomic status. Poor public health conditions, lack of a well-organized public health authority for implementing preventive and quarantine measures as well as Iran’s specific geographic location were the main facilitating factors of the emergence of various epidemics, including cholera in Iran. The present paper briefly reviews the cholera outbreaks in Iran during the 19th and 20th centuries. PMID:25197514

  18. How To Dance through Time. Volume I: The Romance of Mid-19th Century Couple Dances. Beginning Level. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 35-minute VHS videotape is the first in a series of "How To Dance Through Time" videos. It provides how-to instructions to help beginning dancers learn the mid-19th century ballroom couple dances. It introduces dancers to the basic steps, which accompany the romantic dance music of the past. Each dance segment is introduced by a…

  19. The use of Congreve-type war Rockets by the Spanish in the 19th century: A chronology

    NASA Technical Reports Server (NTRS)

    Sancho, P. M.

    1977-01-01

    A yearly account of military uses, by the Spanish, of Congreve war rockets is given, from the year 1810 until 1895. Events prior to the 19th century are also recorded which include the use of rockets against the Moors of Valencia and documentation, from literature of that period, relating to rocket applications.

  20. The Case for Consolidation: Our 19th-Century Model of Governance Is a Formula for Mediocrity

    ERIC Educational Resources Information Center

    Amdursky, Saul

    2004-01-01

    We need fewer public libraries with greater dependence. Here at the beginning of the 21st century, public libraries are still saddled with a 19th-century model of government. They are far too beholden to governing authorities, usually municipal or county governments, for their financial sustenance. This is a formula for mediocrity. "Local control"…

  1. Founding of Compulsory Civil Education According to the Education Acts from Second Half of the 19th Century

    ERIC Educational Resources Information Center

    Lukaš, Mirko

    2012-01-01

    Records of education in Croatia occur very soon after the settlement of Croats in this area. It is tied to 9th century and Duke Trpimir. Initial steps of education were not legally bounded nor the school was obligatory. In the second half of the 19th century, more precisely in 1871, with the First Education Act education becomes obligatory. Using…

  2. How Conceptual Frameworks Influence Clinical Practice: Evidence from the Writings of John Thelwall, a 19th-Century Speech Therapist

    ERIC Educational Resources Information Center

    Duchan, Judith F.

    2006-01-01

    Background: The impact of speech therapists' conceptual frameworks on their clinical methods tends to be ignored or taken for granted by today's practitioners. One way to show the importance of such frameworks is to study how they were used previously. John Thelwall, a 19th-century elocutionist, offers a rich source for studying the influence of…

  3. The Struggle To Survive: Work for Racial Ethnic Women in the 18th- and 19th-Century United States.

    ERIC Educational Resources Information Center

    Higginbotham, Elizabeth

    The work situations of Black, Mexican American, and Chinese immigrant women in 18th- and 19th-century United States are explored. Generally, when engaged in agricultural work, all ethnic people were considered units of labor. However, because the slave owner needed to perpetuate his property, Black women were allowed lower rates of production when…

  4. The Divergence of CME and Sunspot Number Rates During Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Webb, David F.; St. Cyr, Orville Chris; Xie, Hong; Kuchar, Thomas Andrew

    2014-06-01

    In the previous three solar cycles the frequency of occurrence of CMEs observed in white light has closely tracked the solar cycle in both phase and amplitude, varying by an order of magnitude over the cycle. LASCO has now observed the entire solar Cycle 23 and continues to observe through the current rise and maximum phases of Cycle 24. Cycle 23 had an unusually long decline and extended minimum. During this period we have been able to image and count CMEs in the heliosphere, and can determine rates from both LASCO and STEREO SECCHI (since 2007) coronagraphs and from the Solar Mass Ejection Imager (SMEI - since 2003) and the SECCHI Heliospheric Imagers in the heliosphere. Manual rates estimated by observers are now supplemented by counts from identifications made by automatic programs, such as contained in the SEEDS, CACTus and ARTEMIS catalogs. Since the cycle 23/24 minimum, the CME and sunspot number rates have diverged, with similar cycle 23/24 rise and peak CME rates but much lower SSN rates in this cycle. We will discuss these rate estimates and their implications for the evolution of the global solar magnetic field.

  5. Solar cycle variations in ion composition in the dayside ionosphere of Titan

    NASA Astrophysics Data System (ADS)

    Madanian, H.; Cravens, T. E.; Richard, M. S.; Waite, J. H.; Edberg, N. J. T.; Westlake, J. H.; Wahlund, J.-E.

    2016-08-01

    One Titanian year spans over two complete solar cycles, and the solar irradiance has a significant effect on ionospheric densities. Solar cycle 24 has been one of the quietest cycles on record. In this paper we show data from the Cassini ion and neutral mass spectrometer (INMS) and the radio and plasma wave science Langmuir probe spanning the time period from early 2005, at the declining phase of solar cycle 23, to late 2015 at the declining phase of solar cycle 24. Densities of different ion species measured by the INMS show a consistent enhancement for high solar activity, particularly near the ionospheric peak. The density enhancement is best seen in primary ion species such as CH3+ rather than heavier ion species such as HCNH+. Unlike at Earth, where the ionosphere and atmosphere thermally expand at high solar activity, at Titan the altitude of the ionospheric peak decreases, indicating that the underlying neutral atmosphere was less extensive. Among the major ion species, CH5+ shows the largest decrease in peak altitude, whereas heavy ions such as C3H5+ show very little decrease. We also calculate the ion production rates using a theoretical model and a simple empirical model using INMS data and show that these effectively predict the increased ion production rates at high solar activity.

  6. Using Polar Coronal Hole Area Measurements to Determine the Solar Polar Magnetic Field Reversal in Solar Cycle 24

    NASA Technical Reports Server (NTRS)

    Karna, N.; Webber, S.A. Hess; Pesnell, W.D.

    2014-01-01

    An analysis of solar polar coronal hole (PCH) areas since the launch of the Solar Dynamics Observatory (SDO) shows how the polar regions have evolved during Solar Cycle 24. We present PCH areas from mid-2010 through 2013 using data from the Atmospheric Imager Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) instruments onboard SDO. Our analysis shows that both the northern and southern PCH areas have decreased significantly in size since 2010. Linear fits to the areas derived from the magnetic-field properties indicate that, although the northern hemisphere went through polar-field reversal and reached solar-maximum conditions in mid-2012, the southern hemisphere had not reached solar-maximum conditions in the polar regions by the end of 2013. Our results show that solar-maximum conditions in each hemisphere, as measured by the area of the polar coronal holes and polar magnetic field, will be offset in time.

  7. Solar cycle variation of interplanetary disturbances observed as Doppler scintillation transients

    NASA Technical Reports Server (NTRS)

    Woo, Richard

    1993-01-01

    Interplanetary disturbances characterized by plasma that is more turbulence and/or moves faster than the background solar wind are readily defected as transients in Doppler scintillation measurements of the near-Sun solar wind. Systematic analysis of over 23,000 hours of Pioneer Venus Orbiter Doppler measurements obtained inside 0.5 AU during 1979-1987 have made it possible for the first time to investigate the frequency of occurrence of Doppler scintillation transients under solar minimum conditions and to determine its dependence on solar cycle. On the basis of a total of 142 transients, Doppler scintillation transient rates vary from a high of 0.22 in 1979 (one every 4.6 days) to a low of 0.077 transients/d in 1986 (one every 13 days), a decrease by almost a factor of 3 from solar maximum to solar minimum. This solar cycle variation, the strongest yet of any solar wind Doppler scintillation property, is highly correlated with both solar activity characterized by sunspot number and the coronal mass ejection rates deduced from Solswind and Solar Maximum Mission (SMM) coronagraph observations. These results indicate that coronal mass ejections and Doppler scintillation transients are closely related not just during solar maximum, as occasional individual comparisons have shown in the past, but throughout the entire solar cycle, and strengthen the notation that the Doppler scintillation and optical transients are different manifestations of the same physical phenomenon. The magnitudes of the transients, as described by the ratio of peak to pretransient scintillation levels (EF for enhancement factor), and their distribution iwth heliocentric distance also vary with solar cycle. While EF tends to diminish with increasing heliocentric distance during high solar activity, it is more evenly distributed during low solar activity. EF is also lower during solar minimum, as 13% of the transients during solar maximum have values exceeding 23, the highest EF observed during

  8. Periodicities of hard x-ray burst during the last solar cycle

    NASA Technical Reports Server (NTRS)

    Hady, Ahmed A.

    1995-01-01

    By using power spectrum and standard FFT time series analysis, the Hard X-ray burst during solar cycle -22 were studied. This data of Hard X-ray burst spectrometer (HXRBS) on the solar maximum mission from Launch and February 14, 1980, through re-entry on December 2, 1989, by NASA artificial satellite. The results indicate that there are short and intermediate solar periodicities. Also it is found that there is a relation between the short periodicities (few minutes) with similar periodicities in solar radio emissions and in good agreement with the theoretical mode of solar oscillations.

  9. An extension of the VIRA electron temperature and density models to include solar cycle variations

    NASA Astrophysics Data System (ADS)

    Brace, L. H.; Theis, R. F.

    The original VIRA ionosphere model was based primarily on the Pioneer Venus Orbiter (PVO) data obtained at solar maximum (F10.7~200) in 1979 and 1980 when periapsis was being maintained deep in the Venusian ionosphere. In situ measurements provided data on temperature, composition, density, and drift velocity, while the radio occultation method provided height profiles of electron density, N_e. The solar cycle variation was deduced by comparison with the Venera 9 and 10 occultation data from the previous solar minimum. No data were available on the solar cycle variations of other ionospheric parameters, because periapsis had already risen out of the ionosphere by the time solar activity began to decline early in 1983. During the Entry period in the Fall of 1992, however, PVO got a brief glimpse of the nightside ionosphere at lower solar activity (F10.7~120). During the intervening decade important in situ data were obtained on the upper nightside ionosphere that extends far down stream from the planet. This region was found to be highly sensitive to solar wind interactions and solar activity. In this paper, we discuss ways in which the later PVO data can be used to extend the VIRA model to higher altitudes and to include the solar cycle variations. As an example, we present some pre-entry Orbiter Electron Temperature Probe measurements that provide new clues as to the dayside T_e behavior at low solar activity.

  10. An analysis of solar-cycle temporal relationships among activity indicators

    NASA Astrophysics Data System (ADS)

    Bachmann, K. T.; Maymani, H.; Nautiyal, K.; te Velde, V.

    2004-01-01

    Differences in the time development of solar activity indices are an important clue in the search for physical processes responsible for changing solar emission at various wavelengths. In this paper we describe our investigation of temporal relationships among two space-based indices, Lyman-α 121.6 nm emission (Lα) and the Mg II 280 nm core-to-wing ratio, and four ground-based indices - the 10.7 cm flux (F10), the He I 1083 nm equivalent width, the Ca II K 393.4 nm emission index, and the International Sunspot Number (ISN). We provide scatterplots of index pairs passed through a 2-year Gaussian filter during each available solar cycle, and we approximate the temporal relationships quantitatively as overall temporal offsets with uncertainties. We reconcile our findings with qualitative ideas concerning the variation of solar emissions with solar activity. Since the F10 and ISN time series are longer than four complete solar cycles, we are able to evaluate the reproducibility of temporal offsets over multiple solar cycles. The chief motivation for our work is to improve solar indicator analysis by providing a method of seeing and analyzing temporal relationships clearly and easily. We believe that future physical models of magnetic activity and spectral emissions in the solar chromosphere and transition region may make quantitative predictions of temporal relationships among full-disk solar indices for comparison with analyses such as ours.

  11. 3D Solar Wind Structure Features Characterizing the Rise of Cycle 24

    NASA Astrophysics Data System (ADS)

    Luhmann, J. G.; Ellenburg, M. A.; Riley, P.; Lee, C. O.; Arge, C. N.; Jian, L.; Russell, C. T.; Simunac, K.; Galvin, A. B.; Petrie, G. J.

    2011-12-01

    Since the launch of the STEREO mission in 2006, there has been renewed interest in the 3D structure of the solar wind, spurred in part by the unusual cycle 23 solar minimum and current solar cycle rise. Of particular significance for this subject has been the ubiquitous occurrence of low latitude coronal holes and coronal pseudo-streamers. These coupled features have been common both because of the relative strength of high order spherical harmonic content of the global coronal field, and the weakness of the field compared to the previous two well-observed cycles. We consider the effects of the low latitude coronal holes and pseudo-streamers on the near-ecliptic solar wind and interplanetary field. In particular, we illustrate how the now common passage of streams with low latitude sources and pseudo-streamer boundaries is changing our traditional perceptions of local solar wind structures.

  12. [Eventful life stories. Members of student fraternities persecuted in Silesia in the early 19th century].

    PubMed

    Schmidt, Walter

    2003-01-01

    This study supplemented by three charts and a list of biographies, is, for the first time, encompassing their life-data, their resumés and even their professional careers as well as political commitments shown by more than 200 Silesian students. They, at the University of Breslau, but also at other German universities, had joined the student fraternities in the 20-ies and early 30-ies of the 19th century and, in consequence, were persecuted by state authorities, notably in Prussia and, in the majority of cases, had been sentenced to prison terms of varying degrees. The first demagogic persecution, which happened in the first half of the twenties, culminating in 1822 in the Breslau Arminen Trail and ending up with the staging of the Youth-Association-Trail in 1826, had implicated about 100 Silesians, with a smaller portion of them - apart from teh three Youth-Association Silesians who were sentenced to five years imprisonment in a fortress - getting away with a relatively short "political fortress imprisonment". Later a considerable part of them made a career in the prussian judicial authority, in the institutions of higher learning, as parish priests, physicians and scientists, whereas any political engagement remained a rare exception. Out of the 137 Silesian members of the student fraternities affected by the second wave of persecution, the overwhelming majority of them being Protestants and originating partly from the middle classes, mostly artisans, and from intellectual background, with about a hundred of them being given essentially higher sentences ranging from six years up to capital punishment and, in the event of reprieves, they had to serve their sentences between six months and four-to-six years in a fortress. The majority of them made a medium-level professional career, never exceeding the medium ranks, as judicial officers, lawyers in state or communal services, parish priests, teachers or physicians. However, from this group of persecuted persons, a

  13. PREFACE: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19)

    NASA Astrophysics Data System (ADS)

    González, T.; Martín-Martínez, M. J.; Mateos, J.

    2015-10-01

    The 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19) was held at the Hospedería Fonseca (Universidad de Salamanca, Spain), on 29 June - 2 July, 2015, and was organized by the Electronics Area from the University of Salamanca. The Conference is held biannually and covers the recent progress in the field of electron dynamics in solid-state materials and devices. This was the 19th meeting of the international conference series formerly named Hot Carriers in Semiconductors (HCIS), first held in Modena in 1973. In the edition of 1997 in Berlin the name of the conference changed to International Conference on Nonequilibrium Carrier Dynamics in Semiconductors, keeping the same acronym, HCIS; and finally in the edition of Montpellier in 2009 the name was again changed to the current one, International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON). The latest editions took place in Santa Barbara, USA, in 2011 and Matsue, Japan, in 2013. Research work on electron dynamics involves quite different disciplines, and requires both fundamental and technological scientific efforts. Attendees to the conference come mostly from academic institutions, belonging to both theoretical and experimental groups working in a variety of fields, such as solid-state physics, electronics, optics, electrical engineering, material science, laser physics, etc. In this framework, events like the EDISON conference become a basic channel for the progress in the field. Here, researchers working in different areas can meet, present their latest advances and exchange their ideas. The program of EDISON'19 included 13 invited papers, 61 oral contributions and 73 posters. These contributions originated from scientists in more than 30 different countries. The Conference gathered 140 participants, coming from 24 different countries, most from Europe, but also with a significant participation

  14. 19th century London dust-yards: a case study in closed-loop resource efficiency.

    PubMed

    Velis, Costas A; Wilson, David C; Cheeseman, Christopher R

    2009-04-01

    The material recovery methods used by dust-yards in early 19th century London, England and the conditions that led to their development, success and decline are reported. The overall system developed in response to the market value of constituents of municipal waste, and particularly the high coal ash content of household 'dust'. The emergence of lucrative markets for 'soil' and 'breeze' products encouraged dust-contractors to recover effectively 100% of the residual wastes remaining after readily saleable items and materials had been removed by the thriving informal sector. Contracting dust collection to the private sector allowed parishes to keep the streets relatively clean, without the need to develop institutional capacity, and for a period this also generated useful income. The dust-yard system is, therefore, an early example of organised, municipal-wide solid waste management, and also of public-private sector participation. The dust-yard system had been working successfully for more than 50 years before the Public Health Acts of 1848 and 1875, and was thus important in facilitating a relatively smooth transition to an institutionalised, municipally-run solid waste management system in England. The dust-yards can be seen as early precursors of modern materials recycling facilities (MRFs) and mechanical-biological treatment (MBT) plants; however, it must be emphasised that dust-yards operated without any of the environmental and occupational health considerations that are indispensable today. In addition, there are analogies between dust-yards and informal sector recycling systems currently operating in many developing countries.

  15. The lost origin of chemical ecology in the late 19th century.

    PubMed

    Hartmann, Thomas

    2008-03-25

    The origin of plant chemical ecology generally dates to the late 1950s, when evolutionary entomologists recognized the essential role of plant secondary metabolites in plant-insect interactions and suggested that plant chemical diversity evolved under the selection pressure of herbivory. However, similar ideas had already flourished for a short period during the second half of the 19th century but were largely forgotten by the turn of the century. This article presents the observations and studies of three protagonists of chemical ecology: Anton Kerner von Marilaun (1831-1898, Innsbruck, Austria, and Vienna, Austria), who mainly studied the impact of geological, climatic, and biotic factors on plant distribution and survival; Léo Errera (1858-1906, Brussels, Belgium), a plant physiologist who analyzed the localization of alkaloids in plant cells and tissues histochemically; and Ernst Stahl (1848-1919, Jena, Germany), likely the first experimental ecologist and who performed feeding studies with snails and slugs that demonstrated the essential role of secondary metabolites in plant protection against herbivores. All three, particularly Stahl, suggested that these "chemical defensive means" evolved in response to the relentless selection pressure of the heterotrophic community that surrounds plants. Although convincingly supported by observations and experiments, these ideas were forgotten until recently. Now, more than 100 years later, molecular analysis of the genes that control secondary metabolite production underscores just how correct Kerner von Marilaun, Errera, and, particularly, Stahl were in their view. Why their ideas were lost is likely a result of the adamant rejection of all things "teleological" by the physiologists who dominated biological research at the time.

  16. The lost origin of chemical ecology in the late 19th century

    PubMed Central

    Hartmann, Thomas

    2008-01-01

    The origin of plant chemical ecology generally dates to the late 1950s, when evolutionary entomologists recognized the essential role of plant secondary metabolites in plant–insect interactions and suggested that plant chemical diversity evolved under the selection pressure of herbivory. However, similar ideas had already flourished for a short period during the second half of the 19th century but were largely forgotten by the turn of the century. This article presents the observations and studies of three protagonists of chemical ecology: Anton Kerner von Marilaun (1831–1898, Innsbruck, Austria, and Vienna, Austria), who mainly studied the impact of geological, climatic, and biotic factors on plant distribution and survival; Léo Errera (1858–1906, Brussels, Belgium), a plant physiologist who analyzed the localization of alkaloids in plant cells and tissues histochemically; and Ernst Stahl (1848–1919, Jena, Germany), likely the first experimental ecologist and who performed feeding studies with snails and slugs that demonstrated the essential role of secondary metabolites in plant protection against herbivores. All three, particularly Stahl, suggested that these “chemical defensive means” evolved in response to the relentless selection pressure of the heterotrophic community that surrounds plants. Although convincingly supported by observations and experiments, these ideas were forgotten until recently. Now, more than 100 years later, molecular analysis of the genes that control secondary metabolite production underscores just how correct Kerner von Marilaun, Errera, and, particularly, Stahl were in their view. Why their ideas were lost is likely a result of the adamant rejection of all things “teleological” by the physiologists who dominated biological research at the time. PMID:18218780

  17. Forgotten research from 19th century: science should not follow fashion.

    PubMed

    Galler, Stefan

    2015-02-01

    The fine structure of cross-striated muscle and its changes during contraction were known already in considerable detail in the 19th century. This knowledge was the result of studying birefringence properties of muscle fibres under the polarization microscope, a method mainly established by Brücke (Denk Kais Akad Wiss Math Naturwiss Cl 15:69-84, 1858) in Vienna, Austria. The knowledge was seemingly forgotten in the first half of the 20th century before it was rediscovered in 1954. This rediscovery was essential for the formulation of the sliding filament theory which represents the commonly accepted concept of muscle contraction (A.F. Huxley and Niedergerke, Nature 173:971-973, 1954; H.E. Huxley and Hanson, Nature 173:973-976, 1954). The loss of knowledge was the result of prevailing views within the scientific community which could be attributed to "fashion": it was thought that the changes of cross-striations, which were observed under the microscope, were inconsequential for contraction since other types of movements like cell crawling and smooth muscle contraction were not associated with similar changes of the fine structure. The basis for this assumption was the view that all types of movements associated with life must be caused by the same mechanisms. Furthermore, it was assumed that the light microscopy was of little use, because the individual molecules that carry out life functions cannot be seen under the light microscope. This unfortunate episode of science history teaches us that the progress of science can severely be retarded by fashion.

  18. The Variability of Solar Spectral Irradiance and Solar Surface Indices Through the Solar Activity Cycles 21-23

    NASA Astrophysics Data System (ADS)

    Deniz Goker, Umit

    2016-07-01

    A study of variations of solar spectral irradiance (SSI) in the wavelength ranges 121.5 nm-300.5 nm for the period 1981-2009 is presented. We used various data for ultraviolet (UV) spectral lines and international sunspot number (ISSN) from interactive data centers as SME (NSSDC), UARS (GDAAC), SORCE (LISIRD) and SIDC, respectively. We developed a special software for extracting the data and reduced this data by using the MATLAB. In this respect, we revealed negative correlations of intensities of UV (289.5 nm-300.5 nm) emission lines originating in the solar chromosphere with the ISSN index during the unusually prolonged minimum between the solar cycles (SCs) 23 and 24. We also compared our results with the ground-based telescopes as Solar Irradiance Platform, Stanford Data (SFO), Kodaikanal Data (KKL) and NGDC Homepage (Rome and Learmonth Solar Observatories). We studied the variations of total solar irradiance (TSI), magnetic field, sunspots/sunspot groups, Ca II K-flux, faculae and plage areas data with these ground-based telescopes, respectively. We reduced the selected data using the Phyton programming language and plot with the IDL programme. Therefore, we found that there was a decrease in the area of bright faculae and chromospheric plages while the percentage of dark faculae and plage decrease, as well. However, these decreases mainly occurred in small sunspots, contrary to this, these terms in large sunspot groups were comparable to previous SCs or even larger. Nevertheless, negative correlations between ISSN and SSI data indicate that these emissions are in close connection with the classes of sunspots/sunspot groups and "PLAGE" regions. Finally, we applied the time series of the chemical elements correspond to the wavelengths 121.5 nm-300.5 nm and compared with the ISSN data. We found an unexpected increasing in the 298.5 nm for the Fe II element. The variability of Fe II (298.5 nm) is in close connection with the plage regions and the sizes of the

  19. On the Influence of the Solar Bi-Cycle on Comic Ray Modulatio

    NASA Astrophysics Data System (ADS)

    Lifter, N. Part Xxvii: A. Defect Of The Solar Dynamo. B.; Scissors, K.; Sprucener, H.

    In this presentation we propose a new paradigm that explains the different lengths of individual solar Hale cycles. It proves beneficial to distinguish between a so-called inHale and ex-Hale cycle, which together form the solar bi-cycle. We carefully analyzed the influence 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 solar 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 solar dynamo can no longer operate efficiently, i.e. is defect.

  20. The spatial distribution of the association between total ozone and the 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Labitzke, K.; van Loon, H.

    1992-02-01

    The pattern of correlation between the 11-year solar cycle and heights and temperatures in the lower stratosphere is in all months shaped as a crescent with its axis in the subtropics. The change of total ozone from the solar maximum in 1979-1980 to the minimum in 1985-1986 has the same shape. Although the effect of the solar cycle is said to have been removed from the ozone data, two thirds of the stations which have been used for this purpose lie outside the regions where the stratosphere is significantly correlated with the solar cycle. For this reason it is unlikely that the influence of the cycle has been completely eliminated.

  1. Long-Range Solar Activity Predictions: A Reprieve from Cycle #24's Activity

    NASA Technical Reports Server (NTRS)

    Richon, K.; Schatten, K.

    2003-01-01

    We discuss the field of long-range solar activity predictions and provide an outlook into future solar activity. Orbital predictions for satellites in Low Earth Orbit (LEO) depend strongly on exospheric densities. Solar activity forecasting is important in this regard, as the solar 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 solar activity. It was later extended to solar 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 SOlar Dynamo Amplitude (SODA) index. The SODA index is a measure of the buried solar magnetic flux, using toroidal and poloidal field components. It allows one to predict future solar activity during any phase of the solar cycle, whereas previously, one was restricted to making predictions only at solar minimum. We are encouraged that solar 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 solar 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 solar activity can be predicted. Although a degree of uncertainty

  2. Solar activity cycle and the incidence of foetal chromosome abnormalities detected at prenatal diagnosis

    NASA Astrophysics Data System (ADS)

    Halpern, Gabrielle J.; Stoupel, Eliahu G.; Barkai, Gad; Chaki, Rina; Legum, Cyril; Fejgin, Moshe D.; Shohat, Mordechai

    1995-06-01

    We studied 2001 foetuses during the period of minimal solar activity of solar cycle 21 and 2265 foetuses during the period of maximal solar activity of solar 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 solar activity suggests that a prospective study in a large population would be required to rule out any possible effect of extreme solar activity.

  3. Dynamic analysis of a closed-cycle solar adsorption refrigerator using two adsorbent-adsorbate pairs

    SciTech Connect

    Hajji, A. ); Worek, W. ); Lavan, Z. )

    1991-05-01

    In this paper a dynamic analysis of a closed-cycle, solar adsorption refrigerator is presented. The instantaneous and daily system performance are studied using two adsorbent-adsorbate pairs, Zeolite 13X-Water and Chabazite-Methanol. The effect of design and operating parameters, including inert material thermal capacitance, matrix porosity, and evaporation and condenser temperatures on the solar and cycle coefficients of performance are evaluated.

  4. Differences in Properties of 3He-rich SEP Events between Solar Cycle 24 and Earlier Cycles

    NASA Astrophysics Data System (ADS)

    Wiedenbeck, M. E.; Mason, G. M.; Ho, G. C.

    2013-12-01

    Since the launch of NASA's ACE spacecraft in 1997 we have been observing 3He-rich solar energetic particle (SEP) events using its ULEIS and SIS instruments. From those data it was determined that over the past 15+ years there has been a large variation in the fraction of time that energetic 3He could be detected near Earth, ranging from >80% near the maximum of solar cycle 23 to <2% in the minimum between cycles 23 and 24. In addition, it is now apparent that as the maximum of cycle 24 approaches this indicator of flare-related suprathermal ions is falling nearly a factor of 2 below the value observed in the previous cycle. The fraction of time with 3He present depends, however, on instrument sensitivity and thus our previous analyses did not directly address the question of whether the observed changes were due to the occurrence of fewer 3He-rich events with similar event characteristics, to having events with lower peak intensities and/or softer spectra, or to some combination of these effects. We have undertaken a more quantitative study of the solar cycle variation of 3He-rich SEP event properties to address this question. We use data from ACE and STEREO to characterize the events observed during the cycle 23/24 minimum and the cycle 24 maximum and compare them with ACE measurements from the cycle 23 maximum. In addition, we compare with published results obtained using instrumentation aboard ISEE-3 during the period spanning the maxima of cycles 21 and 22.

  5. ON POSSIBLE VARIATIONS OF BASAL Ca II K CHROMOSPHERIC LINE PROFILES WITH THE SOLAR CYCLE

    SciTech Connect

    Pevtsov, Alexei A.; Uitenbroek, Han; Bertello, Luca E-mail: huitenbroek@nso.edu

    2013-04-10

    We use daily observations of the Ca II K line profiles of the Sun-as-a-star taken with the Integrated Sunlight Spectrometer from 2006 December through 2011 July to deconvolve the contributions from the quiet (basal) chromosphere and with magnetic network/plage areas. The 0.5 A emission index computed from basal profiles shows a significantly reduced modulation (as compared with one derived from the observed profiles) corresponding to the Sun's rotation. For basal contribution of the Ca II K line, the peak in power spectrum corresponding to solar rotation is broad and not well defined. Power spectra for the plage contribution show two narrow well-defined peaks corresponding to solar rotation at two distinct latitudes, in agreement with the latitudinal distribution of activity on the Sun at the end of Cycle 23 and beginning of Cycle 24. We use the lack of a signature of solar rotation in the basal (quiet Sun) component as an indication of a successful removal of the active Sun (plage) component. Even though the contribution from solar activity is removed from the basal line profiles, we find a weak dependency of intensity in the line core (K3) of basal profiles with the phase of the solar cycle. Such dependency could be the result of changes in thermal properties of basal chromosphere with the solar cycle. As an alternative explanation, we also discuss a possibility that the basal component does not change with the phase of the solar cycle.

  6. Observations of Solar Spectral Irradiance Change During Cycle 22 from NOAA-9 SBUV/2

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew T.; Cebula, Richard P.; Hilsenrath, Ernest

    2003-01-01

    The NOM-9 Solar Backscatter Ultraviolet, model 2 (SBUV/2) instrument is one of a series of instruments providing daily solar spectral irradiance measurements in the middle and near ultraviolet since 1978. The SBUV/2 instruments are primarily designed to measure stratospheric profile and total column ozone, using the directional albedo as the input to the ozone processing algorithm. As a result, the SBUV/2 instrument does not have onboard monitoring of all time-dependent response changes. We have applied internal comparisons and vicarious (external) comparisons to determine the long-term instrument characterization for NOAA-9 SBUV/2 to derive accurate solar spectral irradiances from March 1985 to May 1997 spanning two solar cycle minima with a single instrument. The NOAA-9 data show an amplitude of 9.3(+/- 2.3)% (81-day averaged) at 200-205 nm for solar cycle 22. This is consistent with the result of (Delta)F(sub 200-205) = 8.3(+/- 2.6)% for cycle 21 from Nimbus-7 SBUV and (Delta)F(sub 200-205) = 10(+/- 2)% (daily values) for cycle 23 from UARS SUSIM. NOAA-9 data at 245-250 nm show a solar cycle amplitude of (Delta)F(sub 245-250) = 5.7(+/- 1.8)%. NOAA-9 SBUV/2 data can be combined with other instruments to create a 25-year record of solar UV irradiance.

  7. Theoretical study of the seasonal and solar cycle variations of stable aurora red arcs

    SciTech Connect

    Kozyra, J.U.; Valladares, C.E.; Carlson, H.C.; Buonsanto, M.J.; Slater, D.W.

    1990-08-01

    SAR arc statistic provide information on the seasonal and solar cycle variations in the subauroral region electron temperature peak and associated magnetospheric energy source. There are two sources of long-term (solar cycle and seasonal) variability in the magnitude of the subauroral region electron temperature peak and associated SAR are emission intensity: (1) the neutral atmosphere and ionosphere and (2) the magnetospheric energy source. The results of this study indicate that the observed seasonal variation in SAR are intensities can be explained reasonably well by seasonal variations in the neutral atmosphere and ionosphere. True solstice effect are unlikely to result from difference in a near-equatorial magnetospheric heat source since the same heat source supplies both the summer and the winter hemispheres at opposite ends of a common flux tube. Observed solar cycle variations in SAR are intensity for a fixed ring current strength (as represented by the D sub st index) are not consistent with variations predicted solely on the basis of a solar cycle changes in the neutral atmosphere and ionosphere. A reduction of the magnetospheric heat flux by a factor of between 5 and 20 from solar maximum to solar minimum conditions is necessary to bring model electron temperatures and 6300 emission intensity into agreement with observational results for moderately disturbed conditions D sub st approx - 80 gamma. The required reduction in the magnetospheric energy source with decreasing solar cycle is attributed to compositional changes in the magnetospheric plasma.

  8. Influence of the 11-Year Solar Cycle on Variations of Cosmic Ray Intensity

    NASA Astrophysics Data System (ADS)

    Ma, L. H.; Han, Y. B.; Yin, Z. Q.

    2009-03-01

    The monthly cosmic ray intensity (CRI) time series from Climax, Huancayo, Moscow, Kiel, and Calgary are used to investigate the presence of the 11-year periodic component with special attention paid to the solar influence on these variations. The results show obvious 11-year temporal characteristics in CRI variations. We also find a close anticorrelation between the 11-year solar cycle and CRI variations and time delays of the CRI relative to solar activity.

  9. The Effects of a Nearly 100% Duty Cycle in Observations of Solar Oscillations

    NASA Technical Reports Server (NTRS)

    Hill, F.

    1984-01-01

    Power spectra of window functions with duty cycles between 80% and 99% and with randomly spaced gaps are compared and their effect on observations of solar oscillations are discussed. It is found that for all the cases, observations of solar oscillations would not be severely impacted as long as the gap structure is random rather than periodic.

  10. Relationships between solar activity and climate change. [sunspot cycle effects on lower atmosphere

    NASA Technical Reports Server (NTRS)

    Roberts, W. O.

    1974-01-01

    Recurrent droughts are related to the double sunspot cycle. It is suggested that high solar activity generally increases meridional circulations and blocking patterns at high and intermediate latitudes, especially in winter. This effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission.

  11. Effects of Solar UV Radiation and Climate Change on Biogeochemical Cycling: Interactions and Feedbacks

    EPA Science Inventory

    Solar UV radiation, climate and other drivers of global change are undergoing significant changes and models forecast that these changes will continue for the remainder of this century. Here we assess the effects of solar UV radiation on biogeochemical cycles and the interactions...

  12. The temperature of quiescent streamers during solar cycles 23 and 24

    SciTech Connect

    Landi, E.; Testa, P.

    2014-05-20

    Recent in-situ determinations of the temporal evolution of the charge state distribution in the fast and slow solar wind have shown a general decrease in the degree of ionization of all the elements in the solar wind along solar cycles 23 and 24. Such a decrease has been interpreted as a cooling of the solar corona which occurred during the decline and minimum phase of solar cycle 23 from 2000 to 2010. In the present work, we investigate whether spectroscopic determinations of the temperature of the quiescent streamers show signatures of coronal plasma cooling during cycles 23 and 24. We measure the coronal electron density and thermal structure at the base of 60 quiescent streamers observed from 1996 to 2013 by SOHO/SUMER and Hinode/EIS and find that both quantities do now show any significant dependence on the solar cycle. We argue that if the slow solar wind is accelerated from the solar photosphere or chromosphere, the measured decrease in the in-situ wind charge state distribution might be due to an increased efficiency in the wind acceleration mechanism at low altitudes. If the slow wind originates from the corona, a combination of density and wind acceleration changes may be responsible for the in-situ results.

  13. An early prediction of the maximum amplitude of the solar cycle 25

    NASA Astrophysics Data System (ADS)

    Helal, Hamid R.; Galal, A. A.

    2013-05-01

    A solar activity precursor technique of spotless event has been currently used to predict the strengths and the times of rise of the 11-year coming cycles. This simple statistical method has been previously applied to predict the maximum amplitudes and the times of rises of cycles 22 and 23. The results obtained are successful for both cycles. A developed version of the suggested method was previously used to make an early forecast of the characteristic parameters of the cycle 24. In this work the preliminarily predicted parameters of the cycle 24 are checked using observed values of the spotless events. In addition, the developed method is also applied to forecast the maximum amplitude and time of rise of the 25th solar cycle. The maximum Wolf number and time of rise of the latter cycle are found to be 118.2 and 4.0 years respectively.

  14. Anomalous Expansion of Coronal Mass Ejections During Solar Cycle 24 and Its Space Weather Implications

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji; Xie, Hong; Makela, Pertti; Michalek, Grzegorz

    2014-01-01

    The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than those in cycle 23. The slope change indicates a significant change in the physical state of the heliosphere, due to the weak solar activity. The total pressure in the heliosphere (magnetic + plasma) is reduced by approximately 40%, which leads to the anomalous expansion of CMEs explaining the increased slope. The excess CME expansion contributes to the diminished effectiveness of CMEs in producing magnetic storms during cycle 24, both because the magnetic content of the CMEs is diluted and also because of the weaker ambient fields. The reduced magnetic field in the heliosphere may contribute to the lack of solar energetic particles accelerated to very high energies during this cycle.

  15. ON THE VARIATION OF SOLAR RADIUS IN ROTATION CYCLES

    SciTech Connect

    Qu, Z. N.; Kong, D. F.; Xiang, N. B.; Feng, W.

    2015-01-10

    The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.

  16. Life Cycle Greenhouse Gas Emissions from Solar Photovoltaics (Fact Sheet)

    SciTech Connect

    Not Available

    2012-11-01

    The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that helps to clarify inconsistent and conflicting life cycle GHG emission estimates in the published literature and provide more precise estimates of life cycle GHG emissions from PV systems.

  17. The role of ozone feedback in modulating the atmospheric response to the solar cycle forcing

    NASA Astrophysics Data System (ADS)

    Bednarz, Ewa; Maycock, Amanda; Braesicke, Peter; Telford, Paul; Abraham, Luke; Pyle, John

    2016-04-01

    The irradiance changes between the 11-year solar cycle maximum and minimum lead to increased stratospheric temperatures via enhanced UV absorption by ozone. This direct radiative response is strengthened by increased photochemical ozone production. While in reality these two processes are closely coupled, not all global climate models include interactive chemistry and may not therefore represent the solar-ozone feedback in an internally consistent manner. This study investigates the role of the representation of ozone for the modeled solar cycle response. We use a version of the UM-UKCA chemistry-climate model. We perform a 64-year perpetual solar minimum integration with non-interactive treatment of ozone, i.e. where ozone is externally prescribed for the radiative calculations. This is complemented with two analogous non-interactive solar maximum integrations that include an increase in solar irradiance, but which differ in their representation of the solar ozone response. We show that the representation of the solar-ozone feedback has a first-order impact on the simulated yearly mean short wave heating rates and temperature responses to the 11-year solar cycle forcing. However, despite the substantial differences in the tropical temperature changes, the Northern Hemisphere high latitude circulation responses are broadly similar in both experiments, and show strengthening of the polar vortex during winter and a weakening in March. Therefore, the representation of the prescribed solar-ozone response appears unlikely to explain the substantial spread in the solar cycle dynamical responses in different models. Lastly, we compare these results with an analogous solar maximum/minimum pair in which ozone is calculated by the photochemical scheme in a self-consistent manner. We show that the use of interactive vs non-interactive treatment of ozone does not strongly affect the yearly mean tropical temperature response. However, the results suggest potential differences

  18. Coronal Dynamic Activities in the Declining Phase of a Solar Cycle

    NASA Astrophysics Data System (ADS)

    Jang, Minhwan; Woods, T. N.; Hong, Sunhak; Choe, G. S.

    2016-12-01

    It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this Letter, we investigate the high solar dynamic activity in the declining phase of the sunspot cycle by examining the evolution of polar and low-latitude coronal hole (CH) areas, splitting and merging events of CHs, and coronal mass ejections (CMEs) detected by SOHO/LASCO C3 in solar cycle 23. Although the total CH area is at its maximum near the sunspot minimum, in which polar CHs prevail, it shows a comparable second maximum in the declining phase of the cycle, in which low-latitude CHs are dominant. The events of CH splitting or merging, which are attributed to surface motions of magnetic fluxes, are also mostly populated in the declining phase of the cycle. The far-reaching C3 CMEs are also overpopulated in the declining phase of the cycle. From these results we suggest that solar dynamic activities due to the horizontal surface motions of magnetic fluxes extend far in the declining phase of the sunspot cycle.

  19. The study of the solar cycle and its irregularities using dynamo models

    NASA Astrophysics Data System (ADS)

    Binay Karak, Bidya

    The solar cycle is not regular. The strength as well as the period varies from cycle to cycle. One puzzling aspect of this sunspot cycle is the Maunder minimum in 17th century when sunspots disappeared for about 70 years. Indirect studies suggest that there were several other such events in the past. The motivation of our work will be first to understand the generation and the evolution of the large-scale magnetic field of the Sun and then to model some irregular features of the solar cycle. We shall present a flux transport dynamo model to study the evolution of magnetic fields in the Sun. In this model the toroidal field is generated by the strong differential rotation near the base of the convection zone and the poloidal field is generated near the solar surface from the decay of sunspots. The turbulent diffusion, the meridional circulation and the turbulent pumping are the important flux transport agents in this model which communicate these two spatially segregated source regions of the magnetic field. With this dynamo model, the speaker shall explain several aspects of the solar cycle including the grand minima. We shall also discuss the predictability of the future solar cycle using dynamo models.

  20. Two Types of Coronal Bright Points in the 24-th Cycle of Solar Activity

    NASA Astrophysics Data System (ADS)

    Sherdanov, Chori T.; Minenko, Ekaterina P.; Tillaboev, A. M.; Sattarov, Isroil

    We applied an automatic program for identification of coronal bright points (CBPs) to the data obtained by SOHO/EIT observations taken at the wavelength 195 Å, in the time interval from the end of the 23rd to the early 24th solar cycle. We studied the total number of CBPs and its variations at the beginning of the given cycle of solar activity, so that the development of the solar activity could be predicted with the use of CBPs. For a primary reference point for the 24th solar cycle, we took the emergence of a high-latitude sunspot with the reversed polarity, which appeared in January, 2008. We show that the observed number of CBPs reaches the highest point around the minimum of the solar activity, which in turn may result from the effect of visibility. The minimum solar activity at this time provides the opportunity to register the number of CBPs with the highest accuracy, with its uniform latitudinal distribution. We also study the properties of CBPs in a new 24th cycle of solar activity. It is shown that variations in the cyclic curve of the number of coronal bright points associated with variations in the solar activity, for the latitudes of the quiet Sun to be anticorrelation characteristic changes in the number CBPs to the solar activity, and the observational data are for the regions of active formations on the Sun almost identical on character on the equatorial latitude, but this have lightly expressed character in high-latitude zone. To explain the cyclic curves of variation in the number of coronal bright points in connection with the solar cycle in different latitudinal zones, we suggest a hypothesis of the existence of two types of coronal bright points: those associated with the quiet corona and those related to active formations.

  1. Principal Component Analysis of Solar Background and Sunspot Magnetic Field in cycles 21-24 and its implications for the solar activity prediction in cycles 25-27

    NASA Astrophysics Data System (ADS)

    Zharkova, Valentina; Popova, Helen; Zharkov, Sergei; Shepherd, Simon

    Principle component analysis (PCA) of the solar background magnetic field (SBMF) measured from Wilcox Solar Observatory (WSO) and sunspot magnetic field (SMF) measured by SOHO/MDI magnetograms reveals the two principal components (PCs) of waves travelling in time. In addition, the independent components analysis helps to uncover 8 pairs of SBMF waves in latitudes: two large symmetric magnetic waves , which are the same for all cycles 21-23, and three pairs of asymmetric magnetic waves, which are unique for each cycle. In each pair the waves travel slightly off phase with different phase shift for each cycle and have a different number of equator crossings (Zharkova et al, 2012). These SBMF variations are assumed to be those of poloidal magnetic field traveling slightly off-phase from pole to pole which are caused by a joint action of dipole and quadruple magnetic sources in the Sun. The simulations with the two layer Parker's dynamo model with meridional circulation revealed that the dominant pair of PCs can be produced by a magnetic dipole accounting for the two main dynamo waves operating between the two magnetic poles. The further three pairs of the waves are unique to each cycle and associated with the multiple magnetic sources in the solar interior: with a quadruple symmetry in both layers for cycle 21, with quadruple magnetic sources in the upper layer and dipole sources in the inner layer for cycle 22 and with the quadruple magnetic sources in the inner layer and the dipole sources in the upper layer for cycle 23 (Popova et al, 2013). The PCs derived for all three cycles from SMBF were used as a training set for the magnetic wave prediction for the cycles 24-27 by using Hamiltonian approach (Shepherd and Zharkova, 2014) and verifying by the SBMF observations in the current cycle 24. The prediction results indicate that the solar activity is defined mainly by the solar background magnetic fields while the sunspots and their magnetic fields seem to be

  2. Sunspot group tilt angles and the strength of the solar cycle

    NASA Astrophysics Data System (ADS)

    Dasi-Espuig, M.; Solanki, S. K.; Krivova, N. A.; Cameron, R.; Peñuela, T.

    2010-07-01

    Context. It is well known that the tilt angles of active regions increase with their latitude (Joy's law). It has never been checked before, however, whether the average tilt angles change from one cycle to the next. Flux transport models show the importance of tilt angles for the reversal and build up of magnetic flux at the poles, which is in turn correlated to the strength of the next cycle. Aims: Here we analyse time series of tilt angle measurements and look for a possible relationship of the tilt angles with other solar cycle parameters, in order to glean information on the solar dynamo and to estimate their potential for predicting solar activity. Methods: We employed tilt angle data from Mount Wilson and Kodaikanal observatories covering solar cycles 15 to 21. We analyse the latitudinal distribution of the tilt angles (Joy's law), their variation from cycle to cycle, and their relationship to other solar cycle parameters, such as the strength (or total area covered by sunspots in a cycle), amplitude, and length. Results: The two main results of our analysis follow. 1. We find an anti-correlation between the mean normalised tilt angle of a given cycle and the strength (or amplitude) of that cycle, with a correlation coefficient of rc = -0.95 (99.9% confidence level) and rc = -0.93 (99.76% confidence level) for Mount Wilson and Kodaikanal data, respectively. 2. The product of the cycle's averaged tilt angle and the strength of the same cycle displays a significant correlation with the strength of the next cycle (rc = 0.65 at 89% confidence level and rc = 0.70 at 92% confidence level for Mount Wilson and Kodaikanal data, respectively). An even better correlation is obtained between the source term of the poloidal flux in Babcock-Leighton-type dynamos (which contains the tilt angle) and the amplitude of the next cycle. Further we confirm the linear relationship (Joy's law) between the tilt angle and latitude with slopes of 0.26 and 0.28 for Mount Wilson and

  3. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    SciTech Connect

    Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi

    2015-09-30

    Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities 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 activities 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 solar forcing energy to the Earth’s global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar 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 solar activity.

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

    NASA Astrophysics Data System (ADS)

    Lima, L. M.; Araújo, L. R.; Alves, E. O.; Batista, P. P.; Clemesha, B. R.

    2015-10-01

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

  5. HMI Observations of Solar Flares in Cycle 24

    NASA Astrophysics Data System (ADS)

    Hoeksema, J. Todd; Bobra, Monica; Couvidat, Sebastien; Sun, Xudong

    2015-08-01

    The Helioseismic and Magnetic Imager (HMI) on NASA’s Solar Dynamics Observatory (SDO) has continuously measured the vector magnetic field, intensity, and Doppler velocity in solar flares and over the entire solar disk since May 2010. The regular cadence of 45 seconds for line-of-sight and 12 minutes for vector measurements enables reliable investigations of photospheric conditions before, during, and after events both locally and globally. Active region indices can be tracked and conditions in the overlying corona can be modeled. A few examples show the utility of the data and demonstrate that some care must be exercised when the HMI data are used to investigate time variations.

  6. Technology for Bayton-cycle powerplants using solar and nuclear energy

    NASA Technical Reports Server (NTRS)

    English, R. E.

    1986-01-01

    Brayton cycle gas turbines have the potential to use either solar heat or nuclear reactors for generating from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power generating system. Their development for solar energy dynamic power generation for the space station could be the first step in an evolution of such powerplants for a very wide range of applications. At the low power level of only 10 kWe, a power generating system has already demonstrated overall efficiency of 0.29 and operated 38 000 hr. Tests of improved components show that these components would raise that efficiency to 0.32, a value twice that demonstrated by any alternate concept. Because of this high efficiency, solar Brayton cycle power generators offer the potential to increase power per unit of solar collector area to levels exceeding four times that from photovoltaic powerplants using present technology for silicon solar cells. The technologies for solar mirrors and heat receivers are reviewed and assessed. This Brayton technology for solar powerplants is equally suitable for use with the nuclear reactors. The available long time creep data on the tantalum alloy ASTAR-811C show that such Brayton cycles can evolve to cycle peak temperatures of 1500 K (2240 F). And this same technology can be extended to generate 10 to 100 MW in space by exploiting existing technology for terrestrial gas turbines in the fields of both aircraft propulsion and stationary power generation.

  7. Solar Cycle Propagation, Memory, and Prediction: Insights from a Century of Magnetic Proxies

    NASA Astrophysics Data System (ADS)

    Munoz-Jaramillo, Andres; Dasi-Espuig, M.; Balmaceda, L. A.; DeLuca, E. E.

    2013-07-01

    In the simplest of forms, modern dynamo theory describes the solar cycle as a process that takes the solar magnetic field (back and forth) from a configuration that is predominantly poloidal (contained inside the meridional plane), to one predominantly toroidal (wrapped around the axis of rotation). However, there is still uncertainty and controversy in the detailed understanding of this process. A major contributor to this uncertainty is the lack of direct long-term databases covering different components of the solar magnetic field (an issue mainly affecting the poloidal component of the solar magnetic field). In this talk we will review the different observations that can be used as proxies for the solar magnetic field (in absence of direct magnetic observations). I will present a recently standardized database that can be used as a proxy for the evolution of the polar magnetic field. And to conclude, I will show the insights that can be gained (by taking advantage of this database) in the context of the transition between the toroidal and poloidal phases of the cycle, solar cycle memory as determined by the different mechanisms of flux transport, and the practical goal of solar cycle prediction.

  8. Statistical study of strong and extreme geomagnetic disturbances and solar cycle characteristics

    NASA Astrophysics Data System (ADS)

    Kilpua, Emilia; Nigul, Olspert; Grigorievskiy, Alexander; Käpylä, Maarit; Tanskanen, Eija; Kataoka, Ryuho; Miyahara, Hiroko; Pelt, Jaan; Ying, Liu

    2016-04-01

    Extreme space weather storms are low-probability, but high-consequence events that may have a significant impact on the modern technological infrastructure in space and on ground. We present here the results on the correlation analysis between the occurrence of extreme geomagnetic storms and solar cycle characteristics using an extensive geomagnetic index AA data set spanning over 150 years (13 solar cycles) complemented by the Kakioka magnetometer recordings. Our results show that the correlation between the storm occurrence and the strength of solar cycle decreases from a clear positive correlation with increasing storm magnitude towards a negligible relationship. Hence, also the calmer Sun can launch super-storms. Examples of such events are the Carrington storm in 1859 and the July 2012 CME that impacted the STEREO-A spacecraft, both of which occurred during relatively weak solar cycles. Our results further suggest that while weaker storms occur most frequently in the declining phase the most extreme storms have a tendency to occur near solar maximum. We also discuss the implications of our findings for the connection between the extreme solar eruptions and multi-scale solar dynamo generated magnetic fields.

  9. Musical expressions of life: a look at the 18th and 19th century from a human becoming perspective.

    PubMed

    Jonas-Simpson, Christine

    2004-10-01

    What follows is an exploration of 18th and 19th century music of the Western world through a nursing science lens, specifically that of the human becoming theory. This article was written while I was enrolled in a music history course, which afforded me the opportunity to explore music as musical expressions of life. Rooted in the human becoming philosophical perspective, which focuses on unitary human experience and the quality of human life, I discuss musical expressions of life with examples from various composers throughout the 18th and 19th century. This article concludes with a reflection on musical expressions and their contribution to the enhancement of the quality of human life, a focus of nursing from a human becoming perspective.

  10. [The construction of a medical discipline and its challenges: Orthopedics in Switzerland during the 19th and 20th centuries].

    PubMed

    Kaba, Mariama

    2015-07-01

    During the 19th century, numerous figures, with different qualifications, claimed to practice orthopedics: doctors, surgeons, inventors of equipment and instruments, and other empiricists. They performed certain types of techniques, massages, surgical operationsand/or fitted prostheses. The polysemous notion of orthopedics had created conflicts of interest that would reach their height at the end of the 19th century. The integration of orthopedics into the training at the university level enhanced its proximity to surgery, a discipline that has dominated the so-called modern medicine. During the 20th century, various medical branches defend the legitimacy of certain orthopedic practices, thereby threating to a degree the title itself of this specialization. By examining the challenges that have shaped the history of orthopedics in Switzerland, this article also seeks to shed light on the strategies that were implemented in adopting a medical and technical discipline within a transforming society.

  11. The Lowland Rivers of The Netherlands - Geodiversity and Cultural Heritage on 19th and early 20th century Landscape Paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Moes, Constance

    2015-04-01

    One of the major Dutch landscapes is formed by lowland rivers. They divide the country in a southern and a northern part, both physically and culturally. We screened the freely available database of 19th and early 20th century paintings of Simonis & Buunk, www.simonis-buunk.com, looking for lowland river landscapes depicting geodiversity and cultural heritage relationships (See References for other landscapes). Emperor Napoleon declared The Netherlands as naturally belonging to his empire as its lands originated from muds originating in France and transported there by the big rivers. A description that may have given rise to the idea of the Netherlands as a delta, but from a geomorphological perspective The Netherlands consists of series of river plains of terrestrial origin, of which the north-western part are subsiding and invaded by the sea. Now, the rivers Meuse and Rhine (including its branches Waal and IJssel) meander through ever larger river plains before reaching the North Sea. They end in estuaries, something one would not expect of rivers with catchments discharging a large part of Western Europe. Apart from the geological subsidence, the estuaries might be due to human interference, the exploitation of peat and building of dikes since the 11th century, heavy storms and the strong tidal currents. Archaeological finds show Vikings and Romans already used the river Rhine system for trading and transporting goods. During the Roman Empire the Rhine was part of The Limes, the northern defence line of the empire. Romans already influenced the distribution of water over the different river branches. Since the middle of the 19th century groins and canalization drastically changed the character of the rivers. The 19th and early 20th century landscape paintings illustrate this change as well as changes in land use. Examples of geodiversity and cultural heritage relationships shown: - meanders and irregular banks disappear as river management increases, i.a. bends

  12. Probability density functions for the variable solar wind near the solar cycle minimum

    NASA Astrophysics Data System (ADS)

    Vörös, Z.; Leitner, M.; Narita, Y.; Consolini, G.; Kovács, P.; Tóth, A.; Lichtenberger, J.

    2015-08-01

    Unconditional and conditional statistics are used for studying the histograms of magnetic field multiscale fluctuations in the solar wind near the solar cycle minimum in 2008. The unconditional statistics involves the magnetic data during the whole year in 2008. The conditional statistics involves the magnetic field time series split into concatenated subsets of data according to a threshold in dynamic pressure. The threshold separates fast-stream leading edge compressional and trailing edge uncompressional fluctuations. The histograms obtained from these data sets are associated with both multiscale (B) and small-scale (δB) magnetic fluctuations, the latter corresponding to time-delayed differences. It is shown here that, by keeping flexibility but avoiding the unnecessary redundancy in modeling, the histograms can be effectively described by a limited set of theoretical probability distribution functions (PDFs), such as the normal, lognormal, kappa, and log-kappa functions. In a statistical sense the model PDFs correspond to additive and multiplicative processes exhibiting correlations. It is demonstrated here that the skewed small-scale histograms inherent in turbulent cascades are better described by the skewed log-kappa than by the symmetric kappa model. Nevertheless, the observed skewness is rather small, resulting in potential difficulties of estimation of the third-order moments. This paper also investigates the dependence of the statistical convergence of PDF model parameters, goodness of fit, and skewness on the data sample size. It is shown that the minimum lengths of data intervals required for the robust estimation of parameters is scale, process, and model dependent.

  13. Solar-cycle variations of large frequency separations of acoustic modes: implications for asteroseismology

    NASA Astrophysics Data System (ADS)

    Broomhall, A.-M.; Chaplin, W. J.; Elsworth, Y.; New, R.

    2011-06-01

    We have studied solar-cycle changes in the large frequency separations that can be observed in Birmingham Solar Oscillations Network (BiSON) data. The large frequency separation is often one of the first outputs from asteroseismic studies because it can help constrain stellar properties like mass and radius. We have used three methods for estimating the large separations: use of individual p-mode frequencies, computation of the autocorrelation of frequency-power spectra, and computation of the power spectrum of the power spectrum. The values of the large separations obtained by the different methods are offset from each other and have differing sensitivities to the realization noise. A simple model was used to predict solar-cycle variations in the large separations, indicating that the variations are due to the well-known solar-cycle changes to mode frequency. However, this model is only valid over a restricted frequency range. We discuss the implications of these results for asteroseismology.

  14. The importance of facular and plage data for the understanding of the solar cycle

    NASA Astrophysics Data System (ADS)

    Petrovay, Kristof

    Most global analyses of the solar activity cycle are based on sunspot data as other indicators such as F10.8 or flare data only cover the last few solar cycles. The only solar activity param-eter covering a historically significant time span is the facular area data set in the Greenwich catalogue. In this poster we first demonstrate the use of such data for the study of the solar cycle by considering similarities and differences in the Waldmeier effect in faculae as opposed to sunspots. The Greenwich catalogue was discontinued in 1976, so the extension of such studies to more recent times relies on "proxy" data such as plage areas; however, due to the short overlap in time, cross-calibration of these data has not been consistently made. We discuss the possibilities offered by SDO to cross-correlate facular areas with their proxies and to set up a new systematic data set of these activity indices.

  15. Comparing the solar magnetic field in the corona and in the inner heliosphere during solar cycles 21-23

    NASA Astrophysics Data System (ADS)

    Virtanen, I. I.; Mursula, K.

    2009-04-01

    We compare the open solar magnetic field estimated by the PFSS model based on the WSO photospheric field observations, with the inner heliospheric magnetic field. We trace the observed radial HMF into the coronal PFSS boundary at 2.5 solar radii using the observed solar wind velocity, and determine the PFSS model field at the line-of-sight footpoint. Comparing the two field values, we calculate the power n of the apparent decrease of the radial field. According to expectations based on Maxwell's equations, also reproduced by Parker's HMF model, the radial HMF field should decrease with n=2. However, comparison gives considerably lower values of n, indicating the effect of HCS in the PFSS model and the possible superexpansion. The n values vary with solar cycle, being roughly 1.3-1.4 at minima and about 1.7 at maxima. Interestingly, the n values for the two HMF sectors show systematic differences in the late declining to minimum phase, with smaller n values for the HMF sector dominant in the northern hemisphere. This is in agreement with the smaller field value in the northern hemisphere and the southward shifted HCS, summarized by the concept of the bashful ballerina. We also find that the values of n during the recent years, in the late declining phase of solar cycle 23, are significantly larger than during the same phase of the previous cycles. This agrees with the exceptionally large tilt of the solar dipole at the end of cycle 23. We also find that the bashful ballerina appears even during SC 23 but the related hemispheric differences are smaller than during the previous cycles.

  16. Stature in 19th and early 20th century Copenhagen. A comparative study based on skeletal remains.

    PubMed

    Jørkov, Marie Louise S

    2015-12-01

    Individual stature depends on multifactorial causes and is often used as a proxy for investigating the biological standard of living. While the majority of European studies on 19th and 20th century populations are based on conscript heights, stature derived from skeletal remains are scarce. For the first time in Denmark this study makes a comparison between skeletal stature and contemporary Danish conscript heights and investigates stature of males and females temporally and between socially distinct individuals and populations in 19th and early 20th century Copenhagen. A total of 357 individuals (181 males, 176 females) excavated at the Assistens cemetery in Copenhagen is analyzed. Two stature regression formulae (Trotter, 1970; Boldsen, 1990) are applied using femur measurements and evaluated compared to conscript heights. The results indicate that mean male stature using Boldsen follows a similar trend as the Danish conscript heights and that Trotter overestimate stature by ca. 6cm over Boldsen. At an inter population level statistically significant differences in male stature are observed between first and second half of the 19th century towards a slight stature decrease and larger variation while there are no significant changes observed in female stature. There are insignificant differences in stature between middle and high class individuals, but male stature differs statistically between cemeteries (p=0.000) representing middle/high class, paupers and navy employees, respectively. Female stature had no significant wealth gradient (p=0.516). This study provides new evidence of stature among males and females during the 19th century and suggests that males may have been more sensitive to changes in environmental living and nutrition than females.

  17. Starspots, stellar cycles and stellar flares: Lessons from solar dynamo models

    NASA Astrophysics Data System (ADS)

    Choudhuri, Arnab Rai

    2017-01-01

    In this review, we discuss whether the present solar dynamo models can be extrapolated to explain various aspects of stellar activity. We begin with a summary of the following kinds of data for solar-like stars: (i) data pertaining to stellar cycles from Ca H/K emission over many years; (ii) X-ray data indicating hot coronal activity; (iii) starspot data (especially about giant polar spots); and (iv) data pertaining to stellar superflares. Then we describe the current status of solar dynamo modelling—giving an introduction to the flux transport dynamo model, the currently favoured model for the solar cycle. While an extrapolation of this model to solar-like stars can explain some aspects of observational data, some other aspects of the data still remain to be theoretically explained. It is not clear right now whether we need a different kind of dynamo mechanism for stars having giant starspots or producing very strong superflares.

  18. An investigation of the solar cycle response of odd-nitrogen in the thermosphere

    NASA Technical Reports Server (NTRS)

    Rusch, David W.; Solomon, Stanley C.

    1992-01-01

    This annual report covers the first year of funding for the study of the solar cycle variations of odd-nitrogen (N((sup 2)D), N((sup 4)S), NO) in the Earth's thermosphere. The study uses the extensive data base generated by the Atmosphere Explorer (AE) satellites, and the Solar Mesosphere Explorer Satellite. The AE data are being used, for the first time, to define the solar variability effect on the odd-nitrogen species through analysis of the emissions at 520 nano-m from N((sup 2)D) and the emission from O(+)((sup 2)P). Additional AE neutral and ion density data are used to help define and quantify the physical processes controlling the variations. The results from the airglow study will be used in the next two years of this study to explain the solar cycle changes in NO measured by the Solar Mesosphere Explorer.

  19. Evidence for Luni - Solar mn and Solar Cycle sc Signals in Australian Rainfall Data

    NASA Astrophysics Data System (ADS)

    Currie, Robert G.; Vines, Robert G.

    1996-11-01

    Spectrum analysis of 308 yearly sampled Australian rainfall series yields evidence for two terms with periods 18.3 +/- 1.8 and 10.5 +/-0.7 years in 270 and 182 instances, respectively. The long-period term is statistically significant at a confidence level of 99.9 per cent. They are identified as the 18.6-year luni-solar Mn and 10-11-year solar cycle Sc signals previously reported in other climate data such as American and South African rainfall, tree-rings world-wide, rainfall indices, air temperature world-wide, air pressure world-wide, sea-level world-wide, river flow, American crop yields and livestock/poultry production, European fish catches and dates of wine harvest, varves, thunderstorm occurrence, Earth rotation, and volcanic eruptions. In eastern Australia, Mn wave minima were in phase with epochs 1880.3 and 1898.9 (epochs are dates of maxima in tidal forcing). At mid-epoch 1908.2, epoch 1917.5, and mid-epoch 1926.8 virtually all luni-solar wavetrains experienced a 180° change in phase. Thus, by 1936.1 virtually all the waves were out of phase with the epoch, a correlation that continued at epochs 1954.7 and 1973.3. An entirely analogous phenomenon occurred in USA rainfall data, but it occurred in the third quarter of our century. The contribution of the Mn and Sc signals to total variance in the raw data is on average 19 per cent. This is of course highly unrealistic - and when the power in the raw data from 8 to 2 years is filtered out prior to analysis, and the variance contribution of the signals to filtered data compared over a common frequency interval (periods 30 to 8 years), their variance contribution increases dramatically to a mean of 89 per cent. Currie carried out similar analyses for six sets of climate data comprising over 3200 records and found the mean variance contribution of signals to filtered data over a common bandwidth varied from 67 to 81 per cent. Thus, the spectrum of climate at decadal and duo- decadal periods is strongly

  20. Porcupine feeding scars and climatic data show ecosystem effects of the solar cycle.

    PubMed

    Klvana, Ilya; Berteaux, Dominique; Cazelles, Bernard

    2004-09-01

    Using North American porcupine (Erethizon dorsatum) feeding scars on trees as an index of past porcupine abundance, we have found that porcupine populations have fluctuated regularly over the past 130 years in the Bas St. Laurent region of eastern Quebec, with superimposed periodicities of 11 and 22 years. Coherency and phase analyses showed that this porcupine population cycle has closely followed the 11- and 22-year solar activity cycles. Fluctuations in local precipitation and temperature were also cyclic and closely related to both the solar cycle and the porcupine cycle. Our results suggest that the solar cycle indirectly sets the rhythm of population fluctuations of the most abundant vertebrate herbivore in the ecosystem we studied. We hypothesize that the solar cycle has sufficiently important effects on the climate along the southern shore of the St. Lawrence estuary to locally influence terrestrial ecosystem functioning. This constitutes strong evidence for the possibility of a causal link between solar variability and terrestrial ecology at the decadal timescale and local spatial scale, which confirms results obtained at greater temporal and spatial scales.

  1. Solar Cycle Slow to Get Going: What Does It Mean for Space Weather?

    NASA Astrophysics Data System (ADS)

    Turner, Ronald

    2011-04-01

    If you have the sense that the current solar cycle has been slow to build up, maybe it is more than just the “watched pot” failing to boil. A comparison with previous sunspot cycles shows that the current cycle is among the slowest-growing cycles characterized with good historical data. Figure 1 shows the smoothed sunspot number for the period from 2 years before the minimum to 2 years after it for the 24 numbered solar cycles (cycle 1 started in 1755; we are just now entering cycle 24). It illustrates the historically slow increase of the current cycle (shown in red) as of February 2011. Three of the four cycles with slower increases (shown in blue) were during the Dalton Minimum in the early nineteenth century. The fourth is the period leading into cycle 1. The red dots in the figure are cycle 24 monthly average sunspot numbers; these data are too recent to be adjusted by the smoothing algorithm that includes the influence of monthly averages within 6 months of the smoothed value. Also shown, at the bottom of the figure, for context, are the sunspot data for the first 23 cycles, which also identify the Dalton Minimum.

  2. Solar-cycle variation of the plasmasphere observed from the Akebono PWS data

    NASA Astrophysics Data System (ADS)

    Hasegawa, S.; Miyoshi, Y.; Kitamura, N.; Keika, K.; Kumamoto, A.; Machida, S.

    2013-12-01

    Plasmaspheric density structures have been studied for a long time. Although it has been clarified that the density is roughly constant along field lines in the outer plasmasphere [Goldstein et al., 2001; Denton et al., 2002, 2004], field-aligned density distributions of the inner plasmasphere has not been studied intensively. Moreover, continuous observation results longer than one-solar cycle have not been reported. Consequently, long-term variations of the plasmaspheric density over a solar cycle remains unknown. In this study, using electron density data based on plasma wave observations from the PWS experiments on board the Akebono satellite from 1989 to 2008, we conduct statistical analyses on variations of structures of the plasmasphere and plasmatrough. First, we select PWS data during geomagnetically quiet periods ( Kp less than or equal to 3 and Dst greater than or equal to -50 nT ), and derive spatial distributions as a function of L-magnetic local time and altitude-magnetic latitude. Second, assuming that densities along field lines are a function of geocentric distance R at an altitude of higher than 4000 km, we estimate the equatorial density and field-aligned density distributions. The equatorial plasma density and field-aligned density distributions depend on the L shell and the solar cycle. At small L shells ( L less than 3.7 ), field-aligned distributions do not clearly depend on solar cycle, and the estimated equatorial density tends to be small during the solar minimum. At large L shells ( L larger than or equal to 3.7 ) including the plasma trough and outside the plasmapause, on the other hand, field-aligned distributions vary with the solar cycle and the density tends to be low during the solar minimum. The equatorial density at the solar minimum is higher than that at the solar maximum.

  3. [The comparison of the two Ottoman books of anatomy (17-19th centuries) with regard to the circulatory system].

    PubMed

    Uluçam, E; Gökçe, N

    2000-01-01

    17th and 19th centuries were particularly important for the development of the Ottoman medicine. Westernization which had already started in the 17th century continued along the 19th and the early 20th centuries. Turkish physicians began to contact with their European colleagues and in this period Latin medical terminology began to appear in the Ottoman medical literature. Sirvanli Semseddin Itaki's work of the 17th century, the Teşrihü'l Ebdan ve Tercüman-i Kibale-i Feylesufan, is the first illustrated Turkish manuscript of anatomy. The illustrations are qualified as developed examples, compared with the medical literature and knowledge of the period. In the 19th century, Sanizade Mehmet Ataullah Efendi (1771-1826) wrote a modern book of anatomy for the Ottoman medical doctors. Miyarü'l Etibba was one of the earliest printed medical books in Turkish. The second volume of Sanizade's Hamse, Miratü'l Ebdan fi Teşrih-i Azai'l Insan is the first printed Ottoman book on anatomy. In Usulü't-Tabia, the third volume of Hamse, the circulatory system is discussed. In this article, we studied the circulatory system described in Semseddin Itaki's Teşrih-ül Ebdan ve Tercüman-i Kibale-i Feylesufan and in Sanizade's Usulü't-Tabia and compared them.

  4. Performance analysis of a solar-powered organic rankine cycle engine.

    PubMed

    Bryszewska-Mazurek, Anna; Swieboda, Tymoteusz; Mazurek, Wojciech

    2011-01-01

    This paper presents the performance analysis of a power plant with the Organic Rankine Cycle (ORC). The power plant is supplied by thermal energy utilized from a solar energy collector. R245fa was the working fluid in the thermodynamic cycle. The organic cycle with heat regeneration was built and tested experimentally. The ORC with a heat regenerator obtained the maximum thermodynamic efficiency of approximately 9%.

  5. Joseph Henry and John Henry Lefroy A common 19th century vision of auroral research

    NASA Astrophysics Data System (ADS)

    Silverman, S. M.

    Research on solar-terrestrial relationships today relies primarily on in situ space data. These data, however, cover only a short period of about 30 years. Many solar and related phenomena vary on much longer time scales. For the study of these, parameters such as sunspots, magnetic activity, auroral occurrence, or other proxy data are required. Historical records of aurora are particularly useful in this connection.

  6. SUSIM Measurements of UV Variations During the Decline of Solar Cycle 22

    NASA Astrophysics Data System (ADS)

    Floyd, L. E.; Crane, P. C.; Herring, L. C.; Prinz, D. K.; Brueckner, G. E.

    1997-05-01

    The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) aboard the Upper Atmosphere Research Satellite (UARS) has measured the solar spectral irradiance for wavelengths 1150-4100 { Angstroms} on every available day from October 11, 1991 to the present. The record of spectral irradiances obtained during this period clearly shows the decline associated with the last half of solar cycle 22. Superimposed on this solar cycle variation is a 27-day solar rotation modulation which, for the most part, maintains coherence across the wavelength spectrum and with SUSIM's own Mg II core-to-wing ratio index. However, for wavelengths between the Si I edge at 1682 { Angstroms} and the Mg I edge at 2513 { Angstroms} and for some time periods, 13.5-day variations dominate. SUSIM observations began when solar activity was near maximum and now extend through minimum. Generally, the measured peak-to-peak variations are larger for shorter wavelengths and for emission or absorption lines. The wavelength dependence of the UV variability apparently corresponds to the solar atmospheric emission heights given by radiative transfer models. The largest measured variation, that for H I Ly-alpha , exceeds a factor of two. The variation in the continuum just shortward of the Al I edge at 2076 { Angstroms} is about 10%; just longward, about 5%. This latter variation continues up to the Mg I edge and then declines to approximately zero measured variation at about 3000 { Angstroms} and above. Based on common proxies of solar UV variation, such as the Mg II core-to-wing ratio and He I 10830 { Angstroms} equivalent width, SUSIM irradiance measurements have ranged over more than 85% of the entire solar cycle 22 variation. Through the separate use of each index as a UV proxy, we extend the SUSIM measurements to estimate the wavelength-dependent peak-to-peak UV variability over the whole of solar cycle 22. SUSIM is supported under NASA-Defense Purchase Request S14798D.

  7. Scale Height variations with solar cycle in the ionosphere of Mars

    NASA Astrophysics Data System (ADS)

    Sanchez-Cano, Beatriz; Lester, Mark; Witasse, Olivier; Milan, Stephen E.; Hall, Benjamin E. S.; Cartacci, Marco; Radicella, Sandro M.; Blelly, Pierre-Louis

    2015-04-01

    The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on board the Mars Express spacecraft has been probing the topside of the ionosphere of Mars since June 2005, covering currently almost one solar cycle. A good knowledge of the behaviour of the ionospheric variability for a whole solar period is essential since the ionosphere is strongly dependent on solar activity. Using part of this dataset, covering the years 2005 - 2012, differences in the shape of the topside electron density profiles have been observed. These variations seem to be linked to changes in the ionospheric temperature due to the solar cycle variation. In particular, Mars' ionospheric response to the extreme solar minimum between end-2007 and end-2009 followed a similar pattern to the response observed in the Earth's ionosphere, despite the large differences related to internal origin of the magnetic field between both planets. Plasma parameters such as the scale height as a function of altitude, the main peak characteristics (altitude, density), the total electron content (TEC), the temperatures, and the ionospheric thermal pressures show variations related to the solar cycle. The main changes in the topside ionosphere are detected during the period of very low solar minimum, when ionospheric cooling occurs. The effect on the scale height is analysed in detail. In contrast, a clear increase of the scale height is observed during the high solar activity period due to enhanced ionospheric heating. The scale height variation during the solar cycle has been empirically modelled. The results have been compared with other datasets such as radio-occultation and retarding potential analyser data from old missions, especially in low solar activity periods (e.g. Mariner 4, Viking 1 and 2 landers), as well as with numerical modelling.

  8. SOLAR CYCLE VARIATIONS OF THE RADIO BRIGHTNESS OF THE SOLAR POLAR REGIONS AS OBSERVED BY THE NOBEYAMA RADIOHELIOGRAPH

    SciTech Connect

    Nitta, Nariaki V.; DeRosa, Marc L.

    2014-01-10

    We have analyzed daily microwave images of the Sun at 17 GHz obtained with the Nobeyama Radioheliograph (NoRH) in order to study the solar cycle variations of the enhanced brightness in the polar regions. Unlike in previous works, the averaged brightness of the polar regions is obtained from individual images rather than from synoptic maps. We confirm that the brightness is anti-correlated with the solar cycle and that it has generally declined since solar cycle 22. Including images up to 2013 October, we find that the 17 GHz brightness temperature of the south polar region has decreased noticeably since 2012. This coincides with a significant decrease in the average magnetic field strength around the south pole, signaling the arrival of solar maximum conditions in the southern hemisphere more than a year after the northern hemisphere. We do not attribute the enhanced brightness of the polar regions at 17 GHz to the bright compact sources that occasionally appear in synthesized NoRH images. This is because they have no correspondence with small-scale bright regions in images from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory with a broad temperature coverage. Higher-quality radio images are needed to understand the relationship between microwave brightness and magnetic field strength in the polar regions.

  9. On the dynamically driven temperature response in the middle atmosphere to the solar cycle signal.

    NASA Astrophysics Data System (ADS)

    Karlsson, Bodil; Kuilman, Maartje

    2016-04-01

    Noctilucent clouds (NLC), formed in the summer polar mesosphere, are exposed to solar radiation around the clock. These clouds consist of water ice, and are thus expected to be sensitive to changes in the solar Lyman alpha flux since it efficiently destroys water vapor in this region. Moreover, during solar maxima, the upper parts of the atmosphere are in general significantly warmer due to physical and chemical processes that are intensified at high solar activity. It is thus surprising that a clear solar cycle signal in NLC is hard to trace. We investigate how the circulation in the summer mesosphere is affected by changes in the solar flux using a 30-year run from the extended and nudged version of the Canadian Middle Atmosphere Model (CMAM30). We find that, as a result of a chain of wave-mean flow interactions primarily initiated in the winter stratosphere, the solar cycle signal from direct solar heating is suppressed by an enhanced circulation which adiabatically cools the region at increased solar activity.

  10. Contextualizing Solar Cycle 24: Report on the Development of a Homogenous Database of Bipolar Active Regions Spanning Four Cycles

    NASA Astrophysics Data System (ADS)

    Munoz-Jaramillo, A.; Werginz, Z. A.; DeLuca, M. D.; Vargas-Acosta, J. P.; Longcope, D. W.; Harvey, J. W.; Martens, P.; Zhang, J.; Vargas-Dominguez, S.; DeForest, C. E.; Lamb, D. A.

    2015-12-01

    The solar cycle can be understood as a process that alternates the large-scale magnetic field of the Sun between poloidal and toroidal configurations. Although the process that transitions the solar cycle between toroidal and poloidal phases is still not fully understood, theoretical studies, and observational evidence, suggest that this process is driven by the emergence and decay of bipolar magnetic regions (BMRs) at the photosphere. Furthermore, the emergence of BMRs at the photosphere is the main driver behind solar variability and solar activity in general; making the study of their properties doubly important for heliospheric physics. However, in spite of their critical role, there is still no unified catalog of BMRs spanning multiple instruments and covering the entire period of systematic measurement of the solar magnetic field (i.e. 1975 to present).In this presentation we discuss an ongoing project to address this deficiency by applying our Bipolar Active Region Detection (BARD) code on full disk magnetograms measured by the 512 (1975-1993) and SPMG (1992-2003) instruments at the Kitt Peak Vacuum Telescope (KPVT), SOHO/MDI (1996-2011) and SDO/HMI (2010-present). First we will discuss the results of our revitalization of 512 and SPMG KPVT data, then we will discuss how our BARD code operates, and finally report the results of our cross-callibration.The corrected and improved KPVT magnetograms will be made available through the National Solar Observatory (NSO) and Virtual Solar Observatory (VSO), including updated synoptic maps produced by running the corrected KPVT magnetograms though the SOLIS pipeline. The homogeneous active region database will be made public by the end of 2017 once it has reached a satisfactory level of quality and maturity. The Figure shows all bipolar active regions present in our database (as of Aug 2015) colored according to the sign of their leading polarity. Marker size is indicative of the total active region flux. Anti

  11. A Feasibility Study of CO2-Based Rankine Cycle Powered by Solar Energy

    NASA Astrophysics Data System (ADS)

    Zhang, Xin-Rong; Yamaguchi, Hiroshi; Fujima, Katsumi; Enomoto, Masatoshi; Sawada, Noboru

    An experiment study was carried out in order to investigate feasibility of CO2-based Rankine cycle powered by solar energy. The proposed cycle is to achieve a cogeneration of heat and power, which consists of evacuated solar tube collectors, power generating turbine, heat recovery system, and feed pump. The Rankine cycle of the system utilizes solar collectors to convert CO2 into high-temperature supercritical state, used to drive a turbine and produce electrical power. The cycle also recovers thermal energy, which can be used for absorption refrigerator, air conditioning, hot water supply so on for a building. A set of experimental set-up was constructed to investigate the performance of the CO2-based Rankine cycle. The results show the cycle can achieve production of heat and power with reasonable thermodynamics efficiency and has a great potential of the application of the CO2-based Rankine cycle powered by solar energy. In addition, some research interests related to the present study will also be discussed in this paper.

  12. The relationship of air temperature variations over the northern hemisphere during the secular and 11-year solar cycles

    NASA Technical Reports Server (NTRS)

    Ryzhakov, L. Y.; Tomskaya, A. S.

    1978-01-01

    A comparison was made of air temperature anomaly maps for the months of January and July against a background of high and low secular solar activity, with and without regard for the 11 year cycle. By comparing temperature variations during the 11 year and secular cycles, it is found that the 11 year cycle influences thermal conditions more strongly than the secular cycle, and that temperature differences between extreme phases of the solar cycles are greater in January than in July.

  13. The Variation of Solar Fe 14 and Fe 10 Flux over 1.5 Solar Activity Cycles

    NASA Technical Reports Server (NTRS)

    Altrock, Richard C.

    1990-01-01

    A new source of data on the solar output, namely limb flux from the one- and two-million degree corona is presented. This parameter is derived from data obtained at the National Solar Observatory at Sacramento Peak with the 40 cm coronagraph of the John W. Evans Solar Facility and the Emission Line Coronal Photometer. The limb flux is defined to be the latitude-averaged intensity in millionths of the brightness of disk center from an annulus of width 1.1 minutes centered at a height of 0.15 solar constant above the limb of emission from lines at 6374A (Fe X) or 5303A (Fe XIV). Fe XIV data have been obtained since 1973 and Fe X since 1984. Examination of the Fe XIV data shows that there is ambiguity in the definition of the last two solar activity minima, which can affect the determination of cycle rise times and lengths. There is an indication that a constant minimum or basal corona may exist at solar minimum. Cycle 22 has had a much faster onset than Cycle 21 and has now overtaken Cycle 21. The rise characteristics of the two cycles were very similar up until Jul. to Aug. 1989, at which time a long-term maximum occurred in Fe X and Fe XIV, which could possibly be the solar maximum. Another maximum is developing at the current time. Cycle 21 was characterized in Fe XIV by at least 4 major thrusts or bursts of activity, each lasting on the order of a year and all having similar maximum limb fluxes which indicates that coronal energy output is sustained over periods in which the sunspot number declines significantly. Dramatic increases in the limb fluxes occur from minimum to maximum, ranging from factors of 14 to 21 in the two lines. Two different techniques to predict the epoch of solar maximum have been applied to the Fe XIV data, resulting in estimates of April 1989 (plus or minus 1 mo) and May 1990 (plus or minus 2 mos).

  14. Cosmic rays, conditions in interplanetary space and geomagnetic variations during solar cycles 19-24

    NASA Astrophysics Data System (ADS)

    Biktash, Lilia

    2016-07-01

    We have studied conditions in interplanetary space, which can have an influence on galactic and solar cosmic rays (CRs). In this connection the solar wind and interplanetary magnetic field parameters and CRs variations have been compared with geomagnetic activity represented by the equatorial Dst and Kp indices beginning from 1955 to the end 2015. The indices are in common practice in the solar wind-magnetosphere-ionosphere interaction studies and they are the final product of this interaction. The important drivers in interplanetary medium which have effect on cosmic rays as CMEs (coronal mass ejections) and CIRs (corotating interaction regions) undergo very strong changes during their propagation to the Earth. Correlation of sunspot numbers and long-term variations of cosmic rays do not adequately reflect peculiarities concerned with the solar wind arrival to 1 AU also. Moreover records of in situ space measurements of the IMF and most other indicators of solar activity cover only a few decades and have a lot of gaps for calculations of long-term variations. Because of this, in such investigations, the geomagnetic indices have some inestimable advantage as continuous series other the solar wind measurements. We have compared the yearly average variations of the indices and of the solar wind parameters with cosmic ray data from Moscow, Climax, Halekala and Oulu neutron monitors during the 20-24 solar cycles. During the descending phases of the solar cycles the long-lasting solar wind high speed streams occurred frequently and were the primary contributors to the recurrent Dst variations and had effects on cosmic rays variations. We show that long-term Dst and Kp variations in these solar cycles were correlated with cosmic ray count rates and can be used for prediction of CR variations. Climate change in connection with evolution of CRs variations is discussed.

  15. Spectral analysis of auroral geomagnetic activity during various solar cycles between 1960 and 2014

    NASA Astrophysics Data System (ADS)

    Kotzé, Pieter Benjamin

    2016-12-01

    In this paper we use wavelets and Lomb-Scargle spectral analysis techniques to investigate the changing pattern of the different harmonics of the 27-day solar rotation period of the AE (auroral electrojet) index during various phases of different solar cycles between 1960 and 2014. Previous investigations have revealed that the solar minimum of cycles 23-24 exhibited strong 13.5- and 9.0-day recurrence in geomagnetic data in comparison to the usual dominant 27.0-day synodic solar rotation period. Daily mean AE indices are utilized to show how several harmonics of the 27-day recurrent period change during every solar cycle subject to a 95 % confidence rule by performing a wavelet analysis of each individual year's AE indices. Results show that particularly during the solar minimum of 23-24 during 2008 the 27-day period is no longer detectable above the 95 % confidence level. During this interval geomagnetic activity is now dominated by the second (13.5-day) and third (9.0-day) harmonics. A Pearson correlation analysis between AE and various spherical harmonic coefficients describing the solar magnetic field during each Carrington rotation period confirms that the solar dynamo has been dominated by an unusual combination of sectorial harmonic structure during 23-24, which can be responsible for the observed anomalously low solar activity. These findings clearly show that, during the unusual low-activity interval of 2008, auroral geomagnetic activity was predominantly driven by high-speed solar wind streams originating from multiple low-latitude coronal holes distributed at regular solar longitude intervals.

  16. [Mortality in Nuremberg in the 19th century (about 1800 to 1913)].

    PubMed

    Vasold, Manfred

    2006-01-01

    Before the middle of the 19th century urban life was hazardous, life expectancy in big cities was shorter than in the countryside, it was half as high as it is today. Cities used to be called "the graves of mankind"; they were unhygienic, since their inhabitants lived under crowded, unhealthy conditions. In German cities infant mortality was extremely high, one out of three new-born children died within its first year. In most big cities more people died in any given year than were born. In 1806, when the Imperial City of Nuremberg was absorbed by the Kingdom of Bavaria, it had 25 000 inhabitants, fewer than around the year 1600. In the following decades Nuremberg grew quickly, up to 50000 in 1846 and 100000 in 1881, 330000 in 1910. Its population was living extremely crowded within the medieval city-walls, up to 58 000 (1885) in the old parts of the city, more than twice as many as in 1806. Mortality was bound to increase, as more and more people moved to Nuremberg. Mortality rose from 25.5 per thousand in the 1820's to 29.4 in the 1850's and 32.8 in the 1860's. This increase of population was mainly due to migration from outside, from the countryside. New industries settled down in Nuremberg and provided new jobs, the new factories produced lots of smoke and dangerous dust. The general living conditions of the workers were poor, people were much smaller than nowadays. During the industrialisation labor was backbreaking, working hours were extremely long, and annual working hours were more than twice as long as today. New and better legislation was written by the Northern German Confederation, founded in 1867. Now the magistrate of Nuremberg recognised that something had to be done. In the following years physicians began to collect information as to morbidity and mortality in various parts of Nuremberg. Very many people still died of infectious diseases, esp. of tubercolosis, typhoid fever, diphtheria, pertussis, scarlet fever and other infectious diseases. There

  17. Solar Wind Sources in the Late Declining Phase of Cycle 23: Effects of the Weak Solar Polar Field on High Speed Streams

    DTIC Science & Technology

    2009-01-01

    solar wind model (Arge and Pizzo, 2000), based on daily updating solar magnetic field synoptic maps, is then used to map the outflows from the corona ...worldwide. University of California Peer Reviewed Title: Solar Wind Sources in the Late Declining Phase of Cycle 23: Effects of the Weak Solar Polar...currently valid OMB control number. 1. REPORT DATE 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Solar Wind

  18. Geomagnetic activity during 10 - 11 solar cycles that has been observed by old Russian observatories.

    NASA Astrophysics Data System (ADS)

    Seredyn, Tomasz; Wysokinski, Arkadiusz; Kobylinski, Zbigniew; Bialy, Jerzy

    2016-07-01

    A good knowledge of solar-terrestrial relations during past solar activity cycles could give the appropriate tools for a correct space weather forecast. The paper focuses on the analysis of the historical collections of the ground based magnetic observations and their operational indices from the period of two sunspot solar cycles 10 - 11, period 1856 - 1878 (Bartels rotations 324 - 635). We use hourly observations of H and D geomagnetic field components registered at Russian stations: St. Petersburg - Pavlovsk, Barnaul, Ekaterinburg, Nertshinsk, Sitka, and compare them to the data obtained from the Helsinki observatory. We compare directly these records and also calculated from the data of the every above mentioned station IHV indices introduced by Svalgaard (2003), which have been used for further comparisons in epochs of assumed different polarity of the heliospheric magnetic field. We used also local index C9 derived by Zosimovich (1981) from St. Petersburg - Pavlovsk data. Solar activity is represented by sunspot numbers. The correlative and continuous wavelet analyses are applied for estimation of the correctness of records from different magnetic stations. We have specially regard to magnetic storms in the investigated period and the special Carrington event of 1-2 Sep 1859. Generally studied magnetic time series correctly show variability of the geomagnetic activity. Geomagnetic activity presents some delay in relation to solar one as it is seen especially during descending and minimum phase of the even 11-year cycle. This pattern looks similarly in the case of 16 - 17 solar cycles.

  19. The global August 11, 1999 eclipse corona and solar cycle variations

    NASA Astrophysics Data System (ADS)

    Adjabshirizadeh, Ali; Koutchmy, Serge

    2002-03-01

    Qualitative results from the last solar total eclipse (August 11th, 1999) are presented in order to extract some quantitative parameters permitting to discuss the structure of the near-maximum corona and insert the results among what is known of the changing with the solar cycle of activity structure. The collaborative study of the solar corona has been performed in Iran, using a radial gradient filter in white light and other techniques. From the eclipse-processed pictures, a structural drawing was analysed to give the distribution of streamlines over the entire corona, in order to look at the deviations from the local radial direction of identified coronal streamers. From the deduced parameter and the known solar cycle variations of this instantaneous "average deviation" of coronal streamers, as deduced from eclipse observations of 4 preceding cycles, we correctly predicted the moment of the following maximum of activity. We further discuss the method, using the "average deviations" measured in 1996 - 2001 from the Lasco C2 coronagraph processed images (from NRL) of SoHO and found an excellent agreement with the parameters deduced from the last total eclipses of 1998, 1999 and 2001. We believe that "average deviations" are a good parameter to contribute in the understanding of the origin of solar cycle variations of the solar wind and of the magnetic field.

  20. MAGNETIC FLUX CONSERVATION IN THE HELIOSHEATH INCLUDING SOLAR CYCLE VARIATIONS OF MAGNETIC FIELD INTENSITY

    SciTech Connect

    Michael, A. T.; Opher, M.; Provornikova, E.; Richardson, J. D.; Tóth, G. E-mail: mopher@bu.edu E-mail: jdr@space.mit.edu

    2015-04-10

    In the heliosheath (HS), Voyager 2 has observed a flow with constant radial velocity and magnetic flux conservation. Voyager 1, however, has observed a decrease in the flow’s radial velocity and an order of magnitude decrease in magnetic flux. We investigate the role of the 11 yr solar cycle variation of the magnetic field strength on the magnetic flux within the HS using a global 3D magnetohydrodynamic model of the heliosphere. We use time and latitude-dependent solar wind velocity and density inferred from Solar and Heliospheric Observatory/SWAN and interplanetary scintillations data and implemented solar cycle variations of the magnetic field derived from 27 day averages of the field magnitude average of the magnetic field at 1 AU from the OMNI database. With the inclusion of the solar cycle time-dependent magnetic field intensity, the model matches the observed intensity of the magnetic field in the HS along both Voyager 1 and 2. This is a significant improvement from the same model without magnetic field solar cycle variations, which was over a factor of two larger. The model accurately predicts the radial velocity observed by Voyager 2; however, the model predicts a flow speed ∼100 km s{sup −1} larger than that derived from LECP measurements at Voyager 1. In the model, magnetic flux is conserved along both Voyager trajectories, contrary to observations. This implies that the solar cycle variations in solar wind magnetic field observed at 1 AU does not cause the order of magnitude decrease in magnetic flux observed in the Voyager 1 data.

  1. Closed Cycle Engine Program Used in Solar Dynamic Power Testing Effort

    NASA Technical Reports Server (NTRS)

    Ensworth, Clint B., III; McKissock, David B.

    1998-01-01

    NASA Lewis Research Center is testing the world's first integrated solar dynamic power system in a simulated space environment. This system converts solar thermal energy into electrical energy by using a closed-cycle gas turbine and alternator. A NASA-developed analysis code called the Closed Cycle Engine Program (CCEP) has been used for both pretest predictions and post-test analysis of system performance. The solar dynamic power system has a reflective concentrator that focuses solar thermal energy into a cavity receiver. The receiver is a heat exchanger that transfers the thermal power to a working fluid, an inert gas mixture of helium and xenon. The receiver also uses a phase-change material to store the thermal energy so that the system can continue producing power when there is no solar input power, such as when an Earth-orbiting satellite is in eclipse. The system uses a recuperated closed Brayton cycle to convert thermal power to mechanical power. Heated gas from the receiver expands through a turbine that turns an alternator and a compressor. The system also includes a gas cooler and a radiator, which reject waste cycle heat, and a recuperator, a gas-to-gas heat exchanger that improves cycle efficiency by recovering thermal energy.

  2. Polar Chromospheric Signatures of the Subdued Cycle 23/24 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Yashiro, S.; Makela, P.; Shibasaki, K.; Hathaway, D.

    2010-01-01

    Coronal holes appear brighter than the quiet Sun in microwave images, with a brightness enhancement of 500 to 2000 K. The brightness enhancement corresponds to the upper chromosphere, where the plasma temperature is about 10000 K. We constructed a microwave butterfly diagram using the synoptic images obtained by the Nobeyama radioheliograph (NoRH) showing the evolution of the polar and low latitude brightness temperature. While the polar brightness reveals the chromospheric conditions, the low latitude brightness is attributed to active regions in the corona. When we compared the microwave butterfly diagram with the magnetic butterfly diagram, we found a good correlation between the microwave brightness enhancement and the polar field strength. The microwave butterfly diagram covers part of solar cycle 22, whole of cycle 23, and part of cycle 24, thus enabling comparison between the cycle 23/24 and cycle 22/23 minima. The microwave brightness during the cycle 23/24 minimum was found to be lower than that during the cycle 22/23 minimum by approximately 250 K. The reduced brightness temperature is consistent with the reduced polar field strength during the cycle 23/24 minimum seen in the magnetic butterfly diagram. We suggest that the microwave brightness at the solar poles is a good indicator of the speed of the solar wind sampled by Ulysses at high latitudes.

  3. Chromospheric Signatures of the Subdued Cycle 23/24 Solar Minimum in Microwaves

    NASA Technical Reports Server (NTRS)

    Yashiro, S.; Makela, P.; Shibasaki, K.; Hathaway, D.

    2011-01-01

    Coronal holes appear brighter than the quiet Sun in microwave images, with a brightness enhancement of 500 to 2000 K. The brightness enhancement corresponds to the upper chromosphere, where the plasma temperature is about 10000 K. We constructed a microwave butterfly diagram using the synoptic images obtained by the Nobeyama radio-heliograph (NoRH) showing the evolution of the polar and low latitude brightness temperature. While the polar brightness reveals the chromospheric conditions, the low latitude brightness is attributed to active regions in the corona. When we compared the microwave butterfly diagram with the magnetic butterfly diagram, we found a good correlation between the microwave brightness enhancement and the polar field strength. The microwave butterfly diagram covers part of solar cycle 22, whole of cycle 23, and part of cycle 24, thus enabling comparison between the cycle 23/24 and cycle 22/23 minima. The microwave brightness during the cycle 23/24 minimum was found to be lower than that during the cycle 22/23 minimum by approx.250 K. The reduced brightness temperature is consistent with the reduced polar field strength during the cycle 23/24 minimum seen in the magnetic butterfly diagram. We suggest that the microwave brightness at the solar poles is a good indicator of the speed of the solar wind sampled by Ulysses at high latitudes.

  4. Revisiting the prediction of solar activity based on the relationship between the solar maximum amplitude and max-max cycle length

    NASA Astrophysics Data System (ADS)

    Carrasco, V. M. S.; Vaquero, J. M.; Gallego, M. C.

    2017-01-01

    It is very important to forecast the future solar activity due to its effect on our planet and near space. Here, we employ the new version of the sunspot number index (version 2) to analyse the relationship between the solar maximum amplitude and max-max cycle length proposed by Du (2006). We show that the correlation between the parameters used by Du (2006) for the prediction of the sunspot number (amplitude of the cycle, Rm, and max-max cycle length for two solar cycles before, Pmax-2) disappears when we use solar cycles prior to solar cycle 9. We conclude that the correlation between these parameters depends on the time interval selected. Thus, the proposal of Du (2006) should definitively not be considered for prediction purposes.

  5. Solar Wind Helium Abundance as a Function of Speed and Heliographic Latitude: Variation through a Solar Cycle

    NASA Technical Reports Server (NTRS)

    Kasper, J. C.; Stenens, M. L.; Stevens, M. L.; Lazarus, A. J.; Steinberg, J. T.; Ogilvie, Keith W.

    2006-01-01

    We present a study of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind speed and heliographic latitude over the previous solar cycle. The average values of A(sub He), the ratio of helium to hydrogen number densities, are calculated in 25 speed intervals over 27-day Carrington rotations using Faraday Cup observations from the Wind spacecraft between 1995 and 2005. The higher speed and time resolution of this study compared to an earlier work with the Wind observations has led to the discovery of three new aspects of A(sub He), modulation during solar minimum from mid-1995 to mid-1997. First, we find that for solar wind speeds between 350 and 415 km/s, A(sub He), varies with a clear six-month periodicity, with a minimum value at the heliographic equatorial plane and a typical gradient of 0.01 per degree in latitude. For the slow wind this is a 30% effect. We suggest that the latitudinal gradient may be due to an additional dependence of coronal proton flux on coronal field strength or the stability of coronal loops. Second, once the gradient is subtracted, we find that A(sub He), is a remarkably linear function of solar wind speed. Finally, we identify a vanishing speed, at which A(sub He), is zero, is 259 km/s and note that this speed corresponds to the minimum solar wind speed observed at one AU. The vanishing speed may be related to previous theoretical work in which enhancements of coronal helium lead to stagnation of the escaping proton flux. During solar maximum the A(sub He), dependences on speed and latitude disappear, and we interpret this as evidence of two source regions for slow solar wind in the ecliptic plane, one being the solar minimum streamer belt and the other likely being active regions.

  6. The SSRT in the 23rd Cycle of Solar Activity

    NASA Astrophysics Data System (ADS)

    Zandanov, V. G.; Altyntsev, A. T.; Lesovoi, S. V.

    1999-12-01

    We present a sketch of the project to upgrade the Siberian Solar Radio Telescope. We suggest expanding the spectral range of receiving frequencies from a single frequency (5.7~GHz) to five frequencies and to considerably improve the sensitivity of instrument.

  7. QUANTIFYING THE ANISOTROPY AND SOLAR CYCLE DEPENDENCE OF '1/f' SOLAR WIND FLUCTUATIONS OBSERVED BY ADVANCED COMPOSITION EXPLORER

    SciTech Connect

    Nicol, R. M.; Chapman, S. C.; Dendy, R. O.

    2009-10-01

    The power spectrum of the evolving solar wind shows evidence of a spectral break between an inertial range (IR) of turbulent fluctuations at higher frequencies and a '1/f' like region at lower frequencies. In the ecliptic plane at approx1 AU, this break occurs approximately at timescales of a few hours and is observed in the power spectra of components of velocity and magnetic field. The '1/f' energy range is of more direct coronal origin than the IR, and carries signatures of the complex magnetic field structure of the solar corona, and of footpoint stirring in the solar photosphere. To quantify the scaling properties we use generic statistical methods such as generalized structure functions and probability density functions (PDFs), focusing on solar cycle dependence and on anisotropy with respect to the background magnetic field. We present structure function analysis of magnetic and velocity field fluctuations, using a novel technique to decompose the fluctuations into directions parallel and perpendicular to the mean local background magnetic field. Whilst the magnetic field is close to '1/f', we show that the velocity field is '1/f {sup {alpha}}' with {alpha} {ne} 1. For the velocity, the value of {alpha} varies between parallel and perpendicular fluctuations and with the solar cycle. There is also variation in {alpha} with solar wind speed. We have examined the PDFs in the fast, quiet solar wind and intriguingly, whilst parallel and perpendicular are distinct, both the B field and velocity show the same PDF of their perpendicular fluctuations, which is close to {gamma} or inverse Gumbel. These results point to distinct physical processes in the corona and to their mapping out into the solar wind. The scaling exponents obtained constrain the models for these processes.

  8. SUN-LIKE MAGNETIC CYCLES IN THE RAPIDLY ROTATING YOUNG SOLAR ANALOG HD 30495

    SciTech Connect

    Egeland, Ricky; Metcalfe, Travis S.; Hall, Jeffrey C.; Henry, Gregory W.

    2015-10-10

    A growing body of evidence suggests that multiple dynamo mechanisms can drive magnetic variability on different timescales, not only in the Sun but also in other stars. Many solar activity proxies exhibit a quasi-biennial (∼2 year) variation, which is superimposed upon the dominant 11 year cycle. A well-characterized stellar sample suggests at least two different relationships between rotation period and cycle period, with some stars exhibiting long and short cycles simultaneously. Within this sample, the solar cycle periods are typical of a more rapidly rotating star, implying that the Sun might be in a transitional state or that it has an unusual evolutionary history. In this work, we present new and archival observations of dual magnetic cycles in the young solar analog HD 30495, a ∼1 Gyr old G1.5 V star with a rotation period near 11 days. This star falls squarely on the relationships established by the broader stellar sample, with short-period variations at ∼1.7 years and a long cycle of ∼12 years. We measure three individual long-period cycles and find durations ranging from 9.6 to 15.5 years. We find the short-term variability to be intermittent, but present throughout the majority of the time series, though its occurrence and amplitude are uncorrelated with the longer cycle. These essentially solar-like variations occur in a Sun-like star with more rapid rotation, though surface differential rotation measurements leave open the possibility of a solar equivalence.

  9. Sun-like Magnetic Cycles in the Rapidly-rotating Young Solar Analog HD 30495

    NASA Astrophysics Data System (ADS)

    Egeland, Ricky; Metcalfe, Travis S.; Hall, Jeffrey C.; Henry, Gregory W.

    2015-10-01

    A growing body of evidence suggests that multiple dynamo mechanisms can drive magnetic variability on different timescales, not only in the Sun but also in other stars. Many solar activity proxies exhibit a quasi-biennial (∼2 year) variation, which is superimposed upon the dominant 11 year cycle. A well-characterized stellar sample suggests at least two different relationships between rotation period and cycle period, with some stars exhibiting long and short cycles simultaneously. Within this sample, the solar cycle periods are typical of a more rapidly rotating star, implying that the Sun might be in a transitional state or that it has an unusual evolutionary history. In this work, we present new and archival observations of dual magnetic cycles in the young solar analog HD 30495, a ∼1 Gyr old G1.5 V star with a rotation period near 11 days. This star falls squarely on the relationships established by the broader stellar sample, with short-period variations at ∼1.7 years and a long cycle of ∼12 years. We measure three individual long-period cycles and find durations ranging from 9.6 to 15.5 years. We find the short-term variability to be intermittent, but present throughout the majority of the time series, though its occurrence and amplitude are uncorrelated with the longer cycle. These essentially solar-like variations occur in a Sun-like star with more rapid rotation, though surface differential rotation measurements leave open the possibility of a solar equivalence.

  10. Solar cycle variation of some mass dependent characteristics of upflowing beams of terrestrial ions

    NASA Technical Reports Server (NTRS)

    Collin, H. L.; Peterson, W. K.; Shelley, E. G.

    1987-01-01

    Examination of the S3-3 and DE ion composition data spread over a solar cycle indicates that some characteristics of energetic upflowing terrestrial ion beams above the auroral zone show dependence on solar cycle. At solar maximum the different ion beam mass components have comparable mean energies, and O(+) dominates the beam composition. The ion energies are consistent with having been acquired from the potential drop below the satellite inferred from the electron loss cone distributions. At solar minimum the beam composition is dominated by H(+), but the O(+) has a higher mean energy and is hotter than the H(+) component. Also, the O(+) has more energy than it could itself have acquired from the potential drop. These observations are qualitatively consistent with the ion beams having acquired their energies from a parallel electric field and being partially thermalized through the two-stream instability between the two ion species, with this effect being modulated by the beam composition.

  11. Equatorial thermospheric wind changes during the solar cycle - Measurements at Arequipa, Peru, from 1983 to 1990

    NASA Technical Reports Server (NTRS)

    Biondi, M. A.; Meriwether, J. W., Jr.; Fejer, B. G.; Gonzalez, S. A.; Hallenbeck, D. C.

    1991-01-01

    Near-equatorial thermospheric wind velocities at Arequipa, Peru, are determined over about two-thirds of a solar cycle using Fabry-Perot interferometer measurements of Doppler shifts in the nightglow 630-nm emission line. Mean monthly nocturnal variations in the meridional and zonal wind components are calculated from the nightly data to remove short-term (day-to-day) variability as well as any additional changes introduced by the progression of the solar cycle. For most of the years, at the winter solstice, there is a weak (more than 100 m/s) transequatorial flow from the summer to the winter hemisphere in the early and the late night, with essentially zero velocities in between. At the equinoxes, an early-night poleward (southward) flow at solar minimum (1986) is replaced by an equatorward (northward) flow at solar maximum (1989-1990).

  12. The Waldmeier rule and early diagnostics of the maximum of the current solar cycle

    NASA Astrophysics Data System (ADS)

    Nagovitsyn, Yu. A.; Kuleshova, A. I.

    2012-10-01

    The well known Waldmeier rule and its modifications applied to forecasting of the solar activity are discussed. The maximum annual mean rate of the increase in the magnetic flux observed on the growth branch of the cycle is proposed as a predicting (diagnosing) parameter for the amplitude of the cycle currently in progress. The maximum Wolf number of the current (24th) cycle is estimated to reach 104 (±12) or more, and to occur in 2013 or later. The yearly average Wolf numbers observed during the 24th cycle are presented.

  13. Comparing the Large-Scale Magnetic Field During the Last Three Solar Cycles (Invited)

    NASA Astrophysics Data System (ADS)

    Hoeksema, J. T.

    2009-12-01

    Large-scale magnetic field observations show that the current extended solar cycle minimum differs from the two previous well-observed minima in several respects. The weaker polar fields increase the relative influence of middle and low-latitude flux patterns on the configuration of the corona and heliosphere. A much larger fraction of the open flux originates in equatorial coronal holes. Even though the heliospheric field magnitude and the mean solar magnetic field are the weakest since direct measurements began, the sector structure of the interplanetary field that reflects the shape of the heliospheric current sheet continues to extend to fairly high latitude. The pattern of emergence of active regions through the cycle and the transport of flux from low to high latitudes also show quite different patterns, providing insight into the meridional flow that influences the dynamo that drives the cycle. The long records of synoptic observations that provide a rich source of information about solar activity must be maintained.

  14. Computer modeling of a regenerative solar-assisted Rankine power cycle

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.

    1977-01-01

    A detailed interpretation of the computer program that describes the performance of one of these cycles; namely, a regenerative Rankine power cycle is presented. Water is used as the working medium throughout the cycle. The solar energy collected at relatively low temperature level presents 75 to 80% of the total heat demand and provides mainly the latent heat of vaporization. Another energy source at high temperature level superheats the steam and supplements the solar energy share. A program summary and a numerical example showing the sequency of computations are included. The outcome from the model comprises line temperatures, component heat rates, specific steam consumption, percentage of solar energy contribution, and the overall thermal efficiency.

  15. Coronal mass ejections and solar wind mass fluxes over the heliosphere during solar cycles 23 and 24 (1996-2014)

    NASA Astrophysics Data System (ADS)

    Lamy, P.; Floyd, O.; Quémerais, E.; Boclet, B.; Ferron, S.

    2017-01-01

    Coronal mass ejections (CMEs) play a major role in the heliosphere, and their contribution to the solar wind mass flux, already considered in the Skylab and Solwind eras with conflicting results, is reexamined in the light of 19 years (1996-2014) of SOHO observations with the Large Angle and Spectroscopic Coronagraph (LASCO-C2) for the CMEs and extended for the first time to all latitudes thanks to the whole-heliosphere data from the Solar Wind ANisotropies (SWAN) instrument supplemented by in situ data aggregated in the OMNI database. First, several mass estimates reported in the ARTEMIS (Automated Recognition of Transient Events and Marseille Inventory from Synoptic maps) catalog of LASCO CMEs are compared with determinations based on the combined observations with the twin STEREO/Sun Earth Connection Coronal and Heliospheric Investigation coronagraphs in order to ascertain their validity. A simple geometric model of the CMEs is introduced to generate Carrington maps of their mass flux and then to produce annualized synoptic maps. The Lyman α SWAN data are inverted to similarly produce synoptic maps to be compared with those of the CME flux. The ratio of the annualized CME to solar wind mass flux is found to closely track the solar cycle over the heliosphere. In the near-ecliptic region and at latitudes up to ˜55°, this ratio was negligibly small during the solar minima of cycles 22/23 and 23/24 and rose to 6% and 5%, respectively, at the maximum of solar cycles 23 and 24. These maximum ratios increased at higher latitudes, but this result is likely biased by the inherent limitation of determining the true latitude of CMEs.

  16. On Ideas as Actors: How Ideas about Yellow Fever Causality Shaped Public Health Policy Responses in 19th-Century Galveston.

    PubMed

    Goldberg, Daniel S

    2012-01-01

    This article uses debates regarding yellow fever causality among leading healers in 19th-century Galveston, Texas, U.S., as a means of exploring the extent to which ideas are social actors. That is, the analysis demonstrates that ideas about yellow fever causality shaped contemporaneous public health policy responses to yellow fever outbreaks in 19th-century Galveston. The article contributes to the growing literature documenting that contagionist and anticontagionist views were often assimilated, and also supports the historiography showing that the predisposing/exciting causes dichotomy is a more robust intellectual framework for understanding 19th-century attributions of disease causality.

  17. Using the 11-year Solar Cycle to Predict the Heliosheath Environment at Voyager 1 and 2

    NASA Astrophysics Data System (ADS)

    Michael, A.; Opher, M.; Provornikova, E.; Richardson, J. D.; Toth, G.

    2015-12-01

    As Voyager 2 moves further into the heliosheath, the region of subsonic solar wind plasma in between the termination shock and the heliopause, it has observed an increase of the magnetic field strength to large values, all while maintaining magnetic flux conservation. Dr. Burlaga will present these observations in the 2015 AGU Fall meeting (abstract ID: 59200). The increase in magnetic field strength could be a signature of Voyager 2 approaching the heliopause or, possibly, due to solar cycle effects. In this work we investigate the role the 11-year solar cycle variations as well as magnetic dissipation effects have on the heliosheath environments observed at Voyager 1 and 2 using a global 3D magnetohydrodynamic model of the heliosphere. We use time and latitude-dependent solar wind velocity and density inferred from SOHO/SWAN and IPS data and solar cycle variations of the magnetic field derived from 27-day averages of the field magnitude average of the magnetic field at 1 AU from the OMNI database as presented in Michael et al. (2015). Since the model has already accurately matched the flows and magnetic field strength at Voyager 2 until 93 AU, we extend the boundary conditions to model the heliosheath up until Voyager 2 reaches the heliopause. This work will help clarify if the magnetic field observed at Voyager 2 should increase or decrease due to the solar cycle. We describe the solar magnetic field both as a dipole, with the magnetic and rotational axes aligned, and as a monopole, with magnetic field aligned with the interstellar medium to reduce numerical reconnection within the heliosheath, due to the removal of the heliospheric surrent sheet, and at the solar wind - interstellar medium interface. A comparison of the models allows for a crude estimation of the role that magnetic dissipation plays in the system and whether it allows for a better understanding of the Voyager 2 location in the heliosheath.

  18. The Effect of CMEs on Heliospheric Structure during the Ascending Phase of Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Webb, D. F.

    2013-12-01

    The frequency of occurrence of CMEs observed in white light (WL) tends to track the solar cycle in both phase and amplitude, which varies by an order of magnitude over the cycle. Since WL CMEs have been counted since Skylab in the 1970s, we now have observations extending over the last four solar cycles. LASCO has now observed the entire Cycle 23 and continues to observe through the current rise to maximum of Cycle 24. It has detected CMEs at a rate slightly higher than earlier observations, varying from ~0.3/day around solar minimum to ~4/day at maximum. Running averages of the CME rate vs. sunspot number show that both have double cycle peaks, with the CME peak lagging sunspots by many months. This lag is likely related to observations that high latitude CMEs arise from polar crown filaments which have a 'rush to the poles'' near maximum and disappear (erupt) with a frequency that slightly lags sunspot numbers at low latitudes. Cycle 23 had an unusually long decline and flat minimum. Since 2006 we have been able to image and count CMEs in the heliosphere, and can determine rates from both LASCO and STEREO coronagraphs and from the Solar Mass Ejection Imager (SMEI) and the SECCHI Heliospheric Imagers in the heliosphere. Manual rates estimated by observers are now supplemented by counts from identifications made by automatic programs, such as in the SEEDS, CACTus and ARTEMIS catalogs. There is some indication that the CME rate is diverging somewhat from the sunspot number since about 2010. We will discuss these rate estimates, both for the Cycle 23-24 period and over the last four cycles for which we have WL CME observations.

  19. Advances in understanding the genesis and evolution solar energetic particle events over the last two solar cycles

    NASA Astrophysics Data System (ADS)

    Vainio, Rami

    2016-04-01

    I will review the observational and modeling efforts related to solar energetic particle (SEP) events over the 23rd and 24th solar cycles. I will concentrate on large SEP events related to coronal mass ejections (CMEs), but discuss observations related to the possible role of flares in the acceleration of particles in those events, as well. The possible roles of various acceleration and transport processes in understanding the characteristics of the events will be discussed. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA).

  20. Effects of Stratospheric Ozone Depletion, Solar UV Radiation, and Climate Change on Biogeochemical Cycling: Interactions and Feedbacks

    EPA Science Inventory

    Climate change modulates the effects of solar UV radiation on biogeochemical cycles in terrestrial and aquatic ecosystems, particularly for carbon cycling, resulting in UV-mediated positive or negative feedbacks on climate. Possible positive feedbacks discussed in this assessment...

  1. Low Cost Solar Energy Conversion (Carbon Cycle 2.0)

    ScienceCinema

    Ramesh, Ramamoorthy

    2016-07-12

    Ramamoorthy Ramesh from LBNL's Materials Science Division speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  2. Influence of geomagnetic activity and atmospheric pressure on human arterial pressure during the solar cycle 24

    NASA Astrophysics Data System (ADS)

    Azcárate, T.; Mendoza, B.; Levi, J. R.

    2016-11-01

    We performed a study of the systolic (SBP) and diastolic (DBP) arterial blood pressure behavior under natural variables such as the atmospheric pressure (AtmP) and the horizontal geomagnetic field component (H). We worked with a sample of 304 healthy normotense volunteers, 152 men and 152 women, with ages between 18 and 84 years in Mexico City during the period 2008-2014, corresponding to the minimum, ascending and maximum phases of the solar cycle 24. The data was divided by gender, age and day/night cycle. We studied the time series using three methods: Correlations, bivariate and superposed epochs (within a window of three days around the day of occurrence of a geomagnetic storm) analysis, between the SBP and DBP and the natural variables (AtmP and H). The correlation analysis indicated correlation between the SBP and DBP and AtmP and H, being the largest during the night. Furthermore, the correlation and bivariate analysis showed that the largest correlations are between the SBP and DBP and the AtmP. The superposed epoch analysis found that the largest number of significant SBP and DBP changes occurred for women. Finally, the blood pressure changes are larger during the solar minimum and ascending solar cycle phases than during the solar maximum; the storms of the minimum were more intense than those of the maximum and this could be the reason of behavior of the blood pressure changes along the solar cycle.

  3. Simulation Study of Hemispheric Phase-Asymmetry in the Solar Cycle

    NASA Astrophysics Data System (ADS)

    Shukuya, D.; Kusano, K.

    2017-01-01

    Observations of the Sun suggest that solar activities systematically create north–south hemispheric asymmetries. For instance, the hemisphere in which sunspot activity is more active tends to switch after the early half of each solar cycle. Svalgaard & Kamide recently pointed out that the time gaps of polar field reversal between the northern and southern hemispheres are simply consequences of the asymmetry of sunspot activity. However, the mechanism underlying the asymmetric feature in solar cycle activity is not yet well understood. In this paper, in order to explain the cause of the asymmetry from the theoretical point of view, we investigate the relationship between the dipole- and quadrupole-type components of the magnetic field in the solar cycle using the mean-field theory based on the flux transport dynamo model. As a result, we found that there are two different attractors of the solar cycle, in which either the north or the south polar field is first reversed, and that the flux transport dynamo model explains well the phase-asymmetry of sunspot activity and the polar field reversal without any ad hoc source of asymmetry.

  4. Solar cycle variations of thermospheric O/N2 longitudinal pattern from TIMED/GUVI

    NASA Astrophysics Data System (ADS)

    Luan, Xiaoli; Wang, Wenbin; Burns, Alan; Dou, Xiankang

    2017-02-01

    Thermospheric composition (O/N2 ratio) is well known to have a great impact on the variation of daytime ionospheric electron density. This study aims to investigate the local time, seasonal, and solar cycle variations of the O/N2 longitudinal pattern in both hemispheres during daytime in solstices. The O/N2 data used are from TIMED/Global Ultraviolet Imager observations made over a solar cycle for geomagnetically quiet conditions. The main findings are as follows: (1) The O/N2 longitudinal patterns are generally similar during 10:00-14:00 LT and between solar minimum and maximum, although the O/N2 values change with local time and solar cycle. (2) The winter O/N2 subauroral enhancement is unexpectedly smaller in the longitudes where the magnetic pole is (near-pole longitudes), rather than in the longitudes far from the magnetic pole, especially during solar maximum, and consequently, the longitudinal pattern of O/N2 depends on latitude in local winter. (3) The winter O/N2 subauroral enhancement generally moves to more poleward latitudes during solar maximum, as compared to solar minimum. (4) At higher midlatitudes ( 45°-60°N and 40°-50°S in geographic latitudes) in solar minimum, the winter-to-summer ratio of O/N2 in each hemisphere has an obvious minimum in near-pole longitudes. This minimum becomes more evident during solar maximum. The National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model simulations indicate that in the winter hemisphere, the unexpected O/N2 longitudinal pattern in higher midlatitudes is mainly associated with high-latitude Joule heating under the impact from ion convection and auroral precipitation.

  5. Solar Cycle Variability in Mean Thermospheric Composition and Temperature Induced by Atmospheric Tides

    NASA Astrophysics Data System (ADS)

    Jones, M., Jr.; Forbes, J. M.; Hagan, M. E.

    2015-12-01

    Vertically-propagating atmospheric thermal tides whose origins lie in Earth's lower atmosphere are now widely recognized as one of the dominant "meteorological" drivers of space weather. Many prior research efforts have focused on documenting and understanding the role that dissipating tides play in determining the longitudinal and seasonal variability associated with lower thermospheric winds, temperature, and constituent densities. However, considerably less attention has focused on understanding the potential solar cycle variability in the mean thermospheric state induced by the tides. In this paper we utilize the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM), forced with observationally-based tides at the model lower boundary from the Climatological Tidal Model of the Thermosphere (CTMT, from Oberheide et al. [2011]), to elucidate how the dissipating tides induce variations of up to 30 K in the zonal-mean thermosphere temperature between solar minimum and maximum. Numerical experiments are performed for the month of September and for solar minimum, medium, and maximum conditions in order to quantify the solar cycle variability associated with the different terms in the thermodynamic energy, major and minor neutral constituent continuity equations. Our analysis indicates that solar cycle variability in neutral temperatures results from a combination of net eddy heat transport effects and tidal modulation of net nitric oxide (NO) cooling. The chemical and dynamical pathways through which dissipating tides affect mean NO cooling differently at solar minimum and maximum are diagnosed.

  6. 100 W-class solar pumped laser for sustainable magnesium-hydrogen energy cycle

    NASA Astrophysics Data System (ADS)

    Yabe, T.; Bagheri, B.; Ohkubo, T.; Uchida, S.; Yoshida, K.; Funatsu, T.; Oishi, T.; Daito, K.; Ishioka, M.; Yasunaga, N.; Sato, Y.; Baasandash, C.; Okamoto, Y.; Yanagitani, K.

    2008-10-01

    A solar pumped laser system with 7%-9% slope efficiencies has been developed. A Fresnel lens (2×2 m, f =2000 mm) is mounted on a two-axis sun tracker platform and focuses solar radiation toward laser cavity, which embraces Cr:Nd:yttrium aluminum garnet ceramic rod. The maximum emitted laser power is 80 W corresponding to maximum total area performance of 20 W/m2 for the Fresnel lens area. This solar laser system would be used as a section of power plant in a magnesium energy cycle as a cost-efficient solar energy converter. Using direct solar radiation into laser, 4.3% net conversion efficiency has been achieved.

  7. Systems analysis techniques for annual cycle thermal energy storage solar systems

    SciTech Connect

    Baylin, F.; Sillman, S.

    1980-07-01

    Community-scale annual cycle thermal energy storage (ACTES) solar systems are promising options for building heat and cooling. A variety of approaches are feasible in modeling ACTES solar systems. The key parameter in such efforts, average collector efficiency, is first examined, followed by several approaches for simple and effective modeling. Methods are also examined for modeling building loads for structures based on both conventional and passive architectural designs. Two simulation models for sizing solar heating systems with annual storage are presented next. Validation is presented by comparison with the results of a study of seasonal storage systems based on SOLANSIM, an hour-by-hour simulation. These models are presently being used to examine the economic trade-off between collector field area and storage capacity. Finally, programs in the US Department of Energy directed toward developing either other system components such as improved tanks and solar ponds or design tools for ACTES solar systems are examined.

  8. THE ACOUSTIC CUTOFF FREQUENCY OF THE SUN AND THE SOLAR MAGNETIC ACTIVITY CYCLE

    SciTech Connect

    Jimenez, A.; Palle, P. L.; Garcia, R. A.

    2011-12-20

    The acoustic cutoff frequency-the highest frequency for acoustic solar eigenmodes-is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but are traveling waves. Interference among them gives rise to higher-frequency peaks-the pseudomodes-in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p-modes, making possible the use of pseudomodes to determine the acoustic cutoff frequency. Using data from the GOLF and VIRGO instruments on board the Solar and Heliospheric Observatory spacecraft, we calculate the acoustic cutoff frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 until the present), a variation in the acoustic cutoff frequency with the solar magnetic activity cycle is found.

  9. Nitrogen, land and water inputs in changing cattle farming systems. A historical comparison for France, 19th-21st centuries.

    PubMed

    Chatzimpiros, Petros; Barles, Sabine

    2010-09-15

    This paper provides an original account of the long-term regional metabolism in relation to the cattle rearing in western France starting by the precise formulation of animal diets at three key dates of the 19th, 20th and 21st centuries. We established links between the demand in fodder of the meat and dairy sectors and the necessary inputs of nitrogen, water and land as well as the land cover changes occurring on the affected local and remote cattle acreage. The average agricultural productivity for fodder supply is estimated at about 50 kg N/ha in the mid-19th, 54 kg N/ha in the early 20th and 150 kg N/ha at the turning of the 21st century. Jointly for the dairy and meat productions, the potential efficiency in the conversion of the vegetal into animal protein more than doubled over the studied period, passing from less than 9% in the 19th to 20% in the 21st century. The current cattle sector is sustained for about 25% by land situated beyond the regional frontiers and uses water at intensities that approach or exceed the availability of renewable water. The nitrogen pollution is expressed in terms of the Net Anthropogenic Nitrogen Inputs (NANI) and, by comparison to the N recovered in products, is used to define the N-Environmental Efficiency of the farming. We discuss the historical succession of the factors that contributed to the growth of the meat and milk production and make a comparison of the impacts and policy between the local and distant resources.

  10. On the changes with solar cycles of cosmic ray propagation parameters and dimension of modulation region and heliosphere

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    We continue our investigations of cosmic ray-solar activity hysteresis phenomenon by using data of Climax and Huancayo/Haleakala neutron monitors and Huancayo ionization chamber for about 4 solar cycles. We determine approximately the changes from one cycle to another of the effective dimension of modulation region and Heliosphere and show that there is a great difference between even and odd solar cycles, and appreciable dependence on the effective rigidity of cosmic ray particles for even cycles. It appears that there are at least 3 cycles in cosmic ray modulation: 11, 22 and 44 years.

  11. Dynamics of the photosphere along the solar cycle from SDO/HMI

    NASA Astrophysics Data System (ADS)

    Roudier, Th.; Malherbe, J. M.; Mirouh, G. M.

    2017-02-01

    Context. As the global magnetic field of the Sun has an activity cycle, one expects to observe some variation of the dynamical properties of the flows visible in the photosphere. Aims: We investigate the flow field during the solar cycle by analysing SDO/HMI observations of continuum intensity, Doppler velocity and longitudinal magnetic field. Methods: We first picked data at disk center during 6 yr along the solar cycle with a 48-h time step in order to study the overall evolution of the continuum intensity and magnetic field. Then we focused on thirty 6-h sequences of quiet regions without any remnant of magnetic activity separated by 6 months, in summer and winter, when disk center latitude B0 is close to zero. The horizontal velocity was derived from the local correlation tracking technique over a field of view of 216.4 Mm × 216.4 Mm located at disk center. Results: Our measurements at disk center show the stability of the flow properties between meso- and supergranular scales along the solar cycle. Conclusions: The network magnetic field, produced locally at disk center independently from large scale dynamo, together with continuum contrast, vertical and horizontal flows, seem to remain constant during the solar cycle.

  12. H-alpha synoptic charts of solar activity during the first year of solar cycle 20, October 1964 - August 1965. [Skylab program

    NASA Technical Reports Server (NTRS)

    Mcintosh, P. S.

    1975-01-01

    Solar activity during the period October 28, 1964 through August 27, 1965 is presented in the form of charts for each solar 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 Solar Cycle 20 occurred in October, 1964; therefore, charts represent solar activity during the first year of this solar cycle.

  13. Life Cycle Assessment of Titania Perovskite Solar Cell Technology for Sustainable Design and Manufacturing.

    PubMed

    Zhang, Jingyi; Gao, Xianfeng; Deng, Yelin; Li, Bingbing; Yuan, Chris

    2015-11-01

    Perovskite solar cells have attracted enormous attention in recent years due to their low cost and superior technical performance. However, the use of toxic metals, such as lead, in the perovskite dye and toxic chemicals in perovskite solar cell manufacturing causes grave concerns for its environmental performance. To understand and facilitate the sustainable development of perovskite solar cell technology from its design to manufacturing, a comprehensive environmental impact assessment has been conducted on titanium dioxide nanotube based perovskite solar cells by using an attributional life cycle assessment approach, from cradle to gate, with manufacturing data from our laboratory-scale experiments and upstream data collected from professional databases and the literature. The results indicate that the perovskite dye is the primary source of environmental impact, associated with 64.77% total embodied energy and 31.38% embodied materials consumption, contributing to more than 50% of the life cycle impact in almost all impact categories, although lead used in the perovskite dye only contributes to about 1.14% of the human toxicity potential. A comparison of perovskite solar cells with commercial silicon and cadmium-tellurium solar cells reveals that perovskite solar cells could be a promising alternative technology for future large-scale industrial applications.

  14. Analysis of 18th-19th century's historical samples of Iranian ink and paper belonging to the Qajar dynasty

    NASA Astrophysics Data System (ADS)

    Agha-Aligol, D.; Khosravi, F.; Lamehi-Rachti, M.; Baghizadeh, A.; Oliaiy, P.; Shokouhi, F.

    2007-11-01

    Thirteen historical Iranian manuscripts belonging to the Qajar dynasty (18th-19th Century BC) were investigated by micro-PIXE technique using Van de Graaff accelerator in the Nuclear Science & Technology Research Institute in Iran. The aim of the present work has mainly been to determine the elemental composition of different inks and papers. In addition, the effects due to the variation of thickness and texture of the paper were simultaneously measured with the off-axis STIM technique. Elemental maps by micro-PIXE were compared to photographs taken in visible light.

  15. Causes of mortality due to rheumatic diseases in Jerez de los Caballeros (Badajoz) during the 19th century.

    PubMed

    Peral Pacheco, Diego; Suárez-Guzmán, Francisco Javier

    2016-01-01

    A total of 26,203 of the deaths in Jerez de los Caballeros (Badajoz) during the 19th century were collected and grouped according to the Bertillon's Classification, in order to study the causes of death from rheumatic diseases. An analysis was made using the Death Registers, those located in the Parish Archives, and files of the Municipal Archives. There were a total of 31 deaths due to rheumatic diseases, with the 65-74 years age group being most frequent. The lack of records may be due to the inaccuracy of the diagnoses. September was the month of increased mortality.

  16. The influence of inequality on the standard of living: worldwide anthropometric evidence from the 19th and 20th centuries.

    PubMed

    Blum, Matthias

    2013-12-01

    We provide empirical evidence on the existence of the Pigou-Dalton principle. The latter indicates that aggregate welfare is - ceteris paribus - maximized when incomes of all individuals are equalized (and therefore marginal utility from income is as well). Using anthropometric panel data on 101 countries during the 19th and 20th centuries, we determine that there is a systematic negative and concave relationship between height inequality and average height. The robustness of this relationship is tested by means of several robustness checks, including two instrument variable regressions. These findings help to elucidate the impact of economic inequality on welfare.

  17. ["The mind-body problem". The relation of psychical to physical in 19th century German psychology].

    PubMed

    Romand, David

    2010-01-01

    During the 19th century, the question of the relation between the soul and the body was dee