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Sample records for 11-year sunspot cycle

  1. Relations of latitudinal characteristics of sunspot groups to the 11-year cycle amplitude at different phases

    NASA Astrophysics Data System (ADS)

    Miletskii, E. V.; Ivanov, V. G.

    2016-12-01

    Using sunspot data for cycles 12 to 23, we have investigated relations of some latitude characteristics of sunspot groups to the 11-year cycle amplitude at different phases. We have revealed a high correlation (with correlation coefficients >0.9) between the middle latitude of sunspot groups at phases of rise, maximum, and decay, on the one hand, and the amplitude of the corresponding cycle, on the other hand. We have shown that the maxima of the velocity of the motion of the sunspot formation zone to the equator have a special physical meaning: the rise phase of the 11-year cycle is characterized by significant correlations between the cycle amplitude and the maximum for the lowest boundary, and the cycle decay phase is characterized by the same maximum for the highest boundary. We have built equations allowing one to determine the amplitude of the 11-year cycle on the basis of data on the given latitudinal characteristics of sunspots groups.

  2. Cosmic Ray 11-Year Modulation for Sunspot Cycle 24

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.; Ygbuhay, R. C.

    2015-02-01

    Galactic cosmic-ray (GCR) modulation at 1 AU for sunspot (SSN) Cycle 24 is studied using data from a global network of detectors and balloon measurements of low-energy ions at high latitudes in Russia. The observed modulation is modest compared with previous cycles. The tilt angle of the heliospheric current sheet reached a maximum value for Cycle 24 even though the peak of the interplanetary magnetic-field intensity at 1 AU has a much lower value (≈ 5 nT). The solar polar field in the northern hemisphere reversed in June 2012 and again in March 2014 while that in the southern hemisphere reversed in July 2013. The double field reversal in northern hemisphere after SSN maximum is not expected from dynamo theory. GCR modulation is at maximum phase in 2013. We have also studied the anomalous GCR recovery in 2009 using data from a low-energy proton channel on Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA). The rigidity dependence of the Cycle 24 modulation is computed using data from neutron monitors, directional muon telescopes at Nagoya, Japan, and detectors on balloons at high latitudes in Russia. It is a power law with an exponent -1.29, similar to previous solar cycles (-1.2±0.1); the nearly linear dependence of the modulation on the rigidity over a wide range poses a challenge to the quasi-linear theory (QLT) of GCR modulation.

  3. The Signal of the 11-Year Sunspot Cycle in the Upper Troposphere-Lower Stratosphere

    NASA Astrophysics Data System (ADS)

    Labitzke, K.; van Loon, H.

    1997-05-01

    The paper summarizes work by the authors over the past ten years on an apparent signal of the 11-year sunspot cycle in the lower stratosphere-upper troposphere. The signal appears as a basic, consistent pattern in correlations between heights of stratospheric constant-pressure levels, at least as high as 25 km, and the solar cycle in which the highest correlations are in the subtropics. The variation of the stratospheric heights in phase with the sunspot cycle are - in the areas of high correlations between the two - associated with temperature variations on the same time scale in the middle and upper troposphere. The spatial distribution of the correlations suggests that the year-to-year changes in tropical and subtropical vertical motions contain a component on the time scale of the solar cycle. In January and February the correlations with the sunspot cycle are smallest. The smallness of the correlations is owing to the fact that they are different in the east and west years of the quasi-biennial oscillation in the equatorial stratospheric winds. The correlation pattern in the east years is the same as in the other seasons and is statistically significant. In the west years the correlations are insignificant outside the arctic, and the positive correlation in the arctic in these years is related to the fact that major midwinter breakdowns of the cyclonic vortex in the west years so far have happened only at maxima in the solar cycle. Until recently reliable continuous series of analyses of the stratosphere were not available for the southern hemisphere. The U.S. National Centers for Environmental Prediction and the National Center for Atmospheric Research have now, however, issued a 23-year series of re-analyzed global data which has made it possible to detect the solar signal on the southern hemisphere. It turns out to be almost the same as that on the northern hemisphere. The correlations between total column ozone and the sunspot cycle are lowest in the

  4. Predicting the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2009-01-01

    The 11-year sunspot cycle was discovered by an amateur astronomer in 1844. Visual and photographic observations of sunspots have been made by both amateurs and professionals over the last 400 years. These observations provide key statistical information about the sunspot cycle that do allow for predictions of future activity. However, sunspots and the sunspot cycle are magnetic in nature. For the last 100 years these magnetic measurements have been acquired and used exclusively by professional astronomers to gain new information about the nature of the solar activity cycle. Recently, magnetic dynamo models have evolved to the stage where they can assimilate past data and provide predictions. With the advent of the Internet and open data policies, amateurs now have equal access to the same data used by professionals and equal opportunities to contribute (but, alas, without pay). This talk will describe some of the more useful prediction techniques and reveal what they say about the intensity of the upcoming sunspot cycle.

  5. Special points in 11-year variations in the latitudinal characteristics of sunspot activity

    NASA Astrophysics Data System (ADS)

    Miletsky, E. V.; Nagovitsyn, Yu. A.

    2012-12-01

    It has been indicated that special moments (turning points), when certain characteristics of the latitudinal (equatorward) drift of the sunspot drift zone suddenly change, exist in each 11-year solar cycle. The moment when a sunspot formation low-latitude boundary minimum (T2), coordinated in time with the end of a polar magnetic field polarity reversal, exists has a special place among these points. A conclusion has been drawn that it is impossible to reconstruct polarity reversal moments in the past based on information about turning points T2. The average velocities of the latitudinal drift of the minimal, average, and maximal sunspot group latitudes have been calculated. It has been indicated that the closeness of the relationship between the first two velocities and the maximal activity amplitudes in the cycles differ substantially for the first (before point T2) and second (after point T2) cycle parts. The corresponding values of the correlation coefficients increase substantially in the second cycle (after point T2). It has been established that a relationship exists between some velocities calculated in these cycles and the activity amplitudes at maximums of the next cycles. A model for predicting future cycle maximums has been constructed based on this conclusion. The probable average annual Wolf number at a maximum of cycle 24 has been determined (W(24) = 93).

  6. Hindcast and forecast of grand solar minina and maxima using a three-frequency dynamo model based on Jupiter-Saturn tidal frequencies modulating the 11-year sunspot cycle

    NASA Astrophysics Data System (ADS)

    Scafetta, Nicola

    2016-04-01

    The Schwabe frequency band of the Zurich sunspot record since 1749 is found to be made of three major cycles with periods of about 9.98, 10.9 and 11.86 years. The two side frequencies appear to be closely related to the spring tidal period of Jupiter and Saturn (range between 9.5 and 10.5 years, and median 9.93 years) and to the tidal sidereal period of Jupiter (about 11.86 years). The central cycle can be associated to a quasi-11-year sunspot solar dynamo cycle that appears to be approximately synchronized to the average of the two planetary frequencies. A simplified harmonic constituent model based on the above two planetary tidal frequencies and on the exact dates of Jupiter and Saturn planetary tidal phases, plus a theoretically deduced 10.87-year central cycle reveals complex quasi-periodic interference/beat patterns. The major beat periods occur at about 115, 61 and 130 years, plus a quasi-millennial large beat cycle around 983 years. These frequencies and other oscillations appear once the model is non-linearly processed. We show that equivalent synchronized cycles are found in cosmogenic records used to reconstruct solar activity and in proxy climate records throughout the Holocene (last 12,000 years) up to now. The quasi-secular beat oscillations hindcast reasonably well the known prolonged periods of low solar activity during the last millennium such as the Oort, Wolf, Sporer, Maunder and Dalton minima, as well as the 17 115-year long oscillations found in a detailed temperature reconstruction of the Northern Hemisphere covering the last 2000 years. The millennial cycle hindcasts equivalent solar and climate cycles for 12,000 years. Finally, the harmonic model herein proposed reconstructs the prolonged solar minima that occurred during 1900- 1920 and 1960-1980 and the secular solar maxima around 1870-1890, 1940-1950 and 1995-2005 and a secular upward trending during the 20th century: this modulated trending agrees well with some solar proxy model, with

  7. Active longitudes in the period of overlap of 11-year cycles

    NASA Astrophysics Data System (ADS)

    Kramynin, A. P.; Mikhalina, F. A.

    2016-12-01

    It is shown that "active longitudes" for the sunspots of old and new cycles manifest themselves approximately in the same longitudinal intervals and remain for several 11-year cycles. To be more accurate, they vanish in some cycles but then appear again at the same longitudinal intervals in the other cycles. The entire period is characterized by a total of four active longitudes. The old-cycle sunspots observed at low equatorial latitudes in the Northern and Southern Hemispheres are characterized by a shift by ≈180°, which indicates antipodality of the active longitudes in the Northern and Southern Hemispheres. In the case of highlatitude sunspots (new-cycle sunspots), the best correlation is observed for the shift of ≈90°. There is supposedly a dependence of the rotation speed of active longitudes on the secular cycle.

  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. An Examination of Sunspot Number Rates of Growth and Decay in Relation to the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    On the basis of annual sunspot number averages, sunspot number rates of growth and decay are examined relative to both minimum and maximum amplitudes and the time of their occurrences using cycles 12 through present, the most reliably determined sunspot cycles. Indeed, strong correlations are found for predicting the minimum and maximum amplitudes and the time of their occurrences years in advance. As applied to predicting sunspot minimum for cycle 24, the next cycle, its minimum appears likely to occur in 2006, especially if it is a robust cycle similar in nature to cycles 17-23.

  10. On the Importance of Cycle Minimum in Sunspot Cycle Prediction

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    The characteristics of the minima between sunspot cycles are found to provide important information for predicting the amplitude and timing of the following cycle. For example, the time of the occurrence of sunspot minimum sets the length of the previous cycle, which is correlated by the amplitude-period effect to the amplitude of the next cycle, with cycles of shorter (longer) than average length usually being followed by cycles of larger (smaller) than average size (true for 16 of 21 sunspot cycles). Likewise, the size of the minimum at cycle onset is correlated with the size of the cycle's maximum amplitude, with cycles of larger (smaller) than average size minima usually being associated with larger (smaller) than average size maxima (true for 16 of 22 sunspot cycles). Also, it was found that the size of the previous cycle's minimum and maximum relates to the size of the following cycle's minimum and maximum with an even-odd cycle number dependency. The latter effect suggests that cycle 23 will have a minimum and maximum amplitude probably larger than average in size (in particular, minimum smoothed sunspot number Rm = 12.3 +/- 7.5 and maximum smoothed sunspot number RM = 198.8 +/- 36.5, at the 95-percent level of confidence), further suggesting (by the Waldmeier effect) that it will have a faster than average rise to maximum (fast-rising cycles have ascent durations of about 41 +/- 7 months). Thus, if, as expected, onset for cycle 23 will be December 1996 +/- 3 months, based on smoothed sunspot number, then the length of cycle 22 will be about 123 +/- 3 months, inferring that it is a short-period cycle and that cycle 23 maximum amplitude probably will be larger than average in size (from the amplitude-period effect), having an RM of about 133 +/- 39 (based on the usual +/- 30 percent spread that has been seen between observed and predicted values), with maximum amplitude occurrence likely sometime between July 1999 and October 2000.

  11. Cycles and Universality in Sunspot Number Fluctuations

    NASA Astrophysics Data System (ADS)

    Gonçalves, R.; Pinto, A. A.; Stollenwerk, N.

    2009-02-01

    We analyze the famous Wolf's sunspot numbers. Surprisingly, we discovered that the distribution of the sunspot number fluctuations for both the ascending and descending phases is close to the universal nonparametric Bramwell-Holdsworth-Pinton (BHP) distribution. Since the BHP probability density function appears in several other physical phenomena, our result reveals a universal feature of the Wolf's sunspot numbers.

  12. Sunspot Activity Near Cycle Minimum and What it Might Suggest for Cycle 24, the Next Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2009-01-01

    In late 2008, 12-month moving averages of sunspot number, number of spotless days, number of groups, area of sunspots, and area per group were reflective of sunspot cycle minimum conditions for cycle 24, these values being of or near record value. The first spotless day occurred in January 2004 and the first new-cycle, high-latitude spot was reported in January 2008, although old-cycle, low-latitude spots have continued to be seen through April 2009, yielding an overlap of old and new cycle spots of at least 16 mo. New-cycle spots first became dominant over old-cycle spots in September 2008. The minimum value of the weighted mean latitude of sunspots occurred in May 2007, measuring 6.6 deg, and the minimum value of the highest-latitude spot followed in June 2007, measuring 11.7 deg. A cycle length of at least 150 mo is inferred for cycle 23, making it the longest cycle of the modern era. Based on both the maximum-minimum and amplitude-period relationships, cycle 24 is expected to be only of average to below-average size, peaking probably in late 2012 to early 2013, unless it proves to be a statistical outlier.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.%

  18. 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.

  19. Development of sunspot cycle 24 past its peak in 2013

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    The smooth sunspot numbers for cycle 24 have been increasing slowly since its onset in December 2008. As per our prediction, cycle 24 reached its peak (smooth) sunspot numbers in May 2013 and is only half as active as cycle 23; it lingered near its peak while the polarity of the magnetic field at solar poles reversed over a period of more than a year; its descent toward the minimum has set in. We report on the present status of the descending phase of cycle 24 and compare its timeline with those of the previous ten cycles (14-23) of the twentieth century, with particular emphasis on those of cycles 5 and 14 that led to the start of two recent grand minima, namely the Dalton and the Gleissberg minima respectively. The implications for cycle 25 and 26 are discussed.

  20. On the maximum rate of change in sunspot number growth and the size of the sunspot cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1990-01-01

    Statistically significant correlations exist between the size (maximum amplitude) of the sunspot cycle and, especially, the maximum value of the rate of rise during the ascending portion of the sunspot cycle, where the rate of rise is computed either as the difference in the month-to-month smoothed sunspot number values or as the 'average rate of growth' in smoothed sunspot number from sunspot minimum. Based on the observed values of these quantities (equal to 10.6 and 4.63, respectively) as of early 1989, it is inferred that cycle 22's maximum amplitude will be about 175 + or - 30 or 185 + or - 10, respectively, where the error bars represent approximately twice the average error found during cycles 10-21 from the two fits.

  1. The 11 years solar cycle as the manifestation of the dark Universe

    SciTech Connect

    Zioutas, K.; Semertzidis, Y.; Tsagri, M.; Papaevangelou, T.; Hoffmann, D. H.H.; Anastassopoulos, V.

    2014-11-26

    Sun’s luminosity in the visible changes at the 10-3 level, following an 11 years period. In X-rays, which should not be there, the amplitude varies even ~105 times stronger, making their mysterious origin since the discovery in 1938 even more puzzling, and inspiring. We suggest that the multifaceted mysterious solar cycle is due to some kind of dark matter streams hitting the Sun. Planetary gravitational lensing enhances (occasionally) slow moving flows of dark constituents towards the Sun, giving rise to the periodic behaviour. Jupiter provides the driving oscillatory force, though its 11.8 years orbital period appears slightly decreased, just as 11 years, if the lensing impact of other planets is included. Then, the 11 years solar clock may help to decipher (overlooked) signatures from the dark sector in laboratory experiments or observations in space.

  2. The 11 years solar cycle as the manifestation of the dark Universe

    NASA Astrophysics Data System (ADS)

    Zioutas, K.; Tsagri, M.; Semertzidis, Y. K.; Papaevangelou, T.; Hoffmann, D. H. H.; Anastassopoulos, V.

    2014-11-01

    Sun's luminosity in the visible changes at the 10-3 level, following the 11 years period. This variation increases with energy, and in X-rays, which should not even be there, the amplitude varies up to 105 times stronger, making their mysterious origin since the discovery in 1938 even more puzzling, and inspiring. We suggest that the multifaceted mysterious solar cycle is due to some kind of dark matter streams hitting the Sun. Planetary gravitational lensing enhances (occasionally) slow moving flows of dark constituents toward the Sun, giving rise to the periodic behavior. Jupiter provides the driving oscillatory force, though its 11.8 years orbital period appears slightly decreased, just as 11 years, if the lensing impact of other planets is included. Then, the 11 years solar clock may help to decipher (overlooked) signatures from the dark sector in laboratory experiments or observations in space.

  3. The 11 years solar cycle as the manifestation of the dark Universe

    DOE PAGES

    Zioutas, K.; Semertzidis, Y.; Tsagri, M.; ...

    2014-11-26

    Sun’s luminosity in the visible changes at the 10-3 level, following an 11 years period. In X-rays, which should not be there, the amplitude varies even ~105 times stronger, making their mysterious origin since the discovery in 1938 even more puzzling, and inspiring. We suggest that the multifaceted mysterious solar cycle is due to some kind of dark matter streams hitting the Sun. Planetary gravitational lensing enhances (occasionally) slow moving flows of dark constituents towards the Sun, giving rise to the periodic behaviour. Jupiter provides the driving oscillatory force, though its 11.8 years orbital period appears slightly decreased, just asmore » 11 years, if the lensing impact of other planets is included. Then, the 11 years solar clock may help to decipher (overlooked) signatures from the dark sector in laboratory experiments or observations in space.« less

  4. Cyclicity of Suicides May Be Modulated by Internal or External - 11-Year Cycles: An Example of Suicide Rates in Finland

    NASA Astrophysics Data System (ADS)

    Dimitrov, B. D.; Atanassova, P. A.; Rachkova, M. I.

    2009-12-01

    Multicomponent cyclicity in monthly suicides (periods T = 18, 46 and 198 months) was found and close similarity with heliogeophysical activity (HGA) suggested by Dimitrov in 1999. The current report aimed at scrutinizing the results on suicide annual cyclicity (seasonality) in Slovenia as reported by Oravecz et al in 2007 as well as at analyzing suicide data from Finland in this regard. We postulated that: (i) trans-year (12-24 months) or far-trans-year long-term cycles of suicides might interfere with their seasonality; and (ii) associations to environmental factors with alike cyclicity (e.g. HGA, temperature) could exist. Annual suicide incidence from Oulu, Finland over years 1987-1999 was analyzed. Annual data on solar activity (sunspot index Rz or Wolf number), planetary geomagnetic activity (aa-index) and local daily mean temperatures were used. The exploration of underlying chronomes (time structures) was done by periodogram regression analysis with trigonometric approximation. We analyzed temporal dynamics, revealed cyclicity, decomposed and reconstructed significant cycles and correlated the time series data. Suicide seasonality in Slovenia during the years 1971-2002 (n=384 months, peak May-June) was considered and, although some discrepancies and methodological weaknesses were suspected, we further hypothesized about trans-year and/or longer (far-transyear) cyclic components. Suicide incidence data from Finland indicated that the 12.5-year cyclic component (or trend) was almost parallel (coherent) to the cyclic heliogeophysical parameters and similar to local decreasing temperature dynamics. Also, 8-year and 24.5-year cycles were revealed. A correlation between the 12.5-year suicide cycle and 11-year solar cycle was found (R=0.919, p=0.000009). Above findings on cyclicity and temporal correlations of suicides with cyclic environmental factors, even being still preliminary, might not only allow for further more specific analyses. They might also corroborate

  5. Properties of sunspot umbrae observed in cycle 24

    NASA Astrophysics Data System (ADS)

    Kiess, Christoph; Rezaei, Reza; Schmidt, Wolfgang

    2014-05-01

    Aims: There is an ongoing debate whether the solar activity cycle is overlaid with a long-term decline that may lead to another grand minimum in the near future. We used the size, intensity, and magnetic field strength of sunspot umbrae to compare the present cycle 24 with the previous one. Methods: We used data of the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and selected all sunspots between May 2010 and October 2012, using one image per day. We created two subsets of this dataset with a manual tracking algorithm, both without duplication. One contains each sunspot (910 umbrae within 488 spots) and was used to analyze the distribution of umbral areas, selected with an automated thresholding method. The other subset contains 205 fully evolved sunspots. We estimated their magnetic field and the total magnetic flux and discuss the relations between umbral size, minimum continuum intensity, maximum field strength, and total magnetic flux. Results: We find non-linear relations between umbral minimum intensity and size and between maximum magnetic field strength and size. The field strength scales linearly with the intensity and the umbral size scales roughly linearly with the total magnetic flux, while the size and field strength level off with stronger flux. When separated into hemispheres and averaged temporally, the southern umbrae show a temporal increase in size and the northern umbrae remain constant. We detected no temporal variation in the umbral mean intensity. The probability density function of the umbral area in the ascending phase of the current solar cycle is similar to that of the last solar cycle. Conclusions: From our investigation of umbral area, magnetic field, magnetic flux, and umbral intensity of the sunspots of the rising phase of cycle 24, we do not find a significant difference to the previous cycle, and hence no indication for a long-term decline of solar activity.

  6. Relationship between phases of quasi-decadal oscillations of total ozone and the 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Visheratin, K. N.

    2012-02-01

    Temporal variability of the relationship between the phases of quasi-decadal oscillations (QDOs) of total ozone (TO), measured at the Arosa station, and the Ri international sunspot number have been analyzed for the period of 1932-2009. Before the 1970s, the maximum phase of ozone QDOs lagged behind solar activity variations by about 2.5-2.8 years and later outstripped by about 1.5 years. We assumed that the TO QDOs in midlatitudes of the Northern Hemisphere were close to being in resonance with solar activity oscillations in the period from the mid-1960s to the mid-1970s and assessed the characteristic delay period of TO QDOs. The global distribution of phases and amplitudes of TO QDOs have been studied for the period from 1979 to 2008 based on satellite data. The maximum phase of TO QDOs first onsets in northern middle and high latitudes and coincides with the end of the growth phase of the 11-year solar cycle. In the tropics, the maximum oscillation phase lags behind by 0.5-1 year. The maximum phase lag near 40-50° S is about two years. The latitudinal variations of the phase of TO QDOs have been approximated.

  7. On the Relation Between Spotless Days and the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2005-01-01

    Spotless days are examined as a predictor for the size and timing of a sunspot cycle. For cycles 16-23 the first spotless day for a new cycle, which occurs during the decline of the old cycle, is found to precede minimum amplitude for the new cycle by about approximately equal to 34 mo, having a range of 25-40 mo. Reports indicate that the first spotless day for cycle 24 occurred in January 2004, suggesting that minimum amplitude for cycle 24 should be expected before April 2007, probably sometime during the latter half of 2006. If true, then cycle 23 will be classified as a cycle of shorter period, inferring further that cycle 24 likely will be a cycle of larger than average minimum and maximum amplitudes and faster than average rise, peaking sometime in 2010.

  8. 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.

  9. Sunspot Sizes and the Solar Cycle: Analysis Using Kodaikanal White-light Digitized Data

    NASA Astrophysics Data System (ADS)

    Mandal, Sudip; Banerjee, Dipankar

    2016-10-01

    Sizes of the sunspots vary widely during the progression of a solar cycle. Long-term variation studies of different sunspot sizes are key to better understand the underlying process of sunspot formation and their connection to the solar dynamo. The Kodaikanal white-light digitized archive provides daily sunspot observations for a period of 90 years (1921-2011). Using different size criteria on the detected individual sunspots, we have generated yearly averaged sunspot area time series for the full Sun as well as for the individual hemispheres. In this Letter, we have used the sunspot area values instead of sunspot numbers used in earlier studies. Analysis of these different time series show that different properties of the sunspot cycles depend on the sunspot sizes. The “odd-even rule” double peaks during the cycle maxima and the long-term periodicities in the area data are found to be present for specific sunspot sizes and are absent or not so prominent in other size ranges. Apart from that, we also find a range of periodicities in the asymmetry index that have a dependency on the sunspot sizes. These statistical differences in the different size ranges may indicate that a complex dynamo action is responsible for the generation and dynamics of sunspots with different sizes.

  10. Evidence for low dimensional chaos in sunspot cycles

    NASA Astrophysics Data System (ADS)

    Letellier, C.; Aguirre, L. A.; Maquet, J.; Gilmore, R.

    2006-04-01

    Sunspot cycles are widely used for investigating solar activity. In 1953 Bracewell argued that it is sometimes desirable to introduce the inversion of the magnetic field polarity, and that can be done with a sign change at the beginning of each cycle. It will be shown in this paper that, for topological reasons, this so-called Bracewell index is inappropriate and that the symmetry must be introduced in a more rigorous way by a coordinate transformation. The resulting symmetric dynamics is then favourably compared with a symmetrized phase portrait reconstructed from the z-variable of the Rössler system. Such a link with this latter variable - which is known to be a poor observable of the underlying dynamics - could explain the general difficulty encountered in finding evidence of low-dimensional dynamics in sunspot data.

  11. Association between the 11-Year Solar Cycle and the Atmosphere. Part V: Summer.

    NASA Astrophysics Data System (ADS)

    Labitzke, K.; van Loon, H.

    1992-03-01

    We describe a 10-12-year oscillation (abbreviated to TTO in the following) in the upper troposphere and lower stratosphere of the Northern Hemisphere in summer. The TTO has been presented since the time series began in 1951, and it has been in phase with the 11-year solar cycle during that time. The analyses show that the large amplitude of the TTO in the geopotential heights of the lower stratosphere is associated with temperature variations on the same time scale in the upper troposphere.

  12. Communicating the science of the 11-year sunspot cycle to the general public

    NASA Astrophysics Data System (ADS)

    Choudhuri, A. R.

    2015-03-01

    Astrophysics is one branch of science which excites the imagination of the general public. Pioneer science popularizers like George Gamow and Fred Hoyle wrote on different aspects of astrophysics. However, of late, we see a trend which I find disturbing. While it has become extremely fashionable to write popular science books on cosmology, other areas of astrophysics are grossly neglected.

  13. Spot cycle reconstruction: an empirical tool. Application to the sunspot cycle

    NASA Astrophysics Data System (ADS)

    Santos, A. R. G.; Cunha, M. S.; Avelino, P. P.; Campante, T. L.

    2015-08-01

    Context. The increasing interest in understanding stellar magnetic activity cycles is a strong motivation for the development of parameterized starspot models which can be constrained observationally. Aims: In this work we develop an empirical tool for the stochastic reconstruction of sunspot cycles, using the average solar properties as a reference. Methods: The synthetic sunspot cycle is compared with the sunspot data extracted from the National Geophysical Data Center, in particular using the Kolmogorov-Smirnov test. This tool yields synthetic spot group records, including date, area, latitude, longitude, rotation rate of the solar surface at the group's latitude, and an identification number. Results: Comparison of the stochastic reconstructions with the daily sunspot records confirms that our empirical model is able to successfully reproduce the main properties of the solar sunspot cycle. As a by-product of this work, we show that the Gnevyshev-Waldmeier rule, which describes the spots' area-lifetime relation, is not adequate for small groups and we propose an effective correction to that relation which leads to a closer agreement between the synthetic sunspot cycle and the observations. Appendix A is available in electronic form at http://www.aanda.org

  14. Chaos in the sunspot cycle - Analysis and prediction

    NASA Technical Reports Server (NTRS)

    Mundt, Michael D.; Maguire, W. Bruce, II; Chase, Robert R. P.

    1991-01-01

    The variability of solar activity over long time scales, given semiquantitatively by measurements of sunspot numbers, is examined as a nonlinear dynamical system. First, a discussion of the data set used and the techniques utilized to reduce the noise and capture the long-term dynamics inherent in the data is presented. Subsequently, an attractor is reconstructed from the data set using the method of time delays. The reconstructed attractor is then used to determine both the dimension of the underlying system and also the largest Lyapunov exponent, which together indicate that the sunspot cycle is indeed chaotic and also low dimensional. In addition, recent techniques of exploiting chaotic dynamics to provide accurate, short-term predictions are utilized in order to improve upon current forecasting methods and also to place theoretical limits on predictability extent. The results are compared to chaotic solar-dynamo models as a possible physically motivated source of this chaotic behavior.

  15. Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Upton, Lisa

    2013-01-01

    We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow can modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields.

  16. Egeson's (George's) transtridecadal weather cycling and sunspots

    NASA Astrophysics Data System (ADS)

    Halberg, F.; Cornélissen, G.; Bernhardt, K.-H.; Sampson, M.; Schwartzkopff, O.; Sonntag, D.

    2010-09-01

    In the late 19th century, Charles Egeson, a map compiler at the Sydney Observatory, carried out some of the earliest research on climatic cycles, linking them to about 33-year cycles in solar activity, and predicted that a devastating drought would strike Australia at the turn of the 20th century. Eduard Brückner and William J. S. Lockyer, who, like Egeson, found similar cycles, with notable exceptions, are also, like the map compiler, mostly forgotten. But the transtridecadal cycles are important in human physiology, economics and other affairs and are particularly pertinent to ongoing discusions of climate change. Egeson's publication of daily weather reports preceded those officially recorded. Their publication led to clashes with his superiors and his personal life was marked by run-ins with the law and, possibly, an implied, but not proven, confinement in an insane asylum and premature death. We here track what little is known of Egeson's life and of his bucking of the conventional scientific wisdom of his time with tragic results.

  17. Egeson's (George's) transtridecadal weather cycling and sunspots.

    PubMed

    Halberg, F; Cornélissen, G; Bernhardt, K-H; Sampson, M; Schwartzkopff, O; Sonntag, D

    2010-09-01

    In the late 19th century, Charles Egeson, a map compiler at the Sydney Observatory, carried out some of the earliest research on climatic cycles, linking them to about 33-year cycles in solar activity, and predicted that a devastating drought would strike Australia at the turn of the 20th century. Eduard Brückner and William J. S. Lockyer, who, like Egeson, found similar cycles, with notable exceptions, are also, like the map compiler, mostly forgotten. But the transtridecadal cycles are important in human physiology, economics and other affairs and are particularly pertinent to ongoing discusions of climate change. Egeson's publication of daily weather reports preceded those officially recorded. Their publication led to clashes with his superiors and his personal life was marked by run-ins with the law and, possibly, an implied, but not proven, confinement in an insane asylum and premature death. We here track what little is known of Egeson's life and of his bucking of the conventional scientific wisdom of his time with tragic results.

  18. Galactic cosmic ray modulation for sunspot cycle 24

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    The galactic cosmic ray (GCR) modulation at earth orbit is studied for the sunspot cycle 24 using data from the global network of neutron monitors, balloon measurements at high latitudes in Russia, and directional muon telescopes at Nagoya. The observed decrease in GCR intensity is modest compared to previous cycles. The tilt angle of heliospheric current sheet is at its maximum value for a cycle, solar polar fields have reversed, interplanetary magnetic field intensity at earth orbit is at peak (lower than prior cycles). So, one expects GCR intensity to be most depressed. A determination is made of rigidity dependence of the observed modulation. It is a power law with an exponent not too different from that observed for prior cycles (20-23).

  19. On the ambiguous nature of the 11-year solar cycle signal profile in stratospheric ozone

    NASA Astrophysics Data System (ADS)

    Dhomse, Sandip; Chipperfield, Martyn; Damadeo, Robert; Zawodny, Joe; Ball, William; Feng, Wuhu; Hossaini, Ryan; Mann, Graham; Haigh, Joana

    2016-04-01

    We use three satellite datasets and simulations from a 3-D chemical transport model, forced by three different solar flux datasets, to diagnose the 11-year solar cycle signal (SCS) in stratospheric ozone. Our analysis shows that compared to SAGE II v6.2, a reduced upper stratospheric SCS in SAGE II v7.0 is due to a more realistic ozone-temperature anti-correlation. Overall, all model simulations show a positive SCS in the lower and middle stratosphere and negligible SCS in the upper stratosphere in agreement with SAGE v7.0, HALOE and MLS data. The model simulations show a differently structured SCS over different time periods covered by the satellite datasets, which helps to resolve some observed differences. However, despite the improvements to the SAGE II data, due to remaining biases in current observational and reanalysis datasets, accurate quantification of the influence of solar flux variability on the climate system remains an open scientific question.

  20. Solar Cycle Variations of Sunspot Magnetic Field Strengths from the Mount Wilson Observatory

    NASA Astrophysics Data System (ADS)

    Pevtsov, Alexei A.; Bertello, L.; Tlatov, A.; Nagovitsyn, Y.; Kilcik, A.

    2012-05-01

    We used historical synoptic data the Mount Wilson Observatory (MWO) to study long-term changes in sunspot magnetic field strengths over the period of 1920-1959. By selecting sunspots with the strongest field strength for each observing day, we find that the average field strengths in sunspots vary with solar cycle with amplitude of a few hundred Gauss. The data show no statistically significant long-term trend over the period of about 40 years covered by these observations. We also find that the fractional distribution of sunspots changes from cycle to cycle. From Cycle 15 to Cycle 19, MWO data show a steady increase in fraction of sunspots with weaker field strengths (<1000 G), while the fraction of sunspots with strongest field strengths (>3000 G) steadily decreases. The fraction of sunspots with field strengths between 1000-3000 Gauss does not change in any systematic way. In contract, the fractional distribution of sunspots by their area (i.e., small, intermediate, and large) taken from the Greenwich observatory data set does not change during the same period of time. The different behavior in these two fractional distributions might indicate some physical changes in the properties of sunspots (e.g., sunspots of about the same area show progressively smaller field strengths), or it could be the result of some systematic instrumental/observational effects. We discuss our findings in the framework of these two possible explanations.

  1. 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.

  2. 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.

  3. Total ozone and the 11-yr sunspot cycle

    NASA Astrophysics Data System (ADS)

    Labitzke, K.; van Loon, H.

    1997-01-01

    The correlations between the total column ozone observed by TOMS and the 11-yr sunspot cycle are lowest in the equatorial region, where ozone is produced, and in the subpolar regions, where the largest amounts are found. In the annual mean the highest, statistically significant, correlations lie between the 5° and 30° parallels of latitude in either hemisphere-between the area of production and the areas of plenty. This position of the largest correlations suggests that the association between the Sun and the ozone is not a direct, radiative one, but that it is due to solar induced changes in the transport of ozone, that is, to changes in the atmospheric circulation. The highest tropical-subtropical correlations move with the Sun from summer hemisphere to summer hemisphere. The subtropical geopotential heights in the ozone layer are higher in the peaks than in the valleys of the 11-yr sunspot cycle. It is probable that the higher subtropical geopotentials in solar maxima depress the poleward transport of ozone through the subtropics and therefore create an abundance of ozone in the tropics relative to the solar minima. These results are based on a 15-yr series of ozone observations and may thus not necessarily be representative of a longer period.

  4. The proposed "Waldmeier discontinuity": How does it affect to sunspot cycle characteristics?

    NASA Astrophysics Data System (ADS)

    Pérez Aparicio, Alejandro Jesús; Vaquero, José Manuel; Cruz Gallego, María

    2012-08-01

    Recently, Svalgaard has proposed that Waldmeier introduced a discontinuity in the International Sunspot Number (ISN) around 1945. In this paper, we study some characteristics of the sunspot cycle using the classical ISN and the proposed version derived from the "Waldmeier discontinuity". We conclude that this proposed version does not significantly improve the statistics of the characteristics of solar cycle.

  5. 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.

  6. Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes

    NASA Astrophysics Data System (ADS)

    Hathaway, David H.; Upton, L.

    2013-07-01

    We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow should also modulate the amplitude of the following sunspot cycle through its influence on the Sun’s polar fields. The observational evidence and the theoretical consequences (similar to those of Cameron and Schussler (2012)) will be described. Komm, Howard, and Harvey (1993) Solar Phys. 147, 207. Cameron and Schussler (2012) Astron. Astrophys. 548, A57.

  7. Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Upton, Lisa

    2013-01-01

    We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow should also modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields. The observational evidence and the theoretical consequences (similar to those of Cameron and Schussler (2012)) will be described.

  8. Sunspots, Space Weather and Climate

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2009-01-01

    Four hundred years ago this year the telescope was first used for astronomical observations. Within a year, Galileo in Italy and Harriot in England reported seeing spots on the surface of the Sun. Yet, it took over 230 years of observations before a Swiss amateur astronomer noticed that the sunspots increased and decreased in number over a period of about 11 years. Within 15 years of this discovery of the sunspot cycle astronomers made the first observations of a flare on the surface of the Sun. In the 150 years since that discovery we have learned much about sunspots, the sunspot cycle, and the Sun s explosive events - solar flares, prominence eruptions and coronal mass ejections that usually accompany the sunspots. These events produce what is called Space Weather. The conditions in space are dramatically affected by these events. Space Weather can damage our satellites, harm our astronauts, and affect our lives here on the surface of planet Earth. Long term changes in the sunspot cycle have been linked to changes in our climate as well. In this public lecture I will give an introduction to sunspots, the sunspot cycle, space weather, and the possible impact of solar variability on our climate.

  9. The formation of the sunspot and magnetic cycles in the GCR intensity in the heliosphere

    NASA Astrophysics Data System (ADS)

    Kalinin, M. S.; Krainev, M. B.

    2013-02-01

    We compare the different approaches (observational and theoretical) to the definition and separation of the GCR intensity variations due to the changing number and area of sunspots (the sunspot cycle) and the changing polarity of the high-latitude solar magnetic fields (the magnetic cycle). Using the theoretical approach we can consider how both types of the GCR intensity variations change with energy in different parts of the heliosphere during the minima of the sunspot cycle and their relative weights in the calculated intensity.

  10. 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.

  11. 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.

  12. Fluctuations of the Caspian Sea level in the quasi-two-year and 11-year cycles of solar activity

    SciTech Connect

    Nuzhdina, M.A.

    1995-07-01

    Fluctuations of the Caspian Sea level due to dynamics of solar activity in its quasi-two-year and 11-year cycles, as well as to the influence of the 22-to 23-year magnetic cycle are analyzed. Perturbation of the geomagnetic field and the atmospheric circulation are regarded as a transmitting mechanism of the Sun`s influence on the Earth`s hydrosphere.

  13. Sunspot analysis and prediction

    NASA Technical Reports Server (NTRS)

    Steyer, C. C.

    1971-01-01

    An attempt is made to develop an accurate functional representation, using common trigonometric functions, of all existing sunspot data, both quantitative and qualitative, ancient and modern. It is concluded that the three periods of high sunspot activity (1935 to 1970, 1835 to 1870, and 1755 to 1790) are independent populations. It is also concluded that these populations have long periods of approximately 400, 500, and 610 years, respectively. The difficulties in assuming a periodicity of seven 11-year cycles of approximately 80 years are discussed.

  14. An Examination of Selected Geomagnetic Indices in Relation to the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    Previous studies have shown geomagnetic indices to be useful for providing early estimates for the size of the following sunspot cycle several years in advance. Examined this study are various precursor methods for predicting the minimum and maximum amplitude of the following sunspot cycle, these precursors based on the aa and Ap geomagnetic indices and the number of disturbed days (NDD), days when the daily Ap index equaled or exceeded 25. Also examined is the yearly peak of the daily Ap index (Apmax), the number of days when Ap greater than or equal to 100, cyclic averages of sunspot number R, aa, Ap, NDD, and the number of sudden storm commencements (NSSC), as well the cyclic sums of NDD and NSSC. The analysis yields 90-percent prediction intervals for both the minimum and maximum amplitudes for cycle 24, the next sunspot cycle. In terms of yearly averages, the best regressions give Rmin = 9.8+/-2.9 and Rmax = 153.8+/-24.7, equivalent to Rm = 8.8+/-2.8 and RM = 159+/-5.5, based on the 12-mo moving average (or smoothed monthly mean sunspot number). Hence, cycle 24 is expected to be above average in size, similar to cycles 21 and 22, producing more than 300 sudden storm commencements and more than 560 disturbed days, of which about 25 will be Ap greater than or equal to 100. On the basis of annual averages, the sunspot minimum year for cycle 24 will be either 2006 or 2007.

  15. 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

  16. Application of Cross Wavelet Transform and Wavelet coherence to sunspot area and sunspot number during the ascending phase of solar cycle 24

    NASA Astrophysics Data System (ADS)

    Kasde, Satish Kumar; Gwal, Ashok Kumar; Sondhiya, Deepak Kumar

    Abstract: To understand better the variation of solar activity indicators originated at different layers of the solar atmosphere with respect to sunspot cycles, we carried out a study of phase relationship between sunspot number and Sunspot area using cross-correlation analysis. Extended wavelet based approaches such as continuous wavelet transform (CWT), cross wavelet transform (XWT), and wavelet coherence (WTC). It gives better understanding in the physical processes responsible for the solar activity and the solar cycle phenomenon. In this study we found: short term variability for current solar cycle 24 (Jan2008 - May2013). We have observed the mid-term quasi periodicities for this solar cycle and we also investigate the correlation between both parameters and identify the unusual conditions in space weather. Key words: Wavelet analysis, Sunspot Cycle, Solar Activity.

  17. Difference between even and odd 11-year cycles in cosmic ray intensity

    NASA Technical Reports Server (NTRS)

    Otaola, J. A.; Perez-Enriquez, R.; Valdes-Galicia, J. F.

    1985-01-01

    Cosmic ray data for the period 1946-1984 are used to determine the run of the cosmic ray intensity over three complete solar cycles. The analysis shows a tendency towards a regular alternation of cosmic ray intensity cycles with double and single maxima. Whereas a saddle-like shape is characteristic of even cycles, odd cycles are characterized by a peak-like shape. The importance of this behavior is discussed in terms of different processes influencing cosmic ray transport in the heliosphere.

  18. Digitized archive of the Kodaikanal images: Representative results of solar cycle variation from sunspot area determination

    NASA Astrophysics Data System (ADS)

    Ravindra, B.; Priya, T. G.; Amareswari, K.; Priyal, M.; Nazia, A. A.; Banerjee, D.

    2013-02-01

    Context. Sunspots have been observed since Galileo Galilei invented the telescope. Later, sunspot drawings have been upgraded to image storage using photographic plate in the second half of nineteenth century. These photographic images are valuable data resources for studying long-term changes in the solar magnetic field and its influence on the Earth's climate and weather. Aims: Digitized photographic plates cannot be used directly for the scientific analysis. It requires certain steps of calibration and processing before using them for extracting any useful information. The final data can be used to study solar cycle variations over several cycles. Methods: We digitized more than 100 years of white-light images stored in photographic plates and films that are available at Kodaikanal observatory starting from 1904. The images were digitized using a 4k × 4k format CCD-camera-based digitizer unit.The digitized images were calibrated for relative plate density and aligned in such a way that the solar north is in upward direction. A semi-automated sunspot detection technique was used to identify the sunspots on the digitized images. Results: In addition to describing the calibration procedure and availability of the data, we here present preliminary results on the sunspot area measurements and their variation with time. The results show that the white-light images have a uniform spatial resolution throughout the 90 years of observations. However, the contrast of the images decreases from 1968 onwards. The images are circular and do not show any major geometrical distortions. The measured monthly averaged sunspot areas closely match the Greenwich sunspot area over the four solar cycles studied here. The yearly averaged sunspot area shows a high degree of correlation with the Greenwich sunspot area. Though the monthly averaged sunspot number shows a good correlation with the monthly averaged sunspot areas, there is a slight anti-correlation between the two during solar

  19. The spiral interplanetary magnetic field - A polarity and sunspot cycle variation

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1974-01-01

    Spacecraft observations near the earth of the average direction of the interplanetary magnetic field during the sunspot maximum year 1968 showed a deviation from the spiral field of Parker's classical description. The included angle between the average field direction when the field polarity was away from the sun and the average direction when the field polarity was toward the sun was 168 deg, rather than 180 deg as predicted by Parker. This effect appears to have a sunspot cycle variation.

  20. The spiral interplanetary magnetic field: A polarity and sunspot cycle variation

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1974-01-01

    Spacecraft observations near the earth of the yearly average direction of the interplanetary magnetic field during the sunspot maximum year 1968 showed a deviation from the spiral field. The angle between the average field direction when the field polarity was away from the sun and the average direction for toward polarity was 168 deg, rather than 180 deg. This effect appears to have a sunspot cycle variation.

  1. 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.

  2. 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.

  3. The statistical study of global properties of sunspots observed by SoHO/MDI continuum images over solar cycle 23

    NASA Astrophysics Data System (ADS)

    Goel, Suruchi; Krivova, Natalie; Solanki, Sami K.; Mathew, Shibu K.

    2016-07-01

    A better understanding of inter-dependency of various sunspot parameters such as magnetic field, intensity, temperature, size etc., and also their variation with strength of solar activity cycle is important to understand the magneto-convection process involved in sunspot formation and evolution and hence to develop a consistent sunspot model. We have investigated global sunspot properties using parameters of sunspots identified from stray-light-corrected continuum images from SoHO/MDI spanning from years 1996 to 2011. We find that the non-linear relation between umbral core (minimum) intensity and sunspot area is best represented by an exponential function, which reaches an asymptotic value at 600 MSH. For the first time we have also observed that the core intensity depends on shape of umbrae, i.e., circular umbrae are statistically darker compared to the elongated ones. The core intensity increases slightly towards the limb (by value of ~0.1 from disk center to the limb). From sunspots sampled over the complete solar cycle 23 and during the rising phase of cycle 24, we did not find any solar-cycle variation in umbral core intensity. The penumbra to umbra area ratio is found to be not a constant parameter, instead it shows a quadratic decrease with sunspot area. Leading and following sunspots usually have different morphological features, however in this study we did not observe significant differences in their core intensity and penumbra-umbra area ratio relation with the sunspot area.

  4. The Antarctic ozone minimum - Relationship to odd nitrogen, odd chlorine, the final warming, and the 11-year solar cycle

    NASA Technical Reports Server (NTRS)

    Callis, L. B.; Natarajan, M.

    1986-01-01

    Photochemical calculations along 'diabatic trajectories' in the meridional phase are used to search for the cause of the dramatic springtime minimum in Antarctic column ozone. The results indicate that the minimum is principally due to catalytic destruction of ozone by high levels of total odd nitrogen. Calculations suggest that these levels of odd nitrogen are transported within the polar vortex and during the polar night from the middle to upper stratosphere and lower mesosphere to the lower stratosphere. The possibility that these levels are related to the 11-year solar cycle and are increased by enhanced formation in the thermosphere and mesosphere during solar maximum conditions is discussed.

  5. The sunspot cycle variations of the neutral line on the source surface

    NASA Technical Reports Server (NTRS)

    Saito, T.; Oki, T.; Akasofu, S.-I.; Olmsted, C.

    1989-01-01

    The earlier presentation method of the sunspot cycle variations of the neutral line on the source surface by introducing the view longitude is defined. It is shown that the neutral line seen from the view longitude and the equivalent dipole (determined by Hoeksema, 1984) showed a trend of rotation throughout the sunspot cycle. However, the surface bounded by the neutral line is generally far from a circle. In fact, our combined presentation of both the equivalnet dipole and the nuetral line indicates graphically that such a simple description of the rotating (equivalent) dipole may be misleading. The concept of an inclined dipole with respect to the rotation axis may also be misleading.

  6. The sunspot cycle variations of the neutral line on the source surface

    NASA Astrophysics Data System (ADS)

    Saito, T.; Oki, T.; Akasofu, S.-I.; Olmsted, C.

    1989-05-01

    The earlier presentation method of the sunspot cycle variations of the neutral line on the source surface by introducing the view longitude is defined. It is shown that the neutral line seen from the view longitude and the equivalent dipole (determined by Hoeksema, 1984) showed a trend of rotation throughout the sunspot cycle. However, the surface bounded by the neutral line is generally far from a circle. In fact, our combined presentation of both the equivalnet dipole and the nuetral line indicates graphically that such a simple description of the rotating (equivalent) dipole may be misleading. The concept of an inclined dipole with respect to the rotation axis may also be misleading.

  7. Application of Avco data analysis and prediction techniques (ADAPT) to prediction of sunspot activity

    NASA Technical Reports Server (NTRS)

    Hunter, H. E.; Amato, R. A.

    1972-01-01

    The results are presented of the application of Avco Data Analysis and Prediction Techniques (ADAPT) to derivation of new algorithms for the prediction of future sunspot activity. The ADAPT derived algorithms show a factor of 2 to 3 reduction in the expected 2-sigma errors in the estimates of the 81-day running average of the Zurich sunspot numbers. The report presents: (1) the best estimates for sunspot cycles 20 and 21, (2) a comparison of the ADAPT performance with conventional techniques, and (3) specific approaches to further reduction in the errors of estimated sunspot activity and to recovery of earlier sunspot historical data. The ADAPT programs are used both to derive regression algorithm for prediction of the entire 11-year sunspot cycle from the preceding two cycles and to derive extrapolation algorithms for extrapolating a given sunspot cycle based on any available portion of the cycle.

  8. Luni-solar 18.6- and solar cycle 10 - 11-year signals in USA air temperature records.

    NASA Astrophysics Data System (ADS)

    Currie, R. G.

    1993-02-01

    Spectrum analysis of 1197 USA air temperature records yields evidence for two peaks with periods 18.8±1.7 and 10.4±0.5 years. Tests by the t-statistic show that both are significant at confidence levels of 99.9 per cent, and both account for 23 per cent of total variance in the raw data. They are identified as the luni-solar 18.6 year Mn and solar cycle Sc 10 - 11 year signals in climate, induced by the twelfth largest constituent tide acting on the Earth and a variation of 10 to 11 years in the Sun's luminosity of the order of 0.1 per cent. Amplitude and phase of Mn wavetrains are highly non-stationary with respect to both time and geography; in particular, abrupt 180° phase changes in wave polarity are often observed. Amplitude and phase of the Sc waves are also highly non-stationary.

  9. 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.

  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. Sunspots motions in the 22^nd cycle of activity

    NASA Astrophysics Data System (ADS)

    Tomic, A. S.; Vince, I.

    2006-08-01

    We handled approximately 30 000 rows with data for 5744 sunspots, obtained on Debrecen Heliophysical Observatory, for years 1986-1989 and 1993-1995. By method of last squares we solved for each spot inverse relations between time of observation, angular distance from central meridian and latitude. On this way were obtained mean equatorial and mean meridional motion, giving parameters of rotation for 90 latitude zones width of one degree. The averaged sideral equatorial angular speed of rotation: omega = 2.91+/-0.01[micro rad/ day], and: A = -0.65+/-0/01 [micro rad/day] were obtained. Solving second inverse problem - Busso's equation, were derived characteristic equatorial periods for different latitudes, from sunspots meridional motion. We obtained values between 32 day on the pole, and 400 years for latitude 2.5 degree. Also, covariance of spot motions along equator and meridian is calculated for all 5744 spots in 90 degree of latitude, which fully confirmed Ward's model of angular moment transport.

  12. Harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle

    NASA Astrophysics Data System (ADS)

    Scafetta, N.

    2012-12-01

    We show that the Schwabe frequency band of the Zurich sunspot record since 1749 is made of three major cycles that are closely related to the spring tidal period of Jupiter and Saturn (~9.93 year), to the tidal sidereal period of Jupiter (about 11.86 years) and to a central cycle that may be associated to a quasi-11-year solar dynamo cycle. The central harmonic is approximately synchronized to the average of the two planetary frequencies. A harmonic model based on the above two planetary tidal frequencies and on the exact dates of Jupiter and Saturn planetary tidal phases, plus a theoretically deduced 10.87-year central cycle reveals major beat periods occurring at about 115, 61 and 130 years, plus a quasi-millennial large beat cycle around 983 years. Equivalent synchronized cycles are found in cosmogenic solar proxy records used to reconstruct solar activity and in proxy climate records throughout the Holocene (last 12,000 years) up to now. The quasi-secular beat oscillations hindcast reasonably well the known prolonged periods of low solar activity during the last millennium such as the Oort, Wolf, Sporer, Maunder and Dalton minima, as well as the 17 115-year long oscillations found in a detailed temperature reconstruction of the Northern Hemisphere covering the last 2000 years. The millennial three-frequency beat cycle hindcasts equivalent solar and climate cycles for 12,000 years. Finally, the harmonic model herein proposed reconstructs the prolonged solar minima around 1900-1920 and 1960-1980, the secular solar maxima around 1870-1890, 1940-1950 and 1995-2005, and a secular upward trending during the 20th century. The latter modulated trending agrees well with some solar proxy model, with the ACRIM TSI satellite composite and with the global surface temperature modulation since 1850. The model forecasts a new prolonged solar minimum during 2020-2045, which is produced by the minima of both the 61 and 115-year reconstructed cycles. Finally, the model predicts

  13. Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle

    NASA Astrophysics Data System (ADS)

    Scafetta, Nicola

    2012-05-01

    The Schwabe frequency band of the Zurich sunspot record since 1749 is found to be made of three major cycles with periods of about 9.98, 10.9 and 11.86 years. The side frequencies appear to be closely related to the spring tidal period of Jupiter and Saturn (range between 9.5 and 10.5 years, and median 9.93 years) and to the tidal sidereal period of Jupiter (about 11.86 years). The central cycle may be associated to a quasi-11-year solar dynamo cycle that appears to be approximately synchronized to the average of the two planetary frequencies. A simplified harmonic constituent model based on the above two planetary tidal frequencies and on the exact dates of Jupiter and Saturn planetary tidal phases, plus a theoretically deduced 10.87-year central cycle reveals complex quasi-periodic interference/beat patterns. The major beat periods occur at about 115, 61 and 130 years, plus a quasi-millennial large beat cycle around 983 years. We show that equivalent synchronized cycles are found in cosmogenic records used to reconstruct solar activity and in proxy climate records throughout the Holocene (last 12,000 years) up to now. The quasi-secular beat oscillations hindcast reasonably well the known prolonged periods of low solar activity during the last millennium such as the Oort, Wolf, Spörer, Maunder and Dalton minima, as well as the 17 115-year long oscillations found in a detailed temperature reconstruction of the Northern Hemisphere covering the last 2000 years. The millennial three-frequency beat cycle hindcasts equivalent solar and climate cycles for 12,000 years. Finally, the harmonic model herein proposed reconstructs the prolonged solar minima that occurred during 1900-1920 and 1960-1980 and the secular solar maxima around 1870-1890, 1940-1950 and 1995-2005 and a secular upward trending during the 20th century: this modulated trending agrees well with some solar proxy model, with the ACRIM TSI satellite composite and with the global surface temperature

  14. North-south asymmetry in small and large sunspot group activity and violation of even-odd solar cycle rule

    NASA Astrophysics Data System (ADS)

    Javaraiah, J.

    2016-07-01

    According to Gnevyshev-Ohl (G-O) rule an odd-numbered cycle is stronger than its preceding even-numbered cycle. In the modern time the cycle pair (22, 23) violated this rule. By using the combined Greenwich Photoheliographic Results (GPR) and Solar Optical Observing Network (SOON) sunspot group data during the period 1874-2015, and Debrecen Photoheliographic Data (DPD) of sunspot groups during the period 1974-2015, here we have found that the solar cycle pair (22, 23) violated the G-O rule because, besides during cycle 23 a large deficiency of small sunspot groups in both the northern and the southern hemispheres, during cycle 22 a large abundance of small sunspot groups in the southern hemisphere. In the case of large and small sunspot groups the cycle pair (22, 23) violated the G-O rule in the northern and southern hemispheres, respectively, suggesting the north-south asymmetry in solar activity has a significant contribution in the violation of G-O rule. The amplitude of solar cycle 24 is smaller than that of solar cycle 23. However, Coronal Mass Ejections (CMEs) rate in the rising phases of the cycles 23 and 24 are almost same (even slightly large in cycle 24). From both the SOON and the DPD sunspot group data here we have also found that on the average the ratio of the number (counts) of large sunspot groups to the number of small sunspot groups is larger in the rising phase of cycle 24 than that in the corresponding phase of cycle 23. We suggest this could be a potential reason for the aforesaid discrepancy in the CME rates during the rising phases of cycles 23 and 24. These results have significant implication on solar cycle mechanism.

  15. 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.

  16. Predicting the Size and Timing of Sunspot Maximum for Cycle 24

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2010-01-01

    For cycle 24, the minimum value of the 12-month moving average (12-mma) of the AA-geomagnetic index in the vicinity of sunspot minimum (AAm) appears to have occurred in September 2009, measuring about 8.4 nT and following sunspot minimum by 9 months. This is the lowest value of AAm ever recorded, falling below that of 8.9 nT, previously attributed to cycle 14, which also is the smallest maximum amplitude (RM) cycle of the modern era (RM = 64.2). Based on the method of Ohl (the preferential association between RM and AAm for an ongoing cycle), one expects cycle 24 to have RM = 55+/-17 (the +/-1 - sigma prediction interval). Instead, using a variation of Ohl's method, one based on using 2-cycle moving averages (2-cma), one expects cycle 23's 2-cma of RM to be about 115.5+/-8.7 (the +/-1 - sigma prediction interval), inferring an RM of about 62+/-35 for cycle 24. Hence, it seems clear that cycle 24 will be smaller in size than was seen in cycle 23 (RM = 120.8) and, likely, will be comparable in size to that of cycle 14. From the Waldmeier effect (the preferential association between the ascent duration (ASC) and RM for an ongoing cycle), one expects cycle 24 to be a slow-rising cycle (ASC > or equal to 48 months), having RM occurrence after December 2012, unless it turns out to be a statistical outlier.

  17. On the Correlation Between Maximum Amplitude and Smoothed Monthly Mean Sunspot Number during the Rise of the Cycle (from t = 0-48 months Past Sunspot Minimum)

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    During the rise from sunspot minimum to maximum, the observed value of smoothed monthly mean sunspot number at maximum RM is found to correlate with increasing strength against the current value of smoothed monthly mean sunspot number R(t), where t is the elapsed time in months from minimum. On the basis of the modern era sunspot cycles (i.e., cycles 10-22), the inferred linear correlation is found to be statistically important (i.e., at the 95-percent level of confidence) from about 11 mo past minimum and statistically very important (i.e.. at the 99-percent level of confidence) from about 15 mo past minimum; ignoring cycle 19, the largest cycle of the modern era, the inferred linear correlation is found to be statistically important from cycle onset. On the basis of R(t), estimates of RM can be gauged usually to within about +/- 30 percent during the first 2 yr and to within about +/- 20 percent (or better) after the first 2 yr of a cycle's onset. For cycle 23, because controversy exists regarding the placement of its minimum (i.e., its onset), being either May 1996 or perhaps August 1996 (or shortly thereafter), estimates of its RM are divergent, being lower (more like a mean size cycle) when using the earlier epoch of minimum and higher (above average in size) when using the later-occurring minimum. For smoothed monthly mean sunspot number through October 1997 (t = 17 or 14 mo, respectively), having a provisional value of 32.0. the earlier minimum date projects an RM of 110.3 +/- 33.1, while the later minimum date projects one of 137.2 +/- 41.2. The projection is slowly decreasing in size using the earlier onset date, while it is slowly increasing in size using the later onset date.

  18. Coronal evolution during the sunspot cycle: Coronal holes observed with the Mauna Loa K-coronameters

    SciTech Connect

    Hundhausen, A.J.; Hansen, R.T.; Hansen, S.F.

    1981-04-01

    The white-light corona was observed regularly at the Mauna Loa Observatory during the years 1965--1967 and 1969--1978. Display of the measured polarization brightness in the form of synoptic maps permits the identification of large coronal holes and the study of their slow evolution during the sunspot cycle. The polar coronal holes were clearly seen to shrink in size during the ascending phase of cycle 20 (1965--1967), to be absent during a two-year period (1969--1970) just after sunspot maximum, to reappear near the end of 1970, and to remain as prominent features of the corona for the years 1971--1978. During the sunspot maximum epoch the corona was dominated by 'mid-latitude' holes, elongated in the direction parallel to the solar equator. Large equatorial holes or equatorward extensions of the polar holes were observed during the ascending, maximum, and descending phases of cycle 20 and appear to be sources of solar wind streams with maximum speeds over 600 km s/sup -1/ at all of these epochs. The lifetimes of these holes and streams were greatest during the descending phase of the cycle, or in 1974--1975.

  19. The lunar cycle, sunspots and the frequency of births in Germany, 1920-1989.

    PubMed

    Bauer, Thomas K; Bender, Stefan; Heining, Jörg; Schmidt, Christoph M

    2013-12-01

    Based on multivariate linear regression models, we analyze the effect of the lunar cycle and the number of sunspots occurring on a particular day on the number of births using social security data and controlling for a number of other potential confounders. The daily numbers of births between 1920 and 1989 have been calculated from the full sample of individuals who have been registered at least once in the German social security system. While the lunar cycle does not affect the number of births, the number of sunspots is positively correlated to the number of births. The empirical results may be explained by medical technological progress making natural influences on births less important over time. This interpretation is supported by the results on the intertemporal influence of weekends and holidays on the frequency of daily births.

  20. Climate variability related to the 11 year solar cycle as represented in different spectral solar irradiance reconstructions

    NASA Astrophysics Data System (ADS)

    Kruschke, Tim; Kunze, Markus; Misios, Stergios; Matthes, Katja; Langematz, Ulrike; Tourpali, Kleareti

    2016-04-01

    shortwave heating rate differences (additionally collated with line-by-line calculations using libradtran), differences in the photolysis rates, as well as atmospheric circulation features (temperature, zonal wind, geopotential height, etc.). It is shown that atmospheric responses to the different SSI datasets differ significantly from each other. This is a result from direct radiative effects as well as indirect effects induced by ozone feedbacks. Differences originating from using different SSI datasets for the same level of solar activity are in the same order of magnitude as those associated with the 11 year solar cycle within a specific dataset. However, the climate signals related to the solar cycle are quite comparable across datasets.

  1. 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.

  2. THE SOLAR WIND AND INTERPLANETARY FIELD DURING VERY LOW AMPLITUDE SUNSPOT CYCLES

    SciTech Connect

    Wang, Y.-M.; Sheeley, N. R. Jr. E-mail: neil.sheeley@nrl.navy.mil

    2013-02-10

    Cosmogenic isotope records indicate that a solar-cycle modulation persists through extended periods of very low sunspot activity. One immediate implication is that the photospheric field during such grand minima did not consist entirely of ephemeral regions, which produce a negligible amount of open magnetic flux, but continued to have a large-scale component originating from active regions. Present-day solar and heliospheric observations show that the solar wind mass flux and proton density at the coronal base scale almost linearly with the footpoint field strength, whereas the wind speed at Earth is uncorrelated with the latter. Thus a factor of {approx}4-7 reduction in the total open flux, as deduced from reconstructions of the interplanetary magnetic field (IMF) during the Maunder Minimum, would lead to a similar decrease in the solar wind densities, while leaving the wind speeds largely unchanged. We also demonstrate that a decrease in the strengths of the largest active regions during grand minima will reduce the amplitude of the Sun's equatorial dipole relative to the axial component, causing the IMF strength to peak near sunspot minimum rather than near sunspot maximum, a result that is consistent with the phase shift observed in the {sup 10}Be record during the Maunder Minimum. Finally, we discuss the origin of the 5 yr periodicity sometimes present in the cosmogenic isotope data during low and medium amplitude cycles.

  3. Deciphering solar magnetic activity. I. On the relationship between the sunspot cycle and the evolution of small magnetic features

    SciTech Connect

    McIntosh, Scott W.; Wang, Xin; Markel, Robert S.; Thompson, Michael J.; Leamon, Robert J.; Malanushenko, Anna V.; Davey, Alisdair R.; Howe, Rachel; Krista, Larisza D.; Cirtain, Jonathan W.; Gurman, Joseph B.; Pesnell, William D.

    2014-09-01

    Sunspots are a canonical marker of the Sun's internal magnetic field which flips polarity every ∼22 yr. The principal variation of sunspots, an ∼11 yr variation, modulates the amount of the magnetic field that pierces the solar surface and drives significant variations in our star's radiative, particulate, and eruptive output over that period. This paper presents observations from the Solar and Heliospheric Observatory and Solar Dynamics Observatory indicating that the 11 yr sunspot variation is intrinsically tied to the spatio-temporal overlap of the activity bands belonging to the 22 yr magnetic activity cycle. Using a systematic analysis of ubiquitous coronal brightpoints and the magnetic scale on which they appear to form, we show that the landmarks of sunspot cycle 23 can be explained by considering the evolution and interaction of the overlapping activity bands of the longer-scale variability.

  4. A Normalized Sunspot-Area Series Starting in 1832: An Update

    NASA Astrophysics Data System (ADS)

    Carrasco, V. M. S.; Vaquero, J. M.; Gallego, M. C.; Sánchez-Bajo, F.

    2016-11-01

    A new normalized sunspot-area series has been reconstructed from the series obtained by the Royal Greenwich Observatory and other contemporary institutions for the period 1874 - 2008 and the area series compiled by De la Rue, Stewart, and Loewy from 1832 to 1868. Since the two sets of series do not overlap in time, we used the new version of sunspot index number (Version 2) published by Sunspot Index and Long-term Solar Observations (SILSO) as a link between them. We also present a spectral analysis of the normalized-area series in search of periodicities beyond the well-known solar cycle of 11 years and a study of the Waldmeier effect in the new version of sunspot number and the sunspot-area series presented in this study. We conclude that while this effect is significant in the new series of sunspot number, it has a weak relationship with the sunspot-area series.

  5. An empirical approach to predicting the key parameters for a sunspot number cycle

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2014-02-01

    The common methodologies used to predict the smooth sunspot number (SSN) at peak (Rmax) and the rise time (Tr) for a cycle are noted. The estimates based on geomagnetic precursors give the best prediction of Rmax for five SSN cycles (20-24). In particular, an empirical technique invoking three-cycle quasi-periodicity (TCQP) in Ap index has made accurate predictions of Rmax and Tr for two consecutive SSN cycles (23 and 24). The dynamo theories are unable to account for TCQP. If it endures in the 21st century the Sun shall enter a Dalton-like grand minimum. It was a period of global cooling. The current status of the ascending phase of cycle 24 is described and the delayed reversal of the solar polar field reversal in the southern hemisphere in September 2013 is noted.

  6. Altitude dependent sensitivity of equatorial atomic oxygen in the MLT region to the quasi-11-year and quasi-27-day solar cycles

    NASA Astrophysics Data System (ADS)

    Lednyts'kyy, Olexandr; Von Savigny, Christian

    2016-07-01

    We retrieved atomic oxygen concentration ([O]) profiles with help of volume emission rate (VER) profiles calculated from the measured by SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) emissions of green line nightglow in the MLT (Mesosphere/Lower Thermosphere) region. We quantified the sensitivity of equatorial [O] to the 11-year and 27-day solar cycle forcing represented by such proxy indicators of solar activity as MgII index and Lyman-α with help of the wavelet, cross-correlation, superposed epoch, regression and harmonical analysis methods. We applied ordinary least squares bisector fitting on MgII index and F10.7 radio flux, which is measured in solar flux units (sfu), to convert the [O] sensitivity values in sfu and finally in percent changes. The same procedure was performed in the case of Lyman-α. Our results of the sensitivity analysis correspond well to the 11-year solar cycle response of O volume mixing ratios found in simulations performed with the WACCM3 (Whole Atmosphere Community Climate Model, v. 3) and the HAMMONIA (3D Hamburg Model of the Neutral and Ionized Atmosphere) model. We identified an 11-year solar cycle variation, quasi-biennial and annual/semi-annual oscillations as well as signatures of the 27-day cycle of solar activity as presented in the MLT O layer. The most remarkable result is that the found sensitivities agree within their uncertainties and do not depend on averaging method (annual, monthly and daily) of the [O] time series. We report on 11-year and 27-day solar cycle signatures in dependence on altitude intervals used to average the [O] time series.

  7. On long-term periodicities in the sunspot record

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1984-01-01

    Sunspot records are systematically maintained, with the knowledge that an 11 year average period exists since about 1850. Thus, the sunspot record of highest quality and considered to be the most reliable is that of cycle eight through the present. On the basis of cycles 8 through 20, various combinations of sine curves were used to approximate the observed R sub MAX values (where R sub MAX is the smoothed sunspot number at cycle maximum). It is found that a three component sinusoidal function, having an 11 cycle and a 2 cycle variation on a 90 cycle periodicity, yields computed R sub MAX values which fit, reasonably well, observed R sub MAX values for the modern sunspot cycles. Extrapolation of the empirical functions forward in time allows for the projection of values of R sub MAX for cycles 21 and 22. For cycle 21, the function projects a value of 157.3, very close to the actually observed value of 164.5. For cycle 22, the function projects a value of about 107. Linear regressions applied to cycle 22 indicate a long-period cycle (cycle duration 132 months). An extensive bibliography on techniques used to estimate the time dependent behavior of sunspot cycles is provided.

  8. A new solar signal: Average maximum sunspot magnetic fields independent of activity cycle

    NASA Astrophysics Data System (ADS)

    Livingston, William; Watson, Fraser

    2015-11-01

    Over the past 5 years, 2010 to April 2015, we observed 4176 sunspot umbrae in the infrared (IR) to measure maximum magnetic field strengths from the Zeeman splitting of Fe 15,648.5 Å. Herein we distinguish "field strengths" from "field flux." Field strengths range from 1500 G in pores to 3500+ in large spots. We made one observation per spot per observing day, ignoring spot size. We show that in the IR no activity cycle dependence on average maximum field strength (2070 ± 20 G) has been found. A similar analysis of 17,450 spots observed in space by the Helioseismic and Magnetic Imager reveals a similar cycle independence (2050 ± 0.18 G). We conclude that the average maximum umbral fields are constant with time and independent of the activity cycle within our time coverage.

  9. Are the sunspots really vanishing?. Anomalies in solar cycle 23 and implications for long-term models and proxies

    NASA Astrophysics Data System (ADS)

    Clette, Frédéric; Lefèvre, Laure

    2012-06-01

    Context: The elapsed solar cycle (23) ended with an exceptionally long period of low activity and with unprecedented low levels for various series of solar irradiance and particle flux measurements. This unpredicted evolution of solar activity raised multiple questions about a future decline of the solar cycles and launched a quest for precursor signs of this possible deep solar transition over the last decade. Aim: We present here a review and overall interpretation of most current diagnostics of solar cycle 23, including the recent disagreements that appeared among solar reference indices and standard solar-based geo-indices, the indication of a changed pattern of internal torsional waves (helioseismology) or the announced fading and magnetic weakening of sunspots. Methods: Based on a statistical analysis of detailed sunspot properties over the last 24 years, we complete the picture with new evidence of a strong global deficit of the smallest sunspots starting around 2000, in order to answer the question: are all sunspots about to disappear? Results: This global scale-dependent change in sunspot properties is confirmed to be real and not due to uncontrolled biases in some of the indices. It can also explain the recent discrepancies between solar indices by their different sensitivities to small and weak magnetic elements (small spots). The International Sunspot Index Ri, based on unweighted sunspot counts, proved to be particularly sensitive to this particular small-scale solar evolution. Conclusions: Our results and interpretation show the necessity to look backwards in time, more than 80 years ago. Indeed, the Sun seems to be actually returning to a past and hardly explored activity regime ending before the 1955-1995 Grand Maximum, which probably biased our current space-age view of solar activity.

  10. 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.

  11. Chemical-dynamical response to the 11-year solar cycle in a transient CCM simulation of the past

    NASA Astrophysics Data System (ADS)

    Kubin, A.; Langematz, U.; Baumgärtner, A.; Brühl, Ch.

    2009-04-01

    We present results from a CCMVal REF1 simulation performed with the ECHAM5/MESSy model system. The time period 1960 to 2000 was simulated using the model in T42L90 resolution. The model was forced by observed sea surface temperatures and spectrally resolved solar irradiances as well as greenhouse gases and ozone depleting substances according to the CCMVal recommendations. The QBO was internally generated and major volcanic eruptions were included. A state-of-the-art multiple linear regression model is used for the analysis. Emphasis is laid on the 11-year solar signal in chemical and dynamical variables such as ozone volume mixing ratio and related radiative heating, temperature and zonal wind. Moreover, the solar impact on planetary wave propagation and the residual circulation is examined as well as the transfer of the solar signal from the stratosphere to the troposphere. The solar influence on variability patterns as the Arctic Oscillation or the North Atlantic Oscillation is studied and we investigate furthermore the impact on tropical precipitation. The results are compared with observations.

  12. An Estimate of the Size and Shape of Sunspot Cycle 24 Based on its Early Cycle Behavior using the Hathaway-Wilson-Reichmann Shape-Fitting Function

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2011-01-01

    On the basis of 12-month moving averages (12-mma) of monthly mean sunspot number (R), sunspot cycle 24 had its minimum amplitude (Rm = 1.7) in December 2008. At 12 mo past minimum, R measured 8.3, and at 18 mo past minimum, it measured 16.4. Thus far, the maximum month-to-month rate of rise in 12-mma values of monthly mean sunspot number (AR(t) max) has been 1.7, having occurred at elapsed times past minimum amplitude (t) of 14 and 15 mo. Compared to other sunspot cycles of the modern era, cycle 24?s Rm and AR(t) max (as observed so far) are the smallest on record, suggesting that it likely will be a slow-rising, long-period sunspot cycle of below average maximum amplitude (RM). Supporting this view is the now observed relative strength of cycle 24?s geomagnetic minimum amplitude as measured using the 12-mma value of the aa-geomagnetic index (aam = 8.4), which also is the smallest on record, having occurred at t equals 8 and 9 mo. From the method of Ohl (the inferred preferential association between RM and aam), one predicts RM = 55 +/- 17 (the ?1 se prediction interval) for cycle 24. Furthermore, from the Waldmeier effect (the inferred preferential association between the ascent duration (ASC) and RM) one predicts an ASC longer than 48 mo for cycle 24; hence, maximum amplitude occurrence should be after December 2012. Application of the Hathaway-Wilson-Reichmann shape-fitting function, using an RM = 70 and ASC = 56 mo, is found to adequately fit the early sunspot number growth of cycle 24.

  13. A Comparison of Solar Cycle Variations in the Equatorial Rotation Rates of the Sun's Subsurface, Surface, Corona, and Sunspot Groups

    NASA Astrophysics Data System (ADS)

    Javaraiah, J.

    2013-10-01

    Using the Solar Optical Observing Network (SOON) sunspot-group data for the period 1985 - 2010, the variations in the annual mean equatorial-rotation rates of the sunspot groups are determined and compared with the known variations in the solar equatorial-rotation rates determined from the following data: i) the plasma rotation rates at 0.94R⊙,0.95R⊙,…,1.0R⊙ measured by the Global Oscillation Network Group (GONG) during the period 1995 - 2010, ii) the data on the soft-X-ray corona determined from Yohkoh/SXT full-disk images for the years 1992 - 2001, iii) the data on small bright coronal structures (SBCS) that were traced in Solar and Heliospheric Observatory (SOHO)/EIT images during the period 1998 - 2006, and iv) the Mount Wilson Doppler-velocity measurements during the period 1986 - 2007. A large portion (up to ≈ 30∘ latitude) of the mean differential-rotation profile of the sunspot groups lies between those of the internal differential-rotation rates at 0.94R⊙ and 0.98R⊙. The variation in the yearly mean equatorial-rotation rate of the sunspot groups seems to be lagging behind that of the equatorial-rotation rate determined from the GONG measurements by one to two years. The amplitude of the GONG measurements is very small. The solar-cycle variation in the equatorial-rotation rate of the solar corona closely matches that determined from the sunspot-group data. The variation in the equatorial-rotation rate determined from the Mount Wilson Doppler-velocity data closely resembles the corresponding variation in the equatorial-rotation rate determined from the sunspot-group data that included the values of the abnormal angular motions (> |3∘| day-1) of the sunspot groups. Implications of these results are pointed out.

  14. 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

  15. The Recent Rejuvenation of the Sun's Large-scale Magnetic Field: A Clue for Understanding Past and Future Sunspot Cycles

    NASA Astrophysics Data System (ADS)

    Sheeley, N. R., Jr.; Wang, Y.-M.

    2015-08-01

    The quiet nature of sunspot cycle 24 was disrupted during the second half of 2014 when the Sun’s large-scale field underwent a sudden rejuvenation: the solar mean field reached its highest value since 1991, the interplanetary field strength doubled, and galactic cosmic rays showed their strongest 27-day modulation since neutron-monitor observations began in 1957; in the outer corona, the large increase of field strength was reflected by unprecedentedly large numbers of coronal loops collapsing inward along the heliospheric current sheet. Here, we show that this rejuvenation was not caused by a significant increase in the level of solar activity as measured by the smoothed sunspot number and CME rate, but instead was caused by the systematic emergence of flux in active regions whose longitudinal distribution greatly increased the Sun’s dipole moment. A similar post-maximum increase in the dipole moment occurred during each of the previous three sunspot cycles, and marked the start of the declining phase of each cycle. We note that the north-south component of this peak dipole moment provides an early indicator of the amplitude of the next cycle, and conclude that the amplitude of cycle 25 may be comparable to that of cycle 24, and well above the amplitudes obtained during the Maunder Minimum.

  16. Comparison of the Variations of Sunspot Number, Number of Sunspot Groups, and Sunspot Area, 1875 -2013

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2014-01-01

    Examined are the yearly variations and ratios of sunspot number, the number of sunspot groups, and the total corrected sunspot area for the interval 1875-2013. While yearly sunspot number independently correlates strongly (r = 0.98) with the yearly number of sunspot groups (y = -2 + 11.99x) and the total corrected sunspot area (y = 5 + 0.059x), the strongest correlation (Ry12 = 0.99) is the one based on the bivariate fit of sunspot number against the combined variations of the number of sunspot groups and sunspot area (y = 1 + 5.88x1 + 0.031x2, where y refers to sunspot number, x1 refers to the number of sunspot groups, and x2 refers to the sunspot area). While all cycle minima based on the bivariate fit are concurrent with the observed minimum in sunspot number, cycle maxima are sometimes found to differ. For sunspot cycles 12, 19, 20, and 23, cycle maximum is inferred to have occurred in 1884, 1958, 1970, and 2002, respectively, rather than in 1883, 1957, 1968, and 2000, based on the observed sunspot number. Also, cycle 19's maximum amplitude based on observed sunspot number seems too high in comparison to that found using the bivariate fit. During the 139-year interval 1875-2013, the difference between the observed and predicted sunspot number based on the bivariate fit is <1 standard error of estimate (se) (<6.4) for 111 years, between 1 and <2 se (6.4 to <12.8) for 28 years, and =2 se (=12.8) for only 4 years, these years being 1957 (16.6), 1978 (-15.8), 1980 (23), and 1982 (-16.3). For sunspot cycle 24, the difference between observed and predicted values has been only -0.7 and 3.2 (=0.5 se).

  17. Identification of Gleissberg Cycles and a Rising Trend in a 315-Year-Long Series of Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Le Mouël, Jean-Louis; Lopes, Fernand; Courtillot, Vincent

    2017-03-01

    We show in this short note that the method of singular spectrum analysis (SSA) is able to clearly extract a strong, clean, and clear component from the longest available sunspot (International Sunspot Number, ISN) time series (1700 - 2015) that cannot be an artifact of the method and that can be safely identified as the Gleissberg cycle. This is not a small component, as it accounts for 13% of the total variance of the total original signal. Almost three and a half clear Gleissberg cycles are identified in the sunspot number series. Four extended solar minima (XSM) are determined by SSA, the latest around 2000 (Cycle 23/24 minimum). Several authors have argued in favor of a double-peaked structure for the Gleissberg cycle, with one peak between 55 and 59 years and another between 88 and 97 years. We find no evidence of the former: solar activity contains an important component that has undergone clear oscillations of ≈90 years over the past three centuries, with some small but systematic longer-term evolution of "instantaneous" period and amplitude. Half of the variance of solar activity on these time scales can be satisfactorily reproduced as the sum of a monotonous multi-secular increase, a ≈90-year Gleissberg cycle, and a double-peaked (≈10.0 and 11.0 years) Schwabe cycle (the sum amounts to 46% of the total variance of the signal). The Gleissberg-cycle component definitely needs to be addressed when attempting to build dynamo models of solar activity. The first SSA component offers evidence of an increasing long-term trend in sunspot numbers, which is compatible with the existence of the modern grand maximum.

  18. January-february Tropospheric Climate for the Northern Hemisphere and the 11-year Solar Cycle, the QBO and the Southern Oscillation

    NASA Technical Reports Server (NTRS)

    Barnston, Anthony G.; Livezey, Robert E.

    1990-01-01

    Examined here is a recently discovered association between the 11-year solar cycle and the atmosphere that is most easily detectable when the two phases of the Quasi-biennial Oscillation (QBO) are considered individually rather than pooled. The influence of the Southern Oscillation (SO) for either of the two QBO phases is then combined with that of the solar cycle in the form of two-predictor multiple regression. The strong and well-defined relationship between the 11-year 10.7 cm solar flux cycle and the lower troposphere Northern Hemisphere January-February climate for QBO phase-stratified samples (van Loon and Labitzke 1988, Barnston and Livezey 1989) failed for the west QBO phase in 1989. Here, the opposing 1989 event is explained, at least in part, on the basis of the phase of the SO (the cold tropical Pacific SST event of 1988 to 1989). It is demonstrated that both the SO and the solar flux have moderate and quasi-independent correlations with the climate over certain regions, and where there is strong overlap they can work either in harmony or in opposition. In 1989 in North America the influences of the SO and the flux conflicted to an unprecedented extent, and the SO was the controlling influence in most regions of the continent (western Canada being one exception). The 1989 event draws attention to the smallness of the QBO phase-stratified samples and the still more serious holes in the two-dimensional sample space of flux and SO when both factors are viewed as predictors within one QBO phase.

  19. Estimating sunspot number

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.; Reichmann, E. J.; Teuber, D. L.

    1984-01-01

    An empirical method is developed to predict certain parameters of future solar activity cycles. Sunspot cycle statistics are examined, and curve fitting and linear regression analysis techniques are utilized.

  20. Merging Sunspots

    NASA Video Gallery

    One core area of Sunspot 1117 emerged, and then edged over and merged with another core area over three days (Oct. 25-27, 2010) to form a much larger, active sunspot region. Portions of sunspot gro...

  1. Long-term variation of statistical properties of sunspot field strengths and their relation to the characteristics of solar cycles in 1917-2013

    NASA Astrophysics Data System (ADS)

    Tlatova, Kseniya; Pevtsov, Alexei; Tlatov, Andrey; Vasilieva, Valeria; Kalevi Mursula

    We use the digitized sunspot daily drawings from the Mount Wilson Observatory (MWO) from 1917—2013 to study the long-term variations in sunspot magnetic fields. Tabulated data include the heliographic coordinates, area and magnetic field strength of all sunspots on solar disk. Sunspot field strengths exhibit several trends, which can be of instrumental or truly solar in its nature. For example, in depth analysis of the sunspot field strength and the sunspot areas indicates long-term changes in the observing system at the MWO, when systematically larger number of measurements in sub-features (e.g., multiple umbrae) was made beginning mid-20th century. The final data set is used to study several properties of active regions including difference (in field strength and area) between leading and following sunspots, the orientation of magnetic field in sunspots and pores relative to vertical direction, and the Hale (polarity) and Joy (tilt) laws over the period of about ten solar cycles.

  2. Middle Atmosphere Response to Different Descriptions of the 11-Year Solar Cycle in Spectral Irradiance in a Chemistry-Climate Model

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    The 11-year solar cycle in solar spectral irradiance (SSI) inferred from measurements by the SOlar Radiation & Climate Experiment (SORCE) suggests a much larger variation in the ultraviolet than previously accepted. We present middle atmosphere ozone and temperature responses to the solar cycles in SORCE SSI and the ubiquitous Naval Research Laboratory (NRL) SSI reconstruction using the Goddard Earth Observing System chemistry-climate model (GEOS CCM). The results are largely consistent with other recent modeling studies. The modeled ozone response is positive throughout the stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with respect to total solar irradiance above 45 km. The modeled responses in total ozone are similar to those derived from satellite and ground-based measurements, 3-6 Dobson Units per 100 units of 10.7-cm radio flux (F10.7) in the tropics. The peak zonal mean tropical temperature response 50 using the SORCE SSI is nearly 2 K per 100 units 3 times larger than the simulation using the NRL SSI. The GEOS CCM and the Goddard Space Flight Center (GSFC) 2-D coupled model are used to examine how the SSI solar cycle affects the atmosphere through direct solar heating and photolysis processes individually. Middle atmosphere ozone is affected almost entirely through photolysis, whereas the solar cycle in temperature is caused both through direct heating and photolysis feedbacks, processes that are mostly linearly separable. Further, the net ozone response results from the balance of ozone production at wavelengths less than 242 nm and destruction at longer wavelengths, coincidentally corresponding to the wavelength regimes of the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) and Spectral Irradiance Monitor (SIM) on SORCE, respectively. A higher wavelength-resolution analysis of the spectral response could allow for a better prediction of the

  3. A dynamo theory prediction for solar cycle 22 - Sunspot number, radio flux, exospheric temperature, and total density at 400 km

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Hedin, A. E.

    1984-01-01

    Using the 'dynamo theory' method to predict solar activity, a value for the smoothed sunspot number of 109 + or - 20 is obtained for solar cycle 22. The predicted cycle is expected to peak near December, 1990 + or - 1 year. Concommitantly, F(10.7) radio flux is expected to reach a smoothed value of 158 + or - 18 flux units. Global mean exospheric temperature is expected to reach 1060 + or - 50 K and global total average total thermospheric density at 400 km is expected to reach 4.3 x 10 to the -15th gm/cu cm + or - 25 percent.

  4. A dynamo theory prediction for solar cycle 22: Sunspot number, radio flux, exospheric temperature, and total density at 400 km

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Hedin, A. E.

    1986-01-01

    Using the dynamo theory method to predict solar activity, a value for the smoothed sunspot number of 109 + or - 20 is obtained for solar cycle 22. The predicted cycle is expected to peak near December, 1990 + or - 1 year. Concommitantly, F(10.7) radio flux is expected to reach a smoothed value of 158 + or - 18 flux units. Global mean exospheric temperature is expected to reach 1060 + or - 50 K and global total average total thermospheric density at 400 km is expected to reach 4.3 x 10 to the -15th gm/cu cm + or - 25 percent.

  5. Predicting the Size of Sunspot Cycle 24 on the Basis of Single- and Bi-Variate Geomagnetic Precursor Methods

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2009-01-01

    Examined are single- and bi-variate geomagnetic precursors for predicting the maximum amplitude (RM) of a sunspot cycle several years in advance. The best single-variate fit is one based on the average of the ap index 36 mo prior to cycle minimum occurrence (E(Rm)), having a coefficient of correlation (r) equal to 0.97 and a standard error of estimate (se) equal to 9.3. Presuming cycle 24 not to be a statistical outlier and its minimum in March 2008, the fit suggests cycle 24 s RM to be about 69 +/- 20 (the 90% prediction interval). The weighted mean prediction of 11 statistically important single-variate fits is 116 +/- 34. The best bi-variate fit is one based on the maximum and minimum values of the 12-mma of the ap index; i.e., APM# and APm*, where # means the value post-E(RM) for the preceding cycle and * means the value in the vicinity of cycle minimum, having r = 0.98 and se = 8.2. It predicts cycle 24 s RM to be about 92 +/- 27. The weighted mean prediction of 22 statistically important bi-variate fits is 112 32. Thus, cycle 24's RM is expected to lie somewhere within the range of about 82 to 144. Also examined are the late-cycle 23 behaviors of geomagnetic indices and solar wind velocity in comparison to the mean behaviors of cycles 2023 and the geomagnetic indices of cycle 14 (RM = 64.2), the weakest sunspot cycle of the modern era.

  6. Coupling and Correlation-analysis Between the Northern and Southern Hemispheres' Solar Cycle Features based on Sunspot Area Data

    NASA Astrophysics Data System (ADS)

    Wilson, W. N.; Dikpati, M.

    2014-12-01

    Vast literature on Babcock-Leighton flux-transport dynamo models indicate that the sunspot activity cycles in the Northern and Southern hemispheres are primarily decoupled about the equator and are independent of each other. However, we find from the analysis of long-term sunspot area data from 1875 to 2013 that the two hemispheres continuously attempt to couple about the equator. If we define the coupling line as the line where the sunspot area of the two hemispheres is the same on the plot of North versus South spot-area, we find that the two hemispheres' spot-area tend to fall on the coupling line over a very long period of time, despite their short-term traversal away from the coupling line. This indicates that there must be some underlying process inside the Sun's interior which is causing this coupling. Further analysis of the features, such as rise and decay times of solar cycles, minima and peak amplitudes, reveal that the solar cycles normally follow a saw-tooth pattern with a fast rise and slow fall, as noted before. Most interestingly, we find that rise-time in one hemisphere correlates with minima-amplitude of the other hemisphere, but anti-correlates with that of the same hemisphere. We speculate that this happens because the fast rise of a cycle can annihilate the opposite-hemisphere's flux faster, leading to a lower minima-amplitude. By contrast, the peak of a cycle does not have much influence on minima-amplitude of the opposite hemisphere. We are investigating the physics behind these features through dynamo simulations.

  7. 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.

  8. Periodogram analysis of sunspot numbers and the relation with solar activities

    NASA Technical Reports Server (NTRS)

    Hady, Ahmed A.

    1995-01-01

    The time series of average monthly sunspot numbers during 1900-1992 is studied by using power spectral analysis. This prediction method is used to study the sunspot periodicities relations between its, and with the other periodicities by solar activities. There are periodicities (between few days and 5 years) overwhelm on the mean solar cycle. ( 11 year cycle). These periodicities have the same relation with variations of solar constant and solar radiation reaching the Earth's atmosphere in the last solar cycle. These periods are related to the solar magnetic activity and to the modulation of solar features due to solar rotation.

  9. Trend estimation and univariate forecast of the sunspot numbers: Development and comparison of ARMA, ARIMA and Autoregressive Neural Network models

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Surajit; Jhajharia, Deepak; Chattopadhyay, Goutami

    2011-07-01

    In the present study, a prominent 11-year cycle, supported by the pattern of the autocorrelation function and measures of Euclidean distances, in the mean annual sunspot number time series has been observed by considering the sunspot series for the duration of 1749 to 2007. The trend in the yearly sunspot series, which is found to be non-normally distributed, is examined through the Mann-Kendall non-parametric test. A statistically significant increasing trend is observed in the sunspot series in annual duration. The results indicate that the performance of the autoregressive neural network-based model is much better than the autoregressive moving average and autoregressive integrated moving average-based models for the univariate forecast of the yearly mean sunspot numbers.

  10. The theory of sunspots

    NASA Technical Reports Server (NTRS)

    Thomas, John H.; Weiss, Nigel O.

    1992-01-01

    This review covers the present state of our theoretical understanding of the physics of sunspots, along with the principal observational results that need to be explained. The topics covered range from the detailed structure of an individual sunspot to the broad connection between sunspots and the global solar magnetic field and the solar cycle. Our aim is to give a critical discussion of the theoretical ideas and models without presenting mathematical details. After outlining the historical development of the basic concepts associated with the magnetohydrodynamic theory of sunspots, we discuss recent treatments of their properties and structure, placing special emphasis on developments that have occurred within the last ten years. There have been remarkable improvements in the theoretical modelling of sunspots, led by new ideas and by more elaborate and realistic numerical simulations. At the same time, new observations have raised new theoretical questions or caused old ones to be reconsidered. In particular, measurements of oscillations in and around sunspots have opened up the new field of sunspot seismology, while recent high-resolution observations have forced us to rethink the structure of a sunspot penumbra.

  11. Structure of the Heliotail from Interstellar Boundary Explorer Observations: Implications for the 11-year Solar Cycle and Pickup Ions in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Zirnstein, E. J.; Heerikhuisen, J.; Zank, G. P.; Pogorelov, N. V.; Funsten, H. O.; McComas, D. J.; Reisenfeld, D. B.; Schwadron, N. A.

    2017-02-01

    Interstellar Boundary Explorer (IBEX) measurements of energetic neutral atoms (ENAs) from the heliotail show a multi-lobe structure of ENA fluxes as a function of energy between ∼0.71 and 4.29 keV. Below ∼2 keV, there is a single structure of enhanced ENA fluxes centered near the downwind direction. Above ∼2 keV, this structure separates into two lobes, one north and one south of the solar equatorial plane. ENA flux from these two lobes can be interpreted as originating from the fast solar wind (SW) propagating through the inner heliosheath (IHS). Alternatively, a recently published model of the heliosphere suggests that the heliotail may split into a “croissant-like” shape, and that such a geometry could be responsible for the heliotail ENA feature. Here we present results from a time-dependent simulation of the heliosphere that produces a comet-like heliotail, and show that the 11-year solar cycle leads to the formation of ENA lobes with properties remarkably similar to those observed by IBEX. The ENA energy at which the north and south lobes appear suggests that the pickup ion (PUI) temperature in the slow SW of the IHS is ∼107 K. Moreover, we demonstrate that the extinction of PUIs by charge-exchange is an essential process required to create the observed global ENA structure. While the shape and locations of the ENA lobes as a function of energy are well reproduced by PUIs that cross the termination shock, the results appear to be sensitive to the form of the distribution of PUIs injected in the IHS.

  12. The possible mechanism of the "stratospheric bridge" modulation by the Pacific Decadal Oscillation in early winter and the QBO, 11-year solar cycle in late winter

    NASA Astrophysics Data System (ADS)

    Jadin, Evgeny; Wei, Ke; Chen, Wen; Wang, Lin

    Questions of the interannual variations of the extra-tropical stratospheric dynamics, its rela-tionship with the sea surface temperature (SST) anomalies in the North Pacific (Pacific Decadal Oscillation -PDO) in early winter (November-December), Quasi-Biennial Oscillation (QBO) (Holton-Tan relations), a decadal modulation by the 11-year Solar Cycle (SC) (Labitzke, van Loon -LvL correlations) in late winter (January-February) are discussed. In early winter, the interannual changes of the planetary wave activity define partly the variations of the strato-spheric circulation in subsequent January [Zyulyaeva and Jadin, 2009]. The interannual and decadal variations of the stratospheric wave activity appear to be associated with those of the PDO [Jadin et al. 2009]. A decadal period from the mid-1970s to mid-1990s of the violation of the Holton-Tan (HT) relationship corresponds well to that of the positive PDO phase (anoma-lously cold SSTs in the central North Pacific). Using the NCEP and ERA-40 monthly mean reanalysis datasets, the three-dimensional Eliassen-Palm fluxes are calculated. The results of the analysis of relations between the upward/downward propagation of planetary waves in the lower stratosphere ("stratospheric bridge"), their interaction with the zonal wind and the HT and LvL correlations for January-February are presented. In contrast with early winter, the large role in the wave-zonal flow interaction plays the downward propagation of planetary waves from the stratosphere to the troposphere over Canada and North Atlantic ("stratospheric wave hole") responsible for the sink of the eddy energy from the stratosphere. One can suggest that there are two dominant regimes in the stratosphere-troposphere coupling in late winter: 1) the "ventilation regime" with the strong penetration of planetary waves from the troposphere over north Eurasia and their strong downward propagation over Canada and North Atlantic, and 2) the "blocking regime" with the weak those

  13. 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).

  14. Estimating the Mean Annual Surface Air Temperature at Armagh Observatory, Northern Ireland, and the Global Land-Ocean Temperature Index for Sunspot Cycle 24, the Current Ongoing Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2013-01-01

    As noted by Gray et al., Sir William Herschel was the first to suggest a possible close connection between the Sun and the Earth’s climate. The Sun, being the source of energy that impacts and drives the Earth’s climate system, displays a variety of changes over both short and long term time scales, the most obvious examples being the somewhat regular waxing and waning of sunspots with time (i.e., the sunspot cycle (SC)), first described by Samuel Heinrich Schwabe, a German apothecary and amateur astronomer who observed the Sun from Dessau, Germany, and the now well established variation of the Sun’s irradiance over the SC. Other factors related to the SC have been linked to changes in climate as well. Some of these other factors include the role of cosmic rays and the solar wind (i.e., the geomagnetic cycle) on climate, as well as the apparent close association between trends in global and northern hemispheric temperature and the length of the SC, although some investigators have described the inferred association between climate and, in particular, SC length as now being weak. More recently, Solheim et al. have reported on the relation between SC length and the average temperature in the same and immediately following SC for a number of meteorological stations in Norway and in the North Atlantic region. They noted that while they found no significant trend (correlation) between SC length and the average temperature when measured for the same cycle, in contrast, they found a significant negative trend when SC length was compared with the following cycle’s average temperature. From this observation, they suggested that average northern hemispheric temperature during the present ongoing SC (SC24) will be lower by about 0.9 °C than was seen in SC23 (spanning 1996–2007, based on yearly averages of sunspot number (SSN), and onset for SC24 occurring in 2008). The purpose of this Technical Publication (TP) is to examine the annual variations of the Armagh

  15. Sunspot dynamics

    NASA Technical Reports Server (NTRS)

    Thomas, John H.

    1993-01-01

    This report describes recent results of our theoretical and observational work on dynamical phenomena in sunspots. The overall goal of this research has been a better understanding of the various oscillatory, transient, and steady motions in a sunspot and their relation to the basic structure of the sunspot. The principal topics of the research reported here are the following: (1) sunspot seismology, i.e., the study of the interaction of solar p-modes with a sunspot as a probe of the subsurface structure of a sunspot; (2) local sources of acoustic waves in the solar photosphere; and (3) siphon flows in isolated magnetic flux tubes and their relation to the photospheric Evershed flow and to intense magnetic elements outside of sunspots.

  16. Sunspot dynamics

    NASA Technical Reports Server (NTRS)

    Thomas, John H.

    1990-01-01

    The goal of this research was the understanding of the various oscillatory, transient, and quasi-steady motions in sunspots and the basic structure of a sunspot. The research involved both theoretical modeling (based on thermohydrodynamic theory) and observations of dynamical phenomena in sunspots. The principal topics of the research were sunspot seismology (the interaction of solar p-modes with a sunspot as a probe of the subsurface structure of a sunspot); three minute umbral oscillations and their relation to the structure of the umbral atmosphere; siphon flows in isolated magnetic flux tubes and their relation to the photospheric Evershed flow and to intense magnetic elements outside of sunspots; and more general theoretical work on magneto-atmospheric waves. Here, a summary of results is given.

  17. THE RECENT REJUVENATION OF THE SUN’S LARGE-SCALE MAGNETIC FIELD: A CLUE FOR UNDERSTANDING PAST AND FUTURE SUNSPOT CYCLES

    SciTech Connect

    Sheeley, N. R. Jr.; Wang, Y.-M.

    2015-08-20

    The quiet nature of sunspot cycle 24 was disrupted during the second half of 2014 when the Sun’s large-scale field underwent a sudden rejuvenation: the solar mean field reached its highest value since 1991, the interplanetary field strength doubled, and galactic cosmic rays showed their strongest 27-day modulation since neutron-monitor observations began in 1957; in the outer corona, the large increase of field strength was reflected by unprecedentedly large numbers of coronal loops collapsing inward along the heliospheric current sheet. Here, we show that this rejuvenation was not caused by a significant increase in the level of solar activity as measured by the smoothed sunspot number and CME rate, but instead was caused by the systematic emergence of flux in active regions whose longitudinal distribution greatly increased the Sun’s dipole moment. A similar post-maximum increase in the dipole moment occurred during each of the previous three sunspot cycles, and marked the start of the declining phase of each cycle. We note that the north–south component of this peak dipole moment provides an early indicator of the amplitude of the next cycle, and conclude that the amplitude of cycle 25 may be comparable to that of cycle 24, and well above the amplitudes obtained during the Maunder Minimum.

  18. 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

  19. Approximation of periodicity in sunspot formation of and prediction of the 25th cycle

    NASA Astrophysics Data System (ADS)

    Roshchina, E. M.; Sarychev, A. P.

    2015-12-01

    The empirical parameters of functions approximating solar activity cycles 8-23 are used. These parameters show the position of the cycle on the time axis (the start time) and its shape, which is characterized by the extension along the time axes and activity index. A statistical connections was found between two shape parameters of the cycle (the so-called Waldmeier effect) and between the extension of the cycle growth branch and the start time of the following cycle. A connection between the parameters of the given and future cycles has been obtained for a function approximating the "secular" variations in the cycle amplitude. The aforementioned empirical relationships can be stated in the form of three equations that contain the parameters of the current and future cycles. Solving this system, we obtain estimates for three parameters of the function approximating the next cycle. For the 25th cycle, it was found that the maximum of the smoothed Wolf number 116 is expected in March/April 2026; the duration of the activity growth branch is 4.16 years.

  20. Using the Boundary Conditions of Sunspots as a Technique for Monitoring Solar Luminosity Variations

    NASA Technical Reports Server (NTRS)

    Hoyt, Douglas V.

    1990-01-01

    Recent satellite observations of the solar total irradiance confirm that it is varying at least on the 11 year time scale. Both blocking by sunspots and re-emission by faculae are components in this variation, but changes in the temperature of the solar photosphere may also be a contributing component. The satellite observations are as yet of insufficient length to answer the question of whether the sun is varying in luminosity on time scales longer than the 11 year sunspot cycle. Examined here are proxy methods of re-constructing these longer term luminosity variations, with an examination of secular changes in sunspot structure as one tool. Solar rotation changes and solar diameter changes are other parameters which may reveal information about solar luminosity variations. All three variables give remarkably similar conclusions. Over the last century the Earth's surface temperatures and the structure of sunspots have varied in a parallel manner. It is hypothesized that sunspots have varied in a convective medium which itself is varying over long time periods. These variations in convective strength alter the boundary conditions on sunspots and hence cause their structure to vary. Simultaneous with the variations in convective strength, the solar luminosity will vary as well. This, in turn, leads to changes in the climate of the Earth. Variations in solar diameter and solar rotation support the hypothesis that solar luminosity has varied over the last century and reached a peak around 1925 to 1935. This evidence is reviewed along with a possible model of why sunspot structure may provide a good proxy measure of solar luminosity changes.

  1. 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.

  2. 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.

  3. Sunspots, El Niño, and the levels of Lake Victoria, East Africa

    NASA Astrophysics Data System (ADS)

    Stager, J. Curt; Ruzmaikin, Alexander; Conway, Declan; Verburg, Piet; Mason, Peter J.

    2007-08-01

    An association of high sunspot numbers with rises in the level of Lake Victoria, East Africa, has been the focus of many investigations and vigorous debate during the last century. In this paper, we show that peaks in the ~11-year sunspot cycle were accompanied by Victoria level maxima throughout the 20th century, due to the occurrence of positive rainfall anomalies ~1 year before solar maxima. Similar patterns also occurred in at least five other East African lakes, which indicates that these sunspot-rainfall relationships were broadly regional in scale. Although irradiance fluctuations associated with the sunspot cycle are weak, their effects on tropical rainfall could be amplified through interactions with sea surface temperatures and atmospheric circulation systems, including ENSO. If this Sun-rainfall relationship persists in the future, then sunspot cycles can be used for long-term prediction of precipitation anomalies and associated outbreaks of insect-borne disease in much of East Africa. In that case, unusually wet rainy seasons and Rift Valley Fever epidemics should occur a year or so before the next solar maximum, which is expected to occur in 2011-2012 AD.

  4. Prediction of ionospheric scintillation using neural network over East African region during ascending phase of sunspot cycle 24

    NASA Astrophysics Data System (ADS)

    Taabu, S. D.; D'ujanga, F. M.; Ssenyonga, T.

    2016-04-01

    VHF and GPS-SCINDA receivers located both at Nairobi (36.8°E, 1.3°S) in Kenya and at Kampala (32.57°E, 0.335°N) in Uganda were used to investigate ionospheric scintillation and forecast scintillations of a few hundred meter-scale irregularities associated with equatorial ionospheric irregularities for the period 2011 and 2012. VHF scintillations was characterized by long duration of activity and slow fading that lasted till early morning hours (05:00 LT). Furthermore, different percentage occurrence of scintillations in some months were observed, but found that weak scintillation (0.2 sunspot number. The enhancement of pre-midnight scintillations during magnetically disturbed and quiet periods was also observed and found to be seasonal and local time dependent. An attempt was made to develop a model of percentage occurrence of scintillations for the ascending phase of solar cycle 24 using neural network and the modeled data for the occurrence of scintillations was found to match well with original data.

  5. Evolutive Spectral Analysis of Sunspot Data over the past 300 Years

    NASA Astrophysics Data System (ADS)

    Berger, A.; Melice, J. L.; van der Mersch, I.

    1990-04-01

    We analyse the series of the Wolf sunspot number in the frequency domain to determine the dimension of the solar cycle system by using the properties of its strange attractor and to study the stability in time of this dimensionality and of the main quasi-periodicities. The two classical methods of time series analysis, Fourier harmonic and Blackman-Tukey spectral analysis, have been applied first to the series of the annual Wolf sunspot numbers to determine its overall character. To detect stationarity, periodic regression based upon the three most statistically significant quasi-periods and especially a moving form the maximum entropy spectrum analysis (MESA) have been used. Both analyses show a splitting of the 11-year cycle before 1800, when a ± 55-year cycle is dominant, and a single 11-year and ± 100-year peak after 1800. Moreover, these quasi-periods are very sensitive to the time interval over which the analysis is carried out. The reason is that the sunspot numbers constitute a widely non-stationary process, which therefore implies that Fourier techniques are not useful to predict solar activity and must be used as fitting procedure only. The minimum cross-entropy method serves to improve the maximum entropy spectrum. With a good a priori estimate and data containing a low noise level, this method allows the detection of very close peaks and the refinement of the main frequencies; it does not split nor introduce artificial peaks. The Thomson model was also applied for its superior bias control, its excellent leakage resistance and a better statistical information. The same methods were then used to study the 22-year magnetic cycle, which is formed by taking into account the change in polarity of the succeeding 11-year cycle. The moving form of MESA confirms the 22-year cycle to be highly stable in contrast to the instability in the period of the 11-year sunspot series. This suggests the importance of working with the more invariant 22-year magnetic series

  6. Analysis of the sensitivity of the composition and temperature of the stratosphere to the variability of spectral solar radiation fluxes induced by the 11-year cycle of solar activity

    NASA Astrophysics Data System (ADS)

    Smyshlyaev, S. P.; Galin, V. Ya.; Blakitnaya, P. A.; Lemishchenko, A. K.

    2016-01-01

    The sensitivity of the gas composition of the atmosphere and its temperature to the changes in spectral radiation fluxes during the 11-year cycle of solar activity has been analyzed with a chemistry-climate model of the lower and middle atmosphere. For this, the data of satellite measurements acquired in the first decade of the 21st century were used. The results of the model calculations showed that, in addition to the increase in the spectral flux in the absorption bands of molecular oxygen that leads to the growth of the ozone content, the changes in the flux at longer wavelengths are significant for the composition and temperature of the atmosphere. The changes of the ozone destruction rate in different catalytic cycles partly compensate each other; in these processes, the destruction rate increases in the reaction with atomic oxygen, while it decreases in the hydrogen and chlorine cycles.

  7. On Determining the Rise, Size, and Duration Classes of a Sunspot Cycle

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    The behavior of ascent duration, maximum amplitude, and period for cycles 1 to 21 suggests that they are not mutually independent. Analysis of the resultant three-dimensional contingency table for cycles divided according to rise time (ascent duration), size (maximum amplitude), and duration (period) yields a chi-square statistic (= 18.59) that is larger than the test statistic (= 9.49 for 4 degrees-of-freedom at the 5-percent level of significance), thereby, inferring that the null hypothesis (mutual independence) can be rejected. Analysis of individual 2 by 2 contingency tables (based on Fisher's exact test) for these parameters shows that, while ascent duration is strongly related to maximum amplitude in the negative sense (inverse correlation) - the Waldmeier effect, it also is related (marginally) to period, but in the positive sense (direct correlation). No significant (or marginally significant) correlation is found between period and maximum amplitude. Using cycle 22 as a test case, we show that by the 12th month following conventional onset, cycle 22 appeared highly likely to be a fast-rising, larger-than-average-size cycle. Because of the inferred correlation between ascent duration and period, it also seems likely that it will have a period shorter than average length.

  8. Accuracy Analysis for Digitized Sunspot Hand-drawing Records of Purple Mountain Observatory

    NASA Astrophysics Data System (ADS)

    Li, R. Y.; Zhou, T. H.; Ji, K. F.

    2016-05-01

    Sunspot is the most significant feature in solar disk, and the earliest record of the solar activities. It has been systematically observed for about 400 years after the invention of telescopes. The long-term evolution of solar activities, especially the 11 year solar cycle, has been obtained based on these data to a great extent. In recent years, the historical hand-drawing records of sunspot are processed digitally for permanent preserving and computer processing. The hand-drawing records of sunspot will be eventually replaced by the CCD image in the future, therefore it is necessary to evaluate the accuracy of hand-drawing records by comparing them with the CCD image. In this study, 189 digital hand-drawing records of sunspot observed by Purple Mountain Observatory in 2011 are analyzed. The results include: (1) the scanner scale difference between horizontal and vertical directions is 0.2%; (2) the ring of the Sun on the recording paper is not a perfect circle, and the diameter in the east-west direction is 1% shorter than that in the north-south direction; (3) the orientation error of the record paper can reach up to 0.5 degree in scanning. After comparing the sunspot position of hand-drawing records with the simultaneous SDO/HMI (Solar Dynamics Observatory/Helioseismic and Magnetic Imager) images of continuous spectrum by overlapping method, we find that the accuracy of sunspot position in hand-drawing record is about 7 arcsec. There are roughly 3% of the hand-drawing sunspots whose corresponding sunspots in SDO/HMI images can not be found.

  9. Egeson’s (George’s) transtridecadal weather cycling and sunspots

    PubMed Central

    Halberg, F.; Cornélissen, G.; Bernhardt, K.-H.; Sampson, M.; Schwartzkopff, O.; Sonntag, D.

    2011-01-01

    In the late 19th century, Charles Egeson, a map compiler at the Sydney Observatory, carried out some of the earliest research on climatic cycles, linking them to about 33-year cycles in solar activity, and predicted that a devastating drought would strike Australia at the turn of the 20th century. Eduard Brückner and William J. S. Lockyer, who, like Egeson, found similar cycles, with notable exceptions, are also, like the map compiler, mostly forgotten. But the transtridecadal cycles are important in human physiology, economics and other affairs and are particularly pertinent to ongoing discusions of climate change. Egeson’s publication of daily weather reports preceded those officially recorded. Their publication led to clashes with his superiors and his personal life was marked by run-ins with the law and, possibly, an implied, but not proven, confinement in an insane asylum and premature death. We here track what little is known of Egeson’s life and of his bucking of the conventional scientific wisdom of his time with tragic results. PMID:21547003

  10. Characteristics of sunspot longitudinal distribution and their correlation with solar activity in pre-Greenwich data

    NASA Astrophysics Data System (ADS)

    Ivanov, V. G.; Miletsky, E. V.

    2016-12-01

    We study and compare characteristics of the sunspot group latitude distribution in two catalogs: extended Greenwich (1874-2014) and Schwabe (1825-1867) (Arlt et al., 2013). We show that both datasets reveal similar correlations between the latitude and amplitude characteristics of the 11-year cycle: the latitude dispersion correlates with the current activity and the sunspot mean latitude at the cycle's maximum is proportional to its amplitude. This agrees with the conclusions drawn in (Ivanov et al., 2011; Ivanov and Miletsky, 2014) for the Greenwich catalog. We show that the latitude properties of the sunspot distribution are much more tolerant to gaps in observational data than traditional amplitude indices of activity. Therefore, the discovered correlations can be used for estimation of the observation quality and independent normalization of the activity levels in spotty pre-Greenwich data. We exemplified this using the Schwabe catalog. In addition, we show that the first part of the Schwabe data probably contains errors in sunspot latitudes, which lead to overestimation of the sunspot latitude dispersions.

  11. 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.

  12. The Maunder minimum as a secular minimum with non-stopped Sunspot cyclicity

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    One of the most enigmatic features of the solar history is the Maunder minimum (1645-1715). We compare the scatter of amplitudes of the 11-year cycles, according to the new Sunspot Number and Sunspot Group series version 2.0, along with scenario of the Maunder minimum as a period with non-stopped cyclicity. We demonstrate that both amplitude and duration of cycles after the Gleissberg and Maunder minima are similar. Moreover, times of minima and maxima of cycles in the course the Maunder minimum coincide with those during the Gleissberg one, indicating a secular variation. Usefulness of the proxy data within the Maunder minimum is discussed. The scatter of amplitudes and duration of the Schwabe cycles in the past is argued to be comparable with those in the modern epoch.

  13. Sunspot random walk and 22-year variation

    USGS Publications Warehouse

    Love, Jeffrey J.; Rigler, E. Joshua

    2012-01-01

    We examine two stochastic models for consistency with observed long-term secular trends in sunspot number and a faint, but semi-persistent, 22-yr signal: (1) a null hypothesis, a simple one-parameter random-walk model of sunspot-number cycle-to-cycle change, and, (2) an alternative hypothesis, a two-parameter random-walk model with an imposed 22-yr alternating amplitude. The observed secular trend in sunspots, seen from solar cycle 5 to 23, would not be an unlikely result of the accumulation of multiple random-walk steps. Statistical tests show that a 22-yr signal can be resolved in historical sunspot data; that is, the probability is low that it would be realized from random data. On the other hand, the 22-yr signal has a small amplitude compared to random variation, and so it has a relatively small effect on sunspot predictions. Many published predictions for cycle 24 sunspots fall within the dispersion of previous cycle-to-cycle sunspot differences. The probability is low that the Sun will, with the accumulation of random steps over the next few cycles, walk down to a Dalton-like minimum. Our models support published interpretations of sunspot secular variation and 22-yr variation resulting from cycle-to-cycle accumulation of dynamo-generated magnetic energy.

  14. An Analysis of the Sunspot Groups and Flares of Solar Cycle 23

    DTIC Science & Technology

    2012-05-07

    www.ngdc.noaa.gov/nndc/ struts /form?t=102827\\&s=40\\&d=8,470,9. The telescopes from which data were drawn for this study were selected based on the avail...ability of archived data for the years 1997 – 2007. They were: Kandilli, Turkey, Tashkent, Uzbekistan, United States Air Force (USAF) Solar Optical ...Groups and Flares of Solar Cycle 23 113 page http://www.ngdc.noaa.gov/nndc/ struts /form?t=102827\\&s=23\\&d=8,210,9 served as the data base for this

  15. The diurnal, annual and sunspot-cycle variations of ESFm at Huancayo compared with similar variations of spread-F occurrence at other longitudes and latitudes

    NASA Astrophysics Data System (ADS)

    Bowman, G. G.; Mortimer, I. K.

    2009-02-01

    Using the tabulations of spread-F data from ionosonde recordings the diurnal, annual and sunspot-cycle variations of this spread-F occurrence have been investigated for the equatorial station, Huancayo. Both Rz max and Rz min periods have been considered. The analyses suggest that some explanation of these variations can be made by involving two regimes, which have been called Regime A and Regime B. The Regime A is present throughout the night but this distribution is more obvious after midnight. This is because in the post-sunset period Regime B, which is associated with significant height rises, is dominant. The Regime A is the same as for similar distributions in mid-latitudes and is inversely related to sunspot activity. It maximizes in December solstice months. The Regime B is directly related to sunspot activity and maximizes in equinoctial months. Changes associated with the upper atmosphere neutral particle density have been found to be important, particularly for Regime A where an inverse relationship exists. The Regime A Rz min annual distributions reported here for Huancayo have been compared with similar distributions at other longitudes and latitudes.

  16. Hemispheric sunspot unit area: comparison with hemispheric sunspot number and sunspot area

    SciTech Connect

    Li, K. J.; Xiang, N. B.; Qu, Z. N.; Xie, J. L.

    2014-03-01

    The monthly mean northern and southern hemispheric sunspot numbers (SNs) and sunspot areas (SAs) in the time interval of 1945 January to 2012 December are utilized to construct the monthly northern and southern hemispheric sunspot unit areas (SUAs), which are defined as the ratio of hemispheric SA to SN. Hemispheric SUAs are usually found to rise at the beginning and to fall at the ending time of a solar cycle more rapidly, forming a more irregular cycle profile than hemispheric SNs and SAs, although it also presents Schwabe-cycle-like hemispheric SNs and SAs. Sunspot activity (SN, SA, and SUA) is found asynchronously and is asymmetrically distributed in the northern and southern hemispheres, and hemispheric SNs, SAs, and SUAs are not in phase in the two hemispheres. The similarity of hemispheric SNs and SAs is found to be much more obvious than that of hemispheric SUAs and SNs (or SAs), and also for their north-south asymmetry. A notable feature is found for the behavior of the SUA around the minimum time of cycle 24: the SUA rapidly decreases from the cycle maximum value to the cycle minimum value of sunspot cycles 19-24 within just 22 months.

  17. Hurricanes in the Gulf of Mexico and the Caribbean Sea and their relationship with sunspots

    NASA Astrophysics Data System (ADS)

    Rojo-Garibaldi, Berenice; Salas-de-León, David Alberto; Sánchez, Norma Leticia; Monreal-Gómez, María Adela

    2016-10-01

    We present the results of a time series analysis of hurricanes and sunspots occurring from 1749 to 2010. Exploratory analysis shows that the total number of hurricanes is declining. This decline is related to an increase in sunspot activity. Spectral analysis shows a relationship between hurricane oscillation periods and sunspot activity. Several sunspot cycles were identified from the time series analysis.

  18. On the Relationship between Solar Wind Speed, Earthward-Directed Coronal Mass Ejections, Geomagnetic Activity, and the Sunspot Cycle Using 12-Month Moving Averages

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    For 1996 .2006 (cycle 23), 12-month moving averages of the aa geomagnetic index strongly correlate (r = 0.92) with 12-month moving averages of solar wind speed, and 12-month moving averages of the number of coronal mass ejections (CMEs) (halo and partial halo events) strongly correlate (r = 0.87) with 12-month moving averages of sunspot number. In particular, the minimum (15.8, September/October 1997) and maximum (38.0, August 2003) values of the aa geomagnetic index occur simultaneously with the minimum (376 km/s) and maximum (547 km/s) solar wind speeds, both being strongly correlated with the following recurrent component (due to high-speed streams). The large peak of aa geomagnetic activity in cycle 23, the largest on record, spans the interval late 2002 to mid 2004 and is associated with a decreased number of halo and partial halo CMEs, whereas the smaller secondary peak of early 2005 seems to be associated with a slight rebound in the number of halo and partial halo CMEs. Based on the observed aaM during the declining portion of cycle 23, RM for cycle 24 is predicted to be larger than average, being about 168+/-60 (the 90% prediction interval), whereas based on the expected aam for cycle 24 (greater than or equal to 14.6), RM for cycle 24 should measure greater than or equal to 118+/-30, yielding an overlap of about 128+/-20.

  19. Naked sunspots

    NASA Technical Reports Server (NTRS)

    Liggett, M.; Zirin, H.

    1983-01-01

    Naked sunspots are spots seen in H-alpha to be devoid of associated plage. In magnetograms and K-line little if any opposite polarity field is found, and in soft X ray images a blank appears in the region of the spot. In almost all cases studied in which naked spots resulted the spot groups had emerged in unipolar regions of the same polarity as the naked spot. At least half of the naked spots are associated with coronal holes. The naked spots are long-lived and show rotation rates close to the Newton-Nunn curve. Most of the naked spots had bright rims in H-alpha, and the one spot observed to disappear left no trace in the background magnetic field. These spots may be a means by which separation of p from f magnetic polarity occurs.

  20. TEMPORAL STABILITY OF SUNSPOT UMBRAL INTENSITIES: 1986-2012

    SciTech Connect

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

    2013-07-10

    We examine the relative intensity of sunspot umbrae during the period from 1986 to 2012 using photometric images from the San Fernando Observatory. We confirm the presence of a relationship between the mean umbral core intensity and the mean sunspot area, as found in previous studies, and do not find a notable change in this relationship between cycles 22 and 23. We looked for a possible time variation in the sunspot umbral contrast during the 27 yr covering cycles 22, 23, and the rise of cycle 24, and we did not find a significant change. These findings do not indicate that sunspots have become less dark during cycles 23 and 24.

  1. Temporal Stability of Sunspot Umbral Intensities: 1986-2012

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    We examine the relative intensity of sunspot umbrae during the period from 1986 to 2012 using photometric images from the San Fernando Observatory. We confirm the presence of a relationship between the mean umbral core intensity and the mean sunspot area, as found in previous studies, and do not find a notable change in this relationship between cycles 22 and 23. We looked for a possible time variation in the sunspot umbral contrast during the 27 yr covering cycles 22, 23, and the rise of cycle 24, and we did not find a significant change. These findings do not indicate that sunspots have become less dark during cycles 23 and 24.

  2. 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.

  3. 11 -year planetary index of solar activity

    NASA Astrophysics Data System (ADS)

    Okhlopkov, Victor

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

  4. A preliminary analysis on the dependence of the human diseases on the relative number of sunspot.

    NASA Astrophysics Data System (ADS)

    Ma, Yuehua; Song, Yi

    1996-03-01

    On the basis of the solar-terrestrial relations point of view, the paper investigates the influences of solar activities upon the human race. According to the data of Nanjing Hospital for Infectious Diseases, both the curve of the occurrence of various diseases and the relative number of sunspots with time are drawn, and their related coefficients are calculated. The preliminary results show that the incidences of typhus and scarlet fever keep in step with the 11-year cycle of solar activities, they get the maximum at the same year, while other diseases are not definite.

  5. Classroom Demonstration of Sunspots.

    ERIC Educational Resources Information Center

    Callaway, Thomas O.; And Others

    1982-01-01

    An overhead projector, projection screen, and clear tungsten Filament light bulb operated through a dimmer or variac switch are used to demonstrate the fact that black appearance of sunspots is due only to contrast and that sunspots are bright. (SK)

  6. How much more can sunspots tell us about the solar dynamo?

    NASA Astrophysics Data System (ADS)

    Norton, Aimee A.; Jones, Eric H.; Liu, Y.; Hayashi, K.; Hoeksema, J. T.; Schou, Jesper

    2013-07-01

    Sunspot observations inspired solar dynamo theory and continue to do so. Simply counting them established the sunspot cycle and its period. Latitudinal distributions introduced the tough constraint that the source of sunspots moves equator-ward as the cycle progresses. Observations of Hale's polarity law mandated hemispheric asymmetry. How much more can sunspots tell us about the solar dynamo? We draw attention to a few outstanding questions raised by inherent sunspot properties. Namely, how to explain sunspot rotation rates, the incoherence of follower spots, the longitudinal spacing of sunspot groups, and brightness trends within a given sunspot cycle. After reviewing the first several topics, we then present new results on the brightness of sunspots in Cycle 24 as observed with the Helioseismic Magnetic Imager (HMI). We compare these results to the sunspot brightness observed in Cycle 23 with the Michelson Doppler Imager (MDI). Next, we compare the minimum intensities of five sunspots simultaneously observed by the Hinode Solar Optical Telescope Spectropolarimeter (SOT-SP) and HMI to verify that the minimum brightness of sunspot umbrae correlates well to the maximum field strength. We then examine 90 and 52 sunspots in the north and south hemisphere, respectively, from 2010 - 2012. Finally, we conclude that the average maximum field strengths of umbra 40 Carrington Rotations into Cycle 24 are 2690 Gauss, virtually indistinguishable from the 2660 Gauss value observed at a similar time in Cycle 23 with MDI.

  7. Generation of a Solar Cycle of Sunspot Metadata Using the AIA Event Detection Framework - A Test of the System

    NASA Astrophysics Data System (ADS)

    Slater, G. L.; Zharkov, S.

    2008-12-01

    The soon-to-be-launched Solar Dynamics Observatory (SDO) will generate roughly 2 TB of image data per day, far more than previous solar missions. Because of the difficulty of widely distributing this enormous volume of data and in order to maximize discovery and scientific return, a sophisticated automated metadata extraction system is being developed at Stanford University and Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, CA. A key component in this system is the Event Detection System, which will supervise the execution of a set of feature and event extraction algorithms running in parallel, in real time, on all images recorded by the four telescopes of the key imaging instrument, the Atmospheric Imaging Assembly (AIA). The system will run on a beowulf cluster of 160 processors. As a test of the new system, we will run feature extraction software developed under the European Grid of Solar Observatories (EGSO) program to extract sunspot metadata from the 12 year SOHO MDI mission archive of full disk continuum and magnetogram images and also from the TRACE high resolution image archive. Although the main goal will be to test the performance of the production line framework, the resulting database will have applications for both research and space weather prediction. We examine some of these applications and compare the databases generated with others currently available.

  8. Analysis and prediction of sunspot numbers

    SciTech Connect

    Paul, A.K.

    1985-12-01

    An extension of anharmonic frequency analysis (AFA) is used to analyze and extrapolate the sunspot numbers. The higher resolution possible with this new approach in principle permits a better accuracy of the prediction for a given extrapolation range, provided the time series is stationary. The results indicate that the extremas of the sunspot numbers of the next three solar cycles will not exceed a magnitude of 100 significantly.

  9. Analysis and prediction of sunspot numbers

    NASA Astrophysics Data System (ADS)

    Paul, A. K.

    1985-12-01

    An extension of anharmonic frequency analysis (AFA) is used to analyze and extrapolate the sunspot numbers. The higher resolution possible with this new approach in principle permits a better accuracy of the prediction for a given exrapolation range, provided the time series is stationary. The results indicate that the extremas of the sunspot numbers of the next three solar cycles will not exceed a magnitude of 100 significantly.

  10. ON A POSSIBLE EXPLANATION OF THE LONG-TERM DECREASE IN SUNSPOT FIELD STRENGTH

    SciTech Connect

    Nagovitsyn, Yury A.; Pevtsov, Alexei A.; Livingston, William C. E-mail: apevtsov@nso.edu

    2012-10-10

    Recent studies revealed a controversy in long-term variations in sunspot field strengths. On one hand, the sunspot field strengths computed by averaging both large and small sunspots and pores show a gradual decrease over the declining phase of solar Cycle 23 and the rising phase of Cycle 24. On the other hand, the strongest sunspot field strengths demonstrate only solar cycle variations with no long-term decline. Here, we investigate the field strength and area properties of sunspots in an attempt to reconcile the presence of both tendencies in recent sunspot field strength measurements. First, we analyze the data set from Penn and Livingston, and we show that in addition to the previously reported long-term decline, the data show the solar cycle variation when only sunspots with the strongest magnetic fields are included. Next, we investigate the variations in the number of sunspots of different sizes, and we find a negative correlation between the numbers of small and large sunspots. Finally, we show that during the period of 1998-2011, the number of large sunspots gradually decreased, while the number of small sunspots steadily increased. We suggest that this change in the fraction of small and large sunspots (perhaps, due to changes in the solar dynamo) can explain the gradual decline in average sunspot field strength as observed by Penn and Livingston.

  11. Hepatoblastoma in an 11-year-old

    PubMed Central

    Pateva, Irina B.; Egler, Rachel A.; Stearns, Duncan S.

    2017-01-01

    Abstract Rationale: Hepatoblastoma is a rare malignancy. Approximately 100 cases are diagnosed yearly in the United States. The highest incidence occurs in infants and in children younger than 5 years. Cases involving patients older than 5 years are very rare. We describe the case of a patient who was diagnosed with hepatoblastoma at an atypical age of presentation for this type of malignancy. We also performed Ovid MEDLINE search for hepatoblastoma and epidemiology reports occurring in children between the ages of 5 and 18 years. In this article we review the epidemiology and summarize case reports published between 1997 and 2012 of patients with hepatoblastoma, who were older than 5 years. Patient concerns and diagnosis: Our patient is an 11 year old boy with stage IV hepatoblastoma with lung and omental metastases at diagnosis. Interventions: The patient received 7 cycles of chemotherapy following the treatment plan of COG protocol AHEP 0731, off study. He also had tumor resection and omentectomy and achieved complete remission. Outcomes: He later had disease recurrence and after undergoing treatment with different modalities, ultimately died of his disease. Review of SEER program data shows that the incidence of hepatoblastoma in children above the age of 5 years is too infrequent to be calculated. Literature review revealed 13 cases of patients diagnosed at age older than 5 years. Most cases were published due to unusual associations and/or complications. There are no obvious unifying characteristics for these cases, although there may be a slight male preponderance and many patients in this selected series presented with elevated Alpha-fetoprotein. Lessons: The reported case is rare, given the very low incidence of hepatoblastoma outside of infancy. A systematic review of characteristics and outcomes for patients older than 5 years who are enrolled in cooperative group hepatoblastoma trials may reveal important information about the epidemiology and tumor

  12. CORRELATION BETWEEN THE 22-YEAR SOLAR MAGNETIC CYCLE AND THE 22-YEAR QUASICYCLE IN THE EARTH'S ATMOSPHERIC TEMPERATURE

    SciTech Connect

    Qu Weizheng; Zhao Jinping; Huang Fei; Deng Shenggui

    2012-07-15

    According to the variation pattern of the solar magnetic field polarity and its relation to the relative sunspot number, we established the time series of the sunspot magnetic field polarity index and analyzed the strength and polarity cycle characteristics of the solar magnetic field. The analysis showed the existence of a cycle with about a 22-year periodicity in the strength and polarity of the solar magnetic field, which proved the Hale proposition that the 11-year sunspot cycle is one-half of the 22-year solar magnetic cycle. By analyzing the atmospheric temperature field, we found that the troposphere and the stratosphere in the middle latitude of both the northern and southern hemispheres exhibited a common 22-year quasicycle in the atmospheric temperature, which is believed to be attributable to the 22-year solar magnetic cycle.

  13. Solar Variability from 240 to 1750 nm in Terms of Faculae Brightening and Sunspot Darkening from SCIAMACHY

    NASA Astrophysics Data System (ADS)

    Pagaran, J.; Weber, M.; Burrows, J.

    2009-08-01

    The change of spectral decomposition of the total radiative output on various timescales of solar magnetic activity is of large interest to terrestrial and solar-stellar atmosphere studies. Starting in 2002, SCIAMACHY was the first satellite instrument to observe daily solar spectral irradiance (SSI) continuously from 230 nm (UV) to 1750 nm (near-infrared; near-IR). In order to address the question of how much UV, visible (vis), and IR spectral regions change on 27 day and 11 year timescales, we parameterize short-term SSI variations in terms of faculae brightening (Mg II index) and sunspot darkening (photometric sunspot index) proxies. Although spectral variations above 300 nm are below 1% and, therefore, well below the accuracy of absolute radiometric calibration, relative accuracy for short-term changes is shown to be in the per mill range. This enables us to derive short-term spectral irradiance variations from the UV to the near-IR. During Halloween solar storm in 2003 with a record high sunspot area, we observe a reduction of 0.3% in the near-IR to 0.5% in the vis and near-UV. This is consistent with a 0.4% reduction in total solar irradiance (TSI). Over an entire 11 year solar cycle, SSI variability covering simultaneously the UV, vis, and IR spectral regions have not been directly observed so far. Using variations of solar proxies over solar cycle 23, solar cycle spectral variations have been estimated using scaling factors that best matched short-term variations of SCIAMACHY. In the 300-400 nm region, which strongly contributes to TSI solar cycle change, a contribution of 34% is derived from SCIAMACHY observations, which is lower than the reported values from SUSIM satellite data and the empirical SATIRE model. The total UV contribution (below 400 nm) to TSI solar cycle variations is estimated to be 55%.

  14. SOLAR VARIABILITY FROM 240 TO 1750 nm IN TERMS OF FACULAE BRIGHTENING AND SUNSPOT DARKENING FROM SCIAMACHY

    SciTech Connect

    Pagaran, J.; Weber, M.; Burrows, J.

    2009-08-01

    The change of spectral decomposition of the total radiative output on various timescales of solar magnetic activity is of large interest to terrestrial and solar-stellar atmosphere studies. Starting in 2002, SCIAMACHY was the first satellite instrument to observe daily solar spectral irradiance (SSI) continuously from 230 nm (UV) to 1750 nm (near-infrared; near-IR). In order to address the question of how much UV, visible (vis), and IR spectral regions change on 27 day and 11 year timescales, we parameterize short-term SSI variations in terms of faculae brightening (Mg II index) and sunspot darkening (photometric sunspot index) proxies. Although spectral variations above 300 nm are below 1% and, therefore, well below the accuracy of absolute radiometric calibration, relative accuracy for short-term changes is shown to be in the per mill range. This enables us to derive short-term spectral irradiance variations from the UV to the near-IR. During Halloween solar storm in 2003 with a record high sunspot area, we observe a reduction of 0.3% in the near-IR to 0.5% in the vis and near-UV. This is consistent with a 0.4% reduction in total solar irradiance (TSI). Over an entire 11 year solar cycle, SSI variability covering simultaneously the UV, vis, and IR spectral regions have not been directly observed so far. Using variations of solar proxies over solar cycle 23, solar cycle spectral variations have been estimated using scaling factors that best matched short-term variations of SCIAMACHY. In the 300-400 nm region, which strongly contributes to TSI solar cycle change, a contribution of 34% is derived from SCIAMACHY observations, which is lower than the reported values from SUSIM satellite data and the empirical SATIRE model. The total UV contribution (below 400 nm) to TSI solar cycle variations is estimated to be 55%.

  15. Investigations of natural and artificial disturbances in the Earth-ionosphere cavity via VLF radio links for the time span 2009-2015 (sunspot cycle 24)

    NASA Astrophysics Data System (ADS)

    Eichelberger, Hans; Schwingenschuh, Konrad; Besser, B. P.; Prattes, Gustav; Aydogar; Wolbang, Daniel; Rozhnoi, Alexander; Solovieva, Maria; Biagi, Pier Francesco; Boudjada, Mohammed

    2016-07-01

    We focus on natural disturbances of the sub-ionospheric VLF waveguide in the time span 2009 to 2015 (sunspot cycle 24), i.e. variations in amplitude and phase measurements of the radio paths are considered. In particular we're investigating numerous solar flares (up to X-class), geomagnetic storms and substorms, therefore discuss how to discriminate natural from artificial variations between different transmitters and receivers. Meteorological effects could be important [1] and we estimate the possibility to detect the influence of lithospheric sources in the VLF radio links. As part of the VLF multistation network we're using the single receiver mid-latitude station in Graz, Austria. This facility receives up to 12 transmitter simultaneously (frequency range 10-50 kHz), has 20 sec temporal resolution, and is running continuously since 2009 [2]. We obtain the statistics relating VLF amplitude and phase fluctuations with C/M/X-class solar flares, and characterise night time fluctuations in connection with enhanced particle precipitation in the northern latitude path (Iceland transmitter). The statistics is important to improve the quality of seismo-electromagnetic studies. We conclude that for ionospheric perturbations (D-layer), e.g. solar flares, a reliable real time monitoring service can be established. Atmospheric and lithospheric variations are generally difficult to characterise, it's harder to distinguish between natural and man made signals, therefore - as a future outlook - complementary ground and satellite based measurements can deliver valuable additional information for environmental monitoring. References: [1] A. Rozhnoi et al.: Meteorological effects in the lower ionosphere as based on VLF/LF signal observations, Nat. Hazards Earth Syst. Sci., 14, 2671-2679, 2014. [2] K. Schwingenschuh et al.: The Graz seismo-electromagnetic VLF facility, Nat. Hazards Earth Syst. Sci., 11, 1121-1127, 2011.

  16. Origin and Use of the Laplace Distribution in Daily Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Noble, P. L.; Wheatland, M. S.

    2013-02-01

    Recently Pop ( Solar Phys. 276, 351, 2012) identified a Laplace (or double exponential) distribution in the number of days with a given absolute value in the change over a day, in sunspot number, for days on which the sunspot number does change. We show this phenomenological rule has a physical origin attributable to sunspot formation, evolution, and decay, rather than being due to the changes in sunspot number caused by groups rotating onto and off the visible disc. We also demonstrate a simple method to simulate daily sunspot numbers over a solar cycle using the Pop ( Solar Phys. 276, 351, 2012) result, together with a model for the cycle variation in the mean sunspot number. The procedure is applied to three recent solar cycles. We check that the simulated sunspot numbers reproduce the observed distribution of daily changes over those cycles.

  17. Sunspots and Snowfall

    ERIC Educational Resources Information Center

    Starr, Richard R.

    1978-01-01

    Examination of the snowfall and total precipitation data for Rochester, New York, suggests a correlation with sunspot activity. Data from other locations tend to support the thesis, but the ability to predict yearly snowfall or total precipitation amounts from sunspot activity has yet to be developed. (Author/CP)

  18. Acoustic absorption by sunspots

    NASA Technical Reports Server (NTRS)

    Braun, D. C.; Labonte, B. J.; Duvall, T. L., Jr.

    1987-01-01

    The paper presents the initial results of a series of observations designed to probe the nature of sunspots by detecting their influence on high-degree p-mode oscillations in the surrounding photosphere. The analysis decomposes the observed oscillations into radially propagating waves described by Hankel functions in a cylindrical coordinate system centered on the sunspot. From measurements of the differences in power between waves traveling outward and inward, it is demonstrated that sunspots appear to absorb as much as 50 percent of the incoming acoustic waves. It is found that for all three sunspots observed, the amount of absorption increases linearly with horizontal wavenumber. The effect is present in p-mode oscillations with wavelengths both significantly larger and smaller than the diameter of the sunspot umbrae. Actual absorption of acoustic energy of the magnitude observed may produce measurable decreases in the power and lifetimes of high-degree p-mode oscillations during periods of high solar activity.

  19. The 11-year solar radiation rhythm and the North Atlantic Oscillation during the last two centuries

    NASA Astrophysics Data System (ADS)

    Brunck, Heiko; Sirocko, Frank

    2016-04-01

    The study is based on a historical chronology of freezing events in central Europe during the last 230 years (river Rhine (Sirocko et al. 2012), Baltic Sea (Koslowski and Glaser, 1999) and Lake Constance (Dobras, 1983)). These regions display both significant similarities with extremely cold winters in central Germany for the years 1799, 1830, 1895, 1929, 1940, 1942, 1947, 1956 and 1963, as well as regional differences in timing and severity of cold winters. The statistical analysis of all 92 historical freezing events showed that 80 events occurred during a negative NAOwinter phase. The bootstrap test defined the results as extremely significant. To understand the climatic forcing behind the freezing chronology the NAO data set was smoothed by a three point running mean filter and compared with the 11- year cyclicity of the sunspot numbers. A complete NAO cycle can be observed within each solar cycle back to 1960 and from 1820 to 1900. From 1900 to 1960 the correlation between the Sun and NAO was weak. This on/off mode becomes visible only in the smoothed NAO data, when time intervals longer than "normal" weather observations are analysed. Statistical test for the coherence of the entire 230 years are insignificant. However, the relation is highly significant, if only the intervals from 1960 to 2010 and 1830 to 1900 are analysed. The phase correlation can be explained by temperature variations up to +-2.5°C in time series of stratospheric air temperature at 40 km height, where ozone is formed by ultraviolet solar radiation. Advanced analysis of sea surface temperatures from reanalysis data (ECMWF Data Archiv, 2013) between 30° - 40°N and 65° - 75°N indicate similar temperature variations in phase with the solar activity. Consequently, the 11 year solar periodicity is related to various parts of the Earth/Ocean/Atmosphere system and not only to the stratospheric signal. However, the NAO is the dominating mediator to implement a solar component into the

  20. Investigation of the Relationship between Solar Flares and Sunspot Groups

    NASA Astrophysics Data System (ADS)

    Eren, S.; Kilcik, A.

    2017-01-01

    We studied the relationship between X-Ray flare numbers (C, M, and, X class flares) and sunspot counts in four categories (Simple (A + B), Medium (C), Large (D + E + F), and End (H)). All data sets cover the whole Solar Cycle 23 and the ascending and maximum phases of Cycle 24 (1996-2014). Pearson correlation analysis method was used to investigate the degree of relationship between monthly solar flare numbers and sunspot counts observed in different sunspot categories. We found that the C, M, and X class flares have highest correlation with the large group sunspot counts, while the small category does not any meaningful correlation. Obtained correlation coefficients between large groups and C, M, and X class flare numbers are 0.79, 0.74, and 0.4, respectively. Thus, we conclude that the main sources of X-Ray solar flares are the complex/large sunspot groups.

  1. Survey and Merging of Sunspot Catalogs

    NASA Astrophysics Data System (ADS)

    Lefevre, Laure; Clette, Frédéric

    2014-02-01

    In view of the construction of new sunspot-based activity indices and proxies, we conducted a comprehensive survey of all existing catalogs providing detailed parameters of photospheric features over long time intervals. Although there are a fair number of such catalogs, a global evaluation showed that they suffer from multiple limitations: finite or fragmented time coverage, limited temporal overlap between catalogs, and, more importantly, a mismatch in contents and conventions. Starting from the existing material, we demonstrate how the information from parallel catalogs can be merged to form a much more comprehensive record of sunspots and sunspot groups. To do this, we use the uniquely detailed Debrecen Photoheliographic Data (DPD), which is already a composite of several ground-based observatories and of SOHO data, and the USAF/Mount Wilson catalog from the Solar Observing Optical Network (SOON). We also outline our cross-identification method, which was needed to match the non-overlapping solar active-region nomenclature. This proved to be the most critical and subtle step when working with multiple catalogs. This effort, focused here first on the last two solar cycles, should lead to a better central database that collects all available sunspot group parameters to address future solar-cycle studies beyond the traditional sunspot-index time series [ R i].

  2. Modulation Cycles of GCR Diurnal Anisotropy Variation

    NASA Astrophysics Data System (ADS)

    Yi, Y.; Oh, S. Y.

    The diurnal variations of GCR intensity observed by the ground NM stations represent the anisotropic GCR flow at 1 AU. It is generally believed that the variation of the local time of the GCR maximum intensity (phase) has 22-year period of two sunspot cycles. However, there even exists doubt on such anisotropy variation cycle. Those different interpretations come from the lack of enough data since determining the cycle of variation in precision requires data archived over long time of at least two cycles. In order to determine the cycle of GCR anisotropy variation, we carried out the statistical study on the diurnal variation of phase. We examined the 52 years data of Huancayo (Haleakala), 38-year data from Rome, 42-year data from Oulu NM stations. We used new method in determining the yearly mean phase. We applied the F-test to determine the statistically meaningful period of anisotropy phase variation. We found that the coupling coefficients indicating the differences in phase between the NM stations are not constant but dependent on the solar cycle. The phase variation has two components of 22-year and 11-year cycles. The NM station in the high latitude (low cut-off rigidity) shows mainly the 22-year cycle in phase controlled by the diffusion effect with the solar polar magnetic field reversal. However, the lower the latitude of NM station is, the higher contribution from 11-year cycle associated with the solar sunspot cycle. This additional phase variation might be regulated by the drift effect.

  3. The effect of the 11-year solar-cycle on the temperature in the upper-stratosphere and mesosphere: Part II numerical simulations and the role of planetary waves

    NASA Astrophysics Data System (ADS)

    Hampson, J.; Keckhut, P.; Hauchecorne, A.; Chanin, M. L.

    2005-07-01

    Results from mechanistic model simulations have been analysed to examine the effect of the solar cycle, and in particular how the level of planetary wave activity changes the effect of the solar cycle. The model is a stratosphere and mesosphere model with detailed chemical, radiative and dynamical schemes. Planetary waves are initiated at the lowest boundary level of the model, which corresponds to the tropopause height. Model simulations have been carried out in pairs, with one simulation using solar forcing corresponding to solar minimum and the other to solar maximum. The level of lower boundary planetary wave forcing is varied between pairs of model simulations. The difference in temperature signal between the pairs of simulations is presented. The results illustrate the crucial role played by the planetary wave forcing in the solar cycle temperature signal. The solar cycle temperature signal in the tropics and subtropics is about 1 K for all values of wave forcing. However, in the extra-tropics the solar signal varies critically with wave forcing, giving a solar signal as strong as 16 K for intermediate values of wave forcing. Despite some spatial differences, the simulations with a specific wave forcing show good qualitative agreements with observational results presented in the companion paper [Keckhut et al., 2005. Journal of Atmospheric and Solar-Terrestrial Physics, submitted for publication]. Above a critical level of wave activity, the non-linear interaction with the mean flow induces a stratospheric warming and a strong temperature change. The critical wave-forcing amplitude necessary to produce such an event is very sensitive to the initial state of the atmosphere and a small change of the mean wind, due for example to an enhancement of the solar forcing, can generate a large difference in temperature, depending on the level of the wave forcing. The numerical simulations presented here suggest a mechanism by which a small change induced by the solar

  4. Sunspot seismology theory

    NASA Technical Reports Server (NTRS)

    Davila, Joseph M.

    1990-01-01

    Physical mechanisms proposed to explain the absorption of significant p-mode wave power by sunspots are reviewed, and their viability in view of the current knowledge of the scattering process is discussed. It is concluded that there is no satisfactory theoretical model for the absorption of p-modes by sunspots available at present. It is argued that the resonance absorption model is able to obtain the large absorption coefficients observed for nonaxisymmetric perturbations. For axisymmetric perturbations, departures from perfect cylindrical symmetry or the inclusion of a slight twist in the sunspot flux tube may be able to resolve the problem with the absorption of m = 0 wave modes. Other dissipative models, which do not incorporate the background gradient effects inherent in the resonance absorption mechanism, require inconveniently large dissipation coefficients within the sunspot.

  5. The New Sunspot Number: Assembling All Corrections

    NASA Astrophysics Data System (ADS)

    Clette, Frédéric; Lefèvre, Laure

    2016-11-01

    Based on various diagnostics and corrections established in the framework of several Sunspot Number Workshops and described by Clette et al. ( Space Sci. Rev. 186, 35, 2014), we now assembled all separately derived corrections to produce a new standard version of the reference sunspot-number time series. We explain here the three main corrections and the criteria used to choose a final optimal version of each correction factor or function, given the available information and published analyses. We then discuss the differences between the new corrected series and the original sunspot number, including the disappearance of any significant rising secular trend in the solar-cycle amplitudes after this recalibration. We also introduce the new version management scheme now implemented at the World Data Center Sunspot Index and Long-term Solar Observations (WDC-SILSO), which reflects a major conceptual transition: beyond the rescaled numbers, this first revision of the sunspot number also transforms the former static data archive into a living observational series open to future improvements.

  6. On the insignificance of Herschel's sunspot correlation

    USGS Publications Warehouse

    Love, Jeffrey J.

    2013-01-01

    We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is “statistically significant.” On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are “insignificant.” Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

  7. Flare-production potential associated with different sunspot groups

    NASA Astrophysics Data System (ADS)

    Eren, S.; Kilcik, A.; Atay, T.; Miteva, R.; Yurchyshyn, V.; Rozelot, J. P.; Ozguc, A.

    2017-02-01

    In this study, we analysed different types (C, M, and X classes) of X-ray solar flares occurring in sunspot groups. The data cover 1996-2014 time interval, and a total of 4262 active regions (ARs) were included in the data set. We defined the solar-flare-production potential as the ratio of the total number of flares observed in a sunspot group to the total number of the same-class sunspot groups. Our main findings are as follows: (1) large and complex sunspot groups (D+E+F) have the flare-production potential about eight times higher than the small and simple (A+B+C+H) ARs; (2) 79 per cent of all flares were produced by the large and complex sunspot groups, while only 21 per cent of flares were produced by the small groups; (3) the largest and the most complex F-class (very large and very complex) sunspot groups exhibit the highest flare-production potential (2.16 flare per sunspot group), while the smallest and the least complex A class sunspot groups show the lowest (0.05 flare per group) flare-production potential; (4) temporal variation of sunspot counts, sunspot group areas, and the total number of flares (including C flares) showed similar time profiles during both cycles with multiple peaks; (5) the mean area of ARs very well describes the flare-production potential of each group with the regression coefficient of R2 = 0.99. Most of these sunspot groups (>70 per cent) are, according to the Zurich Classification, complex ARs.

  8. Comparison of the properties of leading and trailing sunspots

    NASA Astrophysics Data System (ADS)

    Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.

    2015-01-01

    The magnetic properties of leading and trailing sunspots were compared based on SDO/HMI and SDO/AIA data with a high spatial resolution for the growth phase and maximum of cycle 24. The properties of the solar atmosphere above sunspots are also discussed independently for both of these sunspot types. It was shown that the contrast in the He II 304 ( C 304) line above the umbra of leading and single sunspots is on average smaller than such a contrast above the umbra of trailing sunspots and on average weakly depends on the umbra area for both C 304 sunspot types. It was established that the minimal angle between the field direction and the normal to the solar surface at the field measurement site is smaller in leading sunspots than in trailing ones (αmin - ls < αmin - fs ) in 84% of the considered magnetically connected "leading-trailing" sunspot pairs, and a positive correlation exists between angles αmin - ls and αmin - fs . It was found that the C 304 contrast increases with decreasing αmin - ls, fs for leading and trailing sunspots, and the C 304 - ls / C 304 - fs ratio on average decreases with increasing αmin - ls /αmin - fs ratio. The dependences of the maximal and average magnetic induction values in an umbra on the umbra area were constructed for the first time and compared independently for leading and trailing sunspots. It was concluded that the maximal and average magnetic field values do not vanish when the umbra area decreases to very small values. In all cases the magnetic field in leading and single sunspots is larger than in trailing ones.

  9. Analysis of variability of p-mode parameters in 11 years of IRIS data

    NASA Astrophysics Data System (ADS)

    Salabert, D.; Jiménez-Reyes, S. J.; Fossat, E.; Cacciani, A.; Ehgamberdiev, S.; Gelly, B.; Grec, G.; Hoeksema, J. T.; Khalikov, S.; Lazrek, M.; Pallé, P.; Schmider, F. X.; Tomczyk, S.

    2002-03-01

    11 years of IRIS (the low degree helioseismology network) have been analysed for the study of p-modes parameters variability. The duty cycle of the network data has been improved by the partial gap filling method named "repetitive music". This paper discusses the variations of all p-modes parameters along these 11 years.

  10. Reconstruction of Subdecadal Changes in Sunspot Numbers Based on the NGRIP 10Be Record

    NASA Astrophysics Data System (ADS)

    Inceoglu, F.; Knudsen, M. F.; Karoff, C.; Olsen, J.

    2014-11-01

    Sunspot observations since 1610 A.D. show that the solar magnetic activity displays long-term changes, from Maunder Minimum-like low-activity states to Modern Maximum-like high-activity episodes, as well as short-term variations, such as the pronounced 11-year periodicity. Information on changes in solar activity levels before 1610 relies on proxy records of solar activity stored in natural archives, such as 10Be in ice cores and 14C in tree rings. These cosmogenic radionuclides are produced by the interaction between Galactic cosmic rays (GCRs) and atoms in the Earth's atmosphere; their production rates are anti-correlated with the solar magnetic activity. The GCR intensity displays a distinct 11-year periodicity due to solar modulation of the GCRs in the heliosphere, which is inversely proportional to, but out of phase with, the 11-year solar cycle. This implies a time lag between the actual solar cycles and the GCR intensity, which is known as the hysteresis effect. In this study, we use the North Greenland Ice Core Project (NGRIP) records of the 10Be flux to reconstruct the solar modulation strength (Φ), which describes the modulation of GCRs throughout the heliosphere, to reconstruct both long-term and subdecadal changes in sunspot numbers (SSNs). We compare three different approaches for reconstructing subdecadal-scale changes in SSNs, including a linear approach and two approaches based on the hysteresis effect, i.e. models with ellipse-linear and ellipse relationships between Φ and SSNs. We find that the ellipse approach provides an amplitude-sensitive reconstruction and the highest cross-correlation coefficients in comparison with the ellipse-linear and linear approaches. The long-term trend in the reconstructed SSNs is computed using a physics-based model and agrees well with the other group SSN reconstructions. The new empirical approach, combining a physics-based model with ellipse-modeling of the 11-year cycle, therefore provides a method for

  11. Coupling of the Matched Gravity and Electromagnetic Fields of the Sun with Jupiter and its Moons Together in Nearest Portion of Jupiter's Orbit to the Sun as the Main Cause of the Peak of Approximately 11 Yearly Solar Cycles and Hazards from Solar Storms

    NASA Astrophysics Data System (ADS)

    Gholibeigian, Kazem; Gholibeigian, Hassan

    2016-04-01

    On March 13, 1989 the entire province of Quebec Blackout by solar storm during solar cycle 22. The solar storm of 1859, also known as the Carrington event, was a powerful geomagnetic solar storm during solar cycle 10. The solar storm of 2012 during solar cycle 24 was of similar magnitude, but it passed Earth's orbit without striking the plane. All of these solar storms occurred in the peak of 11 yearly solar cycles. In this way, the White House in its project which is focusing on hazards from solar system, in a new strategy and action plan to increase protection from damaging solar emissions, should focus on coupling of the matched Gravity and Electromagnetic Fields)GEFs) of the Sun with Jupiter and its moons together. On the other hand, in solar system, the Jupiter's gravity has largest effect to the Sun's core and its dislocation, because the gravity force between the Jupiter and the Sun is 11.834 times, In addition overlapping of the solar cycles with the Jupiter's orbit period is 11.856 years. These observable factors lead us to the effect of the Jupiter and Sun gravity fields coupling as the main cause of the approximately 11 years duration for solar cycles. Its peak in each cycle is when the Jupiter is in nearest portion to the Sun in its orbit. In this way, the other planets in their coupling with Sun help to the variations and strengthening solar cycles. [Gholibeigian, 7/24/2015http://adsabs.harvard.edu/abs/2014EGU]. In other words, the both matched GEFs are generating by the large scale forced convection system inside the stars and planets [Gholibeigian et. al, AGU Fall Meeting 2015]. These two fields are couple and strengthening each other. The Jupiter with its 67 moons generate the largest coupled and matched GEFs in its core and consequently strongest effect on the Sun's core. Generation and coupling of the Jupiter's GEFs with its moons like Europa, Io and Ganymede make this planet of thousands of times brighter and many times bigger than Earth as the

  12. An Improved Forecasting Method of Sunspot Maximum

    NASA Astrophysics Data System (ADS)

    Yin, Z.; Tian, L.; Han, Y.; Wang, B.; Han, Y.

    2015-12-01

    It has been paid more and more attention for forecasting sunspot maximum of future solar cycle in recent decades, and a variety of forecasting methods have been studied. However, to make an accurate prediction is still very difficult due to the complexities of the characteristics of solar activity. Some authors summerized a variety of methods for the maximum predictions of 22nd, 23rd, 24th solar cycles, the incomplete statistics are 63, 54 and 75 cases respectively, results of the methods, which the difference between forecasting and observed values within the range of ±15%, are 27.0%, 25.9% and 24.3% respectively. Using the 13 points smoothed value of monthly sunspot numbers, we studied correlation between sunspot number rising rate of the first 24 months of the solar cycle and the coming cycle maximum, published forecasting result that the maximum value was 139.2 ± 18.8 for 23rd solar cycle (Han et al., 2000), and the observed value is 120.8, the error is about 15.2%. The present paper describes our improved forecasting methods. First, Vondrak smoothing method is used to deal with the monthly sunspot numbers. It is studied that the relationship between the rise rate of earlier months of sunspot numbers of this smoothed sequence and the coming maximum value in each solar cycles. The results show that the first 22, 23, 24 months rise rate of sunspot numbers are highly related with the coming maximum values, and simulated prediction of maximum for 22~24 cycles show that using the 22-month rise rate of three solar cycles, the maximum forecasting error is about 13.2%, using 23-month rise rate, the maximum error is about 11.2%, while using 24-month rise rate, the maximum error is only about 9.3%. The new method not only improves the forecasting accuracy but also can make the forecasting time in advance at least half a year than the common method using 13 points monthly smoothed value.

  13. Comparing Digital Sunspot Number Counts to the New International Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Henry, Timothy

    2016-05-01

    The International Sunspot Numbers (ISN; Version 2) have been recently (2015) revised at the Sunspot Index and Long Term Solar Observations maintained at Royal Observatory of Belgium (http://www.sidc.be/silso/datafiles). ISN is a reconciled aggregate over several ground-based observatories, mostly using hand-drawn sunspot recordings. We make a detailed 10-year comparisons between the Improved Solar Observing Optical Network’s prototype digital data (2002-2011) and the ISN V1 (Version 1; pre-2015), and ISN V2. Over the ~ 10-year period, ISN V1 underestimates the sunspot number counts by up to 40% while the ISN V2 overestimates by a similar amount. We also compare the hand-drawn data from a single telescope at the National Solar Observatory with the digital data and ISN numbers. These comparisons reveal caveats that need to be taken into account, as sunspot numbers are used to forecast both the solar cycle and the near term climatology of solar cycle impacts on the space environment.

  14. Properties of sunspot umbrae of leading and trailing polarity in 1917-2013

    NASA Astrophysics Data System (ADS)

    Tlatov, Andrey Georgievich; Tlatova, K. A.; Vasil'eva, V. V.; Pevtsov, A. A.; Mursula, K.

    2015-02-01

    Using the software developed by us, we produced a digitized (tabulated) database of sunspot umbrae and pores observed at Mount Wilson Observatory (MWO) in 1917-2013. The database includes the heliographic coordinates, areas and the polarity and strength of magnetic fields of umbrae and pores in the MWO sunspot drawings. Using this database we study here the properties and long-term variation of sunspot umbrae and pores, separately for leading and trailing polarity spots. We find that the leading sunspots have tendency for larger umbrae and stronger magnetic field strength than the trailing spots. The average field strength and area of sunspot umbrae vary with sunspot cycle. Furthermore, the mean magnetic field strength in sunspot umbrae exhibits a gradual increase from early 1960s to 1990s. The nature of this increase is discussed.

  15. Semiempirical models of sunspots

    SciTech Connect

    Sobotka, M.

    1985-10-01

    On the basis of spectroscopic observations in the Mg I b1, Fe I 5434 A, and Na I D2 lines, 12 semiempirical models of sunspots of different sizes (r umbral radius, 2-8 arcsec) are constructed for several stages of their development. It is shown that the model of an umbra varies greatly with an increase in umbral radius up to a limiting value of 3.5-4 arcsec (Su = 7.5 MSH), after which the changes are small, and for a fixed umbral radius there is no significant difference between the models of sunspots in different phases of their development. 16 references.

  16. Wave phenomena in sunspots

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, Johannes

    2016-03-01

    Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 - 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along the

  17. A Standard Law for the Equatorward Drift of the Sunspot Zones

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2012-01-01

    The latitudinal location of the sunspot zones in each hemisphere is determined by calculating the centroid position of sunspot areas for each solar rotation from May 1874 to June 2012. When these centroid positions are plotted and analyzed as functions of time from each sunspot cycle maximum there appears to be systematic differences in the positions and equatorward drift rates as a function of sunspot cycle amplitude. If, instead, these centroid positions are plotted and analyzed as functions of time from each sunspot cycle minimum then most of the differences in the positions and equatorward drift rates disappear. The differences that remain disappear entirely if curve fitting is used to determine the starting times (which vary by as much as 8 months from the times of minima). The sunspot zone latitudes and equatorward drift measured relative to this starting time follow a standard path for all cycles with no dependence upon cycle strength or hemispheric dominance. Although Cycle 23 was peculiar in its length and the strength of the polar fields it produced, it too shows no significant variation from this standard. This standard law, and the lack of variation with sunspot cycle characteristics, is consistent with Dynamo Wave mechanisms but not consistent with current Flux Transport Dynamo models for the equatorward drift of the sunspot zones.

  18. Association of Plages with Sunspots: A Multi-Wavelength Study Using Kodaikanal Ca ii K and Greenwich Sunspot Area Data

    NASA Astrophysics Data System (ADS)

    Mandal, Sudip; Chatterjee, Subhamoy; Banerjee, Dipankar

    2017-02-01

    Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 Å). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of plages are also similar to those of sunspots. Different area thresholdings on the “butterfly diagram” reveal that plages of area ≥4 arcmin2 are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.

  19. Wave generation in a sunspot

    NASA Technical Reports Server (NTRS)

    Lee, Jeongwoo W.

    1993-01-01

    In this paper we analyze the generation of waves in a sunspot by extending Stein's hydrodynamic approach to the turbulent medium permeated by a strong uniform magnetic field oriented parallel to the gravity. For wave sources appropriate to the sunspot, we consider magnetic perturbations and entropy changes as well as turbulent convection. To describe the anisotropy imposed by the sunspot, we use a one-dimensional correlation function relating the turbulent eddies separated along the symmetry axis of the spot. This treatment yields several interesting possibilities for wave generation in a sunspot. First, it is demonstrated that the entropy change and magnetic perturbation can lead to a relative enhancement of acoustic wave emission. Second, the energy flux of Alfven waves may be comparable to that of acoustic waves in sunspots. Third, the anisotropy of the sunspot dynamics can lead to wave energy spectrum in a form which may explain the origin of umbral atmospheric oscillations.

  20. Investigation of the reliability of the sunspot numbers issued by Yunnan Observatory.

    NASA Astrophysics Data System (ADS)

    Li, Kejun; Zhan, Lasheng

    The sunspot numbers have been observed at Yunnan Observatory by tracing the outline sketch of sunspots with hands since 1957. The comparison of sunspot numbers issued by Yunnan Observatory and those from the Solar Geophysical Data report has been made. It is shown that the sunspot numbers of Yunnan Observatory are high-linearly correlated with those from the Solar Geophysical Data report at the whole investigated interval from Jan 1964 to Dec 1996 during the solar cycles 20, 21 and 22. The relative deviation is generally less than 10 percent.

  1. Periodic 18.6-year and cyclic 11-year induced drought and flood in northeastern China and some global implications

    NASA Astrophysics Data System (ADS)

    Currie, Robert Guinn; Fairbridge, Rhodes W.

    The general patterns of climatic evolution in China during the Holocene are reviewed, and following the postglacial eustatic rise of sea-level and the institution of the East Asian Monsoon, the systems and principal fluctuations are found to be concordant with those operating elsewhere in the globe. China's unique wealth of written history provides an abundance of proxy data on the climatic record and that record now furnishes a basis for analysing both long-term and short-term fluctuations, as well as sunspot behavior, that together provide an insight into extraterrestrial forcing. Recent Chinese work suggests a solar forcing, but our own studies suggest rather that a lunar tidal component, reinforced at times by the solar element may prove more important. Analysis of a drought-flood index for Peking (Beijing) in northeastern China since A.D. 1470 supports evidence (Hameed et al., 1983) for both periodic lunar nodal 18.6-year and solar cyclic 11-year induced drought-flood in the region. The nodal term exhibits bistable phasing with respect to epochs of tidal maxima (for our century epochs occurred at 1917.5, 1936.1, 1954.7 and 1973.3), a phenomenon previously found in drought-flood proxy data for South America (Currie, 1983), India (Currie, 1984a), North America (Currie, 1984d), and Africa (Hameed and Currie, 1985; Currie and Hameed, 1985). Solar cycle epochs of drought-flood are tabulated for the past two centuries, and compared with those from North America and Africa.

  2. Tests of Sunspot Number Sequences: 4. Discontinuities Around 1946 in Various Sunspot Number and Sunspot-Group-Number Reconstructions

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Owens, M. J.; Barnard, L.

    2016-11-01

    We use five test data series to search for, and quantify, putative discontinuities around 1946 in five different annual-mean sunspot-number or sunspot-group-number data sequences. The data series tested are the original and new versions of the Wolf/Zürich/International sunspot number composite [R_{{ISNv1}} and R_{{ISNv2}}] (respectively Clette et al. in Adv. Space Res. 40, 919, 2007 and Clette et al. in The Solar Activity Cycle 35, Springer, New York, 2015); the corrected version of R ISNv1 proposed by Lockwood, Owens, and Barnard ( J. Geophys. Res. 119, 5193, 2014a) [R C]; the new "backbone" group-number composite proposed by Svalgaard and Schatten ( Solar Phys. 291, 2016) [R_{{BB}}]; and the new group-number composite derived by Usoskin et al. ( Solar Phys. 291, 2016) [R_{{UEA}}]. The test data series used are the group-number [NG] and total sunspot area [A G] from the Royal Observatory, Greenwich/Royal Greenwich Observatory (RGO) photoheliographic data; the Ca K index from the recent re-analysis of Mount Wilson Observatory (MWO) spectroheliograms in the Calcium ii K ion line; the sunspot-group-number from the MWO sunspot drawings [N_{{MWO}}]; and the dayside ionospheric F2-region critical frequencies measured by the Slough ionosonde [foF2]. These test data all vary in close association with sunspot numbers, in some cases non-linearly. The tests are carried out using both the before-and-after fit-residual comparison method and the correlation method of Lockwood, Owens, and Barnard, applied to annual mean data for intervals iterated to minimise errors and to eliminate uncertainties associated with the precise date of the putative discontinuity. It is not assumed that the correction required is by a constant factor, nor even linear in sunspot number. It is shown that a non-linear correction is required by RC, R_{BB}, and R_{{ISNv1}}, but not by R_{{ISNv2}} or R_{{UEA}}. The five test datasets give very similar results in all cases. By multiplying the probability

  3. Local Helioseismology of Sunspots: Current Status and Perspectives

    NASA Astrophysics Data System (ADS)

    Kosovichev, Alexander G.

    2012-08-01

    Mechanisms of the formation and stability of sunspots are among the longest-standing and intriguing puzzles of solar physics and astrophysics. Sunspots are controlled by subsurface dynamics, hidden from direct observations. Recently, substantial progress in our understanding of the physics of the turbulent magnetized plasma in strong-field regions has been made by using numerical simulations and local helioseismology. Both the simulations and helioseismic measurements are extremely challenging, but it is becoming clear that the key to understanding the enigma of sunspots is a synergy between models and observations. Recent observations and radiative MHD numerical models have provided a convincing explanation for the Evershed flows in sunspot penumbrae. Also, they lead to the understanding of sunspots as self-organized magnetic structures in the turbulent plasma of the upper convection zone, which are maintained by a large-scale dynamics. Local helioseismic diagnostics of sunspots still have many uncertainties, some of which are discussed in this review. However, there have been significant achievements in resolving these uncertainties, verifying the basic results by new high-resolution observations, testing the helioseismic techniques by numerical simulations, and comparing results obtained by different methods. For instance, a recent analysis of helioseismology data from the Hinode space mission has successfully resolved several uncertainties and concerns (such as the inclined-field and phase-speed filtering effects) that might affect the inferences of the subsurface wave-speed structure of sunspots and the flow pattern. It is becoming clear that for the understanding of the phenomenon of sunspots it is important to further improve the helioseismology methods and investigate the whole life cycle of active regions, from magnetic flux emergence to dissipation. The Solar Dynamics Observatory mission has started to provide data for such investigations.

  4. 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.

  5. Sunspot prediction using neural networks

    NASA Technical Reports Server (NTRS)

    Villarreal, James; Baffes, Paul

    1990-01-01

    The earliest systematic observance of sunspot activity is known to have been discovered by the Chinese in 1382 during the Ming Dynasty (1368 to 1644) when spots on the sun were noticed by looking at the sun through thick, forest fire smoke. Not until after the 18th century did sunspot levels become more than a source of wonderment and curiosity. Since 1834 reliable sunspot data has been collected by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Naval Observatory. Recently, considerable effort has been placed upon the study of the effects of sunspots on the ecosystem and the space environment. The efforts of the Artificial Intelligence Section of the Mission Planning and Analysis Division of the Johnson Space Center involving the prediction of sunspot activity using neural network technologies are described.

  6. 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.

  7. Tests of Sunspot Number Sequences: 3. Effects of Regression Procedures on the Calibration of Historic Sunspot Data

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Owens, M. J.; Barnard, L.; Usoskin, I. G.

    2016-11-01

    We use sunspot-group observations from the Royal Greenwich Observatory (RGO) to investigate the effects of intercalibrating data from observers with different visual acuities. The tests are made by counting the number of groups [RB] above a variable cut-off threshold of observed total whole spot area (uncorrected for foreshortening) to simulate what a lower-acuity observer would have seen. The synthesised annual means of RB are then re-scaled to the full observed RGO group number [RA] using a variety of regression techniques. It is found that a very high correlation between RA and RB (r_{AB} > 0.98) does not prevent large errors in the intercalibration (for example sunspot-maximum values can be over 30 % too large even for such levels of r_{AB}). In generating the backbone sunspot number [R_{BB}], Svalgaard and Schatten ( Solar Phys., 2016) force regression fits to pass through the scatter-plot origin, which generates unreliable fits (the residuals do not form a normal distribution) and causes sunspot-cycle amplitudes to be exaggerated in the intercalibrated data. It is demonstrated that the use of Quantile-Quantile ("Q-Q") plots to test for a normal distribution is a useful indicator of erroneous and misleading regression fits. Ordinary least-squares linear fits, not forced to pass through the origin, are sometimes reliable (although the optimum method used is shown to be different when matching peak and average sunspot-group numbers). However, other fits are only reliable if non-linear regression is used. From these results it is entirely possible that the inflation of solar-cycle amplitudes in the backbone group sunspot number as one goes back in time, relative to related solar-terrestrial parameters, is entirely caused by the use of inappropriate and non-robust regression techniques to calibrate the sunspot data.

  8. Cyclic and Long-Term Variation of Sunspot Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Pevtsov, Alexei A.; Bertello, Luca; Tlatov, Andrey G.; Kilcik, Ali; Nagovitsyn, Yury A.; Cliver, Edward W.

    2014-02-01

    Measurements from the Mount Wilson Observatory (MWO) were used to study the long-term variations of sunspot field strengths from 1920 to 1958. Following a modified approach similar to that presented in Pevtsov et al. ( Astrophys. J. Lett. 742, L36, 2011), we selected the sunspot with the strongest measured field strength for each observing week and computed monthly averages of these weekly maximum field strengths. The data show the solar cycle variation of the peak field strengths with an amplitude of about 500 - 700 gauss (G), but no statistically significant long-term trends. Next, we used the sunspot observations from the Royal Greenwich Observatory (RGO) to establish a relationship between the sunspot areas and the sunspot field strengths for cycles 15 - 19. This relationship was used to create a proxy of the peak magnetic field strength based on sunspot areas from the RGO and the USAF/NOAA network for the period from 1874 to early 2012. Over this interval, the magnetic field proxy shows a clear solar cycle variation with an amplitude of 500 - 700 G and a weaker long-term trend. From 1874 to around 1920, the mean value of magnetic field proxy increases by about 300 - 350 G, and, following a broad maximum in 1920 - 1960, it decreases by about 300 G. Using the proxy for the magnetic field strength as the reference, we scaled the MWO field measurements to the measurements of the magnetic fields in Pevtsov et al. (2011) to construct a combined data set of maximum sunspot field strengths extending from 1920 to early 2012. This combined data set shows strong solar cycle variations and no significant long-term trend (the linear fit to the data yields a slope of - 0.2±0.8 G year-1). On the other hand, the peak sunspot field strengths observed at the minimum of the solar cycle show a gradual decline over the last three minima (corresponding to cycles 21 - 23) with a mean downward trend of ≈ 15 G year-1.

  9. Sunspot Time Series: Passive and Active Intervals

    NASA Astrophysics Data System (ADS)

    Zięba, S.; Nieckarz, Z.

    2014-07-01

    Solar activity slowly and irregularly decreases from the first spotless day (FSD) in the declining phase of the old sunspot cycle and systematically, but also in an irregular way, increases to the new cycle maximum after the last spotless day (LSD). The time interval between the first and the last spotless day can be called the passive interval (PI), while the time interval from the last spotless day to the first one after the new cycle maximum is the related active interval (AI). Minima of solar cycles are inside PIs, while maxima are inside AIs. In this article, we study the properties of passive and active intervals to determine the relation between them. We have found that some properties of PIs, and related AIs, differ significantly between two group of solar cycles; this has allowed us to classify Cycles 8 - 15 as passive cycles, and Cycles 17 - 23 as active ones. We conclude that the solar activity in the PI declining phase (a descending phase of the previous cycle) determines the strength of the approaching maximum in the case of active cycles, while the activity of the PI rising phase (a phase of the ongoing cycle early growth) determines the strength of passive cycles. This can have implications for solar dynamo models. Our approach indicates the important role of solar activity during the declining and the rising phases of the solar-cycle minimum.

  10. Forecasting the Time Series of Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Aguirre, L. A.; Letellier, C.; Maquet, J.

    2008-05-01

    Forecasting the solar cycle is of great importance for weather prediction and environmental monitoring, and also constitutes a difficult scientific benchmark in nonlinear dynamical modeling. This paper describes the identification of a model and its use in the forecasting the time series comprised of Wolf’s sunspot numbers. A key feature of this procedure is that the original time series is first transformed into a symmetrical space where the dynamics of the solar dynamo are unfolded in a better way, thus improving the model. The nonlinear model obtained is parsimonious and has both deterministic and stochastic parts. Monte Carlo simulation of the whole model produces very consistent results with the deterministic part of the model but allows for the determination of confidence bands. The obtained model was used to predict cycles 24 and 25, although the forecast of the latter is seen as a crude approximation, given the long prediction horizon required. As for the 24th cycle, two estimates were obtained with peaks of 65±16 and of 87±13 units of sunspot numbers. The simulated results suggest that the 24th cycle will be shorter and less active than the preceding one.

  11. Distribution of sunspot umbral areas - 1917-1982

    SciTech Connect

    Bogdan, T.J.; Gilman, P.A.; Lerche, I.; Howard, R.

    1988-04-01

    Over 24,000 measurements of individual sunspot umbral areas taken from the Mount Wilson white-light plate collection covering the period 1917-1982 are used to determine the relative size distribution of sunspot umbras. In the range 1.5-141 millionths of a solar hemisphere, the sunspot umbral areas are found to be distributed lognormally. Moreover, the same distribution is obtained for all phases of the solar cycle (maximum, minimum, ascending, descending), as well as for various individual cycles, between 1917 and 1982. Both the mean and the geometric logarithmic standard deviation of this distribution appear to be intrinsically constant over the entire data set; only the number of spots exhibits the familiar solar cycle variations. If the observed lognormal umbral size distribution is not a particular attribute of the sunspot umbras but is instead of a more fundamental property of emerging magnetic flux, then the data would predict a maximum in the size spectrum of photospheric magnetic structures for flux tubes with radii in the range 500-800 km. The absence of solar cycle variations in the relative distribution of umbral areas and especially the lognormal character of this distribution may both argue for the fragmentation of magnetic elements in the solar envelope. 22 references.

  12. Tests of Sunspot Number Sequences: 1. Using Ionosonde Data

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Scott, C. J.; Owens, M. J.; Barnard, L.; Willis, D. M.

    2016-11-01

    More than 70 years ago, it was recognised that ionospheric F2-layer critical frequencies [foF2] had a strong relationship to sunspot number. Using historic datasets from the Slough and Washington ionosondes, we evaluate the best statistical fits of foF2 to sunspot numbers (at each Universal Time [UT] separately) in order to search for drifts and abrupt changes in the fit residuals over Solar Cycles 17 - 21. This test is carried out for the original composite of the Wolf/Zürich/International sunspot number [R], the new "backbone" group sunspot number [R_{BB}], and the proposed "corrected sunspot number" [RC]. Polynomial fits are made both with and without allowance for the white-light facular area, which has been reported as being associated with cycle-to-cycle changes in the sunspot-number-foF2 relationship. Over the interval studied here, R, R_{BB}, and RC largely differ in their allowance for the "Waldmeier discontinuity" around 1945 (the correction factor for which for R, R_{BB}, and RC is, respectively, zero, effectively over 20 %, and explicitly 11.6 %). It is shown that for Solar Cycles 18 - 21, all three sunspot data sequences perform well, but that the fit residuals are lowest and most uniform for R_{BB}. We here use foF2 for those UTs for which R, R_{BB}, and RC all give correlations exceeding 0.99 for intervals both before and after the Waldmeier discontinuity. The error introduced by the Waldmeier discontinuity causes R to underestimate the fitted values based on the foF2 data for 1932 - 1945, but R_{BB} overestimates them by almost the same factor, implying that the correction for the Waldmeier discontinuity inherent in R_{BB} is too large by a factor of two. Fit residuals are smallest and most uniform for RC, and the ionospheric data support the optimum discontinuity multiplicative correction factor derived from the independent Royal Greenwich Observatory (RGO) sunspot group data for the same interval.

  13. The new Sunspot and Group Numbers: a full recalibration

    NASA Astrophysics Data System (ADS)

    Clette, Frédéric; Svalgaard, Leif; Cliver, Edward W.; Vaquero, José M.; Lefèvre, Laure

    2015-08-01

    After a 4-year research effort, we present here the first end-to-end revision of the Sunspot Number since the creation of this reference index of solar activity by Rudolf Wolf in 1849 and the simultaneous re-calibration of the Group Number, which leads to the elimination of the past incompatibility between those two independent data sets.Most corrections relied entirely on original sunspot data, using various approaches. Newly recovered historical sunspot records were added and a critical data selection was applied for the 17th and 18th century, confirming the low solar activity during the Maunder Minimum. Over the 19th century, the k scaling coefficients of individual observers were recomputed using new statistical methodologies, like the "backbone" method resting on a chain of long-duration observers. After identifying major changes in the observing methods, two major inhomogeneities were corrected in 1884 in the Group Number (~40% upward drift) and in 1947 in the Sunspot Number (~20% overestimate). Finally, a full re-computation of the group and sunspot numbers was done over the last 50 years, using all original data from the 270 stations archived by the World Data Center - SILSO in Brussels.The new Sunspot Number series definitely exclude a progressive rise in average solar activity between the Maunder Minimum and an exceptional Grand Maximum in the late 20th century. Residual differences between the Group and Sunspot Numbers over the past 250 years confirm that they reflect different properties of the solar cycle and that the average number of spots per group varies over time, as it just happened in the recent unexpected evolution of cycles 23 and 24. We conclude on the implications for solar cycle and Earth climate studies and on important new conventions adopted for the new series: new unit scales (constant "heritage" factors 0.6 and 12.08 dropped for the Sunspot and Group Numbers respectively), new SN and GN symbols and a new version-tracking scheme

  14. Temporal Variation of Different Categories Sunspot Groups since 1996: Their Relation with Geomagnetic Ap and Dst Indices

    NASA Astrophysics Data System (ADS)

    Kilcik, Ali; Ozguc, Atila; Rozelot, Jean Pierre; Donmez, Burcin; Yurchyshyn, Vasyl

    2016-07-01

    We studied the temporal variation of the number of sunspot groups and sunspot counts in these groups in four categories as small (A, B), medium (C), large (D, E, F) and final (H modified Zurich classes) since 1996. Then we compared these data sets with geomagnetic Ap and Dst indices. In results of our analysis we found followings: 1) different categories sunspot groups and sunspot counts in these groups behave differently during a solar cycle. ii) Response of geomagnetic indices to these data sets are also different.

  15. Rotation rates of leader and follower sunspots

    SciTech Connect

    Gilman, P.A.; Howard, R.

    1985-08-01

    We have measured the rotation rates of leader and follower sunspots found on Mount Wilson white light plates, for the years 1917--1983. We find that at all latitudes, leader spots rotate faster than follower spots by approx.0/sup 0/.1 per day, or 14 m s/sup -1/. We also find that, when examined separately, leaders and followers show the same variations in rotation with cycle phase as do all spots taken together, as reported earlier in Gilman and Howard. Leaders and followers show similar variations in rotation rate even on an annual basis. Thus, while leaders and followers in each group diverge in longitude from each other at an average rate of approx.0/sup 0/.1 per day, each is separately speeding up or slowing down its rotation according to the phase in the cycle, and by a similar amount. Leaders and followers also give about the same covariance of longitude and latitude motions, indicating that whole sunspot groups participate in tracing the apparent angular momentum transport toward the equator, as previously reported for all spots in Gilman and Howard.

  16. Solar activity prediction of sunspot numbers (verification). Predicted solar radio flux; predicted geomagnetic indices Ap and Kp. [space shuttle program: satellite orbital lifetime

    NASA Technical Reports Server (NTRS)

    Newman, S. R.

    1980-01-01

    Efforts to further verify a previously reported technique for predicting monthly sunspot numbers over a period of years (1979 to 1989) involved the application of the technique over the period for the maximum epoch of solar cycle 19. Results obtained are presented. Methods and results for predicting solar flux (F10.7 cm) based on flux/sunspot number models, ascent and descent, and geomagnetic activity indices as a function of sunspot number and solar cycle phase classes are included.

  17. The Effect of Sunspot Weighting

    NASA Astrophysics Data System (ADS)

    Svalgaard, Leif; Cagnotti, Marco; Cortesi, Sergio

    2017-02-01

    Although W. Brunner began to weight sunspot counts (from 1926), using a method whereby larger spots were counted more than once, he compensated for the weighting by not counting enough smaller spots in order to maintain the same reduction factor (0.6) as was used by his predecessor A. Wolfer to reduce the count to R. Wolf's original scale, so that the weighting did not have any effect on the scale of the sunspot number. In 1947, M. Waldmeier formalized the weighting (on a scale from 1 to 5) of the sunspot count made at Zurich and its auxiliary station Locarno. This explicit counting method, when followed, inflates the relative sunspot number over that which corresponds to the scale set by Wolfer (and matched by Brunner). Recounting some 60,000 sunspots on drawings from the reference station Locarno shows that the number of sunspots reported was "over counted" by {≈} 44 % on average, leading to an inflation (measured by an effective weight factor) in excess of 1.2 for high solar activity. In a double-blind parallel counting by the Locarno observer M. Cagnotti, we determined that Svalgaard's count closely matches that of Cagnotti, allowing us to determine from direct observation the daily weight factor for spots since 2003 (and sporadically before). The effective total inflation turns out to have two sources: a major one (15 - 18 %) caused by weighting of spots, and a minor source (4 - 5 %) caused by the introduction of the Zürich classification of sunspot groups which increases the group count by 7 - 8 % and the relative sunspot number by about half that. We find that a simple empirical equation (depending on the activity level) fits the observed factors well, and use that fit to estimate the weighting inflation factor for each month back to the introduction of effective inflation in 1947 and thus to be able to correct for the over-counts and to reduce sunspot counting to the Wolfer method in use from 1894 onwards.

  18. Modulation Cycles of Galactic Cosmic Ray Diurnal Anisotropy Variation

    NASA Astrophysics Data System (ADS)

    Oh, S. Y.; Yi, Y.; Bieber, J. W.

    2010-03-01

    The diurnal variation of the galactic cosmic ray (GCR) count rates measured by a ground-based neutron monitor (NM) station represents an anisotropic flow of GCR at 1 AU. The variation of the local time of GCR maximum intensity (we call the phase) is thought in general to have a period of two sunspot cycles (22 years). However, other interpretations are also possible. In order to determine the cyclic behavior of GCR anisotropic variation more precisely, we have carried out a statistical study on the diurnal variation of the phase. We examined 54-year data of Huancayo (Haleakala), 40-year data from Rome, and 43-year data from Oulu NM stations using the ‘pile-up’ method and the F-test. We found that the phase variation has two components: of 22-year and 11-year cycles. All NM stations show mainly the 22-year phase variation controlled by the drift effect due to solar polar magnetic field reversal, regardless of their latitudinal location (cut-off rigidity). However, the lower the NM station latitude is (the higher the cut-off rigidity is), the higher is the contribution from the 11-year phase variation controlled by the diffusion effect due to the change in strength of the interplanetary magnetic fields associated with the sunspot cycle.

  19. AAVSO Visual Sunspot Observations vs. SDO HMI Sunspot Catalog

    NASA Astrophysics Data System (ADS)

    Howe, R.

    2014-06-01

    (Abstract only) The most important issue with regard to using the SDO HMI data from the National Solar Observatory (NSO, http://www.nso.edu/staff/fwatson/STARA) is that their current model for creating sunspot counts does not split in groups and consequently does not provide a corresponding group count and Wolf number. As it is a different quantity, it cannot be mixed with the data from our sunspot networks. For the AAVSO with about seventy stations contributing each day, adding HMI sunspot data would anyway hardly change the resulting index. Perhaps, the best use of HMI data is for an external validation, by exploiting the fact that HMI provides a series that is rather close to the sunspot number and is acquired completely independently. So, it is unlikely to suffer from the same problems (jumps, biases) at the same time. This validation only works for rather short durations, as the lifetime of space instruments is limited and aging effects are often affecting the data over the mission. In addition, successive instruments have different properties: for example, the NSO model has not managed yet to reconcile the series from MDI and HMI. There is a ~10-15% jump. The first challenge that should be addressed by AAVSO using HMI data is the splitting in groups and deriving group properties. Then, together with the sunspot counts and areas per group, a lot more analyses and diagnostics can be derived (like the selective disappearance of the smallest sunspots?), that can help interpreting trends in the ratio SSN/other solar indices and many other solar effects.

  20. In-depth survey of sunspot and active region catalogs

    NASA Astrophysics Data System (ADS)

    Lefèvre, Laure; Clette, Frédéric; Baranyi, Tunde

    2011-08-01

    When consulting detailed photospheric catalogs for solar activity studies spanning long time intervals, solar physicists face multiple limitations in the existing catalogs: finite or fragmented time coverage, limited time overlap between catalogs and even more importantly, a mismatch in contents and conventions. In view of a study of new sunspot-based activity indices, we have conducted a comprehensive survey of existing catalogs. In a first approach, we illustrate how the information from parallel catalogs can be merged to form a much more comprehensive record of sunspot groups. For this, we use the unique Debrecen Photoheliographic Data (DPD), which is already a composite of several ground observatories and SOHO data, and the USAF/Mount Wilson catalog from the Solar Optical Observing Network (SOON). We also describe our semi-interactive cross-identification method, which was needed to match the non-overlapping solar active region nomenclature, the most critical and subtle step when working with multiple catalogs. This effort, focused here first on the last two solar cycles, should lead to a better central database collecting all available sunspot group parameters to address future solar cycle studies beyond the traditional sunspot index time series Ri.

  1. The Revised Brussels-Locarno Sunspot Number (1981 - 2015)

    NASA Astrophysics Data System (ADS)

    Clette, Frédéric; Lefèvre, Laure; Cagnotti, Marco; Cortesi, Sergio; Bulling, Andreas

    2016-11-01

    In 1981, the production of the international sunspot number moved from the Zürich Observatory to the Royal Observatory of Belgium, with a new pilot station: the Specola Solare Ticinese Observatory in Locarno, Switzerland. This marked a profound transition in the history of the sunspot number. Those recent decades are particularly important as they provide the link between recent modern solar indices and the entire sunspot-number series extending back to the eighteenth century. However, large variations have recently been identified in the scale of the sunspot number during this recent time period. Here, we refine the determination of those recent inhomogeneities by reconstructing a new average sunspot-number series [SN] from a subset of long-duration stations between 1981 and 2015. We also extend this reconstruction by gathering long time series from 35 stations over 1945 - 2015, thus straddling the critical 1981 transition. In both reconstructions, we also derive a parallel group number series [GN] built by the same method from exactly the same data set. Our results confirm the variable trends associated with drifts of the Locarno pilot station, which start only in 1983. They lead to a fully uniform SN-series over the entire 1945 - 2015 interval. By comparing the new SN- and GN-series, we find that a constant quadratic relation exists between those two indices over Cycles 19 to 23. Comparisons with a few other solar indices additionally validate this and reveal some possible undetected problems in those series. Using this new reference SN, we find that observing stations are surprisingly grouped among distinct subsets that share similar personal k-scaling coefficients. These various results also open the way to implementing a more advanced method for producing the sunspot number in the future.

  2. SOHO reveals how sunspots take a stranglehold on the Sun

    NASA Astrophysics Data System (ADS)

    2001-11-01

    Bernhard Fleck, ESA's project scientist for SOHO, comments, "The origin and stability of sunspots has been one of the long-standing mysteries in solar physics. I am delighted to see that with SOHO we are beginning to crack this problem." The gas flows around and beneath a sunspot have been detected by a team of scientists in the USA, using the Michelsen Doppler Imager (MDI) on SOHO. The instrument explores the solar interior by detecting natural sound waves at a million points on the Sun's surface. "After many years of contradictory theories about sunspots, MDI on SOHO is at last telling us what really happens," comments Junwei Zhao of Stanford University, California, lead author of a report published in the Astrophysical Journal. Inflows and downflows similar to those now detected with SOHO were envisaged in 1974 by Friedrich Meyer of Germany's Max-Planck- Institut für Physik und Astrophysik, and his colleagues. A similar expectation figured in a theory of sunspots advanced in 1979 by Eugene Parker of Chicago. "Our observation seems to provide strong evidence for both predictions," Zhao says. Sunspots have fascinated scientists since Galileo's time, 400 years ago, when they shattered a belief that the Sun was divinely free of any blemish. As symptoms of intense magnetic activity, sunspots are often associated with solar flares and mass ejections that affect space weather and the Earth itself. The Sun's activity peaks roughly every 11 years, and the latest maximum in the sunspot count occurred in 2000. Even with huge advances in helioseismology, which deduces layers and flows inside the Sun by analysis of sound waves that travel through it and agitate the surface, seeing behind the scenes in sunspots was never going to be easy. The MDI team refined a method of measuring the travel time of sound waves, invented in 1993 by Thomas Duvall of NASA Goddard, called solar tomography. It is like deducing what obstacles cross-country runners have faced, just by seeing in

  3. Analyses of relationship between Loess Plateau erosion and sunspots based on wavelet transform

    NASA Astrophysics Data System (ADS)

    Gao, P.; Mu, X.-M.; Li, R.; Wang, F.

    2011-01-01

    Loess Plateau is one of the worst soil erosion regions in the world, which may resulted from various factors such as precipitation, land cover and land use, soil, vegetation, human intervention, as well as solar activities. The purpose of this study is to find the relationship between soil erosion and sunspot activity on the Loess Plateau, through analyses of the sunspot relative number and the long-term sediment discharge series in Longmen station in the Yellow River based on the Morlet wavelet method. In this paper, annual sediment discharge series from 1919-2008 in Longmen station and the sunspot relative number were decomposed with Complex Morlet wavelet. The results of real part, modulus and the second power of modulus showed an obvious periodic variability in sediment discharge, with 25-40 years, about 10 years, and less than 10 years scales. There are six centers of energy. From the wavelet variance, 6, 12, and 35 years periods were detected within 50-year scale, and the 35-year period is the most significant one. Similar analyses were conducted for the sunspot relative number during the same period of 1919-2008. The sunspot series showed an 11-year periodic variation, and two energy center. Then, the correlation analyses for 11-year scale were computed. From a long-term period (1919-2008) view, there is no significant correlation between the sediment discharge and the sunspot relative number; however, it is evident that the correlations exist in short-term periods. The results also indicate that the relationships between solar activities and the erosion of the Loess Plateau are complicated.

  4. RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS

    SciTech Connect

    McClintock, B. H.; Norton, A. A.; Li, J. E-mail: aanorton@stanford.edu

    2014-12-20

    Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.

  5. Imaging sunspots using helioseismic methods.

    PubMed

    Tong, C H

    2005-12-15

    The origin of sunspots is one of the most fundamental and yet poorly understood areas in solar physics. Imaging local anomalous features in the solar interior offers a direct way to unravel the underlying physical processes of sunspots and the mechanisms behind their formation. The advent of local helioseismology in the last few years has, for the first time, made it possible to image local internal solar structures. High-resolution satellite and ground telescope data which reveal the details of the vibrations of the visible solar surface are essential in the development of local helioseismology. We are now in a position to transfer the seismic methods that have traditionally been used to study the Earth's interior to solar investigations. This interdisciplinary approach to developing seismic imaging techniques is opening up new ways of understanding the flow and other structural characteristics beneath sunspots. In this article, I review recent progress in the imaging of sunspots and the surrounding solar active regions. By highlighting the strengths of seismic methods and the challenges facing local helioseismology, I discuss some of the new research directions and possibilities that have arisen from this novel type of seismic imaging.

  6. The area and absolute magnetic flux of sunspots over the past 400 years

    NASA Astrophysics Data System (ADS)

    Nagovitsyn, Yu. A.; Tlatov, A. G.; Nagovitsyna, E. Yu.

    2016-09-01

    A new series of yearly-mean relative sunspot numbers SN 2 that has been extrapolated into the past (to 1610) is presented. The Kislovodsk series with the scale factor b = 1.0094 ± 0.0059 represents a reasonable continuation of the mean-monthly and mean-yearly total sunspot areas of the Greenwich series after 1976. The second maximum of the 24th solar-activity cycle was not anomalously low, and was no lower than 6 of the past 13 cycles. A series A 2 of values for the total sunspot area in 1610-2015 has been constructed, and is complementary to new versions of the series of the relative number of sunspots SN 2 and the number of sunspot groups GN 2. When needed, this series can be reduced to yield a quantity having a clear physical meaning—the spot absolute magnetic flux Φ Σ( t)[Mx] = 2.16 × 1019 A( t) [mvh]. The maximum sunspot area during the Maunder minimum is much higher in the new series compared to the previous version. This at least partially supports the validity of arguments that cast doubt on the anomalously low ampltude of the solar cycles during the Maunder minimum that has been assumed by many researchers earlier.

  7. Trisomy 13 (Patau syndrome) with an 11-year survival.

    PubMed

    Zoll, B; Wolf, J; Lensing-Hebben, D; Pruggmayer, M; Thorpe, B

    1993-01-01

    Trisomy 13 is very rare in live-born children. Only a small number of these children survive the first year and very few cases are reported to live longer. Survival time depends partly on the cytogenetic findings--full trisomy 13 or trisomy 13 mosaicism--and partly on the existence of serious somatic malformations. We report on a 11-year-old girl with full trisomy 13. In this case, missing cerebral and cardiovascular malformations probably allowed the long survival.

  8. A multi-instrument analysis of sunspot umbrae

    SciTech Connect

    Watson, F. T.; Penn, M. J.; Livingston, W.

    2014-05-20

    The recent solar minimum and rise phase of solar cycle 24 have been unlike any period since the early 1900s. This article examines some of the properties of sunspot umbrae over the last 17 yr with three different instruments on the ground and in space: MDI, HMI and BABO. The distribution of magnetic fields and their evolution over time is shown and reveals that the field distribution in cycle 24 is fundamentally different from that in cycle 23. The annual average umbral magnetic field is then examined for the 17 yr observation period and shows a small decrease of 375 G in sunspot magnetic fields over the period 1996-2013, but the mean intensity of sunspot umbrae does not vary significantly over this time. A possible issue with sample sizes in a previous study is then explored to explain disagreements in data from two of the source instruments. All three instruments show that the relationship between umbral magnetic fields and umbral intensity agrees with past studies in that the umbral intensity decreases as the field strength increases. This apparent contradiction can be explained by the range of magnetic field values measured for a given umbral intensity being larger than the measured 375 G change in umbral field strength over time.

  9. On the Relation Between Sunspot Area and Sunspot Number

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    Often, the relation between monthly or yearly averages of total sunspot area, A, and sunspot number, R, has been described using the formula A = 16.7 R. Such a simple relation, however, is erroneous. The yearly ratio of A/R has varied between 5.3 in 1964 to 19.7 in 1926, having a mean of 13.1 with a standard deviation of 3.5. For 1875-1976 (corresponding to the Royal Greenwich Observatory timeframe), the yearly ratio of A/R has a mean of 14.1 with a standard deviation of 3.2, and it is found to differ significantly from the mean for 1977-2004 (corresponding to the United States Air Force/National Oceanic and Atmospheric Administration Solar Optical Observing Network timeframe), which equals 9.8 with a standard deviation of 2.1. Scatterplots of yearly values of A versus R are highly correlated for both timeframes and they suggest that a value of R = 100 implies A=1,538 +/- 174 during the first timeframe, but only A=1,076 +/- 123 for the second timeframe. Comparison of the yearly ratios adjusted for same day coverage against yearly ratios using Rome Observatory measures for the interval 1958-1998 indicates that sunspot areas during the second timeframe are inherently too low.

  10. The Solar Radio Microwave Flux and the Sunspot Number

    NASA Astrophysics Data System (ADS)

    Svalgaard, L.; Hudson, H. S.

    2009-12-01

    Since 1947 the flux of microwaves from the Sun at wavelengths between 3 and 30 cm [frequencies between 10 and 1 GHz] has been routinely measured. This emission comes from both thromosphere and the corona and has two main sources: thermal bremsstrahlung (free-free emission) and thermal gyroradiation. These mechanisms give rise to enhanced radiation when the density and magnetic field increase, so the microwave radiation is a good measure of general solar activity. Strong magnetic fields occur in the network and can persist for weeks or longer; hence there is a strong rotational signal in the emission superposed on a solar cycle variation of the background coronal signal. The radio flux measurements can be calibrated absolutely and are not very sensitive to observing conditions, and in principle have no personal equation. They may thus be the most objective measure of solar activity, and our many decades-long flux record could throw light on the important issue of the long-term variation of solar activity. The longest series of observations F10.7, begun by Covington in Ottawa, Canada in April 1947 and maintained to this day. Other observatories also have long and continuing series of measurements of the microwave flux. One can now ask how this measure of solar activity compares to other measures, in particular the sunspot number. We correlate the sunspot number against the F10.7 flux for the interval 1951-1988, and obtain a good polynomial fit (R^2 = 0.977) up until ~1989.0 after which time the observed sunspot number falls progressively below the fitted number. Three obvious hypotheses present themselves: 1) The sunspot counting procedure or observers have changed, with resulting artificial changes of the sunspot number as they have in the past. 2) Physical changes in the corona or chromosphere have occurred. 3) Livingston & Penn’s observations that the sunspots are getting warmer during the last decade, leading to a decreased contrast with the surrounding

  11. Technique for automatic detection of sunspots from full-disk continuum images.

    NASA Astrophysics Data System (ADS)

    Goel, Suruchi; Mathew, Shibu

    2012-07-01

    Sunspot identification and characterization including location, area, lifetime, brightness, and so forth are required for a quantitative study of the solar cycle. Sunspot studies are also important for the modeling of the total solar irradiance during the solar cycle. We have developed the procedure for automatic detection of sunspots from full-disk continuum intensity images obtained from SOHO/MDI and it is also applicable for high resolution images from SDO/HMI. In white-light images sunspots are considerably darker than the surrounding photosphere because they are cooler than the average temperature of the solar surface (about 6000 K). Our procedure is based on active contour method using level set formulation. The basic idea of level set formulation for binary image segmentation is to define a 2-D level set function such as it has opposite signs for two regions and the boundary is defined as 'zero' of level-set function. We implemented the SBGFRLS (Selective Binary and Gaussian Filtering Regularized Level Set) method for sunspot detection. It first selectively penalizes the level set function to be binary, and then uses a Gaussian smoothing kernel to regularize it. This method is computationally simple and fast. The algorithm was run in two levels, once for umbra and then for penumbra detection with different parameters settings. Then, using umbra-penumbra position information, sunspots can be identified. The proposed procedure can give all parameters of sunspots like, location; center of gravity; area, mean (/min/max) intensity of umbra/penumbra etc., which can be compared with the other available sunspots catalog.

  12. The effects of sunspots on solar irradiance

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.; Silva, S.; Woodard, M.; Willson, R. C.

    1982-01-01

    It is pointed out that the darkness of a sunspot on the visible hemisphere of the sun will reduce the solar irradiance on the earth. Approaches are discussed for obtaining a crude estimate of the irradiance deficit produced by sunspots and of the total luminosity reduction for the whole global population of sunspots. Attention is given to a photometric sunspot index, a global measure of spot flux deficit, and models for the compensating flux excess. A model is shown for extrapolating visible-hemisphere spot areas to the invisible hemisphere. As an illustration, this extrapolation is used to calculate a very simple model for the reradiation necessary to balance the flux deficit.

  13. Oscillations in a sunspot with light bridges

    SciTech Connect

    Yuan, Ding; Su, Jiangtao; Yan, Yihua; Tan, Baolin; Nakariakov, Valery M.; Huang, Zhenghua; Li, Bo

    2014-09-01

    The Solar Optical Telescope on board Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 2013 August 31. We analyzed a two-hour Ca II H emission intensity data set and detected strong five-minute oscillation power on both LBs and in the inner penumbra. The time-distance plot reveals that the five-minute oscillation phase does not vary significantly along the thin bridge, indicating that the oscillations are likely to originate from underneath it. The slit taken along the central axis of the wide LB exhibits a standing wave feature. However, at the center of the wide bridge, the five-minute oscillation power is found to be stronger than at its sides. Moreover, the time-distance plot across the wide bridge exhibits a herringbone pattern that indicates a counter-stream of two running waves, which originated at the bridge's sides. Thus, the five-minute oscillations on the wide bridge also resemble the properties of running penumbral waves. The five-minute oscillations are suppressed in the umbra, while the three-minute oscillations occupy all three cores of the sunspot's umbra, separated by the LBs. The three-minute oscillations were found to be in phase at both sides of the LBs. This may indicate that either LBs do not affect umbral oscillations, or that umbral oscillations at different umbral cores share the same source. It also indicates that LBs are rather shallow objects situated in the upper part of the umbra. We found that umbral flashes (UFs) follow the life cycles of umbral oscillations with much larger amplitudes. They cannot propagate across LBs. UFs dominate the three-minute oscillation power within each core; however, they do not disrupt the phase of umbral oscillation.

  14. Long-term variations in the sunspot magnetic fields and bipole properties from 1918 to 2014

    NASA Astrophysics Data System (ADS)

    Tlatova, K. A.; Vasil'eva, V. V.; Pevtsov, A. A.

    2015-12-01

    Long-term measurements of sunspot magnetic fields have been analyzed with the use of the Mount Wilson Observatory (MWO) data based on the digitization of the magnetic field strength ( B) and umbra and pore areas from 1918 to 2014. Time variations in the magnetic field strength and the possible causes of such variations (which are related to variations in the solar activity level and instrumental effects) were considered. It was shown that artifacts related to instrumental effects exist in the measurements for small sunspots and pores. The magnetic bipole characteristics were determined for the sunspot groups. It was established that the tilt angle of the magnetic bipole axis of even cycles is larger than the tilt angle in the next odd cycles (except for the cycle pair 22-23).

  15. LONG-TERM MEASUREMENTS OF SUNSPOT MAGNETIC TILT ANGLES

    SciTech Connect

    Li Jing; Ulrich, Roger K.

    2012-10-20

    Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and SOHO/MDI magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median tilts increase with increasing latitude (Joy's law) at a rate of {approx}0.{sup 0}5 per degree of latitude. Tilt angles of spots appear largely invariant with respect to time at a given latitude, but they decrease by {approx}0.{sup 0}9 per year on average, a trend that largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean tilt angles. On average, the tilts are greater in the Southern than in the Northern Hemisphere for all latitude zones, and the differences increase with increasing latitude.

  16. 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.

  17. 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

  18. Acquired myopia in 11-year-old children.

    PubMed

    Peckham, C S; Gardiner, P A; Goldstein, H

    1977-02-26

    Children who had acquired myopia by the age of 11 years were identified from a nationally representative sample. There were no overall sex differences in its occurrence but myopia was more common in children from non-manual families than in those from manual families. Short-sighted children were more likely to come from small families and to be of higher birth order than children with normal vision, and these associations held within each social class. At 11 years myopic children showed striking advantages in educational performance over their normal-sighted peers, as judged by tests of reading, arithmetic, and general ability. After adjustments had been made for social background, this age gain still amounted to over one year. Findings obtained at 7 years of age showed that superior educational attainments were already apparent before the onset of myopia. Children with myopia read in their leisure time more often than normally sighted children, but despite the visual impairment, they participated in outdoor sports as often as other children.

  19. Wings of the butterfly: Sunspot groups for 1826-2015

    NASA Astrophysics Data System (ADS)

    Leussu, R.; Usoskin, I. G.; Senthamizh Pavai, V.; Diercke, A.; Arlt, R.; Denker, C.; Mursula, K.

    2017-03-01

    The spatio-temporal evolution of sunspot activity, the so-called Maunder butterfly diagram, has been continously available since 1874 using data from the Royal Greenwich Observatory, extended by SOON network data after 1976. Here we present a new extended butterfly diagram of sunspot group occurrence since 1826, using the recently digitized data from Schwabe (1826-1867) and Spörer (1866-1880). The wings of the diagram are separated using a recently developed method based on an analysis of long gaps in sunspot group occurrence in different latitude bands. We define characteristic latitudes, corresponding to the start, end, and the largest extent of the wings (the F, L, and H latitudes). The H latitudes (30°-45°) are highly significantly correlated with the strength of the wings (quantified by the total sum of the monthly numbers of sunspot groups). The F latitudes (20°-30°) depict a weak tendency, especially in the southern hemisphere, to follow the wing strength. The L latitudes (2°-10°) show no clear relation to the wing strength. Overall, stronger cycle wings tend to start at higher latitudes and have a greater wing extent. A strong (5-6)-cycle periodic oscillation is found in the start and end times of the wings and in the overlap and gaps between successive wings of one hemisphere. While the average wing overlap is zero in the southern hemisphere, it is two to three months in the north. A marginally significant oscillation of about ten solar cycles is found in the asymmetry of the L latitudes. The new long database of butterfly wings provides new observational constraints to solar dynamo models that discuss the spatio-temporal distribution of sunspot occurrence over the solar cycle and longer. Digital data for Fig. 1 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A131

  20. Single spots, unipolar magnetic regions, and pairs of spots: 2. The development of sunspot pairs and the Hale boundary

    NASA Astrophysics Data System (ADS)

    Akasofu, Syun-Ichi

    2015-04-01

    Sunspot pairs develop in connection with cell networks at or near the boundaries of positive and negative unipolar magnetic (UM) field regions. In this paper, we confirm his findings by recent data. In this connection, Svalgaard and Wilcox (1976) found also that solar activities occur only at one side of UM boundaries, called the "Hale boundary," on the basis of their observation of the interplanetary magnetic field. It is shown in this paper that the Hale boundary can be recognized also on the photosphere. Further, it is shown that new UM regions grow at the beginning of a new sunspot cycle, and active regions and sunspot pairs tend to develop at or near newly developing Hale boundaries. Thus, it is suggested that UM regions and specifically Hale boundaries are very important for the formation of active regions, sunspots, and sunspot pairs. These facts suggest also that UM regions are not merely remnants of decaying old spots and active regions. Some of the essential features of sunspot pairs, as well as their relationship to the Hale boundary in both even and odd cycles are presented in one figure, illustrating several requirements for a theory of the formation of single spots and sunspot pairs.

  1. CORONAL MASS EJECTIONS AND THE SOLAR CYCLE VARIATION OF THE SUN’S OPEN FLUX

    SciTech Connect

    Wang, Y.-M.; Sheeley, N. R. Jr. E-mail: neil.sheeley@nrl.navy.mil

    2015-08-20

    The strength of the radial component of the interplanetary magnetic field (IMF), which is a measure of the Sun’s total open flux, is observed to vary by roughly a factor of two over the 11 year solar cycle. Several recent studies have proposed that the Sun’s open flux consists of a constant or “floor” component that dominates at sunspot minimum, and a time-varying component due to coronal mass ejections (CMEs). Here, we point out that CMEs cannot account for the large peaks in the IMF strength which occurred in 2003 and late 2014, and which coincided with peaks in the Sun’s equatorial dipole moment. We also show that near-Earth interplanetary CMEs, as identified in the catalog of Richardson and Cane, contribute at most ∼30% of the average radial IMF strength even during sunspot maximum. We conclude that the long-term variation of the radial IMF strength is determined mainly by the Sun’s total dipole moment, with the quadrupole moment and CMEs providing an additional boost near sunspot maximum. Most of the open flux is rooted in coronal holes, whose solar cycle evolution in turn reflects that of the Sun’s lowest-order multipoles.

  2. Sunspots and ENSO relationship using Markov method

    NASA Astrophysics Data System (ADS)

    Hassan, Danish; Iqbal, Asif; Ahmad Hassan, Syed; Abbas, Shaheen; Ansari, Muhammad Rashid Kamal

    2016-01-01

    The various techniques have been used to confer the existence of significant relations between the number of Sunspots and different terrestrial climate parameters such as rainfall, temperature, dewdrops, aerosol and ENSO etc. Improved understanding and modelling of Sunspots variations can explore the information about the related variables. This study uses a Markov chain method to find the relations between monthly Sunspots and ENSO data of two epochs (1996-2009 and 1950-2014). Corresponding transition matrices of both data sets appear similar and it is qualitatively evaluated by high values of 2-dimensional correlation found between transition matrices of ENSO and Sunspots. The associated transition diagrams show that each state communicates with the others. Presence of stronger self-communication (between same states) confirms periodic behaviour among the states. Moreover, closeness found in the expected number of visits from one state to the other show the existence of a possible relation between Sunspots and ENSO data. Moreover, perfect validation of dependency and stationary tests endorses the applicability of the Markov chain analyses on Sunspots and ENSO data. This shows that a significant relation between Sunspots and ENSO data exists. Improved understanding and modelling of Sunspots variations can help to explore the information about the related variables. This study can be useful to explore the influence of ENSO related local climatic variability.

  3. Observations of sunspot umbral velocity oscillations.

    NASA Technical Reports Server (NTRS)

    Bhatnagar, A.; Livingston, W. C.; Harvey, J. W.

    1972-01-01

    Review of sunspot umbral velocity measurements obtained free from any cross talk introduced by photospheric and penumbral scattered light by using lines formed only in the sunspot umbrae and showing no Zeeman effect. The maximum peak-to-peak amplitude of the umbral oscillatory velocity component is found to be of the order of 0.5 km per sec.

  4. Development of a Code to Analyze the Solar White-Light Images from the Kodaikanal Observatory: Detection of Sunspots, Computation of Heliographic Coordinates and Area

    NASA Astrophysics Data System (ADS)

    Pucha, Ragadeepika; Hiremath, K. M.; Gurumath, Shashanka R.

    2016-03-01

    Sunspots are the most conspicuous aspects of the Sun. They have a lower temperature, as compared to the surrounding photosphere; hence, sunspots appear as dark regions on a brighter background. Sunspots cyclically appear and disappear with a 11-year periodicity and are associated with a strong magnetic field ( ˜103 G) structure. Sunspots consist of a dark umbra, surrounded by a lighter penumbra. Study of umbra-penumbra area ratio can be used to give a rough idea as to how the convective energy of the Sun is transported from the interior, as the sunspot's thermal structure is related to this convective medium. An algorithm to extract sunspots from the white-light solar images obtained from the Kodaikanal Observatory is proposed. This algorithm computes the radius and center of the solar disk uniquely and removes the limb darkening from the image. It also separates the umbra and computes the position as well as the area of the sunspots. The estimated results are compared with the Debrecen photoheliographic results. It is shown that both area and position measurements are in quite good agreement.

  5. Helioseismology of a Realistic Magnetoconvective Sunspot Simulation

    NASA Technical Reports Server (NTRS)

    Braun, D. C.; Birch, A. C.; Rempel, M.; Duvall, T. L., Jr.

    2012-01-01

    We compare helioseismic travel-time shifts measured from a realistic magnetoconvective sunspot simulation using both helioseismic holography and time-distance helioseismology, and measured from real sunspots observed with the Helioseismic and Magnetic Imager instrument on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observatory. We find remarkable similarities in the travel-time shifts measured between the methodologies applied and between the simulated and real sunspots. Forward modeling of the travel-time shifts using either Born or ray approximation kernels and the sound-speed perturbations present in the simulation indicates major disagreements with the measured travel-time shifts. These findings do not substantially change with the application of a correction for the reduction of wave amplitudes in the simulated and real sunspots. Overall, our findings demonstrate the need for new methods for inferring the subsurface structure of sunspots through helioseismic inversions.

  6. HELIOSEISMOLOGY OF A REALISTIC MAGNETOCONVECTIVE SUNSPOT SIMULATION

    SciTech Connect

    Braun, D. C.; Birch, A. C.; Rempel, M.; Duvall, T. L. Jr. E-mail: aaronb@cora.nwra.com E-mail: Thomas.L.Duvall@nasa.gov

    2012-01-01

    We compare helioseismic travel-time shifts measured from a realistic magnetoconvective sunspot simulation using both helioseismic holography and time-distance helioseismology, and measured from real sunspots observed with the Helioseismic and Magnetic Imager instrument on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observatory. We find remarkable similarities in the travel-time shifts measured between the methodologies applied and between the simulated and real sunspots. Forward modeling of the travel-time shifts using either Born or ray approximation kernels and the sound-speed perturbations present in the simulation indicates major disagreements with the measured travel-time shifts. These findings do not substantially change with the application of a correction for the reduction of wave amplitudes in the simulated and real sunspots. Overall, our findings demonstrate the need for new methods for inferring the subsurface structure of sunspots through helioseismic inversions.

  7. Geographically selective assortment of cycles in pandemics: meta-analysis of data collected by Chizhevsky

    PubMed Central

    Gumarova, L.; Cornélissen, G.; Hillman, D.; Halberg, F.

    2013-01-01

    SUMMARY In the incidence patterns of cholera, diphtheria and croup during the past when they were of epidemic proportions, we document a set of cycles (periods), one of which was reported and discussed by A. L. Chizhevsky in the same data with emphasis on the mirroring in human disease of the ~11-year sunspot cycle. The data in this study are based on Chizhevsky’s book The Terrestrial Echo of Solar Storms and on records from the World Health Organization. For meta-analysis, we used the extended linear and nonlinear cosinor. We found a geographically selective assortment of various cycles characterizing the epidemiology of infections, which is the documented novel topic of this paper, complementing the earlier finding in the 21st century or shortly before, of a geographically selective assortment of cycles characterizing human sudden cardiac death. Solar effects, if any, interact with geophysical processes in contributing to this assortment. PMID:23228468

  8. On Mid-Term Periodicities in Sunspot Groups and Flare Index

    NASA Astrophysics Data System (ADS)

    Mendoza, Blanca; Velasco-Herrera, Víctor Manuel

    2011-07-01

    In this work we study the mid-term periodicities (MTPs), between 1 and 2 years, of the sunspot groups and the flare index (FI), by separating the data into hemispheres and spectral bands (SBs) according to the most significant periodicities presented by these phenomena. We found that the MTP of sunspot groups has a diminished power during the Modern Minimum and an increased power during the Modern Maximum, with the exception of cycle 20. For flares, the MTP has a diminished power during the low activity cycle 20, and an increased power during cycles 21 and 22. Therefore, for both sunspot groups and FI, cycle 20 shows a very diminished power followed by the active and higher-power cycles 21 and 22; cycle 23 shows a weaker power than cycles 21 and 22. It is uncertain whether MTP can be a precursor of a long-term minimum of solar activity or not, as has been previously suggested. Also, there is no one-to-one correlation between the cycle intensity and the importance of MTP. Concerning the quasi-biennial periodicities and the theory of two kinds of dynamos, we notice the tendency that higher-power cycles mean weaker coupling in the model. Concerning the hemispheric north-south asymmetry, for sunspot groups the southern hemisphere dominates in most of the SBs, while for FI the northern hemisphere dominates for all the SBs. Additionally, the time lag found between the two hemispheres indicates that the degrees of coupling in the photosphere for sunspot groups and in the corona for flares are between moderate and strong. Finally, the modulation shown by the MTP time series suggests that these periodicities are the product of chaotic quasi-periodic processes and not of stochastic processes.

  9. Variation in sunspot properties between 1999 and 2011 as observed with the Tenerife Infrared Polarimeter

    NASA Astrophysics Data System (ADS)

    Rezaei, R.; Beck, C.; Schmidt, W.

    2012-05-01

    Aims: We study the variation in the magnetic field strength and the umbral intensity of sunspots during the declining phase of the solar cycle No. 23 and in the beginning of cycle No. 24. Methods: We analyze a sample of 183 sunspots observed from 1999 until 2011 with the Tenerife Infrared Polarimeter (TIP) at the German Vacuum Tower Telescope (VTT). The magnetic field strength is derived from the Zeeman splitting of the Stokes-V signal in one near-infrared spectral line, either Fe i 1564.8 nm, Fe i 1089.6 nm, or Si i 1082.7 nm. This avoids the effects of the unpolarized stray light from the field-free quiet Sun surroundings that can affect the splitting seen in Stokes-I in the umbra. The minimum umbral continuum intensity and umbral area are also measured. Results: We find that there is a systematic trend for sunspots in the late stage of the solar cycle No. 23 to be weaker, i.e., to have a smaller maximum magnetic field strength than those at the start of the cycle. The decrease in the field strength with time of about 94 Gyr-1 is well beyond the statistical fluctuations that would be expected because of the larger number of sunspots close to cycle maximum (14 Gyr-1). In the same time interval, the continuum intensity of the umbra increases with a rate of 1.3 (±0.4)% of Ic yr-1, while the umbral area does not show any trend above the statistical variance. Sunspots in the new cycle No. 24 show higher field strengths and lower continuum intensities than those at the end of cycle No. 23, interrupting the trend. Conclusions: Sunspots have an intrinsically weaker field strength and brighter umbrae at the late stages of solar cycles compared to their initial stages, without any significant change in their area. The abrupt increase in field strength in sunspots of the new cycle suggests that the cyclic variations are dominating over any long-term trend that continues across cycles. We find a slight decrease in field strength and an increase in intensity as a long

  10. The Impact of the Revised Sunspot Record on Solar Irradiance Reconstructions

    NASA Astrophysics Data System (ADS)

    Kopp, G.; Krivova, N.; Wu, C. J.; Lean, J.

    2016-11-01

    Reliable historical records of the total solar irradiance (TSI) are needed to assess the extent to which long-term variations in the Sun's radiant energy that is incident upon Earth may exacerbate (or mitigate) the more dominant warming in recent centuries that is due to increasing concentrations of greenhouse gases. We investigate the effects that the new Sunspot Index and Long-term Solar Observations (SILSO) sunspot-number time series may have on model reconstructions of the TSI. In contemporary TSI records, variations on timescales longer than about a day are dominated by the opposing effects of sunspot darkening and facular brightening. These two surface magnetic features, retrieved either from direct observations or from solar-activity proxies, are combined in TSI models to reproduce the current TSI observational record. Indices that manifest solar-surface magnetic activity, in particular the sunspot-number record, then enable reconstructing historical TSI. Revisions of the sunspot-number record therefore affect the magnitude and temporal structure of TSI variability on centennial timescales according to the model reconstruction methods that are employed. We estimate the effects of the new SILSO record on two widely used TSI reconstructions, namely the NRLTSI2 and the SATIRE models. We find that the SILSO record has little effect on either model after 1885, but leads to solar-cycle fluctuations with greater amplitude in the TSI reconstructions prior. This suggests that many eighteenth- and nineteenth-century cycles could be similar in amplitude to those of the current Modern Maximum. TSI records based on the revised sunspot data do not suggest a significant change in Maunder Minimum TSI values, and from comparing this era to the present, we find only very small potential differences in the estimated solar contributions to the climate with this new sunspot record.

  11. Statistical Study on Personal Reduction Coefficients of Sunspot Numbers Since 1981

    NASA Astrophysics Data System (ADS)

    Cho, Il-Hyun; Bong, Su-Chan; Cho, Kyung-Suk; Lee, Jaejin; Kim, Rok-Soon; Park, Young-Deuk; Kim, Yeon-Han

    2014-12-01

    Using sunspot number data from 270 historical stations for the period 1981-2013, we investigate their personal reduction coefficients ($) statistically. Chang & Oh (2012) perform a simulation showing that the k varies with the solar cycle. We try to verify their results using observational data. For this, a weighted mean and weighted standard deviation of monthly sunspot number are used to estimate the error from observed data. We find that the observed error (noise) is much smaller than that used in the simulation. Thus no distinct k-variation with the solar cycle is observed contrary to the simulation. In addition, the probability distribution of k is determined to be non-Gaussian with a fat-tail on the right side. This result implies that the relative sunspot number after 1981 might be overestimated since the mean value of k is less than that of the Gaussian distribution.

  12. Sunspot dynamics are reflected in human physiology and pathophysiology.

    PubMed

    Hrushesky, William J M; Sothern, Robert B; Du-Quiton, Jovelyn; Quiton, Dinah Faith T; Rietveld, Wop; Boon, Mathilde E

    2011-03-01

    Periodic episodes of increased sunspot activity (solar electromagnetic storms) occur with 10-11 and 5-6 year periodicities and may be associated with measurable biological events. We investigated whether this sunspot periodicity characterized the incidence of Pap smear-determined cervical epithelial histopathologies and human physiologic functions. From January 1983 through December 2003, monthly averages were obtained for solar flux and sunspot numbers; six infectious, premalignant and malignant changes in the cervical epithelium from 1,182,421 consecutive, serially independent, screening Pap smears (59°9″N, 4°29″E); and six human physiologic functions of a healthy man (oral temperature, pulse, systolic and diastolic blood pressure, respiration, and peak expiratory flow), which were measured ∼5 times daily during ∼34,500 self-measurement sessions (44°56″N, 93°8″W). After determining that sunspot numbers and solar flux, which were not annually rhythmic, occurred with a prominent 10-year and a less-prominent 5.75-year periodicity during this 21-year study span, each biological data set was analyzed with the same curve-fitting procedures. All six annually rhythmic Pap smear-detected infectious, premalignant and malignant cervical epithelial pathologies showed strong 10-year and weaker 5.75-year cycles, as did all six self-measured, annually rhythmic, physiologic functions. The phases (maxima) for the six histopathologic findings and five of six physiologic measurements were very near, or within, the first two quarters following the 10-year solar maxima. These findings add to the growing evidence that solar magnetic storm periodicities are mirrored by cyclic phase-locked rhythms of similar period length or lengths in human physiology and pathophysiology.

  13. Sunspot Dynamics Are Reflected in Human Physiology and Pathophysiology

    NASA Astrophysics Data System (ADS)

    Hrushesky, William J. M.; Sothern, Robert B.; Du-Quiton, Jovelyn; Quiton, Dinah Faith T.; Rietveld, Wop; Boon, Mathilde E.

    2011-03-01

    Periodic episodes of increased sunspot activity (solar electromagnetic storms) occur with 10-11 and 5-6 year periodicities and may be associated with measurable biological events. We investigated whether this sunspot periodicity characterized the incidence of Pap smear-determined cervical epithelial histopathologies and human physiologic functions. From January 1983 through December 2003, monthly averages were obtained for solar flux and sunspot numbers; six infectious, premalignant and malignant changes in the cervical epithelium from 1,182,421 consecutive, serially independent, screening Pap smears (59°9"N, 4°29"E); and six human physiologic functions of a healthy man (oral temperature, pulse, systolic and diastolic blood pressure, respiration, and peak expiratory flow), which were measured ∼5 times daily during ∼34,500 self-measurement sessions (44°56"N, 93°8"W). After determining that sunspot numbers and solar flux, which were not annually rhythmic, occurred with a prominent 10-year and a less-prominent 5.75-year periodicity during this 21-year study span, each biological data set was analyzed with the same curve-fitting procedures. All six annually rhythmic Pap smear-detected infectious, premalignant and malignant cervical epithelial pathologies showed strong 10-year and weaker 5.75-year cycles, as did all six self-measured, annually rhythmic, physiologic functions. The phases (maxima) for the six histopathologic findings and five of six physiologic measurements were very near, or within, the first two quarters following the 10-year solar maxima. These findings add to the growing evidence that solar magnetic storm periodicities are mirrored by cyclic phase-locked rhythms of similar period length or lengths in human physiology and pathophysiology.

  14. Sunspot Dynamics Are Reflected in Human Physiology and Pathophysiology

    PubMed Central

    Sothern, Robert B.; Du-Quiton, Jovelyn; Quiton, Dinah Faith T.; Rietveld, Wop; Boon, Mathilde E.

    2011-01-01

    Abstract Periodic episodes of increased sunspot activity (solar electromagnetic storms) occur with 10–11 and 5–6 year periodicities and may be associated with measurable biological events. We investigated whether this sunspot periodicity characterized the incidence of Pap smear-determined cervical epithelial histopathologies and human physiologic functions. From January 1983 through December 2003, monthly averages were obtained for solar flux and sunspot numbers; six infectious, premalignant and malignant changes in the cervical epithelium from 1,182,421 consecutive, serially independent, screening Pap smears (59°9″N, 4°29″E); and six human physiologic functions of a healthy man (oral temperature, pulse, systolic and diastolic blood pressure, respiration, and peak expiratory flow), which were measured ∼5 times daily during ∼34,500 self-measurement sessions (44°56″N, 93°8″W). After determining that sunspot numbers and solar flux, which were not annually rhythmic, occurred with a prominent 10-year and a less-prominent 5.75-year periodicity during this 21-year study span, each biological data set was analyzed with the same curve-fitting procedures. All six annually rhythmic Pap smear-detected infectious, premalignant and malignant cervical epithelial pathologies showed strong 10-year and weaker 5.75-year cycles, as did all six self-measured, annually rhythmic, physiologic functions. The phases (maxima) for the six histopathologic findings and five of six physiologic measurements were very near, or within, the first two quarters following the 10-year solar maxima. These findings add to the growing evidence that solar magnetic storm periodicities are mirrored by cyclic phase-locked rhythms of similar period length or lengths in human physiology and pathophysiology. Key Words: Cervical infections—Cervical premalignancy—Geo-solar magnetic interactions—Pap smear—Schwabe cycle—10-year rhythm. Astrobiology 11, 93–103. PMID:21391821

  15. Modeling Repeatedly Flaring δ Sunspots

    NASA Astrophysics Data System (ADS)

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-01

    Active regions (ARs) appearing on the surface of the Sun are classified into α , β , γ , and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  16. Modeling Repeatedly Flaring δ Sunspots.

    PubMed

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-11

    Active regions (ARs) appearing on the surface of the Sun are classified into α, β, γ, and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  17. Electric current in a unipolar sunspot with an untwisted field

    NASA Technical Reports Server (NTRS)

    Osherovich, V. A.; Garcia, H. A.

    1990-01-01

    The return flux (RF) sunspot model is applied to a round, unipolar sunspot observed by H. Kawakami (1983). Solving the magnetohydrostatic problem using the gas pressure deficit between the umbral and quiet-sun atmospheres as a source function, a distribution of electric current density in an untwisted, unipolar sunspot as a function of height and radial distance from the sunspot center is observed. Maximum electric current density is about 32 mA/sq m at the bottom of the sunspot.

  18. Thermospheric density model biases at sunspot maximum

    NASA Astrophysics Data System (ADS)

    Pardini, Carmen; Moe, Kenneth; Anselmo, Luciano

    A previous study (Pardini C., Anselmo L, Moe K., Moe M.M., Drag and energy accommodation coefficients during sunspot maximum, Adv. Space Res., 2009, doi:10.1016/j.asr.2009.08.034), including ten satellites with altitudes between 200 and 630 km, has yielded values for the energy accommodation coefficient as well as for the physical drag coefficient as a function of height during solar maximum conditions. The results are consistent with the altitude and solar cycle variation of atomic oxygen, which is known to be adsorbed on satellite surfaces, affecting both the energy accommodation and angular distribution of the reemitted molecules. Taking advantage of these results, an investigation of thermospheric density model biases at sunspot maximum became possible using the recently upgraded CDFIT software code. Specif-ically developed at ISTI/CNR, CDFIT is used to fit the observed satellite semi-major axis decay. All the relevant orbital perturbations are considered and several atmospheric density models have been implemented over the years, including JR-71, MSISE-90, NRLMSISE-00, GOST2004 and JB2006. For this analysis we reused the satellites Cosmos 2265 and Cosmos 2332 (altitude: 275 km), SNOE (altitude: 480 km), and Clementine (altitude: 630 km), spanning the last solar cycle maximum (October 1999 -January 2003). For each satellite, and for each of the above men-tioned atmospheric density models, the fitted drag coefficient was obtained with CDFIT, using the observed orbital decay, and then compared with the corresponding physical drag coefficient estimated in the previous study (Pardini et al., 2009). It was consequently possible to derive the average density biases of the thermospheric models during the considered time span. The average results obtained for the last sunspot maximum can be summarized as follows (the sign "+" means that the atmospheric density is overestimated by the model, while the sign "-" means that the atmospheric density is underestimated

  19. Helioseismic imaging of sunspots at their antipodes

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles; Braun, Douglas C.

    1990-01-01

    Recent work by Braun et al. (1988) has shown that sunspots absorb helioseismic waves. It is proposed that sunspot absorption causes a seismic deficit that should be imaged at the antipode of the sunspot. If these images are observable, it should be possible to produce seismic maps of magnetic regions on the far side of the sun. Diagnostic applications would include lifetimes of higher-frequency modes, and possibly rotation of the solar interior and detection of subsurface magnetic structure. Elements of the theory of seismic imaging are outlined. The extention of acoustic holography to solar interior diagnostics in the context of antipodal imaging is proposed.

  20. Carotid Artery Stenting: Single-Center Experience Over 11 Years

    SciTech Connect

    Nolz, Richard Schernthaner, Ruediger Egbert; Cejna, Manfred; Schernthaner, Melanie Lammer, Johannes Schoder, Maria

    2010-04-15

    This article reports the results of carotid artery stenting during an 11-year period. Data from 168 carotid artery stenting procedures (symptomatic, n = 55; asymptomatic, n = 101; symptoms not accessible, n = 12) were retrospectively collected. Primary technical success rate, neurological events in-hospital, access-site complications, and contrast-induced nephropathy (n = 118) were evaluated. To evaluate the influence of experience in carotid artery stenting on intraprocedural neurologic complications, patients were divided into two groups. Group 1 included the first 80 treated patients, and group 2 the remainder of the patients (n = 88). In-stent restenoses at last-follow-up examinations (n = 89) were assessed. The overall primary technical success rate was 95.8%. The in-hospital stroke-death rate was 3.0% (n = 5; symptomatic, 5.4%; asymptomatic, 2.0%; p = 0.346). Neurologic complications were markedly higher in group 1 (4.2%; three major strokes; symptomatic, 2.8%, asymptomatic, 1.4%) compared to group 2 (2.4%; one major and one minor stroke-symptomatic, 1.2%, asymptomatic 1.2%), but this was not statistically significant. Further complications were access-site complications in 12 (7.1%), with surgical revision required in 1 (0.6%) and mild contrast-induced nephropathy in 1 (0.85%). Twenty-one (23.6%) patients had >50% in-stent restenosis during a mean follow-up of 28.2 months. In conclusion, advanced experience in carotid artery stenting leads to an acceptable periprocedural stroke-death rate. In-stent restenosis could be a critical factor during the follow-up course.

  1. Wavelet analysis of CME, X-ray flare, and sunspot series

    NASA Astrophysics Data System (ADS)

    Guedes, M. R. G.; Pereira, E. S.; Cecatto, J. R.

    2015-01-01

    Context. Coronal mass ejections (CMEs) and solar flares are the most energetic transient phenomena taking place at the Sun. Together they are principally responsible for disturbances in outer geospace. Coronal mass ejections and solar flares are believed to be correlated with the solar cycle, which is mainly characterized by sunspot numbers. Aims: Here, we search for pattern identification in CMEs, X-ray solar flares, and sunspot number time series using a new data mining process and a quantitative procedure to correlate these series. Methods: This new process consists of the combination of a decomposition method with the wavelet transform technique applied to the series ranging from 2000 until 2012. A simple moving average is used for the time-series decomposition as a high-pass filter. A continuous wavelet transform is applied to the series in sequence, which permits us to uncover signals previously masked by the original time series. We made use of the wavelet coherence to find some correlation between the data. Results: The results have shown the existence of periodic and intermittent signals in the CMEs, flares, and sunspot time series. For the CME and flare series, few and relatively short time intervals without any signal were observed. Signals with an intermittent character take place during some epochs of the maximum and descending phases of the solar cycle 23 and rising phase of solar cycle 24. A comparison among X-ray flares, sunspots, and CME time series shows a stronger relation between flare and CMEs, although during some short intervals (four-eight months) and in a relatively narrow band. Yet, in contrast we have obtained a fainter or even absent relation between the X-ray flares and sunspot number series as well as between the CMEs and sunspot number series.

  2. When Daily Sunspot Births Become Positively Correlated

    NASA Astrophysics Data System (ADS)

    Shapoval, Alexander; Le Mouël, Jean-Louis; Shnirman, Mikhail; Courtillot, Vincent

    2015-10-01

    We study the first differences w(t) of the International Sunspot Number (ISSN) daily series for the time span 1850 - 2013. The one-day correlations ρ1 between w(t) and w(t+1) are computed within four-year sliding windows and are found to shift from negative to positive values near the end of Cycle 17 ({˜} 1945). They remain positive during the last Grand Maximum and until {˜} 2009, when they fall to zero. We also identify a prominent regime change in {˜} 1915, strengthening previous evidence of major anomalies in solar activity at this date. We test an autoregressive process of order 1 (AR(1)) as a model that can reproduce the high-frequency component of ISSN: we compute ρ1 for this AR(1) process and find that it is negative. Positive values of ρ1 are found only if the process involves positive correlation: this leads us to suggest that the births of successive spots are positively correlated during the last Grand Maximum.

  3. Properties of a Decaying Sunspot

    NASA Astrophysics Data System (ADS)

    Balthasar, H.; Beck, C.; Gömöry, P.; Muglach, K.; Puschmann, K. G.; Shimizu, T.; Verma, M.

    A small decaying sunspot was observed with the Vacuum Tower Telescope (VTT) on Tenerife and the Japanese Hinode satellite. We obtained full Stokes scans in several wavelengths covering different heights in the solar atmosphere. Imaging time series from Hinode and the Solar Dynamics Observatory (SDO) complete our data sets. The spot is surrounded by a moat flow, which persists also on that side of the spot where the penumbra already had disappeared. Close to the spot, we find a chromospheric location with downflows of more than 10 km s^{-1} without photospheric counterpart. The height dependence of the vertical component of the magnetic field strength is determined in two different ways that yielded different results in previous investigations. Such a difference still exists in our present data, but it is not as pronounced as in the past.

  4. The sunspot databases of the Debrecen Observatory

    NASA Astrophysics Data System (ADS)

    Baranyi, Tünde; Gyori, Lajos; Ludmány, András

    2015-08-01

    We present the sunspot data bases and online tools available in the Debrecen Heliophysical Observatory: the DPD (Debrecen Photoheliographic Data, 1974 -), the SDD (SOHO/MDI-Debrecen Data, 1996-2010), the HMIDD (SDO/HMI-Debrecen Data, HMIDD, 2010-), the revised version of Greenwich Photoheliographic Data (GPR, 1874-1976) presented together with the Hungarian Historical Solar Drawings (HHSD, 1872-1919). These are the most detailed and reliable documentations of the sunspot activity in the relevant time intervals. They are very useful for studying sunspot group evolution on various time scales from hours to weeks. Time-dependent differences between the available long-term sunspot databases are investigated and cross-calibration factors are determined between them. This work has received funding from the European Community's Seventh Framework Programme (FP7/2012-2015) under grant agreement No. 284461 (eHEROES).

  5. Theories of dynamical phenomena in sunspots

    NASA Technical Reports Server (NTRS)

    Thomas, J. H.

    1981-01-01

    Attempts that have been made to understand and explain observed dynamical phenomena in sunspots within the framework of magnetohydrodynamic theory are surveyed. The qualitative aspects of the theory and physical arguments are emphasized, with mathematical details generally avoided. The dynamical phenomena in sunspots are divided into two categories: aperiodic (quasi-steady) and oscillatory. For each phenomenon discussed, the salient observational features that any theory should explain are summarized. The two contending theoretical models that can account for the fine structure of the Evershed motion, namely the convective roll model and the siphon flow model, are described. With regard to oscillatory phenomena, attention is given to overstability and oscillatory convection, umbral oscillations and flashes. penumbral waves, five-minute oscillations in sunspots, and the wave cooling of sunspots.

  6. Sunspot temperatures from red and blue photometry

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

    Photometric images are used to measure the temperature of sunspots at different wavelengths. Images at 672.3 nm and 472.3 nm are obtained at the San Fernando Observatory using the CFDT2 (2.5'' x 2.5'' pixels). Images at 607.1 nm and 409.4 nm are obtained by the PSPT at Mauna Loa Observatory. Monochromatic intensities are converted to temperatures as in Steinegger et al (1990). The pixel by pixel temperature for a sunspot is converted into a bolometric contrast for that sunspot according to Chapman et al (1994). Sunspot temperatures, i.e., their bolometric contrasts, are calculated from both red (672.3 nm) and blue wavelengths (472.3 nm) and compared.

  7. Sunspot Cycle 24: Smallest Cycle in 100 Years?

    DTIC Science & Technology

    2005-01-11

    are _W taken to be a measure of how well the procedure works (the oun* Wilson Solor Obs. Wico ,*Uf ts,. only real measure as far as we are concerned...Sun’s magnetic field, planetary magnetic field strength, solar wind speed and EUV irradiance, 1952-1954, Astrophys. J., 121, 349. 1890-2003, in Solar

  8. Bimodal Distribution of Magnetic Fields and Areas of Sunspots

    NASA Astrophysics Data System (ADS)

    Tlatov, Andrey G.; Pevtsov, Alexei A.

    2014-04-01

    We applied automatic identification of sunspot umbrae and penumbrae to daily observations from the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) to study their magnetic flux density ( B) and area ( A). The results confirm an already known logarithmic relationship between the area of sunspots and their maximum flux density. In addition, we find that the relation between average magnetic flux density () and sunspot area shows a bimodal distribution: for small sunspots and pores ( A≤20 millionth of solar hemisphere, MSH), (gauss), and for large sunspots ( A≥100 MSH), is about 600 G. For intermediate sunspots, average flux density linearly decreases from about 800 G to 600 G. A similar bimodal distribution was found in several other integral parameters of sunspots. We show that this bimodality can be related to different stages of sunspot penumbra formation and can be explained by the difference in average inclination of magnetic fields at the periphery of small and large sunspots.

  9. Magnetic field reconstruction based on sunspot oscillations

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, J.; Bello González, N.; Schmidt, W.

    2016-11-01

    The magnetic field of a sunspot guides magnetohydrodynamic waves toward higher atmospheric layers. In the upper photosphere and lower chromosphere, wave modes with periods longer than the acoustic cut-off period become evanescent. The cut-off period essentially changes due to the atmospheric properties, e.g., increases for larger zenith inclinations of the magnetic field. In this work, we aim at introducing a novel technique of reconstructing the magnetic field inclination on the basis of the dominating wave periods in the sunspot chromosphere and upper photosphere. On 2013 August 21, we observed an isolated, circular sunspot (NOAA11823) for 58 min in a purely spectroscopic multi-wavelength mode with the Interferometric Bidimensional Spectro-polarimeter (IBIS) at the Dunn Solar Telescope. By means of a wavelet power analysis, we retrieved the dominating wave periods and reconstructed the zenith inclinations in the chromosphere and upper photosphere. The results are in good agreement with the lower photospheric HMI magnetograms. The sunspot's magnetic field in the chromosphere inclines from almost vertical (0°) in the umbra to around 60° in the outer penumbra. With increasing altitude in the sunspot atmosphere, the magnetic field of the penumbra becomes less inclined. We conclude that the reconstruction of the magnetic field topology on the basis of sunspot oscillations yields consistent and conclusive results. The technique opens up a new possibility to infer the magnetic field inclination in the solar chromosphere.

  10. Preface to Topical Issue: Recalibration of the Sunspot Number

    NASA Astrophysics Data System (ADS)

    Clette, F.; Cliver, E. W.; Lefèvre, L.; Svalgaard, L.; Vaquero, J. M.; Leibacher, J. W.

    2016-11-01

    This topical issue contains articles on the effort to recalibrat e the sunspot number (SN) that was initiated by the Sunspot Number Workshops. These workshops led to a revision of the Wolf sunspot number (WSN) and a new construction of the group sunspot number (GSN), both published herein. In addition, this topical issue includes three independently proposed alternative SN time series (two Wolf and one group), as well as articles providing historical context, critical assessments, correlative analyses, and observational data, both historical and modern, pertaining to the sunspot-number time series. The ongoing effort to understand and reconcile the differences between the various new sunspot number series is briefly discussed.

  11. Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Owens, M. J.; Barnard, L.; Scott, C. J.; Usoskin, I. G.; Nevanlinna, H.

    2016-11-01

    We compare four sunspot-number data sequences against geomagnetic and terrestrial auroral observations. The comparisons are made for the original Solar Influences Data Center (SIDC) composite of Wolf/Zürich/International sunspot number [R_{{ISNv}1}], the group sunspot number [RG] by Hoyt and Schatten ( Solar Phys. 181, 491, 1998), the new "backbone" group sunspot number [R_{BB}] by Svalgaard and Schatten ( Solar Phys., DOI: 10.1007/s11207-015-0815-8, 2016), and the "corrected" sunspot number [RC] by Lockwood, Owens, and Barnard ( J. Geophys. Res. 119, 5172, 2014a). Each sunspot number is fitted with terrestrial observations, or parameters derived from terrestrial observations to be linearly proportional to sunspot number, over a 30-year calibration interval of 1982 - 2012. The fits are then used to compute test sequences, which extend further back in time and which are compared to R_{{ISNv}1}, RG, R_{{BB}}, and RC. To study the long-term trends, comparisons are made using averages over whole solar cycles (minimum-to-minimum). The test variations are generated in four ways: i) using the IDV(1d) and IDV geomagnetic indices (for 1845 - 2013) fitted over the calibration interval using the various sunspot numbers and the phase of the solar cycle; ii) from the open solar flux (OSF) generated for 1845 - 2013 from four pairings of geomagnetic indices by Lockwood et al. ( Ann. Geophys. 32, 383, 2014a) and analysed using the OSF continuity model of Solanki, Schüssler, and Fligge ( Nature, 408, 445, 2000), which employs a constant fractional OSF loss rate; iii) the same OSF data analysed using the OSF continuity model of Owens and Lockwood ( J. Geophys. Res. 117, A04102, 2012), in which the fractional loss rate varies with the tilt of the heliospheric current sheet and hence with the phase of the solar cycle; iv) the occurrence frequency of low-latitude aurora for 1780 - 1980 from the survey of Legrand and Simon ( Ann. Geophys. 5, 161, 1987). For all cases, R_{BB} exceeds

  12. 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.

  13. 11-Year cyclicity of the near-surface heat flux at the Vostok station

    NASA Astrophysics Data System (ADS)

    Volobuev, D. M.

    2013-12-01

    It is known that the solar component is difficult to find in a climatic signal due to its small size and significant internal random disturbances of the climatic system, such as variations in cloudiness, precipitation, winds, and oceanic currents. In the center of the polar cap, these disturbances are as minimal as possible; therefore, solving the inverse heat conduction problem, we can calculate the informative heat flux through the ice cover based on temperature data. Variations in the heat flux are quite significant in amplitude (0.2-0.3 W/m2) and coincide with the 11-year solar cycle in phase. Application of this approach to the indices of the global and sea surface temperatures cannot yield a solar signal, yet it can be traced for solar cycles with big amplitude (cycles 19 and 21). Thus, the found variation in the heat flux is most probably caused by a change in the solar constant (TSI); however, other mechanisms are also possible.

  14. Solar small-scale dynamo and polarity of sunspot groups

    NASA Astrophysics Data System (ADS)

    Sokoloff, D.; Khlystova, A.; Abramenko, V.

    2015-08-01

    In order to clarify a possible role of small-scale dynamo in formation of solar magnetic field, we suggest an observational test for small-scale dynamo action based on statistics of anti-Hale sunspot groups. As we have shown, according to theoretical expectations the small-scale dynamo action has to provide a population of sunspot groups which do not follow the Hale polarity law, and the density of such groups on the time-latitude diagram is expected to be independent on the phase of the solar cycle. Correspondingly, a percentage of the anti-Hale groups is expected to reach its maximum values during solar minima. For several solar cycles, we considered statistics of anti-Hale groups obtained by several scientific teams, including ours, to find that the percentage of anti-Hale groups becomes indeed maximal during a solar minimum. Our interpretation is that this fact may be explained by the small-scale dynamo action inside the solar convective zone.

  15. Sunspot drawings handwritten character recognition method based on deep learning

    NASA Astrophysics Data System (ADS)

    Zheng, Sheng; Zeng, Xiangyun; Lin, Ganghua; Zhao, Cui; Feng, Yongli; Tao, Jinping; Zhu, Daoyuan; Xiong, Li

    2016-05-01

    High accuracy scanned sunspot drawings handwritten characters recognition is an issue of critical importance to analyze sunspots movement and store them in the database. This paper presents a robust deep learning method for scanned sunspot drawings handwritten characters recognition. The convolution neural network (CNN) is one algorithm of deep learning which is truly successful in training of multi-layer network structure. CNN is used to train recognition model of handwritten character images which are extracted from the original sunspot drawings. We demonstrate the advantages of the proposed method on sunspot drawings provided by Chinese Academy Yunnan Observatory and obtain the daily full-disc sunspot numbers and sunspot areas from the sunspot drawings. The experimental results show that the proposed method achieves a high recognition accurate rate.

  16. An Alternative Measure of Solar Activity from Detailed Sunspot Datasets

    NASA Astrophysics Data System (ADS)

    Muraközy, J.; Baranyi, T.; Ludmány, A.

    2016-11-01

    The sunspot number is analyzed by using detailed sunspot data, including aspects of observability, sunspot sizes, and proper identification of sunspot groups as discrete entities of solar activity. The tests show that in addition to the subjective factors there are also objective causes of the ambiguities in the series of sunspot numbers. To introduce an alternative solar-activity measure, the physical meaning of the sunspot number has to be reconsidered. It contains two components whose numbers are governed by different physical mechanisms and this is one source of the ambiguity. This article suggests an activity index, which is the amount of emerged magnetic flux. The only long-term proxy measure is the detailed sunspot-area dataset with proper calibration to the magnetic flux. The Debrecen sunspot databases provide an appropriate source for the establishment of the suggested activity index.

  17. Short-Term Variations in the Equatorial Rotation Rate of Sunspot Groups

    NASA Astrophysics Data System (ADS)

    Javaraiah, J.; Bertello, L.

    2016-12-01

    We have detected several periodicities in the solar equatorial rotation rate of sunspot groups in the catalog Greenwich Photoheliographic Results (GPR) during the period 1931 - 1976, the Solar Optical Observing Network (SOON) during the period 1977 - 2014, and the Debrecen Photoheliographic Data (DPD) during the period 1974 - 2014. We have compared the results from the fast Fourier transform (FFT), the maximum entropy method (MEM), and the Morlet wavelet power-spectra of the equatorial rotation rates determined from SOON and DPD sunspot-group data during the period 1986 - 2007 with those of the Mount Wilson Doppler-velocity data during the same period determined by Javaraiah et al. ( Solar Phys. 257, 61, 2009). We have also compared the power-spectra computed from the DPD and the combined GPR and SOON sunspot-group data during the period 1974 - 2014 to those from the GPR sunspot-group data during the period 1931 - 1973. Our results suggest a ˜ 250-day period in the equatorial rotation rate determined from both the Mt. Wilson Doppler-velocity data and the sunspot-group data during 1986 - 2007. However, a wavelet analysis reveals that this periodicity appears mostly around 1991 in the velocity data, while it is present in most of the solar cycles covered by the sunspot-group data, mainly near the minimum epochs of the solar cycles. We also found the signature of a period of ˜ 1.4 years in the velocity data during 1990 - 1995, and in the equatorial rotation rate of sunspot groups mostly around the year 1956. The equatorial rotation rate of sunspot groups reveals a strong ˜ 1.6-year periodicity around 1933 and 1955, a weaker one around 1976, and a strong ˜ 1.8-year periodicity around 1943. Our analysis also suggests periodicities of ˜ 5 years, ˜ 7 years, and ˜ 17 years, as well as some other short-term periodicities. However, short-term periodicities are mostly present at the time of solar minima. Hence, short-term periodicities cannot be confirmed because of

  18. New calibrated sunspot group series since 1749

    NASA Astrophysics Data System (ADS)

    Usoskin, Ilya; Kovaltsov, Gennady; Lockwood, Michael; Mursula, Kalevi; Owens, Matthew; Sonaki, Sami

    2016-04-01

    The largest uncertainty of the long sunspot-number series is related to the "calibration" of the visual acuity of individual observers in the past. A traditional way for such calibration is a daisy-chain regression method, which may lead to significant bias and error accumulation. Here we present a novel method for calibrating the visual acuity of the key solar observers to the reference data set of the Royal Greenwich Observatory sunspot groups for the period 1900 - 1976, using the statistics of the active-day fraction. The observational thresholds is defined for each observer relative to the reference data set. As a result, a new calibrated series of sunspot group numbers is obtained, without any daisy-chain regression. The new series displays secular minima around 1800 (Dalton Minimum) and 1900 (Gleissberg Minimum), as well as the Modern Grand Maximum of activity in the second half of the twentieth century. The new result is fully consistent with the 'classical' group sunspot number series (Hoyt and Schatten, 1998) after 1830 but suggests a slightly higher activity before 1830. On the other hand, the new result implies that a recent correction by Clette et al. (2014) and Svalgaard and Schatten (2016) overestimated sunspot activity before 1900.

  19. Does sunspot numbers cause global temperatures? A reconsideration using non-parametric causality tests

    NASA Astrophysics Data System (ADS)

    Hassani, Hossein; Huang, Xu; Gupta, Rangan; Ghodsi, Mansi

    2016-10-01

    In a recent paper, Gupta et al., (2015), analyzed whether sunspot numbers cause global temperatures based on monthly data covering the period 1880:1-2013:9. The authors find that standard time domain Granger causality test fails to reject the null hypothesis that sunspot numbers do not cause global temperatures for both full and sub-samples, namely 1880:1-1936:2, ​1936:3-1986:11 and 1986:12-2013:9 (identified based on tests of structural breaks). However, frequency domain causality test detects predictability for the full-sample at short (2-2.6 months) cycle lengths, but not the sub-samples. But since, full-sample causality cannot be relied upon due to structural breaks, Gupta et al., (2015) conclude that the evidence of causality running from sunspot numbers to global temperatures is weak and inconclusive. Given the importance of the issue of global warming, our current paper aims to revisit this issue of whether sunspot numbers cause global temperatures, using the same data set and sub-samples used by Gupta et al., (2015), based on an nonparametric Singular Spectrum Analysis (SSA)-based causality test. Based on this test, we however, show that sunspot numbers have predictive ability for global temperatures for the three sub-samples, over and above the full-sample. Thus, generally speaking, our non-parametric SSA-based causality test outperformed both time domain and frequency domain causality tests and highlighted that sunspot numbers have always been important in predicting global temperatures.

  20. Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing

    DTIC Science & Technology

    2009-08-28

    climatological off-equatorial tropical precipitation maxima in the Pacific, lower the eastern equatorial Pacific sea surface temperatures during peaks...with an associated increase in trade wind strength that produces greater equa- torial ocean upwelling and lower equatorial SSTs in the eastern ...Pacific, a signal that was first discovered in observational data (1, 2). The en- hanced subsidence produces fewer clouds in the equatorial eastern Pacific

  1. 11-year solar cycle in Schumann resonance data as observed in Antarctica

    NASA Astrophysics Data System (ADS)

    Nickolaenko, A. P.; Koloskov, A. V.; Hayakawa, M.; Yampolski, Yu. M.; Budanov, O. V.; Korepanov, V. E.

    2015-03-01

    Studies of Schumann resonance allows obtaining characteristics of the lower ionosphere and the dynamics of global thunderstorms based on the data recorded at a single or a few ground-based observatories. We use the simple model of a point source. The vertical profile of air conductivity is described by the "knee" model. We used continuous Schumann resonance record from the "Akademik Vernadsky" Ukrainian Antarctic station (geographic coordinates: 65.25S and 64.25W, L=2.6). A data processing show that the north-south seasonal drift of global thunderstorms was about 20°, and the intensity of global lightning activity changed annually by the factor 1.5-2. Unequal duration of the "electromagnetic" seasons was confirmed ("summer" ~ 120 days, "winter" ~ 60 days; duration of the "spring" is shorter than the "fall"). A possible explanation of inter-annual variations of Schumann resonance parameter follows from changes in the effective height of the lower ionosphere. In this case, we used the spatial thunderstorm distribution following from the annual data of the Optical Transient Detector satellite. We show that recorded inter-annual variations of resonance frequencies and intensities might be attributed to 1-2 km alterations in the knee height of ionosphere. The most realistic mechanism of changes should include both the height variations and the drift of global thunderstorms. Both the processes are governed by solar activity. We also estimated the feasible trend in the equatorial soil surface temperature by 1.6° C corresponding to the inter-annual change of Schumann resonance intensity.

  2. A Comparison of Rome Observatory Sunspot Area and Sunspot Number Determinations With International Measures, 1958-1998

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2005-01-01

    Two changes in recording the sunspot record have occurred in recent years. First, in 1976, the longer-than-100-yr daily photographic record of the Royal Greenwich Observatory (RGO), used for determination of numbers and positions of sunspot groups and sunspot areas ended, and second, at the end of 1980, after more than 130 years, Zurich s Swiss Federal Observatory stopped providing daily sunspot numbers. To extend the sunspot record beyond 1976, use of United States Air Force/National Oceanic and Atmospheric Administration (USAF/NOAA) sunspot drawing observations from the Solar Optical Observing Network began in 1977, and the combined record of sunspot activity from RGO/USAF/NOAA was made accessible at http://science.nasa.gov/ssl/PAD/SOLAR/greenwch.htm. Also, in 1981, the task of providing daily sunspot numbers was taken up by the Royal Observatory of Belgium s Solar Influences and Data analysis Center, and the combined Zurich/International sunspot number database was made available at http://sidc.oma.be/index.php3. In this study, Rome Observatory 1958-1998 photographic records of sunspot areas, numbers of groups, and derived sunspot numbers are compared against same-day international values to determine relative behaviors and to evaluate whether any potential changes might have been introduced in the overall sunspot record, due to the aforementioned changes.

  3. Sunspot waves and flare energy release

    NASA Astrophysics Data System (ADS)

    Sych, R.; Karlický, M.; Altyntsev, A.; Dudík, J.; Kashapova, L.

    2015-05-01

    Context. We study the possibility of flare process triggering by waves propagating from the sunspot along a magnetic loop (channel) to a nearby flare site. Aims: We present a relationship between the dynamics of ~3-min slow magnetoacoustic waves in the sunspot and flare emergence process. Waves propagating in the magnetic channel whose one foot is anchored in the umbra represent the disturbing agent responsible for triggering the flare energy release. Methods: We applied time-distance plots and pixel wavelet filtration methods to obtain spatio-temporal distribution of wave power variations in radio and SDO/AIA data. To find the magnetic channel, we used potential magnetic field extrapolation of SDO/HMI magnetograms. The propagation velocity of wave fronts was measured from wave locations at specific times. Results: In the correlation curves of the 17 GHz (NoRH) radio emission, we found a monotonous energy amplification of the 3-min waves in the sunspot umbra before the 2012 June 7 flare. This amplification was associated with an increase in the length of the oscillatory wakes in coronal loops (SDO/AIA, 171 Å) prior to the flare onset. A peculiarity of the flare is the constant level of the flare emission in soft X-rays (RHESSI, 3-25 keV) for ~10 min after the short impulsive phase, which indicates continuing energy release. Throughout this time, we found transverse oscillations of the flare loop with a 30 s period in the radio-frequency range (NoRH, 17 GHz). This period appears to be related to the 3-min waves from the sunspot. The magnetic field extrapolation based on SDO/HMI magnetograms shows the existence of the magnetic channel (waveguide) connecting the sunspot with the energy release region. Conclusions: We analysed the sunspot 3-min wave dynamics and found a correlation between the oscillation power amplification and flare triggering in the region connected to the sunspot through the magnetic channel. We propose that this amplified wave flux triggered the

  4. Evidence for Magnetoconvection in Sunspot Umbral Dots

    NASA Astrophysics Data System (ADS)

    Bharti, Lokesh; Jain, Rajmal; Jaaffrey, S. N. A.

    2007-08-01

    An analysis of high-resolution Dopplergrams and continuum images of NOAA AR 8350 is presented. The observations were recorded with the universal birefringent filter attached to the Dunn Solar Telescope at the National Solar Observatory, Sunspot, New Mexico. We find upward velocity of the order of 400 m s-1 within umbral dots, surrounded by downward velocity of the order of 300 m s-1. This observation is compatible with the simulations of three-dimensional radiative magnetoconvection with gray radiative transfer in sunspot umbra by Schüssler & Vögler, which support the idea that umbral dots appear as a result of magnetoconvection.

  5. Phase relationship between the relative sunspot numbers and solar mean magnetic field

    NASA Astrophysics Data System (ADS)

    Yin, Zq; Han, YB

    2015-08-01

    Short-term variations of the solar mean magnetic field (SMMF) were investigated through re-analyzing the data from the Wilcox Solar Observatory during the last four solar activity cycles using continuous wavelet transforms. We demonstrated the time-variable characters of short-term periods of SMMF. Our results indicate that the SMMF has main periods of about 27 and 13.5 days not only in the minimum and maximum years of each activity cycle, but also in the increase and decrease of the solar cycle. The entire time span of SMMF was investigated and discussed further (DOI 10.1007/s11434-014-0594-x). Sunspot numbers (SSN) are caused by intense magnetic activity, and they are associated with strong magnetic fields in active region, while SMMF describe the large-scale manifestations of solar magnetism. The continuous wavelet, cross wavelet, and wavelet coherence analyses, are employed to clarify the phase relationship between the daily and smoothed monthly mean sunspot number and SMMF. Analysis shows that there is a region of high spectral power sitting across the Schwabe cycle belt, where the SSN lead the SMMF by about 10 months. However, analysis of the cross-wavelet transform and wavelet coherence unveils asynchronous behavior featured with phase mixing in the high-frequency components of SSN and SMMF, The time-variable characteristics of periods of SMMF and sunspots and their cross-relations are investigated and discussed during the different phase of solar cycles.

  6. Two regimes in the regularity of sunspot number

    SciTech Connect

    Shapoval, A.; Shnirman, M.

    2013-12-20

    Sunspot numbers WN display quasi-periodical variations that undergo regime changes. These irregularities could indicate a chaotic system and be measured by Lyapunov exponents. We define a functional λ (an 'irregularity index') that is close to the (maximal) Lyapunov exponent for dynamical systems and well defined for series with a random component: this allows one to work with sunspot numbers. We compute λ for the daily WN from 1850 to 2012 within 4 yr sliding windows: λ exhibit sharp maxima at solar minima and secondary maxima at solar maxima. This pattern is reflected in the ratio R of the amplitudes of the main versus secondary peaks. Two regimes have alternated in the past 150 yr, R1 from 1850 to 1915 (large λ and R values) and R2 from 1935 to 2005 (shrinking difference between main and secondary maxima, R values between 1 and 2). We build an autoregressive model consisting of Poisson noise plus an 11 yr cycle and compute its irregularity index. The transition from R1 to R2 can be reproduced by strengthening the autocorrelation a of the model series. The features of the two regimes are stable for model and WN with respect to embedding dimension and delay. Near the time of the last solar minimum (∼2008), the irregularity index exhibits a peak similar to the peaks observed before 1915. This might signal a regime change back from R2 to R1 and the onset of a significant decrease of solar activity.

  7. Are secular correlations between sunspots, geomagnetic activity, and global temperature significant?

    USGS Publications Warehouse

    Love, J.J.; Mursula, K.; Tsai, V.C.; Perkins, D.M.

    2011-01-01

    Recent studies have led to speculation that solar-terrestrial interaction, measured by sunspot number and geomagnetic activity, has played an important role in global temperature change over the past century or so. We treat this possibility as an hypothesis for testing. We examine the statistical significance of cross-correlations between sunspot number, geomagnetic activity, and global surface temperature for the years 1868-2008, solar cycles 11-23. The data contain substantial autocorrelation and nonstationarity, properties that are incompatible with standard measures of cross-correlational significance, but which can be largely removed by averaging over solar cycles and first-difference detrending. Treated data show an expected statistically- significant correlation between sunspot number and geomagnetic activity, Pearson p < 10-4, but correlations between global temperature and sunspot number (geomagnetic activity) are not significant, p = 0.9954, (p = 0.8171). In other words, straightforward analysis does not support widely-cited suggestions that these data record a prominent role for solar-terrestrial interaction in global climate change. With respect to the sunspot-number, geomagnetic-activity, and global-temperature data, three alternative hypotheses remain difficult to reject: (1) the role of solar-terrestrial interaction in recent climate change is contained wholly in long-term trends and not in any shorter-term secular variation, or, (2) an anthropogenic signal is hiding correlation between solar-terrestrial variables and global temperature, or, (3) the null hypothesis, recent climate change has not been influenced by solar-terrestrial interaction. ?? 2011 by the American Geophysical Union.

  8. Structural and spectral studies of sunspots

    NASA Technical Reports Server (NTRS)

    Wyller, A. A.

    1973-01-01

    The work is reported in the multicolor photometry of umbral cores, and the residual intensity midway between the Na D1 and D2 lines. The photelectric magnetometer observations, the generation of umbral flashes and penumbral running waves, and the work on sunspot interior modes with Alfen wave emission are discussed.

  9. The Sunspot Record: 1826-1980

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2014-01-01

    The International Sunspot Number is used as a measure of the level of solar activity in many important studies. This includes studies of the effects of solar activity on climate change and on the generation of radioisotopes used to infer levels of solar activity going back thousands of years. Any systematic errors in the historical record of the sunspot number can profoundly alter the conclusions of these studies. There is substantial evidence that the currently accepted International Sunspot Numbers have been subjected to changes in the way the numbers are calculated and to changes in the weights given to observations of various observers. In this talk I will focus on the time period from 1826 to 1980 which covers principal observers Schwabe, Wolf, Wolfer, Brunner, and Waldmeier. Previous investigations have indicated problems associated with Schwabe's observations (1826 to 1867), the first decades of the Greenwich observations (1874 to about 1910), and the introduction of a different counting method by Waldmeier (1946-1980). I will examine the evidence for these problems and the possible solutions that might be used to provide improved estimates of the sunspot numbers and their errors over this time interval.

  10. Sunspots and Their Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Ribeiro, C. I.

    2013-01-01

    In this paper an example of a simple harmonic motion, the apparent motion of sunspots due to the Sun's rotation, is described, which can be used to teach this subject to high-school students. Using real images of the Sun, students can calculate the star's rotation period with the simple harmonic motion mathematical expression.

  11. Vortex attraction and the formation of sunspots

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1992-01-01

    A downdraft vortex ring in a stratified atmosphere exhibits universal attraction for nearby vertical magnetic flux bundles. It is speculated that the magnetic fields emerging through the surface of the sun are individually encircled by one or more subsurface vortex rings, providing an important part of the observed clustering of magnetic fibrils to form pores and sunspots.

  12. Flaring Rates and the Evolution of Sunspot Group McIntosh Classifications

    NASA Astrophysics Data System (ADS)

    McCloskey, Aoife E.; Gallagher, Peter T.; Bloomfield, D. Shaun

    2016-08-01

    Sunspot groups are the main source of solar flares, with the energy to power them being supplied by magnetic-field evolution ( e.g. flux emergence or twisting/shearing). To date, few studies have investigated the statistical relation between sunspot-group evolution and flaring, with none considering evolution in the McIntosh classification scheme. Here we present a statistical analysis of sunspot groups from Solar Cycle 22, focusing on 24-hour changes in the three McIntosh classification components. Evolution-dependent ≥ C1.0, ≥ M1.0, and ≥ X1.0 flaring rates are calculated, leading to the following results: i) flaring rates become increasingly higher for greater degrees of upward evolution through the McIntosh classes, with the opposite found for downward evolution; ii) the highest flaring rates are found for upward evolution from larger, more complex, classes ( e.g. Zurich D- and E-classes evolving upward to F-class produce ≥ C1.0 rates of 2.66± 0.28 and 2.31 ± 0.09 flares per 24 hours, respectively); iii) increasingly complex classes give higher rates for all flare magnitudes, even when sunspot groups do not evolve over 24 hours. These results support the hypothesis that injection of magnetic energy by flux emergence ( i.e. increasing in Zurich or compactness classes) leads to a higher frequency and magnitude of flaring.

  13. COMPARISON OF CHAOTIC AND FRACTAL PROPERTIES OF POLAR FACULAE WITH SUNSPOT ACTIVITY

    SciTech Connect

    Deng, L. H.; Xiang, Y. Y.; Dun, G. T.; Li, B.

    2016-01-15

    The solar magnetic activity is governed by a complex dynamo mechanism and exhibits a nonlinear dissipation behavior in nature. The chaotic and fractal properties of solar time series are of great importance to understanding the solar dynamo actions, especially with regard to the nonlinear dynamo theories. In the present work, several nonlinear analysis approaches are proposed to investigate the nonlinear dynamical behavior of the polar faculae and sunspot activity for the time interval from 1951 August to 1998 December. The following prominent results are found: (1) both the high- and the low-latitude solar activity are governed by a three-dimensional chaotic attractor, and the chaotic behavior of polar faculae is the most complex, followed by that of the sunspot areas, and then the sunspot numbers; (2) both the high- and low-latitude solar activity exhibit a high degree of persistent behavior, and their fractal nature is due to such long-range correlation; (3) the solar magnetic activity cycle is predictable in nature, but the high-accuracy prediction should only be done for short- to mid-term due to its intrinsically dynamical complexity. With the help of the Babcock–Leighton dynamo model, we suggest that the nonlinear coupling of the polar magnetic fields with strong active-region fields exhibits a complex manner, causing the statistical similarities and differences between the polar faculae and the sunspot-related indicators.

  14. Comparison of Chaotic and Fractal Properties of Polar Faculae with Sunspot Activity

    NASA Astrophysics Data System (ADS)

    Deng, L. H.; Li, B.; Xiang, Y. Y.; Dun, G. T.

    2016-01-01

    The solar magnetic activity is governed by a complex dynamo mechanism and exhibits a nonlinear dissipation behavior in nature. The chaotic and fractal properties of solar time series are of great importance to understanding the solar dynamo actions, especially with regard to the nonlinear dynamo theories. In the present work, several nonlinear analysis approaches are proposed to investigate the nonlinear dynamical behavior of the polar faculae and sunspot activity for the time interval from 1951 August to 1998 December. The following prominent results are found: (1) both the high- and the low-latitude solar activity are governed by a three-dimensional chaotic attractor, and the chaotic behavior of polar faculae is the most complex, followed by that of the sunspot areas, and then the sunspot numbers; (2) both the high- and low-latitude solar activity exhibit a high degree of persistent behavior, and their fractal nature is due to such long-range correlation; (3) the solar magnetic activity cycle is predictable in nature, but the high-accuracy prediction should only be done for short- to mid-term due to its intrinsically dynamical complexity. With the help of the Babcock-Leighton dynamo model, we suggest that the nonlinear coupling of the polar magnetic fields with strong active-region fields exhibits a complex manner, causing the statistical similarities and differences between the polar faculae and the sunspot-related indicators.

  15. Sunspots and Giant-Cell Convection

    NASA Technical Reports Server (NTRS)

    Moore, Ron L.; Hathaway, David H.; Reichmann, Ed J.

    2000-01-01

    From analysis of Doppler velocity images from SOHO/MDI, Hathaway et al (2000, Solar Phys., in press) have found clear evidence for giant convection cells that fill the solar surface, have diameters 3 - 10 times that typical of supergranules, and have lifetimes approx. greater than 10 days. Analogous to the superposition of the granular convection on the supergranular convection, the approx. 30,000 km diameter supergranules are superposed on these still larger giant cells. Because the giant cells make up the large-scale end of a continuous power spectrum that peaks at the size scale of supergranules, it appears that the giant cells are made by the same mode of convection as the supergranules. This suggests that the giant cells are similar to supergranules, just longer-lived, larger in diameter, and deeper. Here we point out that the range of lengths of large bipolar sunspot groups is similar to the size range of giant cells. This, along with the long lives (weeks) of large sunspots, suggests that large sunspots sit in long-lived, deep downflows at the corners of giant cells, and that the distance from leader to follower sunspots in large bipolar groups is the distance from one giant-cell corner to the next. By this line of reasoning, an unusually large and strong downdraft might pull in both legs of a rising spot-group magnetic flux loop, resulting in the formation of a delta sunspot. This leads us to suggest that a large, strong giant-cell corner downdraft should be present at the birthplaces of large delta sunspots for some time (days to weeks) before the birth. Thus, early detection of such downdrafts by local helioscismology might provide an early warning for the formation of those active regions (large delta sunspot groups) that produce the Sun's most violent flares and coronal mass ejections. This work is supported by NASA's Office of Space Science through the Solar Physics Branch of its Sun-Earth Connection Program.

  16. ASYMMETRIC SUNSPOT ACTIVITY AND THE SOUTHWARD DISPLACEMENT OF THE HELIOSPHERIC CURRENT SHEET

    SciTech Connect

    Wang, Y.-M.; Robbrecht, E. E-mail: eva.robbrecht@oma.be

    2011-08-01

    Observations of the interplanetary magnetic field (IMF) have suggested a statistical tendency for the heliospheric current sheet (HCS) to be shifted a few degrees southward of the heliographic equator during the period 1965-2010, particularly in the years near sunspot minimum. Using potential-field source-surface extrapolations and photospheric flux-transport simulations, we demonstrate that this southward displacement follows from Joy's law and the observed hemispheric asymmetry in the sunspot numbers, with activity being stronger in the southern (northern) hemisphere during the declining (rising) phase of cycles 20-23. The hemispheric asymmetry gives rise to an axisymmetric quadrupole field, whose equatorial zone has the sign of the leading-polarity flux in the dominant hemisphere; during the last four cycles, the polarity of the IMF around the equator thus tended to match that of the north polar field both before and after polar field reversal. However, large fluctuations are introduced by the nonaxisymmetric field components, which depend on the longitudinal distribution of sunspot activity in either hemisphere. Consistent with this model, the HCS showed an average northward displacement during cycle 19, when the 'usual' alternation was reversed and the northern hemisphere became far more active than the southern hemisphere during the declining phase of the cycle. We propose a new method for determining the north-south displacement of the HCS from coronal streamer observations.

  17. Comparative analysis of Debrecen sunspot catalogues

    NASA Astrophysics Data System (ADS)

    Győri, L.; Ludmány, A.; Baranyi, T.

    2017-02-01

    Sunspot area data are important for studying solar activity and its long-term variations. At the Debrecen Heliophysical Observatory, we compiled three sunspot catalogues: the Debrecen Photoheliographic Data (DPD), the SDO/HMI Debrecen Data (HMIDD) and the SOHO/MDI Debrecen Data. For comparison, we also compiled an additional sunspot catalogue, the Greenwich Photoheliographic Data, from the digitized Royal Greenwich Observatory images for 1974-76. By comparing these catalogues when they overlap in time, we can investigate how various factors influence the measured area of sunspots, and, in addition, we can derive area cross-calibration factors for these catalogues. The main findings are as follows. Poorer seeing increases the individual corrected spot areas and decreases the number of small spots. Interestingly, the net result of these two effects for the total corrected spot area is zero. DPD daily total corrected sunspot areas are 5 per cent smaller than the HMIDD ones. Revised DPD daily total corrected umbra areas are 9 per cent smaller than those of HMIDD. The Greenwich photoheliographic areas are only a few per cent smaller than DPD areas. A 0.2° difference between the north directions of the DPD and MDI images is found. This value is nearly the same as was found (0.22°) by us in a previous paper comparing HMI and MDI images. The area measurement practice (spots smaller than 10 mh were not directly measured but an area of 2 mh was assigned to each) of the Solar Observing Optical Network cannot explain the large area deficit of the Solar Observing Optical Network.

  18. Long-acting Injectable Risperidone Use in an 11-Years-Old Bipolar Child

    PubMed Central

    KARAKOÇ DEMİRKAYA, Sevcan; ZOROĞLU, Süleyman Salih

    2016-01-01

    Early-onset bipolar disorder is difficult for child psychiatrists in terms of both diagnosis and treatment. The proper diagnostic evaluation is negatively impacted by the atypical clinical manifestation and rapid cycling pattern of the disease, together with common comorbidity with attention-deficit hyperactivity disorder and anxiety disorder. In addition to poor insight, nonadherence to treatment, poor family coping skills, and insufficient child psychiatric inpatient units make clinicians unsuccessful in following up and treating such patients. Risperidone is a commonly used atypical antipsychotic it has been approved for the treatment of manic and mixed episodes of bipolar disorder even in 10–17-year-old patients, and it is commonly used. It has a long-acting injectable formulation. Studies on its long-acting form in younger children are limited. In this case presentation, the diagnostic procedure in an 11-year old child with bipolar disorder will be presented. Long-acting injectable risperidone use in the case of nonadherence to treatment and observed side effects will be discussed. PMID:28360814

  19. Long-acting Injectable Risperidone Use in an 11-Years-Old Bipolar Child.

    PubMed

    Karakoç Demirkaya, Sevcan; Zoroğlu, Süleyman Salih

    2016-12-01

    Early-onset bipolar disorder is difficult for child psychiatrists in terms of both diagnosis and treatment. The proper diagnostic evaluation is negatively impacted by the atypical clinical manifestation and rapid cycling pattern of the disease, together with common comorbidity with attention-deficit hyperactivity disorder and anxiety disorder. In addition to poor insight, nonadherence to treatment, poor family coping skills, and insufficient child psychiatric inpatient units make clinicians unsuccessful in following up and treating such patients. Risperidone is a commonly used atypical antipsychotic it has been approved for the treatment of manic and mixed episodes of bipolar disorder even in 10-17-year-old patients, and it is commonly used. It has a long-acting injectable formulation. Studies on its long-acting form in younger children are limited. In this case presentation, the diagnostic procedure in an 11-year old child with bipolar disorder will be presented. Long-acting injectable risperidone use in the case of nonadherence to treatment and observed side effects will be discussed.

  20. Angular Dependence of the Facular-Sunspot Coverage Relation as Derived by MDI Magnetograms

    NASA Astrophysics Data System (ADS)

    Criscuoli, S.

    2016-08-01

    Previous studies have shown that the variation over the solar magnetic activity cycle of the area of facular/network features identified from broad-band and narrow-band imagery is positively correlated with the sunspot area and number, the relation being described as either linear or quadratic. On the other hand, the temporal variation of the spatial distributions of faculae, network and sunspots follows patterns that are less obviously correlated, so that we expect the relation that describes variation of the area coverage of different types of magnetic features to vary with the position over the disk. In this work we employ Michelson Doppler Interferometer (MDI) full-disk magnetograms acquired during solar cycle 23 and at the beginning of cycle 24 to investigate the relation between the coverage of magnetic elements characterized by different amounts of magnetic flux and located at different angular distances from disk center with the sunspot number. In agreement with some previous studies we find that daily data are best described by a quadratic function while data averaged over six months are best described by a linear function. In both cases the coefficients of the fits show large dependence on the position over the disk and the magnetic flux. We also find that toward disk center six-month averaged data show asymmetries between the ascending and the descending phases. The implications for solar irradiance modeling are discussed.

  1. Towards a first detailed reconstruction of sunspot information over the last 150 years

    NASA Astrophysics Data System (ADS)

    Lefevre, Laure; Clette, Frédéric

    2013-04-01

    With four centuries of solar evolution, the International Sunspot Number (SSN) forms the longest solar time series currently available. It provides an essential reference for understanding and quantifying how the solar output has varied over decades and centuries and thus for assessing the variations of the main natural forcing on the Earth climate. For such a quantitative use, this unique time-series must be closely monitored for any possible biases and drifts. This is the main objective of the Sunspot Workshops organized jointly by the National Solar Observatory (NSO) and the Royal Observatory of Belgium (ROB) since 2010. Here, we will report about some recent outcomes of past workshops, like diagnostics of scaling errors and their proposed corrections, or the recent disagreement between the sunspot sumber and other solar indices like the 10.7cm radio flux. Our most recent analyses indicate that while part of this divergence may be due to a calibration drift in the SSN, it also results from an intrinsic change in the global magnetic parameters of sunspots and solar active regions, suggesting a possible transition to a new activity regime. Going beyond the SSN series, in the framework of the SOTERIA, TOSCA and SOLID projects, we produced a survey of all existing catalogs providing detailed sunspot information and we also located different primary solar images and drawing collections that can be exploitable to complement the existing catalogs (COMESEP project). These are first steps towards the construction of a multi-parametric time series of multiple sunspot group properties over at least the last 150 years, allowing to reconstruct and extend the current 1-D SSN series. By bringing new spatial, morphological and evolutionary information, such a data set should bring major advances for the modeling of the solar dynamo and solar irradiance. We will present here the current status of this work. The catalog now extends over the last 3 cycles (Lefevre & Clette 2011

  2. Applications of fractal geometry to dynamical evolution of sunspots

    SciTech Connect

    Milovanov, A.V.; Zelenyi, L.M. )

    1993-07-01

    A fractal model for sunspot dynamics is presented. Formation of a sunspot in the solar photosphere is considered from the viewpoint of aggregation of magnetic flux tubes on a fractal geometry. Fine structure of the magnetic flux tubes is analyzed for a broad class of non-Maxwellian plasma distribution functions. The sunspot fractal dimension is proved to depend on the parameters of the plasma distribution function, enabling one to investigate intrinsic properties of the solar plasma by means of powerful geometrical methods. Magnetic field dissipation in the tubes is shown to result in effective sunspot decay. Sunspot formation and decay times as well as the diffusion constant [ital K] deduced by using the fractal model, are in a good agreement with observational data. Disappearance of umbras in decaying sunspots is interpreted as a second-order phase transition reminiscent of the transition through the Curie point in ferromagnetics.

  3. Sunspot Numbers from ISOON: A Ten-Year Data Analysis

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Henry, T. W.

    2016-11-01

    Sunspot numbers are important tracers of historical solar activity. They are important in predicting the oncoming solar maximum, in the design of lifetimes of space assets, and in assessing the extent of solar-radiation impact on the space environment. Historically, sunspot numbers have been obtained visually from sunspot drawings. The availability of digital images from the US Air Force Improved Solar Optical Observing Network (ISOON) prototype telescope concurrent to observer-dependent sunspot numbers recorded at the National Solar Observatory (NSO) has provided a basis for comparing sunspot numbers determined from the two methods. We compare sunspot numbers from visual and digital methods observed nearly simultaneously. The advantages of digital imagery are illustrated.

  4. Sunspots During the Maunder Minimum from Machina Coelestis by Hevelius

    NASA Astrophysics Data System (ADS)

    Carrasco, V. M. S.; Álvarez, J. Villalba; Vaquero, J. M.

    2015-10-01

    We revisited the sunspot observations published by Johannes Hevelius in his book Machina Coelestis (1679) corresponding to the period of 1653 - 1675 (just in the middle of the Maunder Minimum). We show detailed translations of the original Latin texts describing the sunspot records and provide the general context of these sunspot observations. From this source, we present an estimate of the annual values of the group sunspot number based only on the records that explicitly inform us of the presence or absence of sunspots. Although we obtain very low values of the group sunspot number, in accordance with a grand minimum of solar activity, these values are significantly higher in general than the values provided by Hoyt and Schatten ( Solar Phys. 179, 189, 1998) for the same period.

  5. Observing Sunspots with 18th Century Optics

    NASA Astrophysics Data System (ADS)

    Svalgaard, Leif

    2016-05-01

    The sunspot and group numbers in the 18th Century relies heavily on the observations by J.C. Staudauch during 1749-1799 performed with a three-foot 'sky tube', likely affected by spherical and chromatc aberration. An observing network has been set up to make drawings of the spots on the solar disk using original telescopes from the 18th Century or reconstructed 'sky tubes' with the same defects as the instruments available to and affordable for amateurs of the period. We report the initial results of the effort, finding that the counts of groups and the sunspot numbers must be multipled by three to reproduce modern observations. This confirms the scale factors derived from recent revisions of the solar record.

  6. Pre-flare dynamics of sunspot groups

    SciTech Connect

    Korsós, M. B.; Baranyi, T.; Ludmány, A. E-mail: baranyi.tunde@csfk.mta.hu

    2014-07-10

    Several papers provide evidence that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare-producing areas, this work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms and follows the behavior of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalog. The most promising pre-flare signatures are the following properties of gradient variation: (1) steep increase, (2) high maximum, (3) significant fluctuation, and (4) a gradual decrease between the maximum and the flare onset that can be related to the 'pull mode' of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the following 8-10 hr.

  7. Energy Transport Below Sunspots and Faculae

    NASA Technical Reports Server (NTRS)

    Schatten, Kenneth H.; Mayr, Hans G.

    1990-01-01

    Sunspots and faculae were modeled using a modified stellar envelope code. Downflow velocities of 50 m/sec can achieve a 1,000 K drop in the surface temperature of the photosphere and reduce the surface irradiance to half its value. Concurrently, a 600 km Wilson depression forms that is associated with the enhanced density of the cooler gases. Similar upflow velocities provide for slightly enhanced temperatures and 150 km uplifted surfaces for faculae. The calculations show that, to first approximation, sunspot and facular structures (in density, temperature and pressure) can be obtained by simply vertically shifting the undisturbed photospheric materials to form wells and hillock geometries, respectively. However, the chromospheric manifestations of these features can be quite different owing to the influence of the magnetic field and flow.

  8. Chromospheric activity in sunspot light bridges

    NASA Astrophysics Data System (ADS)

    Louis, R. E.

    2016-11-01

    High-resolution filtergrams from Hinode were used to analyse the nature of chromospheric activity over a set of five sunspot light bridges. The broad-band Ca II H filtergrams depict a variety of phenomena which include large arc-shaped brightenings, bright patches, and small-scale jets. These strong brightenings are recurrent over a duration of several hours and appear to be a common attribute of a sunspot light bridge, independent of its photospheric morphology and horizontal flow pattern. Hinode spectro-polarimetric observations were used to construct far wing magnetograms from the Fe I line at 630.25 nm, which reveal the presence of small-scale magnetic and velocity inhomogeneities in the photosphere of the light bridges. Although there is strong evidence for a causal relation between the photospheric anomalies and the observed chromospheric activity, the physical mechanism responsible for the latter remains speculative.

  9. On the dissolution of sunspot groups

    NASA Technical Reports Server (NTRS)

    Wallenhorst, S. G.; Howard, R.

    1982-01-01

    The behavior of magnetic fluxes from active regions is investigated for times near sunspot disappearance. It is found that the magnetic fluxes decrease on or near the date the spot vanishes. This effect is investigated and it is concluded that it is actually due to changes in the field, rather than through dissipation of the active region fields. This is important in considerations of the large-scale behavior of solar magnetic fields.

  10. Flare differentially rotates sunspot on Sun's surface

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S.; Gary, Dale E.; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-10-01

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ~50° h-1) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena.

  11. Superpenumbral fibrils powered by sunspot oscillations

    SciTech Connect

    Chae, Jongchul; Yang, Heesu; Park, Hyungmin; Maurya, Ram Ajor; Cho, Kyung-Suk; Yurchysyn, Vasyl

    2014-07-10

    It is still a mystery how the solar chromosphere can stand high above the photosphere. The dominant portion of this layer must be dynamically supported, as is evident by the common occurrence of jets such as spicules and mottles in quiet regions, and fibrils and surges in active regions. Hence, revealing the driving mechanism of these chromospheric jets is crucial for our understanding of how the chromosphere itself exists. Here, we report our observational finding that fibrils in the superpenumbra of a sunspot are powered by sunspot oscillations. We find patterns of outward propagation that apparently originate from inside the sunspot, propagate like running penumbral waves, and develop into the fibrils. Redshift ridges seen in the time-distance plots of velocity often merge, forming a fork-like pattern. The predominant period of these shock waves increases, often jumping with distance, from 3 minutes to 10 minutes. This short-to-long period transition seems to result from the selective suppression of shocks by the falling material of their preceding shocks. Based on our results, we propose that the fibrils are driven by slow shock waves with long periods that are produced by the merging of shock waves with shorter periods propagating along the magnetic canopy.

  12. Flare differentially rotates sunspot on Sun's surface.

    PubMed

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S; Gary, Dale E; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-10-10

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ∼50° h(-1)) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena.

  13. Flare differentially rotates sunspot on Sun's surface

    PubMed Central

    Liu, Chang; Xu, Yan; Cao, Wenda; Deng, Na; Lee, Jeongwoo; Hudson, Hugh S.; Gary, Dale E.; Wang, Jiasheng; Jing, Ju; Wang, Haimin

    2016-01-01

    Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of the dense photosphere involving bulk motion. Here we report the sudden flare-induced rotation of a sunspot using the unprecedented spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by magnetic data from the Solar Dynamics Observatory. It is clearly observed that the rotation is non-uniform over the sunspot: as the flare ribbon sweeps across, its different portions accelerate (up to ∼50° h−1) at different times corresponding to peaks of flare hard X-ray emission. The rotation may be driven by the surface Lorentz-force change due to the back reaction of coronal magnetic restructuring and is accompanied by a downward Poynting flux. These results have direct consequences for our understanding of energy and momentum transportation in the flare-related phenomena. PMID:27721463

  14. An Investigation into Understanding of Geological Time among 10- and 11-Year-Old Children.

    ERIC Educational Resources Information Center

    Trend, Roger

    1998-01-01

    Focuses on the understanding of British children (N=189) of geologic time as they participate in related activities. Indicates that 10- and 11-year-old children lack a clear chronology of geologic events. Contains 22 references. (DDR)

  15. Major revision of sunspot number: implication for the ionosphere models

    NASA Astrophysics Data System (ADS)

    Gulyaeva, Tamara

    2016-07-01

    Recently on 1st July, 2015, a major revision of the historical sunspot number series has been carried out as discussed in [Clette et al., Revisiting the Sunspot Number. A 400-Year Perspective on the Solar Cycle, Space Science Reviews, 186, Issue 1-4, pp. 35-103, 2014). The revised SSN2.0 dataset is provided along with the former SSN1.0 data at http://sidc.oma.be/silso/. The SSN2.0 values exceed the former conventional SSN1.0 data so that new SSNs are greater in many cases than the solar radio flux F10.7 values which pose a problem of SSN2.0 implementation as a driver of the International Reference Ionosphere, IRI, its extension to plasmasphere, IRI-Plas, NeQuick model, Russian Standard Ionosphere, SMI. In particular, the monthly predictions of the F2 layer peak are based on input of the ITU-R (former CCIR) and URSI maps. The CCIR and URSI maps coefficients are available for each month of the year, and for two levels of solar activity: low (SSN = 0) and high (SSN = 100). SSN is the monthly smoothed sunspot number from the SSN1.0 data set used as an index of the level of solar activity. For every SSN different from 0 or 100 the critical frequency foF2 and the M3000F2 radio propagation factor used for the peak height hmF2 production may be evaluated by an interpolation. The ionospheric proxies of the solar activity IG12 index or Global Electron Content GEC12 index, driving the ionospheric models, are also calibrated with the former SSN1.0 data. The paper presents a solar proxy intended to calibrate SSN2.0 data set to fit F10.7 solar radio flux and/or SSN1.0 data series. This study is partly supported by TUBITAK EEEAG 115E915.

  16. Effects of the scatter in sunspot group tilt angles on the large-scale magnetic field at the solar surface

    SciTech Connect

    Jiang, J.; Cameron, R. H.; Schüssler, M.

    2014-08-10

    The tilt angles of sunspot groups represent the poloidal field source in Babcock-Leighton-type models of the solar dynamo and are crucial for the build-up and reversals of the polar fields in surface flux transport (SFT) simulations. The evolution of the polar field is a consequence of Hale's polarity rules, together with the tilt angle distribution which has a systematic component (Joy's law) and a random component (tilt-angle scatter). We determine the scatter using the observed tilt angle data and study the effects of this scatter on the evolution of the solar surface field using SFT simulations with flux input based upon the recorded sunspot groups. The tilt angle scatter is described in our simulations by a random component according to the observed distributions for different ranges of sunspot group size (total umbral area). By performing simulations with a number of different realizations of the scatter we study the effect of the tilt angle scatter on the global magnetic field, especially on the evolution of the axial dipole moment. The average axial dipole moment at the end of cycle 17 (a medium-amplitude cycle) from our simulations was 2.73 G. The tilt angle scatter leads to an uncertainty of 0.78 G (standard deviation). We also considered cycle 14 (a weak cycle) and cycle 19 (a strong cycle) and show that the standard deviation of the axial dipole moment is similar for all three cycles. The uncertainty mainly results from the big sunspot groups which emerge near the equator. In the framework of Babcock-Leighton dynamo models, the tilt angle scatter therefore constitutes a significant random factor in the cycle-to-cycle amplitude variability, which strongly limits the predictability of solar activity.

  17. Joy's law and its features according to the data of three sunspot catalogs

    NASA Astrophysics Data System (ADS)

    Ivanov, V. G.

    2012-12-01

    This paper investigates the trend towards an increase in the tilt of sunspot groups with increasing latitude (Joy's law) and the relationship between the features of this law and solar activity parameters. In addition to the known data of the Mount Wilson and Kodaikanal observatories, the analysis uses the Pulkovo database of solar activity, which allows for the estimation of the reliability of the conclusions obtained by other authors from the first two catalogs. It is shown that Joy's law is manifested in all three data series and has many features in common. In particular at latitudes above 25-30°, the tilt of sunspot groups is not linearly dependent on latitude and displays a slight decrease. However, some features of this law found previously in the data of the first two observatories (e.g., a decrease in its strength with an increase in the strength of the solar cycle) are not confirmed by our analysis.

  18. Tracking the Magnetic Flux in and around Sunspots

    NASA Astrophysics Data System (ADS)

    Sheeley, N. R., Jr.; Stauffer, J. R.; Thomassie, J. C.; Warren, H. P.

    2017-02-01

    We have developed a procedure for tracking sunspots observed by the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory and for making curvature-corrected space/time maps of the associated line-of-sight magnetic field and continuum intensity. We apply this procedure to 36 sunspots, each observed continuously for nine days around its central meridian passage time, and find that the proper motions separate into two distinct components depending on their speeds. Fast (∼3–5 km s‑1) motions, comparable to Evershed flows, are produced by weak vertical fluctuations of the horizontal canopy field and recur on a timescale of 12–20 min. Slow (∼0.3–0.5 km s‑1) motions diverge from a sunspot-centered ring whose location depends on the size of the sunspot, occurring in the mid-penumbra for large sunspots and at the outer edge of the penumbra for small sunspots. The slow ingoing features are contracting spokes of a quasi-vertical field of umbral polarity. These inflows disappear when the sunspot loses its penumbra, and may be related to inward-moving penumbral grain. The slow outgoing features may have either polarity depending on whether they originate from quasi-vertical fields of umbral polarity or from the outer edge of the canopy. When a sunspot decays, the penumbra and canopy disappear, and the moat becomes filled with slow outflows of umbral polarity. We apply our procedure to decaying sunspots, to long-lived sunspots, and to numerical simulations of a long-lived sunspot by Rempel.

  19. 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.

  20. Shuttle program. Solar activity prediction of sunspot numbers, predicted solar radio flux

    NASA Technical Reports Server (NTRS)

    Johnson, G. G.; Newman, S. R.

    1980-01-01

    A solar activity prediction technique for monthly mean sunspot numbers over a period of approximately ten years from February 1979 to January 1989 is presented. This includes the predicted maximum epoch of solar cycle 21, approximately January 1980, and the predicted minimum epoch of solar cycle 22, approximately March 1987. Additionally, the solar radio flux 10.7 centimeter smooth values are included for the same time frame using a smooth 13 month empirical relationship. The incentive for predicting solar activity values is the requirement of solar flux data as input to upper atmosphere density models utilized in mission planning satellite orbital lifetime studies.

  1. Sunspot magnetic structure and interspot radio source formation

    NASA Astrophysics Data System (ADS)

    Solov'ev, A. A.

    2015-12-01

    The magnetic structure of a typical sunspot is represented as a set of three interacting magnetic fluxes. The first one, F1, escapes upward from the sunspot umbra and closes through the corona on the sunspot of opposite polarity. The second, F2, forms the sunspot penumbra. It includes Evershed flows emerging from the sunspot, the heavy photospheric plasma of which cannot be pulled up to the corona. For this reason, the F2 flux at the outer edge of the penumbra should close on the photosphere adjacent to the sunspot, i.e., here the F2 field changes sign. The third flux, F3, is the external magnetic field flux and has the same polarity as F1. Thus, magnetic fields of different signs occur near the outer boundary of the sunspot penumbra. Magnetic reconnections will inevitably take place there. Smalland multiscale current sheets in which particles are accelerated are formed. The latter fill short and low magnetic loops that connect sunspots of different polarity in the bipolar group and form interspot radio sources at the tops of these loops.

  2. 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.

  3. On the level of skill in predicting maximum sunspot number - A comparative study of single variate and bivariate precursor techniques

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1990-01-01

    The level of skill in predicting the size of the sunspot cycle is investigated for the two types of precursor techniques, single variate and bivariate fits, both applied to cycle 22. The present level of growth in solar activity is compared to the mean level of growth (cycles 10-21) and to the predictions based on the precursor techniques. It is shown that, for cycle 22, both single variate methods (based on geomagnetic data) and bivariate methods suggest a maximum amplitude smaller than that observed for cycle 19, and possibly for cycle 21. Compared to the mean cycle, cycle 22 is presently behaving as if it were a +2.6 sigma cycle (maximum amplitude of about 225), which means that either it will be the first cycle not to be reliably predicted by the combined precursor techniques or its deviation relative to the mean cycle will substantially decrease over the next 18 months.

  4. SHORT DYNAMIC FIBRILS IN SUNSPOT CHROMOSPHERES

    SciTech Connect

    Rouppe van der Voort, L.; De la Cruz Rodríguez, J.

    2013-10-10

    Sunspot chromospheres display vigorous oscillatory signatures when observed using chromospheric diagnostics such as the strong Ca II lines and Hα. New high-resolution sunspot observations from the Swedish 1 m Solar Telescope show the ubiquitous presence of small-scale, periodic, jet-like features that move up and down. This phenomenon has not been described before. The typical width of these features is about 0.''3 and they display clear parabolic trajectories in space-time diagrams. The maximum extension of the top of the jets is lowest in the umbra, a few 100 km, and progressively longer further away from the umbra in the penumbra, with the longest extending more than 1000 km. These jets resemble the dynamic fibrils found in plage regions but at smaller extensions. Local thermodynamic equilibrium inversion of spectropolarimetric Ca II 8542 observations enabled a comparison of the magnetic field inclination and properties of these short jets. We find that the most extended of these jets also have longer periods and tend to be located in regions with more horizontal magnetic fields. These results are direct observational confirmation of the mechanism of long-period waves propagating along inclined magnetic fields into the solar chromosphere. This mechanism was identified earlier as the driver of dynamic fibrils in plage, part of the mottles in the quiet Sun, and the type I spicules at the limb. The sunspot dynamic fibrils that we report here represent a new class of manifestation of this mechanism, distinct from the transient penumbral and umbral micro-jets reported earlier.

  5. Infrared array measurements of sunspot magnetic fields

    NASA Astrophysics Data System (ADS)

    McPherson, M. R.; Lin, H.; Kuhn, J. R.

    1992-06-01

    A 128 x 128 format HgCdTl IR array has been used with the Sacramento Peak Observatory Vacuum Telescope (VTT) and echelle spectrograph to obtain two-dimensional observations of the true magnetic field strength in a sunspot. All of the spectral information contained in the unpolarized IR Fraunhofer line profile, with time resolution of about a minute is retained. Unlike previous optical observations (cf. Adam, 1990), observations readily allow direct field strength measurements out to the outer edge of the penumbra. The magnetic flux density in the outer penumbra is not well described by an extrapolation of the quadratic polynomial, in normalized central distance, that describes the umbral field.

  6. Correction of sunspot intensities for scattered light

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1973-01-01

    Correction of sunspot intensities for scattered light usually involves fitting theoretical curves to observed aureoles (Zwaan, 1965; Staveland, 1970, 1972). In this paper we examine the inaccuracies in the determination of scattered light by this method. Earlier analyses are extended to examine uncertainties due to the choice of the expression for limb darkening. For the spread function, we consider Lorentzians and Gaussians for which analytic expressions for the aureole can be written down. Lorentzians lead to divergence and normalization difficulties, and should not be used in scattered light determinations. Gaussian functions are more suitable.

  7. Mff-Analysis of Zurich Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Nefedyev, Yuri; Panischev, Oleg; Demin, Sergey

    2016-07-01

    In this paper we consider the dynamic and stochastic properties of the solar activity by using the Memory Function Formalism (MFF) to analyze the Zurich sunspot numbers. This approach allows to study the statistical memory effects and dynamic alteration in the considered dynamics. The phase portraits are the simple graphical method to analyze the dynamic properties of solar activity. Power spectra of the memory functions allow to reveal the frequency characteristics of the solar activity in different relaxation levels. The non-Markovian parameter describes the memory effects in considered dynamics. Work was supported by grants RFBR 15-02-01638-a and 16-02-00496-a.

  8. Radial profile of sunspot magnetic field on the SDO data

    NASA Astrophysics Data System (ADS)

    Zhivanovich, I.; Solov'ev, A. A.; Smirnova, V. V.; Riehokainen, A.; Nagnibeda, V. G.

    2016-03-01

    The spatial distribution of the vertical (with respect to the surface photosphere) magnetic field in a sunspot plays an important role in modeling the temperature-density characteristics of sunspot, in the calculation of its total energy, in the study of magnetic field oscillations of sunspots and in many others tasks. A number of radial field distributions, such as the Broxon's formula, is discussed in the literature, but the generally accepted, "canonical" profile of the vertical field in a sunspot does not exist on today. Magnetograms obtained with the HMI device of the Solar Dynamic Observatory (Scherrer et al. in Sol. Phys. 275(1-2):207-227, 2012), due to their high spatial resolution, provide a good opportunity to get closer to solving this problem. We have studied 30 regular round-shaped unipolar sunspots, situated near the center of the solar disk, without any changes of their configuration or the magnetic field strength during a day or two. Four radial cuts were taken on the magnetograms for each of these 30 sunspots. The magnetic field strength measured along a cut was normalized to the maximum value of the field in the sunspot, all distances are measured in units of the radius of the umbra of the sunspot. It is shown that the radial profile of the vertical field averaged over all studied sunspots has a smooth bell-shaped form and can be well described by the analytic formula for a magnetic monopole, with the depth of immersion into the convective zone of the Sun close to the radius of the sunspot umbra.

  9. North-south excess of hemispheric sunspot numbers and cosmic ray asymmetric solar modulation

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2015-12-01

    Timeline of solar activity is reviewed for 1945-2013 with data for yearly north-south excess (NSE) of hemispheric sunspot numbers (SSNs) for six cycles (18-23) and rising phase of cycle 24. There are more sunspots in north hemisphere for 1950-1970 (cycles 18-20) and excess in south hemisphere for 1980-2010 (cycles 21-23). To the best of our knowledge, the physical cause(es) for NSE and change of its sign are not known, highlighting the fact that we do not yet understand how the solar Dynamo works. Others have analyzed NSE data for shorter periods. We study the relationship between NSE and galactic cosmic ray (GCR) asymmetric solar modulation for the space age with high latitude neutron monitor data located in USA and Europe; space age began in October 1963 with in situ measurements of the solar wind parameters at 1 AU. We infer an asymmetric GCR particle density gradient normal to the ecliptic plane exists for 1963-2013 and undergoes significant temporal variations unrelated to Schwabe or Hale cycle. Furthermore, it has no physical relationship with NSE for the period of our analysis, contrary to the result of a prior study for a shorter period.

  10. 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

  11. Sunspot activity and cosmic ray modulation at 1 a.u. for 1900-2013

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2014-10-01

    The descent of sunspot cycle 23 to an unprecedented minimum of long duration in 2006-2009 led to a prolonged galactic cosmic ray (GCR) recovery to the highest level observed in the instrumental era for a variety of energetic charged particle species on Earth, over a wide range of rigidities. The remarkable GCR increase measured by several ground-based, balloon-borne, and detectors on a satellite is described and discussed. It is accompanied by a decrease in solar wind velocity and interplanetary magnetic field at 1 a.u., reaching the lowest values since measurements of the solar wind began in October 1963; the solar polar field strength (μT) measured at the Wilcox Solar Observatory (WSO) is also significantly reduced compared to prior cycles since the start of the program in 1976, the polar field in the northern hemisphere reversed in June 2012 and again in February 2014, that in the southern hemisphere reversed in July 2013. If updates of WSO data confirm the second reversal in northern solar hemisphere, it would pose a serious challenge to the Dynamo Theory. The long-term change in solar behavior may have begun in 1992, perhaps earlier. The physical underpinnings of these solar changes need to be understood and their effect on GCR modulation processes clarified. The study discusses the recent phenomena in the context of GCR modulation since 1900. These happenings affected our empirical predictions for the key parameters for the next two sunspot cycles (they may be progressively less active than sunspot cycle 24) but it enhanced support for our prediction that solar activity is descending into a Dalton-like grand minimum in the middle of the twentyfirst century, reducing the frequency of the coronal mass ejections; they determine the space weather affecting the quality of life on Earth, radiation dose for hardware and human activities in space as well as the frequency of large Forbush decreases at 1 a.u.

  12. Microwave emission above steady and moving sunspots

    NASA Technical Reports Server (NTRS)

    Drago, F. Chiuderi; Alissandrakis, C.; Hagyard, M.

    1987-01-01

    Two-dimensional maps of radio brightness temperature and polarization, computed assuming thermal emission with free-free and gyroresonance absorption, are compared with observations of active region 2502, performed at Westerbork at lambda = 6.16 cm during a period of 3 days in June 1980. The computation is done assuming a homogeneous model in the whole field of view and a force-free extrapolation of the photospheric magnetic field observed at MSFC with a resolution of 2.34 arcsec. The mean results are the following: (1) a very good agreement is found above the large leading sunspot of the group, assuming a potential extrapolation of the magnetic field and a constant conductive flux in the transition region ranging from .2 x 10 to the 6th to 10 to the 7th erg/sq cm 5; (2) a strong radio source, associated with a new-born moving sunspot, cannot be ascribed to thermal emission. It is suggested that this source may be due to synchrotron radiation by mildly relativistic electrons accelerated by resistive instabilities occurring in the evolving magnetic configuration. An order-of-magnitude computation of the expected number of accelerated particles seems to confirm this hypothesis.

  13. Theoretical Models of Sunspot Structure and Dynamics

    NASA Astrophysics Data System (ADS)

    Thomas, J. H.

    Recent progress in theoretical modeling of a sunspot is reviewed. The observed properties of umbral dots are well reproduced by realistic simulations of magnetoconvection in a vertical, monolithic magnetic field. To understand the penumbra, it is useful to distinguish between the inner penumbra, dominated by bright filaments containing slender dark cores, and the outer penumbra, made up of dark and bright filaments of comparable width with corresponding magnetic fields differing in inclination by some 30° and strong Evershed flows in the dark filaments along nearly horizontal or downward-plunging magnetic fields. The role of magnetic flux pumping in submerging magnetic flux in the outer penumbra is examined through numerical experiments, and different geometric models of the penumbral magnetic field are discussed in the light of high-resolution observations. Recent, realistic numerical MHD simulations of an entire sunspot have succeeded in reproducing the salient features of the convective pattern in the umbra and the inner penumbra. The siphon-flow mechanism still provides the best explanation of the Evershed flow, particularly in the outer penumbra where it often consists of cool, supersonic downflows.

  14. Microwave emission from steady and moving sunspots

    NASA Technical Reports Server (NTRS)

    Alissandrakis, C. E.; Chiuderi Drago, F.; Hagyard, M. J.

    1987-01-01

    Force-free extrapolations of photospheric magnetic field observations from Marshall Space Flight Center have been used to compute the total intensity and circular polarizaton of sunspot associated emission from active region 2502 in the period June 13 to 15, 1980. The computed maps were compared to high resolution observations of the same active region obtained with the Westerbork Synthesis Radio Telescope. The most interesting aspect of the active region was the development of a new spot between the preceding and the following spots on June 14, which subsequently merged with the preceding with the preceding spot. The new spot was associated with enhanced microwave emission with a peak brightness temperature in excess of 4 x 10 to the 6th K. It is shown that unrealistic values of the conductive flux are required for the interpretation of the emission of the new sunspot in terms of thermal processes. It is suggested that this source is due to gyrosynchrotron radiation from mildly relativistic electrons accelerated by resistive instabilities in the evolving magnetic field.

  15. A Decade of Diminishing Sunspot Vigor

    NASA Astrophysics Data System (ADS)

    Livingston, W. C.; Penn, M.; Svalgard, L.

    2011-05-01

    1A Decade of Diminishing Sunspot Vigor William Livingston1 Matt Penn1 Leif Svalgard2 Sunspots are small dark areas on the solar disk where internal magnetism, 1500 to 3500 Gauss, has been buoyed to the surface. (Spot life times are the order of one day to a couple of weeks or more. They are thought to be dark because convection inhibits the outward transport of energy there). Their "vigor” can be described by spot area, spot brightness intensity, and magnetic field. From 2001 to 2011 we have measured field strength and brightness at the darkest position in umbrae of 1750 spots using the Zeeman splitting of the Fe 1564.8 nm line. Only one observation per spot per day is carried out during our monthly telescope time of 3-4 days average. Over this interval the temporal mean magnetic field has declined about 500 Gauss and mean spot intensity has risen about 20%. We do not understand the physical mechanism behind these changes or the effect, if any, it will have on the Earth environment. 1. wcl@noao.edu mpenn@noao.edu 2. leif@leif.org

  16. Observations of dynamical phenomena in sunspots

    NASA Technical Reports Server (NTRS)

    Nye, A. H.; Cram, L. E.; Beckers, J. M.; Thomas, J. H.

    1981-01-01

    A preliminary report of the results of one observing run based on data from one spectral line, the photospheric magnetic line Fe 6303, is presented as part of a series of observations of dynamical phenomena in sunspots using photographic spectra with the SPO vacuum tower telescope and echelle spectrograph. The ejection of a magnetic feature from the outer edge of the penumbra was observed. The initial total field strength of the feature was about 1000 gauss, which appeared to decrease as the feature moved away from the sunspot. The proper motion was about 2 km/s, and the velocity field measured in the V profile showed a downflow of 400 m/s on the spotward side of the moving magnetic feature. Umbral oscillations at the photospheric level with a herringbone structure characteristic of horizontally propagating waves, suggesting some overtone mode of membrane oscillation in the umbra, were seen. The peak amplitude of the oscillation was about 200 m/s, and the mean power spectrum had several clear peaks.

  17. Mass and energy flow near sunspots

    NASA Technical Reports Server (NTRS)

    Nye, Alan; Bruning, David; Labonte, Barry J.

    1988-01-01

    Sunspots block the flow of energy to the solar surface. The blocked energy heats the volume beneath the spot, producing a pressure excess which drives an outflow of mass. Linear numerical models of the mass and energy flow around spots were constructed to estimate the predictions of this physical picture against the observed properties of sunspot bright rings and moat flows. The width of the bright ring and moat are predicted to be proportional to the depth of the spot penumbra, in conflict with the observed proportionality of the moat width to the spot diameter. Postulating that spot depths are proportional to spot diameters would bury the moat flow too deeply to be observed, because the radial velocity at the surface is found to be inversely proportional to the depth of the spot penumbra. The radial velocity at the surface is of order a few hundred meters per second after 1 day, in agreement with the observed excess of moat velocities over supergranule velocities.

  18. Psychiatric Disorders in Extremely Preterm Children: Longitudinal Finding at Age 11 Years in the EPICure Study

    ERIC Educational Resources Information Center

    Johnson, Samantha; Hollis, Chris; Kochhar, Puja; Hennessy, Enid; Wolke, Dieter; Marlow, Neil

    2010-01-01

    Objective: To investigate the prevalence and risk factors for psychiatric disorders in extremely preterm children. Method: All babies born less than 26 weeks gestation in the United Kingdom and Ireland from March through December 1995 were recruited to the EPICure Study. Of 307 survivors at 11 years of age, 219 (71%) were assessed alongside 153…

  19. Duration, Distance, and Speed Judgments of Two Moving Objects by 4- to 11-Year-Olds.

    ERIC Educational Resources Information Center

    Matsuda, Fumiko

    1996-01-01

    Four- to 11-year-olds made duration, distance, and speed judgments on Piagetian tasks where cars ran on parallel tracks. Among younger children, duration and distance judgments had approximately the same difficulty. Among older children, distance judgments were easier than duration judgments, and symmetry of effects of temporal and spatial…

  20. Easy Growth Experiment on Peas Stimulates Interest in Biology for 10-11 Year Old Pupils

    ERIC Educational Resources Information Center

    McEwen, Birgitta

    2007-01-01

    How do we support the enthusiasm children show for biology in school? Unfortunately, lack of exciting practical work and boring biology lessons seem to make science less popular. As a senior lecturer in plant physiology at Karlstad University I have simplified experiments intended for students at university and then tested them on 10-11 year old…

  1. Swift J1753.5-0127 is heading to quiescence after an 11-year outburst

    NASA Astrophysics Data System (ADS)

    Russell, David M.; AlMannaei, Aisha; Qasim, Ahlam Al; Shaw, A. W.; Charles, P. A.; Lewis, Fraser

    2016-11-01

    The black hole candidate X-ray binary Swift J1753.5-0127 began an outburst in June 2005 (ATel #546). After an initial outburst peak, the source settled into a hard state, and was persistent for the next 11 years.

  2. Korean 4- to 11-Year-Old Student Conceptions of Heat and Temperature

    ERIC Educational Resources Information Center

    Paik, Seoung-Hey; Cho, Boo-Kyung; Go, Young-Mi

    2007-01-01

    The aim of the present study is to shed light on the conceptions that young students have of heat and temperature, concepts that are both important in school science curricula and closely related to daily life. The subjects of the study were students from a rural district in South Korea and they ranged in age from 4 to 11 years. Interviews were…

  3. Basic Facts about Low-Income Children: Children 6 through 11 Years, 2013. Fact Sheet

    ERIC Educational Resources Information Center

    Jiang, Yang; Ekono, Mercedes; Skinner, Curtis

    2015-01-01

    Children under 18 years represent 23 percent of the population, but they comprise 33 percent of all people in poverty. Among all children, 44 percent live in low-income families and approximately one in every five (22 percent) live in poor families. Similarly, among children in middle childhood (age 6 through 11 years), 45 percent live in…

  4. Developing Number Knowledge: Assessment, Teaching and Intervention with 7-11 Year Olds. Math Recovery

    ERIC Educational Resources Information Center

    Wright, Robert J.; Ellemor-Collins, David; Tabor, Pamela D.

    2011-01-01

    This fourth book in the Mathematics Recovery series equips teachers with detailed pedagogical knowledge and resources for teaching number to 7 to 11-year olds. Drawing on extensive programs of research, curriculum development, and teacher development, the book offers a coherent, up-to-date approach emphasizing computational fluency and the…

  5. Race and Ethnicity: An 11-Year Content Analysis of "Counseling and Values"

    ERIC Educational Resources Information Center

    Baker, Caroline A.; Bowen, Nikol V.; Butler, J. Yasmine; Shavers, Marjorie C.

    2013-01-01

    Using the Dimensions of Personal Identity Model proposed by Arredondo and Glauner (as cited in Arredondo et al., 1996), the authors reviewed the last 11 years of the Association for Spiritual, Ethical, and Religious Values in Counseling's journal, "Counseling and Values", specifically regarding the "A" dimensions of race and ethnicity. Twenty-five…

  6. Position of the American Dietetic Association: Nutrition Guidance for Health Children Ages 2 to 11 Years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is the position of the American Dietetic Association that children ages 2 to 11 years should achieve optimal physical and cognitive development, attain a healthy weight, enjoy food, and reduce the risk of chronic disease through appropriate eating habits and participation in regular physical acti...

  7. Merging two data sets of hemispheric Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Rybák, J.; Bendík, P.; Temmer, M.; Veronig, A.; Hanslmeier, A.

    First results on merging two data sets of hemispheric sunspot numbers -- from the Kanzelhöhe Solar Observatory and the Skalnaté Pleso Observatory -- for the time span 1977 -- 1978 are presented. A total coverage of 86% was reached for the merged data set. In order to have a homogeneous time series, the daily sunspot numbers for the full disk from both observing stations were normalized to the international relative sunspot number of the day. The derived hemispheric sunspot numbers from Kanzelhöhe and Skalnaté Pleso Observatory %compared for 290 common observing show very high correlations (r ≳ 0.95), and the estimated data noise yields significant differences only for small values of sunspot numbers. These outcomes demonstrate the high potential of the applied merging procedure, and are the basis for an ongoing project to derive hemispheric sunspot numbers back to the year 1945 using sunspot drawings from Kanzelhöhe and Skalnaté Pleso Observatory.

  8. Two populations of sunspots and secular variations of their characteristics

    NASA Astrophysics Data System (ADS)

    Nagovitsyn, Yu. A.; Pevtsov, A. A.; Osipova, A. A.; Tlatov, A. G.; Miletskii, E. V.; Nagovitsyna, E. Yu.

    2016-10-01

    We investigate the magnetic fields and total areas of mid- and low-latitude sunspots based on observations at the Greenwich and Kislovodsk (sunspot areas) and Mount Wilson, Crimean, Pulkovo, Ural, IMIS, Ussuriysk, IZMIRAN, and Shemakha (magnetic fields) observatories. We show that the coefficients in the linear form of the dependence of the logarithm of the total sunspot area S on its maximum magnetic field H change with time. Two distinct populations of sunspots are identified using the twodimensional H-log S occurrence histogram: small and large, separated by the boundaries log S = 1.6 ( S = 40 MSH) and H = 2050 G. Analysis of the sunspot magnetic flux also reveals the existence of two lognormally distributed populations with the mean boundary between them Φ = 1021 Mx. At the same time, the positions of the flux occurrence maxima for the populations change on a secular time scale: by factors of 4.5 and 1.15 for small and large sunspots, respectively. We have confirmed that the sunspots form two physically distinct populations and show that the properties of these populations change noticeably with time. This finding is consistent with the hypothesis about the existence of two magnetic field generation zones on the Sun within the framework of a spatially distributed dynamo.

  9. On the maintenance of sunspots - An ion hurricane mechanism

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Mayr, H. G.

    1985-01-01

    Inward and downflow motions below the photosphere are considered to be a means of cooling and powering sunspot dynamics. Parker's superadiabatic effect is examined with attention focused on the energetics involved in ionization advection. The current analysis enhances Parker's mechanism by allowing for a 2 m/s downflow velocity at 2000 km depth to significantly reduce the photospheric irradiance to near umbral intensities. Similarities between sunspots and terrestrial hurricanes are noted, and it was found that ionization energy plays the same role in sunspots as latent energy plays in terrestrial weather systems. Based on the hypothesis that magnetic fields are important in organizing the motions on the sun, some understanding is provided of: (1) the instability which drives the cooling mechanism for sunspots, (2) the low latitude appearance of sunspots, (3) active region development with faculae following sunspot growth, (4) the role of the fluid in maintaining the magnetic field and the role of the field as a focal point for the fluid downflow, (5) the heating mechanism and structure of faculae, (6) energy balance in active regions, and (7) the behavior difference of pores and ephemeral active regions in relation to ordinary sunspots and active regions.

  10. Systematic Regularity of Hemispheric Sunspot Areas Over the Past 140 Years

    NASA Astrophysics Data System (ADS)

    Deng, L. H.; Xiang, Y. Y.; Qu, Z. N.; An, J. M.

    2016-03-01

    Solar magnetic activity varies with time in the two hemispheres in different ways. The hemispheric interconnection of solar activity phenomena provides an important clue to understanding the dynamical behavior of solar dynamo actions. In this paper, several analysis approaches are proposed to analyze the systematic regularity of hemispheric asynchronism and amplitude asymmetry of long-term sunspot areas during solar cycles 9-24. It is found that, (1) both the hemispheric asynchronism and the amplitude asymmetry of sunspot areas are prevalent behaviors and are not anomalous, but the hemispheric asynchronism exhibits a much more regular behavior than the amplitude asymmetry; (2) the phase-leading hemisphere returns back to the identical hemisphere every 8 solar cycles, and the secular periodic pattern of hemispheric phase differences follows 3 (south leading) + 5 (north leading) solar cycles, which probably corresponds to the Gleissberg cycle; and (3) the pronounced periodicities of (absolute and normalized) asymmetry indices and lines of synchronization (LOSs) are not identical: the significant periodic oscillations are 80.65 ± 6.31, 20.91 ± 0.40, and 13.45 ± 0.16 years for the LOS values, and 51.34 ± 2.48, 8.83/8.69 ± 0.07, and 3.77 ± 0.02 years for the (absolute and normalized) asymmetry indices. The analysis results improve our knowledge on the hemispheric interrelation of solar magnetic activity and may provide valuable constraints for solar dynamo models.

  11. On anticorrelation of number Coronal Bright Points with sunspot number during 1996-2005

    NASA Astrophysics Data System (ADS)

    Sattarov, I.; Pevtsov, A. A.; Karachik, N. V.; Sherdanov, Ch. T.

    X-ray Bright Points XBP were extensively studied using observations from various instruments Golub at all 1979 have found that number of XBP anticorralates with sunspot number and suggested that solar cycle may be characterized as an oscillator in wavenumber space This finding prompted Yoshmura 1983 to suggest the existence of a secondary cycle of magnetic activity running in opposite phase to the sunspot cycle Later however Nakakubo Hara 2000 concluded that the variation in number of XBPs might be visibility effect as the enhanced brightness of corona may hinder identification of dimmer XBPs Sattarov at al 2002 found that while the number of bright points exhibit cyclic variation the number of magnetic bipoles with a particular flux and separation does not change from solar minimum to the aximum Hence Sattarov et al 2002 concluded that cyclic variation in XBP number may be a visibility effect In this work we continue study the properties of coronal bright points CBPs features that include XBPs and bright points in other wavelengths using SOHO EIT 195A data from 1996-2005 We identify CBPs using automatic procedure developed by us Sattarov et al 2005 Karachik et al 2006 and calculate various parameters including heliographic position intensity area and background intensity around each CBP Analyzing this data we found that the latitude-cycle variations of CBPs cannot be completely explained by the visibility effect These irregularities suggest that in addition to the visibility effect the actual number of coronal bright points

  12. On anticorrelation of number Coronal Bright Points with sunspot number during 1996-2005

    NASA Astrophysics Data System (ADS)

    Sattarov, I.; Pevtsov, A. A.; Karachik, N. V.; Sherdanov, Ch. T.

    X-ray Bright Points XBP were extensively studied using observations from various instruments Golub at all 1979 have found that number of XBP anticorralates with sunspot number and suggested that solar cycle may be characterized as an oscillator in wavenumber space This finding prompted Yoshmura 1983 to suggest the existence of a secondary cycle of magnetic activity running in opposite phase to the sunspot cycle Later however Nakakubo Hara 2000 concluded that the variation in number of XBPs might be visibility effect as the enhanced brightness of corona may hinder identification of dimmer XBPs Sattarov at al 2002 found that while the number of bright points exhibit cyclic variation the number of magnetic bipoles with a particular flux and separation does not change from solar minimum to the maximum Hence Sattarov et al 2002 concluded that cyclic variation in XBP number may be a visibility effect In this work we continue study the properties of coronal bright points CBPs features that include XBPs and bright points in other wavelengths using SOHO EIT 195A data from 1996-2005 We identify CBPs using automatic procedure developed by us Sattarov et al 2005 Karachik et al 2006 and calculate various parameters including heliographic position intensity area and background intensity around each CBP Analyzing this data we found that the latitude-cycle variations of CBPs cannot be completely explained by the visibility effect These irregularities suggest that in addition to the isibility effect the actual number of coronal bright points on

  13. 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.

  14. Photometric measurements of solar irradiance variations due to sunspots

    NASA Technical Reports Server (NTRS)

    Chapman, G. A.; Herzog, A. D.; Laico, D. E.; Lawrence, J. K.; Templer, M. S.

    1989-01-01

    A photometric telescope constructed to obtain photometric sunspot areas and deficits on a daily basis is described. Data from this Cartesian full disk telescope (CFDT) are analyzed with attention given to the period between June 4 and June 17, 1985 because of the availability of overlapping sunspot area and irradiance deficit data from high-resolution digital spectroheliograms made with the San Fernando Observatory 28 cm vacuum solar telescope and spectroheliograph. The CFDT sunspot deficits suggest a substantial irradiance contribution from faculae and active region plage.

  15. Oscillations above sunspots: Evidence for propagating waves?

    NASA Astrophysics Data System (ADS)

    O'Shea, E.; Muglach, K.; Fleck, B.

    2002-05-01

    We present results of an analysis of time series data observed in sunspot umbral regions. The data were obtained in the context of the SOHO Joint Observing Program (JOP) 97 in September 2000. This JOP included the Coronal Diagnostic Spectrometer (CDS) and the Michelson Doppler Imaging (MDI) instrument, both part of SOHO, the TRACE satellite and various ground based observatories. The data was analysed by using both Fourier and wavelet time series analysis techniques. We find that oscillations are present in the umbra at all temperatures investigated, from the temperature minimum as measured by TRACE 1700 Å up to the upper corona as measured by CDS Fe Xvi 335 Å (log T=6.4 K). Oscillations are found to be present with frequencies in the range of 5.4 mHz (185 s) to 8.9 mHz (112 s). Using the techniques of cross-spectral analysis time delays were found between low and high temperature emission suggesting the possibility of both upward and downward wave propagation. It is found that there is typically a good correlation between the oscillations measured at the different emission temperatures, once the time delays are taken into account. We find umbral oscillations both inside and outside of sunspot plume locations which indicates that umbral oscillations can be present irrespective of the presence of these sunspot plumes. We find that a number of oscillation frequencies can exist co-spatially and simultaneously i.e. for one pixel location three different frequencies at 5.40, 7.65 and 8.85 mHz were measured. We investigate the variation of the relative amplitudes of oscillation with temperature and find that there is a tendency for the amplitudes to reach a maximum at the temperature of O Iii (and less typically O V and Mg Ix) and then to decrease to reach a minimum at the temperature of Mg X (log T=6.0 K), before increasing again at the temperature of Fe Xvi. We discuss a number of possible theoretical scenarios that might explain these results. From a measurement of

  16. 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.

  17. STOCHASTIC DESCRIPTION OF THE HIGH-FREQUENCY CONTENT OF DAILY SUNSPOTS AND EVIDENCE FOR REGIME CHANGES

    SciTech Connect

    Shapoval, A.; Le Mouël, J.-L.; Courtillot, V.; Shnirman, M.

    2015-01-20

    The irregularity index λ is applied to the high-frequency content of daily sunspot numbers ISSN. This λ is a modification of the standard maximal Lyapunov exponent. It is computed here as a function of embedding dimension m, within four-year time windows centered at the maxima of Schwabe cycles. The λ(m) curves form separate clusters (pre-1923 and post-1933). This supports a regime transition and narrows its occurrence to cycle 16, preceding the growth of activity leading to the Modern Maximum. The two regimes are reproduced by a simple autoregressive process AR(1), with the mean of Poisson noise undergoing 11 yr modulation. The autocorrelation a of the process (linked to sunspot lifetime) is a ≈ 0.8 for 1850-1923 and ≈0.95 for 1933-2013. The AR(1) model suggests that groups of spots appear with a Poisson rate and disappear at a constant rate. We further applied the irregularity index to the daily sunspot group number series for the northern and southern hemispheres, provided by the Greenwich Royal Observatory (RGO), in order to study a possible desynchronization. Correlations between the north and south λ(m) curves vary quite strongly with time and indeed show desynchronization. This may reflect a slow change in the dimension of an underlying dynamical system. The ISSN and RGO series of group numbers do not imply an identical mechanism, but both uncover a regime change at a similar time. Computation of the irregularity index near the maximum of cycle 24 will help in checking whether yet another regime change is under way.

  18. Salient Features of the New Sunspot Number Time Series

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.; Ygbuhay, R. C.

    2016-12-01

    Recently Clette et al. (Space Sci. Rev. 186, 35, 2014) completed the first revision of the international sunspot number SSN(V2) since its creation by Wolf in 1849 SSN(V1) starting in 1700 and ending in May 2015. The yearly values of SSN(V2) are larger than those of SSN(V1) but the secular trend in their timelines both exhibit a gradual descent after Cycle 21 minimum resulting in greatly reduced activity for Cycle 24. It has two peaks; one in 2012 due to activity in the north hemisphere (NH) and the other in 2014 due to excess activity in the south hemisphere (SH). The N-S excess of hemispheric SSNs is examined for 1950 - 2014, in relation to the time variations of the solar polar field for 1976 - 2015, covering five complete solar cycles (19 - 23) and parts of the bordering two (18, 24). We find that SH tends to become progressively more active in the declining phase of the cycles reaching an extreme value that gave rise to a second higher peak in October 2014 in the smoothed SSNs accompanied by a strong solar polar field in SH. There may be a Gleissberg cyclicity in the asymmetric solar dynamo operation. The continuing descent of the secular trend in SSNs implies that we may be near a Dalton-level grand minimum. The low activity spell may last well past 2060, accompanied by a stable but reduced level of the space weather/climate. Fourier spectrum of the time domain of SSNs shows no evidence of the 208 year/cycle (ypc) (DeVries/Suess cycle) seen in the cosmogenic radionuclide ({}^{10}Be) concentration in the polar ice cores and {}^{14}C record in trees indicating that 208 ypc peak may be of non-solar origin. It may arise from the climate process(es) that change(s) the way radionuclides are deposited on polar ice. It should be noted that we only have {˜} 400 years of SSN data, so it is possible that DeVries/Suess cycle is really driven by the Sun but for now we do not have any evidence of that; there is no known physical process linking 208 ypc to solar dynamo

  19. Correlation Between Sunspot Number and Ca ii K Emission Index

    NASA Astrophysics Data System (ADS)

    Bertello, Luca; Pevtsov, Alexei; Tlatov, Andrey; Singh, Jagdev

    2016-11-01

    Long-term synoptic observations in the resonance line of Ca ii K constitute a fundamental database for a variety of retrospective analyses of the state of the solar magnetism. Synoptic Ca ii K observations began in late 1904 at the Kodaikanal Observatory in India. In the early 1970s, the National Solar Observatory (NSO) at Sacramento Peak (USA) started a new program of daily Sun-as-a-star observations in the Ca ii K line. Today the NSO is continuing these observations through its Synoptic Optical Long-term Investigations of the Sun (SOLIS) facility. These different data sets can be combined into a single disk-integrated Ca ii K index time series that describes the average properties of the chromospheric emission over several solar cycles. We present such a Ca ii K composite and discuss its correlation with the new entirely revised sunspot number data series. For this preliminary investigation, the scaling factor between pairs of time series was determined assuming a simple linear model for the relationship between the monthly mean values during the duration of overlapping observations.

  20. Amplitudes of MHD Waves in Sunspots

    NASA Astrophysics Data System (ADS)

    Norton, Aimee Ann; Cally, Paul; Baldner, Charles; Kleint, Lucia; Tarbell, Theodore D.; De Pontieu, Bart; Scherrer, Philip H.; Rajaguru, Paul

    2016-05-01

    The conversion of p-modes into MHD waves by strong magnetic fields occurs mainly in the sub-photospheric layers. The photospheric signatures of MHD waves are weak due to low amplitudes at the beta=1 equipartion level where mode-conversion occurs. We report on small amplitude oscillations observed in the photosphere with Hinode SOT/SP in which we analyze time series for sunspots ARs 12186 (11.10.2014) and 12434 (17.10.2015). No significant magnetic field oscillations are recovered in the umbra or penumbra in the ME inversion. However, periodicities in the inclination angle are found at the umbral/penumbral boundary with 5 minute periods. Upward propagating waves are indicated in the intensity signals correlated between HMI and AIA at different heights. We compare SP results with the oscillations observed in HMI data. Simultaneous IRIS data shows transition region brightening above the umbral core.

  1. Rapid Sunspot Displacement Associated with Solar Eruptions

    NASA Astrophysics Data System (ADS)

    Liu, Chang; Deng, N.; Wang, H.

    2010-05-01

    Many observational and modeling studies of solar eruptions merely treat photosphere as the lower boundary and assume no significant changes of magnetic fields anchoring there to occur during flares/CMEs. With increasing evidence of photospheric magnetic fields variations resulting from energy release in the upper atmosphere, Hudson, Fisher and Welsch (2008, ASP, 383, 221) proposed that the photosphere and even solar interior would respond in a back-reaction process to the coronal magnetic field restructuring. Inspired by this concept, we analyzed white-light images obtained with TRACE and report here rapid and permanent perturbation in the position of delta spot umbrae associated with five X-class flares. Our main results are the following: (1) The centroids of umbrae with opposite magnetic polarities undergo relative as well as overall displacement on the order of 1E3 km after flares/CMEs. (2) The estimated total kinetic energy associated with these motions (Ek) is on the order of 1E29 ergs and appears to correlate with the 6 mHZ seismic energy (Es) derived by the Monash group. (3) There appears correlation between both the Ek and Es corresponding to the velocity of CMEs. We suggest that: (1) sunspot displacement provides a direct observational evidence of the photospheric back-reaction and could potentially serve as an alternative excitation mechanism of seismic waves; (2) These could provide rational support to the back-reaction mechanism in the sense that its magnitude might be related to how violent the coronal magnetic field is disrupted. For selected events with good multiwavelength coverage, we also analyze in detail spatial as well as temporal relationship among the sunspot displacement, magnetic field changes, seismic sources, hard X-ray emissions, and overall flaring condition. This work is supported by NSF grants ATM 08-19662 and ATM 07-45744, and NASA grants NNX 08AQ90G, NNX 07AH78G, and NNX 08AQ32G.

  2. Drag and energy accommodation coefficients during sunspot maximum

    NASA Astrophysics Data System (ADS)

    Pardini, Carmen; Anselmo, Luciano; Moe, Kenneth; Moe, Mildred M.

    over 30-day intervals from October 1999 to December 2002, was found to be 2.16. When the measurement was adjusted upward by 12 % to correct for the bias in the density model, the resulting physical drag coefficient became 2.42. Comparison of this result with the calculated dependence of the drag coefficient of SNOE on the energy accommodation coefficient has revealed agreement for α = 0.97. This high an accommodation coefficient implies that a considerable portion of the satellite surface had oxygen atoms adsorbed on it. This is physically reasonable because during sunspot maximum the increased solar UV radiation dissociates more molecular oxygen and the UV heating causes the atmosphere to expand to higher altitudes. The analysis was carried out for several satellites, having perigee altitudes between 300 and 800 km, during the last solar cycle maximum. This sample included a subset of Surrey satellites, for which the main characteristics (i.e. size, shape, mass, attitude, etc.) were known, and some spherical, or nearly spherical, objects.

  3. [Acute bilateral impaired vision with central scotoma in an 11-year-old boy].

    PubMed

    Pollithy, S; Ach, T; Schaal, K B; Dithmar, S

    2012-09-01

    This article presents a case of acute bilateral impaired vision and central scotoma in an 11-year-old boy. Looking directly into a laser beam of a laser pointer for only a few seconds can cause retinal damage in the form of lesions of the retinal pigment epithelium and the photoreceptor layer, up to retinal hemorrhage. Patients often complain about impaired vision and a central scotoma of the affected eye.

  4. The transmission of tuberculosis in schools involving children 3 to 11 years of age.

    PubMed

    Roberts, Jonathan R; Mason, Brendan W; Paranjothy, Shantini; Palmer, Stephen R

    2012-01-01

    Little is known about the risk of tuberculosis transmission from children. We reviewed the published literature on the transmission of tuberculosis during outbreaks involving children 3 to 11 years of age and report that transmission rates among close contacts in school outbreaks are on average higher (weighted average 69.8% vs. 39.3%) if the index case is a child than an adult.

  5. Orthodontic treatment for a patient with advanced periodontal disease: 11-year follow-up.

    PubMed

    Tavares, Carlos Alberto Estevanell; Allgayer, Susiane; Calvete, Ernani da Silva; Polido, Waldemar Daudt

    2013-09-01

    This case report demonstrates the interdisciplinary treatment of an adult patient with a Class II malocclusion, convex profile, incompetent lips, gummy smile, and advanced periodontal loss. Initial periodontal-endodontic treatment was followed by orthodontic and orthognathic surgical therapies. An esthetic facial profile, a pleasing smile, an appropriate occlusion, and overall good treatment outcomes, including the periodontal condition, remained stable 11 years after active orthodontic treatment.

  6. Musculoskeletal complaints among 11-year-old children and associated factors: the PIAMA birth cohort study.

    PubMed

    Hulsegge, Gerben; van Oostrom, Sandra H; Picavet, H Susan J; Twisk, Jos W R; Postma, Dirkje S; Kerkhof, Marjan; Smit, Henriëtte A; Wijga, Alet H

    2011-10-15

    Musculoskeletal complaints (MSC) are common among children, often persist into adolescence, and increase the risk of MSC in adulthood. Knowledge regarding determinants of MSC among children is limited. The aim of this study was to determine the prevalence of MSC at age 11 years and to examine associations with sociodemographic factors, growth and development factors, mental health, tiredness, and lifestyle. Data from a Netherlands birth cohort study, the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) Study (n = 2,638), were used (1996-2009). MSC were defined as complaints about the back, an upper extremity, a lower extremity, or any of these sites. Logistic regression analyses using a forward stepwise procedure were performed on multiply imputed data. The 1-year period prevalences of back, upper extremity, and lower extremity complaints that lasted at least 1 month were 2.8%, 4.8%, and 10.9%, respectively. Only poorer mental health was consistently associated with all 3 types of complaints. Poorer mental health, daytime tiredness, early pubertal development, being physically active at age 11 years, and weight-for-height z score were associated with having any MSC. This study showed that MSC, especially lower extremity complaints, are common among 11-year old-children and that only poorer mental health status is associated with MSC at all anatomic sites.

  7. Volcanism, Cold Temperature, and Paucity of Sunspot Observing Days (1818-1858): A Connection?

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1998-01-01

    During the interval of 1818-1858, several curious decreases in the number of sunspot observing days per year are noted in the observing record of Samuel Heinrich Schwabe, the discoverer of the sunspot cycle, and in the reconstructed record of Rudolf Wolf, the founder of the now familiar relative sunspot number. These decreases appear to be nonrandom in nature and often extended for 13 yr (or more). Comparison of these decreases with equivalent annual mean temperature (both annual means and 4-yr moving averages). as recorded at Armagh Observatory (Northern Ireland), indicates that the temperature during the years of decreased number of observing days trended downward near the start of' each decrease and upward (suggesting some sort of recovery) just before the end of each decrease. The drop in equivalent annual mean temperature associated with each decrease, as determined from the moving averages, measured about 0.1-0.7 C. The decreases in number of observing days are found to be closely related to the occurrences of large, cataclysmic volcanic eruptions in the tropics or northern hemisphere. In particular, the interval of increasing number of observing days at the beginning of the record (i.e., 1818-1819) may be related to the improving atmospheric conditions in Europe following the 1815 eruption of Tambora (Indonesia; 8 deg. S), which previously, has been linked to "the year without a summer" (in 1816) and which is the strongest eruption in recent history, while the decreases associated with the years of 1824, 1837, and 1847 may, be linked, respectively, to the large, catacivsmic volcanic eruptions of Galunggung (Indonesia; 7 deg. S) in 1822, Cosiguina (Nicaragua) in 1835, and, perhaps, Hekla (Iceland; 64 deg. N) in 1845. Surprisingly, the number of observing days per year, as recorded specifically b), SchAabe (from Dessau, Germany), is found to be linearly correlated against the yearly mean temperature at Armagh Observatory (r = 0.5 at the 2 percent level of

  8. Automatic Recognition of Sunspots in HSOS Full-Disk Solar Images

    NASA Astrophysics Data System (ADS)

    Zhao, Cui; Lin, GangHua; Deng, YuanYong; Yang, Xiao

    2016-05-01

    A procedure is introduced to recognise sunspots automatically in solar full-disk photosphere images obtained from Huairou Solar Observing Station, National Astronomical Observatories of China. The images are first pre-processed through Gaussian algorithm. Sunspots are then recognised by the morphological Bot-hat operation and Otsu threshold. Wrong selection of sunspots is eliminated by a criterion of sunspot properties. Besides, in order to calculate the sunspots areas and the solar centre, the solar limb is extracted by a procedure using morphological closing and erosion operations and setting an adaptive threshold. Results of sunspot recognition reveal that the number of the sunspots detected by our procedure has a quite good agreement with the manual method. The sunspot recognition rate is 95% and error rate is 1.2%. The sunspot areas calculated by our method have high correlation (95%) with the area data from the United States Air Force/National Oceanic and Atmospheric Administration (USAF/NOAA).

  9. Sunspots Resource--From Ancient Cultures to Modern Research

    NASA Astrophysics Data System (ADS)

    Craig, N.

    2000-10-01

    Sunspots is a web-based lesson that was developed by the Science Education Gateway (SEGway) program with participants from the Exploratorium, a well known science Museum in San Francisco, UC Berkeley Space Sciences Laboratory, and teachers from several California schools. This space science resource allows 8-12 grade students to explore the nature of sunspots and the history of solar physics in its effort to understand their nature. Interviews with solar physicists and archeo-astronomers, historic images, cutting-edge NASA images, movies, and research results, as well as a student-centered sunspot research activity using NASA space science data defines this lesson. The sunspot resource is aligned with the NCTM and National Science Education Standards. It emphasizes inquiry-based methods and mathematical exercises through measurement, graphic data representation, analysis of NASA data, lastly, interpreting results and drawing conclusions. These resources have been successfully classroom tested in 4 middle schools in the San Francisco Unified School District as part of the 3-week Summer School Science curricula. Lessons learned from the Summer School 1999 will be explained. This resource includes teacher-friendly lesson plans, space science background material and student worksheets. There will be Sunspots lesson CD-ROM and printed version of the relevant classroom-ready materials and a teacher resource booklet available. Sunspot resource is brought to you by, The Science Education Gateway - SEGway - Project, and the HESSI satellite and NASA's Office of Space Science Sun-Earth Connection Education Forum.

  10. Are the photospheric sunspots magnetically force-free in nature?

    NASA Astrophysics Data System (ADS)

    Tiwari, Sanjiv Kumar

    2011-08-01

    In a force-free magnetic field, there is no interaction of field and the plasma in the surrounding atmosphere i.e., electric currents are aligned with the magnetic field, giving rise to zero Lorentz force. The computation of many magnetic parameters like magnetic energy, gradient of twist of sunspot magnetic fields (computed from the force-free parameter α), including any kind of extrapolations heavily hinge on the force-free approximation of the photospheric magnetic fields. The force-free magnetic behaviour of the photospheric sunspot fields has been examined by Metcalf et al. (1995) and Moon et al. (2002) ending with inconsistent results. Metcalf et al. (1995) concluded that the photospheric magnetic fields are far from the force-free nature whereas Moon et al. (2002) found the that the photospheric magnetic fields are not so far from the force-free nature as conventionally regarded. The accurate photospheric vector field measurements with high resolution are needed to examine the force-free nature of sunspots. We use high resolution vector magnetograms obtained from the Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) aboard Hinode to inspect the force-free behaviour of the photospheric sunspot magnetic fields. Both the necessary and sufficient conditions for force-freeness are examined by checking global as well as as local nature of sunspot magnetic fields. We find that the sunspot magnetic fields are very close to the force-free approximation, although they are not completely force-free on the photosphere.

  11. INTERFERENCE FRINGES OF SOLAR ACOUSTIC WAVES AROUND SUNSPOTS

    SciTech Connect

    Chou, Dean-Yi; Zhao Hui; Yang, Ming-Hsu; Liang, Zhi-Chao

    2012-10-20

    Solar acoustic waves are scattered by a sunspot due to the interaction between the acoustic waves and the sunspot. The sunspot, excited by the incident wave, generates the scattered wave. The scattered wave is added to the incident wave to form the total wave around the sunspot. The interference fringes between the scattered wave and the incident wave are visible in the intensity of the total wave because the coherent time of the incident wave is of the order of a wave period. The strength of the interference fringes anti-correlates with the width of temporal spectra of the incident wave. The separation between neighboring fringes increases with the incident wavelength and the sunspot size. The strength of the fringes increases with the radial order n of the incident wave from n = 0 to n = 2, and then decreases from n = 2 to n = 5. The interference fringes play a role analogous to holograms in optics. This study suggests the feasibility of using the interference fringes to reconstruct the scattered wavefields of the sunspot, although the quality of the reconstructed wavefields is sensitive to the noise and errors in the interference fringes.

  12. MAGNETIC TOPOLOGY OF A NAKED SUNSPOT: IS IT REALLY NAKED?

    SciTech Connect

    Sainz Dalda, A.; Vargas Dominguez, S.; Tarbell, T. D.

    2012-02-10

    The high spatial, temporal, and spectral resolution achieved by Hinode instruments gives much better understanding of the behavior of some elusive solar features, such as pores and naked sunspots. Their fast evolution and, in some cases, their small sizes have made their study difficult. The moving magnetic features (MMFs) have been studied during the last 40 years. They have been always associated with sunspots, especially with the penumbra. However, a recent observation of a naked sunspot (one with no penumbra) has shown MMF activity. The authors of this reported observation expressed their reservations about the explanation given to the bipolar MMF activity as an extension of the penumbral filaments into the moat. How can this type of MMF exist when a penumbra does not? In this Letter, we study the full magnetic and (horizontal) velocity topology of the same naked sunspot, showing how the existence of a magnetic field topology similar to that observed in sunspots can explain these MMFs, even when the intensity map of the naked sunspot does not show a penumbra.

  13. Contributions of Active Regions, Sunspots, Quiet Sun to the Solar UV Spectrum

    NASA Astrophysics Data System (ADS)

    Morrill, J. S.; McMullin, D. R.; Cookson, A.; Chapman, G. A.

    2011-12-01

    During the declining phase of the most recent solar cycle, the full disk solar UV spectrum was measured by several space-based instruments, including the SOLSTICE and SIM instruments on the SORCE satellite and the SUSIM instrument on the UARS satellite. These results show distinctively different behavior and have implications for our understanding of the contributions played by various surface features in producing the disk integrated UV spectrum as well as the impact of solar UV emissions on climate. The primary goal of this study is to determine the impact of regions of increased activity (e.g. plage and sunspots) during the recent solar cycle and how this relates to variability of the solar spectrum. Two important results from this study will be the plage and sunspot UV contrast compared to the quiet as well as the center to limb variability of plage, sunspots, and the quiet sun at UV wavelengths. This study will estimate the solar spectrum by utilizing the recently digitized UV spectral radiance observations of plage, sunspots, the quiet sun made by the S082B spectrograph on Skylab, Ca II K images collected at San Fernando Observatory during the recent solar cycle, and a solar spectral model developed under a previous NASA grant. Once generated, these spectra will be compared to the UV observations produced by the above instruments. An important step in the estimation process involves the calibration of the Skylab data for a valid comparison between model and observed spectra. This will require separate calibration curves for SUSIM and SORCE observations. These will be generated from days of no or minimal activity. The determination of separate calibrations will allow any subtle contributions due to variations in instrument performance to be accounted for in the comparison of model and observed spectra. Also, changes in instrumental behavior over time will be separable from real changes in the solar spectrum which are due to contributions of active solar

  14. Contributions of Active Regions, Sunspots, Quiet Sun to the Solar UV Spectrum

    NASA Astrophysics Data System (ADS)

    Morrill, J. S.; McMullin, D. R.; Cookson, A.; Chapman, G. A.

    2013-12-01

    During the declining phase of the most recent solar cycle, the full disk solar UV spectrum was measured by several space-based instruments, including the SOLSTICE and SIM instruments on the SORCE satellite and the SUSIM instrument on the UARS satellite. These results show distinctively different behavior and have implications for our understanding of the contributions played by various surface features in producing the disk integrated UV spectrum as well as the impact of solar UV emissions on climate. The primary goal of this study is to determine the impact of regions of increased activity (e.g. plage and sunspots) during the recent solar cycle and how this relates to variability of the solar spectrum. Two important results from this study will be the plage and sunspot UV contrast compared to the quiet as well as the center to limb variability of plage, sunspots, and the quiet sun at UV wavelengths. This study will estimate the solar spectrum by utilizing the recently digitized UV spectral radiance observations of plage, sunspots, the quiet sun made by the S082B spectrograph on Skylab, Ca II K images collected at San Fernando Observatory during the recent solar cycle, and a solar spectral model developed under a previous NASA grant. Once generated, these spectra will be compared to the UV observations produced by the above instruments. An important step in the estimation process involves the calibration of the Skylab data for a valid comparison between model and observed spectra. This will require separate calibration curves for SUSIM and SORCE observations. These will be generated from days of no or minimal activity. The determination of separate calibrations will allow any subtle contributions due to variations in instrument performance to be accounted for in the comparison of model and observed spectra. Also, changes in instrumental behavior over time will be separable from real changes in the solar spectrum which are due to contributions of active solar

  15. On dependence of seismic activity on 11 year variations in solar activity and/or cosmic rays

    NASA Astrophysics Data System (ADS)

    Zhantayev, Zhumabek; Khachikyan, Galina; Breusov, Nikolay

    2014-05-01

    It is found in the last decades that seismic activity of the Earth has a tendency to increase with decreasing solar activity (increasing cosmic rays). A good example of this effect may be the growing number of catastrophic earthquakes in the recent rather long solar minimum. Such results support idea on existence a solar-lithosphere relationship which, no doubts, is a part of total pattern of solar-terrestrial relationships. The physical mechanism of solar-terrestrial relationships is not developed yet. It is believed at present that one of the main contenders for such mechanism may be the global electric circuit (GEC) - vertical current loops, piercing and electrodynamically coupling all geospheres. It is also believed, that the upper boundary of the GEC is located at the magnetopause, where magnetic field of the solar wind reconnects with the geomagnetic field, that results in penetrating solar wind energy into the earth's environment. The effectiveness of the GEC operation depends on intensity of cosmic rays (CR), which ionize the air in the middle atmosphere and provide its conductivity. In connection with the foregoing, it can be expected: i) quantitatively, an increasing seismic activity from solar maximum to solar minimum may be in the same range as increasing CR flux; and ii) in those regions of the globe, where the crust is shipped by the magnetic field lines with number L= ~ 2.0, which are populated by anomalous cosmic rays (ACR), the relationship of seismic activity with variations in solar activity will be manifested most clearly, since there is a pronounced dependence of ACR on solar activity variations. Checking an assumption (i) with data of the global seismological catalog of the NEIC, USGS for 1973-2010, it was found that yearly number of earthquake with magnitude M≥4.5 varies into the 11 year solar cycle in a quantitative range of about 7-8% increasing to solar minimum, that qualitatively and quantitatively as well is in agreement with the

  16. 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.

  17. 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.

  18. Interactions between nested sunspots. 1: The formation and breakup of a delta-type sunspot

    NASA Technical Reports Server (NTRS)

    Gaizauskas, V.; Harvey, K. L.; Proulx, M.

    1994-01-01

    We investigate a nest of sunspots in which three ordinary bipolar pairs of sunspots are aligned collinearly. The usual spreading action of the growing regions brings two spots of leading polarity together (p-p collision) and forces the leading and trailing spots of the two interior regions to overlap inot a single penumbra (p-f collision), thus forming a delta-spot. We examine digitally processed images from the Ottawa River Solar Observatory of two related events inside the delta-spot 5 days after the p-f collision begins: the violent disruption of the f-umbra, and the formation in less than a day of an hydrogen-alpha filament. The evolutionary changes in shape, area, relative motions, and brightness that we measure for each spot in the elongated nest are more compatible with Parker's (1979a) hypothesis of a sunspot as a cluster of flux tubes held together by downdrafts than with the notion of a sunspot as a monolithic plug of magnetic flux. From chromospheric developments over the delta-spot, we show that a shearing motion along a polarity inversion is more effective than convergence for creating a chromospheric filament. We invoke the release of an instability, triggered by a sequence of processes lasting 1 day or more, to explain the disruption of the f-umbra in this delta-spot. We show that the sequence is initiated when the colliding p-f umbrae reach a critical separation around 3200 +/- 200 km. We present a descriptive model in which the reconnected magnetic fields block vertical transport of convective heat flux just beneath the photosphere. We observe the formation of an unusual type of penumbra adjacent to the f-polarity portion of this delta-spot just before its disruption. A tangential penumbral band grows out of disordered matter connected to the f-umbra. We present this as evidence for the extrusion of umbral magnetic flux by thermal plumes rising through a loosely bound umbra.

  19. Interactions between nested sunspots. 1: The formation and breakup of a delta-type sunspot

    NASA Astrophysics Data System (ADS)

    Gaizauskas, V.; Harvey, K. L.; Proulx, M.

    1994-02-01

    We investigate a nest of sunspots in which three ordinary bipolar pairs of sunspots are aligned collinearly. The usual spreading action of the growing regions brings two spots of leading polarity together (p-p collision) and forces the leading and trailing spots of the two interior regions to overlap into a single penumbra (p-f collision), thus forming a delta-spot. We examine digitally processed images from the Ottawa River Solar Observatory of two related events inside the delta-spot 5 days after the p-f collision begins: the violent disruption of the f-umbra, and the formation in less than a day of an hydrogen-alpha filament. The evolutionary changes in shape, area, relative motions, and brightness that we measure for each spot in the elongated nest are more compatible with Parker's (1979a) hypothesis of a sunspot as a cluster of flux tubes held together by downdrafts than with the notion of a sunspot as a monolithic plug of magnetic flux. From chromospheric developments over the delta-spot, we show that a shearing motion along a polarity inversion is more effective than convergence for creating a chromospheric filament. We invoke the release of an instability, triggered by a sequence of processes lasting 1 day or more, to explain the disruption of the f-umbra in this delta-spot. We show that the sequence is initiated when the colliding p-f umbrae reach a critical separation around 3200 +/- 200 km. We present a descriptive model in which the reconnected magnetic fields block vertical transport of convective heat flux just beneath the photosphere. We observe the formation of an unusual type of penumbra adjacent to the f-polarity portion of this delta-spot just before its disruption. A tangential penumbral band grows out of disordered matter connected to the f-umbra. We present this as evidence for the extrusion of umbral magnetic flux by thermal plumes rising through a loosely bound umbra.

  20. An international comparison of dietary patterns in 9–11-year-old children

    PubMed Central

    Mikkilä, V; Vepsäläinen, H; Saloheimo, T; Gonzalez, S A; Meisel, J D; Hu, G; Champagne, C M; Chaput, J-P; Church, T S; Katzmarzyk, P T; Kuriyan, R; Kurpad, A; Lambert, E V; Maher, C; Maia, J; Matsudo, V; Olds, T; Onywera, V; Sarmiento, O L; Standage, M; Tremblay, M S; Tudor-Locke, C; Zhao, P; Fogelholm, M

    2015-01-01

    OBJECTIVES: Dietary pattern is defined as a combination of foods and drinks and the frequency of consumption within a population. Dietary patterns are changing on a global level, which may be linked to an increased incidence of chronic diseases. The aim of this study was to identify and compare the dietary patterns among 9–11-year-old children living in urban regions in different parts of the world. METHODS: Participants were 7199 children (54% girls), aged 9–11 years, from 12 countries situated in all major world regions. Food consumption was assessed using a 23-item Food Frequency Questionnaire (FFQ). To identify dietary patterns, principal components analyses (PCA) were carried out using weekly portions as input variables. RESULTS: Both site-specific and pooled PCA resulted in two strong components. Component 1 (‘unhealthy diet pattern') included fast foods, ice cream, fried food, French fries, potato chips, cakes and sugar-sweetened sodas with >0.6 loadings. The loadings for component 2 (‘healthy diet pattern') were slightly weaker with only dark-green vegetables, orange vegetables, vegetables in general, and fruits and berries reaching a >0.6 loading. The site-specific diet pattern scores had very strong correlations with the pattern scores from the pooled data: r=0.82 and 0.94 for components 1 and 2, respectively. CONCULSIONS: The results suggest that the same ‘healthier' and ‘unhealthier' foods tend to be consumed in similar combinations among 9–11-year-old children in different countries, despite variation in food culture, geographical location, ethnic background and economic development. PMID:27152179

  1. Dexa Body Composition Assessment in 10-11 Year Healthy Children

    PubMed Central

    Doodeman, H. J.; Struijf, E.; Houdijk, A. P. J.

    2016-01-01

    Introduction Obesity is a growing health problem associated with metabolic derangements and cardiovascular disease. Accumulating evidence links the accumulation of visceral adipose tissue (VAT) to these obesity related health risks in adults. Childhood obesity is associated with a lifetime risk of cardiovascular disease and poses a serious challenge to future health care. In children, there is much less data on the prevalence and gender differences of visceral obesity than in adults. This study aims to provide reference values for VAT in children 10–11 years of age. Methods In a cross-sectional study performed in the north western part of theNetherlands, healthy children of 10–11 years of age, were recruited from primary schools. Anthropometric data consisting of height, weight, waist circumference (WC) and BMI were measured. Body composition was measured using DXA, providing measures for bone mineral content, total fat mass (TFM), lean body mass (LBM) and VAT. Results 217 children were eligible for this study. Girls appeared to have a greater TFM (31.4% vs 27.5% of total body weight (TBW); P < .01) but lower VAT (0.3% vs 0.5% of TBW;P < .01) than boys, whereas boys had higher LBM (65.4% vs 69.3% TBW;P < .01). Median VAT area (cm2) was 41.1 for boys and 22.4 for girls (P < .01). Moderate to strong correlations were found for WC and BMI with VAT (boys: r = .664 and r = .630; Girls r = .699 and r = .546 respectively all P < .001). Discussion This study shows gender specific differences in VAT percentiles in healthy non-obese 10–11 year old children as measured by DXA that may serve as reference values in children. Independent of BMI and WC, girls tend to have more TFM but less VAT and LBM than boys. PMID:27788168

  2. Brain abscess secondary to a dental infection in an 11-year-old child: case report.

    PubMed

    Hibberd, Christine E; Nguyen, Trang D

    2012-01-01

    A primary molar dental abscess was implicated as the cause of a brain abscess in an 11-year-old boy. This case report describes the neurological signs and symptoms, and acute management of a brain abscess in a child. A brain abscess is provisionally diagnosed from the patient's medical history, as well as the presence of signs and symptoms such as fever, headache, nausea, vomiting, focal neurological deficit, altered mentation, speech alterations, papillary edema, and neck stiffness or seizures. A definitive diagnosis of brain abscess is confirmed through imaging. The dental source of infection is identified by the exclusion of more probable foci such as the ears, heart, lungs, eyes or sinuses.

  3. Enterobius granuloma: an unusual cause of omental mass in an 11-year-old girl.

    PubMed

    Kılıç, Sinan; Ekinci, Saniye; Orhan, Diclehan; Senocak, Mehmet Emin

    2014-01-01

    Enterobius vermicularis (pinworm) is the only nematode that infects humans. It is one of the most common intestinal parasites. Pinworm commonly infests the terminal ileum and colon, and does not cause severe morbidity unless ectopic infection occurs. However, granulomatous lesions caused by ectopic Enterobius vermicularis infection may lead to unusual clinical symptoms and may be misinterpreted as malignant lesions. Herein, the authors present an 11-year-old girl with pinworm infection who presented with abdominal pain and an omental mass, with special emphasis on the diagnosis and treatment.

  4. Isolated ileal ganglioneuromatosis in an 11-year-old boy: Case report and review of literature.

    PubMed

    Mitra, Subhashis; Mukherjee, Sanghamitra; Chakraborty, Hema

    2016-01-01

    Ganglioneuromatous proliferation in the gastrointestinal tract is a rare occurrence and is usually associated with specific syndrome complexes such as multiple endocrine neoplasia Type 2B or von Recklinghausen's disease. We report here a case of diffuse intestinal ganglioneuromatosis, presenting as intestinal obstruction and chronic constipation in an 11-year-old boy. Sporadic cases of intestinal ganglioneuromatosis in the absence of any systemic manifestations are a very rare cause of enteric motility disorders in childhood, and we discuss the pathological and clinical significance of this finding. Histopathological identification of this uncommon cause of a common pediatric problem is important since the condition is amenable to surgical treatment.

  5. SEISMIC DISCRIMINATION OF THERMAL AND MAGNETIC ANOMALIES IN SUNSPOT UMBRAE

    SciTech Connect

    Lindsey, C.; Cally, P. S.; Rempel, M.

    2010-08-20

    Efforts to model sunspots based on helioseismic signatures need to discriminate between the effects of (1) a strong magnetic field that introduces time-irreversible, vantage-dependent phase shifts, apparently connected to fast- and slow-mode coupling and wave absorption and (2) a thermal anomaly that includes cool gas extending an indefinite depth beneath the photosphere. Helioseismic observations of sunspots show travel times considerably reduced with respect to equivalent quiet-Sun signatures. Simulations by Moradi and Cally of waves skipping across sunspots with photospheric magnetic fields of order 3 kG show travel times that respond strongly to the magnetic field and relatively weakly to the thermal anomaly by itself. We note that waves propagating vertically in a vertical magnetic field are relatively insensitive to the magnetic field, while remaining highly responsive to the attendant thermal anomaly. Travel-time measurements for waves with large skip distances into the centers of axially symmetric sunspots are therefore a crucial resource for discrimination of the thermal anomaly beneath sunspot umbrae from the magnetic anomaly. One-dimensional models of sunspot umbrae based on compressible-radiative-magnetic-convective simulations such as by Rempel et al. can be fashioned to fit observed helioseismic travel-time spectra in the centers of sunspot umbrae. These models are based on cooling of the upper 2-4 Mm of the umbral subphotosphere with no significant anomaly beneath 4.5 Mm. The travel-time reductions characteristic of these models are primarily a consequence of a Wilson depression resulting from a strong downward buoyancy of the cooled umbral medium.

  6. Er:YAG laser ablation: 5-11 years prospective study

    NASA Astrophysics Data System (ADS)

    Dostalova, Tatjana; Jelinkova, Helena; Nemec, Michal; Sulc, Jan; Miyagi, Mitsunobu

    2005-03-01

    The Er:YAG laser at 2940 nm has been proposed for use in dental cavity preparation and removal of carious enamel and dentin. The purpose of the present study was to determine the effect of the Er:YAG laser ablation in treating dental caries after a period from 5 to 11 years. For this study, 133 cavities were chosen, and for their reparation of it the three restorative materials were used. Baseline examination was made in the following intervals: one week, 1 year, and from 5 to 11 years after cavity preparation and placement of filling material. Clinical assessments were carried out in accordance with the US Public Health Service System. The follow-up included: the marginal ridge, marginal adaptation, anatomic form, caries, color match, cavo surface margin discoloration, surface smoothness, and postoperative sensitivity. Er:YAG laser ablation is an excellent method for treating frontal teeth, i.e., incisors, canines, premolars, and initial occlusal caries of molars. However, visual control of non-contact therapy is necessary. Er:YAG laser ablation is safe, and it strongly reduces pain. The laser treatment markedly decreases the unpleasant sound and vibration.

  7. Gorlin-Goltz Syndrome: A Rare Case Report of a 11-Year-Old Child

    PubMed Central

    Tandon, Sandeep; Chauhan, Yashwant; Jain, Manish

    2016-01-01

    Gorlin-Goltz Syndrome, also known as nevoid basal cell carcinoma syndrome (NBCCS), is an autosomal dominant trait caused due to mutations in the patched tumor suppressor gene (PTCH) gene found on the long arm of chromosome 9. The syndrome is characterized by the presence of odontogenic keratocysts (OKCs), basal cell carcinomas, and skeletal malformations. Early diagnosis of the syndrome can be done by pedodontist as OKC is one of the early manifestations of the syndrome. Early diagnosis and treatment is important for long-term prognosis of the syndrome by reducing the severity of cutaneous carcinomas and deformities due to jaw cyst. The present case describes an 11-year-old patient with some typical features of NBCCS, which were diagnosed through its oral and maxillofacial manifestations. This case emphasizes the importance of pedodontist in early recognition of the syndrome. How to cite this article Tandon S, Chauhan Y, Sharma M, Jain M. Gorlin-Goltz Syndrome: A Rare Case Report of a 11-Year-Old Child. Int J Clin Pediatr Dent 2016;9(3):264-268. PMID:27843260

  8. Position of the American Dietetic Association: nutrition guidance for healthy children ages 2 to 11 years.

    PubMed

    Nicklas, Theresa A; Hayes, Dayle

    2008-06-01

    It is the position of the American Dietetic Association that children ages 2 to 11 years should achieve optimal physical and cognitive development, attain a healthy weight, enjoy food, and reduce the risk of chronic disease through appropriate eating habits and participation in regular physical activity. The health status of American children has generally improved during the past 3 decades. However, the number of children who are overweight has more than doubled among 2- to 5-year-old children and more than tripled among 6- to 11-year-old children, which has major health consequences. This increase in childhood overweight has broadened the focus of dietary guidance to address children's overconsumption of energy-dense, nutrient-poor foods and beverages and physical activity patterns. Health promotion will help reduce diet-related risks of chronic degenerative diseases, such as cardiovascular disease, type 2 diabetes, cancer, obesity, and osteoporosis. This position reviews what US children are eating and explores trends in food and nutrient intakes as well as the impact of school meals on children's diets. Dietary recommendations and guidelines and the benefits of physical activity are also discussed. The roles of parents and caregivers in influencing the development of healthful eating behaviors are highlighted. Specific recommendations and sources of nutrition messages to improve the nutritional well-being of children are provided for food and nutrition professionals

  9. Position of the American Dietetic Association: Dietary guidance for healthy children ages 2 to 11 years.

    PubMed

    Nicklas, Thersea; Johnson, Rachel

    2004-04-01

    It is the position of the American Dietetic Association that children ages 2 to 11 years should achieve optimal physical and cognitive development, attain a healthy weight, enjoy food, and reduce the risk of chronic disease through appropriate eating habits and participation in regular physical activity. The health status of American children has generally improved over the past three decades. However, the number of children who are overweight has more than doubled among 2- to 5-year-old children and more than tripled among 6- to 11-year-old children, which has major health consequences. This increase in childhood overweight has broadened the focus of dietary guidance to address children's over consumption of energy-dense, nutrient-poor foods and beverages and physical activity patterns. Health promotion will help reduce diet-related risks of chronic degenerative diseases, such as cardiovascular disease, type 2 diabetes, cancer, obesity, and osteoporosis. This position paper reviews what US children are eating and explores trends in food and nutrient intakes as well as the impact of school meals on children's diets. Dietary recommendations and guidelines and the benefits of physical activity are also discussed. The roles of parents and caregivers in influencing the development of healthy eating behaviors are highlighted. The American Dietetic Association works with other allied health and food industry professionals to translate dietary recommendations and guidelines into achievable, healthful messages. Specific recommendations to improve the nutritional well-being of children are provided for dietetics professionals, parents, and caregivers.

  10. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection.

    PubMed

    Ng, Oi-Wing; Chia, Adeline; Tan, Anthony T; Jadi, Ramesh S; Leong, Hoe Nam; Bertoletti, Antonio; Tan, Yee-Joo

    2016-04-12

    Severe acute respiratory syndrome (SARS) is a highly contagious infectious disease which first emerged in late 2002, caused by a then novel human coronavirus, SARS coronavirus (SARS-CoV). The virus is believed to have originated from bats and transmitted to human through intermediate animals such as civet cats. The re-emergence of SARS-CoV remains a valid concern due to the continual persistence of zoonotic SARS-CoVs and SARS-like CoVs (SL-CoVs) in bat reservoirs. In this study, the screening for the presence of SARS-specific T cells in a cohort of three SARS-recovered individuals at 9 and 11 years post-infection was carried out, and all memory T cell responses detected target the SARS-CoV structural proteins. Two CD8(+) T cell responses targeting the SARS-CoV membrane (M) and nucleocapsid (N) proteins were characterized by determining their HLA restriction and minimal T cell epitope regions. Furthermore, these responses were found to persist up to 11 years post-infection. An absence of cross-reactivity of these CD8(+) T cell responses against the newly-emerged Middle East respiratory syndrome coronavirus (MERS-CoV) was also demonstrated. The knowledge of the persistence of SARS-specific celullar immunity targeting the viral structural proteins in SARS-recovered individuals is important in the design and development of SARS vaccines, which are currently unavailable.

  11. Dose estimations for Iranian 11-year-old pediatric phantoms undergoing computed tomography examinations.

    PubMed

    Akhlaghi, Parisa; Miri-Hakimabad, Hashem; Rafat-Motavalli, Laleh

    2015-07-01

    In order to establish an organ and effective dose database for Iranian children undergoing computed tomography (CT) examinations, in the first step, two Iranian 11-year-old phantoms were constructed from image series obtained from CT and magnetic resonance imaging (MRI). Organ and effective doses for these phantoms were calculated for head, chest, abdomen-pelvis and chest-abdomen-pelvis (CAP) scans at tube voltages of 80, 100 and 120 kVp, and then they were compared with those of the University of Florida (UF) 11-year-old male phantom. Depth distributions of the organs and the mass of the surrounding tissues located in the beam path, which shield the internal organs, were determined for all phantoms. From the results, it was determined that the main organs of the UF phantom receive smaller doses than the two Iranian phantoms, except for the urinary bladder of the Iranian girl phantom. In addition, the relationship between the anatomical differences and the size of the dose delivered was also investigated and the discrepancies between the results were examined and justified.

  12. A case of dissociative fugue and general amnesia with an 11-year follow-up.

    PubMed

    Helmes, Edward; Brown, Julie-May; Elliott, Linda

    2015-01-01

    Dissociative fugue refers to loss of personal identity, often with the associated loss of memories of events (general amnesia). Here we report on the psychological assessment of a 54-year-old woman with loss of identity and memories of 33 years of her life attributed to dissociative fugue, along with a follow-up 11 years later. Significant levels of personal injury and stress preceded the onset of the amnesia. A detailed neuropsychological assessment was completed at a university psychology clinic, with a follow-up assessment there about 11 years later with an intent to determine whether changes in her cognitive status were associated with better recall of her life and with her emotional state. Psychomotor slowing and low scores on measures of attention and both verbal and visual memory were present initially, along with significant psychological distress associated with the diagnosis of posttraumatic stress disorder. Although memories of her life had not returned by follow-up, distress had abated and memory test scores had improved. The passage of time and a better emotional state did not lead to recovery of lost memories. Contrary to expectations, performance on tests of executive functions was good on both occasions. Multiple stressful events are attributed as having a role in maintaining the loss of memories.

  13. The Mars Gravity Field After 11 Years of Continuous Tracking Data from Mars Odyssey and MRO Missions

    NASA Astrophysics Data System (ADS)

    Genova, A.; Goossens, S.; Lemoine, F. G.; Mazarico, E.; Smith, D. E.; Zuber, M. T.

    2014-07-01

    The Mars Odyssey and MRO missions have provided more than 11 years of continuous tracking data of spacecraft in orbit. We will present the Mars static and seasonal gravity field from 11 years (2002-2012) of Mars Odyssey and MRO tracking data.

  14. Periodic (18.6-year) and cyclic (11-year) induced drought and flood in western North America

    NASA Astrophysics Data System (ADS)

    Currie, Robert Guinn

    1984-08-01

    Analysis of 102 reent tree-ring chronologies confirms earlier evidence for 18.6-year tidal drought/flood induction (Currie, 1981d, 1984b) and led to discovery of 11-year solar cycle induced drought/flood for western North America. Bistable phasing in terms of geography is found with epohs of maximum in lunar nodal 18.6-year drought in western Canada out of phase with those in the western United States and northern Mexico the past two centuries. Solar drought/flood induction provides one mechanism that appears to have modulated the intensity of nodal drought/flood induction in the latter region, most recently at epoch 1936.1. The above results were confirmed by analysis of yet more voluminous data, and they le to discovery of an example of bistable phasing with respect to time in western Canada during the 17th century. The implications for agriculture of such phenomena, which occur worldwide (Currie, 1984c), are surveyed.

  15. Element Pool Changes within a Scrub-Oak Ecosystem after 11 Years of Exposure to Elevated CO2

    PubMed Central

    Duval, Benjamin D.; Dijkstra, Paul; Drake, Bert G.; Johnson, Dale W.; Ketterer, Michael E.; Megonigal, J. Patrick; Hungate, Bruce A.

    2013-01-01

    The effects of elevated CO2 on ecosystem element stocks are equivocal, in part because cumulative effects of CO2 on element pools are difficult to detect. We conducted a complete above and belowground inventory of non-nitrogen macro- and micronutrient stocks in a subtropical woodland exposed to twice-ambient CO2 concentrations for 11 years. We analyzed a suite of nutrient elements and metals important for nutrient cycling in soils to a depth of ∼2 m, in leaves and stems of the dominant oaks, in fine and coarse roots, and in litter. In conjunction with large biomass stimulation, elevated CO2 increased oak stem stocks of Na, Mg, P, K, V, Zn and Mo, and the aboveground pool of K and S. Elevated CO2 increased root pools of most elements, except Zn. CO2-stimulation of plant Ca was larger than the decline in the extractable Ca pool in soils, whereas for other elements, increased plant uptake matched the decline in the extractable pool in soil. We conclude that elevated CO2 caused a net transfer of a subset of nutrients from soil to plants, suggesting that ecosystems with a positive plant growth response under high CO2 will likely cause mobilization of elements from soil pools to plant biomass. PMID:23717607

  16. Numerical simulation of propagation of the MHD waves in sunspots

    NASA Astrophysics Data System (ADS)

    Parchevsky, K.; Kosovichev, A.; Khomenko, E.; Olshevsky, V.; Collados, M.

    2010-11-01

    We present results of numerical 3D simulation of propagation of MHD waves in sunspots. We used two self consistent magnetohydrostatic background models of sunspots. There are two main differences between these models: (i) the topology of the magnetic field and (ii) dependence of the horizontal profile of the sound speed on depth. The model with convex shape of the magnetic field lines near the photosphere has non-zero horizorntal perturbations of the sound speed up to the depth of 7.5 Mm (deep model). In the model with concave shape of the magnetic field lines near the photosphere Δ c/c is close to zero everywhere below 2 Mm (shallow model). Strong Alfven wave is generated at the wave source location in the deep model. This wave is almost unnoticeable in the shallow model. Using filtering technique we separated magnetoacoustic and magnetogravity waves. It is shown, that inside the sunspot magnetoacoustic and magnetogravity waves are not spatially separated unlike the case of the horizontally uniform background model. The sunspot causes anisotropy of the amplitude distribution along the wavefront and changes the shape of the wavefront. The amplitude of the waves is reduced inside the sunspot. This effect is stronger for the magnetogravity waves than for magnetoacoustic waves. The shape of the wavefront of the magnetogravity waves is distorted stronger as well. The deep model causes bigger anisotropy for both mgnetoacoustic and magneto gravity waves than the shallow model.

  17. Recalibrating the Sunspot Number (SSN): The SSN Workshops

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.; Clette, F.; Svalgaard, L.

    The sunspot number (SSN) is the primary time series in solar and solar-terrestrial physics. Currently there are two widely-used sunspot numbers, the International SSN and the Group SSN, which differ significantly before ˜1885. Thus the SSN is potentially a free-parameter in models of climate change or solar dynamo behavior. To reconcile the International and Group SSNs, we have organized a series of workshops. The end goal of this effort is a community-vetted time series of sunspot numbers for use in long-term studies. We are about half way through the process, with the International and Group SSN time series reconciled back to 1826. We hope to have the reconciliation completed back to the beginning of the SSN time series (1610) by mid-2014. We have learned or relearned some interesting things along the way: (1) the International or Wolf SSN time series is not based solely on sunspots; (2) the simple formula from Wolf for the SSN that is found in all solar physics textbooks is not used in practice (all sunspots are not equal); and (3) the Group SSN appears to be too low before 1885. When completed, the reconciled ˜400-yr SSN time series will serve as a bridge to the millennia-scale record of solar variability from cosmogenic nuclide concentrations in tree rings and ice cores.

  18. LOOKING FOR GRANULATION AND PERIODICITY IMPRINTS IN THE SUNSPOT TIME SERIES

    SciTech Connect

    Lopes, Ilídio; Silva, Hugo G. E-mail: hgsilva@uevora.pt

    2015-05-10

    The sunspot activity is the end result of the cyclic destruction and regeneration of magnetic fields by the dynamo action. We propose a new method to analyze the daily sunspot areas data recorded since 1874. By computing the power spectral density of daily data series using the Mexican hat wavelet, we found a power spectrum with a well-defined shape, characterized by three features. The first term is the 22 yr solar magnetic cycle, estimated in our work to be 18.43 yr. The second term is related to the daily volatility of sunspots. This term is most likely produced by the turbulent motions linked to the solar granulation. The last term corresponds to a periodic source associated with the solar magnetic activity, for which the maximum power spectral density occurs at 22.67 days. This value is part of the 22–27 day periodicity region that shows an above-average intensity in the power spectra. The origin of this 22.67 day periodic process is not clearly identified, and there is a possibility that it can be produced by convective flows inside the star. The study clearly shows a north–south asymmetry. The 18.43 yr periodical source is correlated between the two hemispheres, but the 22.67 day one is not correlated. It is shown that toward the large timescales an excess occurs in the northern hemisphere, especially near the previous two periodic sources. To further investigate the 22.67 day periodicity, we made a Lomb–Scargle spectral analysis. The study suggests that this periodicity is distinct from others found nearby.

  19. Decadal variability of upper ocean heat content in the Pacific: Responding to the 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Wang, Gang; Yan, Shuangxi; Qiao, Fangli

    2015-12-01

    Ocean heat content anomaly (OHCa) time series in some areas of the Pacific are significantly correlated with the total solar irradiance (TSI). Using the composite mean-difference method, we determined the mean response of OHCa in the upper-700 m of the ocean to the TSI. Among the high solar response areas, we figure out two regions, one in the tropical mid-Pacific and the other in the western Pacific, where the OHCa present decadal variations, but different phases. The variation in phase of the solar response indicates that there exists an agency for the OHCa's response to TSI.

  20. Comments on: "11-year cycle in Schumann resonance data as observed in Antarctica" by Nickolaenko et al. (2015)

    NASA Astrophysics Data System (ADS)

    Williams, E.

    2016-03-01

    Recent interpretation by Nickolaenko et al. (2015) of Schumann resonance observations in Antarctica is reviewed. Evidence from the literature suggests that certain aspects of these interpretations are flawed. Alternative interpretations are offered.

  1. Changes of net primary productivity in China during recent 11 years detected using an ecological model driven by MODIS data

    NASA Astrophysics Data System (ADS)

    Liu, Yibo; Ju, Weimin; He, Honglin; Wang, Shaoqiang; Sun, Rui; Zhang, Yuandong

    2013-03-01

    Net primary productivity (NPP) is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study the process-based Boreal Ecosystem Productivity Simulator (BEPS) was employed to study the changes of NPP in China's ecosystems for the period from 2000 to 2010. The BEPS model was first validated using gross primary productivity (GPP) measured at typical flux sites and forest NPP measured at different regions. Then it was driven with leaf area index (LAI) inversed from the Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance and land cover products and meteorological data interpolated from observations at 753 national basic meteorological stations to simulate NPP at daily time steps and a spatial resolution of 500 m from January 1, 2000 to December 31, 2010. Validations show that BEPS is able to capture the seasonal variations of tower-based GPP and the spatial variability of forest NPP in different regions of China. Estimated national total of annual NPP varied from 2.63 to 2.84Pg C·yr-1, averaging 2.74 Pg C·yr-1 during the study period. Simulated terrestrial NPP shows spatial patterns decreasing from the east to the west and from the south to the north, in association with land cover types and climate. South-west China makes the largest contribution to the national total of NPP while NPP in the North-west account for only 3.97% of the national total. During the recent 11 years, the temporal changes of NPP were heterogamous. NPP increased in 63.8% of China's landmass, mainly in areas north of the Yangtze River and decreased in most areas of southern China, owing to the low temperature freezing in early 2008 and the severe drought in late 2009.

  2. Sunspot Number and Solar Radio Flux Prediction by Artificial Neural Network Method.

    NASA Astrophysics Data System (ADS)

    Ajabshirizadeh, Ali; Juzdani Nafiseh, Masoumzadeh

    Solar activity predictions improve our knowledge about solar magnetic field and are used by space weather operators to plan when to reboost satellites in low-Earth orbit, anticipate radiation exposure for current and upcoming missions and to plan for outage in radio-based communication and navigation systems. The level of solar activity is usually expressed by international sunspot number (Rz), showing the solar magnetic field activity and 10.7-cm solar radio flux index ( F10.7), preferred in space weather studies because of its higher signal-to-noise ratio and direct relationship to the solar EUV-UV emission. A large range of methods is used to predict the occurrence and amplitude of solar cycle. In this paper, we predict some solar indices (Rz, F10.7) in solar cycle 24 by using the neural network method.

  3. Sunspot Oscillations From The Chromosphere To The Corona

    NASA Astrophysics Data System (ADS)

    Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.

    The behavior of the 3 minute sunspot oscillations is studied as a function of temper- ature through the transition region using observations with CDS/SOHO and TRACE. The oscillations occur above the umbra, with amplitudes increasing to a maximum near 200 000 K, then decreasing towards higher temperatures. Deviations from pure linear oscillations are present in several cases. Power spectra of the oscillations are remarkably similar in the chromosphere and through the transition region in contra- diction to the predictions of the sunspot filter theory. The 3 minute oscillations pene- trate to the low temperature end of the corona, where they are channeled into smaller areas coinciding with the endpoints of sunspot coronal loops. This differs from the transition zone where the oscillating region covers the umbra.

  4. Detection of emerging sunspot regions in the solar interior.

    PubMed

    Ilonidis, Stathis; Zhao, Junwei; Kosovichev, Alexander

    2011-08-19

    Sunspots are regions where strong magnetic fields emerge from the solar interior and where major eruptive events occur. These energetic events can cause power outages, interrupt telecommunication and navigation services, and pose hazards to astronauts. We detected subsurface signatures of emerging sunspot regions before they appeared on the solar disc. Strong acoustic travel-time anomalies of an order of 12 to 16 seconds were detected as deep as 65,000 kilometers. These anomalies were associated with magnetic structures that emerged with an average speed of 0.3 to 0.6 kilometer per second and caused high peaks in the photospheric magnetic flux rate 1 to 2 days after the detection of the anomalies. Thus, synoptic imaging of subsurface magnetic activity may allow anticipation of large sunspot regions before they become visible, improving space weather forecast.

  5. Detection of Emerging Sunspot Regions in the Solar Interior

    NASA Astrophysics Data System (ADS)

    Ilonidis, Stathis; Zhao, Junwei; Kosovichev, Alexander

    2011-08-01

    Sunspots are regions where strong magnetic fields emerge from the solar interior and where major eruptive events occur. These energetic events can cause power outages, interrupt telecommunication and navigation services, and pose hazards to astronauts. We detected subsurface signatures of emerging sunspot regions before they appeared on the solar disc. Strong acoustic travel-time anomalies of an order of 12 to 16 seconds were detected as deep as 65,000 kilometers. These anomalies were associated with magnetic structures that emerged with an average speed of 0.3 to 0.6 kilometer per second and caused high peaks in the photospheric magnetic flux rate 1 to 2 days after the detection of the anomalies. Thus, synoptic imaging of subsurface magnetic activity may allow anticipation of large sunspot regions before they become visible, improving space weather forecast.

  6. A model for sunspot associated emission at 6 cm wavelength

    NASA Technical Reports Server (NTRS)

    Alissandrakis, C. E.; Kundu, M. R.; Lantos, P.

    1980-01-01

    Two-dimensional maps of total intensity and circular polarization of a sunspot region at 6 cm have been calculated using a simple model for the chromosphere-corona transition region and observations of the longitudinal component of the photospheric magnetic field. The calculations are in good agreement with the high resolution observations of the same sunspot region at 6 cm, obtained with the Westerbork Synthesis Radio Telescope. It is shown that the 6 cm radiation is predominantly due to gyroresonance absorption process at the second and third harmonics of the gyrofrequency (H = 900-600 G). Estimates of the conductive flux and the electron density in the transition region above the sunspot are also given.

  7. The Pioneer Venus Orbiter: 11 years of data. A laboratory for atmospheres seminar talk

    NASA Technical Reports Server (NTRS)

    Kasprzak, W. T.

    1990-01-01

    The Pioneer Venus Orbiter has been in operation since orbit insertion on December 4, 1978. For the past 11 years, it has been acquiring data in the salient features of the planet, its atmosphere, ionosphere, and interaction with the solar wind. A few of the results of this mission are summarized and their contribution to our general understanding of the planet Venus is discussed. Although Earth and Venus are often called twin planets, they are only superficially similar. Possessing no obvious evidence of plate tectonics, lacking water and an intrinsic magnetic field, and having a hot, dense carbon dioxide atmosphere with sulfuric acid clouds makes Venus a unique object of study by the Orbiter's instruments.

  8. Annular pancreas in an 11-year-old girl: a case report

    PubMed Central

    Moon, Suk-Bae

    2017-01-01

    Annular pancreas (AP) is a rare cause of congenital duodenal obstruction that is usually discovered at the neonatal period, but clinical severities can vary over a wide range and definite diagnosis could be delayed until late childhood or adulthood. We report here a case of AP detected in an 11-year-old girl who had a long history of symptoms of partial duodenal obstruction. Upper gastrointestinal (UGI) study revealed narrowed second portion of duodenum by extrinsic compression, and computed tomography demonstrated complete ring of pancreatic tissue surrounding the second portion of the duodenum. Diamond-shaped duodenoduodenostomy successfully cured the patient, and the postoperative UGI study showed smooth passage through the bypass segment. Although rare, AP should be differentiated in children with unresolved symptoms of partial duodenal obstruction. PMID:28280396

  9. Gorlin-Goltz Syndrome: A Rare Case Report of a 11-Year-Old Child.

    PubMed

    Tandon, Sandeep; Chauhan, Yashwant; Sharma, Meenakshi; Jain, Manish

    2016-01-01

    Gorlin-Goltz Syndrome, also known as nevoid basal cell carcinoma syndrome (NBCCS), is an autosomal dominant trait caused due to mutations in the patched tumor suppressor gene (PTCH) gene found on the long arm of chromosome 9. The syndrome is characterized by the presence of odontogenic keratocysts (OKCs), basal cell carcinomas, and skeletal malformations. Early diagnosis of the syndrome can be done by pedodontist as OKC is one of the early manifestations of the syndrome. Early diagnosis and treatment is important for long-term prognosis of the syndrome by reducing the severity of cutaneous carcinomas and deformities due to jaw cyst. The present case describes an 11-year-old patient with some typical features of NBCCS, which were diagnosed through its oral and maxillofacial manifestations. This case emphasizes the importance of pedodontist in early recognition of the syndrome.

  10. The 11 year history of starspots on V1149 Ori = HD 37824

    NASA Technical Reports Server (NTRS)

    Hall, Douglas S.; Fekel, Francis C.; Henry, Gregory W.; Barksdale, William S.

    1991-01-01

    All available radial-velocity measures, published and unpublished, yield an improved period and a new (assumed circular) solution. The period is 53.58 d +/- 0.02 d, and conjunction (K1 giant in front) was at 2 444 325.93 +/- 0.12 d. Eleven years of V-band photometry, published and unpublished, between 1978-1979 and 1989-1990 are analyzed. Eighteen data groups are fit with a two-spot light-curve-modeling technique. Six spots existing sometime during the 11 years are identified, and the 4-percent range of their rotation periods is used to estimate a differential rotation coefficient of k = 0.08 +/- 0.02. Observed lifetimes of those six spots are consistent with times calculated on the assumption that large spots are disrupted by the shear of differential rotation. The two best observed spots each lasted about five years.

  11. A fatal outcome of complicated severe diabetic ketoacidosis in a 11-year-old girl.

    PubMed

    Severinski, Srećko; Butorac Ahel, Ivona; Ovuka, Aleksandar; Verbić, Arijan

    2016-08-01

    Diabetic ketoacidosis (DKA) is a complex metabolic state characterized by hyperglycemia, metabolic acidosis and ketonuria. Cerebral edema is the most common rare complication of DKA in children. The objective of the study was to emphasize the importance of careful evaluation and monitoring for signs and symptoms of cerebral edema in all children undergoing treatment for DKA. We present a case of 11-year-old girl with a history of diabetes mellitus type I (T1DM) who presented with severe DKA complicated by hypovolemic shock, cerebral edema and hematemesis. Considering the fact that complications of DKA are rare and require a high index of clinical suspicion, early recognition and treatment are crucial for avoiding permanent damage.

  12. Music listening and cognitive abilities in 10- and 11-year-olds: the blur effect.

    PubMed

    Schellenberg, E Glenn; Hallam, Susan

    2005-12-01

    The spatial abilities of a large sample of 10 and 11 year olds were tested after they listened to contemporary pop music, music composed by Mozart, or a discussion about the present experiment. After being assigned at random to one of the three listening experiences, each child completed two tests of spatial abilities. Performance on one of the tests (square completion) did not differ as a function of the listening experience, but performance on the other test (paper folding) was superior for children who listened to popular music compared to the other two groups. These findings are consistent with the view that positive benefits of music listening on cognitive abilities are most likely to be evident when the music is enjoyed by the listener.

  13. Annular pancreas in an 11-year-old girl: a case report.

    PubMed

    Moon, Suk-Bae

    2017-01-01

    Annular pancreas (AP) is a rare cause of congenital duodenal obstruction that is usually discovered at the neonatal period, but clinical severities can vary over a wide range and definite diagnosis could be delayed until late childhood or adulthood. We report here a case of AP detected in an 11-year-old girl who had a long history of symptoms of partial duodenal obstruction. Upper gastrointestinal (UGI) study revealed narrowed second portion of duodenum by extrinsic compression, and computed tomography demonstrated complete ring of pancreatic tissue surrounding the second portion of the duodenum. Diamond-shaped duodenoduodenostomy successfully cured the patient, and the postoperative UGI study showed smooth passage through the bypass segment. Although rare, AP should be differentiated in children with unresolved symptoms of partial duodenal obstruction.

  14. An 11-year and 10-month-old girl with purpura and chest pain.

    PubMed

    Chen, Pei-Hsuan; Chiang, Bor-Luen; Lu, Meng-Yao; Yang, Yao-Hsu

    2014-10-01

    Mucosa-associated lymphoid tissue lymphoma (MALToma) is a type of B-cell lymphoma. Case reports of childhood thymic MALToma and its association with vasculitis are rarely found in the related literature. Herein, we present a report of an 11-year and 10-month-old girl who was initially diagnosed with cutaneous vasculitis characterized by nonthrombocytopenic palpable purpura, positive antinuclear antibody and anti-SSA (Ro) antibody. Eight months later, a thymic mediastinal mass was found. Surgical excision was performed and results of pathological analysis revealed an extranodal marginal zone CD20(+) B-cell MALToma. Benign response to the chemotherapeutic regimen of Berlin-Frankfurt-Münster group NHL-BFM 90 R2 without relapse was noted in 2 years of follow-up. For the first time, our case demonstrated some clinical evidence of the association between vasculitis and childhood MALToma.

  15. Recurrence of thymoma after 11 years presenting as diffuse pleural thickening.

    PubMed

    Köksal, Deniz; Bayiz, Hülya; Gülgösteren, Mahmut; Başay, Nihal; Mutluay, Neslihan; Boyacı, Ebru; Berktaş, Bahadır; Çakır, Ebru; Berkoğlu, Mine

    2012-01-01

    A 50-year-old man presented with a 1-month history of dyspnea, weight loss, and pleuritic chest pain. He had environmental asbest exposure from birth to 12 years-old. Past medical history revealed maximal thymectomy operation and adjuvant radiotherapy with the diagnosis of minimally invasive lymphocytic thymoma 11 years ago. Thorax computerized tomography demonstrated a circumferential pleural thickening encasing the entire left lung and pleural effusion. VATS-pleural biopsy revealed the diagnosis invasive tymoma, Type B1, stage IVA. In conclusion, the diagnosis of invasive thymoma must be kept in mind in the differential diagnosis of diffuse pleural lesions. The recurrence of thymomas may be as long as 10 years after complete resection.

  16. Hierarchical reproductive allocation and allometry within a perennial bunchgrass after 11 years of nutrient addition.

    PubMed

    Tian, Dashuan; Pan, Qingmin; Simmons, Matthew; Chaolu, Hada; Du, Baohong; Bai, Yongfei; Wang, Hong; Han, Xingguo

    2012-01-01

    Bunchgrasses are one of the most important plant functional groups in grassland ecosystems. Reproductive allocation (RA) for a bunchgrass is a hierarchical process; however, how bunchgrasses adjust their RAs along hierarchical levels in response to nutrient addition has never been addressed. Here, utilizing an 11-year nutrient addition experiment, we examined the patterns and variations in RA of Agropyron cristatum at the individual, tiller and spike levels. We evaluated the reproductive allometric relationship at each level by type II regression analysis to determine size-dependent and size-independent effects on plant RA variations. Our results indicate that the proportion of reproductive individuals in A. cristatum increased significantly after 11 years of nutrient addition. Adjustments in RA in A. cristatum were mainly occurred at the individual and tiller levels but not at the spike level. A size-dependent effect was a dominant mechanism underlying the changes in plant RA at both individual and tiller levels. Likewise, the distribution of plant size was markedly changed with large individuals increasing after nutrient addition. Tiller-level RA may be a limiting factor for the adjustment of RA in A. cristatum. To the best of our knowledge, this study is the first to examine plant responses in terms of reproductive allocation and allometry to nutrient enrichment within a bunchgrass population from a hierarchical view. Our findings have important implications for understanding the mechanisms underlying bunchgrass responses in RA to future eutrophication due to human activities. In addition, we developed a hierarchical analysis method for disentangling the mechanisms that lead to variation in RA for perennial bunchgrasses.

  17. Hierarchical Reproductive Allocation and Allometry within a Perennial Bunchgrass after 11 Years of Nutrient Addition

    PubMed Central

    Tian, Dashuan; Pan, Qingmin; Simmons, Matthew; Chaolu, Hada; Du, Baohong; Bai, Yongfei; Wang, Hong; Han, Xingguo

    2012-01-01

    Bunchgrasses are one of the most important plant functional groups in grassland ecosystems. Reproductive allocation (RA) for a bunchgrass is a hierarchical process; however, how bunchgrasses adjust their RAs along hierarchical levels in response to nutrient addition has never been addressed. Here, utilizing an 11-year nutrient addition experiment, we examined the patterns and variations in RA of Agropyron cristatum at the individual, tiller and spike levels. We evaluated the reproductive allometric relationship at each level by type II regression analysis to determine size-dependent and size-independent effects on plant RA variations. Our results indicate that the proportion of reproductive individuals in A. cristatum increased significantly after 11 years of nutrient addition. Adjustments in RA in A. cristatum were mainly occurred at the individual and tiller levels but not at the spike level. A size-dependent effect was a dominant mechanism underlying the changes in plant RA at both individual and tiller levels. Likewise, the distribution of plant size was markedly changed with large individuals increasing after nutrient addition. Tiller-level RA may be a limiting factor for the adjustment of RA in A. cristatum. To the best of our knowledge, this study is the first to examine plant responses in terms of reproductive allocation and allometry to nutrient enrichment within a bunchgrass population from a hierarchical view. Our findings have important implications for understanding the mechanisms underlying bunchgrass responses in RA to future eutrophication due to human activities. In addition, we developed a hierarchical analysis method for disentangling the mechanisms that lead to variation in RA for perennial bunchgrasses. PMID:22984408

  18. A solar eruption driven by rapid sunspot rotation

    SciTech Connect

    Ruan, Guiping; Chen, Yao; Du, Guohui; Wang, Shuo; Jing, Ju; Wang, Haimin; Zhang, Hongqi; Su, Jiangtao; Xu, Haiqing; Li, Gang; Li, Xing

    2014-04-01

    We present the observation of a major solar eruption that is associated with fast sunspot rotation. The event includes a sigmoidal filament eruption, a coronal mass ejection, and a GOES X2.1 flare from NOAA active region 11283. The filament and some overlying arcades were partially rooted in a sunspot. The sunspot rotated at ∼10° hr{sup –1} during a period of 6 hr prior to the eruption. In this period, the filament was found to rise gradually along with the sunspot rotation. Based on the Helioseismic and Magnetic Imager observation, for an area along the polarity inversion line underneath the filament, we found gradual pre-eruption decreases of both the mean strength of the photospheric horizontal field (B{sub h} ) and the mean inclination angle between the vector magnetic field and the local radial (or vertical) direction. These observations are consistent with the pre-eruption gradual rising of the filament-associated magnetic structure. In addition, according to the nonlinear force-free field reconstruction of the coronal magnetic field, a pre-eruption magnetic flux rope structure is found to be in alignment with the filament, and a considerable amount of magnetic energy was transported to the corona during the period of sunspot rotation. Our study provides evidence that in this event sunspot rotation plays an important role in twisting, energizing, and destabilizing the coronal filament-flux rope system, and led to the eruption. We also propose that the pre-event evolution of B{sub h} may be used to discern the driving mechanism of eruptions.

  19. Imaging Spectroscopy of a Sunspot: Thermal and Velocity Structure

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.

    2002-08-01

    The purpose of this paper is (1) to confirm and establish the working of a dual-etalon Fabry-Pérot imaging spectroscopy system at the National Solar Observatory/Sacramento Peak Dunn Solar Telescope and (2) to use this system to extend previous work by many authors and understand the structure and dynamics of sunspots. A detailed investigation of the thermal and velocity structure in an isolated sunspot, using the Fe I 5576 Å spectral line, is presented. The concept of flowless maps is incorporated, to separate velocity and intensity effects. The resulting intensities are used to generate thermal maps of the sunspot along the height of formation of a spectral line, followed by a thermal span map. The thermal span in penumbral regions is in the range of 1350-1580 K. It is a factor of 2 smaller in the umbra. Using spectral line bisectors, we extend the concept of a velocity span to a sunspot, following Gray. The velocity span is used to study the velocity gradients across a sunspot. The velocity span maximizes in the middle of the sunspot penumbra and falls off on either side. The Doppler-neutralized mean bisectors from the disk-side and limb-side penumbra show more sharply inclined gradients, when compared with the C-shaped photospheric bisectors. The mean umbral bisectors show sharp, <-shaped profiles. In most of the penumbra, the individual bisectors are sharply inclined, with a shape of ``/'' or ``\\,'' indicative of a highly suppressed convective flow. The intensity and velocity data show that a new family of penumbral filaments rises in the middle penumbra. Bisector intensity-velocity relationships display opposite gradients in the inner and outer penumbra, showing the rising and falling parts of curved penumbral flux tubes. Some clustering of the bisector intensity-velocity relationship is perhaps due to the fluted nature of flux tubes.

  20. SYSTEMATIC REGULARITY OF HEMISPHERIC SUNSPOT AREAS OVER THE PAST 140 YEARS

    SciTech Connect

    Deng, L. H.; Xiang, Y. Y.; Qu, Z. N.; An, J. M.

    2016-03-15

    Solar magnetic activity varies with time in the two hemispheres in different ways. The hemispheric interconnection of solar activity phenomena provides an important clue to understanding the dynamical behavior of solar dynamo actions. In this paper, several analysis approaches are proposed to analyze the systematic regularity of hemispheric asynchronism and amplitude asymmetry of long-term sunspot areas during solar cycles 9–24. It is found that, (1) both the hemispheric asynchronism and the amplitude asymmetry of sunspot areas are prevalent behaviors and are not anomalous, but the hemispheric asynchronism exhibits a much more regular behavior than the amplitude asymmetry; (2) the phase-leading hemisphere returns back to the identical hemisphere every 8 solar cycles, and the secular periodic pattern of hemispheric phase differences follows 3 (south leading) + 5 (north leading) solar cycles, which probably corresponds to the Gleissberg cycle; and (3) the pronounced periodicities of (absolute and normalized) asymmetry indices and lines of synchronization (LOSs) are not identical: the significant periodic oscillations are 80.65 ± 6.31, 20.91 ± 0.40, and 13.45 ± 0.16 years for the LOS values, and 51.34 ± 2.48, 8.83/8.69 ± 0.07, and 3.77 ± 0.02 years for the (absolute and normalized) asymmetry indices. The analysis results improve our knowledge on the hemispheric interrelation of solar magnetic activity and may provide valuable constraints for solar dynamo models.

  1. 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.

  2. Anomalous polarization profiles in sunspots: possible origin of umbral flashes

    PubMed

    Socas-Navarro; Trujillo Bueno J; Ruiz Cobo B

    2000-05-26

    We present time-series spectropolarimetric observations of sunspots in the Ca II infrared triplet lines, which show a periodic occurrence of anomalous, asymmetric, circular polarization profiles in the umbral chromosphere. The profiles may be caused by the periodic development of an unresolved atmospheric component in a downward flowing magnetized environment. This active component with upward directed velocities as high as 10 kilometers per second is connected to the umbral flash (UF) phenomenon. We can explain the observations with a semiempirical model of the chromospheric oscillation and of the sunspot magnetized atmospheric plasma during a UF event.

  3. Gauging the Nearness and Size of Cycle Maximum

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2003-01-01

    A simple method for monitoring the nearness and size of conventional cycle maximum for an ongoing sunspot cycle is examined. The method uses the observed maximum daily value and the maximum monthly mean value of international sunspot number and the maximum value of the 2-mo moving average of monthly mean sunspot number to effect the estimation. For cycle 23, a maximum daily value of 246, a maximum monthly mean of 170.1, and a maximum 2-mo moving average of 148.9 were each observed in July 2000. Taken together, these values strongly suggest that conventional maximum amplitude for cycle 23 would be approx. 124.5, occurring near July 2002 +/-5 mo, very close to the now well-established conventional maximum amplitude and occurrence date for cycle 23-120.8 in April 2000.

  4. Is there long-range memory in solar activity on timescales shorter than the sunspot period?

    NASA Astrophysics Data System (ADS)

    Rypdal, M.; Rypdal, K.

    2012-04-01

    The sunspot number (SSN), the total solar irradiance (TSI), a TSI reconstruction, and the solar flare index (SFI) are analyzed for long-range persistence (LRP). Standard Hurst analysis yields H ≈ 0.9, which suggests strong LRP. However, solar activity time series are nonstationary because of the almost-periodic 11 year smooth component, and the analysis does not give the correct H for the stochastic component. Better estimates are obtained by detrended fluctuation analysis, but estimates are biased and errors are large because of the short time records. These time series can be modeled as a stochastic process of the form x(t) = y(t) + σy(t)wH(t), where y(t) is the smooth component and wH(t) is a stationary fractional noise with Hurst exponent H. From ensembles of numerical solutions to the stochastic model and application of Bayes' theorem, we can obtain bias and error bars on H and also a test of the hypothesis that a process is uncorrelated (H = 1/2). The conclusions from the present data sets are that SSN, TSI, and TSI reconstruction almost certainly are long-range persistent, but with the most probable value H ≈ 0.7. The SFI process, however, is either very weakly persistent (H < 0.6) or completely uncorrelated on timescales longer than a few solar rotations. Differences between stochastic properties of the TSI and its reconstruction indicate some error in the reconstruction scheme.

  5. The nature of the sunspot phenomenon. I - Solutions of the heat transport equation

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1974-01-01

    It is pointed out that sunspots represent a disruption in the uniform flow of heat through the convective zone. The basic sunspot structure is, therefore, determined by the energy transport equation. The solutions of this equation for the case of stochastic heat transport are examined. It is concluded that a sunspot is basically a region of enhanced, rather than inhibited, energy transport and emissivity. The heat flow equations are discussed and attention is given to the shallow depth of the sunspot phenomenon. The sunspot is seen as a heat engine of high efficiency which converts most of the heat flux into hydromagnetic waves.

  6. Creating a sunspot database at the Solar Observatory of Ica National University in Perú

    NASA Astrophysics Data System (ADS)

    Martínez-Meneses, Lurdes

    2012-07-01

    We describe the database and the method used to analyze the sunspot data recorded at the Solar Observatory of the University of Ica in Peru. The parameters that are measured include the relative sunspot number (R), the sunspot area, their positions on the disk, and an estimate of the constant (k) included in R. Sunspots in the database are classified following the Zurich Classification System. From these observations, the active region area, the sunspot rotation speed, and other active regions properties can be estimated.

  7. The Shape of Solar Cycles Described by a Simplified Binary Mixture of Gaussian Functions

    NASA Astrophysics Data System (ADS)

    Li, F. Y.; Xiang, N. B.; Kong, D. F.; Xie, J. L.

    2017-01-01

    Sunspot cycles usually present a double-peak structure. This work is devoted to using a function to describe the shape of sunspot cycles, including bimodal cycles, and we find that the shape of sunspot cycles can be described by a binary mixture of Gaussian functions with six parameters, two amplitudes, two gradients of curve, and two rising times, and the parameters could be reduced to three. The fitting result of this binary mixture of Gaussian functions is compared with some other functions used previously in the literature, and this function works pretty well, especially at cycle peaks. It is worth mentioning that the function can describe well the shape of those sunspot cycles that show double peaks, and it is superior to the binary mixture of the Laplace functions that was once utilized. The Solar Influences Data Analysis Center, on behalf of the World Data Center, recently issued a new version (version 2) of sunspot number. The characteristics of sunspot cycles are investigated, based on the function description of the new version.

  8. VizieR Online Data Catalog: Scheiner drawing sunspot areas and tilt angles (Arlt+, 2016)

    NASA Astrophysics Data System (ADS)

    Arlt, R.; Senthamizh Pavai, V.; Schmiel, C.; Spada, F.

    2016-09-01

    Christoph Scheiner and his collaborators observed the sunspots from 1611-1631 at five different locations of Rome in Italy, Ingolstadt in Germany, Douai (Duacum in Latin) in France, Freiburg im Breisgau, Germany and Vienna, Austria. However, most of his published drawings were made in Rome. These sunspot drawings are important because they can tell us how the solar activity declined to a very low-activity phase which lasted for nearly five decades. The three sources used for the sunspot data extraction are Scheiner (1630rour.book.....S, Rosa Ursina sive solis), Scheiner (1651ppsm.book.....S, Prodromus pro sole mobili et terra stabili contra Academicum Florentinum Galilaeum a Galilaeis), and Reeves & Van Helden (2010, On sunspots. Galileo Galilei and Christoph Scheiner (University of Chicago Press)). The suspot drawings show the sunspot groups traversing the solar disk in a single full-disk drawing. The positions and areas of the sunspots were measured using 13 circular cursor shapes with different diameters. Umbral areas for 8167 sunspots and tilt angles for 697 manually selected, supposedly bipolar groups were obtained from Scheiner's sunspot drawings. The database does not contain spotless days. There is, of course, no polarity information in the sunspot drawings, so the tilt angles are actually pseudo-tilt angles. Both an updated sunspot database and a tilt angle database may be available at http://www.aip.de/Members/rarlt/sunspots for further study. (2 data files).

  9. Helioseismic Holography of Simulated Sunspots: Magnetic and Thermal Contributions to Travel Times

    NASA Astrophysics Data System (ADS)

    Felipe, T.; Braun, D. C.; Crouch, A. D.; Birch, A. C.

    2016-10-01

    Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure.

  10. VizieR Online Data Catalog: Sunspot areas and tilt angles (Senthamizh Pavai+, 2015)

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    We present sunspot positions and areas from historical observations of sunspots by Samuel Heinrich Schwabe from Dessau, Germany. He has recorded his observations of sunspots from 1825-1867 as drawings in small circles of about 5cm diameter (representing the solar disk). Even though he has used quite a number of telescopes for his observations, the majority of the full-disk drawings were made with a 3-1/2-foot telescope from Fraunhofer. His observing log books are stored in the library of the Royal Astronomical Society in London. Those drawings were digitized photographically with a resolution of 2912x4378 pixels per page. The sizes and positions of the sunspots were measured using a dozen of circular mouse cursor shapes with different diameters. 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. 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 (two or more spots). There is, of course, no polarity information in the observations. Both an updated sunspot database and a tilt angle database are available at http://www.aip.de/Members/rarlt/ sunspots for further study. (2 data files).

  11. 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.

  12. Scrub-Oak Biomass Stimulation by CO2 Enrichment: Sustained 11 Years But Mediated by Precipitation and Contrasting Species Responses

    NASA Astrophysics Data System (ADS)

    Seiler, T.; Li, J.; Dijkstra, P.; Anderson, H.; Johnson, D.; Hinkle, R.; Drake, B.

    2007-12-01

    Terrestrial ecosystems may mitigate rising atmospheric carbon dioxide concentration (CO2) through increased carbon uptake and sequestration in plant biomass. Elevated CO2 commonly produces initial stimulation of photosynthesis and growth, but due primarily to complex interactions with climate related factors (i.e. water, light and nutrients), uncertainty regarding long-term biomass response persists. After 11 years of CO2 enrichment (ambient and ambient + 350 ppm) using open-top chambers, aboveground biomass stimulation was sustained in a Florida scrub-oak ecosystem, yielding a 67% increase at final harvest in June 2007. The scrub oaks Quercus geminata and Quercus myrtifolia represented 85% of total ecosystem aboveground biomass but displayed contrasting responses to elevated CO2. Q. myrtifolia showed consistent increase in shoot biomass over the course of the study (128% stimulation by elevated CO2) while shoot biomass of Q. geminata was not significantly increased (+6% difference between treatments). Both species displayed long-term mean stimulation of net leaf photosynthesis to elevated CO2 under saturated light conditions: stimulation of photosynthesis in Q. myrtifolia was nearly twice that in Q. geminata (63% and 35%, respectively). Over the course of the study, Q. geminata consistently displayed photosynthetic acclimation via reductions in maximum carboxylation rate (Vcmax) and maximum rate of electron transport (Jmax) while Q. myrtifolia photosynthesis did not acclimate to elevated CO2. Inter-annual variation in Q. myrtifolia annual biomass increment was correlated with rainfall and elevated CO2 stimulation of absolute biomass accumulation was greatest in wet years. This effect was muted at the ecosystem level because CO2 stimulation of biomass in Q. geminata, which utilizes the water table to a greater extent than Q. myrtifolia, showed no relationship with rainfall. These advantages afforded to Q. myrtifolia by elevated CO2 produced a significant change in

  13. Coronal and chromospheric physics. [Sun, sunspots, and solar limb

    NASA Technical Reports Server (NTRS)

    Hall, D. N. B.; Landman, D. A.; Orrall, F. Q.

    1984-01-01

    The Solar Maximum Mission support program is mentioned along with investigations of the solar corona, prominences, and chromosphere. The solar limb was studied using far infrared and submillimeter photometry. Stokes profiles obtained from sunspot observations were examined with a polarimetric technique.

  14. Basic Information Processing Abilities at 11 years Account for Deficits in IQ Associated with Preterm Birth.

    PubMed

    Rose, Susan A; Feldman, Judith F; Jankowski, Jeffery J; Van Rossem, Ronan

    2011-07-01

    Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ. The performance of 11-year-old children born preterm (birth weight <1750g) and their full-term controls were compared on a large battery of 15 tasks, covering four basic cognitive domains -- memory, attention, speed of processing and representational competence. The validity of these four domains was established using latent variables and confirmatory factor analysis (CFA). Preterms showed pervasive deficits within and across domains. Additionally, preterm deficits in IQ were completely mediated by these four cognitive domains in a structural equation model involving a cascade from elementary abilities (attention and speed), to more complex abilities (memory and representational competence), to IQ. The similarity of findings to those obtained with this cohort in infancy and toddlerhood suggest that preterm deficits persist - across time, across task, and from the non-verbal to the verbal period.

  15. Upward movement of plutonium to surface sediments during an 11-year field study.

    PubMed

    Kaplan, D I; Demirkanli, D I; Molz, F J; Beals, D M; Cadieux, J R; Halverson, J E

    2010-05-01

    An 11-year lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The (240)Pu/(239)Pu and (242)Pu/(239)Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments.

  16. Birth weight and cognitive function at age 11 years: the Scottish Mental Survey 1932

    PubMed Central

    Shenkin, S; Starr, J; Pattie, A; Rush, M; Whalley, L; Deary, I; PHARAOH, E. P.

    2001-01-01

    AIMS—To examine the relation between birth weight and cognitive function at age 11 years, and to examine whether this relation is independent of social class.
METHODS—Retrospective cohort study based on birth records from 1921 and cognitive function measured while at school at age 11 in 1932.Subjects were 985 live singletons born in the Edinburgh Royal Maternity and Simpson Memorial Hospital in 1921. Moray House Test scores from the Scottish Mental Survey 1932 were traced on 449of these children.
RESULTS—Mean score on Moray House Test increased from 30.6 at a birth weight of <2500 g to 44.7 at 4001-4500 g, after correcting for gestational age, maternal age, parity, social class, and legitimacy of birth. Multiple regression showed that 15.6% of the variance in Moray House Test score is contributed by a combination of social class (6.6%), birth weight (3.8%), child's exact age (2.4%), maternal parity (2.0%), and illegitimacy (1.5%). Structural equation modelling confirmed the independent contribution from each of these variables in predicting cognitive ability. A model in which birth weight acted as a mediator of social class had poor fit statistics.
CONCLUSION—In this 1921 birth cohort, social class and birth weight have independent effects on cognitive function at age 11. Future research will relate these childhood data to health and cognition in old age.

 PMID:11517097

  17. Microbiological monitoring of air quality in a university canteen: an 11-year report.

    PubMed

    Osimani, A; Aquilanti, L; Tavoletti, S; Clementi, F

    2013-06-01

    Over the past decade, an increased tendency to consume meals at dining facilities outside the home has been highlighted; moreover, meals supplied in food businesses have been involved in many foodborne disease outbreaks. Therefore, microbial air contamination in food processing facilities could be a concern and an increase of microbial loads could represent a risk factor, especially for the potential contamination of foods due to undesirable spoiling and pathogenic bacteria. In this paper, the results of an 11-year microbiological monitoring of air quality in a university canteen are reported. The study, which started in the year 2000, was performed within a hazard analysis and critical control point (HACCP) plan implementation of a canteen that produces about 1,000 meals a day in order to verify the effectiveness of corrective actions on the indoor air quality. The primary food preparation room, the kitchen, and three cold rooms underwent air sampling by using a calibrated impaction sampler. Our investigation detected a general and progressive improvement in the air quality of the canteen since the beginning of the study, thus suggesting the appropriateness of the corrective action undertaken during the HACCP implementation program.

  18. Prenatal Cocaine Exposure Alters Cortisol Stress Reactivity in 11 Year Old Children

    PubMed Central

    Lester, Barry M.; LaGasse, Linda L.; Shankaran, Seetha; Bada, Henrietta S.; Bauer, Charles R.; Lin, Richard; Das, Abhik; Higgins, Rosemary

    2011-01-01

    Objective Determine the association between prenatal cocaine exposure and postnatal environmental adversity on salivary cortisol stress reactivity in school aged children. Study design Subjects included 743 11 year old children (n=320 cocaine exposed; 423 comparison) followed since birth in a longitudinal prospective multisite study. Saliva samples were collected to measure cortisol at baseline and after a standardized procedure to induce psychological stress. Children were divided into those who showed an increase in cortisol from baseline to post stress and those who showed a decrease or blunted cortisol response. Covariates measured included site, birthweight, maternal pre and postnatal use of alcohol, tobacco or marijuana, social class, changes in caretakers, maternal depression and psychological symptoms, domestic and community violence, child abuse and quality of the home. Results With adjustment for confounding variables, cortisol reactivity to stress was more likely to be blunted in children with prenatal cocaine exposure. Cocaine exposed children exposed to domestic violence showed the strongest effects. Conclusion The combination of prenatal cocaine exposure and an adverse postnatal environment could down regulate the hypothalamic-pituitary-adrenal axis (HPA) resulting in the blunted cortisol response to stress possibly increasing risk for later psychopathology and adult disease. PMID:20400094

  19. A Comparison of Wolf's Reconstructed Record of Annual Sunspot Number with Schwabe's Observed Record of 'Clusters of Spots' for the Interval of 1826-1868

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1997-01-01

    On the basis of a comparison of Wolf s reconstructed record of yearly averages of sunspot number against Schwabe's observations of yearly counts of 'clusters of spots' (i.e., the yearly number of newly appearing sunspot groups) during the interval of 1826-1868, one infers that Wolf probably misplaced and underestimated the maximum amplitude for cycle 7. In particular, Schwabe's data suggest that the maximum amplitude for cycle 7 occurred in 1828 rather than in 1830 and that it measured about 86.3 (+/-13.9; i.e., the 90% confidence level) rather than 70.4. If true, then, the ascent and descent durations for cycle 7 should be 5 years each instead of 7 and 3 years, respectively. Likewise, on the basis of the same comparison, one infers that the maximums for cycles 8 and 9, occurring, respectively, in 1837 and 1848, were of comparable size (approximately 130), although, quite possibly, the one for cycle 8 may have been smaller. Lastly, presuming the continued action of the 'odd-even' effect (i.e., the odd-numbered following cycle of Hale even-odd cycle pairs having a maximum amplitude that is of comparable or larger size than the even-numbered leading cycle) during the earlier pre-modem era of cycles 6-9, one infers that Wolf's estimate for the size of cycle 6 probably is too low.

  20. Anticipating Cycle 24 Minimum and Its Consequences

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2007-01-01

    On the basis of the 12-mo moving average of monthly mean sunspot number (R) through November 2006, cycle 23 has persisted for 126 mo, having had a minimum of 8.0 in May 1996, a peak of 120.8 in April 2000, and an ascent duration of 47 mo. In November 2006, the 12-mo moving average of monthly mean sunspot number was 12.7, a value just outside the upper observed envelope of sunspot minimum values for the most recent cycles 16-23 (range 3.4-12.3), but within the 90-percent prediction interval (7.8 +/- 6.7). The first spotless day during the decline of cycle 23 occurred in January 2004, and the first occurrence of 10 or more and 20 or more spotless days was February 2006 and April 2007, respectively, inferring that sunspot minimum for cycle 24 is imminent. Through May 2007, 121 spotless days have accumulated. In terms of the weighted mean latitude (weighed by spot area) (LAT) and the highest observed latitude spot (HLS) in November 2006, 12-mo moving averages of these parameters measured 7.9 and 14.6 deg, respectively, these values being the lowest values yet observed during the decline of cycle 23 and being below corresponding mean values found for cycles 16-23. As yet, no high-latitude new-cycle spots have been seen nor has there been an upturn in LAT and HLS, these conditions having always preceded new cycle minimum by several months for past cycles. Together, these findings suggest that cycle 24 s minimum amplitude still lies well beyond November 2006. This implies that cycle 23 s period either will lie in the period "gap" (127-134 mo), a first for a sunspot cycle, or it will be longer than 134 mo, thus making cycle 23 a long-period cycle (like cycle 20) and indicating that cycle 24 s minimum will occur after July 2007. Should cycle 23 prove to be a cycle of longer period, a consequence might be that the maximum amplitude for cycle 24 may be smaller than previously predicted.

  1. Climate changes and solar cycles recorded at the Holocene Paraná Delta, and their impact on human population

    PubMed Central

    Milana, Juan Pablo; Kröhling, Daniela

    2015-01-01

    The Paraná delta, growing at a rate of c. 2 km2 yr−1 since 6,000 yrs, is one of the most complete records of the Late Holocene in southern South America. The evolution of this 17,400 km2 delta enclosed in Plata estuary, can be tracked by a series of 343 successive coastal-ridges showing a c.11 years period, in coincidence with sunspot cycle, also found in some North Hemisphere coastal-ridge successions. The Paraná delta shifted from fluvial, to wave-dominated, and back to the present fluvial-dominated delta, in response to climate changes associated with wind activity correlating with South American glacial cycles. The wave-dominated windy period coincides with the activation of the Pampean Sand Sea, suggesting desert conditions prevailed on the Pampas between 5,300 and 1,700 yrs, in coincidence with scarce or absent pre-historic aborigine remains (“archeological silence”). Further warmer and less windy conditions allowed human repopulation. Results suggest that aside the solar forcing, both short and medium term climate changes controlled delta evolution. An important learning is that a slight cooling would turn the highly productive pampas, into that unproductive desert and, given the lack of artificial irrigation systems, changing present-day warmhouse into a cooling cycle might be economically catastrophic for the region. PMID:26246410

  2. Climate changes and solar cycles recorded at the Holocene Paraná Delta, and their impact on human population

    NASA Astrophysics Data System (ADS)

    Milana, Juan Pablo; Kröhling, Daniela

    2015-08-01

    The Paraná delta, growing at a rate of c. 2 km2 yr-1 since 6,000 yrs, is one of the most complete records of the Late Holocene in southern South America. The evolution of this 17,400 km2 delta enclosed in Plata estuary, can be tracked by a series of 343 successive coastal-ridges showing a c.11 years period, in coincidence with sunspot cycle, also found in some North Hemisphere coastal-ridge successions. The Paraná delta shifted from fluvial, to wave-dominated, and back to the present fluvial-dominated delta, in response to climate changes associated with wind activity correlating with South American glacial cycles. The wave-dominated windy period coincides with the activation of the Pampean Sand Sea, suggesting desert conditions prevailed on the Pampas between 5,300 and 1,700 yrs, in coincidence with scarce or absent pre-historic aborigine remains (“archeological silence”). Further warmer and less windy conditions allowed human repopulation. Results suggest that aside the solar forcing, both short and medium term climate changes controlled delta evolution. An important learning is that a slight cooling would turn the highly productive pampas, into that unproductive desert and, given the lack of artificial irrigation systems, changing present-day warmhouse into a cooling cycle might be economically catastrophic for the region.

  3. Climate changes and solar cycles recorded at the Holocene Paraná Delta, and their impact on human population.

    PubMed

    Milana, Juan Pablo; Kröhling, Daniela

    2015-08-06

    The Paraná delta, growing at a rate of c. 2 km(2) yr(-1) since 6,000 yrs, is one of the most complete records of the Late Holocene in southern South America. The evolution of this 17,400 km(2) delta enclosed in Plata estuary, can be tracked by a series of 343 successive coastal-ridges showing a c.11 years period, in coincidence with sunspot cycle, also found in some North Hemisphere coastal-ridge successions. The Paraná delta shifted from fluvial, to wave-dominated, and back to the present fluvial-dominated delta, in response to climate changes associated with wind activity correlating with South American glacial cycles. The wave-dominated windy period coincides with the activation of the Pampean Sand Sea, suggesting desert conditions prevailed on the Pampas between 5,300 and 1,700 yrs, in coincidence with scarce or absent pre-historic aborigine remains ("archeological silence"). Further warmer and less windy conditions allowed human repopulation. Results suggest that aside the solar forcing, both short and medium term climate changes controlled delta evolution. An important learning is that a slight cooling would turn the highly productive pampas, into that unproductive desert and, given the lack of artificial irrigation systems, changing present-day warmhouse into a cooling cycle might be economically catastrophic for the region.

  4. Association between obesity and asthma in 4-11 year old children in the UK

    PubMed Central

    Figueroa-Munoz, J; Chinn, S; Rona, R

    2001-01-01

    BACKGROUND—There is evidence of a positive association between asthma and obesity in adults and in children. We investigated, in a large sample of English and Scottish primary school children, whether there is a consistent association between fatness and asthma symptoms in Britain.
METHODS—A cross sectional analysis was made of 18 218 children aged 4-11 years who participated in the 1993 or 1994 surveys of the National Study of Health and Growth (NSHG). Children belonged either to English or Scottish representative samples, or an English inner city sample. Asthma attacks in the previous year, occasional wheeze, or persistent wheeze were the symptoms used in the analysis. Body mass index (BMI) and the sum of triceps and subscapular skinfolds converted to standard deviation scores (SDS) were used to assess levels of fatness.
RESULTS—A total of 14 908 children (81.8%) were included in the analysis. In the multiple logistic analysis BMI and asthma (asthma attacks or wheeze) were associated in the representative sample (OR for the comparison of the 10th and 90th centiles of BMI 1.28,95% CI 1.11 to 1.48), but sum of skinfolds was unrelated to asthma symptoms in most analyses. The association between asthma and BMI was stronger in girls than in boys in the inner city sample, but less convincingly in the representative sample.
CONCLUSIONS—Levels of obesity are associated with asthma symptoms regardless of ethnicity. The association is more consistent for BMI than for sum of skinfolds, partly because obese children are more advanced in their maturation than other children. There is some evidence that, as in adults, the association is stronger in girls than in boys, but only in the multiethnic inner city sample.

 PMID:11209102

  5. Impact of Clinical Pharmacist on the Pediatric Intensive Care Practice: An 11-Year Tertiary Center Experience

    PubMed Central

    Crabtree, Heidi M.; Fryer, Karen R.; Graner, Kevin K.; Arteaga, Grace M.

    2015-01-01

    OBJECTIVES: With increasing complexity of critical care medicine comes an increasing need for multidisciplinary involvement in care. In many institutions, pharmacists are an integral part of this team, but long-term data on the interventions performed by pharmacists and their effects on patient care and outcomes are limited. We aimed to describe the role of pediatric clinical pharmacists in pediatric intensive care unit (PICU) practice. METHODS: We retrospectively reviewed the records of pharmacy interventions in the PICU at the Mayo Clinic in Rochester, Minnesota, from 2003-2013, with a distinct period of increased pharmacist presence in the PICU from 2008 onward. We compared demographic and outcome data on patients who did and who did not have pharmacy interventions during 2 periods (2003–2007 and 2008–2013). RESULTS: We identified 27,773 total interventions by pharmacists during the 11-year period, of which 79.8% were accepted by the clinical team. These interventions were made on 10,963 unique PICU admissions and prevented 5867 order entry errors. Pharmacists' interventions increased year over year, including a significant change in 2008. Patients who required pharmacy involvement were younger, sicker, and had longer intensive care unit, hospital, and ventilator duration. Average central line infections and central line entry rates decreased significantly over the study period. CONCLUSIONS: Increased pharmacist presence in the PICU is associated with increased interventions and prevention of adverse drug events. Pharmacist participation during rounds and order entry substantially improved the care of critically sick children and should be encouraged. PMID:26380569

  6. Fertility of testicular cancer patients after anticancer treatment--experience of 11 years.

    PubMed

    Molnár, Z; Berta, E; Benyó, M; Póka, R; Kassai, Z; Flaskó, T; Jakab, A; Bodor, M

    2014-06-01

    Testicular cancer affects men mostly in their reproductive age with a cure rate over 90%. Preserved fertility is one of the main concerns of the survivors. To further elucidate the question of fertility after anticancer treatment for testicular cancer, we performed a survey among patients who underwent sperm cryopreservation procedure in our department. A structured questionnaire was designed to collect data on demography, anticancer treatment, histological type of cancer, family planning intentions and fertility prior to and after treatment. During a period of 11 years 86 men underwent semen cryopreservation before starting chemo-or radiotherapy. Fifty-nine of them consented to participate in the study. The average length of follow up was 4.6 +/- 3.8 years. In case of 11.9% of the patients their banked sperm was used, which led to live birth in 57% of the couples. The partners of 6 patients became pregnant after in vitro fertilization (IVF) resulting in 4 live births and 2 miscarriages. The spontaneous pregnancy rate was 22%. Spontaneous pregnancy occurred in 13 partners resulting in 18 pregnancies followed by 12 live births, 2 artificial abortions and 4 miscarriages. We could not prove any association between preserved fertility and anticancer treatment or the histological type of the cancer. In conclusion, although spontaneous pregnancy rate is remarkably high after anticancer treatment for testicular cancer, the risk of infertility after receiving gonadotoxic treatment cannot be predicted. Cryopreservation is a safe and effective method to preserve fertility in these cases. As a result we strongly recommend discussing the advantages of semen cryopreservation with all patients awaiting treatment for testicular cancer.

  7. Regeneration of a Coastal Pine (Pinus thunbergii Parl.) Forest 11 Years after Thinning, Niigata, Japan

    PubMed Central

    Zhu, Jiaojun; Gonda, Yutaka; Yu, Lizhong; Li, Fengqin; Yan, Qiaoling; Sun, Yirong

    2012-01-01

    To examine the effects of thinning intensity on wind vulnerability and regeneration in a coastal pine (Pinus thunbergii) forest, thinning with intensities of 20%, 30% and 50% was conducted in December 1997; there was an unthinned treatment as the control (total 8 stands). We re-measured the permanent sites to assess the regeneration characteristics 11 years after thinning. In the 50% thinned stand, seedlings aged from 2 to 10 years exhibited the highest pine seedling density and growth. The age composition ranged from 1–3 years with densities of 9.9 and 5.1 seedlings m−2 in 30% and 20% thinned stands; only 1-year-old seedlings with a density of 6.1 seedlings m−2 in the unthinned stand. Similar trends were found for the regeneration of broadleaved species such as Robinia pseudoacacia and Prunus serrulata. We speculate that the canopy openness and moss coverage contributed to the regeneration success in the 50% thinned stand, while the higher litter depth and lack of soil moisture induced the regeneration failure in the unthinned stand. The stands thinned at 20% or 30% were less favourable for pine regeneration than the stands thinned at 50%. Therefore, thinning with less than 30% canopy openness (20% and 30% thinned stands) should be avoided, and thinning at higher than 30% canopy openness (50% thinned stand, approximately 1500 stems ha−1 at ages 40–50 years) is suggested for increasing regeneration in the coastal pine forest. The implications of thinning-based silviculture in the coastal pine forest management are also discussed. The ongoing development of the broadleaved seedlings calls for further observations. PMID:23091632

  8. Early puberty in 11-year-old girls: Millennium Cohort Study findings

    PubMed Central

    Zilanawala, Afshin; Sacker, Amanda; Hiatt, Robert; Viner, Russell

    2017-01-01

    Objective Early puberty in girls is linked to some adverse outcomes in adolescence and mid-life. We address two research questions: (1) Are socioeconomic circumstances and ethnicity associated with early onset puberty? (2) Are adiposity and/or psychosocial stress associated with observed associations? Design Longitudinal data on 5839 girls from the UK Millennium Cohort Study were used to estimate associations between ethnicity, family income, adiposity and psychosocial stress with a marker of puberty. Main outcome measure Reported menstruation at age 11 years. Results All quoted ORs are statistically significant. Girls in the poorest income quintile were twice as likely (OR=2.1), and the second poorest quintile nearly twice as likely (OR=1.9) to have begun menstruation compared with girls in the richest income quintile. Estimates were roughly halved on adjustment for Body Mass Index and markers of psychosocial stress (poorest, OR=1.5; second poorest, OR=1.5). Indian girls were over 3 times as likely compared with whites to have started menstruation (OR=3.5) and statistical adjustments did not attenuate estimates. The raised odds of menstruation for Pakistani (OR=1.9), Bangladeshi (OR=3.3) and black African (OR=3.0) girls were attenuated to varying extents, from about a third to a half, on adjustment for income and adiposity. Conclusions In contemporary UK, excess adiposity and psychosocial stress were associated with social inequalities in early puberty, while material disadvantage and adiposity were linked to ethnic inequalities in early puberty among girls. PMID:27672135

  9. Manipulative and antisocial behavior in an 11-year-old boy with epilepsy.

    PubMed

    Boes, Aaron D; Grafft, Amanda; Espe-Pfeifer, Patricia; Rowe, Jeffrey; Stein, Martin T

    2012-05-01

    Brian is an 11-year-old boy who presented to the emergency room with suicidal ideation and hearing voices. In the preceding weeks, he had escalating symptoms of oppositional defiant disorder, attention-deficit hyperactivity disorder (ADHD), and bipolar disorder. His medical history was notable for complex partial epilepsy with onset at age 4 that had been well controlled with divalproate. He had several mental health diagnoses by various practitioners including oppositional defiant disorder, ADHD, and bipolar disorder. Brian's family and social history was notable for the absence of identifiable risk factors for seizures or psychiatric problems. Over the course of a week-long psychiatric hospitalization, his complaints of depression and hearing voices seemed incongruent with his behavior. His parents endorsed a long history of Brian manipulating family and friends, such as conning his friends into stealing money and giving it to him. There was increasing suspicion that Brian was contriving his presenting symptoms for secondary gains. When his parents visited, he consistently bargained for prized items such as a long sought after cell phone and his own bedroom to improve his mood. His prior diagnoses (ADHD, a mood disorder, and oppositional defiant disorder) did not capture what seemed to be his core problem--an ability and willingness to manipulate others for his own self-serving purposes. Three months later, he was seen in the pediatric neurology clinic for increased seizure frequency. In the interim, he had several very serious altercations including setting fire to his family church, an attempted break-in-and-entry, assaulting his principal and resisting the arresting officer, and a malicious planned attack on his father where he struck him in the head with a crescent wrench "in cold blood, without any emotion."

  10. Somatotype in 6-11-year-old Italian and Estonian schoolchildren.

    PubMed

    Ventrella, A R; Semproli, S; Jürimäe, J; Toselli, S; Claessens, A L; Jürimäe, T; Brasili, P

    2008-01-01

    The study of somatotypes can contribute to the understanding of variability in human body build. The aim of this study was to compare the somatotypes of Italian and Estonian schoolchildren in order to evaluate factors that might lead to variability in somatotypes. The sample consisted of 762 Italian and 366 Estonian children aged 6-11 years. They were somatotyped by the Heath-Carter anthropometric method. Data on organised extra-curricular physical activity and hours of weekly training were also collected. One-way ANOVA was used to evaluate country-related variations of somatotype in each age/sex group, while factorial ANOVA was used to test the influence of country and organised physical activity on the variability of the anthropometric characteristics and somatotype components. There are significant differences in mean somatotypes between the Italian and Estonian children in many age classes and a different constitutional trend in children from the two different countries is observed. The Italian children are more endomorphic and less mesomorphic and ectomorphic than the Estonian children. On the other hand, it emerges from factorial ANOVA, that the somatotype components do not present significant variations related to organised physical activity and to the interaction between the country of origin and sport practice. Moreover, the results of the forward stepwise discriminant analyses show that mesomorphy is the best discriminator between the two countries, followed by ectomorphy. Our findings suggest that the observed differences between Italian and Estonian children could be related mainly to country rather than to the practice of organised physical activity in the two countries.

  11. Levels of selected urinary metabolites of volatile organic compounds among children aged 6-11 years.

    PubMed

    Jain, Ram B

    2015-10-01

    Data from National Health and Nutrition Examination Survey for the years 2011-2012 were used to evaluate variability in the observed levels of 20 urinary metabolites of volatile organic compounds (VOCs) by age, gender, and race/ethnicity among children aged 6-11 years. Exposure to environmental tobacco smoke was positively associated with the levels of selected metabolites of acrylonitrile, 1,3-butadiene, cyanide, and propylene oxide in a dose-response manner. Levels of the selected metabolites of acrolein, acrylonitrile, 1,3-butadiene, styrene, toluene, and xylene decreased with increase in age. Levels of 1-bromopropane decreased with number of rooms in the house but the reverse was true for 1,3-butadiene, carbon-disulfide, and N,N-dimethylformamide. Levels of most of the 20 metabolites did not vary with gender. Non-Hispanic white children had higher adjusted levels of N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine (AMCC), and phenylglyoxylic acid (PGA) than non-Hispanic black children. Non-Hispanic white children had statistically significantly higher adjusted levels of N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA), trans, trans-Muconic acid (MU), and N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine (AMCC) than non-Hispanic Asian children but statistically significantly lower levels of N-Acetyl-S-(n-propyl)-L-cysteine (BPMA) than non-Hispanic Asian children. Non-Hispanic Asian children had the lowest levels of 13 of the 20 metabolites among four major racial/ethnic groups but highest levels for three metabolites. For selected metabolites of acrolein, acrylamide, acrylonitrile-vinyl chloride-ethylene oxide, benzene, 1,3-butadien, crotonaldehyde, cyanide, ethylbenzene-styrene, and toluene, children had statistically significantly higher levels than nonsmoking adults. These results demonstrate how vulnerable children are to being exposed to harmful chemicals like VOCs in their own homes.

  12. Regeneration of a coastal pine (Pinus thunbergii Parl.) forest 11 years after thinning, Niigata, Japan.

    PubMed

    Zhu, Jiaojun; Gonda, Yutaka; Yu, Lizhong; Li, Fengqin; Yan, Qiaoling; Sun, Yirong

    2012-01-01

    To examine the effects of thinning intensity on wind vulnerability and regeneration in a coastal pine (Pinus thunbergii) forest, thinning with intensities of 20%, 30% and 50% was conducted in December 1997; there was an unthinned treatment as the control (total 8 stands). We re-measured the permanent sites to assess the regeneration characteristics 11 years after thinning. In the 50% thinned stand, seedlings aged from 2 to 10 years exhibited the highest pine seedling density and growth. The age composition ranged from 1-3 years with densities of 9.9 and 5.1 seedlings m(-2) in 30% and 20% thinned stands; only 1-year-old seedlings with a density of 6.1 seedlings m(-2) in the unthinned stand. Similar trends were found for the regeneration of broadleaved species such as Robinia pseudoacacia and Prunus serrulata. We speculate that the canopy openness and moss coverage contributed to the regeneration success in the 50% thinned stand, while the higher litter depth and lack of soil moisture induced the regeneration failure in the unthinned stand. The stands thinned at 20% or 30% were less favourable for pine regeneration than the stands thinned at 50%. Therefore, thinning with less than 30% canopy openness (20% and 30% thinned stands) should be avoided, and thinning at higher than 30% canopy openness (50% thinned stand, approximately 1500 stems ha(-1) at ages 40-50 years) is suggested for increasing regeneration in the coastal pine forest. The implications of thinning-based silviculture in the coastal pine forest management are also discussed. The ongoing development of the broadleaved seedlings calls for further observations.

  13. Training compliance control yields improved drawing in 5-11year old children with motor difficulties.

    PubMed

    Snapp-Childs, Winona; Shire, Katy; Hill, Liam; Mon-Williams, Mark; Bingham, Geoffrey P

    2016-08-01

    There are a large number of children with motor difficulties including those that have difficulty producing movements qualitatively well enough to improve in perceptuo-motor learning without intervention. We have developed a training method that supports active movement generation to allow improvement in a 3D tracing task requiring good compliance control. Previously, we tested a limited age range of children and found that training improved performance on the 3D tracing task and that the training transferred to a 2D drawing test. In the present study, school children (5-11years old) with motor difficulties were trained in the 3D tracing task and transfer to a 2D drawing task was tested. We used a cross-over design where half of the children received training on the 3D tracing task during the first training period and the other half of the children received training during the second training period. Given previous results, we predicted that younger children would initially show reduced performance relative to the older children, and that performance at all ages would improve with training. We also predicted that training would transfer to the 2D drawing task. However, the pre-training performance of both younger and older children was equally poor. Nevertheless, post-training performance on the 3D task was dramatically improved for both age groups and the training transferred to the 2D drawing task. Overall, this work contributes to a growing body of literature that demonstrates relatively preserved motor learning in children with motor difficulties and further demonstrates the importance of games in therapeutic interventions.

  14. Sunspot groups with high flare activity: Specific features of magnetic configuration, morphology, and dynamics

    NASA Astrophysics Data System (ADS)

    Fursyak, Yu. A.

    2016-12-01

    Specific features of the magnetic configuration, morphological structure, dynamics, and evolution of sunspot groups of the current (24th) cycle of solar activity with high flare activity are considered. The gradients of longitudinal magnetic fields at places of δ-configuration are calculated. The main finding is a time delay of 24-30 h between the time when the magnetic field gradient reaches a critical level of 0.1 G/km and the time when the first of powerful flares occurs in the active region. The study is based on data from the SDO and GOES-15 spacecrafts and ground-based solar telescopes (TST-2 at the Crimean Astrophysical Observatory of the Russian Academy of Sciences and the 150-foot telescope at the Mount Wilson Observatory).

  15. Analytical Model of an Asymmetric Sunspot with a Steady Plasma Flow in its Penumbra

    NASA Astrophysics Data System (ADS)

    Solov'ev, A. A.; Kirichek, E. A.

    2016-08-01

    A new exact analytical solution to the stationary problem of ideal magnetohydrodynamics is derived for an unipolar asymmetric sunspot immersed in a realistic solar atmosphere. The radial and vertical profiles of pressure, plasma density, and temperature in the visible layers of the sunspot are calculated. The reduction in plasma density in the magnetic funnel of the sunspot, corresponding to the Wilson depression, is also obtained. The magnetic structure of the sunspot is given analytically in a realistic way: a part of the magnetic flux of the sunspot approaches the surrounding photosphere at the outer edge of the penumbra. The magnetic field of the sunspot is not assumed to be axially symmetric. For the first time, the angular dependence of the physical variables in this model allows us to simulate not only a deviation from the circular shape of the sunspot, but also a fine filamentary structure of the sunspot penumbra. The Alfvén Mach number (the ratio of the plasma speed to the Alfvén speed) is zero at the center of the sunspot and rises slowly toward the periphery of the sunspot; this corresponds to the structure of the Evershed flow in the penumbra. The Evershed flow in our model is mainly concentrated in dark penumbral filaments, as is observed.

  16. Trends in cell phone use among children in the Danish national birth cohort at ages 7 and 11 years.

    PubMed

    Sudan, Madhuri; Olsen, Jørn; Sigsgaard, Torben; Kheifets, Leeka

    2016-11-01

    We prospectively examined trends in cell phone use among children in the Danish National Birth Cohort. Cell phone use was assessed at ages 7 and 11 years, and we examined use patterns by age, by year of birth, and in relation to specific individual characteristics. There was an increase in cell phone use from age 7 (37%) to 11 years (94%). There was a clear pattern of greater reported cell phone use among children at age 7 years with later birth year, but this trend disappeared at age 11. Girls and those who used phones at age 7 talked more often and for longer durations at age 11 years. Low socio-economic status and later year of birth were associated with voice calls at age 7 but not at age 11 years. At age 11 most used cell phones for texting and gaming more than for voice calls. Further, children who started using cell phones at age 7 years were more likely to be heavy cell phone voice users at age 11 years, making early use a marker for higher cumulative exposure regardless of year of birth. As cell phone technology continues to advance, new use patterns will continue to emerge, and exposure assessment research among children must reflect these trends.

  17. Stratospheric Temperature Trends in the 11 Years of AIRS Spectral Radiance Observations

    NASA Astrophysics Data System (ADS)

    Pan, F.; Huang, X.; Chen, X.; Guo, H.

    2014-12-01

    The AIRS (Atmospheric Infrared Sounder) level-1b radiances have been shown to be well calibrated (~0.3K or higher) and have little secular drift (~4mK/year) since its operation started in 2002. Given the rich information contained in the spectral radiances, such impressive instrument performances make AIRS radiances a valuable data set in the study of stratospheric climate. We compile 11 years (Sep 2002- Aug 2013) of AIRS radiances at channels in the CO2 v2 band with weighting functions peaked in the stratosphere. Using a state-of-the-art fast and accurate radiance simulator based on the PCRTM (Principle Component-based Radiative Transfer Model), we also simulate synthetic AIRS radiances at these channels based on two types of inputs: one is simulations by a free-running GFDL AM3 model and the other is ECMWF ERA-interim reanalysis. AIRS lower-stratospheric channels indicate a cooling trend of no more than 0.23 K/decade while its middle-stratospheric channels show a statistically significant cooling trend as large as 0.58 K/decade. Compared with AIRS observations, GFDL AM3 simulations underestimate the cooling trends in the middle-stratospheric channels while overestimate in the lower-stratospheric channels. Further simulations with separately varying CO2 and SST suggest that the change of CO2 alone is responsible for majority of the cooling trend in the middle-stratospheric channels, but the contributions of time-varying CO2 and SST are comparable in the lower-stratospheric channels. In contrast, the synthetic radiances based on ERA-interim reanalysis show statistically significant positive trends in virtually all stratospheric channels. We also compare the zonal-mean trends estimated from observed and synthetic AIRS spectral radiances and climate data records based on multi-decade SSU (Stratospheric Sounding Unit) measurements. Though discrepancies exist in terms of magnitude and seasonality of the cooling, they all show that most cooling occurs in the tropics

  18. FLUOR HANFORD (FH) MAKES CLEANUP A REALITY IN NEARLY 11 YEARS AT HANFORD

    SciTech Connect

    GERBER, M.S.

    2007-05-24

    For nearly 11 years, Fluor Hanford has been busy cleaning up the legacy of nuclear weapons production at one of the Department of Energy's (DOE'S) major sites in the United States. As prime nuclear waste cleanup contractor at the vast Hanford Site in southeastern Washington state, Fluor Hanford has changed the face of cleanup. Fluor beginning on October 1, 1996, Hanford Site cleanup was primarily a ''paper exercise.'' The Tri-Party Agreement, officially called the Hanford Federal Facility Agreement and Consent Order - the edict governing cleanup among the DOE, U.S. Environmental Protection Agency (EPA) and Washington state - was just seven years old. Milestones mandated in the agreement up until then had required mainly waste characterization, reporting, and planning, with actual waste remediation activities off in the future. Real work, accessing waste ''in the field'' - or more literally in huge underground tanks, decaying spent fuel POO{approx}{approx}S, groundwater, hundreds of contaminated facilities, solid waste burial grounds, and liquid waste disposal sites -began in earnest under Fluor Hanford. The fruits of labors initiated, completed and/or underway by Fluor Hanford can today be seen across the site. Spent nuclear fuel is buttoned up in secure, dry containers stored away from regional water resources, reactive plutonium scraps are packaged in approved containers, transuranic (TRU) solid waste is being retrieved from burial trenches and shipped offsite for permanent disposal, contaminated facilities are being demolished, contaminated groundwater is being pumped out of aquifers at record rates, and many other inventive solutions are being applied to Hanford's most intransigent nuclear wastes. (TRU) waste contains more than 100 nanocuries per gram, and contains isotopes higher than uranium on the Periodic Table of the Elements. (A nanocurie is one-billionth of a curie.) At the same time, Fluor Hanford has dramatically improved safety records, and cost

  19. Schoolyard physical activity of 6–11 year old children assessed by GPS and accelerometry

    PubMed Central

    2013-01-01

    Background Children’s current physical activity levels are disturbingly low when compared to recommended levels. This may be changed by intervening in the school environment. However, at present, it is unclear to what extent schoolyard physical activity contributes towards reaching the daily physical activity guideline. The aim of this study was to examine how long and at what intensity children are physically active at the schoolyard during different time segments of the day. Moreover, the contribution of schoolyard physical activity towards achieving the recommended guideline for daily physical activity was investigated. Methods Children (n=76) between the age of 6–11 years were recruited in six different schools in five cities (>70.000 residents) in the Netherlands. During the weekdays of a regular school week, childrens’ physical activity and location were measured with ActiGraph accelerometers and Travelrecorder GPS receivers. Data was collected from December 2008 to April 2009. From the data, the amount of moderate to vigorous physical activity (MVPA) on and outside the schoolyard was established. Moreover, the percentage of MVPA on the schoolyard was compared between the following segments of the day: pre-school, school, school recess, lunch break and post-school. Differences between boys and girls were compared using linear and logistic mixed-effects models. Results On average, children spent 40.1 minutes/day on the schoolyard. During this time, boys were more active on the schoolyard, with 27.3% of their time spent as MVPA compared to 16.7% among girls (OR=2.11 [95% CI 1.54 - 2.90]). The children were most active on the schoolyard during school recess, during which boys recorded 39.5% and girls recorded 23.4% of the time as MVPA (OR=2.55 [95% CI: 1.69 - 3.85]). Although children were only present at the schoolyard for 6.1% of the total reported time, this time contributed towards 17.5% and 16.8% of boys’ and girls’ minutes of MVPA. Conclusions On

  20. BLOOD PRESSURE, HEART RATE AND MELATONIN CYCLES SYNCHRONIZATION WITH THE SEASON, EARTH MAGNETISM AND SOLAR FLARES.

    PubMed

    Cornélissen, G; Halberg, F; Sothern, R B; Hillman, D C; Siegelová, J

    2010-01-01

    other aspect of RBS' physical environment, namely the seasons (at ~1.0 year), earth magnetism (at ~0.5 year) and/or solar flares (at ~0.42 year). Cosmic-biotic transfer of information, albeit hardly of energy (the biospheric amplitudes are very small) may be mediated in this set of frequency windows. As found earlier, RBS' circulation is also frequency-trapped environmentally in multidecadal windows, HR being locked into the transtridecadal Brückner, or rather Brückner-Egeson-Lockyer, BEL sunspot and terrestrial weather cycle, while his BP follows Hale's didecadal cycle in the changing polarity of sunspots.The ~0.41-year HR cycle may be associated with changes in solar flares, the cis-half-year amplitude of HR showing a cross-correlation coefficient of 0.79 with the total solar flare index (from both solar hemispheres) at a lag of ~3.2 years. The superposed time courses of these two variables indicate the presence of a shared Horrebow-Arago-Schwabe sunspot cycle of ~11 years, the cis-half-year in HR being more prominent after the total solar flare index reaches its ~11-year peak. Differences in the time-varying behavior of BP vs. HR are also described.

  1. Norms for the Wisconsin Card Sorting Test in 6- to 11-year-old children in Taiwan.

    PubMed

    Shu, B C; Tien, A Y; Lung, F W; Chang, Y Y

    2000-08-01

    The main aims of this study were to develop norms for the Wisconsin Card Sorting Test in 6- to 11-year-old children in Taiwan; to explore the effect of sex, age, birth order, number of siblings, and parental education on WCST performance in 6- to 11-year-old children; and to make a comparison of WCST performance between children in Taiwan and the USA. The results of this comparison of developmental norms of school children in Taiwan and the United States may facilitate the WCST as a clinical or research instrument in combination with other test procedures to assess aspects of cognitive and neuropsychological functioning of school children.

  2. Peculiarity of the Oscillation Stratification in Sunspot Penumbrae

    NASA Astrophysics Data System (ADS)

    Kolobov, D. Y.; Chelpanov, A. A.; Kobanov, N. I.

    2016-11-01

    Spatial distributions of the dominant oscillation frequency obtained for four sunspots show a feature shared by all the analysed levels of the solar atmosphere in these sunspots. This feature located in the inner penumbrae indicates that this region has favourable conditions for 2.5 - 4 mHz oscillation propagation. This agrees with the fact that the spectral composition of the oscillations at three atmospheric heights (Fe i 6173 Å, 1700 Å, and He ii 304 Å) in this region are similar. There has been previous evidence of particular similarities along the height of the photospheric magnetic field strength, line-of-sight velocity, and temperature profile in the inner penumbra, where the internal boundary of the Evershed flow is located. The finding of the same dominant oscillation frequency at a range of altitudes from the chromosphere up to the transition region extends the height range, suggesting similarities in physical conditions.

  3. ON THE SOURCE OF PROPAGATING SLOW MAGNETOACOUSTIC WAVES IN SUNSPOTS

    SciTech Connect

    Prasad, S. Krishna; Jess, D. B.; Khomenko, Elena

    2015-10-10

    Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether these oscillations are externally driven or generated in situ. We address this question by using observations of propagating slow magnetoacoustic waves along a coronal fan loop system. In addition to the generally observed decreases in oscillation amplitudes with distance, the observed wave amplitudes are also found to be modulated with time, with similar variations observed throughout the propagation path of the wave train. Employing multi-wavelength and multi-instrument data, we study the amplitude variations with time as the waves propagate through different layers of the solar atmosphere. By comparing the amplitude modulation period in different layers, we find that slow magnetoacoustic waves observed in sunspots are externally driven by photospheric p-modes, which propagate upward into the corona before becoming dissipated.

  4. Uncertainties in the Sunspot Numbers: Estimation and Implications

    NASA Astrophysics Data System (ADS)

    Dudok de Wit, Thierry; Lefèvre, Laure; Clette, Frédéric

    2016-11-01

    Sunspot number series are subject to various uncertainties that are still poorly known. The need to understand these better was recently highlighted by the major revision of the international Sunspot Number (Clette et al., in Space Sci. Rev. 186, 35, 2014). We present the first thorough estimation of these uncertainties, which behave as Poisson-like random variables with a multiplicative coefficient that is time- and observatory-dependent. We provide a simple expression for these uncertainties, and reveal how their evolution in time coincides with changes in the observations and processing of the data. Knowing their value is essential for properly building composites out of multiple observations, and for preserving the stability of the composites in time.

  5. Gauging the Nearness and Size of Cycle Minimum

    NASA Astrophysics Data System (ADS)

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

    1997-02-01

    By definition, the conventional onset for the start of a sunspot cycle is the time when smoothed sunspot number (i.e., the 12-month moving average) has decreased to its minimum value (called minimum amplitude) prior to the rise to its maximum value (called maximum amplitude) for the given sunspot cycle. On the basis (if the modern era sunspot cycles 10-22 and on the presumption that cycle 22 is a short-period cycle having a cycle length of 120 to 126 months (the observed range of short-period modern era cycles), conventional onset for cycle 23 should not occur until sometime between September 1996 and March 1997, certainly between June 1996 and June 1997, based on the 95-percent confidence level deduced from the mean and standard deviation of period for the sample of six short-pei-iod modern era cycles. Also, because the first occurrence of a new cycle, high-latitude (greater than or equal to 25 degrees) spot has always preceded conventional onset of the new cycle by at least 3 months (for the data-available interval of cycles 12-22), conventional onset for cycle 23 is not expected until about August 1996 or later, based on the first occurrence of a new cycle 23, high-latitude spot during the decline of old cycle 22 in May 1996. Although much excitement for an earlier-occurring minimum (about March 1996) for cycle 23 was voiced earlier this year, the present study shows that this exuberance is unfounded. The decline of cycle 22 continues to favor cycle 23 minimum sometime during the latter portion of 1996 to the early portion of 1997.

  6. Toward Waveform Heliotomography: Observing Interactions of Helioseismic Waves with a Sunspot

    NASA Astrophysics Data System (ADS)

    Zhao, Junwei; Kosovichev, Alexander G.; Ilonidis, Stathis

    2011-02-01

    We investigate how helioseismic waves that originate from effective point sources interact with a sunspot. These waves are reconstructed from observed stochastic wavefields on the Sun by cross-correlating photospheric Doppler-velocity signals. We select the wave sources at different locations relative to the sunspot, and investigate the p- and f-mode waves separately. The results reveal a complicated picture of waveform perturbations caused by the wave interaction with the sunspot. In particular, it is found that for waves originating from outside of the sunspot, p-mode waves travel across the sunspot with a small amplitude reduction and slightly higher speed, and wave amplitude and phase get mostly restored to the quiet-Sun values after passing the sunspot. The f-mode wave experiences some amplitude reduction passing through the sunspot, and the reduced amplitude is not recovered after that. The wave-propagation speed does not change before encountering the sunspot and inside the sunspot, but the wavefront becomes faster than the reference wave after passing through the sunspot. For waves originating from inside the sunspot umbra, both f- and p-mode waves show significant amplitude reductions and faster speed for all propagation paths. A comparison of positive and negative time lags of cross-correlation functions shows an apparent asymmetry in the waveform changes for both the f- and p-mode waves. We suggest that the waveform variations of the helioseismic waves interacting with a sunspot found in this article can be used for developing a method of waveform heliotomography, similar to the waveform tomography of the Earth.

  7. Determining sunspot positions in the classroom using the Carrington method

    NASA Astrophysics Data System (ADS)

    Galaviz, Pedro; Sánchez-Bajo, Florentino; Vaquero, José M.

    2016-07-01

    The method developed by Richard Carrington nearly 150 years ago is still very useful in order to determine the sunspot heliographic coordinates, owing to its simplicity and low cost equipment required. In this paper, we present a very detailed explanation of the procedure, along with an example of an application. With regard to this, the method can be employed successfully for educational purposes, due to the noticeable accuracy that it provides using a simple instrumental setup.

  8. Three-dimensional structure of a sunspot light bridge

    NASA Astrophysics Data System (ADS)

    Felipe, T.; Collados, M.; Khomenko, E.; Kuckein, C.; Asensio Ramos, A.; Balthasar, H.; Berkefeld, T.; Denker, C.; Feller, A.; Franz, M.; Hofmann, A.; Joshi, J.; Kiess, C.; Lagg, A.; Nicklas, H.; Orozco Suárez, D.; Pastor Yabar, A.; Rezaei, R.; Schlichenmaier, R.; Schmidt, D.; Schmidt, W.; Sigwarth, M.; Sobotka, M.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier, K. G.; Volkmer, R.; von der Lühe, O.; Waldmann, T.

    2016-11-01

    Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of the photospheric magnetic field is still lacking. Aims: We study the three-dimensional configuration of a sunspot, and in particular, its light bridge, during one of the last stages of its decay. Methods: We present the magnetic and thermodynamical stratification inferred from full Stokes inversions of the photospheric Si i 10 827 Å and Ca i 10 839 Å lines obtained with the GREGOR Infrared Spectrograph of the GREGOR telescope at the Observatorio del Teide, Tenerife, Spain. The analysis is complemented by a study of continuum images covering the disk passage of the active region, which are provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Results: The sunspot shows a light bridge with penumbral continuum intensity that separates the central umbra from a smaller umbra. We find that in this region the magnetic field lines form a canopy with lower magnetic field strength in the inner part. The photospheric light bridge is dominated by gas pressure (high-β), as opposed to the surrounding umbra, where the magnetic pressure is higher. A convective flow is observed in the light bridge. This flow is able to bend the magnetic field lines and to produce field reversals. The field lines merge above the light bridge and become as vertical and strong as in the surrounding umbra. We conclude that this occurs because two highly magnetized regions approach each other during the sunspot evolution. Movies associated to Figs. 2 and 13 are available at http://www.aanda.org

  9. 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.

  10. Significant statistically relationship between the great volcanic eruptions and the count of sunspots from 1610 to the present

    NASA Astrophysics Data System (ADS)

    Casati, Michele

    2014-05-01

    The assertion that solar activity may play a significant role in the trigger of large volcanic eruptions is, and has been discussed by many geophysicists. Numerous scientific papers have established a possible correlation between these events and the electromagnetic coupling between the Earth and the Sun, but none of them has been able to highlight a possible statistically significant relationship between large volcanic eruptions and any of the series, such as geomagnetic activity, solar wind, sunspots number. In our research, we compare the 148 volcanic eruptions with index VEI4, the major 37 historical volcanic eruptions equal to or greater than index VEI5, recorded from 1610 to 2012 , with its sunspots number. Staring, as the threshold value, a monthly sunspot number of 46 (recorded during the great eruption of Krakatoa VEI6 historical index, August 1883), we note some possible relationships and conduct a statistical test. • Of the historical 31 large volcanic eruptions with index VEI5+, recorded between 1610 and 1955, 29 of these were recorded when the SSN<46. The remaining 2 eruptions were not recorded when the SSN<46, but rather during solar maxima of the solar cycle of the year 1739 and in the solar cycle No. 14 (Shikotsu eruption of 1739 and Ksudach 1907). • Of the historical 8 large volcanic eruptions with index VEI6+, recorded from 1610 to the present, 7 of these were recorded with SSN<46 and more specifically, within the three large solar minima known : Maunder (1645-1710), Dalton (1790-1830) and during the solar minimums occurred between 1880 and 1920. As the only exception, we note the eruption of Pinatubo of June 1991, recorded in the solar maximum of cycle 22. • Of the historical 6 major volcanic eruptions with index VEI5+, recorded after 1955, 5 of these were not recorded during periods of low solar activity, but rather during solar maxima, of the cycles 19,21 and 22. The significant tests, conducted with the chi-square χ ² = 7,782, detect a

  11. Photospheric Origin of Three-minute Oscillations in a Sunspot

    NASA Astrophysics Data System (ADS)

    Chae, Jongchul; Lee, Jeongwoo; Cho, Kyuhyoun; Song, Donguk; Cho, Kyungsuk; Yurchyshyn, Vasyl

    2017-02-01

    The origin of the three-minute oscillations of intensity and velocity observed in the chromosphere of sunspot umbrae is still unclear. We investigated the spatio-spectral properties of the 3 minute oscillations of velocity in the photosphere of a sunspot umbra as well as those in the low chromosphere using the spectral data of the Ni i λ5436, Fe i λ5435, and Na i D2 λ5890 lines taken by the Fast Imaging Solar Spectrograph of the 1.6 m New Solar Telescope at the Big Bear Solar Observatory. As a result, we found a local enhancement of the 3 minute oscillation power in the vicinities of a light bridge (LB) and numerous umbral dots (UDs) in the photosphere. These 3 minute oscillations occurred independently of the 5 minute oscillations. Through wavelet analysis, we determined the amplitudes and phases of the 3 minute oscillations at the formation heights of the spectral lines, and they were found to be consistent with the upwardly propagating slow magnetoacoustic waves in the photosphere with energy flux large enough to explain the chromospheric oscillations. Our results suggest that the 3 minute chromospheric oscillations in this sunspot may have been generated by magnetoconvection occurring in the LB and UDs.

  12. 70 Years of Sunspot Observations at Kanzelhoehe Observatory

    NASA Astrophysics Data System (ADS)

    Pötzi, W.; Veronig, A.; Temmer, M.; Baumgartner, D. J.; Freislich, H.; Strutzmann, H.

    During World War II the German Airforce established a network of observatories, among them the Kanzelhöhe Observatory (KSO), which would provide information on solar activity in order to investigate the conditions of the Earth's ionosphere in terms of radio-wave propagation. Solar observations began already in 1943 with photographs of the photosphere and drawings of sunspots, plage regions and faculae, as well as patrol observations of the solar corona. Since 1944 relative sunspot numbers were derived, these relative numbers agree with the new International Sunspot Number tep[ISN,][]{SIDC,Clette2014} within ≈ 10%. However, revisiting the historical data, we also find periods with larger deviations. There were two main reasons for these deviations. On the one hand major instrumental changes took place and the instrument was relocated to another observation tower. On the other hand there were periods of frequent replacements of personnel. In the long term, the instrumental improvements led to better image quality, and a trend towards better seeing conditions since the year 2000 was found.

  13. MODELING THE CHROMOSPHERE OF A SUNSPOT AND THE QUIET SUN

    SciTech Connect

    Avrett, E.; Tian, H.; Landi, E.; Curdt, W.; Wülser, J.-P.

    2015-10-01

    Semiempirical atmospheric modeling attempts to match an observed spectrum by finding the temperature distribution and other physical parameters along the line of sight through the emitting region such that the calculated spectrum agrees with the observed one. In this paper we take the observed spectrum of a sunspot and the quiet Sun in the EUV wavelength range 668–1475 Å from the 2001 SUMER atlas of Curdt et al. to determine models of the two atmospheric regions, extending from the photosphere through the overlying chromosphere into the transition region. We solve the coupled statistical equilibrium and optically thick radiative transfer equations for a set of 32 atoms and ions. The atoms that are part of molecules are treated separately, and are excluded from the atomic abundances and atomic opacities. We compare the Mg ii k line profile observations from the Interface Region Imaging Spectrograph with the profiles calculated from the two models. The calculated profiles for the sunspot are substantially lower than the observed ones, based on the SUMER models. The only way we have found to raise the calculated Mg ii lines to agree with the observations is to introduce illumination of the sunspot from the surrounding active region.

  14. Weather variability, sunspots, and the blooms of cyanobacteria.

    PubMed

    Hu, Wenbiao; Connell, Des; Mengersen, Kerrie; Tong, Shilu

    2009-03-01

    The roles of weather variability and sunspots in the occurrence of cyanobacteria blooms, were investigated using cyanobacteria cell data collected from the Fred Haigh Dam, Queensland, Australia. Time series generalized linear model and classification and regression tree (CART) model were used in the analysis. Data on notified cell numbers of cyanobacteria and weather variables over the periods 2001 and 2005 were provided by the Australian Department of Natural Resources and Water, and Australian Bureau of Meteorology, respectively. The results indicate that monthly minimum temperature (relative risk [RR]: 1.13, 95% confidence interval [CI]: 1.02-1.25) and rainfall (RR: 1.11; 95% CI: 1.03-1.20) had a positive association, but relative humidity (RR: 0.94; 95% CI: 0.91-0.98) and wind speed (RR: 0.90; 95% CI: 0.82-0.98) were negatively associated with the cyanobacterial numbers, after adjustment for seasonality and auto-correlation. The CART model showed that the cyanobacteria numbers were best described by an interaction between minimum temperature, relative humidity, and sunspot numbers. When minimum temperature exceeded 18 degrees C and relative humidity was under 66%, the number of cyanobacterial cells rose by 2.15-fold. We conclude that weather variability and sunspot activity may affect cyanobacteria blooms in dams.

  15. Chromosphere above sunspots as seen at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Loukitcheva, Maria A.; Solanki, Sami K.; White, Stephen M.

    2011-08-01

    Millimeter emission is known to be a sensitive diagnostic of temperature and density in the solar chromosphere. In this work we use millimeter wave data to distinguish between various atmospheric models of sunspots, whose temperature structure in the upper photosphere and chromosphere has been the source of some controversy. From mm brightness simulations we expect a radio umbra to change its appearance from dark to bright (compared to the Quiet Sun) at a given wavelength in the millimeter spectrum (depending on the exact temperature in the model used). Thereby the millimeter brightness observed above an umbra at several wavelengths imposes strong constraints on temperature and density stratification of the sunspot atmosphere, in particular on the location and depth of the temperature minimum and the location of the transition region. Current mm/submm observational data suggest that brightness observed at short wavelengths is unexpectedly low compared to the most widely used sunspot models such as of Maltby et al. (1986). A successful model that is in agreement with millimeter umbral brightness should have an extended and deep temperature minimum (below 3000 K), such as in the models of Severino et al. (1994). However, we are not able to resolve the umbra cleanly with the presently available observations and better resolution as well as better wavelength coverage are needed for accurate diagnostics of umbral brightness at millimeter wavelengths. This adds one more scientific objective for the Atacama Large Millimeter/Submillimeter Array (ALMA).

  16. Sunspot Observations of Rudolf Wolf from 1849 - 1893

    NASA Astrophysics Data System (ADS)

    Friedli, Thomas K.

    2016-11-01

    The sunspot observations of Rudolf Wolf form the core of the Wolf series of sunspot relative numbers, or Wolf numbers, since his observations define the original scale of the series and also the main course of solar activity from 1849 to 1893. Unfortunately, the raw data for the years 1856 to 1869 were never published in full detail. The heritage group of the Rudolf Wolf Society in Switzerland digitized parts of the hitherto unpublished original source book of the Wolf series and put it on its website www.wolfinstitute.ch . Now, the Wolf numbers from 1849 to 1876, as provided by the World Data Center for Solar Index and Long-term Solar Observations (WDC-SILSO), can be reconstructed in every detail, since the source book contains all the raw sunspot group and individual spot numbers as well as the implemented calibration and interpolation methods. Thus, the observations made by Rudolf Wolf with the 83/1320 mm Fraunhofer refractor and with the 40/700 mm Parisian refractor as well as those made by Heinrich Schwabe can be identified and separated now. In this article, we describe Wolf's instruments and methods of observation. An inspection of the source book and other published sources reveals that the calibration factor of the 40/700 mm Parisian refractor should probably be lowered. Since no appropriate comparison observations are available, the scale transfer from Heinrich Schwabe to Rudolf Wolf has to be analyzed further.

  17. Magnetic field variations in the umbra of single sunspots during their passage across the solar disk

    NASA Astrophysics Data System (ADS)

    Zagainova, Iu. S.; Fainshtein, V. G.; Obridko, V. N.; Rudenko, G. V.

    2016-12-01

    Temporal variations of the maximum ( B max) and average (< B>) magnetic inductions, minimum ( α min) and average (< α>) inclination angles of the field lines to the radial direction from the center of the Sun, and areas of the sunspot umbra S in the umbra of single sunspots during their passage across the solar disk are investigated. The variation of the properties of single sunspots has been considered at different stages of their existence, i.e., during formation, the "quiet" period, and the disappearance stage. It has been found that, for the majority of the selected single sunspots, there is a positive correlation between B max and S and between and S defined at different times during the passage of sunspots across the solar disk. It is shown in this case that the nature of the dependence between the parameters α min and B max, α min and S, as well as between < α> and < B>, < α> and S, can vary from sunspot to sunspot, but for many sunspots the inclination angle of the field lines decreases on average with the growth of the sunspot umbra area and the field strength.

  18. Dependence of sunspot photospheric waves on the depth of the source of solar p-modes

    NASA Astrophysics Data System (ADS)

    Felipe, T.; Khomenko, E.

    2017-02-01

    Photospheric waves in sunspots moving radially outward at speeds faster than the characteristic wave velocities have been recently detected. It has been suggested that they are the visual pattern of p-modes excited around 5 Mm beneath the sunspot's surface. Using numerical simulations, we performed a parametric study of the waves observed at the photosphere and higher layers that were produced by sources located at different depths beneath the sunspot's surface. The observational measurements are consistent with waves driven between approximately 1 Mm and 5 Mm below the sunspot's surface.

  19. The Development of Rhythm at the Age of 6-11 Years: Non-Pitch Rhythmic Improvisation

    ERIC Educational Resources Information Center

    Paananen, Pirkko

    2006-01-01

    In the statistical and transcriptional analyses reported in this exploratory study, original rhythms of 6-11-year-old children (N=36) were examined. The hypotheses were based on a new model of musical development, and tested empirically using non-pitch rhythmic improvisation in a MIDI-environment. Several representational types were found in…

  20. Teachers' and Pupils' Behavior in Large and Small Classes: A Systematic Observation Study of Pupils Aged 10 and 11 Years

    ERIC Educational Resources Information Center

    Blatchford, Peter; Bassett, Paul; Brown, Penelope

    2005-01-01

    The authors examined class size effects on teacher-pupil interactions, pupil engagement, and pupil-pupil interaction. They extended previous research by recognizing the hierarchical nature of observation data and the possible influence of other variables. The study used a time sampling method involving 257 children (aged 10-11 years) in 16 small…

  1. Expectations and Levels of Understanding When Using Mobile Phones among 9-11-Year Olds in Wales, UK

    ERIC Educational Resources Information Center

    Turley, Joanne; Baker, Sally-Ann; Lewis, Christopher Alan

    2014-01-01

    There is growing interest in examining the use of mobile technology among children. The present study extended this literature among a sample of 9-11-year olds in Wales, UK in three ways. First, to examine the level of mobile phone ownership; second, to consider how mobile phones are used, investigate timescales and expectations when communicating…

  2. Upper School Maths: Lesson Plans and Activities for Ages 9-11 Years. Series of Caribbean Volunteer Publications, No. 9.

    ERIC Educational Resources Information Center

    Voluntary Services Overseas, Castries (St. Lucia).

    This collection of lesson plans and activities for students aged 9-11 years is based on a science curriculum developed by a group of Caribbean nations. The activities pertain to topics such as place value, prime and composite numbers, the sieve of Eratosthenes, square numbers, factors and multiples, sequences, averages, geometry, symmetry,…

  3. An Evaluation of Computerised Essay Marking for National Curriculum Assessment in the UK for 11-Year-Olds

    ERIC Educational Resources Information Center

    Hutchison, Dougal

    2007-01-01

    This paper reports a comparison of human and computer marking of approximately 600 essays produced by 11-year-olds in the UK. Each essay script was scored by three human markers. Scripts were also scored by the "e-rater" program. There was a good agreement between human and machine marking. Scripts with highly discrepant scores were…

  4. Predictors of Meeting Physical Activity and Fruit and Vegetable Recommendations in 9-11-Year-Old Children

    ERIC Educational Resources Information Center

    Beck, Jimikaye; De Witt, Peter; McNally, Janise; Siegfried, Scott; Hill, James O; Stroebele-Benschop, Nanette

    2015-01-01

    Objective: Childhood obesity represents a significant public health problem. This study examined physical activity and nutrition behaviours and attitudes of 9-11-year-olds, and factors influencing these behaviours. Design: Study participants recorded pedometer steps for 7 days and completed physical activity enjoyment, food attitudes and food…

  5. Comparative Analysis of Musical Abilities of 11-Year-Olds from Slovenia and the Island of Martinique

    ERIC Educational Resources Information Center

    Jerman, Janez; Pretnar, Tatjana

    2006-01-01

    The focus of the study is the comparison between the musical abilities of 11-year-old children on the island of Martinique and in Slovenia, and finding out to what extent their development of musical abilities is influenced by musical and cultural family background, music school attendance, choral singing and playing orchestral instruments. Our…

  6. Internet Use and Psychological Well-Being among 10-Year-Old and 11-Year-Old Children

    ERIC Educational Resources Information Center

    Devine, Paula; Lloyd, Katrina

    2012-01-01

    This paper uses data from the 2009 Kids' Life and Times Survey, involving 3657 children aged 10 or 11 years old in Northern Ireland. The survey indicated high levels of use of Internet applications, including social-networking sites and online games. Using the KIDSCREEN-27 instrument, the data indicate that the use of social-networking sites and…

  7. Effect of Ball Mass on Dribble, Pass, and Pass Reception in 9-11-Year-Old Boys' Basketball

    ERIC Educational Resources Information Center

    Arias, Jose L.; Argudo, Francisco M.; Alonso, Jose I.

    2012-01-01

    The objective of the study was to analyze the effect of ball mass on dribble, pass, and pass reception in real game situations in 9-11-year-old boys' basketball. Participants were 54 boys identified from six federated teams. The independent variable was ball mass, and dependent variables were number of dribbles, passes, and pass receptions. Three…

  8. Element pool changes within a scrub-oak ecosystem after 11 years of elevated CO2 exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elevated CO2 effects on soil element pool size and fluxes are equivocal. We measured above and belowground pools of non-nitrogen macro and micronutrients in a Florida scrub-oak ecosystem exposed to twice-ambient CO2 concentrations for 11 years. We quantified element pools in above ground biomass of ...

  9. Evaluation of Low-Cost, Objective Instruments for Assessing Physical Activity in 10-11-Year-Old Children

    ERIC Educational Resources Information Center

    Hart, Teresa L.; Brusseau, Timothy; Kulinna, Pamela Hodges; McClain, James J.; Tudor-Locke, Catrine

    2011-01-01

    This study compared step counts detected by four, low-cost, objective, physical-activity-assessment instruments and evaluated their ability to detect moderate-to-vigorous physical activity (MVPA) compared to the ActiGraph accelerometer (AG). Thirty-six 10-11-year-old children wore the NL-1000, Yamax Digiwalker SW 200, Omron HJ-151, and Walk4Life…

  10. Using Authentic Picture Books and Illustrated Books to Improve L2 Writing among 11-Year-Olds

    ERIC Educational Resources Information Center

    Birketveit, Anna; Rimmereide, Hege Emma

    2017-01-01

    The case study investigates what impact extensive reading of authentic picture books/illustrated books had on the learners' writing skills in a Norwegian EFL (English as a foreign language) classroom of 11-year-olds. Furthermore, the study also looks into the importance the pictures/illustrations had for the learners and what type of picture-text…

  11. Maximal Voluntary Static Force Production Characteristics of Skeletal Muscle in Children 8-11 Years of Age.

    ERIC Educational Resources Information Center

    Going, Scott B.; And Others

    1987-01-01

    A study of maximal voluntary isometric muscle contraction force-time curves among 32 normal, healthy 8- to 11-year-olds performing tasks involving separate muscle groups found that force and maximal rate of force increase were quite reproducible, but time to selected force levels reflected considerable variations. (Author/CB)

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Anticipating Cycle 24 Minimum and its Consequences: An Update

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    This Technical Publication updates estimates for cycle 24 minimum and discusses consequences associated with cycle 23 being a longer than average period cycle and cycle 24 having parametric minimum values smaller (or larger for the case of spotless days) than long term medians. Through December 2007, cycle 23 has persisted 140 mo from its 12-mo moving average (12-mma) minimum monthly mean sunspot number occurrence date (May 1996). Longer than average period cycles of the modern era (since cycle 12) have minimum-to-minimum periods of about 139.0+/-6.3 mo (the 90-percent prediction interval), inferring that cycle 24 s minimum monthly mean sunspot number should be expected before July 2008. The major consequence of this is that, unless cycle 24 is a statistical outlier (like cycle 21), its maximum amplitude (RM) likely will be smaller than previously forecast. If, however, in the course of its rise cycle 24 s 12-mma of the weighted mean latitude (L) of spot groups exceeds 24 deg, then one expects RM >131, and if its 12-mma of highest latitude (H) spot groups exceeds 38 deg, then one expects RM >127. High-latitude new cycle spot groups, while first reported in January 2008, have not, as yet, become the dominant form of spot groups. Minimum values in L and H were observed in mid 2007 and values are now slowly increasing, a precondition for the imminent onset of the new sunspot cycle.

  17. Trichotillomania: Bizzare Patern of Hair Loss at 11-Year-old Girl.

    PubMed

    Zímová, Jana; Zímová, Pavlína

    2016-06-01

    Trichotillomania (TTM) is defined by the Diagnostics and Statistic Manual of Mental Disorders, 4th edition (DMS-IV) as hair loss from a patient`s repetitive self-pulling of hair. The disorder is included under anxiety disorders because it shares some obsessive-compulsive features. Patients have the tendency towards feelings of unattractiveness, body dissatisfaction, and low self-esteem (1,2). It is a major psychiatric problem, but many patients with this disorder first present to a dermatologist. An 11-year-old girl came to our department with a 2-month history of diffuse hair loss on the frontoparietal and parietotemporal area (Figure 1). She had originally been examined by a pediatrician with the diagnosis of alopecia areata. The patient`s personal history included hay fever and shortsightedness, and she suffered from varicella and mononucleosis. Nobody in the family history suffered from alopecia areata, but her father has male androgenetic alopecia (Norwood/Hamilton MAGA C3F3). The mother noticed that the child had had changeable mood for about 2 months and did not want to communicate with other persons in the family. The family did not have any pet at home. At school, her favorite subjects were Math and Computer Studies. She did not like Physical Education and did not participate in any sport activities during her free time. This was very strange because she was obese (body-mass index (BMI) 24.69). She was sometimes angry with her 13-year-old sister who had better results at school. The girl had suddenly started to wear a blue scarf. The parents did not notice that she pulled out her hair at home. Dermatological examination of the capillitium found a zone of incomplete alopecia in the frontoparietal and parietotemporal area, without inflammation, desquamation, and scaring. Hairs were of variable length (Figure 1). There was a patch of incomplete alopecia above the forehead between two stripes of hair of variable length (Figure 2). The hair pull test was

  18. Numerical Simulation of Propagation and Transformation of the MHD Waves in Sunspots

    NASA Astrophysics Data System (ADS)

    Parchevsky, Konstantin; Zhao, J.; Kosovichev, A.

    2010-05-01

    Direct numerical simulation of propagation of MHD waves in stratified medium in regions with non-uniform magnetic field is very important for understanding of scattering and transformation of waves by sunspots. We present numerical simulations of wave propagation through the sunspot in 3D. We compare results propagation in two different magnitostatic models of sunspots refferred to as "deep" and "shallow" models. The "deep" model has convex shape of magnetic field lines near the photosphere and non-zero horizorntal perturbations of the sound speed up to the bottom of the model. The "shallow" model has concave shape of the magnetic field lines near the photosphere and horizontally uniform sound speed below 2 Mm. Waves reduce their amplitude when they reach the center of the sunspot and estore the amplitude when pass the center. For the "deep" model this effect is bigger than for the "shallow" model. The wave amplitude depends on the distance of the source from the sunspot center. For the "shallow" model and source distance of 9 Mm from the sunspot center the wave amplitude at some moment (when the wavefront passes the sunspot center) becomes bigger inside the sunspot than outside. For the source distance of 12 Mm the wave amplitude remains smaller inside the sunspot than outside for all moments of time. Using filtering technique we separated magnetoacoustic and magnetogravity waves. Simulations show that the sunspot changes the shape of the wave front and amplitude of the f-modes significantly stronger than the p-modes. It is shown, that inside the sunspot magnetoacoustic and magnetogravity waves are not spatially separated unlike the case of the horizontally uniform background model. We compared simulation results with the wave signals (Green's functions) extracted from the SOHO/MDI data for AR9787.

  19. 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.

  20. 22 year cycle in the imbalance of the photospheric magnetic fluxes

    NASA Astrophysics Data System (ADS)

    Vernova, Elena; Baranov, Dmitrii; Tyasto, Marta

    The manifestation of the 22 year solar magnetic cycle in the imbalance of positive and negative photospheric magnetic fluxes is studied. For the analysis we use synoptic maps of the photospheric magnetic field of Kitt Peak Observatory (1976 - 2003) and John Wilcox Observatory in Stanford (1976 - 2012). We consider strong magnetic fields for the heliolatitudes in the interval from +40° to -40°. It is shown that the sign of the imbalance between positive and negative fluxes remains constant during 11 years from one inversion of the Sun’s global magnetic field to the next one and always coincides with the sign of the polar field in the Northern hemisphere. Thus, the imbalance between the magnetic fluxes of different polarities changes according to the 22 year cycle. The sign of the imbalance is determined both by the phase of the solar cycle (before or after the inversion) and by the parity of the solar cycle. The imbalance of positive and negative magnetic fluxes can be observed not only for the strong fields in the sunspot zone. The mean magnetic field of the Sun (Sun as a star), which is determined by the net flux of the background fields, changes according to the same pattern as the imbalance of the strong fields. The regular changes of the imbalance of the photospheric magnetic fields are reflected also in the parameters of heliosphere. We show the connection of the imbalance with the quadrupole component of the photospheric magnetic field and with the imbalance of the interplanetary magnetic field (the difference between the numbers of the days with positive and negative polarities of the interplanetary magnetic field near Earth).

  1. Signature of high-order azimuthal MHD body modes in sunspot's low atmosphere

    NASA Astrophysics Data System (ADS)

    Yuan, Ding

    2015-09-01

    The five-minute oscillations inside sunspots appear to be the absorption of the solar p-mode. It is a potential tool to probe a sunspot's sub-structure. We studied the collective properties of five-minute oscillations in the power and phase distribution at the sunspot's umbra-penumbra boundary. The azimuthal distributions of the power and phase of five-minute oscillations enclosing a sunspot's umbra were obtained with images taken with the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA). The azimuthal modes were quantified with periodogram analysis and justified with significance tests. The azimuthal nodal structures in an approximately axially symmetric sunspot AR 11131 (2010 Dec 08) were investigated. Mode numbers m = 2,3,4,7,10 were obtained in both 1700 Å and 1600 Å bandpasses. The 1600 Å channel also revealed an extra mode at m = 9. In the upper atmosphere (304 Å), fewer modes were detected at m = 3, 4, 7. The azimuthal modes in the sunspot's low atmosphere could be interpreted as high-order azimuthal MHD body modes. They were detected in the power and phase of the five-minute oscillations in sunspot AR 11131 with SDO/AIA data. Fewer modes were detected in the sunspot's upper atmosphere.

  2. Cross Recurrence Plots Analysis of the North-South Sunspot Activities

    NASA Astrophysics Data System (ADS)

    Ponyavin, Dmitri I.; Zolotova, Nadejda V.

    A new technique of nonlinear interrelations between time series developed by Marwan & Kurths, (2002) has been applied to the sunspot data. By using this tools we have investigated synchronization and phase difference in annual sunspot areas -- time series available for Northern and Southern Hemispheres of the Sun.

  3. Magnetic and Thermal Contributions to Helioseismic Travel times in Simulated Sunspots

    NASA Astrophysics Data System (ADS)

    Braun, Douglas; Felipe, Tobias; Birch, Aaron; Crouch, Ashley D.

    2016-05-01

    The interpretation of local helioseismic measurements of sunspots has long been a challenge, since waves propagating through sunspots are potentially affected by both mode conversion and changes in the thermal structure of the spots. We carry out numerical simulations of wave propagation through a variety of models which alternately isolate either the thermal or magnetic structure of the sunspot or include both of these. We find that helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. Using insight from ray theory, we find that travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level of the measurements) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it suggests a path towards inversions for sunspot structure. This research has been funded by the Spanish MINECO through grant AYA2014-55078-P, by the NASA Heliophysics Division through NNX14AD42G and NNH12CF23C, and the NSF Solar Terrestrial program through AGS-1127327.

  4. Weight status associations with physical activity intensity and physical self-perceptions in 10- to 11-year-old children.

    PubMed

    Fairclough, Stuart J; Boddy, Lynne M; Ridgers, Nicola D; Stratton, Gareth

    2012-02-01

    The study examined associations between children's weight status, physical activity intensity, and physical self-perceptions. Data were obtained from 409 children (224 girls) aged 10-11 years categorized as normal-weight or overweight/obese. Physical activity was assessed using accelerometry, and children completed the Physical Self-Perception Profile. After controlling for the effects of age, maturation, and socioeconomic status vigorous physical activity was significantly associated with normal-weight status among boys (OR = 1.13, p = .01) and girls (OR = 1.13, p = .03). Normal-weight status was significantly associated with perceived Physical Condition (Boys: OR = 5.05, p = .008; Girls: OR = 2.50, p = .08), and Body Attractiveness (Boys: OR = 4.44, p = .007; Girls: OR = 2.56, p = .02). Weight status of 10-11 year old children was significantly associated with time spent in vigorous physical activity and self-perceptions of Body Attractiveness and Physical Condition.

  5. An 11-year follow-up study of neonatal-onset, bath-induced alternating hemiplegia of childhood in twins.

    PubMed

    Incorpora, Gemma; Pavone, Piero; Polizzi, Agata; Cocuzza, Mariadonatella; Privitera, Michael; Pavone, Lorenzo; Ruggieri, Martino

    2012-05-01

    The authors previously reported on the initial manifestations in a set of female twins, who presented soon after birth with bath-induced paroxysmal events each time they were immersed in a warm water bath. These episodes progressively ceased by the age of 36 months, replaced by paroxysmal episodes of alternating hemiplegia unrelated to water immersion. By age 4 years, the twins developed the classic features of alternating hemiplegia of childhood. Clinical outcomes at the age of 11 years are now reported. Standard and video-electroencephalograms showed a large, slow background activity followed by lower amplitude waves without focal abnormalities or other abnormal findings. This represents the first report on (a) alternating hemiplegia of childhood started with bath-induced paroxysmal episodes; (b) this condition in monozygotic twins; and (c) an 11-year follow-up study in which the twins continue to experience episodes of alternating hemiplegia in the setting of baseline cognitive impairment without epileptic episodes.

  6. Changes in element contents of four lichens over 11 years in the Boundary Waters Canoe Area Wilderness, northern Minnesota

    USGS Publications Warehouse

    Bennett, J.P.; Wetmore, C.M.

    1999-01-01

    Four species of lichen (Cladina rangiferina, Evernia mesomorpha, Hypogymnia physodes, and Parmelia sulcata) were sampled at six locations in the Boundary Waters Canoe Area Wilderness three times over a span of 11 years and analyzed for concentrations of 16 chemical elements to test the hypotheses that corticolous species would accumulate higher amounts of chemical elements than terricolous species, and that 11 years were sufficient to detect spatial patterns and temporal trends in element contents. Multivariate analyses of over 2770 data points revealed two principal components that accounted for 68% of the total variance in the data. These two components, the first highly loaded with Al, B, Cr, Fe, Ni and S, and the second loaded with Ca, Cd, Mg and Mn, were inversely related to each other over time and space. The first component was interpreted as consisting of an anthropogenic and a dust component, while the second, primarily a nutritional component. Cu, K, Na, P, Pb and Zn were not highly loaded on either component. Component 1 decreased significantly over the 11 years and from west to east, while component 2 increased. The corticolous species were more enriched in heavy metals than the terricolous species. All four elements in component 2 in H. physodes were above enrichment thresholds for this species. Species differences on the two components were greater than the effects of time and space, suggesting that biomonitoring with lichens is strongly species dependent. Some localities in the Boundary Waters Canoe Area Wilderness appear enriched in some anthropogenic elements for no obvious reasons.

  7. Automatic Detection of Magnetic δ in Sunspot Groups

    NASA Astrophysics Data System (ADS)

    Padinhatteeri, Sreejith; Higgins, Paul A.; Bloomfield, D. Shaun; Gallagher, Peter T.

    2016-01-01

    Large and magnetically complex sunspot groups are known to be associated with flares. To date, the Mount Wilson scheme has been used to classify sunspot groups based on their morphological and magnetic properties. The most flare-prolific class, the δ sunspot group, is characterised by opposite-polarity umbrae within a common penumbra, separated by less than 2∘. In this article, we present a new system, called the Solar Monitor Active Region Tracker-Delta Finder (SMART-DF), which can be used to automatically detect and classify magnetic δs in near-realtime. Using continuum images and magnetograms from the Helioseismic and Magnetic Imager (HMI) onboard NASA's Solar Dynamics Observatory (SDO), we first estimate distances between opposite-polarity umbrae. Opposite-polarity pairs with distances of less that 2∘ are then identified, and if these pairs are found to share a common penumbra, they are identified as a magnetic δ configuration. The algorithm was compared to manual δ detections reported by the Space Weather Prediction Center (SWPC), operated by the National Oceanic and Atmospheric Administration (NOAA). SMART-DF detected 21 out of 23 active regions (ARs) that were marked as δ spots by NOAA during 2011 - 2012 (within {±} 60° longitude). SMART-DF in addition detected five ARs that were not announced as δ spots by NOAA. The near-realtime operation of SMART-DF resulted in many δs being identified in advance of NOAA's daily notification. SMART-DF will be integrated into SolarMonitor (www.solarmonitor.org) and the near-realtime information will be available to the public.

  8. Flocculent Flows in the Chromospheric Canopy of a Sunspot

    NASA Astrophysics Data System (ADS)

    Vissers, Gregal; Rouppe van der Voort, Luc

    2012-05-01

    High-quality imaging spectroscopy in the Hα line, obtained with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m solar Telescope (SST) at La Palma and covering a small sunspot and its surroundings, is studied. They exhibit ubiquitous flows both along fibrils making up the chromospheric canopy away from the spot and in the superpenumbra. We term these flows "flocculent" to describe their intermittent character, that is, morphologically reminiscent of coronal rain. The flocculent flows are investigated further in order to determine their dynamic and morphological properties. For the measurement of their characteristic velocities, accelerations, and sizes, we employ a new versatile analysis tool, the CRisp SPectral EXplorer (CRISPEX), which we describe in detail. Absolute velocities on the order of 7.2-82.4 km s-1 are found, with an average value of 36.5 ± 5.9 km s-1 and slightly higher typical velocities for features moving toward the sunspot than away. These velocities are much higher than those determined from the shift of the line core, which shows patches around the sunspot with velocity enhancements of up to 10-15 km s-1 (both red- and blueshifted). Accelerations are determined for a subsample of features that show clear accelerating or decelerating behavior, yielding an average of 270 ± 63 m s-2 and 149 ± 63 m s-2 for the accelerating and decelerating features, respectively. Typical flocculent features measure 627 ± 44 km in length and 304 ± 30 km in width. On average, 68 features are detected per minute, with an average lifetime of 67.7 ± 8.8 s. The dynamics and phenomenology of the flocculent flows suggest they may be driven by a siphon flow, where the flocculence could arise from a density perturbation close to one of the footpoints or along the loop structure.

  9. Signatures of running penumbral waves in sunspot photospheres

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, J.; Bello González, N.

    2015-08-01

    Context. The highly dynamic atmosphere above sunspots exhibits a wealth of magnetohydrodynamic waves. Recent studies suggest a coupled nature of the most prominent phenomena: umbral flashes and running penumbral waves (RPWs). Aims: From an observational point of view, we perform a height-dependent study of RPWs, compare their wave characteristics, and aim to track down these so far only chromospherically observed phenomena to photospheric layers to prove the upward propagating field-guided nature of RPWs. Methods: We analyze a time series (58 min) of multiwavelength observations of an isolated circular sunspot (NOAA11823) taken at high spatial and temporal resolution in spectroscopic mode with the Interferometric BIdimensional Spectro-polarimeter (IBIS/DST). By means of a multilayer intensity sampling, velocity comparisons, wavelet power analysis, and sectorial studies of time slices, we retrieve the power distribution, characteristic periodicities, and propagation characteristics of sunspot waves at photospheric and chromospheric levels. Results: Signatures of RPWs are found at photospheric layers. Those continuous oscillations occur preferably at periods between 4-6 min starting at the inner penumbral boundary. The photospheric oscillations all have a slightly delayed, more defined chromospheric counterpart with larger relative velocities, which are linked to preceding umbral flash events. In all of the layers, the power of RPWs follows a filamentary fine-structure and shows a typical ring-shaped power distribution increasing in radius for larger wave periods. The analysis of time slices reveals apparent horizontal velocities for RPWs at photospheric layers of ≈51 km s-1, which decrease to ≈37 km s-1 at chromospheric heights. Conclusions: The observations strongly support the scenario of RPWs being upward propagating slow-mode waves guided by the magnetic field lines. Clear evidence for RPWs at photospheric layers is given. The inverse proportionality of the

  10. FLOCCULENT FLOWS IN THE CHROMOSPHERIC CANOPY OF A SUNSPOT

    SciTech Connect

    Vissers, Gregal; Rouppe van der Voort, Luc

    2012-05-01

    High-quality imaging spectroscopy in the H{alpha} line, obtained with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m solar Telescope (SST) at La Palma and covering a small sunspot and its surroundings, is studied. They exhibit ubiquitous flows both along fibrils making up the chromospheric canopy away from the spot and in the superpenumbra. We term these flows 'flocculent' to describe their intermittent character, that is, morphologically reminiscent of coronal rain. The flocculent flows are investigated further in order to determine their dynamic and morphological properties. For the measurement of their characteristic velocities, accelerations, and sizes, we employ a new versatile analysis tool, the CRisp SPectral EXplorer (CRISPEX), which we describe in detail. Absolute velocities on the order of 7.2-82.4 km s{sup -1} are found, with an average value of 36.5 {+-} 5.9 km s{sup -1} and slightly higher typical velocities for features moving toward the sunspot than away. These velocities are much higher than those determined from the shift of the line core, which shows patches around the sunspot with velocity enhancements of up to 10-15 km s{sup -1} (both red- and blueshifted). Accelerations are determined for a subsample of features that show clear accelerating or decelerating behavior, yielding an average of 270 {+-} 63 m s{sup -2} and 149 {+-} 63 m s{sup -2} for the accelerating and decelerating features, respectively. Typical flocculent features measure 627 {+-} 44 km in length and 304 {+-} 30 km in width. On average, 68 features are detected per minute, with an average lifetime of 67.7 {+-} 8.8 s. The dynamics and phenomenology of the flocculent flows suggest they may be driven by a siphon flow, where the flocculence could arise from a density perturbation close to one of the footpoints or along the loop structure.

  11. Distribution of electric currents in sunspots from photosphere to corona

    SciTech Connect

    Gosain, Sanjay; Démoulin, Pascal; López Fuentes, Marcelo

    2014-09-20

    We present a study of two regular sunspots that exhibit nearly uniform twist from the photosphere to the corona. We derive the twist parameter in the corona and in the chromosphere by minimizing the difference between the extrapolated linear force-free field model field lines and the observed intensity structures in the extreme-ultraviolet images of the Sun. The chromospheric structures appear more twisted than the coronal structures by a factor of two. Further, we derive the vertical component of electric current density, j{sub z} , using vector magnetograms from the Hinode Solar Optical Telescope (SOT). The spatial distribution of j{sub z} has a zebra pattern of strong positive and negative values owing to the penumbral fibril structure resolved by Hinode/SOT. This zebra pattern is due to the derivative of the horizontal magnetic field across the thin fibrils; therefore, it is strong and masks weaker currents that might be present, for example, as a result of the twist of the sunspot. We decompose j{sub z} into the contribution due to the derivatives along and across the direction of the horizontal field, which follows the fibril orientation closely. The map of the tangential component has more distributed currents that are coherent with the chromospheric and coronal twisted structures. Moreover, it allows us to map and identify the direct and return currents in the sunspots. Finally, this decomposition of j{sub z} is general and can be applied to any vector magnetogram in order to better identify the weaker large-scale currents that are associated with coronal twisted/sheared structures.

  12. Comparison of New and Old Sunspot Number Time Series

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.

    2016-11-01

    Four new sunspot number time series have been published in this Topical Issue: a backbone-based group number in Svalgaard and Schatten ( Solar Phys., 2016; referred to here as SS, 1610 - present), a group number series in Usoskin et al. ( Solar Phys., 2016; UEA, 1749 - present) that employs active day fractions from which it derives an observational threshold in group spot area as a measure of observer merit, a provisional group number series in Cliver and Ling ( Solar Phys., 2016; CL, 1841 - 1976) that removed flaws in the Hoyt and Schatten ( Solar Phys. 179, 189, 1998a; 181, 491, 1998b) normalization scheme for the original relative group sunspot number (RG, 1610 - 1995), and a corrected Wolf (international, RI) number in Clette and Lefèvre ( Solar Phys., 2016; SN, 1700 - present). Despite quite different construction methods, the four new series agree well after about 1900. Before 1900, however, the UEA time series is lower than SS, CL, and SN, particularly so before about 1885. Overall, the UEA series most closely resembles the original RG series. Comparison of the UEA and SS series with a new solar wind B time series (Owens et al. in J. Geophys. Res., 2016; 1845 - present) indicates that the UEA time series is too low before 1900. We point out incongruities in the Usoskin et al. ( Solar Phys., 2016) observer normalization scheme and present evidence that this method under-estimates group counts before 1900. In general, a correction factor time series, obtained by dividing an annual group count series by the corresponding yearly averages of raw group counts for all observers, can be used to assess the reliability of new sunspot number reconstructions.

  13. 3-D Structure of Sunspots using Imaging Spectroscopy

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, K. S.; Gary, G. Allen; Reardon, K.

    2006-01-01

    We use the Interferometric BIdimensional Spectrometer (IBIS) of the INAF/Arcetri Astrophysical Observatory and installed at the National Solar Observatory (NSO) Dunn Solar Telescope, to understand the structure of sunspots. Using the spectral lines FeI 6301.5 A, FeII 7224.4 A, and CaII 8542.6 A, we examine the spectroscopic variation of sunspot penumbral and umbral structures at the heights of formation of these lines. These high resolution observations were acquired on 2004 July 30-31, of active region NOAA 10654, using the high order NSO adaptive optics system. We map the spatio-temporal variation of Doppler signatures in these spectral lines, from the photosphere to the chromosphere. From a 70-minute temporal average of individual 32-second cadence Doppler observations we find that the averaged velocities decrease with height, about 3.5 times larger in the deeper photosphere (FeII 7224.4 A; height-of-formation approx. 50 km) than in the upper photosphere FeI 6301.5 A; height-of-formation approx. 350 km), There is a remarkable coherence of Doppler signals over the height difference of 300 km. From a high-speed animation of the Doppler sequence we find evidence for what appears to be ejection of high speed gas concentrations from edges of penumbral filaments into the surrounding granular photosphere. The Evershed flow persists a few arcseconds beyond the traditionally demarcated penumbra-granulation boundary. We present these and other results and discuss the implications of these measurements for sunspot models.

  14. Cyclic and Long-Term Variation of Sunspot Magnetic Fields

    DTIC Science & Technology

    2014-10-15

    Vehicles Directorate 3550 Aberdeen Avenue SE Kirtland AFB, NM 87117-5776 8. PERFORMING ORGANIZATION REPORT NUMBER AFRL -RV-PS-TP-2014-0009 9...1 cy AFRL /RVIL Kirtland AFB, NM 87117-5776 2 cys Official Record Copy AFRL /RVBXS/Dr. Carl Henney 1 cy Approved for public release; distribution... AFRL -RV-PS- TP-2014-0009 AFRL -RV-PS- TP-2014-0009 CYCLIC AND LONG-TERM VARIATION OF SUNSPOT MAGNETIC FIELDS Alexei A. Pevtsov, et al. 15

  15. 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.

  16. Sunspot numbers based on historic records in the 1610s: Early telescopic observations by Simon Marius and others

    NASA Astrophysics Data System (ADS)

    Neuhäuser, R.; Neuhäuser, D. L.

    2016-07-01

    , Tanner, Perovius, Argoli, and Wely are not mentioned as observers for 1611, 1612, 1618, 1620, and 1621 in Hoyt & Schatten. Marius and Schmidnerus are among the earliest datable telescopic sunspot observers (1611 Aug 3, Julian), namely after Harriot, the two Fabricius (father and son), Scheiner, and Cysat. Sunspots records by Malapert from 1618 to 1621 show that the last low-latitude spot was seen in Dec 1620, while the first high-latitude spots were noticed in June and Oct 1620, so that the Schwabe cycle turnover (minimum) took place around that time, which is also consistent with the sunspot trend mentioned by Marius and with naked-eye spots and likely true aurorae. We consider discrepancies in the Hoyt & Schatten (1998) systematics, we compile the active day fractions for the 1610s, and we critically discuss very recent publications on Marius which include the following Maunder Minimum. Our work should be seen as a call to go back to the historical sources.

  17. Magnetometeorology: Relationships between the weather and the earth's magnetic field. [solar cycle effects on length of growing season

    NASA Technical Reports Server (NTRS)

    King, J. W.; Willis, D. M.

    1974-01-01

    A comparison of meteorological pressures and the strength of the earth's magnetic field suggests that the magnetic field exerts, through some unknown process, a controlling influence on the average pressure in the troposphere at high latitudes. Changes in the length of the growing season are related to the solar cycle effects on the geomagnetic field. On average, the growing season is about 25 days longer near sunspot maximum than near sunspot minimum. Comparison of growing season and solar data reveals the geophysically interesting fact that the growing season tends to be the longest about a year after sunspot maximum.

  18. Testing the Sunspot Subsurface ("Coffee-Cup") Structure

    NASA Astrophysics Data System (ADS)

    Kosovichev, Alexander G.; Zhao, J.; Parchevsky, K. V.; Hartlep, T.

    2009-05-01

    Helioseismic inferences of the subsurface structure of sunspots have been in the focus of local helioseismology investigations and discussions during the past decade. Initially obtained from the SOHO/MDI high-resolution data using a simple ray-path perturbation theory for inversions of acoustic travel times the results draw significant criticism and concerns, but, in general, have been confirmed by subsequent measurements and inversions. Nevertheless, because of the complexity of the wave excitation and propagation in the subsurface layers there are still potential systematic uncertainties that must be resolved. Recently developed 3D simulations of MHD waves provide an important tool for the verification and testing of local helioseismology results. However, the use of the simulations is not as straightforward as originally thought. In particular, we present results of testing of the time-distance helioseismology measurement and inversion procedures for sound-speed perturbations modeling the sunspot subsurface structure, and discuss the limitations and uncertainties of the simulations and helioseismic inferences.

  19. Lateral Downflows in Sunspot Penumbral Filaments and their Temporal Evolution

    NASA Astrophysics Data System (ADS)

    Esteban Pozuelo, S.; Bellot Rubio, L. R.; de la Cruz Rodríguez, J.

    2015-04-01