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Sample records for 11-year sunspot cycle

  1. Relationship between the north-south asymmetry of sunspot formation and the amplitude of 11-year solar activity cycles

    NASA Astrophysics Data System (ADS)

    Latyshev, S. V.; Olemskoy, S. V.

    2016-07-01

    A relationship between the north-south asymmetry of sunspot formation and the amplitude of 11-year cycles has been established from the RGO/USAF/NOAA data on sunspots. It is shown that the higher the solar cycle amplitude, the smaller the absolute value of the north-south asymmetry. The revealed pattern has been investigated in a numerical dynamo model with irregular variations of the alpha-effect.

  2. 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.

  3. The 11-year cycle in human births

    NASA Astrophysics Data System (ADS)

    Randall, Walter; Moos, Walter S.

    1993-06-01

    The annual numbers of human births were analyzed with regard to an 11-year cycle. The annual values were obtained from seven different regions: Australia, Germany, England and Wales, New Zealand, Japan, Switzerland, and the USA. Fifty-five annual values were obtained from each region for the years 1930 to 1984, comprising approximately five sunspot cycles. For each region the annual values were formed into 5 by 11 matrices; the eleven column means obtained were standardized, and plotted. A periodic regression technique, utilizing the fitting functions of the Fourier series, was used to evaluate the temporal order in the column means. Eleven-year rhythms were found and compared with solar and geophysical variables. Correlations were found with sunspots and solar flares, with terrestrial measures of magnetic disturbances (the magnetic indices derived from the K-index), and with temperature. The correlation of conceptions with the 11-year solar cycle may be a potential guide in the selection of further variables for the control and regulation of the rhythms in human conceptions.

  4. Group Sunspot Numbers: Sunspot Cycle Characteristics

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.; Wilson, R. M.; Reichmann, E. J.; Six, N. Frank (Technical Monitor)

    2002-01-01

    We examine the "Group" sunspot numbers constructed by Hoyt and Schatten to determine their utility in characterizing the solar activity cycle. We compare smoothed monthly Group Sunspot Numbers to Zurich (International) Sunspot Numbers, 10.7-cm radio flux, and total sunspot area. We find that the Zurich numbers follow the 10.7-cm radio flux and total sunspot area measurements slightly better than the Group numbers. We examine several significant characteristics of the sunspot cycle using both Group numbers and Zurich numbers. We find that the "Waldmeier Effect" - the anti-correlation between cycle amplitude and the elapsed time between minimum and maximum of a cycle - is much more apparent in the Zurich numbers. The "Amplitude-Period Effect" the anti-correlation between cycle amplitude and the length of the previous cycle from minimum to minimum - is also much more apparent in the Zurich numbers. The "Amplitude-Minimum Effect" - the correlation between cycle amplitude and the activity level at the previous (onset) minimum is equally apparent in both the Zurich numbers and the Group numbers. The "Even-Odd Effect" - in which odd-numbered cycles are larger than their even-numbered precursors - is somewhat stronger in the Group numbers but with a tighter relationship in the Zurich numbers. The "Secular Trend" - the increase in cycle amplitudes since the Maunder Minimum - is much stronger in Group numbers. After removing this trend we find little evidence for multi-cycle periodicities like the 80 year Gleissberg cycle or the two- and three-cycle periodicities. We also find little evidence for a correlation between the amplitude of a cycle and its period or for a bimodal distribution of cycle periods. We conclude that the Group numbers are most useful for extending the sunspot cycle data further back in time and thereby adding more cycles and improving the statistics. However, the Zurich numbers are more useful for characterizing the on-going levels of solar activity.

  5. 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

  6. A comparative look at sunspot cycles

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1984-01-01

    On the basis of cycles 8 through 20, spanning about 143 years, observations of sunspot number, smoothed sunspot number, and their temporal properties were used to compute means, standard deviations, ranges, and frequency of occurrence histograms for a number of sunspot cycle parameters. The resultant schematic sunspot cycle was contrasted with the mean sunspot cycle, obtained by averaging smoothed sunspot number as a function of time, tying all cycles (8 through 20) to their minimum occurence date. A relatively good approximation of the time variation of smoothed sunspot number for a given cycle is possible if sunspot cycles are regarded in terms of being either HIGH- or LOW-R(MAX) cycles or LONG- or SHORT-PERIOD cycles, especially the latter. Linear regression analyses were performed comparing late cycle parameters with early cycle parameters and solar cycle number. The early occurring cycle parameters can be used to estimate later occurring cycle parameters with relatively good success, based on cycle 21 as an example. The sunspot cycle record clearly shows that the trend for both R(MIN) and R(MAX) was toward decreasing value between cycles 8 through 14 and toward increasing value between cycles 14 through 20. Linear regression equations were also obtained for several measures of solar activity.

  7. The 11-year solar cycle continues during prolonged sunspot minima

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-12-01

    Streaming into the solar system at nearly the speed of light, galactic cosmic rays (GCRs) are a high-energy mix of protons, electrons, and atomic nuclei. As they pass into reach of the outflowing solar wind, the propagation of GCRs is inhibited. Galactic cosmic rays that make it to Earth interact with the atmosphere, creating a shower of heavy isotopes including beryllium-10. Beryllium-10 isotope concentrations recorded in ice cores provide a long-term, high temporal resolution record of galactic cosmic ray flux.

  8. Prediction Methods in Solar Sunspots Cycles

    NASA Astrophysics Data System (ADS)

    Ng, Kim Kwee

    2016-02-01

    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.

  9. 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

  10. Prediction Methods in Solar Sunspots Cycles.

    PubMed

    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

  11. Solar Cycle Predictions Near Sunspot Minimum

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    1997-01-01

    Observations of solar magnetic activity and the dynamics of the solar convection zone have produced severe constraints on models of the Sun's magnetic dynamo. These constraints are so severe that, at present, we do not have numerical models that can accept the current conditions and then march forward in time to predict future activity. Given this state of solar dynamo theory we are forced to examine previous behavior to discover patterns and trends that afford us some measure of predictability. Here we examine the behavior of several indicators of solar activity near solar minimum that are well correlated with the amplitude of the following solar maximum to predict the level of solar activity over cycle 23. Sunspot numbers, areas, and positions are useful for characterizing solar cycle behavior due to the extent of the data (12 cycles or more). These data exhibit several patterns that relate future activity to past behavior. With the Odd-Even effect the odd numbered cycles have been larger than their even numbered predecessors for each of the last six cycle pairs. With the Amplitude-Period effect short period cycles have been followed by large amplitude cycles and long period cycles have been followed by small amplitude cycles for 10 of the last 13 cycles. With the Maximum-Minimum effect the sunspot number at minimum is directly correlated with the sunspot number at maximum for a given cycle. The geomagnetic indices aa and Ap are also related to solar activity by the connections between disturbances in the solar wind and variations in the Earth's magnetic field. Like the Maximum-Minimum effect for sunspots, the size of the aa and Ap indices at minimum are directly related to the amplitude of the following maximum. The number of geomagnetically disturbed days (days with Ap >= 25) over the course of a cycle is another indicator for the size of the next cycle. The aa and Ap indices can each be separated into a component in phase with the current sunspot cycle and an

  12. Description of sunspot cycles by orthogonal functions

    NASA Astrophysics Data System (ADS)

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

    1984-10-01

    Based on the principal component analysis technique and evidence for a 22-yr double-sunspot cycle periodicity. The time series of sunspot numbers is represented as a sum of mutually orthogonal eigenvectors in the time domain. It is shown that the first two eigenvectors account for about 90 percent of the cumulative 'signal power,' and that this is sufficient for reconstruction of the raw data curve. It is also noted that the second eigenvector behaves as the time derivative of the first, and that a phase-plane plot of these eigenvectors (i.e. a plot of a variable vs. its rate of change) suggests that the sun's sunspot cycle is driven by an oscillator; the implication is that, embedded within the sun, a chronometer is at work (e.g. Dicke, 1979).

  13. Description of sunspot cycles by orthogonal functions

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Based on the principal component analysis technique and evidence for a 22-yr double-sunspot cycle periodicity. The time series of sunspot numbers is represented as a sum of mutually orthogonal eigenvectors in the time domain. It is shown that the first two eigenvectors account for about 90 percent of the cumulative 'signal power,' and that this is sufficient for reconstruction of the raw data curve. It is also noted that the second eigenvector behaves as the time derivative of the first, and that a phase-plane plot of these eigenvectors (i.e. a plot of a variable vs. its rate of change) suggests that the sun's sunspot cycle is driven by an oscillator; the implication is that, embedded within the sun, a chronometer is at work (e.g. Dicke, 1979).

  14. 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.

  15. 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.

  16. Relativistic electrons in the outer-zone: An 11 year cycle, their relation to the solar wind

    SciTech Connect

    Belian, R.D.; Cayton, T.E.; Christensen, R.A.; Ingraham, J.C.; Meier, M.M.; Reeves, G.D.; Lazarus, A.J.

    1994-12-31

    We examine Los Alamos energetic electron data from 1979 through the present to show long term trends in the trapped relativistic electron populations at geosynchronous-earth-orbit (GEO). Data is examined from several CPA and SOPA instruments to cover the interval from 1979 through June 1994. It is shown that the higher energy electrons fluxes (E > 300 keV) displayed a cycle of {approx}11 years. In agreement with other investigators, we also show that the relativistic electron cycle is out of phase with the sunspot cycle. We compare the occurrences of relativistic electrons and solar wind high speed streams and determine that on the time scale of 15 years the two do not correlate well. The long-term data set we provide here shows a systematic change of the electron energy spectrum during the course of the solar cycle. This information should be useful to magnetospheric scientists, model designers and space flight planners.

  17. 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.

  18. 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

  19. On the average rate of growth in sunspot number and the size of the sunspot cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1990-01-01

    The average rate of growth in sunspot number over selected time intervals and the maximum average value as they both relate to the size of the cycle are examined, in order to predict the size of cycle 22. The predictions are compared with those of Wilson (1990) to determine whether a consensus is apparent. The average rate of growth during the ascending portion of the sunspot cycle, defined as the difference in smoothed sunspot number values between elapsed time t and sunspot minimum divided by t, is shown to correlate with the size of the sunspot cycle, especially for t greater or equal to 18 months. The maximum value of the average rate of growth is also shown to highly correlate (r = 0.98) with the size of the cycle. Using 4.5 as the maximum value of the average rate of growth, a lower limit for R(M) is estimated. The results show that the findings are consistent with the previous single variate predictions for R(M) for cycle 22.

  20. A prediction for the size of sunspot cycle 22

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1988-01-01

    Based on 'annual' averages, a bivariate analysis of the maximum amplitude of the sunspot cycle against its minimum amplitude and the minimum value of the aa geomagnetic index (in the vicinity of sunspot cycle minimum) results in a fit that closely matches the observable record. The bilinear fit has a high coefficient of correlation (r = 0.982) and a small standard deviation (s = 9.5), suggesting that it may be useful for predicting the size of a sunspot cycle 3 to 4 years before maximum amplitude occurrence. Applying the fit to cycle 22, the annual average of maximum amplitude is found to be 92 + or - 19 (equivalent to 96 + or - 20 in terms of the 13-month running mean or smoothed sunspot number).

  1. Sunspot time series - Spectrum from square law modulation of the Hale cycle

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.

    1982-01-01

    The spectrum of the sunspot index can be qualitatively accounted for by a very simple time series model which the Hale 22 year cycle dominates; the series is amplitude modulated at the 90 year Gleissberg period with an index of 25%. The square of the modulated Hale cycle reproduces all of the spectral lines of the Zurich sunspot index spectrum, provided that a small offset is included in the Hale carrier. Without this, evidence of the 22 year periodicity disappears. The squaring explains the dominance of the 11 year cycle which is an artifact of the modulation as is the 45 year line. The offset suggests a small relict magnetic field in the sun's core. Lastly Gilliland (1981) finds a radial eigenmode in the sun with period of 76 + or - 8 years suggestive of a physical basis for the Gleissberg modulation.

  2. Relativistic electrons in the outer-zone: An 11 year cycle; Their relation to the solar wind

    SciTech Connect

    Belian, R.D.; Cayton, T.E.; Christensen, R.A.; Ingraham, J.C.; Meier, M.M.; Reeves, G.D.; Lazarus, A.J.

    1996-07-01

    We examine Los Alamos energetic electron data from 1979 through the present to show long term trends in the trapped relativistic electron populations at geosynchronous-earth-orbit (GEO). Data is examined from several CPA and SOPA instruments to cover the interval from 1979 through June, 1994. It is shown that the higher energy electrons fluxes ({ital E}{gt}300 keV) displayed a cycle of {approx_equal}11 years. In agreement with other investigators, we also show that the relativistic electron cycle is out of phase with the sunspot cycle. We compare the occurrences of relativistic electrons and solar wind high speed streams and determine that on the time scale of 15 years the two do not correlate well. The long-term data set we provide here shows a systematic change of the electron energy spectrum during the course of the solar cycle. This information should be useful to magnetospheric scientists, model designers and space flight planners. {copyright} {ital 1996 American Institute of Physics.}

  3. 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.

  4. 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.

  5. A Bayesian Analysis of the Correlations Among Sunspot Cycles

    NASA Astrophysics Data System (ADS)

    Yu, Y.; van Dyk, D. A.; Kashyap, V. L.; Young, C. A.

    2012-12-01

    Sunspot numbers form a comprehensive, long-duration proxy of solar activity and have been used numerous times to empirically investigate the properties of the solar cycle. A number of correlations have been discovered over the 24 cycles for which observational records are available. Here we carry out a sophisticated statistical analysis of the sunspot record that reaffirms these correlations, and sets up an empirical predictive framework for future cycles. An advantage of our approach is that it allows for rigorous assessment of both the statistical significance of various cycle features and the uncertainty associated with predictions. We summarize the data into three sequential relations that estimate the amplitude, duration, and time of rise to maximum for any cycle, given the values from the previous cycle. We find that there is no indication of a persistence in predictive power beyond one cycle, and we conclude that the dynamo does not retain memory beyond one cycle. Based on sunspot records up to October 2011, we obtain, for Cycle 24, an estimated maximum smoothed monthly sunspot number of 97±15, to occur in January - February 2014 ± six months.

  6. On the existence of the 11-year cycle in solar activity before the Maunder minimum

    SciTech Connect

    Attolini, M.R.; Cecchini, S.; Cini Castagnoli, G.; Galli, M.; Nanni, T.

    1988-11-01

    The existence of the 11-year cycle in solar activity before the Maunder minimum is clearly demonstrated with cosmogenic /sup 10/Be in polar ice during 1180--1500 A.D. For that interval a periodicity of 11.4 +- 0.2 years is found with a high significance level. Indication of a cyclicity that resembles the Hale magnetic cycle is also observed at a lower significance level. A highly variable cyclicity in the band 9.5--11.5 years is also found in the record of historical aurorae which appears to be well correlated with the /sup 10/Be cyclicity for the same time interval. It is concluded that the Schwabe, or 11-year, cycle and the Hale magnetic cycle were present before and after the Maunder minimum, even though it is not possible to understand the variability of the cycle. copyright American Geophysical Union 1988

  7. Are climatological correlations with the Hale double sunspot cycle meaningful?

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    A sunspot cycle which may have been subject to a predicted phase reversal between 1800 and 1880 A. D is discussed. Several climatological parameters normally correlated with this cycle are examined and do not exhibit a corresponding phase reversal during this period. It is proposed that this apparent discrepancy can be resolved by suitable observations during the upcoming half decade.

  8. 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.

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

    DOE PAGESBeta

    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 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

  10. Nighttime morphology of vertical plasma drifts at Ouagadougou during different seasons and phases of sunspot cycles 20-22

    NASA Astrophysics Data System (ADS)

    Adebesin, B. O.; Rabiu, A. B.; Adeniyi, J. O.; Amory-Mazaudier, C.

    2015-11-01

    The nighttime morphology of vertical plasma drift (Vd) inferred from ground-based measurements of the F layer height at Ouagadougou (12.4°N, 358.6°E) in the African Equatorial Ionization Anomaly trough was investigated. The observation covers four seasons, four sunspot cycle phases, annual, and 11 year sunspot cycle (SC) variations of the SCs 20-22 spanning 1966-1998 and a first attempt of such study. The annual mean peak magnitudes of Vd during the prereversal enhancement (PRE) and minimum reversal periods exhibit the 11 year sunspot cycle evolution with the sunspot number (Rz). The PRE peak/Rz and reversal peak/Rz relationships are 98.7% and 84.8%, respectively. PRE peak in June solstice appears 1 h later than for other seasons and is attributed to a decrease in the equatorial zonal wind/conductivity gradient. The highest PRE magnitude and downward perturbation drifts near dusk appear during the equinoxes and lowest in June solstice for all cycles. There is semiannual asymmetry in the variation of Vd during all cycles of the PRE event with peaks in March and September/October. A remarkable feature is the consistent local presunrise drift enhancement for two SCs 20 and 21, which is not a regular feature of the equatorial ionosphere. The rate of inhibition of scintillation effect increases with decreasing phase of sunspot activity and maximizes during the solstices. Both the PRE and minimum reversal peak magnitudes are influenced by the phase of sunspot cycle. Ouagadougou data in this study had shown reliable drift characteristics and can be integrated into the African regional empirical drift model.

  11. 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.

  12. 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

  13. 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.

  14. Amplifying the Pacific climate system response to a small 11-year solar cycle forcing.

    PubMed

    Meehl, Gerald A; Arblaster, Julie M; Matthes, Katja; Sassi, Fabrizio; van Loon, Harry

    2009-08-28

    One of the mysteries regarding Earth's climate system response to variations in solar output is how the relatively small fluctuations of the 11-year solar cycle can produce the magnitude of the observed climate signals in the tropical Pacific associated with such solar variability. Two mechanisms, the top-down stratospheric response of ozone to fluctuations of shortwave solar forcing and the bottom-up coupled ocean-atmosphere surface response, are included in versions of three global climate models, with either mechanism acting alone or both acting together. We show that the two mechanisms act together to enhance the climatological off-equatorial tropical precipitation maxima in the Pacific, lower the eastern equatorial Pacific sea surface temperatures during peaks in the 11-year solar cycle, and reduce low-latitude clouds to amplify the solar forcing at the surface. PMID:19713524

  15. [Unevenness of distribution of historical events throughout an 11-year solar cycle].

    PubMed

    Putilov, A A

    1992-01-01

    Tchizhevsky hypothesis (1922) of historical process heliotaraxia (helios--sun, taracsio--perturb) was empirically tested. Samples of near 13 and 4.6 thousand events mentioned in Chronology sections of two largest Soviet historical handbooks were analyzed. Events were classified into 4 groups on the basis of "strength" and "social contradictions meaning" of their names, called tolerance and polarity: tolerant--intolerant (e.f. riot--roform) and polar--neutral (e.f. civil war-external war). It was found that frequency and polarity of historical events increased in maximum of sunspot cycle and in the next year as compared with minimum and the year before minimum. The probability of revolution (the most polar and intolerant name of historical event) is the highest in maximum and the lowest in the year before minimum. Intolerance of polar events increased and neutral events decreased in maximum. All these relations were highly significant (P < 0.001). It was concluded that heliotaraxic phenomena exist and are basically associated with year of sunspot maximum. PMID:1420416

  16. 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.

  17. Evidence for climate variations induced by the 11-year solar and cosmic rays cycles

    NASA Astrophysics Data System (ADS)

    Bruckman, William; Ramos, Elio

    2010-02-01

    We analyzed data from PSMSL monthly mean sea level seeking correlations between sea level fluctuations and the solar and cosmic rays 11 year cycle. The data reveals decadal variability that could be causally connected to the solar and cosmic rays cycle, since these periodic changes are correlated. It is also found that the solar (cosmic rays) cycle correlates (anti-correlates) with the mean global surface temperature anomaly. A probable explanation of the above correlations is that the solar intensity and cosmic rays variations induce oscillations in the average temperature and precipitation, with corresponding changes in the continental water and snow accumulation. Thus, for instance, a higher than average snow and water over land, and lower temperatures produce oceans thermal contraction and lower mass, implicating lower mean sea level.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Three-halves law in sunspot cycle shape

    NASA Astrophysics Data System (ADS)

    Bracewell, R. N.

    1988-02-01

    Annual mean sunspot numbers R(t) since 1700 show evidence of a non-linear effect, first evidenced by the detection of a third harmonic in R±(t), the alternating representation of the magnetic (22 yr) cycle of solar activity. The form of the non-linearity proves to be a three-halves law R(t) = 100[|Rlin(t)|/83]3/2, where Rlin(t), also an alternating quantity, is a presumed underlying or "linearized" sunspot number. The non-linearity is of such a nature as to cause strong semicycles to be sharper than sinusoidal and to produce the inflexion in R±(t) noted at sunspot minimum. The difference R(t)-|Rlin(t)| is sufficiently like a third harmonic, for semicycles of average strength, to explain the band around 22/3 yr which is noticeable in the spectrum of R±(t). However, the third harmonic alone is not sufficient to account for the observed dependence of semicycle shape on amplitude, whereas the three-halves law accounts economically for a range of effects. A physical explanation of a three-halves law is given.

  3. 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.

  4. On the Relationship Between Spotless Days and the Sunspot Cycle: A Supplement

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    This study provides supplemental material to an earlier study concerning the relationship between spotless days and the sunspot cycle. Our previous study, Technical Publication (TP)-2005-213608 determined the timing and size of sunspot minimum and maximum for the new sunspot cycle, relative to the occurrence of the first spotless day during the declining phase of the old sunspot cycle and the last spotless day during the rising portion of the new cycle. Because the number of spotless days (NSD) rapidly increases as the cycle nears sunspot minimum and rapidly decreases thereafter, the size and timing of sunspot minimum and maximum might be more accurately determined using a higher threshold for comparison, rather than using the first and last spotless day occurrences. It is this aspect that is investigated more thoroughly in this TP.

  5. Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles

    NASA Astrophysics Data System (ADS)

    Rybak, Aleksey

    2016-06-01

    This paper considers a longitude distribution of sunspot groups over 1982-2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30-40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to Malde classification indices throughout the observation period. The longitude distribution of large sunspot groups made in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.

  6. 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.

  7. The response of chemistry and climate to the 11-year solar cycle in UM-UKCA

    NASA Astrophysics Data System (ADS)

    Bednarz, Ewa; Telford, Paul; Maycock, Amanda; Abraham, Luke; Braesicke, Peter; Pyle, John

    2014-05-01

    It is now generally agreed that the UV variability associated with the 11-year solar cycle leads to changes in ozone and temperature in the upper stratosphere. In addition, a range of observational and modelling studies suggest that such changes are the starting point for a chain of processes (including feedbacks) resulting in circulation changes in many areas of the atmosphere. However, precise details of the interactions between chemistry and meteorology induced by solar variability remain under question. In our study, we use a version of the UM-UKCA chemistry-climate model with consistent spectrally-resolved solar variability. While the solar cycle in heating rates has been applied with the method used in HadGEM2-ES, fine spectrally-resolved solar variability has been uniquely incorporated into the Fast-JX photolysis scheme. We perform two 50-year-long perpetual year solar maximum and solar minimum integrations and complement them with a three member ensemble of a transient 1960-2010 integration in which boundary conditions correspond by and large to the CCMI Ref-C1 scenario. We show how the inferred solar signals vary between the individual experiments. This indicates high natural variability and the resulting contamination of the solar signal with contributions from other processes as well as the existence of possible non-linearities between the solar cycle and other atmospheric forcings. Therefore, we highlight that long data series are needed to ensure correct attribution of the modelled and observed anomalies. In addition, we present results from two perpetual year experiments in which the solar cycle was applied exclusively in either short-wave heating or photolysis. We find large non-linearities in the modelled anomalies as compared to the realistic integration with both modulations included. This highlights the subtle nature of the dynamical response to the solar cycle forcing and indicates the need for interactive chemistry with a detailed photolysis

  8. 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.

  9. The 11 year solar cycle signature on wave-driven dynamics in WACCM

    NASA Astrophysics Data System (ADS)

    Cullens, Chihoko Y.; England, Scott L.; Garcia, Rolando R.

    2016-04-01

    This study describes the influence of the 11 year solar cycle on gravity waves and the wave-driven circulation, using an ensemble of six simulations of the period from 1955 to 2005 along with fixed solar maximum and minimum simulations of the Whole Atmospheric Community Climate Model (WACCM). Solar cycle signals are estimated by calculating the difference between solar maximum and minimum conditions. Simulations under both time-varying and fixed solar inputs show statistically significant responses in temperatures and winds in the Southern Hemisphere (SH) during austral winter and spring. At solar maximum, the monthly mean, zonal mean temperature in the SH from July to October is cooler (~1-3 K) in the stratosphere and warmer (~1-4 K) in the mesosphere and the lower thermosphere (MLT). In solar maximum years, the SH polar vortex is more stable and its eastward speed is about 5-8 m s-1 greater than during solar minimum. The increase in the eastward wind propagates downward and poleward from July to October in the SH. Because of increase in the eastward wind, the propagation of eastward gravity waves to the MLT is reduced. This results in a net westward response in gravity wave drag, peaking at ~10 m s-1 d-1 in the SH high-latitude MLT. These changes in gravity wave drag modify the wave-induced residual circulation, and this contributes to the warming of ~1-4 K in the MLT.

  10. Coronal holes and solar wind streams during the sunspot cycle

    NASA Technical Reports Server (NTRS)

    Sheeley, N. R., Jr.

    1992-01-01

    Complementary synoptic observations of the Sun and interplanetary space have been obtained nearly continuously for more than two sunspot cycles and have led to new ideas about the origin of the solar wind. These observations show an inverse correlation between wind speed at Earth and magnetic flux tube expansion in the corona, with fast wind originating from slowly diverging tubes and vice versa. Although this result is consistent with the Skylab-era concept that fast wind originates from the center of a large isolated coronal hole, it implies that the wind may be even faster at the facing edges of like-polarity holes where the flux-tubes converge as they begin their outward extension. Thus, very fast wind ought to originate from the high-latitude edges of the circumpolar holes soon after sunspot maximum and from the mid-latitude necks of the polar-hole lobes during the declining phase of the cycle. The observed inverse correlation may be understood physically in terms of a model in which Alfven waves boost the wind to high speed provided that the wave energy flux is distributed approximately uniformly at the coronal base.

  11. Understanding the 11-year Solar Cycle Signal in Stratospheric Ozone using a 3D CTM

    NASA Astrophysics Data System (ADS)

    Dhomse, Sandip; Chipperfield, Martyn; Feng, Wuhu

    2014-05-01

    The exact structure of the 11-year solar cycle signal in stratospheric ozone is still an open scientific question. Long-term satellite data such as Stratospheric Aerosol and Gas Experiment (SAGE) and Solar Backscatter UltraViolet (SBUV) show a positive solar response in the tropical lower stratosphere and upper stratosphere/lower mesosphere (US/LM), but a negligible signal in the tropical middle stratosphere. On the other hand, Halogen Occultation Experiment (HALOE) measurements show a positive signal in the lower and middle stratosphere and smaller solar signal in the tropical US/LM. Currently most chemical models are able to simulate a "double-peak"-structured solar signal but the model simulated solar signals tend to show better agreement with the HALOE-derived solar signal than those from SBUV or SAGE measurements. Also, some recent studies argue that due to the significantly different solar variability during the recent solar cycle (23), the solar signal in the US/LM ozone is negative (out of phase with total solar irradiance changes) for this later period compared to previous solar cycles. We have used 3-D chemical transport model (CTM) simulations to better understand the possible mechanisms responsible for this discrepancy. Various model simulations have been performed for 1979-2012 time period using ERA-Interim meteorological fields as a dynamical forcing. Model output is sampled at collocated measurement points for three satellite instruments performing stratospheric ozone measurements using the solar occultation technique: SAGE II (1984-2005), HALOE (1992-2005) and Atmospheric Chemistry Experiment (ACE, 2003-present). Overall the modelled ozone shows good agreement with all the data sets. However, in the US/LM, modelled ozone anomalies are better correlated with HALOE and ACE than SAGE II measurements. Hence the modelled solar signal in the stratospheric and lower mesospheric ozone also shows better agreement with the solar signal derived using HALOE and

  12. 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.

  13. 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.

  14. 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.

  15. Measurements of sunspot group tilt angles for solar cycles 19-24

    NASA Astrophysics Data System (ADS)

    Isik, Seda; Isik, Emre

    2016-07-01

    The tilt angle of a sunspot group is a critical quantity in the surface transport magnetic flux on global scales, playing a role in the solar dynamo. To investigate Joy's law for four cycles, we measured the tilt angles of sunspot groups for solar cycles 19-24. We have developed an IDL routine, which allows the user to interactively select and measure sunspot positions and areas on the solar disc, using the sunspot drawing database of Kandilli Observatory. The method is similar to that used by others in the literature, with the exception that sunspot groups were identified manually, which has improved the accuracy of the tilt angles. We present cycle averages of the tilt angle and compare the results with the existing data in the literature.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. The unusual minimum of sunspot cycle 23 caused by meridional plasma flow variations.

    PubMed

    Nandy, Dibyendu; Muñoz-Jaramillo, Andrés; Martens, Petrus C H

    2011-03-01

    Direct observations over the past four centuries show that the number of sunspots observed on the Sun's surface varies periodically, going through successive maxima and minima. Following sunspot cycle 23, the Sun went into a prolonged minimum characterized by a very weak polar magnetic field and an unusually large number of days without sunspots. Sunspots are strongly magnetized regions generated by a dynamo mechanism that recreates the solar polar field mediated through plasma flows. Here we report results from kinematic dynamo simulations which demonstrate that a fast meridional flow in the first half of a cycle, followed by a slower flow in the second half, reproduces both characteristics of the minimum of sunspot cycle 23. Our model predicts that, in general, very deep minima are associated with weak polar fields. Sunspots govern the solar radiative energy and radio flux, and, in conjunction with the polar field, modulate the solar wind, the heliospheric open flux and, consequently, the cosmic ray flux at Earth. PMID:21368827

  6. Modulation of the Arctic Oscillation and the East Asian winter climate relationships by the 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Zhou, Qun

    2012-03-01

    The modulation of the relationship between the Arctic Oscillation (AO) and the East Asian winter climate by the 11-year solar cycle was investigated. During winters with high solar activity (HS), robust warming appeared in northern Asia in a positive AO phase. This result corresponded to an enhanced anticyclonic flow at 850 hPa over northeastern Asia and a weakened East Asian trough (EAT) at 500 hPa. However, during winters with low solar activity (LS), both the surface warming and the intensities of the anticyclonic flow and the EAT were much less in the presence of a positive AO phase. The possible atmospheric processes for this 11-year solar-cycle modulation may be attributed to the indirect influence that solar activity induces in the structural changes of AO. During HS winters, the sea level pressure oscillation associated with the AO became stronger, with the significant influence of AO extending to East Asia. In the meantime, the AO-related zonal-mean zonal winds tended to extend more into the stratosphere during HS winters, which implies a stronger coupling to the stratosphere. These trends may have led to an enhanced AO phase difference; thus the associated East Asian climate anomalies became larger and more significant. The situation tended to reverse during LS winters. Further analyses revealed that the relationship between the winter AO and surface-climate anomalies in the following spring is also modulated by the 11-year solar cycle, with significant signals appearing only during HS phases. Solar-cycle variation should be taken into consideration when the AO is used to predict winter and spring climate anomalies over East Asia.

  7. Evidence that a Deep Meridional Flow Sets the Sunspot Cycle Period

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Nandy, D.; Wilson, R. M.; Reichmann, E. J.

    2003-01-01

    Sunspots appear on the Sun in two bands on either side of the equator that drift toward lower latitudes as each sunspot cycle progresses. We examine the equatorward drift of the centroid of the sunspot area in each hemisphere from 1874 to 2002 and find that the drift rate slows as the centroid approaches the equator. We compare the drift rate at sunspot cycle maximum to the cycle-period for each hemisphere and find a highly significant anti-correlation: hemispheres with faster drift rates have shorter periods. These observations are. consistent with an equatorward meridional counterflow, deep within the Sun, as the primary driver of the equatorward migration and the period associated with the sunspot cycle. We also find that the drift rate at maximum is significantly correlated with the amplitude of the following cycle, a prediction of dynamo models that employ a deep equatorward meridional flow. Our results indicate an amplitude of about 1.2 m/s for the meridional flow velocity at the base of the solar convection zone.

  8. 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.

  9. New 1982-1990 photometry of Lambda Andromedae and its 11-year cycle

    NASA Technical Reports Server (NTRS)

    Hall, Douglas S.; Henry, Gregory W.; Boehme, Dietmar; Brooks, Peter A.; Chang, Sandy; Dolzan, Ales; Fortier, George L.; Fried, Robert E.; Genet, Russell M.; Grim, Bruce S.

    1991-01-01

    The paper presents photoelectric photometry of Lambda And never before published, obtained between February 1982 and December 1990 at 29 different observatories. Then it is combined with all other photometry available (previously published, contained in the I.A.U. Commission 27 Archives, and obtained with the Vanderbilt 16-inch automatic telescope but not yet published), to yield a 14.8-year data base. Analysis reveals a long-term cycle in mean brightness, with a full range of 0.15 m and a period of 11.4 +/- 0.4 years. Because most of the new photometry was concentrated in the 1983-1984 observing season, this one well-defined light curve is analyzed with a two-spot model. Spot A keeps a 0.04 m amplitude throughout four rotation cycles whereas the amplitude of spot B diminishes from 0.09 m down almost to 0.03 m. The spot rotation periods were 55.9 d +/- 0.6 d and 52.8 d +/- 1.0 d, respectively.

  10. 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.

  11. 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.

  12. SOLAR CYCLE 24: CURIOUS CHANGES IN THE RELATIVE NUMBERS OF SUNSPOT GROUP TYPES

    SciTech Connect

    Kilcik, A.; Yurchyshyn, V. B.; Ozguc, A.; Rozelot, J. P.

    2014-10-10

    Here, we analyze different sunspot group (SG) behaviors from the points of view of both the sunspot counts (SSCs) and the number of SGs, in four categories, for the time period of 1982 January-2014 May. These categories include data from simple (A and B), medium (C), large (D, E, and F), and decaying (H) SGs. We investigate temporal variations of all data sets used in this study and find the following results. (1) There is a very significant decrease in the large groups' SSCs and the number of SGs in solar cycle 24 (cycle 24) compared to cycles 21-23. (2) There is no strong variation in the decaying groups' data sets for the entire investigated time interval. (3) Medium group data show a gradual decrease for the last three cycles. (4) A significant decrease occurred in the small groups during solar cycle 23, while no strong changes show in the current cycle (cycle 24) compared to the previous ones. We confirm that the temporal behavior of all categories is quite different from cycle to cycle and it is especially flagrant in solar cycle 24. Thus, we argue that the reduced absolute number of the large SGs is largely, if not solely, responsible for the weak cycle 24. These results might be important for long-term space weather predictions to understand the rate of formation of different groups of sunspots during a solar cycle and the possible consequences for the long-term geomagnetic activity.

  13. Observations and analysis of the Ionospheric Alfven resonance mode structure in a complete 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Baru, N. A.; Koloskov, A. V.; Yampolsky, Y. M.; Rakhmatulin, R. A.

    2016-03-01

    The long-term data of the ionospheric Alfven resonance (IAR) observations recorded at the Ukrainian Antarctic Station "Akademik Vernadsky" from 2002 to 2013 and at Sayan Solar Observatory (Mondy, Russia) from 2010 to 2013 are analyzed. IAR fine spectral structure is studied and a previously unknown effect of splitting of the several lowest resonance modes is discovered. The diurnal and seasonal dependencies of this effect are investigated as well as the dependences of the probability of IAR and splitting detection on Solar and geomagnetic activities in the 11-year cycle. The morphological features of the splitting frequency behavior are analyzed and three main characteristic periods of the splitting are identified, namely: the development, the stationary period and the disappearing. Possible mechanisms of the splitting effect are suggested.

  14. 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.

  15. Sunspot variation and selected associated phenomena: A look at solar cycle 21 and beyond

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1982-01-01

    Solar sunspot cycles 8 through 21 are reviewed. Mean time intervals are calculated for maximum to maximum, minimum to minimum, minimum to maximum, and maximum to minimum phases for cycles 8 through 20 and 8 through 21. Simple cosine functions with a period of 132 years are compared to, and found to be representative of, the variation of smoothed sunspot numbers at solar maximum and minimum. A comparison of cycles 20 and 21 is given, leading to a projection for activity levels during the Spacelab 2 era (tentatively, November 1984). A prediction is made for cycle 22. Major flares are observed to peak several months subsequent to the solar maximum during cycle 21 and to be at minimum level several months after the solar minimum. Additional remarks are given for flares, gradual rise and fall radio events and 2800 MHz radio emission. Certain solar activity parameters, especially as they relate to the near term Spacelab 2 time frame are estimated.

  16. 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.

  17. Global correlation between surface heat fluxes and insolation in the 11-year solar cycle: The latitudinal effect

    NASA Astrophysics Data System (ADS)

    Volobuev, D. M.; Makarenko, N. G.

    2014-12-01

    Because of the small amplitude of insolation variations (1365.2-1366.6 W m-2 or 0.1%) from the 11-year solar cycle minimum to the cycle maximum and the structural complexity of the climatic dynamics, it is difficult to directly observe a solar signal in the surface temperature. The main difficulty is reduced to two factors: (1) a delay in the temperature response to external action due to thermal inertia, and (2) powerful internal fluctuations of the climatic dynamics suppressing the solar-driven component. In this work we take into account the first factor, solving the inverse problem of thermal conductivity in order to calculate the vertical heat flux from the measured temperature near the Earth's surface. The main model parameter—apparent thermal inertia—is calculated from the local seasonal extremums of temperature and albedo. We level the second factor by averaging mean annual heat fluxes in a latitudinal belt. The obtained mean heat fluxes significantly correlate with a difference between the insolation and optical depth of volcanic aerosol in the atmosphere, converted into a hindered heat flux. The calculated correlation smoothly increases with increasing latitude to 0.4-0.6, and the revealed latitudinal dependence is explained by the known effect of polar amplification.

  18. 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.

  19. 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.

  20. Evolution of sunspot activity and inversion of the Sun's polar magnetic field in the current cycle

    NASA Astrophysics Data System (ADS)

    Mordvinov, A. V.; Grigoryev, V. M.; Erofeev, D. V.

    2015-06-01

    A spatiotemporal analysis of the Sun's magnetic field was carried out to study the polar-field inversion in the current cycle in relation to sunspot activity. The causal relationship between these phenomena was demonstrated in a time-latitude aspect. After decay of long-lived activity complexes their magnetic fields were redistributed into the surrounding photosphere and formed unipolar magnetic regions which were transported to high latitudes. Zones of intense sunspot activity during 2011/2012 produced unipolar magnetic regions of the following polarities, whose poleward drift led to the inversion of the Sun's polar fields at the North and South Poles. At the North Pole the polar field reversal was completed by May 2013. It was demonstrated that mixed magnetic polarities near the North Pole resulted from violations of Joy's law at lower latitudes. Later sunspot activity in the southern hemisphere has led to a delay in magnetic polarity reversal at the South Pole. Thus, the north-south asymmetry of sunspot activity resulted in asynchronous polar field reversal in the current cycle.

  1. Correlations between sunspot numbers, interplanetary parameters and geomagnetic trends over solar cycles 21-23

    NASA Astrophysics Data System (ADS)

    Arora, Kusumita; Chandrasekhar, N. Phani; Nagarajan, Nandini; Singh, Ankit

    2014-07-01

    We have analysed correlations between sunspot numbers, solar wind, ion density, interplanetary magnetic field vis-à-vis magnetic activity. Planetary geomagnetic index (Ap) and local residual measure of magnetic activity (IΔH) from low-latitude Magnetic Observatory, CSIR-NGRI, Hyderabad (IMO-HYB) spanning solar cycles 21-23 are used for this study. Using correlation coefficients between and wavelet decomposition of sunspot numbers, interplanetary parameters and measures of magnetic activity, the complex and time varying nature of these inter-relationships are brought out. The overall influence of sunspot number could be separated and combined episodic effects of other solar parameters could be distinguished. The demonstrated correlation or lack of it, between measures of magnetic activity (Ap and IΔH), and all the parameters of solar activity, presented here corroborate established mechanisms as well as delineated clearly the relative impact of different solar mechanisms over phases of three solar cycles. The possible role of non-sunspot related activity from high latitude regions of the sun is indicated.

  2. On spatial distribution of large sunspot groups during the rise phase and the epoch of maximum in solar cycle 22.

    NASA Astrophysics Data System (ADS)

    Vitinskij, Yu. I.

    1992-07-01

    The butterfly diagram has been plotted for 1986 - 1992 and active longitudes for 1976 - 1982 and 1986 - 1992 are given on the basis of R. S. Gnevysheva's Pulkovo lists of large sunspot groups. It is shown that the latitudinal distribution in number of large sunspot groups is characterized with great concentration towards high-latitude and low-latitude bounderies of sunspot zones and a complicated character of their equatorward latitude migration in the southern solar hemisphere in solar cycle 22. The stability of two active longitudes of large sunspot groups in the northern hemisphere and three in the southern hemisphere has been found. A double peak character of the curve of the large sunspot group number in solar cycle 22, due to the southern hemisphere mainly, has been detected.

  3. Difference between even and odd cycles in the predictability of the amplitude of the around 11-year-period solar activity and prediction of the amplitude of cycle 25

    NASA Astrophysics Data System (ADS)

    Yoshida, A.; Sayre, R. J.

    2012-12-01

    The waxing and waning of the solar activity represented by a period of roughly 11 years is usually quantified by the change in the sunspot number (SSN). It is commonly held that these increases and decreases in the SSN as well as the changes in the general dipole-like magnetic field in the photosphere and corona are produced by a magneto-hydro dynamic process in the sun's underlying convection layer. Assuming this is the case, it follows that SSNs in past cycles should contain a certain kind of information that enables us to estimate the amplitudes of future cycles. We report here a set of new results along this line of research. The chief aim of this paper is to demonstrate a distinct difference in the predictability of solar activity between even and odd cycles. Yoshida and Yamagishi (2010) showed that the SSN at the point three years before a minimum is well correlated with the maximum SSN in the following cycle. Here, we show that the correlation between this locus and the average SSN supplies a higher correlation coefficient. Moreover, we demonstrate that the correlation coefficient for even cycles is far better than that for odd ones (i.e., 0.96 and 0.74, respectively). Though it has been known that the correlation between the SSN at a point three years after a minimum and the maximum SSN is high, we demonstrate here that taking this calculation along with the average SSN (instead of the maximum SSN), the correlation coefficient for even cycles (0.98) reveals itself to be noticeably larger than that for odd cycles (0.93). Furthermore, we have found that the average SSN of even cycles is highly correlated with that of succeeding odd cycles (i.e., the correlation coefficient - minus three outliers - is 0.99). Conversely, no correlation is observed between amplitudes of odd cycles and those of succeeding even cycles. These distinct differences between even-odd pairs and odd-even pairs in their connective features lead us to believe that pairs of even-odd cycles

  4. Lags and Hysteresis Loops of Cosmic Ray Intensity Versus Sunspot Numbers: Quantitative Estimates for Cycles 19 - 23 and a Preliminary Indication for Cycle 24

    NASA Astrophysics Data System (ADS)

    Kane, R. P.

    2014-07-01

    Hysteresis plots between cosmic-ray (CR) intensity (recorded at the Climax station) and sunspot relative number R Z show broad loops in odd cycles (19, 21, and 23) and narrow loops in even cycles (20 and 22). However, in the even cycles, the loops are not narrow throughout the whole cycle; around the sunspot-maximum period, a broad loop is seen. Only in the rising and declining phases, the loops are narrow in even cycles. The CR modulation is known to have a delay with respect to R Z, and the delay was believed to be longer in odd cycles (19, 21, and 23; about 10 months) than the delay in even cycles (20 and 22; about 3 - 5 months). When this was reexamined, it was found that the delays are different during the sunspot-minimum periods (2, 6, and 14 months for odd cycles and 7 and 9 months for even cycles) and sunspot-maximum periods (0, 4, and 7 months for odd cycles and 5 and 8 months for even cycles). Thus, the differences between odd and even cycles are not significant throughout the whole cycle. In the recent even cycle 24, hysteresis plots show a preliminary broadening near the sunspot maximum, which occurred recently (February 2012). The CR level (recorded at Newark station) is still high in 2013, indicating a long lag (exceeding 10 months) with respect to the sunspot maximum.

  5. 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.

  6. 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.

  7. 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. PMID:23261260

  8. 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.

  9. Geomagnetic Activity Indicates Large Amplitude for Sunspot Cycle 24

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.; Wilson, R. M.

    2006-01-01

    The level of geomagnetic activity near the time of solar activity minimum has been shown to be a reliable indicator for the amplitude of the following solar activity maximum. The geomagnetic activity index aa can be split into two components: one associated with solar flares, prominence eruptions, and coronal mass ejections which follows the solar activity cycle and a second component associated with recurrent high speed solar wind streams which is out of phase with the solar activity cycle. This second component often peaks before solar activity minimum and has been one of the most reliable indicators for the amplitude of the following maximum. The size of the recent maximum in this second component indicates that solar activity cycle 24 will be much higher than average - similar in size to cycles 21 and 22.

  10. 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.

  11. Solar Dynamo and the Sunspot Cycle: Current Status and Future Prospects

    NASA Astrophysics Data System (ADS)

    Nandi, Dibyendu

    2016-07-01

    Sunspots are strongly magnetized regions on the Sun's surface that have been observed for over four centuries. The number of sunspots on the solar surface waxes and wanes with an average periodicity of eleven years. The amplitude of this cycle varies and this variation governs the frequency of occurrence of solar storms, solar radiative and particulate output and the heliospheric open flux. This magnetically modulated solar activity variation has consequences for the environment of planets such as the Earth and our space and ground-based technologies. The origin of solar magnetism and its evolution is governed by a magnetohydrodynamic dynamo mechanism that relies on interactions between plasma flows and magnetic fields in the Sun's interior. In this talk I will review our current understanding of the solar dynamo mechanism, highlight outstanding issues and discuss future prospects laying particular emphasis on solar activity predictions.

  12. Flares, Fears, and Forecasts: Public Misconceptions About the Sunspot Cycle

    NASA Astrophysics Data System (ADS)

    Larsen, K.

    2012-06-01

    Among the disaster scenarios perpetrated by 2012 apocalypse aficionados is the destruction of humankind due to solar flares and coronal mass ejections (CMEs). These scenarios reflect common misconceptions regarding the solar cycle. This paper (based on an annual meeting poster) sheds light on those misconceptions and how the AAVSO Solar Section can address them.

  13. The solar dynamo and prediction of sunspot cycles

    NASA Astrophysics Data System (ADS)

    Dikpati, Mausumi

    2012-07-01

    Much progress has been made in understanding the solar dynamo since Parker first developed the concepts of dynamo waves and magnetic buoyancy around 1955, and the German school first formulated the solar dynamo using the mean-field formalism. The essential ingredients of these mean-field dynamos are turbulent magnetic diffusivity, a source of lifting of flux, or 'alpha-effect', and differential rotation. With the advent of helioseismic and other observations at the Sun's photosphere and interior, as well as theoretical understanding of solar interior dynamics, solar dynamo models have evolved both in the realm of mean-field and beyond mean-field models. After briefly discussing the status of these models, I will focus on a class of mean-field model, called flux-transport dynamos, which include meridional circulation as an essential additional ingredient. Flux-transport dynamos have been successful in simulating many global solar cycle features, and have reached the stage that they can be used for making solar cycle predictions. Meridional circulation works in these models like a conveyor-belt, carrying a memory of the magnetic fields from 5 to 20 years back in past. The lower is the magnetic diffusivity, the longer is the model's memory. In the terrestrial system, the great-ocean conveyor-belt in oceanic models and Hadley, polar and Ferrel circulation cells in the troposphere, carry signatures from the past climatological events and influence the determination of future events. Analogously, the memory provided by the Sun's meridional circulation creates the potential for flux-transport dynamos to predict future solar cycle properties. Various groups in the world have built flux-transport dynamo-based predictive tools, which nudge the Sun's surface magnetic data and integrated forward in time to forecast the amplitude of the currently ascending cycle 24. Due to different initial conditions and different choices of unknown model-ingredients, predictions can vary; so

  14. 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.

  15. 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.

    2016-07-01

    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.

  16. A deep-seated mechanism for cycle-dependent sunspot group tilt angles

    NASA Astrophysics Data System (ADS)

    Isik, Emre

    2016-07-01

    The cycle-averaged tilt angle of sunspot groups is an important quantity in determining the magnetic flux diffusing across the equator, which is highly correlated with the strength of the next cycle. This quantity has recently been reported to be anti-correlated with the strength of the solar cycle. I suggest that a deep-seated thermodynamic cycle can be responsible for the observed correlation. Motivated by helioseismic indications, I calculate the effect of cooling of the convective overshoot region on the stability and dynamics of thin, unstable flux tubes. I find that only 5-20 K of cooling in the layer can explain the observed range of tilt angle fluctuations among different cycles. This mechanism can play a role in the nonlinear saturation and amplitude fluctuations of the solar dynamo.

  17. 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.

  18. TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

    SciTech Connect

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

    2011-04-10

    Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

  19. 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.

  20. 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.

  1. A simulation study of two major events in the heliosphere during the present sunspot cycle

    NASA Technical Reports Server (NTRS)

    Akasofu, S. I.; Fillius, W.; Sun, W.; Fry, C.; Dryer, M.

    1985-01-01

    The two major disturbances in the heliosphere during the present sunspot cycle, the event of June to August, 1982, and the event of April to June, 1978, are simulated by the method developed by Hakamada and Akasofu (1982). Specifically, an attempt was made to simulate the effects of six major flares from three active regions in June and July, 1982, and April and May, 1978. A comparison of the results with the solar wind observations at Pioneer 12 (approximately 0.8 au), ISEE-3 (approximately 1 au), Pioneer 11 (approximately 7 to 13 au) and Pioneer 10 (approximately 16 to 28 au) suggests that some major flares occurred behind the disk of the sun during the two periods. The method provides qualitatively some information as to how such a series of intense solar flares can greatly disturb both the inner and outer heliospheres. A long lasting effect on cosmic rays is discussed in conjunction with the disturbed heliosphere.

  2. 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).

  3. Does the Variation of Solar Intra-network Horizontal Field Follow Sunspot Cycle?

    NASA Astrophysics Data System (ADS)

    Jin, C. L.; Wang, J. X.

    2015-07-01

    The ubiquitousness of the solar inter-network horizontal magnetic field has been revealed by space-borne observations with high spatial resolution and polarization sensitivity. However, no consensus has been achieved on the origin of the horizontal field among solar physicists. For a better understanding, in this study, we analyze the cyclic variation of the inter-network horizontal field by using the spectro-polarimeter observations provided by the Solar Optical Telescope on board Hinode, covering the interval from 2008 April to 2015 February. The method of wavelength integration is adopted to achieve a high signal-to-noise ratio. It is found that from 2008 to 2015 the inter-network horizontal field does not vary when solar activity increases, and the average flux density of the inter-network horizontal field is 87 ± 1 G, In addition, the imbalance between horizontal and vertical fields also keeps invariant within the scope of deviation, i.e., 8.7 ± 0.5, from the solar minimum to maximum of solar cycle 24. This result confirms that the inter-network horizontal field is independent of the sunspot cycle. The revelation favors the idea that a local dynamo is creating and maintaining the solar inter-network horizontal field.

  4. 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...

  5. 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.

  6. Estimating sunspot number

    NASA Astrophysics Data System (ADS)

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

    1984-10-01

    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.

  7. Three-dimensional structure of the extended solar magnetic field and the sunspot cycle variation in cosmic ray intensity

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1976-01-01

    A principal cause for the eleven-year sunspot cycle variation in the primary cosmic ray intensity observed at earth may be a variation in the solid angle of the heliosphere occupied by the extended solar polar magnetic field. Galactic cosmic rays have relatively easy access to the inner solar system through the regular extended solar polar fields, and relatively difficult access through the irregular extended solar sector structure fields.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Soil carbon and nitrogen cycling and storage throughout the soil profile in a sweetgum plantation after 11 years of CO2-enrichment

    SciTech Connect

    Iversen, Colleen M; Keller, Dr. Jason K.; Garten Jr, Charles T; Norby, Richard J

    2012-01-01

    Increased partitioning of carbon (C) to fine roots under elevated [CO2], especially deep in the soil profile, could alter soil C and nitrogen (N) cycling in forests. After more than 11 years of free-Air CO2 enrichment in a Liquidambar styraciflua L. (sweetgum) plantation in Oak Ridge, TN, USA, greater inputs of fine roots resulted in the incorporation of new C (i.e., C with a depleted 13C) into root-derived particulate organic matter (POM) pools to 90-cm depth. Even though production in the sweetgum stand was limited by soil N availability, soil C and N content increased over time, and were greater throughout the soil profile under elevated [CO2] at the conclusion of the experiment. However, greater C inputs under elevated [CO2] did not result in increased net N immobilization or C mineralization rates in long-term laboratory incubations, and did not appear to prime the decomposition of older SOM. The 13CO2 of the C mineralized from the incubated soil closely tracked the 13C of the labile POM pool in the elevated [CO2] treatment, especially in shallower soil, and did not indicate the decomposition of older (i.e., pre-experiment) SOM. While potential C mineralization rates were positively and linearly related to total soil organic matter (SOM) C content in the top 30 cm of soil, this relationship did not hold in deeper soil. Taken together with an increased mean residence time of C in deeper soil pools, these findings indicate that C inputs from relatively deep roots under elevated [CO2] may have increased potential for long-term storage. Expanded representation of biogeochemical cycling throughout the soil profile may improve model projections of future forest responses to rising atmospheric [CO2].

  13. 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.

  14. 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

  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. 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

  18. Latitude Dependence of the Variations of Sunspot Group Numbers (SGN) and Coronal Mass Ejections (CMEs) in Cycle 23

    NASA Astrophysics Data System (ADS)

    Kane, R. P.

    2008-06-01

    The 12-month running means of the conventional sunspot number Rz, the sunspot group numbers (SGN) and the frequency of occurrence of Coronal Mass Ejections (CMEs) were examined for cycle 23 (1996 - 2006). For the whole disc, the SGN and Rz plots were almost identical. Hence, SGN could be used as a proxy for Rz, for which latitude data are not available. SGN values were used for 5° latitude belts 0° - 5°, 5° - 10°, 10° - 15°, 15° - 20°, 20° - 25°, 25° - 30° and > 30°, separately in each hemisphere north and south. Roughly, from latitudes 25° - 30° N to 20° - 25° N, the peaks seem to have occurred later for lower latitudes, from latitudes 20° - 25° N to 15° - 20° N, the peaks are stagnant or occur slightly earlier, and then from latitudes 15° - 20° N to 0° - 5° N, the peaks seem to have occurred again later for lower latitudes. Thus, some latitudinal migration is suggested, clearly in the northern hemisphere, not very clearly in the southern hemisphere, first to the equator in 1998, stagnant or slightly poleward in 1999, and then to the equator again from 2000 onwards, the latter reminiscent of the Maunder butterfly diagrams. Similar plots for CME occurrence frequency also showed multiple peaks (two or three) in almost all latitude belts, but the peaks were almost simultaneous at all latitudes, indicating no latitudinal migration. For similar latitude belts, SGN and CME plots were dissimilar in almost all latitude belts except 10° - 20° S. The CME plots had in general more peaks than the SGN plots, and the peaks of SGN often did not match with those of CME. In the CME data, it was noticed that whereas the values declined from 2002 to 2003, there was no further decline during 2003 - 2006 as one would have expected to occur during the declining phase of sunspots, where 2007 is almost a year of sunspot minimum. An inquiry at GSFC-NASA revealed that the person who creates the preliminary list was changed in 2004 and the new person picks out

  19. Characterizing and modeling magnetic flux transport in the sun's photosphere and determining its impact on the sunspot cycle

    NASA Astrophysics Data System (ADS)

    Upton, Lisa A.

    The characterization and modeling of magnetic flux transport within the surface layers of the Sun are vital to explaining the sunspot cycle. The Sun's polar fields at solar cycle minimum are the seeds of the next solar cycle: weak polar fields produce weak cycles. Magnetic flux transport is key to the buildup of the polar fields and the subsequent magnetic reversals that are essential to modulating the sunspot cycle. The primary goals of this dissertation are threefold: 1. Make precise measurements of the Sun's axisymmetric flows (i.e., differential rotation and meridional flow). 2. Create a realistic surface flux transport model that reproduces the magnetic field evolution at the surface by incorporating the observed flows. 3. Investigate the role of flux transport in modulating the polar fields, and thereby the solar activity cycle. This work has been done in collaboration with Dr. David H. Hathaway of NASA Marshall Space Flight Center. In Chapter 1, I provide an introduction to the Sun as a star. I begin with a discussion on stellar structure and evolution. I then discuss the techniques and instruments that have been used to study the Sun. I conclude Chapter 1 with a section on magnetic activity cycles on the Sun and in other stars. Magnetic flux on the Sun is transported by supergranular flows and the axisymmetric flows of differential rotation (DR) and meridional flow (MF). In Chapter 2, I introduce these flows. I then show a derivation of the Surface Flux Transport equation starting from Maxwell's equations and Ohm's Law. I conclude this chapter with an introduction to prior Surface Flux Transport models. In Chapter 3, I discuss a cross-correlation technique that we have used on magnetograms (maps of the magnetic field strengths over the surface of the Sun) to characterize the DR and MF and their variations from 1996 to present. Results show that while variability in DR is negligible, the MF varies in two fundamental ways: over the course of a solar cycle and

  20. The latitudinal distributions of sunspot areas and magnetic fields and their correlation with the background solar magnetic field in the cycle 23

    NASA Astrophysics Data System (ADS)

    Zharkov, S. I.; Gavryuseva, E. V.; Zharkova, V. V.

    The quasi 3D latitudinal distributions (butterfly diagrams) of sunspot areas and magnetic fields obtained within the whole μ-hemispheres in longitudes from the Solar Feature Catalogues for 9 years (1996-2005) of the cycle 23 are correlated with those of the low-resolution solar magnetic fields (SMF) obtained from Wilcox Solar Observatory. During the whole period of observations the sunspot areas reveal a strong positive correlation with SMF appearing at zero timelag and repeating at the 2-2.5 year time lags after or before the cycle start. The high positive correlation coefficients are also distributed into the four zones reflecting the sunspot migration directions: the two pre-polar zones above ±45° with the positive correlation increasing towards the poles (the sunspot migration towards the poles) and the two pre-equatorial zones from -40° to +40° (the 'royal zone') with the positive correlation increasing toward the equator as seen in the butterfly diagrams. This correlation suggests a modulating effect of the symmetric component of SMF on the magnitude of magnetic field in flux tubes emerging as sunspots. The symmetric SMF components have the same signs in each hemisphere and they are changed to opposite over the period 2-2.5 year. Then, if the signs of the symmetric SMF coincides with the leading polarity signs in a one hemisphere and opposite in the other one, the flux tube emergence (and sunspot appearance) is supported by SMF in the first one and suppressed in the other. While in 2.5 years when the SMF sign is changed to the opposite, the flux emergence is supported in the other hemisphere but suppressed in the first one.

  1. Counting Sunspots from Space (Invited)

    NASA Astrophysics Data System (ADS)

    Watson, F. T.

    2013-12-01

    Space based measurements of sunspots are still relatively new when compared with the long visual record that is available from ground based observatories, but they can provide many advantages that ground based measurements cannot. Sunspots are automatically detected from SOHO/MDI and SDO/HMI continuum images using the Sunspot Tracking And Recognition Algorithm (STARA). This creates a self consistent sunspot catalogue which enables certain human factors such as changing observers or the degradation of an observers eyesight as they age to be eliminated. The catalogue is analysed to determine how sunspot populations evolve as the solar activity cycle changes, which is of importance to how solar activity is generated. It is also linked to the Sun - Earth connection as learning more about solar activity allows the solar impact on Earth to be better understood. The sunspot catalogue is freely available for use by the scientific community.

  2. 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

  3. Erratum: Evidence That a Deep Meridional Flow Sets the Sunspot Cycle Period

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    An error was made in entering the data. This changes the results concerning the length of the time lag between the variations in the meridional flow speed and those in the cycle amplitude. The final paragraph on page 667 should read: Finally, we study the relationship between the drift velocities and the amplitudes of the hemisphere/cycles. We compare the drift velocity at the maximum of the cycle to the amplitude of that cycle for that hemisphere. There is a positive (0.5) and significant (95%) correlation between the two. However, an even stronger relationship is found between the drift velocity and the amplitude of the N + 2 cycle. The correlation is stronger (0.7) and more significant (99%), as shown. This relationship is suggestive of a "memory" in the solar cycle, again a property of dynamo models that use meridional circulation. Indeed, the two-cycle lag is precisely the relationship found by Charbonneau & Dikpati. This behavior is, however, more difficult to interpret, and we elaborate on this in the next section. In either case, these correlations only explain part of the variance in cycle amplitude (25% for the current cycle and 50% for the N + 2 cycle). Obviously, other mechanisms, such as variations in the gradient in the rotation rate, also contribute to the cycle amplitude variations. Our investigation of possible connections between drift rates and the amplitudes of the N + 1 and N + 3 cycles gives no significant correlations at these alternative time lags.

  4. 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.

  5. 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.

  6. On the nature of IMF polarity dependent asymmetries in solar wind plasma properties during the minimum of sunspot cycles 23 and 24

    NASA Astrophysics Data System (ADS)

    Pereira, B. Felix; Philip, Bijoy John; Girish, T. E.

    2016-03-01

    The monthly solar wind speed and density observed near 1 AU in IMF sectors of opposite magnetic polarity are studied during the minimum of sunspot cycles 23 and 24. During sunspot minima, the IMF is pointing away from the sun (Away sector) in the north of the Heliospheric Current Sheet (HCS) and pointing towards the sun (Toward sector) in the south of HCS during odd sunspot cycles and the same process is reversed during the even cycles. During this period, the solar wind plasma parameters (number density and speed) show a systematic month to month variation with solar wind number density decreases and velocity increases from equator to poles (heliomagnetic latitudinal organization) only in 'Away' IMF sectors compared to 'Toward' IMF sectors. This feature is particularly more evident for low speed solar wind and happens in a helio-hemisphere with a larger polar coronal hole. The association of the above phenomena with north-south asymmetry in coronal and solar wind flow characteristics will be discussed.

  7. Multifractal Analysis of Sunspot Number Time Series

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    Multifractal analysis based approaches have been recently developed as an alternative framework to study the complex dynamical fluctuations in sunspot numbers data including solar cycles 20 to 23 and ascending phase of current solar cycle 24.To reveal the multifractal nature, the time series data of monthly sunspot number are analyzed by singularity spectrum and multi resolution wavelet analysis. Generally, the multifractility in sunspot number generate turbulence with the typical characteristics of the anomalous process governing the magnetosphere and interior of Sun. our analysis shows that singularities spectrum of sunspot data shows well Gaussian shape spectrum, which clearly establishes the fact that monthly sunspot number has multifractal character. The multifractal analysis is able to provide a local and adaptive description of the cyclic components of sunspot number time series, which are non-stationary and result of nonlinear processes. Keywords: Sunspot Numbers, Magnetic field, Multifractal analysis and wavelet Transform Techniques.

  8. 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.

  9. 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.

  10. 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.

  11. The sunspot cycle no. 24 in relation to long term solar activity variation

    PubMed Central

    Komitov, Boris; Kaftan, Vladimir

    2013-01-01

    The solar minimum between solar cycles 23 and 24 during the period 2007–2009 has been the longest and deepest one at least since for the last 100 years. We suggest that the Sun is going to his next supercenturial minimum. The main aim of this paper is to tell about arguments concerning this statement. They are based on series of studies, which have been provided during the period since 1997 up to 2010. The progress of solar cycle 24 since its minimum at the end of 2008 up to the end of October 2011 in the light of long term solar activity dynamics is analyzed. PMID:25685429

  12. The sunspot cycle no. 24 in relation to long term solar activity variation.

    PubMed

    Komitov, Boris; Kaftan, Vladimir

    2013-05-01

    The solar minimum between solar cycles 23 and 24 during the period 2007-2009 has been the longest and deepest one at least since for the last 100 years. We suggest that the Sun is going to his next supercenturial minimum. The main aim of this paper is to tell about arguments concerning this statement. They are based on series of studies, which have been provided during the period since 1997 up to 2010. The progress of solar cycle 24 since its minimum at the end of 2008 up to the end of October 2011 in the light of long term solar activity dynamics is analyzed. PMID:25685429

  13. 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

  14. 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.

  15. Sunspot random walk and 22-year variation

    NASA Astrophysics Data System (ADS)

    Love, Jeffrey J.; Rigler, E. Joshua

    2012-05-01

    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 log-normal 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.

  16. 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.

  17. A simulation study of two major events in the heliosphere during the present sunspot cycle

    NASA Technical Reports Server (NTRS)

    Akasofu, S. L.; Sun, W.; Fry, C.; Fillius, W.; Dryer, M.

    1985-01-01

    Disturbances in the heliosphere which occurred during two of the most active periods of the sun during the present solar cycle, in June and July 1982 and April and May 1978, are qualitatively simulated using the method of Hakamada and Akasofu (1982). A first-order spatial and temporal construction of flare-generated shocks and their multiple interactions with each other and with cororating interaction regions is obtained. A comparison of the results with solar wind observations from Pioneer 10, 11, and 12 suggests that some major flares occurred behind the solar disk during the two periods. The present method provides some qualitative information on how such a series of intense solar flares can greatly disturb both the inner and outer heliospheres. A long-lasting effect on cosmic rays which occurs in conjunction with such disturbances is discussed.

  18. Simulations of the sun's polar magnetic fields during sunspot cycle 21

    NASA Technical Reports Server (NTRS)

    Devore, C. Richard; Sheeley, Neil R., Jr.

    1987-01-01

    Regarding new bipolar magnetic regions as sources of flux, the evolution of the radial component of the solar photospheric magnetic field is simulated during 1976-1984, and the corresponding evolution of the line-of-sight polar fields as seen from earth is derived. The observed timing and strength of the polar-field reversal during cycle 21 can be accounted for by supergranular diffusion alone, for a diffusion coefficient of 800 sq km/sec. For an assumed 300 sq km/sec rate of diffusion, on the other hand, a poleward meridional flow with a moderately broad profile and a peak speed of 10 m/s reached at about 5 deg latitude is required to obtain agreement between the simulated and observed fields. Such a flow accelerates the transport of following-polarity flux to the polar caps, but also inhibits the diffusion of leading-polarity flux across the equator. For flows faster than about 10 m/s, the latter effect dominates, and the simulated polar fields reverse increasingly later and more weakly than the observed fields.

  19. 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.

  20. 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.

  1. On the Rotation of Sunspots and Their Magnetic Polarity

    NASA Astrophysics Data System (ADS)

    Zheng, Jianchuan; Yang, Zhiliang; Guo, Kaiming; Wang, Haimin; Wang, Shuo

    2016-07-01

    The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observataory. We choose the α sunspot groups and the relatively large and stable sunspots of complex active regions in our sample. In the year of 2003, the α sunspot groups and the preceding sunspots tend to rotate counterclockwise and have positive magnetic polarity in the northern hemisphere. In the southern hemisphere, the magnetic polarity and rotational tendency of the α sunspot groups and the preceding sunspots are opposite to the northern hemisphere. The average rotational speed of these sunspots in 2003 is about 0.°65 hr‑1. From 2014 January to 2015 February, the α sunspot groups and the preceding sunspots tend to rotate clockwise and have negative magnetic polarity in the northern hemisphere. The patterns of rotation and magnetic polarity of the southern hemisphere are also opposite to those of the northern hemisphere. The average rotational speed of these sunspots in 2014/2015 is about 1.°49 hr‑1. The rotation of the relatively large and stable preceding sunspots and that of the α sunspot groups located in the same hemisphere have opposite rotational direction in 2003 and 2014/2015.

  2. 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.

  3. 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.

  4. 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

  5. What the Sunspot Record Tells Us About Space Climate

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Wilson, Robert M.

    2004-01-01

    The records concerning the number, sizes, and positions of sunspots provide a direct means of characterizing solar activity over nearly 400 years. Sunspot numbers are strongly correlated with modem measures of solar activity including: 10.7-cm radio flux, total irradiance, x-ray flares, sunspot area, the baseline level of geomagnetic activity, and the flux of galactic cosmic rays. The Group Sunspot Number provides information on 27 sunspot cycles, far more than any of the modem measures of solar activity, and enough to provide important details about long-term variations in solar activity or Space Climate. The sunspot record shows: 1) sunspot cycles have periods of 131 plus or minus 14 months with a normal distribution; 2) sunspot cycles are asymmetric with a fast rise and slow decline; 3) the rise time from minimum to maximum decreases with cycle amplitude; 4) large amplitude cycles are preceded by short period cycles; 5 ) large amplitude cycles are preceded by high minima; 6) although the two hemispheres remain linked in phase, there are significant asymmetries in the activity in each hemisphere; 7) the rate at which the active latitudes drift toward the equator is anti-correlated with the cycle period, 8) the rate at which the active latitudes drift toward the equator is positively correlated with the amplitude of the cycle after the next; 9) there has been a significant secular increase in the amplitudes of the sunspot cycles since the end of the Maunder Minimum (1715); and 10) there is weak evidence for a quasi-periodic variation in the sunspot cycle amplitudes with a period of about 90 years. These characteristics indicate that the next solar cycle should have a maximum smoothed sunspot number of about 1.45 plus or minus 30 in 2010 while the following cycle should have a maximum of about 70 plus or minus 30 in 2023.

  6. 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)

  7. 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.

  8. 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.

  9. Interactions between externally forced climate signals from sunspot peaks and the internally generated Pacific Decadal and North Atlantic Oscillations

    NASA Astrophysics Data System (ADS)

    Loon, Harry; Meehl, Gerald A.

    2014-01-01

    When the Pacific Decadal Oscillation is in phase with the 11 year sunspot cycle, there are positive sea level pressure (SLP) anomalies in the Gulf of Alaska, nearly no anomalous zonal SLP gradient across the equatorial Pacific, and a mix of small positive and negative sea surface temperature (SST) anomalies there. When the two indices are out of phase, positive SLP anomalies extend farther south in the Gulf of Alaska and west into eastern Russia, with a strengthened anomalous zonal equatorial Pacific SLP gradient and larger magnitude and more extensive negative SST anomalies along the equatorial Pacific. In the North Atlantic, when the North Atlantic Oscillation (NAO) is in phase with the sunspot peaks, there is an intensified positive NAO SLP pattern. When the NAO is out of phase with the peaks, there is the opposite pattern (negative NAO). The relationships are physically consistent with previously identified processes and mechanisms and point the way to further research.

  10. 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%.

  11. 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%.

  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. 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)

  14. A Curious History of Sunspot Penumbrae

    NASA Astrophysics Data System (ADS)

    Hathaway, D. H.

    2013-09-01

    Daily records of sunspot group areas compiled by the Royal Observatory, Greenwich, from May of 1874 through 1976 indicate a curious history for the penumbral areas of the smaller sunspot groups. On average, the ratio of penumbral area to umbral area in a sunspot group increases from 5 to 6 as the total sunspot group area increases from 100 to 2000 μHem (a μHem is 10-6 the area of a solar hemisphere). This relationship does not vary substantially with sunspot group latitude or with the phase of the sunspot cycle. However, for the sunspot groups with total areas < 100 μHem, this ratio changes dramatically and systematically through this historical record. The ratio for these smallest sunspots is near 5.5 from 1874 to 1900. After a rapid rise to more than 7 in 1905, it drops smoothly to less than 3 by 1930 and then rises smoothly back to more than 7 in 1961. It then returns to near 5.5 from 1965 to 1976. The smooth variation from 1905 to 1961 shows no indication of any step-like changes that might be attributed to changes in equipment or personnel. The overall level of solar activity was increasing monotonically during this time period when the penumbra-to-umbra area ratio dropped to less than half its peak value and then returned. If this history can be confirmed by other observations ( e.g. Mt. Wilson or Kodaikanal), it may impact our understanding of penumbra formation, our dynamo models, and our estimates of historical changes in the solar irradiance.

  15. Persistent active longitudes in sunspot activity

    NASA Astrophysics Data System (ADS)

    Berdyugina, S.; Usoskin, I.

    It has been recently shown that spot activity of cool stars including solar analogues, is grouped in two clearly distinguished active longitudes which are persistent within at least one starspot cycle. Solar data including positional information of individual sunspots / groups extends back for about 130 years covering 12 solar cycles. Here we present the results of our research of longitudinal distribution of sunspot activity using an analysis similar to that applied to the stars. First, we synthesized, from the actual sunspot data, the sun's light curve as if it was defined only by spots. Then solar images were calculated from this light curve, giving a natural smoothing of the spot pattern. For each Carrington rotation, longitudinal position of these smoothed spot regions was calculated. The analysis reveals the following main features: - Sunspot activity is grouped in two active longitudes (with the differential rotation taken into account) 180o apart from each other which are persistent through the entire studied period of 12 cycles, similarly to stars. - The longitude migration is determined by changing the mean latitude of sunspot activity (the Maunder butterfly) and differential rotation. - The two longitudes periodically alternate the dominant activity with about 3.7 year period implying for the existence of the Sflip-flopT phenomenon known in - starspot activity.

  16. 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.

  17. 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

  18. What causes geomagnetic activity during sunspot minimum?

    NASA Astrophysics Data System (ADS)

    Kirov, B.; Asenovski, S.; Georgieva, K.; Obridko, V. N.

    2015-12-01

    It is well known that the main drivers of geomagnetic disturbances are coronal mass ejections whose number and intensity are maximum in sunspot maximum, and high speed solar wind streams from low latitude solar coronal holes which maximize during sunspot declining phase. But even during sunspot minimum periods when there are no coronal mass ejections and no low latitude solar coronal holes, there is some "floor" below which geomagnetic activity never falls. Moreover, this floor changes from cycle to cycle. Here we analyze the factors determining geomagnetic activity during sunspot minimum. It is generally accepted that the main factor is the thickness of the heliospheric current sheet on which the portion of time depends which the Earth spends in the slow and dense heliospheric current sheet compared to the portion of time it spends in the fast solar wind from superradially expanding polar coronal holes. We find, however, that though the time with fast solar wind has been increasing in the last four sunspot minima, the geomagnetic activity in minima has been decreasing. The reason is that the parameters of the fast solar wind from solar coronal holes change from minimum to minimum, and the most important parameter for the fast solar wind's geoeffectivity—its dynamic pressure—has been decreasing since cycle 21. Additionally, we find that the parameters of the slow solar wind from the heliospheric current sheet which is an important driver of geomagnetic activity in sunspot minimum also change from cycle to cycle, and its magnetic field, velocity and dynamic pressure have been decreasing during the last four minima.

  19. 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].

  20. Modeling the Relationship Between Neutron Counting Rates and Sunspot Numbers Using the Hysteresis Effect

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    Several studies show that temporal variations in the Galactic cosmic ray (GCR) intensity display a distinct 11-year periodicity due to solar modulation of the galactic cosmic rays in the heliosphere. The 11-year periodicity of GCRs is inversely proportional to, but out of phase with, the 11-year solar cycle, implying that there is a time lag between actual solar cycle and the GCR intensity, which is known as the hysteresis effect. In this study, we use the hysteresis effect to model the relationship between neutron counting rates (NCRs), an indicator of the GCR intensity, and sunspot numbers (SSNs) over the period that covers the last four solar cycles (20, 21, 22, and 23). Both linear and ellipse models were applied to SSNs during odd and even cycles in order to calculate temporal variations of NCRs. We find that ellipse modeling provides higher correlation coefficients for odd cycles compared to linear models, e.g. 0.97, 0.97, 0.92, and 0.97 compared to 0.69, 0.72, 0.53, and 0.68 for data from McMurdo, Swarthmore, South Pole, and Thule neutron monitors, respectively, during solar cycle 21 with overall improvement of 31 % for odd cycles. When combined to a continuous model, the better correlation observed for the odd cycles increases the overall correlation between observed and modeled NCRs. The new empirical model therefore provides a better representation of the relationship between NCRs and SSNs. A major goal of the ongoing research is to use the new non-linear empirical model to reconstruct SSNs on annual time scales prior to 1610, where we do not have observational records of SSNs, based on changes in NCRs reconstructed from 10Be in ice cores.

  1. A Systematic Look At Sunspots From Space: 1996 - 2013

    NASA Astrophysics Data System (ADS)

    Watson, Fraser; Penn, M. J.; Livingston, W.

    2013-07-01

    Space based measurements of sunspots are still relatively new when compared with the long visual record that is available from ground based observatories, but they can provide many advantages that ground based measurements cannot. Sunspots are automatically detected from SOHO/MDI and SDO/HMI continuum images using the Sunspot Tracking And Recognition Algorithm (STARA). A self consistent sunspot catalogue is created using the same criteria for detecting sunspots throughout time, eliminating effects seen by ground observatories such as changing observers or the effect of an observers eyesight as they age. This catalogue is then analysed to determine how sunspots evolve and what their population is in a number of physical parameters, which is of great importance for simulations of magnetic flux emergence and the solar dynamo. In particular, the change in sunspot parameters between solar cycles 23 and 24 is of great interest as the cycles appear vastly different in activity, and sunspots are a primary indicator of the activity of the Sun. The catalogue is also freely available for use by the community.

  2. 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.

  3. 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.

  4. Trends in solar UV and EUV irradiance: An update to the MgII Index and a comparison of proxies and data to evaluate trends of the last 11-year solar cycle

    NASA Astrophysics Data System (ADS)

    Viereck, R. A.; Snow, M.; Deland, M. T.; Weber, M.; Puga, L.; Bouwer, D.

    2010-12-01

    Long records of solar spectral irradiance are quite rare and differentiating between solar variability and instrumental changes can be a challenge. Proxies for solar irradiance have provided independent measures of solar variability and can be used to extend the data record beyond the observation period and to help differentiate solar variability from instrument drifts. Recently however there are indications that the relationships, that have remained relatively constant over the last several solar cycles, have changed significantly during this recent cycle. There are increasing divergences between the proxies and the observed irradiances. This divergence may indicate a fundamental change in the sun itself. We will present an update to the MgII composite index which is used a proxy for solar EUV, UV, and total irradiances. We will examine this recent solar minimum period and compare the MgII and other proxies to each other and to the EUV, UV, and TSI in an effort to better understand the past, present, and future solar spectral irradiance records.

  5. 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.

  6. On the insignificance of Herschel's sunspot correlation

    NASA Astrophysics Data System (ADS)

    Love, Jeffrey J.

    2013-08-01

    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. The Impact Of Torsional Oscillations On The Solar Cycle: The Waldmeier-effect As An Outcome

    NASA Astrophysics Data System (ADS)

    Mahajan, Sushant S.; Nandy, Dibyendu; Dwivedi, Bhola N.; Antia, H. M.

    2016-05-01

    Temporal variations in the Sun’s internal velocity field with a periodicity of about 11 years have been observed in the last three decades. The period of these torsional oscillations and their latitudinal propagation roughly coincide with the period and equatorward propagation of sunspots which originate from a magnetohydrodynamic dynamo mechanism operating in the Sun’s interior. While the solar differential rotation plays an important role in this dynamo mechanism by inducting the toroidal component of magnetic field, the impact of torsional oscillations on the dynamo mechanism – and hence the solar cycle – is not well understood. Here, we include the observed torsional oscillations into a flux transport dynamo model of the solar cycle to inves- tigate their effect. Although the overall amplitude of the solar cycle does not change significantly on inclusion of torsional oscillations we find that all the characteristics of the Waldmeier effect inthe sunspot cycle are qualitatively reproduced by varying only the amplitude of torsional oscillations. The Waldmeier effect, first noted in 1935, includes the important characteristic that the amplitude of sunspot cycles is anti-correlated to their rise time; cycles with high initial rise rate tend to be stronger. This has implications for solar cycle predictions. Our result suggests that the Waldmeier effect is a plausible outcome of cycle-to-cycle modulation of torsional oscillations and provides a physical basis for sunspot cycle forecasts based on torsional oscillation observations.

  8. 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

  9. 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.

  10. 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.

  11. MHD Wave in Sunspots

    NASA Astrophysics Data System (ADS)

    Sych, Robert

    2016-02-01

    The study of magnetohydrodynamic (MHD) waves and oscillations in the solar atmosphere is one of the fastest developing fields in solar physics, and lies in the mainstream of using solar instrumentation data. This chapter first addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, and height localization with the mechanism of cutoff frequency that forms the observed emission variability. Then, it presents a review dynamic of sunspot wave processes, provides the information about the structure of wave fronts and their time variations, and investigates the oscillation frequency transformation depending on the wave energy. The chapter also addresses the initializing solar flares caused by trigger agents like magnetoacoustic waves, accelerated particle beams, and shocks. Special attention is paid to the relation between the flare reconnection periodic initialization and the dynamics of sunspot slow magnetoacoustic waves.

  12. 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

  13. Unusual Migration of Prominence Activities in the Southern Hemisphere during Cycles 23-24

    NASA Astrophysics Data System (ADS)

    Shimojo, Masumi

    2013-12-01

    The solar activity in Cycles 23-24 shows differences from the previous cycles that were observed with modern instruments, e.g., long cycle duration and a small number of sunspots. To appreciate the anomalies further, we investigated the prominence eruptions and disappearances observed with the Nobeyama Radioheliograph for over 20 years. Consequently, we found that the occurrence of prominence activities in the northern hemisphere is normal because the period of the number variation is 11 years, and the migration of the producing region of the prominence activities traces the migration of 11 years ago. On the other hand, the migration in the southern hemisphere significantly differs from that in the northern hemisphere and the previous cycles. The prominence activities occurred over -50° latitude in spite of the late decay phase of Cycle 23, and the number of prominence activities in the higher latitude region (over -65°) is very small, even near the solar maximum of Cycle 24. The results suggest that the anomalies of the global magnetic field distribution started at the solar maximum of Cycle 23. A comparison of the butterfly diagram of the prominence activities with the magnetic butterfly diagram indicates that the timing of "the rush to the pole" and the polar magnetic field closely relates to unusual migration. Considering that the rush to the pole is made of the sunspots, the hemispheric asymmetry of the sunspots and the strength of the polar magnetic fields are essential for understanding the anomalies of the prominence activities.

  14. 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.

  15. On the relationship between sunspots number and the flare index

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1994-01-01

    During the years 1976-1991, sunspot number and the Kleczek flare index have displayed a strong linear correlation (r = 0.94), one that can be described by the equation y = -0.15 + 0.10 x, where x denotes annual sunspot number. While true, the temporal behaviors of the two parameters have differed, with sunspot number peaking first in 1979 and the flare index peaking much later in 1982 during cycle 21 and with more contemporaneous behavior in cycle 22 (both peaking in 1989, with a secondary peak in 1991). The difference appears to be directly attributable to the way in which the Kleczek flare index has been defined; namely, the annual flare index is the sum of the product of each flare's intensity (importance) times its duration (in minutes) divided by the total number of flares during the year. Because the number of 'major' flares (those of importance greater than or equal to 2) and flares of very long duration (duration greater than or equal to 100 min) both peaked after sunspot maximum (1982/81, respectively) in cycle 21, one should have expected the flare index to also peak (which it did). Likewise, because the number of major flares and flares of very long duration peaked simultaneously with sunspot number (1989) in cycle 22, one should have expected the flare index to also peak (which it did).

  16. Planetary tides during the Maunder Sunspot Minimum

    NASA Technical Reports Server (NTRS)

    Smythe, C. M.; Eddy, J. A.

    1977-01-01

    In order to test the tidal theory of sunspots, sun-centered planetary conjunctions and tidal potentials are reconstructed for the period of the Maunder Minimum (1645 to 1715). These are found to be effectively indistinguishable from patterns of conjunctions and power spectra of tidal potential in the modern era of a well-established 11-yr sunspot cycle. The pattern of planetary tidal forces during the Maunder Minimum is then reconstructed to investigate the possibility that multiple-planet forces were somehow fortuituously cancelled at that time; i.e., the positions of the slower moving planets in the late 17th and early 18th centuries were such that conjunctions and tidal potentials were reduced in number and force. Calculations of daily positions for Mercury, Venus, earth, and Jupiter as well as daily values of the tidal potential for the period from 1450 to 2000 indicate no striking dissimilarities between the time of the Maunder Minimum and any other period considered.

  17. Coupled G-Mode Intersections and Solar-Cycle Variability

    NASA Astrophysics Data System (ADS)

    Juckett, David A.

    2010-03-01

    Wolff ( Astrophys. J. 193, 721, 1974) introduced the concept of g-mode coupling within the solar interior. Subsequently, Wolff developed a more quantitative model invoking a reciprocal interaction between coupled g modes and burning in the solar core. Coupling is proposed to occur for constant values of the spherical harmonic degree [ ℓ] creating rigidly rotating structures denoted as sets( ℓ). Power would be concentrated near the core and the top of radiative zone [RZ] in narrow intervals of longitude on opposite sides of the Sun. Sets( ℓ) would migrate retrograde in the RZ as function of ℓ and their intersections would deposit extra energy at the top of the RZ. It is proposed that this enhances sunspot eruptions at particular longitudes and at regular time intervals. Juckett and Wolff ( Solar Phys. 252, 247, 2008) detected this enhancement by viewing selected spherical harmonics of sunspot patterns within stackplots twisted into the relative rotational frames of various sets( ℓ). In subsequent work, the timings of the set( ℓ) intersections were compared to the sub-decadal variability of the sunspot cycle. Seventeen sub-decadal intersection frequencies (0.63 - 7.0 year) were synchronous with 17 frequencies in the sunspot time-series with a mean correlation of 0.96. Six additional non-11-year frequencies (periods of 8.0 to 28.7 year) are now shown to be nearly synchronous between sunspot variability and the model. Two additional intersections have the same frequency as the solar cycle itself and peak during the rising phase of the solar cycle. This may be partly responsible for cycle asymmetry. These results are evidence that some of the solar-cycle variability may be attributable to deterministic components that are intermixed with a broad-spectrum stochastic and long-term chaotic background.

  18. 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.

  19. Role of Coronal Mass Ejections in the Heliospheric Hale Cycle

    NASA Technical Reports Server (NTRS)

    Owens, M. J.; Schwardron, N. A.; Crooker, N. U.; Hughes, W. J.; Spence, H. E.

    2007-01-01

    The 11-year solar cycle variation in the heliospheric magnetic field strength can be explained by the temporary buildup of closed flux released by coronal mass ejections (CMEs). If this explanation is correct, and the total open magnetic flux is conserved, then the interplanetary-CME closed flux must eventually open via reconnection with open flux close to the Sun. In this case each CME will move the reconnected open flux by at least the CME footpoint separation distance. Since the polarity of CME footpoints tends to follow a pattern similar to the Hale cycle of sunspot polarity, repeated CME eruption and subsequent reconnection will naturally result in latitudinal transport of open solar flux. We demonstrate how this process can reverse the coronal and heliospheric fields, and we calculate that the amount of flux involved is sufficient to accomplish the reversal within the 11 years of the solar cycle.

  20. Analysis Of Sunspot Number Counts, Sunspot Area, And Sunspot Irradiance Deficit: 2002-2011

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Henry, T.

    2011-05-01

    Sunspot numbers have been traditionally associated with strength of solar activity, and feed into a variety of space weather forecast models. We present a detailed analysis of (i) sunspot number counts, (ii) sunspot area, (iii) their component umbral and penumbral intensities, and (iv) sunspot irradiance deficit as measured from 5-minute cadence true continuum images observed with the USAF/AFRL's Improved Solar Observing Optical Network (ISOON) prototype telescope. The data were acquired from December 2002 - present. These measures are obtained, semi-automatically. We relate these observed measures to the daily NOAA/SWPC Sunspot Numbers, and International Sunspot Numbers, and trace the intra-day fluctuations in sunspot numbers to its component constituents. With higher data cadence of modern instruments, we relate the advantages and disadvantages of automating the process. We trace inherent fluctuations in sunspot numbers to the underlying solar activity, and relate them to the solar eruptive process. This work was supported by the Air Force Office of Scientific Research (AFOSR)

  1. Nomogram for sunspot numbers.

    NASA Astrophysics Data System (ADS)

    Upreti, U. C.

    1997-12-01

    Nomogram construction using the parabolic relationship f0F2 = a0+a1R12+a2R122 between monthly median f0F2 and running average sunspot number (RASSN) R12 values has been described; here a0, a1 and a2 are the best fit coefficients. The nomogram can give the required local effective sunspot number (LESSN) values corresponding to any observed value of f0F2. Transforming the f0F2-RASSN relation to the form R122+pR12+q = 0 [where p = a1/a2 and q = (a0-f0F2)/a2], a practical method for the preparation of a single nomogram for f0F2-RASSN has been described and the problem of very high and very low values of the variables has also been dealt with successfully. A single nomogram for a large range of variables, namely, f0F2, a0, a1, and a2 has been obtained so that one can easily find LESSN values at any location, season, and time. The nomogram tends to minimize the errors in LESSN calculations at all levels of solar activity.

  2. Rotational periodicities in sunspot relative numbers

    NASA Astrophysics Data System (ADS)

    Balthasar, H.

    2007-08-01

    Context: The search for active longitudes on the Sun has a long history, and many controversial results have been published. Recently the question became more important when active longitudes were found on other stars. Aims: The aim of this paper is to investigate an integral measure of solar activity available for a long time interval and which allows enough frequency resolution for the investigation of active longitudes. Such a measure is given by the daily sunspot relative numbers. Methods: A search for periodicities is performed with a classical Fast Fourier Transform (FFT), with a wavelet analysis and with the tool of superimposed epochs. Results: The FFT yields a hump of power peaks near the synodic rotation period of 27 days, but only a very weak and insignificant enhancement around 13.5 days, indicating that the mean rotational variation of the sunspot numbers typically has one maximum and one minimum (overlaid by minor fluctuations). The wavelet analysis shows that spectral power for single periods varies for certain time intervals. A systematic drift during the solar activity cycle is not detected. Similar results are obtained from the superimposed epochs. Periodic “flip-flops” with time scales of a few years as for some stars are not found for the Sun in this investigation. Conclusions: Sunspots are not distributed equally over the longitudes; there is a more active and a less active hemisphere. The rotation period derived from the pattern varies over long time scales. The results found in this work are not in favor of an explanation of the variations due to a differential rotation law. The rotation of the sunspot distribution pattern might reflect the internal rotation of the Sun, but it better fits the range of highest rotation rates in the upper convection zone than the rotation near the tachocline. Figure [see full text] is only available in electronic form at http://www.aanda.org

  3. 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.

    2016-02-01

    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.

  4. 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.

  5. 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.

  6. MODELING THE SUNSPOT NUMBER DISTRIBUTION WITH A FOKKER-PLANCK EQUATION

    SciTech Connect

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

    2011-05-01

    Sunspot numbers exhibit large short-timescale (daily-monthly) variation in addition to longer-timescale variation due to solar cycles. A formal statistical framework is presented for estimating and forecasting randomness in sunspot numbers on top of deterministic (including chaotic) models for solar cycles. The Fokker-Planck approach formulated assumes a specified long-term or secular variation in sunspot number over an underlying solar cycle via a driver function. The model then describes the observed randomness in sunspot number on top of this driver function. We consider a simple harmonic choice for the driver function, but the approach is general and can easily be extended to include other drivers which account for underlying physical processes and/or empirical features of the sunspot numbers. The framework is consistent during both solar maximum and minimum, and requires no parameter restrictions to ensure non-negative sunspot numbers. Model parameters are estimated using statistically optimal techniques. The model agrees both qualitatively and quantitatively with monthly sunspot data even with the simplistic representation of the periodic solar cycle. This framework should be particularly useful for solar cycle forecasters and is complementary to existing modeling techniques. An analytic approximation for the Fokker-Planck equation is presented, which is analogous to the Euler approximation, which allows for efficient maximum likelihood estimation of large data sets and/or when using difficult to evaluate driver functions.

  7. The asymmetry in sunspot area and magnetic flux variations in 1996-2004 extracted from the Solar Feature Catalogues

    NASA Astrophysics Data System (ADS)

    Zharkov, S. I.; Zharkova, V. V.

    2004-12-01

    This research utilizes a searchable Solar Feature Catalogue (SFC) for sunspots created from the SOHO/MDI full disk whitelight images and magnetograms in 1996-2004 using the automated pattern recognition techniques http://www.cyber.brad.ac.uk/egso/. A comparison of sunspot areas from the SFC with the averaged sunspot numbers published in the Sunspot Index Data Centre (SIDC) verified the detected sunspots with their correlation with sunspots areas on agiven day that revealed a very good detection accuracy of 86% for the whole period 1996-2003. The latitudinal (N-S) and longitudinal variations of sunspot areas, a total and resulting, or excess, magnetic flux are presented for the whole period of observations. The total sunspot areas measured from a single solar image have shown to have a strong Northern-Southern asymmetry that reveals the similar trend in the cumulative sunspot areas. At the start of the cycle from 1996 until 1999 the Northern hemisphere area trails the Southern one then followed by a bigger increase of the areas in the Northern hemisphere. The excess magnetic flux confined in sunspots also shows a significant N-S asymmetry being mostly negative in the Southern hemisphere and positive in the Northern one. However, towards the solar minimum in 1996 and in 2003-4 the excess flux becomes positive in the Southern and negative in the Northern hemispheres. These variations of total and excess magnetic fluxes during the solar cycle are compared with a few solar dynamo models.

  8. Possible Estimation of the Solar Cycle Characteristic Parameters by the 10.7 cm Solar Radio Flux

    NASA Astrophysics Data System (ADS)

    Lampropoulos, George; Mavromichalaki, Helen; Tritakis, Vasilis

    2016-03-01

    Two independent methods for estimating basic parameters of the solar cycle are presented. The first of them, the ascending-descending triangle method, is based on a previous work by Tritakis (Astrophys. Space Sci. 82, 463, 1982), which described how the fundamental parameters of a certain solar cycle could be predicted from the shape of the previous one. The relation between the two cycles before and after a specific 11-year solar cycle is tighter than between the two cycles belonging to the same 22-year solar cycle (even-odd cycle). The second is the MinimaxX method, which uses a significant relation in the international sunspot number between the maximum value of a solar cycle and its value 2.5 or 3 years (depending on the enumeration of the even or odd cycle) before the preceding minimum. The tests applied to Cycles 12 to 24 indicate that both methods can estimate the peak of the 11-year solar radio flux at a high confidence level. The data used in this study are the 10.7 cm solar radio flux since 1947, which have been extrapolated back to 1848 from the strong correlation between the monthly international sunspot numbers and the adjusted values of the 10.7 cm radio flux.

  9. 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.

    2016-02-01

    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.

  10. New methods for predicting the magnitude of sunspot maximum

    NASA Technical Reports Server (NTRS)

    Brown, G. M.

    1979-01-01

    Three new and independent methods of predicting the magnitude of a forthcoming sunspot maximum are suggested. The longest lead time is given by the first method, which is based on a terrestrial parameter measured during the declining phase of the preceding cycle. The second method, with only a slightly shorter foreknowledge, is based on an interplanetary parameter derived around the commencement of the cycle in question (sunspot minimum). The third method, giving the shortest prediction lead-time, is based entirely on solar parameters measured during the initial progress of the cycle in question. Application of all three methods to forecast the magnitude of the next maximum (Cycle 21) agree in predicting that it is likely to be very similar to that of Cycle 18.

  11. Borderline phylloides tumor in an 11-year-old girl.

    PubMed

    Selamzade, M; Gidener, C; Koyuncuoglu, M; Mevsim, A

    1999-07-01

    Phylloides tumor is an uncommon breast tumor in children. Only a few cases have been reported in the literature. A case of borderline phylloides tumor in an 11-year-old girl is described. PMID:10415310

  12. 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

  13. 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.

  14. 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.

  15. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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.

  17. The filamentary structure in sunspots

    NASA Astrophysics Data System (ADS)

    Hu, Y.-Q.

    1984-03-01

    An analytical model of the filamentary structure of sunspots is developed within the framework of magnetostatic-equilibrium theory and a small-perturbation assumption, neglecting convective motion and considering dynamic equilibrium only. Following the method of Hu et al. (1983), zeroeth and first order solutions of the nonaxisymmetric equilibrium equations are obtained, corresponding to the overall structure of the sunspot and to its filamentary structures. The dark filaments of the penumbral region are shown to be related to stronger magnetic fields, as observed by Beckers and Schroeter (1968).

  18. 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

  19. A Comparison Between Global Proxies of the Sun's Magnetic Activity Cycle: Inferences from Helioseismology

    NASA Astrophysics Data System (ADS)

    Broomhall, A.-M.; Nakariakov, V. M.

    2015-11-01

    The last solar minimum was, by recent standards, unusually deep and long. We are now close to the maximum of the subsequent solar cycle, which is relatively weak. In this article we make comparisons between different global (unresolved) measures of the Sun's magnetic activity to investigate how they are responding to this weak-activity epoch. We focus on helioseismic data, which are sensitive to conditions, including the characteristics of the magnetic field, in the solar interior. Also considered are measures of the magnetic field in the photosphere (sunspot number and sunspot area), the chromosphere and corona (10.7 cm radio flux and 530.3 nm green coronal index), and two measures of the Sun's magnetic activity closer to Earth (the interplanetary magnetic field and the galactic cosmic-ray intensity). Scaled versions of the activity proxies diverge from the helioseismic data around 2000, indicating a change in relationship between the proxies. The degree of divergence varies from proxy to proxy, with sunspot area and 10.7 cm flux showing only small deviations, while sunspot number, coronal index, and the two interplanetary proxies show much larger departures. In Cycle 24 the deviations in the solar proxies and the helioseismic data decrease, raising the possibility that the deviations observed in Cycle 23 are just symptomatic of a 22-year Hale cycle. However, the deviations in the helioseismic data and the interplanetary proxies increase in Cycle 24. Interestingly, the divergence in the solar proxies and the helioseismic data are not reflected in the shorter-term variations (often referred to as quasi-biennial oscillations) observed on top of the dominant 11-year solar cycle. However, despite being highly correlated in Cycle 22, the short-term variations in the interplanetary proxies show very little correlation with the helioseismic data during Cycles 23 and 24.

  20. Conservative Management of Cardiac Hemangioma for 11 Years.

    PubMed

    Gribaa, Rym; Slim, Mehdi; Neffati, Elyes; Boughzela, Essia

    2015-10-01

    Cardiac hemangiomas are benign tumors with an unpredictable natural history. Surgical resection is the treatment of choice; however, conservative management can be an alternative in some patients. We report a case of a left-sided cardiac hemangioma that we managed conservatively for 11 years without obvious major complications in the patient, an adult woman. PMID:26504439

  1. Conservative Management of Cardiac Hemangioma for 11 Years

    PubMed Central

    Slim, Mehdi; Neffati, Elyes; Boughzela, Essia

    2015-01-01

    Cardiac hemangiomas are benign tumors with an unpredictable natural history. Surgical resection is the treatment of choice; however, conservative management can be an alternative in some patients. We report a case of a left-sided cardiac hemangioma that we managed conservatively for 11 years without obvious major complications in the patient, an adult woman. PMID:26504439

  2. Continuum Intensity and Magnetic Field Relationship in Sunspots

    NASA Astrophysics Data System (ADS)

    Leonard, Trevor W.; Choudhary, D. P.

    2007-05-01

    The brightness (I) and magnetic field (B) distributions (I-B relationship) of sunspots are closely related. Several previous studies show that the relationship depends on the spot size, disk position, life time, and phase of the solar cycle in which it appears. The I-B relationship might also change from cycle to cycle. Many of the previous studies were conducted by single position measurements over the spot. Here, we present the results of a study of the I-B relationship using a uniform set of imaging observations of about 272 sunspots over the last two solar cycles at the San Fernando Observatory. The corresponding full disk magnetograms are from MDI-SOHO. The first result to be presented is the I-B relationship of sunspots. The second result is from an examination of the linear part of the I-B relationship, which shows that larger spots have a stiffer dependency compared to small spots. Another such dependency is more pronounced for the spots with a large umbra-penumbra ratio. Furthermore, the spots closer to the disk center have a stiffer I-B slope compared to the spots situated towards the limb. Finally, we explore the I-B properties of spots in relation to their corresponding solar hemispheres, as a function of their evolution history, dependence on their magnetic polarity, and any dependency on solar cycle. This work was partially supported by Cottrell College Science Award CC6496.

  3. Bimodality and the Hale cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1988-01-01

    Evidence is provided of a modulation of between 20 and 24 yr for the Hale cycle, and comparison of consecutive pairs of cycles strongly suggests that even-numbered cycles are preferentially paired with odd-numbered following cycles. The results indicate that cycles 22 and 23 form a new cyle pair. The sum of monthly mean sunspot numbers over consecutively paired sunspot cycles for Hale cycle 12 is found to be about 19,100 + or - 3000.

  4. Sunspot Tilt Angles Measured with MDI/SOHO and HMI/SDO

    NASA Astrophysics Data System (ADS)

    Li, J.; Ulrich, R. K.

    2015-12-01

    We present sunspot magnetic tilt angles measured from 1996 to the present time, spanning almost two solar cycles. Full disk magnetograms from MDI/SoHO and HMI/SDO are used in our study. The data cadence in our analyses is 96 minutes per day giving about 90 measurements of the tilt angles for each sunspot during the disk passage between -40 to +40 longitudinal degree. In addition to an automated computation, we use a scheme to visually examine each sunspot efficiently to check the tilt angle determinations. Such measurements not only confirm Joy's and Hale's laws, but also reveal the tilt angle variations during the sunspot lifetime, the effect of Coriolis force on the magnetic flux tubes, and the tilt angle dependence of the cycle progress. The measurements also provide uncertainties on the tilt angle measurements.

  5. 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.

    1998-01-01

    Samuel Heinrich Schwabe, the discoverer of the sunspot cycle, observed the Sun routinely from Desau, Germany during the interval of 1826-1869, averaging about 290 observing days per year. His yearly counts of 'clusters of spots' (or, more correctly, the yearly number of newly appearing sunspot groups) provided a simple means for describing the overt features of the sunspot cycle (i.e., the timing and relative strengths of cycle minimum and maximum). In 1848, Rudolf Wolf, a Swiss astronomer, having become aware of Schwabe's discovery, introduced his now familiar 'relative sunspot number' and established an international cadre of observers for monitoring the future behavior of the sunspot cycle and for reconstructing its past behavior (backwards in time to 1818, based on daily sunspot number estimates). While Wolf's reconstruction is complete (without gaps) only from 1849 (hence, the beginning of the modern era), the immediately preceding interval of 1818-1848 is incomplete, being based on an average of 260 observing days per year. In this investigation, Wolf's reconstructed record of annual sunspot number is compared against Schwabe's actual observing record of yearly counts of clusters of spots. The comparison suggests that Wolf may have misplaced (by about 1-2 yr) and underestimated (by about 16 units of sunspot number) the maximum amplitude for cycle 7. If true, then, cycle 7's ascent and descent durations should measure about 5 years each instead of 7 and 3 years, respectively, the extremes of the distributions, and its maximum amplitude should measure about 96 instead of 70. This study also indicates that cycle 9's maximum amplitude is more reliably determined than cycle 8's and that both appear to be of comparable size (about 130 units of sunspot number) rather than being significantly different. Therefore, caution is urged against the indiscriminate use of the pre-modern era sunspot numbers in long-term studies of the sunspot cycle, since such use may lead to

  6. 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.

  7. Re-examining Sunspot Tilt Angle to Include Anti-Hale Statistics

    NASA Astrophysics Data System (ADS)

    McClintock, B. H.; Norton, A. A.; Li, J.

    2014-12-01

    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 & 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.

  8. 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. PMID:16286289

  9. Solar Flare, CME, and Proton Event Rates Correlated with Sunspot Number

    NASA Astrophysics Data System (ADS)

    Winter, L. M.; Balasubramaniam, K. S.; Pernak, R.

    2015-12-01

    The newly revised sunspot number series allows for placing historical geoeffective storms in the context of several hundred years of solar activity. Using statistical analyses of the GOES X-ray and differential particle observations from the past ~30 years and the SOHO/LASCO CME catalog (1996-present), we present sunspot number dependent predictions for expected flare, SEP, and CME rates. In particular, we present X-ray flare rates as a function of sunspot number for the past three cycles. We also show, as in the attached figure, that the 1-8 Angstrom background flux is strongly correlated with sunspot number across solar cycles. Similarly, we show that the CME properties (e.g., velocity and width) are also correlated with sunspot number for cycles 23 and 24. Finally, SEP rates and background proton flux levels are also scaled to sunspot number. These rates will enable future predictions for geoeffective events and place historical storms in context of present solar activity.

  10. 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

  11. GLOBAL TWIST OF SUNSPOT MAGNETIC FIELDS OBTAINED FROM HIGH-RESOLUTION VECTOR MAGNETOGRAMS

    SciTech Connect

    Tiwari, Sanjiv Kumar; Venkatakrishnan, P.; Sankarasubramanian, K. E-mail: pvk@prl.res.in

    2009-09-10

    The presence of fine structures in sunspot vector magnetic fields has been confirmed from Hinode as well as other earlier observations. We studied 43 sunspots based on the data sets taken from ASP/DLSP, Hinode (SOT/SP), and SVM (USO). In this Letter, (1) we introduce the concept of signed shear angle (SSA) for sunspots and establish its importance for non-force-free fields. (2) We find that the sign of global {alpha} (force-free parameter) is well correlated with that of the global SSA and the photospheric chirality of sunspots. (3) Local {alpha} patches of opposite signs are present in the umbra of each sunspot. The amplitude of the spatial variation of local {alpha} in the umbra is typically of the order of the global {alpha} of the sunspot. (4) We find that the local {alpha} is distributed as alternately positive and negative filaments in the penumbra. The amplitude of azimuthal variation of the local {alpha} in the penumbra is approximately an order of magnitude larger than that in the umbra. The contributions of the local positive and negative currents and {alpha} in the penumbra cancel each other giving almost no contribution for their global values for the whole sunspot. (5) Arc-like structures (partial rings) with a sign opposite to that of the dominant sign of {alpha} of the umbral region are seen at the umbral-penumbral boundaries of some sunspots. (6) Most of the sunspots studied belong to the minimum epoch of the 23rd solar cycle and do not follow the so-called hemispheric helicity rule.

  12. 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.

  13. A Multi-instrument Analysis of Sunspot Umbrae

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  14. 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.

  15. Peculiarities of the fine structure of the 11-year cyclicity of solar activity

    SciTech Connect

    Voichishin, K.S.

    1981-01-01

    Substantiation is given for the concept of cyclicity, at the basis of which lie such characteristic features of heliophysical time series as stochasticity, discontinuity, and stability of the shape of the cycles. A conceptual and formal apparatus is developed for the description and analysis of cyclic oscillations. A simple model of cyclicity with disturbances of the phase structure and without them is analyzed on a heuristic level of rigor. The results of an investigation of the monthly fluctuations of Wolf numbers obtained within the framework of this model are presented. A connection between the quasideterminate amplitude component of the monthly fluctuations of Wolf numbers in the range of periods of from 2 to 15 months and the 11-year component is confirmed. It is shown that the fine structure of the 11-year averaged cycle of monthly average Wolf numbers is determined mainly by the almost-yearly quasideterminate component. The possibility of discontinuity (from cycle to cycle) in the quasi-determinate component of the above-mentioned fluctuations is pointed out.

  16. Causal relationships between solar and geomagnetic cycles

    NASA Astrophysics Data System (ADS)

    Ponyavin, D. I.

    2006-12-01

    Sunspots are sui generis "hot spots" that display the most responsive regions to solar cycle changes. Rudolf Wolf in 1848 derived a simple measure of solar cyclicity by counting a number of sunspots and sunspot groups at the solar disk. Edward Sabine in 1852 announced that geomagnetic cycle was "absolutely identical" to solar cycle. However geomagnetic and sunspot indices due to their different nature do not exhibit similar variations and often manifest out of phase behavior. Long-term sunspot and geomagnetic time-series were studied using wavelet transforms and recurrence plot techniques. We have analyzed similarities and relationships between sunspot and geomagnetic cycles in order to find recurrence, synchronization and phase differences on interannual scale. Predictive schemes of the current and future solar cycles using geomagnetic proxies were analyzed and discussed.

  17. Improvement of the photometric sunspot index and changes of the disk-integrated sunspot contrast with time

    NASA Technical Reports Server (NTRS)

    Froehlich, Claus; Pap, Judit M.; Hudson, Hugh S.

    1994-01-01

    The photometric sunspot index (PSI) was developed to study the effects of sunspots on solar irradiance. It is calculated from the sunspot data published in the Solar-Geophysical Data catalog. It has been shown that the former PSI models overestimate the effect of dark sunspots on solar irradiance; furthermore results of direct sunspot photometry indicate that the contrast of spots depends on their area. An improved PSI calculation is presented; it takes into account the area dependence of the contrast and calculates `true' daily means for each observation using the differential rotation of the spots. Moreover, the observations are screened for outliers which improves the homogeneity of the data set substantially, at least for the period after December 1981 when NOAA started to report data from a few instead of one to two stations. A detailed description of the method is provided. The correlation between the newly calculated PSI and total solar irradiance is studied for different phases of the solar cycles 21 and 22 using bi-variate spectral analysis. The results can be used as a `calibration' of PSI in terms of gain, the factor by which PSI has to be multiplied to yield the observed irradiance change. The factor changes with time from about 0.6 in 1980 to 1.1 in 1990. This unexpected result cannot be interpreted by a change of the contrast relative to the quiet Sun (as it is normally defined and determined by direct photometry) but rather as a change of the contrast between the spots and their surrounding as seen in total irradiance (integrated over the solar disk). This may partly be explained by a change in the ratio between the areas of the spots and the surrounding faculae.

  18. 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.

  19. 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.

  20. 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.

  1. 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).

  2. 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. PMID:17748272

  3. Digitization of sunspot drawings by Spörer made in 1861-1894

    NASA Astrophysics Data System (ADS)

    Diercke, A.; Arlt, R.; Denker, C.

    2015-01-01

    Most of our knowledge about the Sun's activity cycle arises from sunspot observations over the last centuries since telescopes have been used for astronomy. The German astronomer Gustav Spörer observed almost daily the Sun from 1861 until the beginning of 1894 and assembled a 33-year collection of sunspot data covering a total of 445 solar rotation periods. These sunspot drawings were carefully placed on an equidistant grid of heliographic longitude and latitude for each rotation period, which were then copied to copper plates for a lithographic reproduction of the drawings in astronomical journals. In this article, we describe in detail the process of capturing these data as digital images, correcting for various effects of the aging print materials, and preparing the data for contemporary scientific analysis based on advanced image processing techniques. With the processed data we create a butterfly diagram aggregating sunspot areas, and we present methods to measure the size of sunspots (umbra and penumbra) and to determine tilt angles of active regions. A probability density function of the sunspot area is computed, which conforms to contemporary data after rescaling.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Coronal Mass Ejections and the Solar Cycle Variation of the Sun's Open Flux

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    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.

  12. 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.

  13. Chromospheric seismology above sunspot umbrae

    NASA Astrophysics Data System (ADS)

    Snow, B.; Botha, G. J. J.; Régnier, S.

    2015-08-01

    Context. The acoustic resonator is an important model for explaining the three-minute oscillations in the chromosphere above sunspot umbrae. The steep temperature gradients at the photosphere and transition region provide the cavity for the acoustic resonator, which allows waves to be both partially transmitted and partially reflected. Aims: In this paper, a new method of estimating the size and temperature profile of the chromospheric cavity above a sunspot umbra is developed. Methods: The magnetic field above umbrae is modelled numerically in 1.5D with slow magnetoacoustic wave trains travelling along magnetic fieldlines. Resonances are driven by applying the random noise of three different colours - white, pink, and brown - as small velocity perturbations to the upper convection zone. Energy escapes the resonating cavity and generates wave trains moving into the corona. Line-of-sight integration is also performed to determine the observable spectra through SDO/AIA. Results: The numerical results show that the gradient of the coronal spectra is directly correlated with the chromosperic temperature configuration. As the chromospheric cavity size increases, the spectral gradient becomes shallower. When line-of-sight integration is performed, the resulting spectra demonstrate a broadband of excited frequencies that is correlated with the chromospheric cavity size. The broadband of excited frequencies becomes narrower as the chromospheric cavity size increases. Conclusions: These two results provide a potentially useful diagnostic for the chromospheric temperature profile by considering coronal velocity oscillations.

  14. 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. PMID:27015469

  15. 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

  16. 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

  17. 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.

    2016-03-01

    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.

  18. Solar Cycle 23: An Anomalous Cycle?

    NASA Astrophysics Data System (ADS)

    de Toma, Giuliana; White, Oran R.; Chapman, Gary A.; Walton, Stephen R.; Preminger, Dora G.; Cookson, Angela M.

    2004-07-01

    The latest SOHO VIRGO total solar irradiance (TSI) time series is analyzed using new solar variability measures obtained from full-disk solar images made at the San Fernando Observatory and the Mg II 280 nm index. We discuss the importance of solar cycle 23 as a magnetically simpler cycle and a variant from recent cycles. Our results show the continuing improvement in TSI measurements and surrogates containing information necessary to account for irradiance variability. Use of the best surrogate for irradiance variability due to photospheric features (sunspots and faculae) and chromospheric features (plages and bright network) allows fitting the TSI record to within an rms difference of 130 ppm for the period 1986 to the present. Observations show that the strength of the TSI cycle did not change significantly despite the decrease in sunspot activity in cycle 23 relative to cycle 22. This points to the difficulty of modeling TSI back to times when only sunspot observations were available.

  19. 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.

  20. The Earth's climate at minima of Centennial Gleissberg Cycles

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, Alexander; Feynman, Joan

    2015-10-01

    The recent extended, deep minimum of solar variability and the extended minima in the 19th and 20th centuries (1810-1830 and 1900-1920) are consistent with minima of the Centennial Gleissberg Cycle (CGC), a 90-100 year variation of the amplitude of the 11-year sunspot cycle observed on the Sun and at the Earth. The Earth's climate response to these prolonged low solar radiation inputs involves heat transfer to the deep ocean causing a time lag longer than a decade. The spatial pattern of the climate response, which allows distinguishing the CGC forcing from other climate forcings, is dominated by the Pacific North American pattern (PNA). The CGC minima, sometimes coincidently in combination with volcanic forcing, are associated with severe weather extremes. Thus the 19th century CGC minimum, coexisted with volcanic eruptions, led to especially cold conditions in United States, Canada and Western Europe.

  1. Modeling the Subsurface Structure of Sunspots

    NASA Astrophysics Data System (ADS)

    Moradi, H.; Baldner, C.; Birch, A. C.; Braun, D. C.; Cameron, R. H.; Duvall, T. L.; Gizon, L.; Haber, D.; Hanasoge, S. M.; Hindman, B. W.; Jackiewicz, J.; Khomenko, E.; Komm, R.; Rajaguru, P.; Rempel, M.; Roth, M.; Schlichenmaier, R.; Schunker, H.; Spruit, H. C.; Strassmeier, K. G.; Thompson, M. J.; Zharkov, S.

    2010-11-01

    While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do not yet allow helioseismology to probe the internal structure with sufficient confidence to distinguish between the monolith and cluster models, the development of physically realistic sunspot models are a priority for helioseismologists. This is because they are not only important indicators of the variety of physical effects that may influence helioseismic inferences in active regions, but they also enable detailed assessments of the validity of helioseismic interpretations through numerical forward modeling. In this article, we provide a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots. We then carry out a helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by Gizon et al. (2009a, 2009). We find that this sunspot is most probably associated with a shallow, positive wave-speed perturbation (unlike the traditional two-layer model) and that travel-time measurements are consistent with a horizontal outflow in the surrounding moat.

  2. Changes in the Bolometric Contrast of Sunspots

    NASA Astrophysics Data System (ADS)

    Chapman, G. A.; Cookson, A. M.; Dobias, J. J.

    1993-12-01

    We report on photometric observations of sunspots carried out with the Cartesian Full Disk Telescope (CFDT) at the San Fernando Observatory (SFO). The pixel size is 5.1 arc-sec and the wavelength for the data discussed here is 6723 Angstroms. Fluctuations in total solar irradiance due to sunspots are often modeled using a constant value of alpha, which we are calling the bolometric contrast of a sunspot. We have defined alpha_ {eff} as DEF/(2 times PSI), where DEF is the sunspot's photometric deficit relative to the quiet photosphere, and PSI is the digitally determined Photometric Sunspot Index (Willson et al., 1981). For 40 sunspot groups, we find that alpha_ {eff} = (0.276 +/- 0.051) + (3.22 +/- 0.34) 10(-5) A_s, where A_s is the corrected area of the sunspot in micro-hemispheres. The coefficient of determination is r(2) = 0.1936, which is significant at the p = 0.005 level. We also find that alpha_ {eff} is highly correlated with the ratio of umbral to total spot area (A_u/A_s). For 86 sunspot-days we find alpha_ {eff} = (0.219 +/- 0.018) + (0.643 +/- 0.028) (A_u/A_s) with the linear coefficient of determination r(2) = 0.859. This suggests that an improved PSI can be constructed from knowledge of a sunspot's umbral to total area ratio. The use of such an improved PSI or, better still, actual photometry should reduce the statistical noise in comparisons with spacecraft measurements of the total solar irradiance. This work has been partially supported by grants from NSF and NASA.

  3. 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.

  4. Visibility limit of naked-eye sunspots

    NASA Astrophysics Data System (ADS)

    Keller, H. U.; Friedli, T. K.

    1992-06-01

    Based on observations of 20 observers, a visibility limit for naked-eye sunspot observations has been calculated. A sunspot with a penumbral diameter of at least 41 arcsec and an umbral diameter of at least 15 arcsec can be detected by an average eye. An eyesight test was designed to solve the question whether the penumbral or the umbral diameter is conclusive for the visibility of a sunspot. The measured limit of 19.3 arcsec indicates that a combination of both is the determining factor.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Three Dimensional Chromospheric Temperature Structure of Sunspot

    NASA Astrophysics Data System (ADS)

    Choudhary, D. P.; Beck, C.; Rezaei, R.

    2014-12-01

    We have observed sunspots using the Spectropolarimeter for infrared and optical wavelength ranges at the Dunn Solar Telescope during 29 July to 4 August 2013. The data consists of full Stokes profiles in the Ca II 854.2 nm and Fe I 1.56 micron lines. The inversion of these Stokes spectra provides the magnetic, thermal and velocity structure at photospheric and chromospheric heights of sunspots. In this contribution, we present the results on the 3D thermal structure in the super-penumbral canopy of a well rounded sunspot, derived by a novel approach for the inversion of Ca II IR spectra. Tracing individual fibrils in the super-penumbral canopy, we find that about half of them form only short loops of a a few Mm length that return to the photosphere in the close surroundings of the sunspot instead of connecting to more remote magnetic network at the outer end of the moat flow.

  10. Three Dimensional Chromospheric Thermal Structure of Sunspot

    NASA Astrophysics Data System (ADS)

    Prasad Choudhary, Debi; Beck, Christian; Rezaei, R.

    2015-04-01

    We have observed sunspots using the Spectropolarimeter for infrared and optical wavelength ranges at the Dunn Solar Telescope during 29 July to 4 August 2013. The data consists of full Stokes profiles in the Ca II 854.2 nm and Fe I 1.56 micron lines. The inversion of these Stokes spectra provides the magnetic, thermal and velocity structure at photospheric and chromospheric heights of sunspots. In this contribution, we present the results on the 3D thermal structure in the super-penumbral canopy of a well rounded sunspot, derived by a novel approach for the inversion of Ca II IR spectra. Tracing individual fibrils in the super-penumbral canopy, we find that about half of them form only short loops of a a few Mm length that return to the photosphere in the close surroundings of the sunspot instead of connecting to more remote magnetic network at the outer end of the moat flow.

  11. 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.

  12. 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.

  13. 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).

  14. What the Long-Term Sunspot Record Tells Us About Space Climate

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.

    2004-01-01

    Direct observations of sunspots span the nearly 400 years since the time of Galileo. Dedicated observing programs at several observatories over the last 150 years have provided detailed information not only on the number of sunspots but on their sizes and positions as well. The data acquired by those original observers, and by those who have more recently brought those observations to light, provide important clues about the nature of the solar cycle and its contribution to space climate. The period of the cycle, the equator-ward drift of the active latitudes, the asymmetry between the rise to maximum and the fill to minimum, shifting asymmetries between northern and southern hemisphere activity, the tilt of active regions, and the increasing amplitude of the cycles since the Maunder Minimum are all well established. Other, less well established characteristics such as multi-cycle and short-term periodicities, often depend upon the method of data analysis. The strong correlation between sunspot statistics and other measures of solar activity, coupled with the length of the sunspot record, make these observations extremely valuable for characterizing and understanding space climate.

  15. Additional measurements of the high-latitude sunspot rotation rate /Research note/

    NASA Technical Reports Server (NTRS)

    Landman, D. A.; Takushi, J. T.

    1981-01-01

    Sunspot rotation rate measurements at high sunspot latitudes are reported for the period 1966-68, based on ten spots at latitudes greater than about 28 deg from H-alpha patrol records for this period. A sidereal rotation rate of 13.70 + or - 0.07 deg/day was found on the average, at 31.05 + or - 0.01 deg. Taken together, the full set of measurements in this latitude regime yield a rotation rate that is in excellent agreement with the result derived by Newton and Nunn (1951) from recurrent spots at lower latitudes throughout the six cycles from 1878 to 1944.

  16. Additional measurements of the high-latitude sunspot rotation rate /Research note/

    NASA Astrophysics Data System (ADS)

    Landman, D. A.; Takushi, J. T.

    1981-10-01

    Sunspot rotation rate measurements at high sunspot latitudes are reported for the period 1966-68, based on ten spots at latitudes greater than about 28 deg from H-alpha patrol records for this period. A sidereal rotation rate of 13.70 + or - 0.07 deg/day was found on the average, at 31.05 + or - 0.01 deg. Taken together, the full set of measurements in this latitude regime yield a rotation rate that is in excellent agreement with the result derived by Newton and Nunn (1951) from recurrent spots at lower latitudes throughout the six cycles from 1878 to 1944.

  17. Estimating 11-year solar UV variations using 27-day response as a guide to isolate trends in total column ozone

    NASA Technical Reports Server (NTRS)

    Keating, G. M.; Brasseur, G. P.; Chiou, L. S.; Hsu, N. C.

    1994-01-01

    The total column ozone response to 11-year solar ultraviolet (UV) variations is estimated here from the observed response to 27-day solar variations adjusted for the theoretical difference between the 27-day response and 11-year response. The estimate is tested by comparing two data sets where long-term drifts have been removed, the Nimbus 7 TOMS Version 6 total column ozone and the 280 nm core-to-wing ratio (a proxy for solar UV variations). The 365-day running means of data area-weighted between 40 deg N to 40 deg S latitude give a 1.9% ozone variation related to the 11-year solar cycle compared with the estimate of 1.8%. Estimates of linear trends were reduced by a factor of 2 by including solar effects. The standard deviation from the empirical model was reduced from 1.0 to 0.6 Dobson Units, by including the quasi-biennial oscillation (QBO), but the QBO did not significantly alter trend estimates. Both the ozone responses to 27-day and 11-year solar variations were considerably stronger than predicted by a 2-D theoretical model.

  18. The Big, the Bad, and the Ugly: Citizen scientist sunspot classification with Sunspot Zoo

    NASA Astrophysics Data System (ADS)

    Higgins, P. A.; O'Callaghan, D.; Perez-Suarez, D.; Roche, J.; Leka, K. D.; Barnes, G.; Slater, G. L.; Murray, S.; Gallagher, P.

    2013-12-01

    It is not currently possible to reliably forecast the occurrence of solar flares. To date, one of the best predictors for the occurrence of flares is that a sunspot group has already produced large flares. Without knowledge of prior activity, the best predictions are generally achieved by systems using human-based visual recognition (e.g., human expert forecasters). This project explores the possibility of using `the crowd' to feed information to a forecasting algorithm to improve the current state of flare prediction. The aims of Sunspot Zoo are: to create a crowd-sourced sunspot group complexity ranking; to test if complexity predicts flaring; to stimulate interest in solar physics and citizen science in school students and the public. Sunspot Zoo will soon be made available through Zooniverse.org to allow large-scale participation. An outreach program will bring Sunspot Zoo to schools in Ireland this Autumn.

  19. 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.

    2016-06-01

    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_{ISNv1}], 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_{ISNv1}, 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 the test

  20. 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.

    2016-06-01

    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 the

  1. The Ten-Rotation Quasi-periodicity in Sunspot Areas

    NASA Astrophysics Data System (ADS)

    Getko, R.

    2014-06-01

    Sunspot-area fluctuations over an epoch of 12 solar cycles (12 - 23) are investigated in detail using wavelets. Getko ( Universal Heliophysical Processes, IAU Symp. 257, 169, 2009) found three significant quasi-periodicities at 10, 17, and 23 solar rotations, but two longer periods could be treated as subharmonics of the ten-rotation quasi-periodicity. Therefore we focused the analysis on the occurrence of this quasi-periodicity during the low- and high-activity periods of each solar cycle. Because of the N - S asymmetry, each solar hemisphere was considered separately. The skewness of each fluctuation-probability distribution suggests that the positive and negative fluctuations could be examined separately. To avoid the problem that occurs when a few strong fluctuations create a wavelet peak, we applied fluctuation transformations for which the amplitudes at the high- and the low-activity periods are almost the same. The wavelet analyses show that the ten-rotation quasi-periodicity is mainly detected during the high-activity periods, but it also exists during a few low-activity periods. The division of each solar hemisphere into 30∘-wide longitude bins and the wavelet calculations for the areas of sunspot clusters belonging to these 30∘ bins enable one to detect longitude zones in which the ten-rotation quasi-periodicity exists. These zones are present during the whole high-activity periods and dominate the integrated spectra.

  2. 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.

  3. 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.

  4. Variation in sunspot properties between 1999 and 2014

    NASA Astrophysics Data System (ADS)

    Rezaei, R.; Beck, C.; Lagg, A.; Borrero, J. M.; Schmidt, W.; Collados, M.

    2015-06-01

    Aims: We study the variation in the magnetic field strength, area, and continuum intensity of umbrae in solar cycles 23 and 24. Methods: We analyzed a sample of 374 sunspots observed from 1999 until 2014 with the Tenerife Infrared Polarimeter at the German Vacuum Tower Telescope and the Facility InfRared Spectropolarimeter at the Dunn Solar Telescope. The sample of field strength, area, and intensities was used to trace any long-term or cyclic trend of umbral properties in the last 15 years. Results: Sunspots are systematically weaker, that is, have a weaker field strength and stronger continuum intensity, toward the end of cycle 23 than they had at the maximum of cycle 23. The linear trend reverses with the onset of cycle 24. We find that the field strength decreases in the declining phase of cycle 23 by about 112 (± 16) G yr-1, while it increases in the rising phase of cycle 24 by about 138 (± 72) G yr-1. The umbral intensity shows the opposite trend: the intensity increases with a rate of 0.7 (± 0.3)% of Ic yr-1 toward the end of cycle 23 and decreases with a rate of 3.8 (± 1.5)% of Ic yr-1 toward the maximum of cycle 24. The distribution of the umbral maximum field strength in cycle 24 is similar to that of cycle 23, but is slightly shifted toward lower values by about 80 G, corresponding to a possible long-term gradient in umbral field strength of about 7 ± 4 G yr-1. If instead of the maximum umbral field we consider the average value over the entire umbra, the distribution shifts by about 44 Gauss. Conclusions: The umbral brightness decreases in the rising stage of a solar cycle, but increases from maximum toward the end of the cycle. Our results do not indicate a drastic change of the solar cycle toward a grand minimum in the near future.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  7. 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.

  8. Properties of Photospheric Bright Points outside Sunspots

    NASA Astrophysics Data System (ADS)

    Qu, H. X.; Yang, Y. F.; Feng, S.; Wang, F.; Deng, H.; Ji, K. F.

    2015-09-01

    Photospheric bright points are tiny bright features located in intergranular lanes. They are widely believed as the foot points of magnetic flux tubes. In this paper, various properties of bright points outside NOAA 11598 sunspots are analyzed using the TiO-band data detected by the 1-m New Vacuum Solar Telescope of Yunnan Observatories, which is located at the Fuxian Solar Physics Observing Station, Yunnan Province. We divide the periphery of the sunspot into four annular regions based on the dilation technology of image morphology. Then, a Laplacian and morphological dilation algorithm is used to identify bright points, and a three-dimensional segment algorithm is applied to track the evolution of bright points. Finally, we detect the parameters of the bright points in the four annular regions, including the density, intensity, size, shape, and velocity. Statistical results show that the density, size, and velocity of photospheric bright points are obviously affected by the strong magnetic fields of sunspots, and their peak values are in the second region instead of the closest region of the sunspot. The bright points decrease their densities and sizes, but increase their velocities with the distance away from the sunspot center. Additionally, the maximum intensity contrast presents the decreasing trend. However, the bright point shapes are basically invariant, and independent of this distance.

  9. p-Mode Interaction with Sunspots

    NASA Astrophysics Data System (ADS)

    Cally, P. S.; Moradi, H.; Rajaguru, S. P.

    2016-02-01

    This chapter brings together two of the prominent features of our star the Sun: its well-developed p-mode spectrum of global oscillations excited by near-surface convection, and its magnetic activity famously represented by sunspots. Modern developments in observations of p-mode and sunspot magnetic field interactions have helped bridge the gap between theory and observations: both the oscillations within a sunspot and in the immediate surroundings of the sunspot appear to be due to magnetohydrodynamics waves driven by p-modes with characteristic spatial patterns of frequencies intimately related to magnetic inclination and the height variation of the plasma p = 1 layer. The chapter makes the case that the behavior of waves in sunspots is dominated by four processes: the ramp effect; fast-to-slow mode conversion; fast-wave reflection; and fast-to-Alfvén mode conversion. The chapter then discusses some of the major developments in helioseismic forward and inverse modeling that have occurred over the last decade.

  10. Starspot-Induced Radial Velocity Jitter During a Stellar Cycle

    NASA Astrophysics Data System (ADS)

    Korhonen, Heidi; Andersen, Jan Marie; Järvinen, Silva

    2014-04-01

    Late-type stars exhibit cool regions on their surface, the stellar equivalent of sunspots. These dark starspots can also mimic the radial velocity variations caused by orbiting planets, making it at times difficult to distinguish between planets and activity signatures. The amount of spots on the Sun and other cool stars changes cyclically during an activity cycle, which has length varying from about a year to longer than the solar 11 years. In this work we investigate the influence of varying amount of starspots on the sparsely sampled radial velocity observations - which are the norm in the radial velocity studies searching for exoplanets on wide orbits. We study two simulated cases: one with a random spot configuration, and one where the spot occurrence is concentrated. In addition we use Doppler images of young solar analogue V889 Her as a high activity case.

  11. The Discontinuity Circa 1885 in the Group Sunspot Number

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.; Ling, A. G.

    2016-02-01

    On average, the international sunspot number ( RI) is 44 % higher than the group sunspot number ( RG) from 1885 to the beginning of the RI series in 1700. This is the principal difference between RI and RG. Here we show that this difference is primarily due to an inhomogeneity in the Royal Greenwich Observatory (RGO) record of sunspot groups (1874 - 1976) used to derive observer normalization factors (called k-factors) for RG. Specifically, annual RGO group counts increase relative to those of Wolfer and other long-term observers from 1876 - 1915. A secondary contributing cause is that the k-factors for observers who began observing before 1884 and overlapped with RGO for any years during 1874 - 1883 were not based on direct comparison with RGO but were calculated using one or more intermediary or additional observers. We introduce R_{GC} by rectifying the RGO group counts from 1874 - 1915 and basing k-factors on direct comparison with RGO across the 1885 discontinuity, which brings the RG and RI series into reasonable agreement for the 1841 - 1885 interval (after correcting RI for an inhomogeneity from 1849 - 1867 (to give R_{IC})). Comparison with an independently derived backbone-based reconstruction of RG ( R_{BB}) indicates that R_{GC} over-corrects R_{BB} by 4 % on average from 1841 - 1925. Our analysis suggests that the maxima of Cycles 10 (in 1860), 12 (1883/1884), and 13 (1893) in the R_{IC} series are too low by ≈ 10 %.

  12. Photoelectric observations of propagating sunspot oscillations

    NASA Technical Reports Server (NTRS)

    Lites, B. W.; White, O. R.; Packman, D.

    1982-01-01

    Repeated intensity and velocity images of a large, isolated sunspot in both the chromospheric Ca II 8542 A and photospheric Fe I 5576 line were performed. It is shown by means of a movie of the digital data for the chromospheric line that a relationship exists between the propagating umbral disturbances and the running penumbral waves. Power spectra of the oscillations show a sharp peak at a period of about 170 sec in both the velocity and intensity signals, and the oscillations at any point in the sunspot are found to be very regular. The phase relationship between the velocity and the intensity of the chromospheric oscillations contrasts with that for the quiet sun. The mechanical energy flux carried by the observed umbral disturbances does not appear to be a significant contributor to the overall energy budget of the sunspot or the surrounding active region.

  13. 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.

  14. Facular-sunspot coverage relation derived by MDI magnetograms

    NASA Astrophysics Data System (ADS)

    Criscuoli, Serena

    2016-05-01

    We employ MDI full-disk magnetograms acquired during Cycle 23 and at the beginning of Cycle 24 to investigate the relation between the filling factor of magnetic elements characterized by different amount of magnetic flux and located at different angular distance 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 6-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 6-months averaged data show asymmetries between the ascending and the descending phase.

  15. An Improved Determination of the Area Ratio of Faculae to Sunspots

    NASA Astrophysics Data System (ADS)

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

    2001-07-01

    We report new results on the ratio of facular area to sunspot area from a program of continuing photometric observations using the Cartesian Full Disk Telescope No. 1 (CFDT1) at the San Fernando Observatory (SFO). The facular areas are determined from images obtained with a 1 nm bandpass Ca II K line filter, and sunspot areas are determined from red images at 672 nm with a 10 nm bandpass filter. On the K line images faculae were identified by pixels that had a contrast equal to or greater than 4.8% divided by μ. Previously, we found that the average facular-to-spot area ratio was 16.7+/-0.5 during the latter part of solar cycle 22 and that there was a small but statistically significant rise in the ratio with time. If we take an average from the beginning of the K line data (mid-1988) until the middle of 1996, excluding days of zero sunspot area, the average ratio is 16.4+/-0.4. The average ratio from mid-1996 to the end of 1999 November is 12.6+/-0.5. Including days of zero sunspot area for these same intervals we find average ratios of 16.8+/-0.5 and 13.2+/-0.6, respectively. We have recently reprocessed our K line images, which have been photometrically ``cleaned.'' We can now reliably identify facular pixels with a contrast criterion of 2.4%, resulting in an increase in the average facular-to-spot ratio of approximately 3. The average facular and sunspot areas for cycle 23 are significantly lower than for cycle 22.

  16. An essay on sunspots and solar flares

    NASA Astrophysics Data System (ADS)

    Akasofu, S.-I.

    1984-11-01

    The author reviews some of the recent findings on large-scale magnetic fields and sunspots. Then, instead of relying on the hypothetical flux tube beneath the photosphere, he considers an amplification process of the observed large-scale fields by a dynamo process on the basis of the observed and possible photospheric shear flows. Thus, the photosphere is considered as an active medium, rather than the passive medium through which the hypothetical flux tube merely penetrates. Specifically, the author considers the dynamo process associated with vortex motions which can supply the power needed for the formation of sunspots from the observed weak field and the power needed for solar flares.

  17. 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.

  18. REVISITED SUNSPOT DATA: A NEW SCENARIO FOR THE ONSET OF THE MAUNDER MINIMUM

    SciTech Connect

    Vaquero, Jose M.; Gallego, M. C.; Usoskin, Ilya G.; Kovaltsov, Gennady A. E-mail: maricruz@unex.es E-mail: gen.koval@mail.ru

    2011-04-20

    The Maunder minimum forms an archetype for the Grand minima, and detailed knowledge of its temporal development has important consequences for the solar dynamo theory dealing with long-term solar activity evolution. Here, we reconsider the current paradigm of the Grand minimum general scenario by using newly recovered sunspot observations by G. Marcgraf and revising some earlier uncertain data for the period 1636-1642, i.e., one solar cycle before the beginning of the Maunder minimum. The new and revised data dramatically change the magnitude of the sunspot cycle just before the Maunder minimum, from 60-70 down to about 20, implying a possibly gradual onset of the minimum with reduced activity started two cycles before it. This revised scenario of the Maunder minimum changes, through the paradigm for Grand solar/stellar activity minima, the observational constraint on the solar/stellar dynamo theories focused on long-term studies and occurrence of Grand minima.

  19. The Heliosphere Through the Solar Activity Cycle

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  20. 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.

  1. Further Studies of the Bolometric Contrast of Sunspots

    NASA Astrophysics Data System (ADS)

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

    2002-05-01

    Daily images are obtained at the San Fernando Observatory (SFO) of the full solar disk with two photometric telescopes, CFDT1 and CFDT2. CFDT1 produces images with 5" x 5" pixels while CFDT2 produces images with 2.5" x 2.5" pixels. In a previous paper (Chapman et al. 1994) we reported on the bolometric contrast of sunspots using red images from CFDT1. The bolometric contrast, α eff, is heuristically defined as α eff = Dr/(2 x PSI), where Dr is the photometric deficit in the red image and PSI is the usual Photometric Sunspot Index. Here, we will report on studies of the bolometric contrast from red CFDT2 images. We will examine the effects of higher spatial resolution and we will look for differences in the bolometric contrast between cycle 22 and 23. This research was partially supported by grants from NSF (ATM-9912132) and NASA (NAG5-7191). Reference: Chapman, G.A., Cookson, A.M. and Dobias, J.J. 1994, Ap.J. 432, 403.

  2. 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.

  3. The long-term oscillations in sunspots and related inter-sunspot sources in microwave emission

    NASA Astrophysics Data System (ADS)

    Bakunina, I. A.; Abramov-Maximov, V. E.; Smirnova, V. V.

    2016-02-01

    This work presents the microwave long-term oscillations with periods of a few tens of minutes obtained from Nobeyama radioheliograph (NoRH) at frequency 17 GHz. In two active regions the fluctuations of radio emission of different types of intersunspot sources (ISS) (compact and extended) were compared with the fluctuations in magnetic fields of sunspots. Common periods in variations of microwave emission of different type of sources and magnetic field of sunspots were discovered. The delay of 17 minutes was revealed for oscillations of the extended ISS with respect to variations of magnetic field of its tail sunspot. The model of the sunspot magnetic structure based on the concept of three magnetic fluxes for explanation of this fact is discussed.

  4. The eight-schwabe-cycle pulsation

    NASA Astrophysics Data System (ADS)

    Richard, Jean-Guillaume

    2004-09-01

    The shape of the Sun’s secular activity cycle is found to be a saw-tooth curve. The additional Schwabe cycle 4‧ (1793 1799) suggested by Usoskin, Mursula, and Kovaltsov (2001a) is taken into account in the telescopic sunspot record (1610 2001). Instead of a symmetrical Gleissberg cycle, a saw-tooth of exactly eight Schwabe sunspot maxima (‘Pulsation’) is found. On average, the last sunspot maximum of an eight-Schwabe-cycle saw-tooth pulsation has been about three times as high as its first maximum. The Maunder Minimum remains an exception to this pattern. The Pulsation is defined as a secular-scale envelope of Schwabe-cycle maxima, whereas the Gleissberg cycle is a result of long-term smoothing of the sunspot series.

  5. Magnetic Splitting of Molecular Lines in Sunspot

    NASA Astrophysics Data System (ADS)

    Berdyugina, S. V.; Frutiger, C.; Solanki, S. K.

    A study of molecular lines in sunspots is of particular interest because of their high temperature and pressure sensitivity. Many of them are also magnetically sensitive, but this was not yet widely investigated. With high-resolution, high signal-to-noise Fourier spectroscopy in four Stokes parameters now available, the use of molecular lines for studying the structure of sunspots brings real gains. One is the extension of spot models, including magnetic field, up to layers, where atomic lines suffer from NLTE effects but molecules can still be treated in the LTE approximation. Equally important is the fact that since molecular lines are extremely temperature sensitive they can be used to probe the thermal and magnetic structure of the coolest parts of sunspots. We present calculations of splitting and the Stokes parameters for a number of molecular lines in the visible and near-infrared regions. Our first selections are the green system of MgH A2Π-X2σ and the TiO triplet α, γ' and γ systems as the most studied band systems in the sunspot spectrum. The calculations involve different regimes of the molecular Zeeman effect, up to the complete Paschen-Back effect for individual lines. We look for molecular lines which can be used along with atomic lines to derive magnetic, thermal and dynamic properties of the umbra.

  6. Fine Structure and Dynamics of Sunspot Penumbra

    NASA Astrophysics Data System (ADS)

    Ryutova, M.; Berger, T.; Title, A.

    2007-08-01

    A mature sunspot is usually surrounded by a penumbra: strong vertical magnetic field in the umbra, the dark central region of sunspot, becomes more and more horizontal toward the periphery forming an ensemble of a thin magnetic filaments of varying inclinations. Recent high resolution observations with the 1-meter Swedish Solar Telescope (SST) on La Palma revealed a fine substructure of penumbral filaments and new regularities in their dynamics.1 These findings provide both the basis and constraints for an adequate model of the penumbra whose origin still remains enigmatic. We present results of recent observations obtained with the SST. Our data, taken simultaneously in 4305 Å G-band and 4396 Å continuum bandpasses and compiled in high cadence movies, confirm previous results and reveal new features of the penumbra. We find e.g. that individual filaments are cylindrical helices with a pitch/radius ratio providing their dynamic stability. We propose a mechanism that may explain the fine structure of penumbral filaments, the observed regularities, and their togetherness with sunspot formation. The mechanism is based on the anatomy of sunspots in which not only penumbra has a filamentary structure but umbra itself is a dense conglomerate of twisted interlaced flux tubes.

  7. 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.

  8. 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.

  9. A Note on Solar Cycle Length Estimates

    NASA Astrophysics Data System (ADS)

    Vaquero, J. M.; García, J. A.; Gallego, M. C.

    2006-05-01

    Recently, new estimates of the solar cycle length (SCL) have been calculated using the Zurich Sunspot Number (R Z) and the Regression-Fourier-Calculus (RFC)-method, a mathematically rigorous method involving multiple regression, Fourier approximation, and analytical expressions for the first derivative. In this short contribution, we show estimates of the solar cycle length using the RFC-method and the Group Sunspot Number (R G) instead the R Z. Several authors have showed the advantages of R G for the analysis of sunspot activity before 1850. The use of R G solves some doubtful solar cycle length estimates obtained around 1800 using R Z.

  10. 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.

  11. 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.

  12. Successful treatment of florid cutaneous warts with intravenous cidofovir in an 11-year-old girl.

    PubMed

    Cusack, Caitriona; Fitzgerald, Deborah; Clayton, Timothy M; Irvine, Alan D

    2008-01-01

    Cutaneous warts, commonly seen in children and the immunosuppressed are socially distressing and are often resistant to traditional treatments. Here, we report an 11-year-old girl with bilateral florid verrucous lesions on her hands, feet and chin, which were refractory to a number of standard treatments including cryotherapy, cantharidin preparations, topical salicylic acid, surgical debulking techniques, oral Cimetidine, and topical and intralesional Cidofovir. As the disfiguring lesions had a marked adverse effect on her quality of life, a trial of IV Cidofovir was instituted. We administered five cycles of IV Cidofovir with a 1-week interval between the first and second treatment, followed by 2-week intervals thereafter. This regime was well tolerated and we report dramatic resolution of the lesions with persistent clearance 6 months after completion of the fifth infusion. Resolution of recalcitrant warts with IV Cidofovir has been reported in a limited number of cases. Our experience supports its efficacy in this setting, and to the best of our knowledge this is the first report of successful treatment of cutaneous warts with IV Cidofovir in a pediatric case. PMID:18577053

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    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.

  14. 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.

  15. On the contribution of sunspots to the observed frequency shifts of solar acoustic modes

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    Activity-related variations in the solar oscillation properties have been known for 30 years. However, the relative importance of the different contributions to the observed variations is not yet fully understood. Our goal is to estimate the relative contribution from sunspots to the observed activity-related variations in the frequencies of the acoustic modes. We use a variational principle to relate the phase differences induced by sunspots on the acoustic waves to the corresponding changes in the frequencies of the global acoustic oscillations. From the sunspot properties (area and latitude as a function of time), we are able to estimate the spot-induced frequency shifts. These are then combined with a smooth frequency shift component, associated with long-term solar-cycle variations, and the results compared with the frequency shifts derived from the Global Oscillation Network Group (GONG) data. The result of this comparison is consistent with a sunspot contribution to the observed frequency shifts of roughly 30%, with the remaining 70% resulting mostly from a global, non-stochastic variation, possibly related to the changes in the overall magnetic field. Moreover, analysis of the residuals obtained after the subtraction of the model frequency shifts from the observations indicates the presence of a 1.5-yr periodicity in the data in phase with the quasi-biennial variations reported in the literature.

  16. On the contribution of sunspots to the observed frequency shifts of solar acoustic modes

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    Activity-related variations in the solar oscillation properties have been known for 30 years. However, the relative importance of the different contributions to the observed variations is not yet fully understood. Our goal is to estimate the relative contribution from sunspots to the observed activity-related variations in the frequencies of the acoustic modes. We use a variational principle to relate the phase differences induced by sunspots on the acoustic waves to the corresponding changes in the frequencies of the global acoustic oscillations. From the sunspot properties (area and latitude as a function of time), we are able to estimate the spot-induced frequency shifts. These are then combined with a smooth frequency shift component, associated with long-term solar-cycle variations, and the results compared with the frequency shifts derived from the Global Oscillation Network Group data. The result of this comparison is consistent with a sunspot contribution to the observed frequency shifts of roughly 30 per cent, with the remaining 70 per cent resulting mostly from a global, non-stochastic variation, possibly related to the changes in the overall magnetic field. Moreover, analysis of the residuals obtained after the subtraction of the model frequency shifts from the observations indicates the presence of a 1.5-yr periodicity in the data in phase with the quasi-biennial variations reported in the literature.

  17. 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.

  18. Observations of changes in the bolometric contrast of sunspots

    NASA Technical Reports Server (NTRS)

    Chapman, G. A.; Cookson, A. M.; Dobias, J. J.

    1994-01-01

    Rapid changes in the total solar irradiance from space borne sensors are largely due to the passage of large sunspots across the disk. The effect of sunspots has often been modeled, using ground-based observations, by the use of a sunspot index such as the PSI, which assumes that all sunspots have the same thermal structure, which remains constant with time. In this paper, we report on photometric observations of sunspot groups that show significant differences in their mean bolometric contrast ( up to a factor of 2) and some of which show cooling or warming during their disk transit. Most of these changes can be ascribed to the changing ratio of umbral-to-prenumbral area. By measuring the mean temperature or bolometric contrast, together with corrected (hemispherical) areas, we can determine the instantaneous solar luminosity fluctuation and its diurnal change due to individual sunspot groups. These results show that the use of solar indices based on estimates of sunspot area and fixed sunspot contrast, such as the photometric sunspot index, do not remove all of the significant sunspot effects from satellite measurements of the total solar irradiance.

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

    NASA Astrophysics Data System (ADS)

    Criscuoli, S.

    2016-07-01

    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.

  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. Correlation between the sunspot number and tropospheric refractivity in a tropical environment

    NASA Astrophysics Data System (ADS)

    Yusuf, Najib; Ayantunji, B. G.

    2015-10-01

    In this paper, a study of the tropospheric surface refractivity relationship with sunspots number variability on daily scale was carried out in a tropical region in Nigeria. The data was averaged to hourly mean from the initial five minutes update cycle and then to daily mean using spread sheet. The dependence of surface radio refractivity on sunspots number for the period considered in this work was established using linear regression coefficient and the results for Lagos and Anyigba are R2=0.019, R2=0.004, R2=0.010, R2=0.000 and R2=0.000 for 2007, 2008, 2009, 2010 and 2011 and R2=0.089, R2=0.027 and R2=0.007 for 2010, 2011 and 2012 respectively. However, when the spotless days were filtered the regression coefficient was obtained to be R2=0.145, R2=0.01261, R2=0.00001, R2=0.0012 and R2=0.062 for 2007, 2008, 2009, 2010 and 2011 for Lagos and R2=0.1155, R2=0.0261 and R2=0.0071 for 2010, 2011 and 2012 for Anyigba respectively. Meteorological data from 2007 to 2011 was employed for Lagos while meteorological data from 2010 to 2012 was employed for Anyigba. Sunspot data was also obtained from Royal Observatory of Belgium for the period under study. Results obtained show no correlation between Sunspot number and surface refractivity. The sunspot number data was filtered to remove noise due to spotless days. The result obtained after filtering did not show any significant difference.

  2. 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

  3. 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.

  4. Vertical gradients of sunspot magnetic fields

    NASA Astrophysics Data System (ADS)

    Hagyard, M. J.; Teuber, D.; West, E. A.; Tandberg-Hanssen, E.; Henze, W., Jr.; Beckers, J. M.; Bruner, M.; Hyder, C. L.; Woodgate, B. E.

    1983-04-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  5. Vertical gradients of sunspot magnetic fields

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.; Teuber, D.; West, E. A.; Tandberg-Hanssen, E.; Henze, W., Jr.; Beckers, J. M.; Bruner, M.; Hyder, C. L.; Woodgate, B. E.

    1983-01-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  6. 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.

  7. Reduced Coronal Emission Above Large Isolated Sunspots

    NASA Astrophysics Data System (ADS)

    Ryabov, B. I.; Gary, D. E.; Peterova, N. G.; Shibasaki, K.; Topchilo, N. A.

    2015-01-01

    We analysed specific regions of reduced soft X-ray and microwave emission in five large isolated sunspots. The Nobeyama Radioheliograph 17 GHz observations reveal a local depression of microwave brightness in the peripheral area of the sunspots. The depression regions appear light (weak absorption) in the He 10830 Å line in areas with extended (open) field lines, as indicated by potential field source surface model (PFSS) extrapolations up to 1.5 R⊙. The observed depressions of 3 - 8 % in ordinary mode at 17 GHz are interpreted as resulting from free-free emission when the plasma density is lower by 5 - 10 %. Our model estimates show that the decrease in density in both the coronal and the lower layers above the depression region accounts for the depression. These depression regions lend themselves well to marking the location of outward plasma motions.

  8. 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.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.

  11. A photoelectric guide for sunspot images

    NASA Astrophysics Data System (ADS)

    Druzhinin, S. A.; Maslov, I. L.; Pevtsov, A. A.

    A photoelectric guide designed to directly handle sunspot images is described. A quadrant photodiode (serving as the photodetector) is placed in the beam reflected from the Dove prism face. The actuators are two plane-parallel plates attached to low-inertia electromagnetic drives, ensuring a high frequency (up to 3 Hz) of control action in response to image motion. The guide is placed in front of the spectrograph entrance slit and can be used with any standard AZU-5 telescope.

  12. Returning magnetic flux in sunspot penumbrae

    NASA Astrophysics Data System (ADS)

    Ruiz Cobo, B.; Asensio Ramos, A.

    2013-01-01

    Aims: We study the presence of reversed polarity magnetic flux in sunspot penumbra. Methods: We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based on a principal component decomposition of the Stokes profiles. The resulting Stokes profiles were inverted to infer the magnetic field vector using SIR. Results: We find, for the first time, reversed polarity fields at the border of many bright penumbral filaments in the whole penumbra.

  13. Photoelectric observations of propagating sunspot oscillations

    SciTech Connect

    Lites, B.W.; White, O.R.; Packman, D.

    1982-02-01

    The Sacramento Park Observatory Vacuum Tower Telescope and diode array were used to make repeated intensity and velocity images of a large, isolated sunspot in both a chromospheric (lambda8542 Ca II) and a photospheric (lambda5576 Fe I) line. The movie of the digital data for the chromospheric line shows clearly a relationship between the propagating umbral disturbances and the running penumbral waves. The velocities for transverse propagating of the umbral and penumbral disturbances are 60--70 km s/sup -1/ and 20--35 km s/sup -1/, respectively. Power spectra of the oscillations show a sharp peak at a period of about 170 s in both the velocity and intensity signals. The rms velocity fluctuation of this power peak is 0.26 km s/sup -1/. The oscillations at any given point in the sunspot are very regular, and the phase relationship between the velocity and intensity of the chromospheric oscillations is radically different than that for the quiet Sun. Our preliminary interpretation of the phase relationship involves acoustic waves with wave vector directed downwards along the magnetic field lines; however, this interpretation relies on assumptions involved in the data reduction scheme. The mechanical energy flux carried by the observed umbral disturbances does not appear to be a significant contributor to the overall energy budget of the sunspot or the surrounding active region.

  14. Magnetic structure of sunspot under the photosphere

    NASA Astrophysics Data System (ADS)

    Kirichek, Elena A.; Solov'ev, Alexandr A.

    2010-11-01

    In recent years, the local helioseismology has become a highly effective tool for investigating subphotospheric layers of the Sun, which can yield fairly detailed distributions of the subphotospheric temperatures and large-scale plasma flows based on the spectra of the oscillations observed at the photospheric layers and the observed peculiarities of propagation of magnetoacoustic waves in this medium (Zhao et al. (2001), Kosovichev (2006)). Unfortunately, the effects of temperature and the magnetic field on the wave propagation speed have not yet been separated Kosovichev (2006), so that the structure of the sunspot magnetic field in deep layers, beneath the photosphere, remains a subject of purely theoretical analysis. In his analysis of some theoretical models of the subphotospheric layers of sunspots based on recent helioseismological data, Kosovichev (2006) concluded that Parker's (“spaghetti”) cluster model Parker (1979) is most appropriate. In this model, the magnetic flux in the sunspot umbra is concentrated into separate, strongly compressed, vertical magnetic flux tubes that are interspaced with plasma that is almost free of magnetic field; the plasma can move between these tubes.

  15. 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.

  16. Convective flows around sunspot-like objects

    NASA Technical Reports Server (NTRS)

    Fox, Peter A.; Sofia, Sabatino; Chan, Kwing L.

    1991-01-01

    Calculations of convective flows around objects in the outer layers of the sun that have characteristics similar to those of sunspots are presented. It is assumed that these objects are allowed to radiatively exchange heat with their surroundings, but convective motions and exchange are absent. The flow structure around the object, and the question of the overall balance or redistribution of the emerging heat flux as suggested by earlier empirical models are discussed. In all the cases studied, there was a significant increase in the kinetic energy flux and thus the lateral transport of the energy flux surrounding the object. This mainly occurred below the object to allow the heat to appear at the surface, with some time delay. The percentage reduction in the specific intensity agrees well with the observed deficits for pores or small sunspot-type regions. The diverted heat flow was not totally blocked by the object. Because the sunspot-like object is magnetic and the convective flow closely surrounds it, some conversion between internal, kinetic, and magnetic energy is likely.

  17. Statistical analysis of the sunspot area and magnetic flux variations in 1996 2005 extracted from the Solar Feature Catalogue

    NASA Astrophysics Data System (ADS)

    Zharkov, S. I.; Zharkova, V. V.

    2006-01-01

    This research presents some statistical properties of sunspots and their magnetic fields extracted in from May 1996 to May 2005 from the SOHO/MDI full disk whitelight images and magnetograms for the searchable Solar Feature Catalogue (SFC) using the automated pattern recognition techniques. A comparison of the total sunspot areas on a given day from the SFC with the daily sunspot areas available from US AF SOON data for 2000-2004 reveal a very good correlation of the datasets with the correlation coefficient of ˜93%. The total sunspot areas in the Northern and Southern hemispheres measured from a single solar image and their cumulative areas during the whole cycle are shown to have a strong North-South asymmetry with the Northern hemisphere prevailing around and after the maximum while the Southern one Schatten taking over towards the coming solar minimum. The similar N-S asymmetry is observed in a total and resulting, or excess, magnetic fluxes. The former is found to follow closely the N-S asymmetry in the sunspot areas while the latter shows a very significant flux separation in the opposite hemispheres. The excess flux is negative in the Southern hemisphere and positive in the Northern one during a long period from 1997 until 2004. During the solar minimum in 1996, the signs of total excess fluxes in the hemispheres are changed to the opposite and a similar change appears in 2003-2004 towards the approaching solar minimum. Since the magnetic field in sunspots is those of the leading polarity, so the excess magnetic flux evolution is believed to show a change of the magnetic field leading polarity during the solar cycle minima, while the asymmetry of the total magnetic flux, possibly, reflects the asymmetry of a poloidal magnetic field, as it is predicted by the oscillatory dynamo models.

  18. 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.

  19. 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.

  20. Effects of the Scatter in Sunspot Group Tilt Angles on the Large-scale Magnetic Field at the Solar Surface

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

  1. Tropical daytime lower D-region dependence on sunspot number

    NASA Astrophysics Data System (ADS)

    Thomson, Neil R.; Rodger, Craig J.; Clilverd, Mark A.

    2012-10-01

    Observed phases and amplitudes of VLF radio signals propagating on (near) tropical all-sea paths, both short, ˜300 km, and long, ˜10 Mm, are used to find daytime parameter changes for the lowest edge of the (D-region of the) Earth's ionosphere as the solar cycle advanced from a very low sunspot number of ˜5 up to ˜60, in the period 2009-2011. The VLF phases, relative to GPS 1-s pulses, and amplitudes were measured ˜100 km from the transmitter, where the direct ground wave is very dominant, ˜300 km from the transmitter, near where the ionospherically reflected waves form a (modal) minimum with the ground wave, and ˜10 Mm away where the lowest order waveguide mode is fully dominant. Most of the signals came from the 19.8 kHz, 1-MW transmitter, NWC, North West Cape, Australia, propagating ENE, mainly over the sea, to the vicinity of Karratha and Dampier on the NW coast of Australia and then on to Kauai, Hawaii, ˜10.6 Mm from NWC. Observations from the 8.1-Mm path NPM (21.4 kHz, Hawaii) to Dunedin, NZ, are also used. The sunspot number increase from ˜5 to ˜60 was found to coincide with a decrease in the height, H‧, of the midday tropical ionosphere by 0.75 ± 0.25 km (from H‧ ≈ 70.5 km to H‧ ≈ 69.7 km) while the sharpness, β increased by 0.025 ± 0.01 km-1 (from β ≈ 0.47 km-1 to β ≈ 0.49 km-1) where H‧ and β are the traditional height and sharpness parameters used by Wait and by the U.S. Navy in their Earth-ionosphere VLF radio waveguide programs.

  2. Centennial variations in sunspot number, open solar flux and streamer belt width: 3. Modeling

    NASA Astrophysics Data System (ADS)

    Lockwood, M.; Owens, M. J.

    2014-07-01

    From the variation of near-Earth interplanetary conditions, reconstructed for the mid-19th century to the present day using historic geomagnetic activity observations, Lockwood and Owens (2014) have suggested that Earth remains within a broadened streamer belt during solar cycles when the Open Solar Flux (OSF) is low. From this they propose that the Earth was immersed in almost constant slow solar wind during the Maunder minimum (c. 1650-1710). In this paper, we extend continuity modeling of the OSF to predict the streamer belt width using both group sunspot numbers and corrected international sunspot numbers to quantify the emergence rate of new OSF. The results support the idea that the solar wind at Earth was persistently slow during the Maunder minimum because the streamer belt was broad.

  3. Solar grand and super-grand cycles derived with PCA from the solar background magnetic field

    NASA Astrophysics Data System (ADS)

    Zharkova, Valentina; Shepherd, Simon; Zharkov, Sergei; Popova, Elena

    2016-04-01

    We present principal components analysis (PCA) of temporal magnetic field variations over the solar cycles 21-24. These PCs reveal two main magnetic waves with close frequencies (covering 40% of data variance) travelling from the opposite hemispheres with an increasing phase shift. Extrapolation of these PCs through their summary curve backward for 2000 years reveals a number of ~350-year grand cycles and about 2000 super-grand cycles superimposed on 22 year-cycles with the features showing a remarkable resemblance to sunspot activity reported in the past. The summary curve calculated forward for the next millennium predicts further three grand cycles with the closest grand minimum occurring in the forthcoming cycles 25-27 when the two magnetic field waves have a phase shift of 11 years. We explore a role of other independent components derived with PCA and their expected effects on the resulting summary curve, or solar activity curve. We suggest that these grand and super-grand cycles can be produced by two dynamo waves generated in different layers with close frequencies whose interaction leads to beating effects that is discussed in the work by Popova et al (2016) presented here. This approach opens a new era in investigation and prediction of solar activity on long-term timescales.

  4. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    NASA Astrophysics Data System (ADS)

    Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi

    2015-09-01

    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.

  5. 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.

  6. Centennial variations in sunspot number, open solar flux, and streamer belt width: 2. Comparison with the geomagnetic data

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    We investigate the relationship between interdiurnal variation geomagnetic activity indices, IDV and IDV(1d), corrected sunspot number, RC , and the group sunspot number RG . RC uses corrections for both the "Waldmeier discontinuity," as derived in Paper 1, and the "Wolf discontinuity" revealed by Leussu et al. (2013). We show that the simple correlation of the geomagnetic indices with RCn or RGn masks a considerable solar cycle variation. Using IDV(1d) or IDV to predict or evaluate the sunspot numbers, the errors are almost halved by allowing for the fact that the relationship varies over the solar cycle. The results indicate that differences between RC and RG have a variety of causes and are highly unlikely to be attributable to errors in either RG alone, as has recently been assumed. Because it is not known if RC or RG is a better predictor of open flux emergence before 1874, a simple sunspot number composite is suggested which, like RG , enables modeling of the open solar flux for 1610 onward in Paper 3 but maintains the characteristics of RC .

  7. Short Dynamic Fibrils in Sunspot Chromospheres

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  8. Development of a Sunspot Tracking System

    NASA Technical Reports Server (NTRS)

    Taylor, Jaime R.

    1998-01-01

    Large solar flares produce a significant amount of energetic particles which pose a hazard for human activity in space. In the hope of understanding flare mechanisms and thus better predicting solar flares, NASA's Marshall Space Flight Center (MSFC) developed an experimental vector magnetograph (EXVM) polarimeter to measure the Sun's magnetic field. The EXVM will be used to perform ground-based solar observations and will provide a proof of concept for the design of a similar instrument for the Japanese Solar-B space mission. The EXVM typically operates for a period of several minutes. During this time there is image motion due to atmospheric fluctuation and telescope wind loading. To optimize the EXVM performance an image motion compensation device (sunspot tracker) is needed. The sunspot tracker consists of two parts, an image motion determination system and an image deflection system. For image motion determination a CCD or CID camera is used to digitize an image, than an algorithm is applied to determine the motion. This motion or error signal is sent to the image deflection system which moves the image back to its original location. Both of these systems are under development. Two algorithms are available for sunspot tracking which require the use of only one row and one column of image data. To implement these algorithms, two identical independent systems are being developed, one system for each axis of motion. Two CID cameras have been purchased; the data from each camera will be used to determine image motion for each direction. The error signal generated by the tracking algorithm will be sent to an image deflection system consisting of an actuator and a mirror constrained to move about one axis. Magnetostrictive actuators were chosen to move the mirror over piezoelectrics due to their larger driving force and larger range of motion. The actuator and mirror mounts are currently under development.

  9. 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.

  10. Sunspot Oscillations: A Review - (Invited Review)

    NASA Astrophysics Data System (ADS)

    Bogdan, T. J.

    2000-03-01

    The current state of our knowledge, and ignorance, of the nature of oscillations in sunspots is surveyed. An effort is made to summarize the robust aspects of both the observational and theoretical components of the subject in a coherent, and common, conceptual framework. Detailed discussions of the various controversial issues are avoided except in instances where new viewpoints are advanced. Instead, extensive references are made to the growing literature on the subject, and generous explanatory remarks are made to guide the reader who wishes to delve more deeply into the underpinnings of the subject matter.

  11. 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.

  12. Spatial structure of sunspot oscillations observed with SDO/AIA

    SciTech Connect

    Reznikova, V. E.; Shibasaki, K.

    2012-09-01

    The spatial structure of sunspot oscillations and its variation with frequency and height have been studied using data from SDO/AIA for two well-developed sunspots observed in 2010. Computation of potential magnetic fields together with line-of-sight and vector magnetograms from SDO/HMI allowed us to interpret discovered features of spatial structure. Namely, we have found that (1) expansion of the magnetic field lines above the sunspot causes a gradual broadening of the area occupied by the 3 minute oscillations with height, and (2) variation of magnetic field inclination across the sunspot causes a decrease in the pulsation frequency with distance from the center of the umbra. We have shown that the transformation from 3 minute umbral oscillations to 5 minute penumbral waves can be explained by variation of the acoustic cutoff frequency across the sunspot.

  13. The properties of long-term sunspot oscillations

    NASA Astrophysics Data System (ADS)

    Nagovitsyn, Yu. A.; Rybak, A. L.

    2014-05-01

    It is shown that neglecting the motion of sunspots in the plane of the sky in pixels of SOHO MDI magnetograms obtained for the vertical direction results in false periods of 700-1300 min in the long-term oscillations of the magnetic fields of sunspots observed near the central meridian (the Y artefact). The oscillation mode proposed by Efremov, Parfinenko, and Solov'ev in 2012 to be the lowest-frequency sunspot mode is an artefact. A proposed technique for monitoring this artefact using wavelet transforms can be used to study oscillation periods in the range 15 min < T < 500 min. The observational dependence of the oscillation frequency of the sunspot magnetic field on the field strength is constructed using observations of 45 sunspots. This dependence shows a multimode behavior that is consistent with earlier ground observations. One interpretation of this dependence based on the existence of four geometrical oscillation modes detected earlier is proposed.

  14. Sunspotter: Using Citizen Science to Determine the Complexity of Sunspots

    NASA Astrophysics Data System (ADS)

    Higgins, Paul A.; Perez-Suarez, David; Parrish, Michael; O'Callaghan, David; Leka, K D.; Barnes, Graham; Roche, Joseph; Gallagher, Peter T

    2014-06-01

    It is well known that sunspot groups with large, complex magnetic field configurations and strong, sheared polarity separation lines produce the largest flares. While methods for determining certain physical properties, such as total magnetic flux and polarity-separation-line length have been successfully developed for characterizing sunspot groups, a reliable automated method for determining sunspot complexity has never been developed. Since complexity can only be measured in a relative sense, we have used crowd-sourcing methods to allow human observers to compare the complexity of pairs of sunspot groups. This allows a large dataset to be ranked in terms of complexity. Sunspotter.org uses the Zooniverse platform and allows the general public to contribute comparisons using a web-browser interface. The results of this project will help to establish the true relationship between sunspot group complexity and flares, which has been discussed in the solar physics community for many decades.

  15. Is a sudden increase of irregularity of sunspot numbers a precursor of a return to low solar activity?

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We have recently introduced an irregularity index λ for daily sunspot numbers International Sunspot Number (ISSN), derived from the well-known Lyapunov exponent, that attempts to reflect irregularities in the chaotic process of solar activity. Like the Lyapunov exponent, the irregularity index is computed from the data for different embedding dimensions m (2-32). When m = 2, λ maxima match ISSN maxima of the Schwabe cycle, whereas when m = 3, λ maxima occur at ISSN minima. The patterns of λ as a function of time remain similar from m = 4 to 16: the dynamics of λ change between 1915 and 1935, separating two regimes, one from 1850 to 1915 and the other from 1935 to 2005, in which λ retains a similar structure. A sharp peak occurs at the time of the ISSN minimum between cycles 23 and 24, possibly a precursor of unusual cycle 24 and maybe a new regime change; λ is significantly smaller during the ascending and descending phases of solar cycles. Differences in values of the irregularity index observed for different cycles reflect differences in correlations in sunspot series at a scale much less than the 4 year sliding window used in computing them; the lifetime of sunspots provides a source of correlation at that time scale. The burst of short-term irregularity evidenced by the strong λ peak at the minimum of cycles 23 and 24 would reflect a decrease in correlation at the time scale of several days rather than a change in the shape of the cycle.

  16. 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.

  17. 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.

  18. 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.

  19. Pathways Linking Perceived Athletic Competence and Parental Support at Age 9 Years to Girls' Physical Activity at Age 11 Years

    ERIC Educational Resources Information Center

    Davison, Kirsten Krahnstoever; Downs, Danielle Symons; Birch, Leann L.

    2006-01-01

    Girls' perceived athletic competence and parental support of physical activity across the ages of 9 to 11 years were examined as predictors of girls' physical activity at age 11 years. Participants were 174 girls and their mothers and fathers who completed questionnaires when the girls were ages 9 and 11 years. Two alternative temporal pathways…

  20. 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.

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. Dermatitis rhabditidosa in an 11-year-old girl: a new cutaneous parasitic disease of man.

    PubMed

    Pasyk, K

    1978-01-01

    Rhabditiform larvae of Rhabditis (Pelodera) strongyloides caused pruritic lesions in an 11-year-old girl, and persisted for 2 1/2 months. Larvae were found in skin scrapings from the child and in the family dog's hair. PMID:564202

  9. Meaning-Making with Colour in Multimodal Texts: An 11-Year-Old Student's Purposeful "Doing"

    ERIC Educational Resources Information Center

    Pantaleo, Sylvia

    2012-01-01

    Colour, a visual element of art and design, is a semiotic mode that is used strategically by sign-makers to communicate meaning. Understanding the meaning-making potential of colour can enhance students' understanding, appreciation, interpretation and composition of multimodal texts. This article features a case study of Anya, an 11-year-old…

  10. The Relationship among 100% Juice Consumption, Nutrient Intake, and Weight of Children 2-11 Years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inconsistent research findings have led to continued debate over the potential associations between 100% juice consumption (JC), nutrient intake,and weight in children. The objective is to investigate the associations between JC, nutrient intake, and weight in children. Children 2 to 11 years of a...

  11. 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...

  12. Losing Our Way? The Downward Path for Outdoor Learning for Children Aged 2-11 Years

    ERIC Educational Resources Information Center

    Waite, Sue

    2010-01-01

    This paper draws on three related empirical studies in the South West of England: a survey of outdoor experiential learning opportunities, examining attitudes, practice and aspirations of practitioners and children in educational and care settings for children between 2-11 years within a rural county; a follow-up series of five case studies; and…

  13. 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.

  14. One Possible Reason for Double-Peaked Maxima in Solar Cycles: Is a Second Maximum of Solar Cycle 24 Expected?

    NASA Astrophysics Data System (ADS)

    Kilcik, A.; Ozguc, A.

    2014-04-01

    We investigate solar activity by focusing on double maxima in solar cycles and try to estimate the shape of the current solar cycle (Cycle 24) during its maximum. We analyzed data for Solar Cycle 24 by using Learmonth Solar Observatory sunspot-group data collected since 2008. All sunspot groups (SGs) recorded during this time interval were separated into two groups: The first group includes small SGs [A, B, C, and H classes according to the Zurich classification], the second group consists of large SGs [D, E, and F]. We then calculated how many small and large sunspot groups occurred, their sunspot numbers [SSN], and the Zurich numbers [ Rz] from their daily mean numbers as observed on the solar disk during a given month. We found that the temporal variations for these three different separations behave similarly. We also analyzed the general shape of solar cycles from Cycle 1 to 23 by using monthly International Sunspot Number [ISSN] data and found that the durations of maxima were about 2.9 years. Finally, we used the ascending time and SSN relationship and found that the maximum of Solar Cycle 24 is expected to occur later than 2011. Thus, we conclude that i) one possible reason for a double maximum in solar cycles is the different behavior of large and small sunspot groups, and ii) a double maximum is expected for Solar Cycle 24.

  15. Comparison of New and Old Sunspot Number Time Series

    NASA Astrophysics Data System (ADS)

    Cliver, Edward W.; Clette, Frédéric; Lefévre, Laure; Svalgaard, Leif

    2016-05-01

    As a result of the Sunspot Number Workshops, five new sunspot series have recently been proposed: a revision of the original Wolf or international sunspot number (Lockwood et al., 2014), a backbone-based group sunspot number (Svalgaard and Schatten, 2016), a revised group number series that employs active day fractions (Usoskin et al., 2016), a provisional group sunspot number series (Cliver and Ling, 2016) that removes flaws in the normalization scheme for the original group sunspot number (Hoyt and Schatten,1998), and a revised Wolf or international number (termed SN) published on the SILSO website as a replacement for the original Wolf number (Clette and Lefèvre, 2016; thttp://www.sidc.be/silso/datafiles). Despite quite different construction methods, the five new series agree reasonably well after about 1900. From 1750 to ~1875, however, the Lockwood et al. and Usoskin et al. time series are lower than the other three series. Analysis of the Hoyt and Schatten normalization factors used to scale secondary observers to their Royal Greenwich Observatory primary observer reveals a significant inhomogeneity spanning the divergence in ~1885 of the group number from the original Wolf number. 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.

  16. On the maintenance of sunspots - an ion hurricane mechanism

    NASA Astrophysics Data System (ADS)

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

    1985-12-01

    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.

  17. Helioseismology of sunspots: defocusing, folding, and healing of wavefronts

    NASA Astrophysics Data System (ADS)

    Liang, Z.-C.; Gizon, L.; Schunker, H.; Philippe, T.

    2013-10-01

    We observe and characterize the scattering of acoustic wave packets by a sunspot in a regime where the wavelength is comparable to the size of the sunspot. Spatial maps of wave travel times and amplitudes are measured from the cross-covariance function of the random wave field observed by SOHO/MDI around the sunspot in active region NOAO 9787. We consider separately incoming plane wave packets consisting of f modes and p modes with radial orders up to four. Observations show that the travel-time perturbations diminish with distance far away from the sunspot - a finite-wavelength phenomenon known as wavefront healing in scattering theory. Observations also show a reduction of the amplitude of the waves after their passage through the sunspot. We suggest that a significant fraction of this amplitude reduction is due to the defocusing of wave energy by the fast wave-speed perturbation introduced by the sunspot. This "geometrical attenuation" will contribute to the wave amplitude reduction in addition to the physical absorption of waves by sunspots. We also observe an enhancement of wave amplitude away from the central path: diffracted rays intersect with unperturbed rays (caustics) and wavefronts fold and triplicate. Wave amplitude measurements in time-distance helioseismology provide independent information that can be used in concert with travel-time measurements.

  18. 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.

  19. 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.

  20. Photometric measurements of solar irradiance variations due to sunspots

    SciTech Connect

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

    1989-08-01

    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. 23 refs.

  1. Does age at first treatment episode make a difference in outcomes over 11 years?

    PubMed

    Chi, Felicia W; Weisner, Constance; Grella, Christine E; Hser, Yih-Ing; Moore, Charles; Mertens, Jennifer

    2014-04-01

    This study examines the associations between age at first substance use treatment entry and trajectory of outcomes over 11 years. We found significant differences in individual and treatment characteristics between adult intakes first treated during young adulthood (25 years or younger) and those first treated at an older age. Compared to their first treated older age counterparts matched on demographics and dependence type, those who entered first treatment during young adulthood had on average an earlier onset for substance use but a shorter duration between first substance use and first treatment entry; they also had worse alcohol and other drug outcomes 11 years post treatment entry. While subsequent substance use treatment and 12-step meeting attendance are important for both age groups in maintaining positive outcomes, relationships varied by age group. Findings underline the importance of different continuing care management strategies for those entering first treatment at different developmental stages. PMID:24462221

  2. Stochastic Description of the High-frequency Content of Daily Sunspots and Evidence for Regime Changes

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

  3. 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.

  4. Republication of: Radial Movement in Sunspots

    NASA Astrophysics Data System (ADS)

    Hasan, S. S.

    Displacements of the lines of hydrogen and calcium in the neighbourhood of sunspots, indicating violent motions in the line of sight, is a common characteristic of spot disturbances. Such phenomena are frequently observed during periods of active change in spot development, or during the genesis of a spot. These line-shifts rarely affect the spectra of other elements than those of the higher chromospheres. In very violent outbursts, in addition to the hydrogen and calcium lines, those of He, Mg, Na, and some of the enhanced displacements may be either an increase or a decrease of wave-length, and may amount to several Ångström units, indicating movements of approach or recession of several hundred kilometers per second. These movements are seldom maintained for more than a few minutes at a time, and are usually to be found in the immediate neighbourhood of sports, rarely within the umbral area.

  5. SUPERSONIC DOWNFLOWS IN A SUNSPOT LIGHT BRIDGE

    SciTech Connect

    Louis, Rohan E.; Mathew, Shibu K.; Venkatakrishnan, P.; Bellot Rubio, Luis R.

    2009-10-10

    We report the discovery of supersonic downflows in a sunspot light bridge using measurements taken with the spectropolarimeter onboard the Hinode satellite. The downflows occur in small patches close to regions where the vector magnetic field changes orientation rapidly, and are associated with anomalous circular polarization profiles. An inversion of the observed Stokes spectra reveals velocities of up to 10 km s{sup -1}, making them the strongest photospheric flows ever measured in light bridges. Some (but not all) of the downflowing patches are cospatial and cotemporal with brightness enhancements in chromospheric Ca II H filtergrams. We suggest that these flows are due to magnetic reconnection in the upper photosphere/lower chromosphere, although other mechanisms cannot be ruled out.

  6. 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.

  7. [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. PMID:22740016

  8. Adult onset asynchronous multifocal eosinophilic granuloma of bone: an 11-year follow-up

    PubMed Central

    Dallaudière, Benjamin; Kerger, Joseph; Malghem, Jacques; Galant, Christine

    2015-01-01

    Multifocal eosinophilic granuloma (EG) is a rare observation within the spectrum of histiocytosis X, generally described in children. We report the case of a 33-year-old man with multifocal EG showing an asynchronous evolution of bone lesions during a follow-up of 11 years. We also present the therapeutic approach chosen for this patient and the repeated magnetic resonance imaging (MRI) examinations used to monitor the disease with a final favorable outcome. PMID:25793108

  9. 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.

  10. 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.

  11. Sunspot bright rings and the thermal diffusivity of solar convection

    NASA Technical Reports Server (NTRS)

    Duvall, T., Jr.; Fowler, L. A.; Foukal, P.

    1983-01-01

    Raster-scan observations of 10 sunspots, made in 1980 and 1981 with the 512-channel diode array and vacuum telescope at the Kitt Peak National Observatory, are reported. Data from several 10-min scans of 0.25-A passbands of clean continuum were summed to give an rms noise level of 0.25 percent, corrected by applying a limb-darkening curve, and analyzed to determine the average intensity for each of eight segments of a series of concentric rings around each sunspot. Faculae and pores were identified and discarded in constructing radial intensity profiles. Marginally significant bright symmetric rings (peak amplitude 0.1-0.3 percent) not attributable to residual facular signal or instrumental effects were observed around 6 of 10 sunspots. No evidence of more intense bright rings was found. These findings are discussed in terms of thermal-diffusion models proposed to explain the fate of the radiative flux blocked by sunspots.

  12. Lithium abundances in sunspots from observations made in 2014

    NASA Astrophysics Data System (ADS)

    Baranovskii, E. A.; Tarashchuk, V. P.

    2016-08-01

    Spectra of sunspots in the regions of the Li I 6708 Å line and certain Fe I and Ca I lines are presented. The observations wee carried out in August 2014 using a CCD array mounted at the BST-2 telescope of the Crimean Astrophysical Observatory. Sunspot models based on the observed Fe I and Ca I line profiles have been computed, and used together with the observed Li I 6708 Å profiles to determine the lithium abundances. The mean lithium abundance for the sunspots observed on August 26, 2014 is log A(Li) = 1.2 (on a scale for which log A(H) = 12.0). Sunspot spectra obtained on October 8, 2011 were also analyzed, yielding log A(Li) = 1.02.

  13. Modelling of the Flare Observed Above Sunspot Penumbra

    NASA Astrophysics Data System (ADS)

    Berlicki, A.; Heinzel, P.; Schmieder, B.; Li, H.

    2008-09-01

    The solar flaring atmosphere above sunspot observed during the event on October 20, 2003 was analysed. Many flaring structures were visible in projection onto the sunspot penumbra. We analysed the H? and Ca II line profiles emitted by the ribbons partially overlapping the sunspots. These observations were performed with the Multi-channel Infrared Solar Spectrograph (MISS) at Purple Mountain Observatory (PMO, China). In the sunspot penumbra, the line intensity in far wings is lower than in a typical quiet-Sun profile but in the line centre the intensity of H? and Ca II lines is typical for flares. Using 1D approximation we tried to find the vertical structure of the flare observed above sunspot penumbra using the observations of these chromospheric line profiles. NLTE radiative transfer techniques allowed us to model the atmosphere of flaring structures and fit both the synthetic H? and Ca II line profiles to the observed ones. We have determined semiempirical models of the flaring structure observed above sunspots. In our analysis we showed that the flare emission observed within sunspot penumbra comes from geometrically thin loop-like structures located above the fibrils of the penumbra. The structure of the penumbra located below the flare is almost not affected by the flare. The flare emission in chromospheric lines comes not from the upper chromosphere but from the structures located higher in the corona. Therefore, we performed two-component modelling which well reproduce the flare emission above sunspot penumbra. In our model of the flaring layer we included the transition region which is necessary to obtain agreement between the observed and calculated line profiles.

  14. 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

  15. 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).

  16. Numerical models of sunspot formation and fine structure.

    PubMed

    Rempel, Matthias

    2012-07-13

    Sunspots are central to our understanding of solar (and stellar) magnetism in many respects. On the large scale, they link the magnetic field observable in the photosphere to the dynamo processes operating in the solar interior. Properly interpreting the constraints that sunspots impose on the dynamo process requires a detailed understanding of the processes involved in their formation, dynamical evolution and decay. On the small scale, they give an insight into how convective energy transport interacts with the magnetic field over a wide range of field strengths and inclination angles, leading to sunspot fine structure observed in the form of umbral dots and penumbral filaments. Over the past decade, substantial progress has been made on both observational and theoretical sides. Advanced ground- and space-based observations have resolved, for the first time, the details of umbral dots and penumbral filaments and discovered similarities in their substructures. Numerical models have advanced to the degree that simulations of entire sunspots with sufficient resolution to resolve sunspot fine structure are feasible. A combination of improved helioseismic inversion techniques with seismic forward modelling provides new views on the subsurface structure of sunspots. In this review, we summarize recent progress, with particular focus on numerical modelling. PMID:22665895

  17. 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.

  18. 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.

  19. 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.

  20. The solar cycle - A central-source wave theory

    NASA Technical Reports Server (NTRS)

    Bracewell, R. N.

    1989-01-01

    Studies stimulated by the interpretation of the Elatina formation in South Australia as a fossil record of solar activity have led to discoveries of previously unnoticed features of the sunspot cycle record and to a theory of origin of the sunspot cycle that postulates a solar core in torsional motion and a magnetomechanical wave that couples to the photosphere. The considerations supporting the solar interpretation of the Elatina formation are gathered together.

  1. 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

  2. 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

  3. 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

  4. 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

  5. Toxic interaction between fluvoxamine and sustained release theophylline in an 11-year-old boy.

    PubMed

    Sperber, A D

    1991-01-01

    An 11-year-old boy with asthma had been receiving a controlled release theophylline preparation. He was prescribed fluvoxamine for a depressive disorder and within a week complained of severe headaches, tiredness and vomiting. His serum theophylline concentration had increased from 14.2 mg/L (shortly before fluvoxamine was started) to 27.4 mg/L. Fluvoxamine was withdrawn and theophylline concentrations decreased. Clomipramine was substituted for fluvoxamine with no further problems, and a later theophylline concentration was 13.7 mg/L. Competitive inhibition of hepatic microsomal enzymes by fluvoxamine may have been responsible for the elevated theophylline concentrations and toxicity observed in this case. PMID:1793525

  6. Extrapyramidal side-effects of low-dose aripiprazole in an 11-year-old child.

    PubMed

    Mohapatra, Satyakam

    2016-01-01

    Partial agonism of D2 and 5-HT1A receptors accounts for the low incidence of extrapyramidal side-effects of aripiprazole. Extrapyramidal symptoms (EPS) during treatment with therapeutical doses of aripiprazole have been reported in adults and children. To the best of our knowledge, no cases of EPS with low doses (5 mg) have been reported until now. In this article, we present an 11-year-old child who developed EPS on low doses (5 mg) aripiprazole. This case emphasizes the need for careful surveillance for the development of EPS in patients treated even with low doses of aripiprazole. PMID:26933364

  7. 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. PMID:24911856

  8. Giant appendix or an appendiceal mucocele? Case report of an 11-year-old child

    PubMed Central

    Nad, Marta; Kiraly, Adrienn; Bali, Ottilia; Rashed, Adel; Vizsy, Laszlo

    2014-01-01

    We present an 11-year-old male child with an enormous appendix that was regarded as an appendiceal mucocele. The disorder is very rare and usually appears in middle aged patients. It is a clinical diagnosis. It could cause a variety of symptoms, especially, acute appendicitis and unidentified lesion in the right iliac fossa. According to the reasons, it could be just a curiosity without any relevancy or the sign of a malignant lesion with bad prognostic factors. The histopathological findings prove the origin. PMID:25598994

  9. Extrapyramidal side-effects of low-dose aripiprazole in an 11-year-old child

    PubMed Central

    Mohapatra, Satyakam

    2016-01-01

    Partial agonism of D2 and 5-HT1A receptors accounts for the low incidence of extrapyramidal side-effects of aripiprazole. Extrapyramidal symptoms (EPS) during treatment with therapeutical doses of aripiprazole have been reported in adults and children. To the best of our knowledge, no cases of EPS with low doses (5 mg) have been reported until now. In this article, we present an 11-year-old child who developed EPS on low doses (5 mg) aripiprazole. This case emphasizes the need for careful surveillance for the development of EPS in patients treated even with low doses of aripiprazole. PMID:26933364

  10. Sacrococcygeal fetiform teratoma altman type 1: a rare case report in a 11 year old girl.

    PubMed

    Sood, Neelam; Kamboj, Meenakshi; Chaabra, Maninder

    2013-06-01

    Fetiform teratoma (homunculus) is a rare but distinct entity, characterized by presence of more organoid differentiation than the classical teratoma but not enough to classify as fetus-in-fetu. Presence of rudimentary limbs in presence/absence of axial skeleton is often reported as an important differentiating feature. Sacrococcygeal location has been reported in a few case reports but in neonates only. This is a rare case of sacrococcygeal fetiform teratoma (Altman type 1) in an 11-year-old girl presenting as a gluteal mass. PMID:24426616

  11. 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.

  12. 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.

  13. A Study of Heliospheric Modulation and Periodicities of Galactic Cosmic Rays During Cycle 24

    NASA Astrophysics Data System (ADS)

    Chowdhury, Partha; Kudela, K.; Moon, Y.-J.

    2016-02-01

    Galactic cosmic rays (GCRs) are energetic, charged particles coming from outside the solar system. These particles encounter an outward-moving turbulent solar wind with cyclic magnetic-field fluctuations when entering the heliosphere. This causes convection and diffusion in the heliosphere. The GCR counts detected by the ground-based neutron-monitor stations show intensity changes with a fluctuation of ˜ 11 years and are anti-correlated with the sunspot numbers with some time lags. GCRs experience various types of modulation from different solar activity features and are important components of space weather. The previous solar cycle, Cycle 23, has shown anomalous behavior with a prolonged deep minimum, which was characterized by a record-setting high Galactic cosmic-ray flux observed at Earth. Solar Cycle 24 started much later than expected and progressed sluggishly toward its maxima. In this paper, we study the heliospheric modulation and intermediate-term periodicities of GCRs during the ascending phase of Cycle 24. We utilize simultaneous solar, interplanetary plasma, magnetic field, and geomagnetic activity data including the tilt angle of the heliospheric current sheet, and we study their relation with GCRs. The wavelet power spectrum of GCRs exhibits the presence of a variety of prominent short- and mid-term periodicities including the well-known Rieger and quasi-biennial periodicities. Possible explanations of the observed results are discussed in the light of numerical models.

  14. 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.

  15. Solar Flare Probability depending on Sunspot Characteristics and Their Changes

    NASA Astrophysics Data System (ADS)

    Lee, J.; Hong, S.; Kim, J.; Kim, Y.; Lee, J.; Moon, Y.; Lee, D.

    2012-12-01

    Solar flare prediction has been at the core of space weather research and a number of different approaches have been developed since THEO (McIntosh, 1990) system was introduced. However, many of space weather operation centers, i.e. International Space Environment Service's Regional Warning Centers, still rely on traditional flare prediction methods like THEO. THEO uses the McIntosh classification as the knowledge base for flare prediction and also, rules of thumb are incorporated by a human forecaster, including spot growth, magnetic topology inferred from sunspot structure and previous flare activity. The method is apparently somewhat subjective, because the forecast decision depends on the expertise of an operator and it has not been evaluated statistically. In this study, we have investigated solar flare probability depending on several sunspot characteristics (McIntosh classification, Mt. Wilson magnetic classification, sunspot area and previous flare activity) and their changes for the past three days. For this, we used NOAA sunspot and flare catalog from August 1996 to February 2011. A new index, WFP(Weighted Flare Probability), which includes solar flare strength and its historical probability, is introduced to quantify the effective contribution of flare activity. We found several interesting results as follows. First, WFP index increases not only when the sunspot magnetic complexity increases but also when the magnetic complexity decreases with almost the same proportion. Second, the index also increases for both cases of sunspot area increase and decrease. This result might be the evidence that the change (flux emergence or flux cancelation) of magnetic flux may trigger a flare since sunspot area can be a good proxy of magnetic flux. Third, active regions having significant flare activity history are much more active than those without. We are applying the multi-dimensional regression method to these data and automating the process of THEO. We have a

  16. Study of Ionospheric Indexes T and MF2 related to R12 for Solar Cycles 19-21

    NASA Astrophysics Data System (ADS)

    Villanueva, Lucia

    2013-04-01

    Modern worldwide communications are mainly based on satellite systems, remote communication networks, and advanced technologies. The most important space weather "meteorological" events produce negative effects on signal transmissions. Magnetic storm conditions that follow coronal mass ejections are particularly of great importance for radio communication at HF frequencies (3-30 MHz range), because the Ionization increase (or decrease), significantly over (or below), the Average Values. Nowadays new technologies make possible to establish Geophysical Observatories and monitor the sun almost in real time giving information about geomagnetic indices. Space Weather programs have interesting software predictions of foF2 producing maps and plots, every some minutes. The Average Values of the ionospheric parameters mainly depend on the position, hour, season and the phase of the 11-year cycle of the solar activity. Around 1990´s several ionospheric indexes were suggested to better predict the state of the foF2 monthly media, as: IF2, G, T and MF2, based on foF2 data from different latitude ionospheric observatories. They really show better seasonal changes than monthly solar indexes of solar flux F10.7 or the international sunspot numbers Ri. The main purpose of this paper is to present an analogic model for the ionospheric index MF2, to establish the average long term predictions of this index. Changes of phase from one cycle to the other of one component of the model is found to fit the data. The usefulness of this model could be the prediction of the ionospheric normal conditions for one entire solar cycle having just the prediction of the maximum of the next smooth sunspot number R12. In this presentation, comparisons of the Australian T index and and the Mikhailov MF2 index show an hysteresis variation with the solar monthly index Ri, such dependence is quite well represented by a polynomial fit of degree 6 for rising and decaying fases for solar cycles 19, 20 and

  17. 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. PMID:25972393

  18. 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. PMID:25365262

  19. 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. PMID:26954467

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

    PubMed Central

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

    2015-01-01

    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. PMID:25972393

  1. 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.

  2. Solar B/Hinode Image of Sunspot

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Hinode (Sunrise), formerly known as Solar-B before reaching orbit, was launched from the Uchinoura Space Center in Japan on September 23, 2006. Hinode was designed to probe into the Sun's magnetic field to better understand the origin of solar disturbances which interfere with satellite communications, electrical power transmission grids, and the safety of astronauts traveling beyond the Earth's magnetic field. Hinode is circling Earth in a polar orbit that places the instruments in continuous sunlight for nine months each year and allows data dumps to a high latitude European Space Agency (ESA) ground station every orbit. NASA and other science teams will support instrument operations and data collection from the spacecraft's operation center at the Japanese Aerospace Exploration Agency's (JAXA's) Institute of Space and Aeronautical Science facility located in Tokyo. The Hinode spacecraft is a collaboration among space agencies of Japan, the United States, the United Kingdom, and Europe. The Marshall Space Flight Center (MSFC) managed development of three instruments comprising the spacecraft; the Solar Optical Telescope (SOT); the X-Ray Telescope (XRT); and the Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS). This image of a sunspot, taken by Hinode, is a prime example of what the spacecraft can offer.

  3. Solar Cycle 23: An Anomalous Cycle?

    NASA Astrophysics Data System (ADS)

    de Toma, G.; White, O. R.; Chapman, G. A.; Walton, S. R.; Preminger, D. G.; Cookson, A. M.

    2004-05-01

    We discuss the importance of solar cycle 23 as a magnetically simpler cycle and a variant from recent cycles. We see a significant decrease in sunspot activity in cycle 23 relative to cycle 22, but the strength of the total solar irradiance (TSI) cycle did not change significantly. The latest SOHO/VIRGO TSI time series is analyzed using new solar variability measures obtained from full-disk solar images made at the San Fernando Observatory and the MgII 280nm index. The TSI record for the period 1986 to the present is reproduced within about 130ppm RMS using only two indices representing photospheric and chromospheric sources of variability due to magnetic regions. This is in spite of the difference in magnetic activity between the two cycles. Our results show the continuing improvement in TSI measurements and surrogates containing information necessary to account for irradiance variability.

  4. 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

  5. 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.

  6. 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.

  7. Postintubation tracheal stenosis in an 11-year-old boy: a surgical and anaesthetic challenge.

    PubMed

    Aguilera, I M; Walker, R W M; Dearlove, O R

    2002-10-01

    We present a case of postintubation tracheal stenosis in an 11-year-old boy occurring after a relatively short period of intubation. He had been intubated and ventilated in a paediatric intensive care unit after a road traffic accident. Clinical symptoms manifested by oxygen desaturation and wheeziness, finally leading to deterioration of the level of consciousness, occurred a few hours after the first attempt at extubation after 48 h requiring reintubation. Endoscopic examination performed a few weeks later revealed a tracheal stenosis. Consequently, he underwent an initial period of conservative treatment consisting of balloon dilatation and intralesional injection of steroids, followed by a tracheal resection and reconstruction. The anaesthetic management of patients with tracheal stenosis presenting for laryngo-tracheobronchoscopy and balloon dilatation is discussed. PMID:12472713

  8. 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.

  9. Acute Ataxia in Childhood: 11-Year Experience at a Major Pediatric Neurology Referral Center.

    PubMed

    Thakkar, Kavita; Maricich, Stephen M; Alper, Gulay

    2016-08-01

    We categorized the causes of acute ataxia in the pediatric population-referred to the Division of Neurology-at a large, urban pediatric medical center. Of the 120 cases identified over the past 11 years, post-infectious cerebellar ataxia was the most commonly diagnosed (59%), followed by drug intoxication, opsoclonus-myoclonus ataxia syndrome, episodic ataxia, acute cerebellitis, cerebellar stroke, ADEM, meningitis, cerebral vein thrombosis, Leigh's disease, Miller-Fisher syndrome, and concussion. Among the patients with post-infectious cerebellar ataxia, 85% were 1-6 years old and all had a history of antecedent viral illness. CSF pleocytosis was present in 40% of patients; all had normal brain MRIs. The majority (91%) recovered within 30 days. We conclude that post-infectious cerebellar ataxia remains the most common cause of acute ataxia in childhood and that it carries a good prognosis. We also differentiate acute post-infectious cerebellar ataxia from other causes with similar presentations. PMID:27071467

  10. An 11-year-old boy with pharyngitis and cough: Lemierre syndrome

    PubMed Central

    Mação, Patricia; Cancelinha, Candida; Lopes, Paulo; Rodrigues, Fernanda

    2013-01-01

    The authors present the case of an 11-year-old boy with pharyngitis, treated with amoxicillin, that worsened on day 7, with cough, high fever and refusal to eat. Lethargy and respiratory distress were noted. Based on radiographic findings of bilateral infiltrates he was diagnosed with pneumonia and started on intravenous ampicillin and erythromycin. Two days later he complained of right-sided neck pain and a palpable mass was identified. An ultrasound showed partial thrombosis of the right internal jugular vein and a lung CT scan revealed multiple septic embolic lesions. Lemierre syndrome was diagnosed, antibiotic treatment adjusted and anticoagulation started. A neck CT-scan showed a large parapharyngeal abscess. His clinical condition improved gradually and after 3 weeks of intravenous antibiotics he was discharged home on oral treatment. This case illustrates the importance of diagnosing Lemierre syndrome in the presence of pharyngitis with localised neck pain and respiratory distress, to prevent potentially fatal complications. PMID:23616317

  11. Performance as a function of shooting style in basketball players under 11 years of age.

    PubMed

    Arias, José L

    2012-04-01

    Shooting style in basketball refers to the height adopted by a player in holding the ball, specifically the height of the hand and the ball with regard to the line of sight before the final extension of the elbow during a shot. The literature differentiates between a high and a low style. This study analyzed shooting frequency in young boys as a function of style and which shooting style had the highest accuracy and success in real games. Participants were 81 boys from eight basketball teams, aged 9-11 years. The sample consisted of 5,740 standard shots in 56 games. The design was nomotethic, follow-up, and multidimensional. The results indicated that low style predominated over the high style, although overall accuracy and efficacy were better using the high style. Various strategies and practical considerations are suggested for teachers and coaches to focus on teaching the high style. PMID:22755449

  12. 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. PMID:27226096

  13. An 11-year-old boy with Plasmodium falciparum malaria and dengue co-infection.

    PubMed

    Issaranggoon na ayuthaya, Satja; Wangjirapan, Anchalee; Oberdorfer, Peninnah

    2014-01-01

    Malaria and dengue fever are major mosquito-borne public health problems in tropical countries. The authors report a malaria and dengue co-infection in an 11-year-old boy who presented with sustained fever for 10 days. The physical examination revealed a flushed face, injected conjunctivae and left submandibular lymphadenopathy. His peripheral blood smear showed few ring-form trophozoites of Plasmodium falciparum. His blood tests were positive for dengue NS-1 antigen and IgM antibody, and negative for IgG antibody. After the initiation of antimalarial treatment with artesunate and mefloquine, his clinical condition gradually improved. However, he still had low-grade fever that persisted for 6 days. Finally, he recovered well without fluid leakage, shock or severe bleeding. This case report emphasises that early recognition and concomitant treatment of malaria and dengue co-infection in endemic areas can improve clinical outcome and prevent serious complications. PMID:24692379

  14. Pulmonary veno-occlusive disease in an 11-year-old girl: diagnostic pitfalls.

    PubMed

    Kano, Gen; Nakamura, Keiko; Sakamoto, Izumi

    2014-02-01

    Pulmonary veno-occlusive disease (PVOD) is a rare chronic lung disease that is difficult to diagnose due to non-specific clinical findings. Little is known about the pathogenesis of PVOD. Reported herein is the case of an 11-year-old girl who initially presented with 'bat-wing' shadows on chest radiography. This finding, coupled with prominent hemosiderosis in bronchoalveolar lavage fluid, initially led to a misdiagnosis of idiopathic pulmonary hemosiderosis. Oral prednisolone dramatically improved signs and symptoms initially, but her condition then gradually deteriorated during maintenance therapy with corticosteroids and other immunosuppressants. PVOD was suspected but not confirmed owing to a lack of hallmark radiographic findings and contraindications for lung biopsy. Three years later, while arranging for lung transplantation, the patient experienced sudden onset of fatal massive pulmonary edema. PVOD was confirmed at autopsy. This case provides insights regarding an unfamiliar presentation of PVOD and may help physicians to avoid diagnostic pitfalls. PMID:24548200

  15. 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. PMID:16597767

  16. 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

  17. 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.

  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. ANALYSIS OF A FRAGMENTING SUNSPOT USING HINODE OBSERVATIONS

    SciTech Connect

    Louis, Rohan E.; Mathew, Shibu K.; Raja Bayanna, A.; Venkatakrishnan, P.; Ravindra, B.; Bellot Rubio, Luis R.

    2012-08-10

    We employ high-resolution filtergrams and polarimetric measurements from Hinode to follow the evolution of a sunspot for eight days starting on 2007 June 28. The imaging data were corrected for intensity gradients, projection effects, and instrumental stray light prior to the analysis. The observations show the formation of a light bridge at one corner of the sunspot by a slow intrusion of neighboring penumbral filaments. This divided the umbra into two individual umbral cores. During the light bridge formation, there was a steep increase in its intensity from 0.28 to 0.7 I{sub QS} in nearly 4 hr, followed by a gradual increase to quiet-Sun (QS) values in 13 hr. This increase in intensity was accompanied by a large reduction in the field strength from 1800 G to 300 G. The smaller umbral core gradually broke away from the parent sunspot nearly two days after the formation of the light bridge, rendering the parent spot without a penumbra at the location of fragmentation. The penumbra in the fragment disappeared first within 34 hr, followed by the fragment whose area decayed exponentially with a time constant of 22 hr. In comparison, the parent sunspot area followed a linear decay rate of 0.94 Mm{sup 2} hr{sup -1}. The depleted penumbra in the parent sunspot regenerated when the inclination of the magnetic field at the penumbra-QS boundary became within 40 Degree-Sign from being completely horizontal and this occurred near the end of the fragment's lifetime. After the disappearance of the fragment, another light bridge formed in the parent which had similar properties as the fragmenting one, but did not divide the sunspot. The significant weakening in field strength in the light bridge along with the presence of granulation is suggestive of strong convection in the sunspot, which might have triggered the expulsion and fragmentation of the smaller spot. Although the presence of QS photospheric conditions in sunspot umbrae could be a necessary condition for

  20. Determination of lithium abundance in sunspots: Observations in 1973

    NASA Astrophysics Data System (ADS)

    Baranovsky, E. A.; Musorina, S. A.; Tarashchuk, V. P.

    2012-06-01

    Spectra of sunspots in the region of the lithium 6708 Å line, as well as certain CaI, AlI, FeI, YI, ScI, VI lines, were studied. The observations were performed on July 8, 1973 using a BST-2 telescope at the Crimean Astrophysical Observatory. A sunspot model was developed based on the observed profiles of CaI, AlI, FeI, YI, ScI, and VI lines. Using the developed model and observed profile of the Li 6708 Å line, the abundance of lithium was determined. The obtained result is log(NLi) = 0.95.

  1. 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. PMID:10827944

  2. Dynamical Characteristics of Sunspot Chromospheres. I. Analysis of Circular Polarization Measured from a Sunspot

    NASA Astrophysics Data System (ADS)

    Kil, Hyo Sub; Yun, Hong Sik

    1993-10-01

    We have analyzed a set of high resolution photographic line profiles of a Zeeman sensitive Fe I lambda 6302.5 line taken with the Universal Birefringent Filter over a single round sunspot (SPO 5007) at the Sacramento Peak Solar Observatory. The observed spectra recorded on films are traced by PDS and the traced densities are converted to relative intensity by means of IRAF. The Stokes I and V profiles are then constructed by adding together and subtracting from each other the left and right handed circular polarizations, respectively. The reduced I and V profiles are analyzed by means of the coarse analysis(Auer et al.(1977), Skumanich and Lites(1987)) with the use of inversion technique. It is found that the umbral field strength is about 3000 gauss and the field distribution follows closely the emperical model proposed by Wittmann(1974).

  3. Sunspots and the physics of magnetic flux tubes. I - The general nature of the sunspot. II - Aerodynamic drag

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1979-01-01

    Analysis of the dynamical stability of a large flux tube suggests that the field of a sunspot must divide into many separate tubes within the first 1000 km below the surface. Buoyancy of the Wilson depression at the visible surface and probably also a downdraft beneath the sunspot hold the separate tubes in a loose cluster. Convective generation of Alfven waves, which are emitted preferentially downward, cools the tubes. Aerodynamic drag on a slender flux tube stretched vertically across a convective cell is also studied. Since the drag is approximately proportional to the local kinetic energy density, the density stratification weights the drag in favor of the upper layers. Horizontal motions concentrated in the bottom of the convective cell may reverse this density effect. A downdraft of about two km/sec through the flux tubes beneath the sunspot is hypothesized.

  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. RAPID SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15

    SciTech Connect

    Jiang Yunchun; Zheng Ruisheng; Yang Jiayan; Hong Junchao; Yi Bi; Yang Dan

    2012-01-01

    We present observations of sunspot evolution associated with the first X-class flare of the present solar cycle 24, which occurred in AR 11158 on 2011 February 15. The active region consisted of four emerging bipoles that showed complicated sunspot motion. The preceding spot of a bipole underwent the fastest movement. It not only passed through the following end of another bipole, thus causing a shearing motion, but also merged with the same-polarity spots and formed a single, larger umbra. This led to the formation of a {delta} configuration with an S-shaped neutral line, above which an extreme ultraviolet filament channel and a sigmoid formed and erupted to produce the flare. Along with the development of a clockwise (CW) spiral penumbra-filament pattern, the merged spot started rapid CW rotation around its umbral center 20 hr before the flare. The rotation persisted throughout the flare but stopped sharply about 1 hr after the flare ended, maintaining the twisted penumbra-filament pattern. The moving spot also caused continuous flux cancellation; in particular, its outer penumbra directly collided with small opposite-polarity spots only 100 minutes before the flare. When the shearing and rotational motions are main contributors to the energy buildup and helicity injection for the flare, the cancellation and collision might act as a trigger. Our observations support the idea that the rotation can be attributed to the emergence of twisted magnetic fields, as proposed in recent theories. Finally, the cause of its sudden halt is discussed.

  6. Long-Term Changes in Sunspot Activity, Occurrence of Grand Minima, and Their Future Tendencies

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    Long-term changes in the magnetic activity of the Sun were studied in terms of the empirical mode decomposition that revealed their essential modes. The occurrence of grand minima was also studied in their relation to long-term changes in sunspot activity throughout the past 11 000 yr. Characteristic timescales of long-term changes in solar activity manifest themselves in the occurrence of grand minima. A quantitative criterion has been defined to identify epochs of grand minima. This criterion reveals the important role of secular and bicentennial activity variations in the occurrence of grand minima and relates their amplitudes with the current activity level, which is variable on a millennial timescale. We have revealed specific patterns in the magnetic activity between successive grand minima which tend to recur approximately every 2300 yr but occasionally alternate with irregular changes. Such intermittent activity behavior indicates low dimensional chaos in the solar dynamo due to the interplay of its dominant modes. The analysis showed that in order to forecast activity level in forthcoming cycles, one should take into account long-term changes in sunspot activity on a ≈2300-yr timescale. The regularities revealed suggest solar activity to decrease in the foreseeable future.

  7. Reporting accuracy of packed lunch consumption among Danish 11-year-olds differ by gender

    PubMed Central

    Lyng, Nina; Fagt, Sisse; Davidsen, Michael; Hoppe, Camilla; Holstein, Bjørn; Tetens, Inge

    2013-01-01

    Background Packed lunch is the dominant lunch format in many countries including Denmark. School lunch is consumed unsupervised, and self-reported recalls are appropriate in the school setting. However, little is known about the accuracy of recalls in relation to packed lunch. Objective To assess the qualitative recall accuracy of self-reported consumption of packed lunch among Danish 11-year-old children in relation to gender and dietary assessment method. Design A cross-sectional dietary recall study of packed lunch consumption. Digital images (DIs) served as an objective reference method to determine food items consumed. Recalls were collected with a lunch recall questionnaire (LRQ) comprising an open-ended recall (OE-Q) and a pre-coded food group prompted recall (PC-Q). Individual interviews (INTs) were conducted successively. The number of food items was identified and accuracy was calculated as match rates (% identified by DIs and reported correctly) and intrusion rates (% not identified by DIs but reported) were determined. Setting and subjects Three Danish public schools from Copenhagen. A total of 114 Danish 11-year-old children, mean (SE) age=11.1 (0.03), and body mass index=18.2 (0.26). Results The reference (DIs) showed that girls consumed a higher number of food items than boys [mean (SE) 5.4 (0.25) vs. 4.6 (0.29) items (p=0.05)]. The number of food items recalled differed between genders with OE-Q recalls (p=0.005) only. Girls’ interview recalls were more accurate than boys’ with higher match rates (p=0.04) and lower intrusion rates (p=0.05). Match rates ranged from 67–90% and intrusion rates ranged from 13–39% with little differences between girls and boys using the OE-Q and PC-Q methods. Conclusion Dietary recall validation studies should not only consider match rates as an account of accuracy. Intrusions contribute to over-reporting in non-validation studies, and future studies should address recall accuracy and inaccuracies in relation to

  8. 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).

  9. The EPICure Study: Association between Hemodynamics and Lung Function at 11 Years after Extremely Preterm Birth

    PubMed Central

    Bolton, Charlotte E.; Stocks, Janet; Hennessy, Enid; Cockcroft, John R.; Fawke, Joseph; Lum, Sooky; McEniery, Carmel M.; Wilkinson, Ian B.; Marlow, Neil

    2012-01-01

    Objective To investigate the relationship between disturbed lung function and large-artery hemodynamics in school-age children born extremely preterm (EP) (at 25 completed weeks of gestation or less). Study design This was a cross-sectional study of participants from the EPICure study, now aged 11 years (n = 66), and 86 age- and sex-matched term-born classmates. Spirometry parameters (including forced expiratory volume in 1 second), blood pressure, and augmentation index (AIx, a composite of arterial stiffness and global wave reflections) were measured. Results Compared with their classmates, the EP children had significantly impaired lung function, particularly those with neonatal bronchopulmonary dysplasia. Peripheral blood pressure did not differ significantly between the 2 groups, but AIx values were on average 5% higher (95% CI, 2%-8%) in the preterm infants, remaining significant after adjustment for potential confounders. Neonatal bronchopulmonary dysplasia status was not related to AIx. Lung function and maternal smoking were independently associated with AIx; AIx increased by 2.7% per z-score reduction in baseline forced expiratory volume in 1 second and by 4.9% in those whose mothers smoked during pregnancy. Conclusion The independent association between impaired lung function and cardiovascular physiology in early adolescence implies higher cardiovascular risk for children born EP, and suggests that prevention of chronic neonatal lung disease may be a priority in reducing later cardiovascular risk in preterm infants. PMID:22575246

  10. Spontaneous pneumomediastinum in an 11-year-old boy after a shallow breath-hold dive.

    PubMed

    Laitila, Maija; Eskola, Vesa

    2013-12-01

    Spontaneous pneumomediastinum is caused by pulmonary barotrauma due to transiently increased intra-alveolar and intra-bronchial pressure. The most frequent triggers of spontaneous pneumomediastinum in children are asthma and manoeuvres creating forced expiration. It has been rarely associated with breath-hold diving. Chest pain and dyspnoea are the main symptoms, and the diagnosis can be confirmed by chest X-ray. The treatment of choice is oxygen, analgesics and monitoring the patient. The recurrence rate is low. The main differential diagnoses of spontaneous pneumomediastinum are oesophageal perforation and pericarditis. We report a case of an 11-year-old boy with no substantial medical history, who tried to breath-hold in shallow water for as long as possible. After diving, he felt dyspnoea and chest pain. Chest X-ray revealed pneumomediastinum and subcutaneous emphysema. The patient was admitted to the PICU for observation and was discharged after two days' follow up. Spontaneous pneumomediastinum in children may be more common than thus far acknowledged. It requires a high index of suspicion and should be considered in all children with acute chest pain. PMID:24510332

  11. Hydration Deficit in 9- to 11-Year-Old Egyptian Children

    PubMed Central

    Gouda, Zaghloul; Zarea, Mohamed; El-Hennawy, Usama; Viltard, Mélanie; Lepicard, Eve; Hawili, Nasrine; Constant, Florence

    2015-01-01

    Background. Children who drink too little to meet their daily water requirements are likely to become dehydrated, and even mild dehydration can negatively affect health. This is even more important in Middle-Eastern countries where high temperatures increase the risk of dehydration. We assessed morning hydration status in a sample of 519 Egyptian schoolchildren (9-11 years old). Methods. Children completed a questionnaire on breakfast intakes and collected a urine sample after breakfast. Breakfast food and fluid nutritional composition was analyzed and urine osmolality was measured using osmometry. Results. The mean urine osmolality of children was 814 mOsmol/kg: >800 mOsmol/kg (57%) and >1000 mOsmol/kg (24.7%). Furthermore, the results showed that a total water intake of less than 400 mL was associated with a significant higher risk of dehydration. Surprisingly, 63% of the children skipped breakfast. Conclusions. The results showed that a majority of Egyptian schoolchildren arrive at school with a hydration deficit. These results highlight the fact that there is a need to educate schoolchildren about the importance of having a breakfast and adequate hydration. PMID:27335985

  12. Anemia and Iron Deficiency in Vietnamese Children, 6 to 11 Years Old.

    PubMed

    Le Nguyen Bao, Khanh; Tran Thuy, Nga; Nguyen Huu, Chinh; Khouw, Ilse; Deurenberg, Paul

    2016-07-01

    In a population sample of 385 children, 6 to 11 years old, venous blood parameters-hemoglobin (Hb), ferritin, red blood cell count (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), C-reactive protein (CRP), and α1-acid glycoprotein (AGP)-were determined to get insight into the iron status. The prevalence of anemia was 11.4%; 5.6% had iron deficiency (ID), whereas 0.4% had ID anemia. Correction for inflammation based on CRP and AGP did not markedly change the overall prevalence of ID and ID anemia. Stunted children had lower Hb and ferritin values compared with nonstunted children, and thin children had lower values compared with normal-weight or overweight and obese children. Many nonanemic children had alert values for RBC, MCV, MCH, and MCHC. It is concluded that although the prevalence of anemia is of the magnitude of a mild public health problem, the iron status of many nonanemic children is borderline, as indicated by a high number of children with low values for red blood cytology. PMID:27052301

  13. Assessment of bully/victim problems in 8 to 11 year-olds.

    PubMed

    Austin, S; Joseph, S

    1996-12-01

    The aim of the present study was to develop two six-item self-report scales (the Bullying-Behaviour Scale and the Peer-Victimisation Scale) to assess bully-victim problems at school. These scales were designed so that they could be immersed within the Self-Perception Profile for Children (SPPC: Harter, 1985) thus reducing the saliency of the items. Internal reliability of both scales was found to be satisfactory (Cronbach's alpha = 0.83 and 0.82 respectively). Data are reported on the association between scores on both scales and scores on the SPPC and the Birleson Depression Inventory (Birleson, 1981) with 425 children (204 boys and 221 girls) ranging from 8 to 11 years (mean = 9.2 years). Forty-six per cent of the children were classified as bullies, victims, or both: 22 per cent were classified as victims only, 15 per cent as bully/victims, and 9 per cent as bullies only. PMID:9008423

  14. Pneumomediastinum and Pneumopericardium in an 11-Year-Old Rugby Player: A Case Report

    PubMed Central

    Vanzo, Valentina; Bugin, Samuela; Snijders, Deborah; Bottecchia, Laura; Storer, Veronica; Barbato, Angelo

    2013-01-01

    Objective: Pneumomediastinum and pneumopericardium are rare occurrences in young athletes, but they can result in potentially life-threatening consequences. Background: While involved in a rugby match, an 11-year-old boy received a chest compression by 3 players during a tackle. He continued to play, but 2 hours later, he developed sharp retrosternal chest pain. A chest radiograph and an echocardiograph at the nearest emergency department showed pneumopericardium and pneumomediastinum. Differential Diagnosis: Sternal and rib contusions, rib fractures, heartburn, acute asthma exacerbation, pneumomediastinum, pneumopericardium, pneumothorax, traumatic tracheal rupture, myocardial infarction, and costochondritis (Tietze syndrome). Treatment: Acetaminophen for pain control. Uniqueness: To our knowledge, this is the only case in the international literature of the simultaneous occurrence of pneumomediastinum and pneumopericardium in a child as a consequence of blunt chest trauma during a rugby match. Conclusions: Pneumomediastinum and pneumopericardium may be consequences of rugby blunt chest trauma. Symptoms can appear 1 to 2 hours later, and the conditions may result in serious complications. Immediate admission to the emergency department is required. PMID:23672393

  15. Hypohydrotic ectodermal dysplasia: an unusual presentation and management in an 11-year-old Xhosa boy.

    PubMed

    Sarvan, I; Naidoo, S; Norval, E J

    2000-01-01

    Ectodermal dysplasia (ED) is an inherited disorder in which two or more ectodermally derived structures fail to develop, or are abnormal in development. Hypohydrotic ectodermal dysplasia (HED) or Christ-Siemens-Touraine syndrome, is an X-linked recessive syndrome with an incidence of 1/10,000 to 1/100,000 births. Because of its X-linked inheritance pattern, it is more common in males. HED is characterised by hypohydrosis (diminished perspiration), hypotrichosis (decreased amount of hair) and microdontia (small teeth), hypodontia (lack of development of one or more teeth) or adontia (total lack of tooth development). These patients present diagnostic and treatment challenges because of variable oral manifestations. This report describes an 11-year-old Xhosa boy, who was referred to the University Dental Faculty by his general medical practitioner because of hypodontia. General facial features included: frontal bossing, a depressed nasal bridge, 'butterfly' pattern of eczema over the nasal bridge to the malar process of each cheek, thinned out hair, loss of vertical dimension of face and dry skin. Intra-oral examination revealed hypodontia with peg-shaped anterior teeth and diastemas. Radiological examination revealed no developing permanent teeth or tooth buds. Diagnosis was confirmed by doing a sweat gland count. Management included oral hygiene instruction, fluoride treatments, construction of a partial lower denture and counselling about his condition with particular reference to the danger of hyperthermia and control of allergies. PMID:12608250

  16. Diagnosis and Treatment of Odontogenic Cutaneous Sinus Tracts in an 11-Year-Old Boy

    PubMed Central

    Chen, Ke; Liang, Yun; Xiong, Huacui

    2016-01-01

    Abstract Odontogenic cutaneous sinus tracts (OCSTs) are generally primarily misdiagnosed and inappropriately treated by virtue of their rarity and the absence of dental symptoms. Accurate diagnosis and treatment and the elimination of the source of infection can reduce the incidence of complications and relieve the pain of the patient. In this case report, we present the case of an 11-year-old patient with an apparent abscess but an unobvious draining sinus tract in his left cheek. Intraorally, a glass-ionomer-cement filling on the occlusal surface of the left mandibular first molar (tooth 36) was noted. Radiographic examination revealed a radiopaque mass inside the crown and pulp chamber and an irregular, radiolucent periapical lesion surrounding the distal root apex. He was diagnosed with an OCTS secondary to a periapical abscess of tooth 36. Precise root canal therapy (RCT) and chronic granuloma debridement was performed; 6 months later, the abscess and sinus had healed completely, and the periapical lesion had resolved. Odontogenic cutaneous sinus tracts are uncommon in the clinic. This case report reminds us of the significance of OCSTs and provides some implications for their diagnosis and treatment. PMID:27196471

  17. The occurrence of an abdominal wall abscess 11 years after appendectomy: report of a case.

    PubMed

    Matsuda, K; Masaki, T; Toyoshima, O; Ono, M; Muto, T

    1999-01-01

    Most complications after appendectomy occur within 10 days; however, we report herein the unusual case of a patient in whom a wound abscess was detected more than 10 years after an appendectomy. A 26-year-old woman presented to our hospital with nausea and vomiting, pain, and a mass in the right lower abdominal wall. She had undergone an appendectomy 11 years previously. Physical examination revealed a tender mass, 5 cm in diameter, under the appendectomy scar. An abdominal ultrasonography demonstrated a low-echoic mass lesion measuring 9.0 x 5.0 x 2.0 cm. Incision of the connective tissue revealed about 3 ml of cream-colored and odorless fluid in the abscess cavity. Fistulography revealed an abscess cavity not communicating with the bowel lumen. Floss was discovered in the connective tissue and removed. Debridement of the abscess wall was performed and a piece of the wall was sent for histologic examination. Pathological examination revealed panniculitis of the subcutaneous tissue, and panniculitis with granulation and granuloma of the abscess wall. This case report demonstrates that a preoperative diagnosis should be based not on one finding, but on all findings collected, inclusively. PMID:10489140

  18. Acceptance of Nordic snack bars in children aged 8–11 years

    PubMed Central

    Holmer, Anna; Hausner, Helene; Reinbach, Helene C.; Bredie, Wender L. P.; Wendin, Karin

    2012-01-01

    Background A health promoting diet is suggested to be tailored to regional circumstances to preserve the cultural diversity in eating habits, as well as contribute to more environmentally friendly eating. It may influence consumer acceptance, however, if the components of the diet differs considerably from their habitual food. Objective This study aimed to investigate whether snack bars composed of Nordic ingredients were accepted by 8–11 year-old Danish (n=134) and Swedish (n=109) children. Design A seven-point hedonic scale was used to measure the children's acceptance of five snack bars that varied in their composition of whole grains, berries and nuts. A preference rank ordering of the five bars was also performed. Results The results showed that samples that were rated highest in liking and were most preferred in both countries were a kamut/pumpkin bar and an oat/cranberry bar. The sample with the lowest rating that was also least preferred was a pumpernickel/sea buckthorn bar. Flavour was the most important determinant of overall liking followed by texture, odour and appearance. Conclusions Children's acceptances and preferences were highly influenced by the sensory characteristics of the bars, mainly flavour. In agreement with earlier studies, the novel food ingredients seemed to influence children's preferences. The Nordic snack bars may have a potential to be a snack option for Danish and Swedish school children, but repeated exposures to the products are recommended to increase children's acceptance. PMID:22545034

  19. Facial reconstruction of an 11-year-old female resident of 430 BC Athens.

    PubMed

    Papagrigorakis, Manolis J; Synodinos, Philippos N; Antoniadis, Aristomenis; Maravelakis, Emmanuel; Toulas, Panagiotis; Nilsson, Oscar; Baziotopoulou-Valavani, Effie

    2011-01-01

    Although modern standards of ideal proportions and facial esthetics are based mostly on observations of human faces as depicted in Classical Greek masterpieces of art, the real faces of ordinary ancient Greeks have, until now, remained elusive and subject to the imagination. Objective forensic techniques of facial reconstruction have never been applied before, because human skeletal material from Classical Greece has been extremely scarce, since most decent burials of that time required cremation. Here, the authors show stage by stage the facial reconstruction of an 11-year-old girl whose skull was unearthed in excellent condition from a mass grave with victims of the Plague that struck Athens of 430 bc. The original skull was replicated via three-dimensional modeling and rapid prototyping techniques. The reconstruction followed the Manchester method, laying the facial tissues from the surface of the skull outward by using depth-marker pegs as thickness guides. The shape, size, and position of the eyes, ears, nose, and mouth were determined according to features of the underlying skeletal tissues, whereas the hairstyle followed the fashion of the time. This is the first case of facial reconstruction of a layperson residing in Athens of the Golden Age of Pericles. It is ironic, however, that this unfortunate girl who lived such a short life in ancient Athens, will now, 2500 years later, have the chance to travel and be universally recognizable in a world much bigger than anybody in ancient Athens could have ever imagined. PMID:20936971

  20. 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. PMID:20227801

  1. Very Late Stent Thrombosis 11 Years after Implantation of a Drug-Eluting Stent

    PubMed Central

    Jepson, Nigel

    2015-01-01

    Very late stent thrombosis is an infrequent yet potentially fatal complication associated with drug-eluting stents. We report the case of an 88-year-old man who sustained an ST-segment-elevation myocardial infarction 11 years after initial sirolimus-eluting stent implantation. Optical coherence tomograms of the lesion showed that the focal incomplete endothelialization of the stent struts was the likely cause; neointimal formation, neoatherosclerosis, and late stent malapposition might also have contributed. To our knowledge, this is the longest reported intervening period between stent insertion and the development of an acute coronary event secondary to very late stent thrombosis. The associated prognostic and therapeutic implications are considerable, because they illuminate the uncertainties surrounding the optimal duration of antiplatelet therapy in patients who have drug-eluting stents. Clinicians face challenges in treating these patients, particularly when competing medical demands necessitate the discontinuation of antiplatelet therapy. In addition to the patient's case, we discuss factors that can contribute to very late stent thrombosis. PMID:26504449

  2. Solar Cycle Characteristics and Their Relationship with Dynamo Theory

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. 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.

  4. Three-Dimensional Chromospheric Thermal Structure of Sunspots

    NASA Astrophysics Data System (ADS)

    Prasad Choudhary, Debi; Beck, Christian

    2016-05-01

    We have observed several sunspots using the Spectropolarimeter for Infrared and Optical wavelength Ranges at the Dunn Solar Telescope during 29 July to 4 August 2013. The data consists of full Stokes profiles in the Ca II 854.2 nm and Fe I 1.56 micron lines. The inversion of these Stokes spectra provides the magnetic, thermal and velocity structure at photospheric and chromospheric heights of sunspots. In this contribution, we present the results on the 3D thermal structure in the super-penumbral canopy of a round sunspot, derived by a novel approach for the inversion of Ca II IR spectra. Tracing individual fibrils in the super-penumbral canopy, we find that about half of them form only short loops of a a few Mm length that return to the photosphere in the close surroundings of the sunspot instead of connecting to more remote magnetic network at the outer end of the moat flow. We also find indications for standing shocks at the inner foot points of the flow channels that are compatible with a supersonic siphon flow scenario.

  5. 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.

  6. Illegal Substance Use among Italian High School Students: Trends over 11 Years (1999–2009)

    PubMed Central

    Molinaro, Sabrina; Siciliano, Valeria; Curzio, Olivia; Denoth, Francesca; Salvadori, Stefano; Mariani, Fabio

    2011-01-01

    Purpose To monitor changes in habits in drug use among Italian high school students. Methods Cross-sectional European School Survey Project on Alcohol and Other Drugs (ESPAD) carried out in Italy annually for 11 years (1999–2009) with representative samples of youth attending high school. The sample size considered ranges from 15,752 to 41,365 students and response rate ranged from 85.5% to 98.6%. Data were analyzed to obtain measures of life-time prevalence (LT), use in the last year (LY), use in the last 30 days (LM), frequent use. Comparisons utilized difference in proportion tests. Tests for linear trends in proportion were performed using the Royston p trend test. Results When the time-averaged value was considered, cannabis (30% LT) was the most, and heroin the least (2%) frequently used, with cocaine (5%), hallucinogens (2%) and stimulants (2%) in between. A clear gender gap is evident for all drugs, more obvious for hallucinogens (average M/F LY prevalence ratio 2, range 1.7–2.4, p<0.05), less for cannabis (average M/F LY prevalence ratio 1.3, range 1.2–1.5, p<0.05). Data shows a change in trend between 2005 and 2008; in 2006 the trend for cannabis use and availability dropped and the price rose, while from 2005 cocaine and stimulant use prevalence showed a substantial increase and the price went down. After 2008 use of all substances seems to have decreased. Conclusions Drug use is widespread among students in Italy, with cannabis being the most and heroin the least prevalent. Girls are less vulnerable than boys to illegal drug use. In recent years, a decrease in heroin use is overbalanced by a marked rise in hallucinogen and stimulant use. PMID:21695199

  7. An 11-year retrospective review of venlafaxine ingestion in children from the California Poison Control System.

    PubMed

    Doroudgar, S; Perry, P J; Lackey, G D; Veselova, N G; Chuang, H M; Albertson, T E

    2016-07-01

    Venlafaxine is commonly used in the United States for approved and non-Food and Drug Administration-approved indications in adults. It is used off-label to treat children for psychiatric diagnoses. The aim of the study was to describe venlafaxine toxicities in children and to identify the venlafaxine dose per weight that correlates with toxicities. An 11-year retrospective study of venlafaxine ingestion in children was performed using the California Poison Control System (CPCS) database. Data was extracted from phone calls received by CPCS clinicians and follow-up phone calls made to assess the patient's progress in a health-care setting. Inclusion criteria were venlafaxine ingestion cases reported to CPCS between January 2001 and December 2011, children aged 20 years and under, venlafaxine as the only ingested substance, managed in a health-care facility, and followed to a known outcome. Two hundred sixty-two cases met the study criteria. Common presentations included gastrointestinal (14.9%), altered mental status (13.7%), and tachycardia (13.4%). The majority of the cases resulted in no effect (51.5%) or minor effect (19.9%). The average estimated dose per weight was 18.3 mg/kg in all patients and 64.5 mg/kg in those experiencing moderate-to-severe adverse effects. Seizures occurred in only 4 of the 262 cases at doses ranging from 1500 to 7500 mg. Although the estimated dose per weight exceeded 10 mg/kg for the majority of the cases, only 12 cases resulted in moderate or severe outcomes. The majority of venlafaxine ingestion cases in children resulted in either no clinical effects or minor clinical effects. PMID:26351291

  8. Trauma, mental health, and intergenerational associations in Kosovar Families 11 years after the war

    PubMed Central

    Schick, Matthis; Morina, Naser; Klaghofer, Richard; Schnyder, Ulrich; Müller, Julia

    2013-01-01

    Background While there is a considerable amount of literature addressing consequences of trauma in veterans and holocaust survivors, war and postwar civilian populations, particularly children, are still understudied. Evidence regarding intergenerational effects of trauma in families is inconsistent. Objective To shed light on intergenerational aspects of trauma-related mental health problems among families 11 years after the Kosovo war. Method In a cross-sectional study, a paired sample of 51 randomly selected triplets (school-aged child, mother, father, N=153) of Kosovar families was investigated with regard to trauma exposure, posttraumatic stress (UCLA Posttraumatic Diagnostic Scale), anxiety (Spence Children's Anxiety Scale, Hopkins Symptom Checklist-25), and depressive symptoms (Depressionsinventar für Kinder und Jugendliche [DIKJ; depression inventory for children and adolescents], Hopkins Symptom Checklist-25). Results Considerable trauma exposure and high prevalence rates of clinically relevant posttraumatic stress, anxiety, and depressive symptoms were found in both parents and children. While strong correlations were found between children's depressive symptoms and paternal posttraumatic stress, anxiety and depressive symptoms, maternal symptoms did not correlate with their children's. In multiple regression analyses, only posttraumatic stress symptoms of fathers were significantly related with children's depressive symptoms. Conclusion Eleven years after the Kosovo war, the presence of posttraumatic stress, anxiety, and depressive symptoms in civilian adults and their children is still substantial. As symptoms of parents and children are associated, mental health problems of close ones should be actively screened and accounted for in comprehensive treatment plans, using a systemic approach. Future research should include longitudinal studies conducting multivariate analyses with larger sample sizes in order to investigate indicators, causal and

  9. Antimicrobial Susceptibility of Invasive Streptococcus pneumoniae Isolates in Portugal over an 11-Year Period

    PubMed Central

    Dias, Ricardo; Louro, Deolinda; Caniça, Manuela

    2006-01-01

    This national surveillance study presents the in vitro activities of the main antimicrobial agents against 1,331 S. pneumoniae isolates as tested by an agar dilution method according to the guidelines of the Clinical and Laboratory Standards Institute (formerly NCCLS). The strains were isolated in several regions of Portugal from cases of invasive disease over an 11-year period (1994 to 2004). This study shows that the percentage of penicillin-nonsusceptible strains increased from 12% in 1994 to 28.5% in 2000. Then the rate declined to 17.7% in 2003 but increased again to 23.2% in 2004. Nevertheless, the rate of highly resistant isolates declined consistently, to 0.9% in 2001 to 2004. Ceftriaxone- and cefotaxime-nonsusceptible isolates became less frequent, from 4% and 8%, respectively, in 1994 to ≤1% in 2004. The macrolide-lincosamide-streptogramin B phenotype was the predominant macrolide phenotype found. The increase in the percentage of isolates that were only nonsusceptible to erythromycin (3.7% in 1994 to 1998 to 9.1% in 2002 to 2004) was similar to that for isolates with coresistance to penicillin and erythromycin (3.3% in 1994 to 1998 to 9.1% in 2002 to 2004). The nonsusceptibility to ciprofloxacin increased during recent years, from 0.5% in 2002 to 3.5% in 2004. Multidrug resistance also increased in recent years: from 7.9% in 2002 to 15.6% in 2004. The increasing use of macrolides could be causing the increase in penicillin and multidrug resistance, due to the coresistance to macrolides. The use of penicillin to treat empirical invasive pneumococci infections may need to be reconsidered. PMID:16723571

  10. 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

  11. 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. PMID:27219739

  12. Manual control age and sex differences in 4 to 11 year old children.

    PubMed

    Flatters, Ian; Hill, Liam J B; Williams, Justin H G; Barber, Sally E; Mon-Williams, Mark

    2014-01-01

    To what degree does being male or female influence the development of manual skills in pre-pubescent children? This question is important because of the emphasis placed on developing important new manual skills during this period of a child's education (e.g. writing, drawing, using computers). We investigated age and sex-differences in the ability of 422 children to control a handheld stylus. A task battery deployed using tablet PC technology presented interactive visual targets on a computer screen whilst simultaneously recording participant's objective kinematic responses, via their interactions with the on-screen stimuli using the handheld stylus. The battery required children use the stylus to: (i) make a series of aiming movements, (ii) trace a series of abstract shapes and (iii) track a moving object. The tasks were not familiar to the children, allowing measurement of a general ability that might be meaningfully labelled 'manual control', whilst minimising culturally determined differences in experience (as much as possible). A reliable interaction between sex and age was found on the aiming task, with girls' movement times being faster than boys in younger age groups (e.g. 4-5 years) but with this pattern reversing in older children (10-11 years). The improved performance in older boys on the aiming task is consistent with prior evidence of a male advantage for gross-motor aiming tasks, which begins to emerge during adolescence. A small but reliable sex difference was found in tracing skill, with girls showing a slightly higher level of performance than boys irrespective of age. There were no reliable sex differences between boys and girls on the tracking task. Overall, the findings suggest that prepubescent girls are more likely to have superior manual control abilities for performing novel tasks. However, these small population differences do not suggest that the sexes require different educational support whilst developing their manual skills. PMID

  13. 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. PMID:23091632

  14. Coroner autopsy study of homicides in Rivers State of Nigeria: 11-year review.

    PubMed

    Obiorah, C C; Amakiri, C N

    2014-01-01

    As most developing countries, including Nigeria, grapple with economic crisis, poor human capital development and high levels of income inequality, violent crimes - especially homicides - continue to be a cause for concern. We studied the pathology and demographic distribution of homicides in Rivers State of Nigeria expecting that the findings would be useful in formulating preventive strategies. Reports of homicide autopsies in the state for 11 years were retrospectively scrutinized for age, gender, type of weapon, site of injury, circumstances, mechanisms and causes of death. The data were analyzed using SPSS version 17. Homicides constituted 50.5% of the medicolegal autopsies. Although the overall male:female ratio was 12.4 : 1, there was variation with weapon. Deaths by firearm had the highest male:female ratio of 24.6 : 1. The mean and peak ages were 29.2 ± 11.4 and 21-30 years, respectively, while the range was 1 to 96 years. Firearms were the most common weapons, at 68.9%, hemorrhagic shock and head injuries at 61.5% and 28.2% respectively were the most common mechanisms and causes of death. Armed robbery incidents were the most common circumstances, while the head was the most common site of injury at 48.8%. The homicide rate is high in our environment and most homicides are committed during armed robberies using firearms. Improving medical care and providing emergency medical services will reduce cases of deaths from homicides, most of which occur due to manageable hemorrhagic shock. Increasing the drive towards controlling illegal arms acquisition and possession will reduce the present carnage in the state. PMID:23945261

  15. 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. PMID:18995850

  16. 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.

  17. 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.

  18. 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.

    2016-06-01

    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.

  19. Climate changes and solar cycles recorded at the Holocene Paraná Delta, and their impact on human population.

    PubMed

    Milana, Juan Pablo; Kröhling, Daniela

    2015-01-01

    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. PMID:26246410

  20. 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

  1. 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.

  2. 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

  3. 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

  4. Non-insulin-dependent diabetes and 11-year mortality in Asian Indian and Melanesian Fijians.

    PubMed

    Collins, V R; Dowse, G K; Ram, P; Cabealawa, S; Zimmet, P Z

    1996-02-01

    This study reports 11-year all-cause and cause-specific mortality rates according to baseline glucose tolerance for a population-based sample of adult Melanesian and Indian Fijians (n = 2638), first surveyed in 1980. Risk factors for all-cause and cardiovascular disease (CVD) mortality in subjects with non-insulin-dependent diabetes (NIDDM) are also described. The baseline survey included 75 g oral glucose tolerance tests, measurements of blood pressure, body mass index, and triceps skinfold, assays of plasma cholesterol and triglycerides, electrocardiograms, and details of smoking habits and physical activity. Mortality status was ascertained for 2546 subjects through surveillance of death certificates, medical records and interview of subjects (or relatives). Mortality rates were increased in diabetic men and women of both ethnic groups: relative risks compared to subjects without diabetes at baseline were 1.7 (CI:0.9-3.1) and 2.0 (1.1-3.7) in Melanesian and 4.2 (2.7-6.5), 3.2 (1.9-5.7) in Indian men and women, respectively. A large proportion of mortality among diabetic subjects was attributed to CVD (62%, 66% in Melanesian and 54%, 58% in Indian men and women, respectively). Mortality rates tended to be higher in Melanesians than Indians, except for diabetic men where Indians had higher total and cardiovascular disease rates. In contrast to non-diabetic Fijians, diabetic women of both ethnic groups lost their relative protection from coronary heart disease (CHD). Cox regressions for diabetic subjects showed age and fasting plasma glucose to be independent predictors of all-cause mortality in men, and age, body mass index (inversely) and systolic blood pressure in women, but lipid concentrations, and cigarette smoking were not related. After accounting for conventional CVD risk factors, diabetes conferred significantly increased risk of total, CVD, and CHD mortality. The mortality experience of Melanesian and Indian Fijians with NIDDM is similar to that

  5. MDR-TB Outbreak among HIV-Negative Tunisian Patients followed during 11 Years

    PubMed Central

    Dekhil, Naira; Meftahi, Nedra; Mhenni, Besma; Ben Fraj, Saloua; Haltiti, Raja; Belhaj, Sameh; Mardassi, Helmi

    2016-01-01

    Background Multidrug-resistant tuberculosis (MDR-TB) outbreaks that evolve, from the outset, in a context strictly negative for HIV infection deserve special consideration since they reflect the true intrinsic epidemic potential of the causative strain. To our knowledge, the long-term evolution of such exceptional outbreaks and the treatment outcomes for the involved patients has never been reported hitherto. Here we provide a thorough description, over an 11-year period, of an MDR-TB outbreak that emerged and expanded in an HIV-negative context, Northern Tunisia. Methodology/Principal Findings From October 2001 to June 2011, the MDR-TB outbreak involved 48 HIV-negative individuals that are mainly young (mean age 31.09 yrs; 89.6% male) and noninstitutionalized. Drug susceptibility testing coupled to mutational analysis revealed that initial transmission involved an isolate that was simultaneously resistant to isoniazid, rifampicin, ethambutol, and streptomycin. The causative Haarlem3-ST50 outbreak strain expanded mainly as an 11-banded IS6110 RFLP profile (77.1%), from which a 12-banded subclone evolved. After undergoing a 2-year treatment with second-line drugs, 22 (45.8%) patients were cured and 3 (6.2%) completed treatment, thus yielding an overall treatment success rate of 52.1%. Among the patients that experienced unfavorable treatment outcomes, 10 (20.8%) failed treatment, 3 (6.2%) were lost to follow-up, 5 (10.4%) died, and 5 (10.4%) could not be evaluated. Poor adherence to treatment was found to be the main independent predictor of unfavorable outcomes (HR: 9.15; 95% CI 1.72–48.73; P = 0.014). Intriguingly, the evolved 12-banded subclone proved significantly associated with unfavorable outcomes (HR: 4.90; 95% CI 1.04–23.04, P = 0.044). High rate of fatality and relapse was further demonstrated at the long-term, since 70% of those whose treatment failed have died, and 24% among those deemed successfully treated have relapsed. Conclusions

  6. Sunspot rotation. I. A consequence of flux emergence

    NASA Astrophysics Data System (ADS)

    Sturrock, Z.; Hood, A. W.; Archontis, V.; McNeill, C. M.

    2015-10-01

    Context. Solar eruptions and high flare activity often accompany the rapid rotation of sunspots. The study of sunspot rotation and the mechanisms driving this motion are therefore key to our understanding of how the solar atmosphere attains the conditions necessary for large energy release. Aims: We aim to demonstrate and investigate the rotation of sunspots in a 3D numerical experiment of the emergence of a magnetic flux tube as it rises through the solar interior and emerges into the atmosphere. Furthermore, we seek to show that the sub-photospheric twist stored in the interior is injected into the solar atmosphere by means of a definitive rotation of the sunspots. Methods: A numerical experiment is performed to solve the 3D resistive magnetohydrodynamic equations using a Lagrangian-Remap code. We track the emergence of a toroidal flux tube as it rises through the solar interior and emerges into the atmosphere investigating various quantities related to both the magnetic field and plasma. Results: Through detailed analysis of the numerical experiment, we find clear evidence that the photospheric footprints or sunspots of the flux tube undergo a rotation. Significant vertical vortical motions are found to develop within the two polarity sources after the field emerges. These rotational motions are found to leave the interior portion of the field untwisted and twist up the atmospheric portion of the field. This is shown by our analysis of the relative magnetic helicity as a significant portion of the interior helicity is transported to the atmosphere. In addition, there is a substantial transport of magnetic energy to the atmosphere. Rotation angles are also calculated by tracing selected fieldlines; the fieldlines threading through the sunspot are found to rotate through angles of up to 353° over the course of the experiment. We explain the rotation by an unbalanced torque produced by the magnetic tension force, rather than an apparent effect. The movies

  7. Empirical solar/stellar cycle simulations

    NASA Astrophysics Data System (ADS)

    Santos, Ângela R. G.; Cunha, Margarida S.; Avelino, Pedro P.

    2015-09-01

    As a result of the magnetic cycle, the properties of the solar oscillations vary periodically. With the recent discovery of manifestations of activity cycles in the seismic data of other stars, the understanding of the different contributions to such variations becomes even more important. With this in mind, we built an empirical parameterised model able to reproduce the properties of the sunspot cycle. The resulting simulations can be used to estimate the magnetic-induced frequency shifts.

  8. 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.

  9. Peculiarity of the Oscillation Stratification in Sunspot Penumbrae

    NASA Astrophysics Data System (ADS)

    Kolobov, D. Y.; Chelpanov, A. A.; Kobanov, N. I.

    2016-07-01

    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 uc(i) 6173 Å, 1700 Å, and He uc(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.

  10. Emerging Flux Tube Geometry and Sunspot Proper Motions

    NASA Astrophysics Data System (ADS)

    van Driel-Gesztelyi, Lidia

    As sunspots appear at the intersection of rising flux tubes with the photosphere, the observed proper motions of a bipolar sunspot pair is a good indicator of the geometry of the underlying emerging flux tube. An emerging bipole caused by a simple symmetric potential flux tube should display a symmetric divergence of the two spots in diametrically opposite directions, while the proper motions of bipolar spot-pairs belonging to tilted or/and twisted (non-potential) emerging flux tubes are more complicated: asymmetric, not diametrically opposite and may follow a curved pattern. Observation of such motions may help to prove that emerging flux tubes are tilted and frequently twisted, in good agreement with predictions by recent simulation studies.

  11. Equivalence Relations Between the Cortie and Zürich Sunspot Group Morphological Classifications

    NASA Astrophysics Data System (ADS)

    Carrasco, V. M. S.; Lefèvre, L.; Vaquero, J. M.; Gallego, M. C.

    2015-05-01

    Catalogues of sunspots have been available with useful information about sunspots or sunspot groups for approximately the last 150 years. However, the task of merging these catalogues is not simple. We suggest a method of converting the types of sunspot groups that was proposed by Cortie ( Astrophys. J. 13, 260, 1901) into the well-known Zürich types of sunspot groups. To achieve this, we used the sunspot catalogue of the Valencia University Observatory (from 1920 to 1928) in addition to the descriptions proposed by Cortie. To assess the quality of this conversion scheme, the Zürich type was computed from the Valencia catalogue, and the resulting contribution of each group type was compared to what can be found in other catalogues. The results show that the proposed scheme works well within the errors that are found in the different catalogues.

  12. Methodical problems of magnetic field measurements in umbra of sunspots

    NASA Astrophysics Data System (ADS)

    Lozitska, N. I.; Lozitsky, V. G.; Andryeyeva, O. A.; Akhtemov, Z. S.; Malashchuk, V. M.; Perebeynos, V. A.; Stepanyan, N. N.; Shtertser, N. I.

    2015-02-01

    Visual measurements of magnetic field strengths in sunspot umbra provide data on magnetic field strength modulus directly, i.e., irrespective from any solar atmosphere model assumptions. In order to increase the accuracy of calculation of the solar magnetic indexes, such as B ‾ max or Bsp, the inclusion of all available data from different observatories is needed. In such measurements some methodical problems arise, which bring about inconsistency of the data samples combined from different sources; this work describes the problems at hand and proposes solutions on how to eliminate the inconsistencies. Data sets of sunspot magnetic field strength visual measurements from Mt. Wilson, Crimea and Kyiv observatories in 2010-2012 have been processed. It is found that two measurement modes of Zeeman split, σ → σ and σ → π, yield almost the same results, if data rows are long enough (over ∼100 sunspots in central area of Sun, r < 0.7 R). It is generally held that the most reliable measurement results are obtained for magnetic fields that exceed 2400 G. However, the empirical comparison of the internal data consistency of the samples produced by different observers shows that for reliable results this limit can be lowered down to 1100 G. To increase the precision of measurements, empirical calibration of the line-shifter is required by using closely positioned telluric lines. Such calibrations have been performed at Kyiv and Crimea, but as far as we know, it has not been carried out at Mt. Wilson observatory after its diffraction grate was replaced in 1994. Taking into consideration the highest quality and coverage of Mt. Wilson sunspot observational data, the authors are convinced that reliable calibration of its instrument by narrow telluric lines is definitely required.

  13. 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.

  14. DISTRIBUTION OF FORCED VITAL CAPACITY AND FORCED EXPIRATORY VOLUME IN ONE SECOND IN CHILDREN 6 TO 11 YEARS OF AGE

    EPA Science Inventory

    The authors analyzed 44,664 annual measurements of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) in 12,258 white children and 1,041 black children between 6 and 11 years of age in 6 communities. Sex and race-specific lung function development is de...

  15. 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,…

  16. 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…

  17. 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…

  18. 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…

  19. 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)

  20. Testing Effectiveness of a Community-Based Aggression Management Program for Children 7 to 11 Years Old and Their Families.

    ERIC Educational Resources Information Center

    Lipman, Ellen L.; Boyle, Michael H.; Cunningham, Charles; Kenny, Meghan; Sniderman, Carrie; Duku, Eric; Mills, Brenda; Evans, Peter; Waymouth, Marjorie

    2006-01-01

    Objective: There are few well-evaluated uncomplicated community-based interventions for childhood aggression. The authors assess the impact of a community-based anger management group on child aggressive behaviors, using a randomized, controlled trial (RCT). Method: Families with children 7 to 11 years old were recruited through advertisements and…

  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. 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 ...

  3. 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…

  4. 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 flagged and…

  5. 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…

  6. 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. PMID:21566725

  7. BLOOD PRESSURE, HEART RATE AND MELATONIN CYCLES SYNCHRONIZATION WITH THE SEASON, EARTH MAGNETISM AND SOLAR FLARES

    PubMed Central

    Cornélissen, G.; Halberg, F.; Sothern, R.B.; Hillman, D.C.; Siegelová, J.

    2010-01-01

    the 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. PMID:21566725

  8. Sunspot Observations of Rudolf Wolf from 1849 - 1893

    NASA Astrophysics Data System (ADS)

    Friedli, Thomas K.

    2016-06-01

    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.

  9. Modeling the Chromosphere of a Sunspot and the Quiet Sun

    NASA Astrophysics Data System (ADS)

    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.

  10. RADIATIVE HYDRODYNAMIC SIMULATIONS OF ACOUSTIC WAVES IN SUNSPOTS

    SciTech Connect

    Bard, S.; Carlsson, M.

    2010-10-10

    We investigate the formation and evolution of the Ca II H line in a sunspot. The aim of our study is to establish the mechanisms underlying the formation of the frequently observed brightenings of small regions of sunspot umbrae known as 'umbral flashes'. We perform fully consistent NLTE radiation hydrodynamic simulations of the propagation of acoustic waves in sunspot umbrae and conclude that umbral flashes result from increased emission of the local solar material during the passage of acoustic waves originating in the photosphere and steepening to shock in the chromosphere. To quantify the significance of possible physical mechanisms that contribute to the formation of umbral flashes, we perform a set of simulations on a grid formed by different wave power spectra, different inbound coronal radiation, and different parameterized chromospheric heating. Our simulations show that the waves with frequencies in the range 4.5-7.0 mHz are critical to the formation of the observed blueshifts of umbral flashes while waves with frequencies below 4.5 mHz do not play a role despite their dominance in the photosphere. The observed emission in the Ca II H core between flashes only occurs in the simulations that include significant inbound coronal radiation and/or extra non-radiative chromospheric heating in addition to shock dissipation.

  11. 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

  12. On diurnal variations of the solar rotation rate as derived from sunspot tracings

    NASA Astrophysics Data System (ADS)

    Koch, A.; Woehl, H.; Schroeter, E. H.

    1981-06-01

    The heliographic positions of more than 100 sunspots were accurately measured several times a day from 1974 until 1979 by means of the computer-controlled tracking method described by Schroeter and Woehl (1975). A striking degree of constancy of the solar rotation rate (about 0.15% or 3 m/s) is found, when east-west proper motion components of each individual stable sunspot is considered. However, large differences of the rotation rate are observed (up to 7% or 130 m/s) when comparing different sunspots. We found no significant correlation of these fluctuations with characteristics of the sunspots (age, evolution, etc.).

  13. 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

  14. Solar Cycle 24: Where are you?

    NASA Astrophysics Data System (ADS)

    Chapman, Gary A.; Cookson, A.; Preminger, D.

    2009-05-01

    Photometric images have been obtained on a daily basis since 1986 at the San Fernando Observatory. We will compare sunspot and facular areas from cycle 22 with those of cycle 23. Both spot areas and facular areas were lower during the maximum of cycle 23 compared to cycle 22. The distribution in spot areas will be compared. The extended minimum in spot area following cycle 23 is delaying the beginning of cycle 24. This work has been partially supported by NSF grant ATM-0533511.

  15. 11 Years of Cloud Characteristics from SEVIRI: 2nd Edition of the CLAAS Dataset by CMSAF

    NASA Astrophysics Data System (ADS)

    Finkensieper, Stephan; Stengel, Martin; Fokke Meirink, Jan; van Zadelhoff, Gerd-Jan; Kniffka, Anke

    2016-04-01

    Spatiotemporal variability of clouds is an important aspect of the climate system. Therefore climate data records of cloud properties are valuable to many researchers in the climate community. The passive SEVIRI imager onboard the geostationary Meteosat Second Generation satellites is well suited for the needs of cloud retrievals as it provides measurements in 12 spectral channels every 15 minutes and thus allows for capturing both the spatial and the temporal variability of clouds. However, requirements on climate data records are high in terms of record length and homogeneity, so that intercalibration and homogenization among the available SEVIRI instruments becomes a crucial factor. We present the 2nd edition of the CLoud Property DAtAset using SEVIRI (CLAAS-2) generated within the EUMETSAT Satellite Application Facility on Climate Monitoring (CMSAF), that is temporally extended and qualitatively improved compared to the 1st edition. CLAAS-2 covers the time period 2004-2014 and features cloud mask, cloud top properties, cloud phase, cloud type, and microphysical cloud properties on the complete SEVIRI disc in 15-minute temporal resolution. Temporally and spatially averaged quantities, mean diurnal cycles and monthly histograms are included as well. CLAAS-2 was derived from a homogenized data basis, obtained by intercalibrating visible and infrared SEVIRI radiances (of Meteosat 8, 9 and 10) with MODIS, using state-of-the-art retrieval schemes. In addition to the dataset characteristics, we will present validation results using CALIPSO as reference observations. The CLAAS-2 dataset will allow for a large variety of applications of which some will be indicated in our presentation, with focus on determining diurnal to seasonal cycles, spatially resolved frequencies of cloud properties as well as showing the potential for using CLAAS-2 data for model process studies.

  16. Gauging the Nearness and Size of Cycle Minimum

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  17. 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.

  18. 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.

  19. Thermospheric density model biases at the 23rd sunspot maximum

    NASA Astrophysics Data System (ADS)

    Pardini, C.; Moe, K.; Anselmo, L.

    2012-07-01

    Uncertainties in the neutral density estimation are the major source of aerodynamic drag errors and one of the main limiting factors in the accuracy of the orbit prediction and determination process at low altitudes. Massive efforts have been made over the years to constantly improve the existing operational density models, or to create even more precise and sophisticated tools. Special attention has also been paid to research more appropriate solar and geomagnetic indices. However, the operational models still suffer from weakness. Even if a number of studies have been carried out in the last few years to define the performance improvements, further critical assessments are necessary to evaluate and compare the models at different altitudes and solar activity conditions. Taking advantage of the results of a previous study, an investigation of thermospheric density model biases during the last sunspot maximum (October 1999 - December 2002) was carried out by analyzing the semi-major axis decay of four satellites: Cosmos 2265, Cosmos 2332, SNOE and Clementine. Six thermospheric density models, widely used in spacecraft operations, were analyzed: JR-71, MSISE-90, NRLMSISE-00, GOST-2004, JB2006 and JB2008. During the time span considered, for each satellite and atmospheric density model, a fitted drag coefficient was solved for and then compared with the calculated physical drag coefficient. It was therefore possible to derive the average density biases of the thermospheric models during the maximum of the 23rd solar cycle. Below 500 km, all the models overestimated the average atmospheric density by amounts varying between +7% and +20%. This was an inevitable consequence of constructing thermospheric models from density data obtained by assuming a fixed drag coefficient, independent of altitude. Because the uncertainty affecting the drag coefficient measurements was about 3% at both 200 km and 480 km of altitude, the calculated air density biases below 500 km were

  20. Self-reported sleep patterns, sleep problems, and behavioral problems among school children aged 8-11 years.

    PubMed

    Hoedlmoser, K; Kloesch, G; Wiater, A; Schabus, M

    2010-03-01

    OBJECTIVES: Investigation of sleep patterns, sleep problems, and behavioral problems in 8- to 11-year-old children. METHODS: A total of 330 children (age: M=9.52; SD=0.56; range=8-11 years; 47.3% girls) in the 4th grade of elementary school in Salzburg (Austria) completed a self-report questionnaire (80 items) to survey sleep patterns, sleep problems, and behavioral problems. RESULTS: Children aged 8-11 years slept approximately 10 h and 13 min on school days (SD=47 min) as well as on weekends (SD=81 min); girls slept significantly longer on weekends than boys. Most common self-reported sleep problems were dryness of the mouth (26.6%), sleep onset delay (21.9%), bedtime resistance (20.3%), and restless legs (19.4%). There was a significant association between watching TV as well as playing computer games prior to sleep with frightful dreams. Daytime sleepiness indicated by difficulty waking up (33.4%) and having a hard time getting out of bed (28.5%) was also very prominent. However, children in Salzburg seemed to be less tired during school (6.6%) or when doing homework (4.8%) compared to other nationalities. Behavioral problems (e.g., emotional symptoms, hyperactivity and inattention, conduct problems, peer problems) and daytime sleepiness were both significantly associated with sleep problems: the more sleep problems reported, the worse behavioral problems and daytime sleepiness were. Moreover, we could show that sharing the bed with a pet was also related to sleep problems. CONCLUSIONS: Self-reported sleep problems among 8- to 11-year-old children are very common. There is a strong relationship between sleep disorders and behavioral problems. Routine screening and diagnosis as well as treatment of sleep disorders in school children should, therefore, be established in the future. PMID:23162377