Solar Cycles

Differential absorption lidar (DIAL) at the National Institute for Environmental Studies (NIES) in Tsukuba (36 N, 140 E), Japan has been making routine observations for almost 20 years. Since 1988, more than 600 vertical profiles of stratospheric ozone and temperature have been obtained. We compared the lidar data with satellite data from the Stratospheric Aerosol and Gas Experiment (SAGE II) and assimilation data from the National Center for Environmental Prediction (NCEP). The lidar and SAGE II ozone profiles agreed within 5% in altitude range from 18 km to 40 km and within 10% up to 45 km. The lidar and NCEP temperatures agreed within 7 K in the 35-to 50-km range. Ozone levels were highest in spring at altitudes below 20 km. Above 30 km, the ozone maximum occurred during summer. The annual cycle of temperature is observed with a spring maximum for all altitudes in the 35-to 50-km range. Ozone variations caused by the quasi-biennial oscillation (QBO) and the 11-year solar cycle are discussed. The ozone trends after subtraction of the QBO and solar effects for the altitude range from 30 to 40 km are-6.0 AE 0.5%/decade for the period from 1988 to 1997 and statistically insignificant after 1998.

Of the ancient manuscripts that have survived to this day, the books from ancient Mexico (Mesoamerica), also called codices, belong to a very special group, namely those of picture writing. The Codex Borbonicus is a unique example of this preserved group of codices with picture writing. In addition to the complete depiction of the ritual 260 solar day almanac and the 365 solar day calendar with the 18 ritual agricultural holiday periods, this codex also has a complete 52 solar year cycle with both the year names and the 9 night deities. This combination does not appear in any of the other surviving codices.
In the literature, however, little attention is paid to this 52 solar year cycle, so important in ancient Mesoamerica before the Spanish invasion, which was closely intertwined with the Pleiades star group, which is said to have been closely watched at the close of each 52nd solar year. However, an extensive analysis shows that the 52 solar year cycle shown on pages 21 and 22 of the Codex Borbonicus contains a large number of errors, which are explained in detail in word and image in this paper.

During the studied period 1996-2007 I noticed that, the rising and oscillations of the sea level, global temperature, carbon dioxide concentration, ice mass of Antarctica, and melting of Greenland ice are highly correlated with Earth's orbital perturbations. Monthly variations of those parameters have two periodicities. Stronger one called “long-periodic cycle”, it is strongly related to solar activity. It appears as a rising trend during my studied period. Observation data of iceberg mass and its melting, global sea level, and concentration of greenhouse gases such as carbon dioxide is recent and does not cover a millennium or Wolf-Gleissberg solar cycle. So, it does not indicate a global warming. Second cycle is called “short-periodic cycle”. it is a weaker force but still stronger than human activities forcing. It appears as oscillations around the rising trend. The short periodic cycle of all mentioned parameters is found correlated to Earth's orbital perturbations which are indicating a global warming and global warming is a natural phenomenon. Global warming is strongly corelated to Sun, Earth’s orbit, and our  space.  I conclude that the productivity of natural greenhouse gases is greater than that produced by human activity. The current proposed global warming is not a result of human activities, rather just temporary epoch and natural phenomena. The Earth's orbital perturbations are in an excellent positive coherence with the Greenland ice mass but in a negative coherence with the Antarctic ice mass. My results are in good agreement with Yousef (2000) and Akasofu (2010).  I propose that the natural source of rising in concentration of greenhouse gases can be attributed to two causes: 1) Comets and asteroids, which are still carrying water molecules and some of greenhouse gas’ molecules to the Earth’s atmosphere; 2) Solar wind, which is composed greenhouse gases in ionization state. It may react and recombined though upper atmosphere before arriving to atmospheric lower levels at poles by unknown process. The global temperature is found to be correlated to Earth’s orbital perturbation too. This is because the declination angle is varying through the year. Output solar energy that arrives to the Earth depends on Sun-Earth distance too.

This second part of a two-paper series compares deterministic precipitation forecasts from the Storm-Scale Ensemble Forecast System (4-km grid) run during the 2008 NOAA Hazardous Weather Testbed (HWT) Spring Experiment, and from the Canadian Global Environmental Multiscale (GEM) model (15 km), in terms of their ability to reproduce the average diurnal cycle of precipitation during spring 2008. Moreover, radar-based nowcasts generated with the McGill Algorithm for Precipitation Nowcasting Using Semi-Lagrangian Extrapolation (MAPLE) are analyzed to quantify the portion of the diurnal cycle explained by the motion of precipitation systems, and to evaluate the potential of the NWP models for very short-term forecasting.

Ionospheric total electron content (TEC) of the equatorial ionization anomaly (EIA) is studied by analyzing dual-frequency signals of the Global Position System (GPS) acquired from a network of receivers around the Asian-Australian region during 1996-2004. The latitude, occurrence time, strength of the most developed EIA crest, and crest-to-trough ratio (CTR) for both the noon and post-sunset sector obtained from a daily TEC contour map have been used to study the solar cycle variations of EIA in the Asian-Australian region. The results reveal that semiannual and seasonal variations were the dominant factor that controls the morphology of the EIA structure which can be identified in the past studies (e.g. Wu et al., 2008). It is also found that the latitude and local time position of the anomaly crest show a hemispheric asymmetry because (a) The northern crest of EIA is expanded during the equinox indicating a weak semiannual variation while the southern crest is inhibited during June-August presenting a strong seasonal variation, and (b) The local time of the northern crest appears ~1.3 h earlier than that of the southern crest in June while showing no difference at December. Solar activity dependence is more evident in the EIA crest region than in the EIA trough region and least in the post-sunset sector at equinox. A seasonal linear relationship is derived between the post-sunset CTR and solar flux, which should be caused by the solar-dependant equatorial E×B vertical drift.

'Computational History' derives history from data and nowadays, therefore, relies on the technologies of the digital humanities. 'Computational History of Science' addresses questions of history by evaluating historical data, e.g. for tracing back copying traditions and conclude on transfer and transformation of data and knowledge. The term 'Applied Historical Astronomy', in contrast, tries to address questions of contemporary science by evaluating historical data in comparison with most recent data. This opens new possibilities, e.g. in the search for stellar transients among historical data.
In the contribution by Hoffmann & Vogt we will focus on the stellar transients among all the topics mentioned above. Philipp Protte discusses the accuracy of magnitudes and positions in ancient star catalogues, Andreas Schrimpf & Frank Verbunt present an analysis of an early modern star catalogue. Victor Reijs analyses the visibility of celestial objects for naked-eye observers, and Björn Kunzmann showcases some important variable stars in the history of astronomy. Rene Hudec presents astronomical photographic archives as a valuable data source for modern astrophysics. José M. Vaquero discusses the studies on solar observations made during the last four centuries. More technical are the contributions of Georg Zotti on 'Stellarium' and Karsten Markus-Schnabel on data-mining and data-processing technologies. Ido Yavetz & Luca Beisel are developing a digital tool of computational history of science for the simulation of pre-modern astronomical models. Gerd Graßhoff focuses more on the application of computational history with regard to Kepler's Astronomia Nova while Tim Karberg presents an analysis of the astronomical orientation of buildings in the North Sudan.

Wolfschmidt, Gudrun & Susanne M. Hoffmann (ed.):
Applied and Computational Historical Astronomy.
Angewandte und computergestützte historische Astronomie. Proceedings of the Splinter Meeting in the Astronomische Gesellschaft, Sept. 25, 2020. Hamburg: tredition (Nuncius Hamburgensis - Beiträge zur Geschichte der Naturwissenschaften; Bd. 55) 2021.
ISBN 978-3-347-27104-3 (Paperback), 978-3-347-27105-0 (Hardcover), 978-3-347-27106-7 (e-Book), (344 pages, 108 pages in colour). ISBN 978-3-949060-02-1 (computational Book), ©OpenScienceTechnology GmbH Berlin.

Ionospheric total electron content (TEC) of the equatorial ionization anomaly (EIA) is studied by analyzing dual-frequency signals of the Global Position System (GPS) acquired from a network of receivers around the Asian-Australian region during 1996-2004. The latitude, occurrence time, strength of the most developed EIA crest, and crest-to-trough ratio (CTR) for both the noon and post-sunset sector obtained from a daily TEC contour map have been used to study the solar cycle variations of EIA in the Asian-Australian region. The results reveal that semiannual and seasonal variations were the dominant factor that controls the morphology of the EIA structure which can be identified in the past studies (e.g. . It is also found that the latitude and local time position of the anomaly crest show a hemispheric asymmetry because (a) The northern crest of EIA is expanded during the equinox indicating a weak semiannual variation while the southern crest is inhibited during June-August presenting a strong seasonal variation, and (b) The local time of the northern crest appears ∼1.3 h earlier than that of the southern crest in June while showing no difference at December. Solar activity dependence is more evident in the EIA crest region than in the EIA trough region and least in the post-sunset sector at equinox. A seasonal linear relationship is derived between the post-sunset CTR and solar flux, which should be caused by the solar-dependant equatorial E×B vertical drift.

A B S T R A C T We analyzed 17 years (1993–2009) of horizontal winds measured by the medium frequency (MF) radar located at Tirunelveli (8.7°N, 77.8°E) and 10 years (2005–2014) of horizontal winds measured by a meteor radar located at Thumba (8.5°N, 77°E) to examine the seasonal, inter-annual, and solar cycle variability of the Quasi-Two Day Wave (QTDW) in the mesosphere and lower thermosphere region. These two radars are nearly co-located, but differ in their measurement technique. Comparison of the estimated QTDW amplitudes by the two radars shows that the amplitudes are larger in the meteor radar than those in the MF radar. The difference between the amplitudes is larger in May in the zonal component and in April and September in the meridional one. Furthermore, the differences are larger in the meridional component. The QTDWs in both the radars show a strong semi-annual oscillation (SAO). In addition, the meridional QTDW amplitudes of both the MF and meteor radars show a distinct enhancement in the month of October. While the whole spectra of QTDWs contribute to the SAO amplitudes, only 45–50 h waves contribute to the October enhancement. The amplitudes of the QTDWs, in general, show large inter-annual variability. The QTDW amplitudes from both the radars show modulation at period of quasi-biennial oscillation. The QTDWs of the MF radar show a small negative correlation with solar activity while those of meteor radar do not show any correlation. The above aspects are discussed in the light of current understanding of the QTDWs.

Tritium of the precipitation plays a very important role in the study of the waters of our planet because its tracer property is suitable for a better understanding of atmospheric and hydrological processes. Since the atmospheric test-ban treaty, the bomb tritium concentrations in precipitation have significantly reduced. Therefore, in the last two decades, global tritium concentration of precipitation (including anthropogenic and natural sources) have nearly reached a steady state level.
The aim of this study is to explore the variability of natural tritium in the past by using the neutron monitor time series, which represents the variability of solar activity. Many previous studies focused on the reconstruction of the bomb-tritium time series, taking into account the long tritium time series of some cities (Ottawa, Vienna, Tokyo). In our study, we primarily estimate the tritium of natural origin in the northern and southern hemispheres, which may be an important input parameter for atmospheric and hydrological modeling. Therefore, we been
have developed a statistical model to estimate short and long term changes in natural tritium. This estimate is based on the relationship between the global tritium time series and the neutron flux. The statistical model provides a relatively accurate estimate for stations that are poor in technogenic sources of tritium since time series values closely follow seasonal and long-term changes. Whereas for time series that are richer in technogenic tritium, the estimation is less accurate because the tritium values of the time series do not change regularly, that is, they do not follow the natural change.

By how much does the Sun's radiation vary? Although the Sun has long been an object of immense fascination, fundamental information about the magnitude and variability of its radiative output, sought for over a century, is only now approaching a level satisfactory for geophysical applications. During the past decade, satellite instruments have measured, simultaneously, both the Sun's spectrally integrated radiative output and its ultraviolet spectrum. These data have been analyzed in terms of their relationships to ground-based observations that characterize different aspects of the Sun's 11-year activity cycle, allowing estimates of solar radiative output variations over times scales from days to decades and interpretations of these variations in the broader context of the variable Sun. Uncertainties still remain to be answered by the next generation of solar radiometers, which commenced observations with the launch of the Upper Atmosphere Research Satellite in September 1991, near the maximum of solar cycle 22. radiator at-5770øK, is modulated by solar activity. The largest amplitude variations, reaching more than an order of magnitude, occur in the wings of the blackbody spectrum, at ultraviolet and radio wavelengths [White, 1977]; visible emissions near the peak of the blackbody curve are comparatively invariant. These visible emissions dominate the spectrally integrated (total) solar irradiance (historically misnamed the "solar constant"), which varied by-0.1% from the maximum to the minimum of solar cycle 21. Planetary atmospheres, comets, and the local interplanetary medium scatter, absorb, and reemit solar radiation at many different wavelengths, depending on their compositions [e.g., Chamberlain, 1978]. Variations in solar radiative output are therefore expected to cause changes in the chemistry, dynamics, and radiative properties of solar system bodies. Because the Sun is the This paper is not subject to U.S. copyright.

In this paper, we present an overview of radio signatures of sunspot NOAA 12192 measured with various instruments with frequencies of 37 GHz, 11.2 GHz and 200 - 400 MHz at Aalto University Metsahovi Radio Observatory (MRO). The data were observed during October 20 - 29, 2014. In total, 12 solar radio bursts at 11.2 GHz and 8 at 200 - 400 MHz, with varying intensities and properties, were observed. Radio brightening was captured in several solar radio maps. NOAA 12192 is the largest observed sunspot during solar cycle 24. We show that this exceptional radio brightening belongs to the strongest category including less than 5% of radio brightenings ever measured at MRO.

Sunspots provide total solar irradiance (TSI) proxy records for the last 310 years. Speleothem achieves are still
only of TSI proxy record providers, which allow extending of the TSI experimental records back to the pre- instrumental
times. Therefore they are very important for the assessment of the solar forcing of the climate in the pre-industrial era.
Using such speleothem records we demonstrated that variations of the solar irradiation which can produce climatic
variations are: (i) powerful prolonged solar cycles, which affect climatic variations and (ii) amplification of solar
irradiance impact on climate by different potential non-linear mechanism or by a combination of them. Such
amplification is important at durations shorter than 11 years but can be more significant in timescales less than 1 year.

This paper presents the development of a model to predict solar cycle (SC) 24 using the technique of neural networks (NNs). The model is provided with the time input parameters defining the year and the month of a particular SC, in order to characterise the temporal behaviour of sunspots as observed in the last 10 SCs. Geomagnetic activity measured by the aa index is also introduced as an input to the NN model in such a way that the model establishes the relationship between the aa index in the previous SC with the sunspot number (SSN) of the following SC. Assuming January 2008 as the minimum for SC 24, the shape and amplitude of SC 24 is estimated in terms of monthly mean and smoothed monthly SSN. This new prediction model estimates an average SC 24, with the maximum occurring around June 2012 [AE10 months] with a smoothed monthly maximum SSN of 117:5 AE 8:5.

The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

Solar spectral fluxes (or irradiance) measured by the SOlar Radiation and Climate Experiment (SORCE) show different variability at ultraviolet (UV) wavelengths compared to other irradiance measurements and models (e.g. NRL-SSI, SATIRE-S). Some modelling studies have suggested that stratospheric/lower mesospheric O 3 changes during solar cycle 23 (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008) can only be reproduced if SORCE solar fluxes are used. We have used a 3-D chemical transport model (CTM), forced by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), to simulate middle atmospheric O 3 using three different solar flux data sets (SORCE, NRL-SSI and SATIRE-S). Simulated O 3 changes are compared with Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite data. Modelled O 3 anomalies from all solar flux data sets show good agreement with the observations, despite the different flux variations. The off-line CTM reproduces these changes through dynamical information contained in the analyses. A notable feature during this period is a robust positive solar signal in the tropical middle stratosphere, which is due to realistic dynamical changes in our simulations. Ozone changes in the lower mesosphere cannot be used to discriminate between solar flux data sets due to large uncertainties and the short time span of the observations. Overall this study suggests that, in a CTM, the UV variations detected by SORCE are not necessary to reproduce observed stratospheric O 3 changes during 2001-2010.

A three-component model of the solar chromosphere, developed from ground based observations of the Ca II K chromospheric emission, is used to calculate the variability of the Lyman alpha flux between 1969 and 1980. The Lyman alpha flux at solar minimum is required in the model and is taken as 2.32 x 10 TM photons/cm2/s. This value occurred during 1975 as well as in 1976 near the commencement of solar cycle 21. The model predicts that the Lyman alpha flux increases to as much as 5 x 10 TM photons/cm2/s at the maximum of the solar cycle. The ratio of the average fluxes for December 1979 (cycle maximum) and July 1976 (cycle minimum) is 1.9. During solar maximum the 27-day solar rotation is shown to cause the Lyman alpha flux to vary by as much as 40% or as little as 5ø/,,. The model also shows that the Lyman alpha flux varies over intermediate time periods of 2 to 3 years, as well as over the l 1-year sunspot cycle. We conclude that, unlike the sunspot number and the 10.7-cm radio flux, the Lyman alpha flux had a variability that was approximately the same during each of the past three cycles. Lyman alpha fluxes calculated by the model are consistent with measurements of the Lyman alpha flux made by 11 of a total of 14 rocket experiments conducted during the period 1969-1980. The model explains satisfactorily the absolute magnitude, long-term trends, and the cycle variability seen in the Lyman alpha irradiances by the OSO 5 satellite experiment. The 27-day variability observed by the AE-E satellite experiment is well reproduced. However, the magnitude of the AE-E Lyman alpha irradiances are higher than the model calculations by between 40% and 80%. We suggest that the assumed calibration of the AE-E irradiances is in error. 1. [NTRODUCTION [1981] suggest a factor of 1.5. In addition, it has been suggested that the minimum Lyman alpha emission occurred in April 1975, 14 months prior to the beginning of solar cycle 21, as Copyright 1983 by the American Geophysical Union. Paper number 3A0619. 0148-0227/83/003A-0619505.00 defined by the minimum in the smoothed Zurich sunspot number [Vidal-Madjar and Phissarnay, 1980; Hinteregger et al., 1981]. Attempts to understand and quantify the variability of Lyman alpha emission have produced empirical models in which the Lyman alpha flux is parameterized as a linear function of either the sunspot number Rz [Cook et al., 1980; Vidal-Madjar, 1977] or the 10.7-cm radio emission F•0.?, [Bossy and Nicolet, 1981; Vidal-Madjar, 1977]. It may be, however, that by requiring the Lyman alpha emission to be linearly related to solar indices whose signatures originate at different levels in the solar atmosphere and which respond in different ways to solar magnetic activity, the issue of Lyman alpha flux variability has been made even more confusing. Lyman alpha emission originates in the solar chromosphere. The core of the line is formed at temperatures near

1] This study documents decadal-scale changes in the Holton and Tan (HT) relationship, i.e., the influence of the lower stratospheric equatorial quasi-biennial oscillation (QBO) on the northern hemisphere (NH) extratropical circulation. Using a combination of ECMWF ERA-40 Reanalysis and Operational data from 1958-2006, we find that the Arctic stratosphere is indeed warmer under easterly QBO and colder under westerly QBO. During November to January, composite easterly minus westerly QBO signals in zonal wind extend from the lower stratosphere to the upper stratosphere and are centered at $5 hPa, 55-65°N with a magnitude of $10 m s À1 . In temperature, the maximum signal is near $20-30 hPa at the pole with a magnitude of $4 K. During winter, the dominant feature is a poleward and downward transfer of wind and temperature anomalies from the midlatitude upper stratosphere to the high latitude lower stratosphere. For the first time, a statistically significant decadal scale change of the HT relationship during 1977-1997 is diagnosed. The main feature of the change is that the extratropical QBO signals reverse sign in late winter, resulting in fewer and delayed major stratospheric sudden warmings (SSWs), which occurred more often under westerly QBO. Consistent with earlier studies, it is found that the HT relationship is significantly stronger under solar minima overall, but the solar cycle does not appear to be the primary cause for the detected decadal-scale change. Possible mechanisms related to changes in planetary wave forcing are discussed. Citation: Lu, H., M. P. Baldwin, L. J. Gray, and M. J. Jarvis (2008), Decadal-scale changes in the effect of the QBO on the northern stratospheric polar vortex,

In this paper, climatological features of the polar F2-region electron density (N e) are investigated by means of statistical analysis using long-term observations from the European Incoherent Scatter UHF radar (called EISCAT in the following) and the EISCAT Svalbard radar (ESR) during periods of quiet to moderate geomagnetic activity. Fieldaligned measurements by the EISCAT and ESR radars operating in CP-1 and CP-2 modes are used in this study, covering the years 1988-1999 for EISCAT and 1999-2003 for ESR. The data are sorted by season (equinox, summer and winter) and solar cycle phase (maximum, minimum, rising and falling). Some novel and interesting results are presented as follows: (1) The well-known winter anomaly is evident during the solar maximum at EISCAT, but it dies out at the latitude of the ESR; (2) The daytime peaks of N e at EISCAT for all seasons during solar maximum lag about 1-2 h behind those at ESR, with altitudes about 10-30 km lower. (3) In addition to the daytime peak, it is revealed that there is another peak just before magnetic midnight at ESR around solar maximum, especially in winter and at equinox. The daytime ionization peak around magnetic noon observed by ESR can be attributed to soft particle precipitation in the cusp region, whereas the pre-midnight N e maximum seems likely to be closely related to substorm events which frequently break out during that time sector, in particular for the winter case. (4) Semiannual variations are found at EISCAT during solar minimum and the falling phase of the solar cycle; at the rising phase, however, the EISCAT observations show no obvious seasonal variations.

This study presents the continuous GPS network in Vietnam and the results of study on time variations of the total electron content (TEC) in the South East Asian equatorial ionization anomaly (EIA) for the 2006-2013 period. In each year we observe a semiannual pattern of amplitude of the EIA crests with its maximum amplitude at equinox. In both hemispheres, the amplitude of the crest is larger in northern spring equinox than in autumn from 2006 to 2008 (descending phase of solar cycle) and smaller in spring than in autumn from 2009 to 2011 (increasing phase of solar cycle), from 2012-2013 (maximum period of solar cycle) the amplitudes of the crests in spring and autumn are equivalent. We also observe an asymmetry between the amplitude and the position of the two crests of ionization. There is a very high level of correlation between the amplitude of the TEC at the two crests and the sunspot number is approximately equal to 0.9. During the deep solar minimum 2008-2009, the amplitude of crests of ionization becomes small during several months in summer and winter (about 20 TECu). The results show that both crests move more significantly equatorward in winter than in other seasons and there is a tendency for both crests to appear earlier in winter and later in summer. In the solar minimum years, the amplitudes of the crests are minimal; the positions of the crests are nearer the magnetic equator and the crests appear earlier than in other years.

The Late Miocene paleogeography of central Europe and its climatic history are well studied with a resolution of c. 10(6) years. Small-scale climatic variations are yet unresolved. Observing past climatic change of short periods, however, would encourage the understanding of the modern climatic system. Therefore, past climate archives require a resolution on a decadal to millennial scale. To detect such a short-term evolution, a continuous 6-m-core of the Paleo-Lake Pannon was analyzed in 1-cm-sample distance to provide information as precise and regular as possible. Measurements of the natural gamma radiation and magnetic susceptibility combined with the total abundance of ostracod shells were used as proxies to estimate millennial- to centennial scale environmental changes during the mid-Tortonian warm period. Patterns emerged, but no indisputable age model can be provided for the core, due to the lack of paleomagnetic reversals and the lack of minerals suitable for absolute datin...

This paper presents the development of a model to predict solar cycle (SC) 24 using the technique of neural networks (NNs). The model is provided with the time input parameters defining the year and the month of a particular SC, in order to characterise the temporal ...

We study the sunspot activity in relation to spotless days (SLDs) during the descending phase of solar cycles 11-24 to predict the amplitude of sunspot cycle 25. For this purpose, in addition to SLD, we also consider the geomagnetic activity (aa index) during the descending phase of a given cycle. A very strong correlation of the SLD (0.68) and aa index (0.86) during the descending phase of a given cycle with the maximum amplitude of next solar cycle has been estimated. The empirical relationship led us to deduce the amplitude of cycle 25 to be 99.13± 14.97 and 104.23± 17.35 using SLD and aa index, respectively as predictors. Both the predictors provide comparable amplitude for solar cycle 25 and reveal that solar cycle 25 will be weaker than cycle 24. Further, we predict that the maximum of cycle 25 is likely to occur between February and March 2024. While the aa index has been utilized extensively in the past, this work establishes SLDs as another potential candidate for predicting the characteristics of the next cycle.

A statistical study of the effects of the solar cycle, as indicated by the value of F10.7, has been made utilizing a data base of electrostatic shocks and the associated ion beams, ion conics, and electron distributions obtained by the S3-3 satellite during the rising phase of the solar cycle. Ion composition was not included since the ion detectors utilized for this study did not determine mass. The acceleration of ions in association with electrostatic shocks is strongly dependent on F10.7 at altitudes of-2000 -8000 km. For low F10.7 (<80), -43% of the shocks were associated with conics and -43% with beams, whereas for high F10.7 (100-225), -18% of the shocks were associated with beams and -64% with conics. This difference was observed for essentially all magnetic local times and altitudes except the period from 0000 -0600 MLT. These results suggest that parallel potential drops are less common at altitudes below 8000 km during solar maximum than during solar minimum. However, for the events where ion beams were observed, the average parallel potential drop below the satellite (as determined from the peak ion energy) had very similar values, and approximately half of the potential occurred below the satellite altitude for both high and low F10.7.

For a given galactic cosmic ray (GCR) environment, understanding the distribution of the particle flux (protons, alpha particles, and heavy ions) in deep-space and on the surface of planetary systems such as Mars are essential for the risk assessment of future human exploration missions. In our model calculations, we make use of the NASA's HZETRN (High Z and Energy Transport) code along with the nuclear fragmentation cross sections that are described by the quantum multiple scattering (QMSFRG) model with the time-dependant variation of the GCR environment derived making use of the solar modulation potential, phi. Data from the cosmic ray isotope spectrometer (CRIS) instrument onboard the advanced composition explorer (ACE) has been available from 1998. Data from the CRIS instrument is being analyzed to understand the short term variations in the particle spectrum during the current solar cycle phase. In this report, particle spectrum for December 2002 of the CRIS instrument was compared with the model calculations. Current assessment of the model calculations show very good agreement of the particle flux (∼ 15% for low Z and ∼ 5% for high Z) data from Boron (Z = 5) through Nickel (Z = 28) nuclei for the energy bins reported by CRIS. Similarly, the model calculated dose-rate calculations are compared with the proton flux measured dose-rate from the Martian Radiation Environment Experiment (MARIE) currently onboard the 2001 Mars Odyssey spacecraft in Martian orbit for the month of August 2003 that is representative of a quiet-time GCR data at Mars. Current model calculations are well within 10% of the measured observations of MARIE. The predictive capabilities of the quiet-time GCR particle flux model calculations are promising for biological and shielding studies and for the radiation risk assessment for future human explorations.

Two temperature datasets are analyzed for quantifying the 11-year solar cycle effect in the lower stratosphere. The analysis is based on a regression linear model that takes into account volcanic, Arctic Oscillation (AO), Quasi-Biennial Oscillation (QBO) and El Nino Southern Oscillation (ENSO) effects. Under solar maximum conditions, temperatures are generally warmer for low-and mid-latitudes than under solar minimum, with the effect being the strongest in northern summer. At high latitudes, the vortex is generally stronger under solar maximum conditions, with the exception of February and to a lesser extent March in the Northern Hemisphere; associated with this positive signal at high latitudes, there is a significant negative signal at the equator. Observations also suggest that contrary to the beginning of the winter, in February-March, the residual circulation in the Northern Hemisphere is enhanced. A better understanding of the mechanisms at work comes from further investigations using the ERA-40 reanalysis dataset. First, a consistent response in terms of temperature and wind is obtained. Moreover, considering Eliassen-Palm (EP) flux divergence and residual circulation stream functions, we found an increased circulation in the Northern Hemisphere in February during solar maxima, which results in more adiabatic warming at high latitudes and more adiabatic cooling at low latitudes, thus demonstrating the dynamical origin of the response of the low stratosphere to the solar cycle.

1] In spite of many recent developments in observations and models of the solar corona, the exact form of the heating function of the solar wind plasma is unknown. Here we attempt to make some progress on that problem by applying a previously developed simplified magnetohydrodynamic model to a unique synthesis of remote sensing coronal observations from SOHO and Spartan 201, and in-situ data from Ulysses spacecraft during the quiescent phase of solar cycle 23 (1995)(1996)(1997) which also included the Whole Sun Month (August/September 1996) study period. Our analysis provides for the first time an empirically derived estimate of the heat flux and temperature profile of the corona and interplanetary medium over the solar polar regions as a function of latitude and radial distance for this data set. The latitudinal and radial variation is extended to include the equatorial regions but with less fidelity given the significant structure associated with the streamer belt. Our results suggest that both thermal and nonthermal heating terms contribute to the temperature and heat flux in the low corona, particularly above the poles, with the non-thermal component possibly providing as much as half of the total heat input.

In this paper we present an overview of solar radio observations at 11.2 GHz on Mets?hovi Radio Observatory (MRO). The data were observed during the solar cycles 23 and 24 (2001-2013) both in solar maxima and minimum. In total, 180 solar radio bursts, with varying intensities and properties, were observed. We compare our data series with other similar data sets. A good correlation can be found between the data series. It is concluded that one can conduct scientifically significant solar radio observations with a low cost instrument as the one presented in this paper.

Solar activities rule the earths climate change. There are dozens of natural forces and cycles that contribute to the earth's climate change. But the dominant force is the sun, and demonstrates itself in many different ways. The most basic and impactful is the 11-year solar magnetic cycle. But even these have their own variations and their own secondary cycles, including the 400-year Grand Solar Minimum and the Millennial cycle. Not only does it increase/increase the TSI send to earth, but empowers numerous other and seeming unrelated forces and events by modulating the galactic cosmic rays and volcanic activities. Even the famous Milankovitch cycles are little more than variations of how much power the sun delivers to the earth, and where and how.

This study explores the long-term frequency variability of high-surge events (HSEs) in the North Adriatic, the so-called acqua alta, which, particularly during autumn, cause flooding of the historical city center of Venice. The period 1948-2008, when hourly observations of sea level are available, is considered. The frequency of HSEs is correlated with the 11 year solar cycle, solar maxima being associated with a significant increase in the October-November-December HSE frequency. The seasonal geopotential height pattern at 1000 hPa (storm surge pattern; SSP) associated with the increased frequency of HSEs is identified for the whole time period and found to be similar to the positive phase of the main variability mode of the regional atmospheric circulation (empirical orthogonal function 1; EOF1). However, further analysis indicates that solar activity modulates the spatial patterns of the atmospheric circulation (EOF) and the favorable conditions for HSE occurrence (SSP). Under solar maxima, the occurrence of HSEs is enhanced by the main mode of regional atmospheric variability, namely, a large-scale wave train pattern that is symptomatic of storm track paths over northern Europe. Solar minima reveal a substantially different and less robust SSP, consisting of a meridionally oriented dipole with a preferred southward path of storm track activity, which is not associated with any dominant mode of atmospheric variability during low-solar periods. It is concluded that solar activity plays an indirect role in the frequency of HSEs by modulating the spatial patterns of the main modes of atmospheric regional variability, the favorable patterns for HSE occurrence, and their mutual relationships, so that constructive interaction between them is enhanced during solar maxima and inhibited in solar minima.

Power spectral analyses of the time series of solar proton events during the past three solar cycles reveal a periodicity around 154 days. This feature is prominent in all of the cycles combined, cycles 19 and 21 individually but is only weak in cycle 20. These results are consistent with the presence of similar periodicities between 152 and 155 days in the occurrence rate of major solar flares, the sunspot blocking function (P,), the 10.7 cm radio flux (F1o7) and the sunspot number (Rz). This suggests that the circa 154-days periodicity may be a fundamental characteristic of the Sun. Periods around 50-52 days are also found in the combined data set and in the three individual cycles in general agreement with the detection of this periodicity in major flares in cycle 19 and in P,, F1o.7, and R~ in cycle 21. The cause of the 155 day period remains unknown. The spectra contain lines (or show power at frequencies) consistent with a model in which the periodicity is caused by differential rotation of active zones and a model in which it is related to beat frequencies between solar oscillations, as proposed by Wolff.

Ozone profiles derived from ground-based Umkehr measurements at five stations and from the merged data set of Solar Backscattered Ultra Violet (SBUVv8) satellite observations are used to estimate the seasonal influence of the 11-year solar signal in the vertical distribution of stratospheric ozone. Both data sets show a strong response (2-3% of the annual mean) in the upper stratosphere, a very small response in the middle tropical stratosphere and a secondary maximum ($2%) in the tropical lower stratosphere, in accordance to earlier reports. Thus a sequence of high-low-high response is seen in the vertical pattern of the solar cycle effect on ozone in the tropics, with its position sensitive to season, as it appears to move across the equator in direction opposite to the location of the maximum solar insolation. Results from Umkehr and satellite observations are in good agreement at levels up to 35 km, while discrepancies (of up to 2%) found at higher levels (around 40 km) are largest in summer. Finally, the estimated erythemal irradiance response to the 11-year solar cycle, calculated for the observed ozone change during a solar cycle (minimum to maximum), showed an overall decrease in the irradiance at the surface which is maximum (À2% of annual mean) over the tropics.

The short-term relationship of the equatorial peak electron density and the solar shortwavelength irradiance is examined using foF2 observations from Jicamarca, Peru and recent solar irradiance measurements from satellites. Solar soft X-ray measurements from both the Student Nitric Oxide Explorer (SNOE) (1998-2000) and Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) (2002-2004) satellites as well as extreme ultraviolet (EUV) measurements from the TIMED satellite are used. Soft X-rays show similar or higher correlation with foF2 at short timescales (27 days or less) than EUV does, although the EUV correlation is higher for longer periods. For the short-term variations, both SNOE and TIMED observations have a higher correlation in the morning

This paper deals with two problems, methods of foF2 trend determination and origin of trends in foF2, both being controversial in current literature. We found that various regression-based methods and artificial neural networkbased method of Yue et al. (2006) provided comparable results within uncertainties caused mainly by various ways of removing/suppressing the dominant solar cycle effect. The role of geomagnetic activity in the observed trends in foF2 was probably substantial and might be still even rather dominant in the last quarter of the 20th century.

We present data on the solar irradiance as derived from a number of sources. An attempt was made to bring these data onto a uniform scale. The results are presented in table 5 and figure 6. Summation of fluxes at all wavelengths yields a figure of 1357.826 for the solar constant. Estimates are made of the solar flux variations due to flares, active regions (slowly varying component), 27-day period, and the 11-yr cycle. Solar activity does not produce a significant variation in the value of the solar constant. Nevertheless, variations in the X-ray and EUV portions of the solar flux may be several orders of magnitude during solar activity, especially at times of major flares. It is, of course, well established that these short wavelength flux enhancements cause significant changes in the terrestrial ionosphere. 60000. 80000 Mi]

In this study, we are investigating the solar flare events during each Carrington rotation in the period 2002-2017. We studied the relationship between solar flare event location and solar cycle progress (phases). The solar flare events are tending to accumulate around a specific latitude line in the southern and northern hemispheres of the solar disk, which we call the "eruptive latitude". The eruptive latitude is migrating towards the solar equator during the declining phase and away from the solar equator during the ascending phase. The eruptive latitude is consistent with the sunspot butterfly diagram. We found the suitable equation describing the relationship between the eruptive latitude ϕ and the Carrington rotation number CR using sinusoidal summation function.

Astronomers have observed sunspot cycles ever since 1600 with a period that varies from 10-12y and from no spots per day at the minima to over 300 spots per day at the maxima. Although there are a great number of analyses of sunspot activity, there has not as yet been an explanation for the periodicity of sunspot activity. However, the collapse of quantum aether that unites gravity and charge forces also results in a gravity vector force called quadrupole gravitization. Quadrupole gravitization couples star motion and is responsible for galaxy rotation and gravitization also affect the sun and other stars convection as well.

The matter decay and motion of our sun couples with the matter decays and motions of nearby binary stars, Procyon and 61-Cygni, which are both 11.4 light years (lyrs) away. This coupling results in a periodic change in solar convection that is the sunspot cycle. The proximity of these two binary stars along with the periods of these two binary stars correlate well with the period and variation of sunspot activity, both the variation of period and the variation of amplitude.

Notably, the Maunder minimum correlates well with the separation of the 61-Cygni binary star. The Maunder minimum was a notably lack of sunspots that lasted from about 1660 to 1700 and coincided with a period of lower temperatures on earth, the so-called little ice age.

This paper presents the development of a model to predict solar cycle (SC) 24 using the technique of neural networks (NNs). The model is provided with the time input parameters defining the year and the month of a particular SC, in order to characterise the temporal ...

The analysis of the f oF 2 ionosonde data acquired at mid and high latitudes reveals a general decreasing of the F2 plasma frequency over more than two solar cycles, showing steeper trends over the high latitude stations and, in particular, over Antarctica. A careful analysis of the f oF 2 hourly data, opportunely catalogued in different levels of magneto-ionospheric conditions, highlights the role of the geomagnetic activity in the secular change of the ionosphere and confirms the latitudinal dependence of the trends. These results suggest interesting relations with some recent findings on the rapid decrease of some important physical and statistical quantities related to the geomagnetic field over the whole globe and mainly in Antarctica. In this paper we discuss the possibility of a connection between the ionospheric trends and a possible imminent geomagnetic reversal or excursion.

Two temperature datasets are analyzed for quantifying the 11-year solar cycle effect in the lower stratosphere. The analysis is based on a regression linear model that takes into account volcanic, Arctic Oscillation (AO), Quasi-Biennial Oscillation (QBO) and El Nino Southern Oscillation (ENSO) effects. Under solar maximum conditions, temperatures are generally warmer for low-and mid-latitudes than under solar minimum, with the effect being the strongest in northern summer. At high latitudes, the vortex is generally stronger under solar maximum conditions, with the exception of February and to a lesser extent March in the Northern Hemisphere; associated with this positive signal at high latitudes, there is a significant negative signal at the equator. Observations also suggest that contrary to the beginning of the winter, in February-March, the residual circulation in the Northern Hemisphere is enhanced. A better understanding of the mechanisms at work comes from further investigations using the ERA-40 reanalysis dataset. First, a consistent response in terms of temperature and wind is obtained. Moreover, considering Eliassen-Palm (EP) flux divergence and residual circulation stream functions, we found an increased circulation in the Northern Hemisphere in February during solar maxima, which results in more adiabatic warming at high latitudes and more adiabatic cooling at low latitudes, thus demonstrating the dynamical origin of the response of the low stratosphere to the solar cycle.

It is generally accepted that small-scale gravity waves (GW) produce the observed reversals in the zonal circulation and temperature variations of the upper mesosphere (e.g., Lindzen, 1981). There is evidence that GW also play an important role in the quasi-biennial oscillation (QBO) of the lower stratosphere, which can be generated by planetary waves (Lindzen and Holton, 1968). In the present paper, we summarize the modeling studies with the mechanistic numerical spectral model (NSM), which incorporates the Doppler spread parameterization for GW (Hines, 1997a, b). Our studies illuminate the importance of GW filtering and momentum deposition associated with critical level absorption and wave braking. Numerical results from the 2D and 3D versions of the NSM show how these wave interactions generate in the zonal-mean: (a) annual and semi-annual oscillations, (b) QBO with related semi-decadal oscillation and solar cycle effects, and (c) monthly intra-seasonal oscillations.

The historical Hungarian auroral record extends from 1523 to 1960 and is longer than the sunspot record. Harmonic analysis reveals four major multidecadal secular cycles forming an approximate harmonic set at periods of 42.85, 57.13, 85.7 and 171.4 years. These four frequencies are very close to the four major heliospheric oscillations relative to the center of mass of the solar system caused by Jupiter, Saturn, Uranus and Neptune. Similar frequencies are found in solar radiation models based on long cosmogenic isotope records (Steinhilber et al. 2012) and in long records of naked-eye sunspot observations (Vaquero et al., 2002). Harmonic regression models are used to reconstruct and forecast aurora and solar activity for the period 1956-2050. The model predicts: (1) the multidecadal solar minimum in the 1970s that is also observed in the sunspot record; (2) a solar maximum in 2000-2002 that is observed in the ACRIM total solar irradiance satellite composite; (3) a prolonged solar minimum centered in the 2030s. These findings support a hypothesis that the Sun, the heliosphere and the terrestrial magnetosphere are partially modulated by planetary gravitational and magnetic forces synchronized to planetary oscillations, as also found in other recent publications (Scafetta,

Tremendous amount of solar energy is hurled into the space by transient sporadic emissions occurring within the Sun. A fraction of this energy is transferred into the Earth's magnetosphere by the magnetic reconnection process. Interplanetary magnetic field plays a crucial role in the excitation of geomagnetic storms and their subsequent evolution. The present study attempts to determine the influence of postshock duration of southward B z on the development and intensification of intense (Dst r À200 nT) geomagnetic storms. The study presents 18 big storm events that occurred during the solar cycle 23. In all the cases under study, the interplanetary shocks were driven by the interplanetary coronal mass ejections (ICMEs). The ICME structures may contain southward magnetic fields within the sheath, the magnetic cloud or both in succession, which can lead to the development of intense geomagnetic storms. In addition, dependence of storm strength on the total energy influx into the magnetosphere (E) and ring current (E RC ) energy is also assessed. Geomagnetic storm characteristics are examined at a lowlatitude station, Alibag (geographic lat. 18:63 3 N, long. 72:87 3 E; geomagnetic lat. 10:02 3 N, long. 145:97 3 ), using high resolution digital data. The minimum duration of southward B z for strengthening the storms is $ 1:25 h. All intense storms are found to have minimum values of southward directed B z to be r À18 nT and interplanetary electric field E y 4 12 mV=m. Intensity of geomagnetic storms at lowlatitudes follows a fairly linear dependence on the ring current energy.

The study of climate is one of the most complex and most multidisciplinary areas of research known to science. Models are used, which are mathematical representations of forcings, interactions and feedbacks of all the variables that affect climate. Most models are driven by atmospheric physics and play an important role in our understanding of the Earth's climate and how it will likely change in the future. An extensive review of the scientific literature reveals a striking simplification of solar output and its impact on climate. The well-known 11-year cycles are represented but there is no representation of longer cycles such as the Gleissberg 88-year cycle and the Devries 208-year cycle. The reason for the omission is most likely the fact that multi-decadal solar cycles are poorly understood as to their occurrence, strength and periodicity. Nonetheless, the longer cyclicalities appear to be present in the observed temperatures. The absence of important forcing factors from the models has led to a theory that is fundamentally underdetermined. There are fewer interactions and feedbacks in the models and too many unknown variables and degrees of freedom. An underdetermined system typically has many solutions. In other words, there can be other theories that are compatible with the same set of observations. This study presents a reduced model of six elements of natural variability that are not currently included in the models: four solar decadal cycles and two decadal oceanic oscillations. Monte-Carlo simulations are performed on the six stochastic natural variables and are shown to produce patterns similar to the observed patterns published in the literature.

It is well known that there are profound effects of solar cycle (SC) on the tropical deep convection and hence the atmospheric circulations. However, it is unknown how the intensity and duration of SC is going to affect the circulation patterns. In the present study, the effect of SC on the Hadley circulation (HC) is investigated based on intensity and duration of the SC using ERA-Interim dataset obtained during 1979-2012. Maximum and minimum SC is differentiated based on sunspot number (SSN) with cutoff at >=100 and <=20 for solar maximum and minimum, respectively. The duration of solar maximum (minimum) and its peak intensity are found decreasing (increasing) from SC 21 to SC 23. During solar maximum, convection shifts southward over South Ameri-can and African (10oS) sectors and no convection over Indian and adjoining sectors. This feature, however, varies from cycle to cycle. It is found that SC with larger intensity causes the convection centres to shift to Pacific i.e. zonally (EW) and longer duration in SC causes the convective centres to shift to southward i.e. meridionally (NS). Mass stream function analysis reveals that the HC decreased in SC 22 compared to SC 21 and SC 23 against increase or no change in the pacific region. This is attributed to the persistence of high sunspot activity for a larger period. HC is relatively strong in SC 21suggesting the influence of solar activity is relatively more in SC 21 compared to SC 23. Even though the duration of SC 23 is more (12.6 years), the SSN is less (120.8) compared to the SC 21 (10.9 years with peak SSN 164). This strong and less period of solar activity might be the reason for relatively strong influence of solar activity on SC 21 compared to SC 23. In addition, the spotless days are very less during SC 21 (273 days) compared to SC 23 (821 days). Thus, it is observed that Southern Hemisphere HC is strongly influenced (reduced) during solar maximum which depends further on the duration and intensity. Less duration causes more influence on HC.