Empirical Modelling of Solar Energetic Particles
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Properties of the Solar Velocity Field Indicated by Motions of Sunspot Groups and Coronal Bright Points
DISSERTATION zur Erlangung des Doktorgrades an der Naturwissenschaflichen Fakultät der Karl-Franzens-Universität Graz Properties of the solar velocity field indicated by motions of sunspot groups and coronal bright points Ivana Poljančić Beljan begutachtet von Univ.-Prof. Dr. Arnold Hanslmeier Institut für Physik Karl-Franzens-Universität Graz und Dr. Roman Brajša, scientific advisor Hvar Observatory, Faculty of Geodesy University of Zagreb 2018 Thesis advisor: Univ.-Prof. Dr. Hanslmeier Arnold Ivana Poljančić Beljan Properties of the solar velocity field indicated by motions of sunspot groups and coronal bright points Abstract The solar dynamo is a consequence of the interaction of the solar magnetic field with the large scale plasma motions, namely differential rotation and meridional flows. The main aims of the dissertation are to present precise measurements of the solar differential rotation, to improve insights in the relationship between the solar rotation and activity, to clarify the cause of the existence of a whole range of different results obtained for meridional flows and to clarify that the observed transfer of the angular momentum to- wards the solar equator mainly depends on horizontal Reynolds stress. For each of the mentioned topics positions of sunspot groups and coronal bright points (CBPs) from five different sources have been used. Synodic angular rotation velocities have been calculated using the daily shift or linear least-square fit methods. After the conversion to sidereal values, differential rotation profiles have been calculated by the least-square fitting. Covariance of the calculated rotational and meridional velocities was used to de- rive the horizontal Reynolds stress. The analysis of the differential rotation in general has shown that Kanzelhöhe Observatory for Solar and Environmental research (KSO) provides a valuable data set with a satisfactory accuracy suitable for the investigation of differential rotation and similar studies. -
Fossil Fuels
Gonzaga Debate Institute 1 Warming Core Warming Bad Gonzaga Debate Institute 2 Warming Core ***Science Debate*** Gonzaga Debate Institute 3 Warming Core Warming Real – Generic Warming real - consensus Brooks 12 - Staff writer, KQED news (Jon, staff writer, KQED news, citing Craig Miller, environmental scientist, 5/3/12, "Is Climate Change Real? For the Thousandth Time, Yes," KQED News, http://blogs.kqed.org/newsfix/2012/05/03/is- climate-change-real-for-the-thousandth-time-yes/) BROOKS: So what are the organizations that say climate change is real? MILLER: Virtually ever major, credible scientific organization in the world. It’s not just the UN’s Intergovernmental Panel on Climate Change. Organizations like the National Academy of Sciences, the American Geophysical Union, the American Association for the Advancement of Science. And that's echoed in most countries around the world. All of the most credible, most prestigious scientific organizations accept the fundamental findings of the IPCC. The last comprehensive report from the IPCC, based on research, came out in 2007. And at that time, they said in this report, which is known as AR-4, that there is "very high confidence" that the net effect of human activities since 1750 has been one of warming. Scientists are very careful, unusually careful, about how they put things. But then they say "very likely," or "very high confidence," they’re talking 90%. BROOKS: So it’s not 100%? MILLER: In the realm of science; there’s virtually never 100% certainty about anything. You know, as someone once pointed out, gravity is a theory. BROOKS: Gravity is testable, though.. -
Zonal Harmonics of Solar Magnetic Field for Solar Cycle Forecast
Zonal harmonics of solar magnetic field for solar cycle forecast VN Obridkoa,e, DD Sokoloffa,c,d, VV Pipinb, AS Shibalovaa,c,d, IM Livshitsa aIzmiran, Kaluzhskoe Sh., 4, Troitsk, Moscow, 108840, Russia bInstitute of Solar-Terrestrial Physics, Russian Academy of Sciences, Irkutsk, 664033, Russia cDepartment of Physics, Moscow State University, 19991, Russia dMoscow Center of Fundamental and Applied Mathematics, Moscow, 119991, Russia eCentral Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, St. Petersburg Abstract According to the scheme of action of the solar dynamo, the poloidal magnetic field can be considered a source of production of the toroidal magnetic field by the solar differential rotation. From the polar magnetic field proxies, it is natural to expect that solar Cycle 25 will be weak as recorded in sunspot data. We suggest that there are parameters of the zonal harmonics of the solar surface magnetic field, such as the magnitude of the l = 3 harmonic or the effective multipole index, that can be used as a reasonable addition to the polar magnetic field proxies. We discuss also some specific features of solar activity indices in Cycles 23 and 24. Keywords: Sun: magnetic fields, Sun: oscillations, sunspots 1. Introduction The problem of forecasting solar activity is a long-lasting one. Actually, this problem occurred as soon as the solar cycle was discovered, but we are still far from its definite solution. Before each sunspot maximum, forecasts of the cycle amplitude appear, but the predicted values are in quite a wide range (Obridko, 1995; Lantos and Richard, 1998). The past two Cycles, 23 and 24, were no exception. -
Statistical Study of Solar Activity Parameters of Solar Cycle 24
Volume 65, Issue 1, 2021 Journal of Scientific Research Institute of Science, Banaras Hindu University, Varanasi, India. Statistical Study of Solar Activity Parameters of Solar Cycle 24 Abha Singh1 and Kalpana Patel*2 1Department of Physics, T.D.P.G. College, Jaunpur-222002, U.P., India. [email protected] 2Department of Physics, SRM Institute of Science and Technology, Delhi-NCR Campus, Delhi-Meerut Road, Modinagar-201204, U.P. India. [email protected]* Abstract: The solar atmosphere is one of the most dynamic smoothed sunspot numbers that was brought into existence with environments studied in modern astrophysics. The term solar its classification (Kunzel, 1961). The number predicts short term activity refers to physical phenomena occurring within the periodic high and low activity of the Sun. The part of the cycle magnetically heated outer atmosphere of the Sun at various time with low sunspot activity is referred to as "solar minimum" scales. S un spots, high-speed solar wind, solar flares and coronal while region with maximum solar activity is called as "solar mass ejections are the basic parameters that govern maximum”. Hathaway et al. (2002) examined the ‘group’ solar activity. All solar activity is driven by the solar magnetic field. The present paper studies the relation between various solar sunspot number which shows it use in featuring the Sun’s features during solar cycle 24. The study reveals that there exists a performance during the solar year (Hoyt & Schatten, 1998a). good correlation between various parameters. This indicates that they all belong to same origin i.e., the variability of Sun’s magnetic Coronal mass ejections (CMEs) are the explosions in the solar 42field. -
Effects of Version 2 of the International Sunspot Number on Naïve
https://ntrs.nasa.gov/search.jsp?R=20190001636 2019-08-30T11:15:09+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server Space Weather RESEARCH ARTICLE Effects of Version 2 of the International Sunspot Number on 10.1029/2018SW002080 Naïve Predictions of Solar Cycle 25 Key Points: • A new calibration of sunspot W. Dean Pesnell1 number must be used in solar cycle predictions 1Solar Physics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD, USA • The climatological average is used to assess other predictions • Other simple predictions are not very accurate or useful Abstract The recalibration of the International Sunspot Number brings new challenges to predictions of Solar Cycle 25. One is that the list of extrema for the original series is no longer usable because the values of all maxima and minima are different for the new version of the sunspot number. Timings of extrema are Correspondence to: W. D. Pesnell, less sensitive to the recalibration but are a natural result of the calculation. Predictions of Solar Cycle 25 [email protected] published before 2016 must be converted to the new version of the sunspot number. Any prediction method that looks across the entire time span will have to be reconsidered because values in the nineteenth Citation: century were corrected by a larger factor than those in the twentieth century. We report a list of solar Pesnell, W. D. (2018). Effects of maxima and minima values and timings based on the recalibrated sunspot number. -
Nonaxisymmetric Component of Solar Activity and the Gnevyshev-Ohl Rule
Solar Physics DOI: 10.1007/•••••-•••-•••-••••-• Nonaxisymmetric Component of Solar Activity and the Gnevyshev-Ohl rule E.S.Vernova1 · M.I. Tyasto1 · D.G. Baranov2 · O.A. Danilova1 c Springer •••• Abstract The vector representation of sunspots is used to study the non- axisymmetric features of the solar activity distribution (sunspot data from Greenwich–USAF/NOAA, 1874–2016).The vector of the longitudinal asym- metry is defined for each Carrington rotation; its modulus characterizes the magnitude of the asymmetry, while its phase points to the active longitude. These characteristics are to a large extent free from the influence of a stochastic component and emphasize the deviations from the axisymmetry. For the sunspot area, the modulus of the vector of the longitudinal asymmetry changes with the 11-year period; however, in contrast to the solar activity, the amplitudes of the asymmetry cycles obey a special scheme. Each pair of cycles from 12 to 23 follows in turn the Gnevyshev–Ohl rule (an even solar cycle is lower than the following odd cycle) or the “anti-Gnevyshev–Ohl rule” (an odd solar cycle is lower than the preceding even cycle). This effect is observed in the longitudinal asymmetry of the whole disk and the southern hemisphere. Possibly, this effect is a manifes- tation of the 44-year structure in the activity of the Sun. Northern hemisphere follows the Gnevyshev–Ohl rule in Solar Cycles 12–17, while in Cycles 18–23 the anti-rule is observed. Phase of the longitudinal asymmetry vector points to the dominating (active) longitude. Distribution of the phase over the longitude was studied for two periods of the solar cycle, ascent-maximum and descent-minimum, separately. -
Arxiv:2005.12166V1 [Astro-Ph.SR] 25 May 2020
Draft version May 26, 2020 Typeset using LATEX modern style in AASTeX63 A model-free, data-based forecast for sunspot cycle 25 Aleix Espua-Fontcuberta,1 Saikat Chatterjee,2 Dhrubaditya Mitra,1 and Dibyendu Nandy3 1NORDITA, Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden 2School of Electrical Engg and Computer Science, KTH Royal Institute of Technology, Sweden 3Center of Excellence in Space Sciences India and Department of Physical Sciences, Indian Insitute of Science Education and Research Kolkata, Mohanpur 741246, India ABSTRACT The dynamic activity of the Sun, governed by its cycle of sunspots { strongly mag- netized regions that are observed on its surface { modulate our solar system space environment creating space weather. Severe space weather leads to disruptions in satellite operations, telecommunications, electric power grids and air-traffic on po- lar routes. Forecasting the cycle of sunspots, however, has remained a challenging problem. We use reservoir computing { a model-free, neural{network based machine- learning technique { to forecast the upcoming solar cycle, sunspot cycle 25. The standard algorithm forecasts that solar cycle 25 is going to last about ten years, the maxima is going to appear in the year 2024 and the maximum number of sunspots is going to be 113 (±15). We also develop a novel variation of the standard algorithm whose forecasts for duration and peak timing matches that of the standard algorithm, but whose peak amplitude forecast is 124 (±2) { within the upper bound of the stan- dard reservoir computing algorithm. We conclude that sunspot cycle 25 is likely to be a weak, lower than average solar cycle, somewhat similar in strength to sunspot cycle 24. -
Irina N. Kitiashvili (NASA Ames Research Center)
Global Evolution of Solar Magnetic Fields and Prediction of Solar Activity Cycles Irina N. Kitiashvili (NASA Ames Research Center) Prediction of solar activity cycles is challenging because the physical processes inside the Sun involve a broad range of multiscale dynamics that no model can reproduce, and the available observations are highly limited and cover mostly surface layers. Helioseismology makes it possible to probe solar dynamics in the convective zone, but variations in the differential rotation and meridional circulation are currently available for only two solar activity cycles. It has been demonstrated that sunspot observations, which cover over 400 years, can be used to calibrate the Parker-Kleeorin-Ruzmaikin model and that the Ensemble Kalman Filter (EnKF) method can be used to link the model magnetic fields to sunspot observations to make reliable predictions of a following cycle. However, for more accurate predictions, it is necessary to use actual observations of the solar magnetic fields, which are available for only four solar cycles. This raises the question of how limitations in observational data and model uncertainties affect predictive capabilities and implies the need for the development of new forecast methodologies and validation criteria. In this presentation, I will discuss the influence of the limited number of available observations on the accuracy of EnKF estimates of solar cycle parameters. Data Assimilation Methodology Comparison of hemispheric sunspot numbers, Test ‘Prediction’ of Solar Cycles 23 and -
Solar Cycle Variation and Application to the Space Radiation Environment
NASA/TP- 1999-209369 Solar Cycle Variation and Application to the Space Radiation Environment John W. Wilson, Myung-Hee Y. Kim, Judy L. Shinn, Hsiang Tai Langley Research Center, Hampton, Virginia Francis A. Cucinotta, Gautam D. Badhwar Johnson Space Center, Houston, Texas Francis F. Badavi Christopher Newport University, Newport News, Virginia William Atwell Boeing North American, Houston, Texas September 1999 The NASA STI Program Office... in Profile Since its founding, NASA has been dedicated CONFERENCE PUBLICATION. to the advancement of aeronautics and space Collected papers from scientific and science. The NASA Scientific and Technical technical conferences, symposia, Information (STI) Program Office plays a key seminars, or other meetings sponsored or part in helping NASA maintain this co-sponsored by NASA. important role. SPECIAL PUBLICATION. Scientific, The NASA STI Program Office is operated by technical, or historical information from Langley Research Center, the lead center for NASA programs, projects, and missions, NASA's scientific and technical information. often concerned with subjects having The NASA STI Program Office provides substantial public interest. access to the NASA STI Database, the largest collection of aeronautical and space science STI in the world. The Program Office TECHNICAL TRANSLATION. English- is also NASA's institutional mechanism for language translations of foreign scientific disseminating the results of its research and and technical material pertinent to NASA's mission. development activities. These results are published by NASA in the NASA STI Report Series, which includes the following report Specialized services that complement the types: STI Program Office's diverse offerings include creating custom thesauri, building customized TECHNICAL PUBLICATION. -
Arxiv:2108.01412V1 [Astro-Ph.SR] 3 Aug 2021
Solar Physics DOI: 10.1007/•••••-•••-•••-••••-• A Dynamo-Based Prediction of Solar Cycle 25 Wei Guo1,2 · Jie Jiang1,2 · Jing-Xiu Wang3,4 © Springer •••• Abstract Solar activity cycle varies in amplitude. The last Cycle 24 is the weakest in the past century. Sun's activity dominates Earth's space environment. The frequency and intensity of the Sun's activity are accordant with the solar cycle. Hence there are practical needs to know the amplitude of the upcoming Cycle 25. The dynamo-based solar cycle predictions not only provide predic- tions, but also offer an effective way to evaluate our understanding of the solar cycle. In this article we apply the method of the first successful dynamo-based prediction developed for Cycle 24 to the prediction of Cycle 25, so that we can verify whether the previous success is repeatable. The prediction shows that Cycle 25 would be about 10% stronger than Cycle 24 with an amplitude of 126 (international sunspot number version 2.0). The result suggests that Cycle 25 will not enter the Maunder-like grand solar minimum as suggested by some publications. Solar behavior in about four to five years will give a verdict whether the prediction method captures the key mechanism for solar cycle variability, which is assumed as the polar field around the cycle minimum in the model. Keywords: Magnetic fields, Models • Solar Cycle, Models • Solar Cycle, Ob- servations 1. Introduction Solar Cycle 24 has been the weakest cycle during the past century. Before its start, there were 265 and 262 spotless days in the years 2008 and 2009, respec- B J. -
JSTP 6 1 2020 24-28.Pdf
Solar-Terrestrial Physics. 2020. Vol. 6. Iss. 1. P. 24–28. DOI: 10.12737/stp-61202002. © 2020 P.Yu. Gololobov, P.A. Krivoshapkin, G.F. Krymsky, S.K. Gerasimova. Published by INFRA-M Academic Publishing House Original Russian version: P.Yu. Gololobov, P.A. Krivoshapkin, G.F. Krymsky, S.K. Gerasimova, published in Solnechno-zemnaya fizika. 2020. Vol. 6. Iss. 1. P. 30–35. DOI: 10.12737/szf-61202002. © 2020 INFRA-M Academic Publishing House (Nauchno-Izdatelskii Tsentr INFRA-M) INVESTIGATING THE INFLUENCE OF GEOMETRY OF THE HELIOSPHERIC NEUTRAL CURRENT SHEET AND SOLAR ACTIVITY ON MODULATION OF GA- LACTIC COSMIC RAYS WITH A METHOD OF MAIN COMPONENTS P.Yu. Gololobov G.F. Krymsky Yu.G. Shafer Institute of Cosmophysical Research Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS, and Aeronomy SB RAS, Yakutsk, Russia, [email protected] Yakutsk, Russia, [email protected] P.A. Krivoshapkin S.K. Gerasimova Yu.G. Shafer Institute of Cosmophysical Research Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS, and Aeronomy SB RAS, Yakutsk, Russia, [email protected] Yakutsk, Russia, [email protected] Abstract. The work studies the cumulative modulat- factors in the modulation. The modulation character is ing effect of the geometry of the interplanetary magnetic shown to strongly depend on the polarity of the Sun’s field’s neutral current sheet and solar activity on propa- general magnetic field. Results of the study confirm the gation of galactic cosmic rays in the heliosphere. The existing theoretical concepts of the heliospheric modula- role of each factor on the modulation of cosmic rays is tion of cosmic rays and reflect its peculiarities for al- estimated using a method of main components. -
Will Solar Cycles 25 and 26 Be Weaker Than Cycle
Solar Physics DOI: 10.1007/•••••-•••-•••-••••-• Will Solar Cycles 25 and 26 Be Weaker than Cycle 24 ? J. Javaraiah c Springer •••• Abstract The study of variations in solar activity is important for understand- ing the underlying mechanism of solar activity and for predicting the level of activity in view of the activity impact on space weather and global climate. Here we have used the amplitudes (the peak values of the 13-month smoothed international sunspot number) of Solar Cycles 1 – 24 to predict the relative am- plitudes of the solar cycles during the rising phase of the upcoming Gleissberg cycle. We fitted a cosine function to the amplitudes and times of the solar cycles after subtracting a linear fit of the amplitudes. The best cosine fit shows overall properties (periods, maxima, minima, etc.) of Gleissberg cycles, but with large uncertainties. We obtain a pattern of the rising phase of the upcoming Gleissberg cycle, but there is considerable ambiguity. Using the epochs of violations of the Gnevyshev-Ohl rule (G-O rule) and the ‘tentative inverse G-O rule’ of solar cycles during the period 1610 – 2015, and also using the epochs where the orbital angular momentum of the Sun is steeply decreased during the period 1600 – 2099, we infer that Solar Cycle 25 will be weaker than Cycle 24. Cycles 25 and 26 will have almost same strength, and their epochs are at the minimum between the current and upcoming Gleissberg cycles. In addition, Cycle 27 is expected to be stronger than Cycle 26 and weaker than Cycle 28, and Cycle 29 is expected to be stronger than both Cycles 28 and 30.