A neural network-based mid-term prognosis of geomagnetic storms that uses pre-storm effects related to current sheets and magnetic islands

2021 ◽  
Author(s):  
Mikhail Fridman
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Magnetic Islands ◽  
Solar Wind Density ◽  
Short Term ◽  
Storm Effects ◽  
Term Forecast ◽  
Advance Time

<p>Mid-term prognoses of geomagnetic storms require an improvement since theу are known to have rather low accuracy which does not exceed 40% in solar minimum. We claim that the problem lies in the approach. Current mid-term forecasts are typically built using the same paradigm as short-term ones and suggest an analysis of the solar wind conditions typical for geomagnetic storms. According to this approach, there is a 20-60 minute delay between the arrival of a geoeffective flow/stream to L1 and the arrival of the signal from the spacecraft to Earth, which gives a necessary advance time for a short-term prognosis. For the mid-term forecast with an advance time from 3 hours to 3 days, this is not enough. Therefore, we have suggested finding precursors of geomagnetic storms observed in the solar wind. Such precursors are variations in the solar wind density and the interplanetary magnetic field in the ULF range associated with crossings of magnetic cavities in front of the arriving geoeffective high-speed streams and flows (Khabarova et al., 2015, 2016, 2018; Adhikari et al., 2019). Despite some preliminary studies have shown that this might be a perspective way to create a mid-term prognosis (Khabarova 2007; Khabarova & Yermolaev, 2007), the problem of automatization of the prognosis remained unsolved.</p>

Neural network applications in geomagnetic storm prognosis based on the pre-storm occurrence of magnetic islands in the solar wind

2020 ◽  
Author(s):  
Mikhail Fridman
Keyword(s):  
Neural Network ◽  
Solar Wind ◽  
Particle Acceleration ◽  
Geomagnetic Storm ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Pattern Search ◽  
Small Scale ◽  
Magnetic Islands ◽  
Solar Wind Density

<p>So far, the problem of a short-term forecast of geomagnetic storms can be considered as solved. Meanwhile, mid-term prognoses of geomagnetic storms with an advance time from 3 hours to 3 days are still unsuccessful (see  https://www.swpc.noaa.gov/sites/default/files/images/u30/Max%20Kp%20and%20GPRA.pdf).</p><p> This fact suggests a necessity of looking for specific processes in the solar wind preceding geomagnetic storms. Knowing that magnetic cavities filled with magnetic islands and current sheets are formed in front of high-speed streams of any type (Khabarova et al., 2015, 2016, 2018; Adhikari et al., 2019), we have performed an analysis of the corresponding ULF variations in the solar wind density observed at the Earth's orbit from hours to days before the arrival of a geoeffective stream or flow. The fact of the occurrence of ULF-precursors of geomagnetic storms was noticed a long time ago (Khabarova 2007; Khabarova & Yermolaev, 2007) and related prognostic methods were recently developed (Kogai et al. 2019), while the problem of automatization of the prognosis remained unsolved.</p><p> A new geomagnetic storm forecast method, which employs a Recurrent Neural Network (RNN) for an automatic pattern search, is proposed. An ability of self-teaching and extracting deeply hidden non-linear patterns is the main advantage of Deep Neural Networks (DNNs) with multiple layers over traditional Machine Learning methods. We show a success of the RNN method, using either the unprocessed solar wind density data or Wavelet analysis coefficients as the input parameter for a DNN to perform an automatic mid-term prognosis of geomagnetic storms.  </p><p>Adhikari, L., et al. 2019, The Role of Magnetic Reconnection–associated Processes in Local Particle Acceleration in the Solar Wind, ApJ, 873, 1, 72, https://doi.org/10.3847/1538-4357/ab05c6<br>Kogai T.G. et al., Pre-storm ULF variations in the solar wind density and interplanetary magnetic field as key parameters to build a mid-term prognosis of geomagnetic storms. “GRINGAUZ 100: PLASMA IN THE SOLAR SYSTEM”, IKI RAS, Moscow, June 13–15, 2018, 140-143, ISBN 978-5-00015-043-6. https://www.researchgate.net/publication/327781146_Pre-storm_ULF_variations_in_the_solar_wind_density_and_interplanetary_magnetic_field_as_key_parameters_to_build_a_mid-term_prognosis_of_geomagnetic_storms<br> Khabarova O. V., et al. 2018,  Re-acceleration of energetic particles in large-scale heliospheric magnetic cavities, Proceedings of the IAU, 76-82, https://doi.org/10.1017/S1743921318000285 <br>Khabarova O.V., et al. Small-scale magnetic islands in the solar wind and their role in particle acceleration. II. Particle energization inside magnetically confined cavities. 2016, ApJ, 827, 122, http://iopscience.iop.org/article/10.3847/0004-637X/827/2/122<br>Khabarova O., et al. Small-scale magnetic islands in the solar wind and their role in particle acceleration. 1. Dynamics of magnetic islands near the heliospheric current sheet. 2015, ApJ, 808, 181, https://doi.org/10.1088/0004-637X/808/2/181</p><p>Khabarova O.V., Current Problems of Magnetic Storm Prediction and Possible Ways of Their Solving. Sun&Geosphere,  http://sg.shao.az/v2n1/SG_v2_No1_2007-pp-33-38.pdf , 2(1), 33-38, 2007</p><p>Khabarova O.V. & Yu.I.Yermolaev, Solar wind parameters' behavior before and after magnetic storms, JASTP, 70, 2-4, 2008, 384-390, http://dx.doi.org/10.1016/j.jastp.2007.08.024</p>

White-light solar corona structure observed by naked eye and processed images

2020 ◽  
Vol 495 (2) ◽  
pp. 2170-2178 ◽  
Author(s):  
Vojtech Rušin ◽  
Paul Prikryl ◽  
Emil A Prikryl
Keyword(s):  
Solar Wind ◽  
White Light ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Interplanetary Space ◽  
Coronal Holes ◽  
Human Vision ◽  
Naked Eye ◽  
Wide Range ◽  
White Light Corona

ABSTRACT Light and dark adaptation and luminance contrast enhancement are well-known characteristics of human vision that allow us to observe a wide range of light intensity not fully captured in standard camera images. The naked-eye observations of total eclipses, some recorded with spectacular detail in artists’ paintings, reveal structure that is consistent with images obtained by telescopes equipped with recording media. The actual shape of the corona during a total eclipse depends not only on the phase of the solar cycle but, as can be simply demonstrated, also on the day-to-day variability and spatial distribution of coronal intensity that is determined by solar surface magnetic fields, including the locations of coronal holes that are the sources of high-speed solar wind causing geomagnetic storms. The latter were very similar for the eclipses in 1932, 1994, and 2017, which is the main reason why the naked-eye observations, as well as the processed images (1994 and 2017), of the white-light corona displayed very similar shapes. White-light corona image processing is a useful technique to enhance the contrast to observe fine-scale structure that is consistent with the physics of the solar atmosphere shaped by the magnetic field drawn out into the interplanetary space by solar wind.

Recurrent high-speed solar wind co-rotating interaction region imprint on the ionosphere and atmosphere: GPS TEC variations and atmospheric gravity waves

2020 ◽  
Author(s):  
James M. Weygand ◽  
Paul Prikryl ◽  
Reza Ghoddousi-Fard ◽  
Lidia Nikitina ◽  
Bharat S. R. Kunduri
Keyword(s):  
Solar Wind ◽  
Gravity Waves ◽  
High Latitude ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Coronal Holes ◽  
Lower Thermosphere ◽  
Ionospheric Currents ◽  
Atmospheric Gravity Waves ◽  
Atmospheric Gravity

<p>High-speed streams (HSS) from coronal holes dominate solar wind structure in the absence of coronal mass ejections during solar minimum and the descending branch of solar cycle. Prominent and long-lasting coronal holes produce intense co-rotating interaction regions (CIR) on the leading edge of high-speed plasma streams that cause recurrent ionospheric disturbances and geomagnetic storms. Through solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system they affect the ionosphere and neutral atmosphere at high latitudes, and, at mid to low latitudes, by the transmission of the electric fields [1] and propagation of atmospheric gravity waves from the high-latitude lower thermosphere [2].</p><p>The high-latitude ionospheric structure, caused by precipitation of energetic particles, strong ionospheric currents and convection, results in changes of the GPS total electron content (TEC) and rapid variations of GPS signal amplitude and phase, called scintillation [3]. The GPS phase scintillation is observed in the ionospheric cusp, polar cap and auroral zone, and is particularly intense during geomagnetic storms, substorms and auroral breakups. Phase scintillation index is computed for a sampling rate of 50 Hz by specialized GPS scintillation receivers from the Canadian High Arctic Ionospheric Network (CHAIN). A proxy index of phase variation is obtained from dual frequency measurements of geodetic-quality GPS receivers sampling at 1 Hz, which include globally distributed receivers of the RT-IGS network that are monitored by the Canadian Geodetic Survey in near-real-time [4]. Temporal and spatial changes of TEC and phase variations following the arrivals of HSS/CIRs [5] are investigated in the context of ionospheric convection and equivalent ionospheric currents derived from  a ground magnetometer network using the spherical elementary current system method [6,7].</p><p>The Joule heating and Lorentz forcing in the high-latitude lower thermosphere have long been recognized as sources of internal atmospheric gravity waves (AGWs) [2] that propagate both upward and downward, thus providing vertical coupling between atmospheric layers. In the ionosphere, they are observed as traveling ionospheric disturbances (TIDs) using various techniques, e.g., de-trended GPS TEC maps [8].</p><p>In this paper we examine the influence on the Earth’s ionosphere and atmosphere of a long-lasting HSS/CIRs from recurrent coronal holes at the end of solar cycles 23 and 24. The solar wind MIA coupling, as represented by the coupling function [9], was strongly increased during the arrivals of these HSS/CIRs.</p><p> </p><p>[1] Kikuchi, T. and K. K. Hashimoto, Geosci. Lett. , 3:4, 2016.</p><p>[2] Hocke, K. and K. Schlegel, Ann. Geophys., 14, 917–940, 1996.</p><p>[3] Prikryl, P., et al., J. Geophys. Res. Space Physics, 121, 10448–10465, 2016.</p><p>[4] Ghoddousi-Fard et al., Advances in Space Research, 52(8), 1397-1405, 2013.</p><p>[5] Prikryl et al. Earth, Planets and Space, 66:62, 2014.</p><p>[6] Amm O., and A. Viljanen, Earth Planets Space, 51, 431–440, 1999.</p><p>[7] Weygand J.M., et al., J. Geophys. Res., 116, A03305, 2011.</p><p>[8] Tsugawa T., et al., Geophys. Res. Lett., 34, L22101, 2007.</p><p>[9] Newell P. T., et al., J. Geophys. Res., 112, A01206, 2007.</p>

scholarly journals High-speed solar wind stream effects on the topside ionosphere over Arecibo: A case study during solar minimum

2017 ◽  
Vol 44 (15) ◽  
pp. 7607-7617 ◽  
Author(s):  
Rajkumar Hajra ◽  
Bruce T. Tsurutani ◽  
Christiano G. M. Brum ◽  
Ezequiel Echer
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
High Speed ◽  
Topside Ionosphere ◽  
Solar Wind Stream ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals A Short-term Forecast of the Water Inflow to the Bureya Reservoir on the Basis of ECOMAG Model with the Use of Meteorological Forecasts

2017 ◽  
Author(s):  
Keyword(s):  
Hydrological Model ◽  
Meteorological Data ◽  
Water Inflow ◽  
Short Term ◽  
Short Term Forecast ◽  
Term Forecast ◽  
Diagnostic Potential ◽  
Meteorological Observations ◽  
Advance Time

A method of short-term forecast of water inflow to Bureya reservoir on the basis of a hydrological model and meteorological forecasts has been developed in order to improve the short-term planning effectiveness. A spatial-distribute physical/mathematical model of the runoff formation was used as a hydrological model. It was calibrated and validated by data of the retrospective hydro/meteorological observations in the Bureya River basin. Statistical criteria have shown good quality of modeling and high diagnostic potential of the model. Forecast calculations on the hydrological model with the seven days advance time can be done according the forecast meteorological data received on the basis of two atmosphere circulation models. A procedure of the forecast calculations’ correction with taking into account newly received hydrological information on water inflow to the reservoir has been applied to raise the hydrological forecasts reliability. Results of our operative test of the developed method of the water inflow to Bureya reservoir short-term forecast in 2016 are given.

scholarly journals Solar cycle effect on geomagnetic storms caused by interplanetary magnetic clouds

2006 ◽  
Vol 24 (12) ◽  
pp. 3383-3389 ◽  
Author(s):  
C.-C. Wu ◽  
R. P. Lepping
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storm ◽  
Solar Minimum ◽  
Geomagnetic Storms ◽  
Solar Maximum ◽  
Solar Wind Speed ◽  
Magnetic Clouds ◽  
Active Period ◽  
Quiet Period ◽  
Solar Wind Parameters

Abstract. We investigated geomagnetic activity which was induced by interplanetary magnetic clouds during the past four solar cycles, 1965–1998. We have found that the intensity of such geomagnetic storms is more severe in solar maximum than in solar minimum. In addition, we affirm that the average solar wind speed of magnetic clouds is faster in solar maximum than in solar minimum. In this study, we find that solar activity level plays a major role on the intensity of geomagnetic storms. In particular, some new statistical results are found and listed as follows. (1) The intensity of a geomagnetic storm in a solar active period is stronger than in a solar quiet period. (2) The magnitude of negative Bzmin is larger in a solar active period than in a quiet period. (3) Solar wind speed in an active period is faster than in a quiet period. (4) VBsmax in an active period is much larger than in a quiet period. (5) Solar wind parameters, Bzmin, Vmax and VBsmax are correlated well with geomagnetic storm intensity, Dstmin during a solar active period. (6) Solar wind parameters, Bzmin, and VBsmax are not correlated well (very poorly for Vmax) with geomagnetic storm intensity during a solar quiet period. (7) The speed of the solar wind plays a key role in the correlation of solar wind parameters vs. the intensity of a geomagnetic storm. (8) More severe storms with Dstmin≤−100 nT caused by MCs occurred in the solar active period than in the solar quiet period.

scholarly journals A case study of dayside reconnection under extremely low solar wind density conditions

2008 ◽  
Vol 26 (11) ◽  
pp. 3571-3583
Author(s):  
R. Maggiolo ◽  
J. A. Sauvaud ◽  
I. Dandouras ◽  
E. Luceck ◽  
H. Rème
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
High Speed ◽  
Radial Distance ◽  
Plasma Jets ◽  
Solar Wind Density ◽  
Ion Distribution ◽  
Dayside Magnetopause ◽  
Field Lines

Abstract. From 15 February 2004, 20:00 UT to 18 February 2004, 01:00 UT, the solar wind density dropped to extremely low values (about 0.35 cm−3). On 17 February, between 17:45 UT and 18:10 UT, the CLUSTER spacecraft cross the dayside magnetopause several times at a large radial distance of about 16 RE. During each of these crossings, the spacecraft detect high speed plasma jets in the dayside magnetopause and boundary layer. These observations are made during a period of southward and dawnward Interplanetary Magnetic Field (IMF). The magnetic shear across the local magnetopause is ~90° and the magnetosheath beta is very low (~0.15). We evidence the presence of a magnetic field of a few nT along the magnetopause normal. We also show that the plasma jets, accelerated up to 600 km/s, satisfy the tangential stress balance. These findings strongly suggest that the accelerated jets are due to magnetic reconnection between interplanetary and terrestrial magnetic field lines northward of the satellites. This is confirmed by the analysis of the ion distribution function that exhibits the presence of D shaped distributions and of a reflected ion population as predicted by theory. A quantitative analysis of the reflected ion population reveals that the reconnection process lasts about 30 min in a reconnection site located at a very large distance of several tens RE from the Cluster spacecraft. We also estimate the magnetopause motion and thickness during this event. This paper gives the first experimental study of magnetic reconnection during such rare periods of very low solar wind density. The results are discussed in the frame of magnetospheric response to extremely low solar wind density conditions.

scholarly journals Auroral electrojets variations caused by recurrent high-speed solar wind streams during the extreme solar minimum of 2008

2012 ◽  
Vol 117 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jianpeng Guo ◽  
Xueshang Feng ◽  
T. I. Pulkkinen ◽  
E. I. Tanskanen ◽  
Wenyao Xu ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
High Speed ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals Fe/O ratio behavior as an indicator of solar plasma state at different solar activity manifestations and in periods of their absence

2018 ◽  
pp. 33-58
Author(s):  
Геннадий Минасянц ◽  
Gennady Minasyants ◽  
Тамара Минасянц ◽  
Tamara Minasyants ◽  
Владимир Томозов ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Cosmic Rays ◽  
Ionization Potential ◽  
Solar Minimum ◽  
Geomagnetic Storms ◽  
Galactic Cosmic Rays ◽  
Ion Fluxes ◽  
Ion Energy ◽  
First Ionization Potential

We report the results of the investigation into plasma physical characteristics at various solar activity manifestations and in periods of their absence. These results have been obtained from quantitative estimates of the relative abundance of Fe/O ions in different energy ranges. Maximum values of the Fe/O ratio is shown to correspond to particle fluxes from impulsive flares for ions with energies <2 MeV/n (the most significant manifestation of the FIP effect). In particle fluxes from gradual flares, the Fe/O value decreases smoothly with ion energy and is noticeably inferior to values of fluxes in impulsive events. We have established that the properties of flares of solar cosmic rays indicate their belonging to a separate subclass in the total population of gradual events. Relying on variations in the abundance of Fe/O ions, we propose an xplanation of the solar plasma behavior during the development of flares of both classes. Magnetic clouds (a separate type of coronal mass ejections (CME)), which have regions of turbulent compression and are sources of strong geomagnetic storms, exhibit a relative composition of Fe ions comparable to the abundance of Fe in ion fluxes from gradual flares. We have found out that the Fe/O value can be used to detect penetration of energetic flare plasma into the CME body at the initial phase of their joint development and to estimate its relative contribution. During solar minimum with complete absence of sunspots, the Fe/O ratio during periods of “quiet” solar wind show absolutely low values of Fe/O=0.004–0.010 in the energy range from 2–5 to 30 MeV/n. This is associated with the manifestation of the cosmic ray anomalous component, which causes an increase in the intensity of ion fluxes with a high first ionization potential, including oxygen (O), and elements with a low first ionization potential (Fe) demonstrate weakening of the fluxes. As for particles with higher energies (Ek>30 MeV/n), the Fe/O increase is due to the decisive influence of galactic cosmic rays on the composition of impurity elements in the solar wind under solar minimum conditions. The relative content of heavy elements in galactic cosmic rays 30–500 MeV/n is similar to values in fluxes from gradual flares during high solar activity. During solar minimum without sunspots, the behavior of Fe/O for different ion energy ranges in plasma flows from coronal holes (CH) and in the solar wind exhibits only minor deviations. At the same time, plasma flows associated with the disturbed frontal CH region can be sources of moderate geomagnetic storms.

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