Solar quiet daily (Sq) geomagnetic variation during minimum of solar cycle 23/24

2020 ◽  
Author(s):  
Anatoly Soloviev ◽  
Artem Smirnov
Keyword(s):  
Solar Activity ◽  
Current System ◽  
Geomagnetic Variation ◽  
Solar Cycles ◽  
Middle Latitudes ◽  
Observatory Data ◽  
Summer Hemisphere ◽  
Orthogonal Components ◽  
E Region ◽  
Good Agreement

<p class="Textbody"><span lang="EN-US">The most regular of all daily geomagnetic field variations is the so-called solar quiet, or Sq, variation. It is attributed to the two current vortices flowing in the E-region of the dayside ionosphere. We present an investigation of the time-dependent parameters of Sq variation for the historical minimum of solar activity in 2008. We apply "Measure of Anomalousness" algorithm to detection of magnetically quiet days. The global maps of seasonal Sq amplitudes of the three orthogonal components are derived using 75 INTERMAGNET and 46 SuperMAG stations at low and middle latitudes. The global Sq amplitudes are compared to the previous Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model simulations and show good agreement. Significant variability was found in Sq(X) and Sq(Y) based on the solar activity and latitude, while almost no difference is observed in Sq(Z) for across all latitudes and seasons. We analyze equivalent Sq current system using observatory data from the Australian mainland and narrow European-African latitudinal segment. Sq current system also strongly depends on solar activity, as current vortices are strongest in the local summer-hemisphere and disintegrate during local winter. The dynamics of Sq variation along the solar cycles 23 and 24 is also discussed and compared to Swarm-based spherical harmonic Sq model.</span></p>

scholarly journals Solar cycle 22 control on daily geomagnetic variation at Terra Nova Bay (Antarctica)

1998 ◽  
Vol 41 (5-6) ◽  
Author(s):  
L. Cafarella ◽  
A. Meloni ◽  
P. Palangio
Keyword(s):  
Solar Cycle ◽  
Time Variation ◽  
Daily Variation ◽  
Current System ◽  
Geomagnetic Variation ◽  
Field Variation ◽  
Terra Nova Bay ◽  
Polar Latitude ◽  
Observatory Data ◽  
Terra Nova

Nine summer geomagnetic observatory data (1986-1995) from Terra Nova Bay Base, Antarctica (Lat.74.690S, Long. 164.120E, 80.040S magnetic latitude) are used to investigate the behaviour of the daily variation of the geomagnetic field at polar latitude. The instrumentation includes a proton precession magnetometer for total intensity |F| digital recordings; DI magnetometers for absolute measuring of the angular elements D and I and a three axis flux-gate system for acquiring H,D Z time variation data. We find that the magnetic time variation amplitude follows the solar cycle evolution and that the ratio between minimum solar median and maximum solar median is between 2-3 for intensive elements (H and Z) and 1.7 for declination(D). The solar cycle effect on geomagnetic daily variation elements amplitude in Antarctica, in comparison with previous studies, is then probably larger than expected. As a consequence, the electric current system that causes the daily magnetic field variation reveals a quite large solar cycle effect at Terra Nova Bay.

Nonlinear Prediction of Solar Cycle 25

2018 ◽  
Vol 13 (S340) ◽  
pp. 321-322
Author(s):  
Volkan Sarp ◽  
Ali Kılçık
Keyword(s):  
Solar Activity ◽  
Sunspot Number ◽  
Prediction Method ◽  
Solar Cycles ◽  
Nonlinear Prediction ◽  
Cycle 24 ◽  
And Performance ◽  
Prediction Approach ◽  
Good Agreement

AbstractSolar activity is a chaotic process and there are various approximations to forecast its long term and short term variations. But there is no prediction method that predicts the solar activity exactly. In this study, a nonlinear prediction approach was applied to international sunspot numbers and performance of predictions was tested for the last 5 solar cycles. These predictions are in good agreement with observed values of the tested solar cycles. According to these results, end of cycle 24 is expected at February, 2020 with 7.7 smoothed monthly mean sunspot number and maximum of cyle 25 is expected at May, 2024 with 119.6 smoothed monthly mean sunspot number.

scholarly journals Equinoctial asymmetry in solar activity variations of <I>Nm</I>F2 and TEC

2012 ◽  
Vol 30 (3) ◽  
pp. 613-622 ◽  
Author(s):  
Y. Chen ◽  
L. Liu ◽  
W. Wan ◽  
Z. Ren
Keyword(s):  
Solar Activity ◽  
Electron Density ◽  
High Solar Activity ◽  
Solar Cycles ◽  
Low Latitude ◽  
Middle Latitudes ◽  
Low Latitudes ◽  
Increase Rate ◽  
Dip Equator ◽  
The Difference

Abstract. The ionosonde NmF2 data (covering several solar cycles) and the JPL TEC maps (from 1998 through 2009) were collected to investigate the equinoctial asymmetries in ionospheric electron density and its variation with solar activity. With solar activity increasing, the equinoctial asymmetry of noontime NmF2 increases at middle latitudes but decreases or changes little at low latitudes, while the equinoctial asymmetry of TEC increases at all latitudes. The latitudinal feature of the equinoctial asymmetry at high solar activity is different from that at low solar activity. The increases of NmF2 and TEC with the solar proxy P = (F10.7+F10.7A)/2 also show equinoctial asymmetries that depend on latitudes. The increase rate of NmF2 with P at March equinox (ME) is higher than that at September equinox (SE) at middle latitudes, but the latter is higher than the former at the EIA crest latitudes, and the difference between them is small at the EIA trough latitudes. The phenomenon of higher increase rate at SE than at ME does not appear in TEC. The increase rate of noontime TEC with P at ME is higher than that at SE at all latitudes, and the difference between them peaks at both sides of dip equator. It is mentionable that the equinoctial asymmetries of NmF2 and TEC increase rates present some longitudinal dependence at low latitude. The influences of equinoctial differences in the thermosphere and ionospheric dynamics processes on the equinoctial asymmetry of the electron density were briefly discussed.

Solar flare effect on the ionospheric current in the polar region: a new phenomena

2020 ◽  
Author(s):  
Masatoshi Yamauchi ◽  
Magnar Johnsen ◽  
Carl-Fredrik Enell
Keyword(s):  
Solar Flare ◽  
Electron Density ◽  
Current System ◽  
Radar Data ◽  
Oscillation Period ◽  
Lower Latitude ◽  
Solar Cycles ◽  
Geomagnetic Disturbances ◽  
Density Enhancement ◽  
E Region

&lt;p&gt;Solar flares are known to enhance the ionospheric electron density in the D- and E-region, enhancing twin vortex pattern in the dayside (e.g., Curto et al., 1994). &amp;#160;The geomagnetic deviation due to this current system is called as &quot;crochet&quot; or &quot;SFE (solar flare effect)&quot;. &amp;#160;For X-flares, the crochet is easily detected as an enhancement in ASY-D index (Sing et al., 2012). &amp;#160;Since the effect is expected stronger at low solar zenith angles where solar radiation is high, high-latitude behavior (&gt; 70&amp;#176; geographic latitudes: GGlat) has not been well studied and simply assumed as minor (such as weak return current).&lt;/p&gt;&lt;p&gt;However, the X flares on 6 September 2017 (X2.2 at 9 UT and X9.3 at 12 UT), caused large non-substorm geomagnetic disturbances at high latitudes, lasting much longer than the burst of electron density enhancement in the the D- and E-region (Yamauchi et al., 2018). &amp;#160;Both the polarity and duration turned out to be different from mid-latitude crochet which is characterized by short-lived (&lt; 30 min) dH&lt;0: dH is positive for over 5 hours with much higher amplitude than the crochet although the event took place near equator. &amp;#160;In addition, this dH showed oscillations on the order of 30 minute. &amp;#160;Since the X-ray intensity during 12-17 UT was higher than X-flare criterion until 17 UT, this long-lasting dH&gt;0 with peak at 74-75 GGLat must also be caused by the X-flare. &amp;#160;The EISCAT radar data showed strong enhancement of convection lasting hours after the flare onset and relevant bursty (&lt; 10 min) enhancement of the electron density. &amp;#160;This is consistent with long-lasting positive dH. &amp;#160;On the other hand, density oscillation period is about 15 min and different from the oscillation period of dH. &amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;Using Norwegian geomagnetic chain and EISCAT data, we examined X flares (&gt; X2.0) for past two solar cycles, and found that (1) dH&gt;0 at &gt; 70 GGLAT with dH&lt;0 (and positive ASY-D change is quite common) at lower latitude, (2) duration of crochet (dH&lt;0) is shorter at higher latitude as the start timing and amplitude of dH&gt;0 becomes earlier and larger at higher latitude, (3) at some latitude, crochet (dH&lt;0) disappears and dH&gt;0 dominates the entire period much longer than the crochet, and (4) electron density enhancement is spike-like no matter the duration of X-flare. &amp;#160;We interpret this long-lasting dH&gt;0 is caused by independent mechanism from crochet.&lt;/p&gt;&lt;p&gt;Reference&lt;br&gt;Curto et al. (1994): doi:10.1029/93JA02270&lt;br&gt;Singh et al. (2012): doi:10.1016/j.jastp.2011.12.010&lt;br&gt;Yamauchi et al. (2018): doi:10.1029/2018SW00193&lt;/p&gt;

scholarly journals Measurement of geomagnetically induced current (GIC) around Tokyo, Japan

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Shinichi Watari ◽  
Satoko Nakamura ◽  
Yusuke Ebihara
Keyword(s):  
Solar Flare ◽  
Geomagnetic Storms ◽  
Power Grids ◽  
Geomagnetic Variation ◽  
Induced Current ◽  
Interplanetary Shocks ◽  
Geomagnetic Disturbances ◽  
Geomagnetically Induced Current ◽  
Middle Latitudes ◽  
Sudden Commencements

AbstractWe need a typical method of directly measuring geomagnetically induced current (GIC) to compare data for estimating a potential risk of power grids caused by GIC. Here, we overview GIC measurement systems that have appeared in published papers, note necessary requirements, report on our equipment, and show several examples of our measurements in substations around Tokyo, Japan. Although they are located at middle latitudes, GICs associated with various geomagnetic disturbances are observed, such as storm sudden commencements (SSCs) or sudden impulses (SIs) caused by interplanetary shocks, geomagnetic storms including a storm caused by abrupt southward turning of strong interplanetary magnetic field (IMF) associated with a magnetic cloud, bay disturbances caused by high-latitude aurora activities, and geomagnetic variation caused by a solar flare called the solar flare effect (SFE). All these results suggest that GIC at middle latitudes is sensitive to the magnetospheric current (the magnetopause current, the ring current, and the field-aligned current) and also the ionospheric current.

scholarly journals On the Prediction of Solar Cycles

Solar Physics ◽  
2021 ◽  
Vol 296 (1) ◽  
Author(s):  
V. Courtillot ◽  
F. Lopes ◽  
J. L. Le Mouël
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Transfer Function ◽  
Singular Spectrum Analysis ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Planetary Motion ◽  
Data Sets ◽  
Solar Cycles ◽  
Jovian Planets

AbstractThis article deals with the prediction of the upcoming solar activity cycle, Solar Cycle 25. We propose that astronomical ephemeris, specifically taken from the catalogs of aphelia of the four Jovian planets, could be drivers of variations in solar activity, represented by the series of sunspot numbers (SSN) from 1749 to 2020. We use singular spectrum analysis (SSA) to associate components with similar periods in the ephemeris and SSN. We determine the transfer function between the two data sets. We improve the match in successive steps: first with Jupiter only, then with the four Jovian planets and finally including commensurable periods of pairs and pairs of pairs of the Jovian planets (following Mörth and Schlamminger in Planetary Motion, Sunspots and Climate, Solar-Terrestrial Influences on Weather and Climate, 193, 1979). The transfer function can be applied to the ephemeris to predict future cycles. We test this with success using the “hindcast prediction” of Solar Cycles 21 to 24, using only data preceding these cycles, and by analyzing separately two 130 and 140 year-long halves of the original series. We conclude with a prediction of Solar Cycle 25 that can be compared to a dozen predictions by other authors: the maximum would occur in 2026.2 (± 1 yr) and reach an amplitude of 97.6 (± 7.8), similar to that of Solar Cycle 24, therefore sketching a new “Modern minimum”, following the Dalton and Gleissberg minima.

Solar-type periodicities in the climate variability of Northern Fennoscandia during the last three centuries: Real influence of solar activity or natural instability in the climate system

The Holocene ◽  
2021 ◽  
pp. 095968362110604
Author(s):  
Maxim Ogurtsov ◽  
Samuli Helama ◽  
Risto Jalkanen ◽  
Högne Jungner ◽  
Markus Lindholm ◽  
...  
Keyword(s):  
Solar Activity ◽  
Climate Variability ◽  
Western Siberia ◽  
Climate System ◽  
Solar Cycles ◽  
Activity Data ◽  
The Past ◽  
Proxy Records ◽  
Northern Fennoscandia ◽  
Solar Type

Fifteen proxy records of summer temperature in Fennoscandia, Northern Europe and in Yamal and Taymir Peninsulas (Western Siberia) were analyzed for the AD 1700–2000 period. Century-long (70–100 year) and quasi bi-decadal periodicities were found from proxy records representing different parts of Fennoscandia. Decadal variation was revealed in a smaller number of records. Statistically significant correlations were revealed between the timescale-dependent components of temperature variability and solar cycles of Schwabe (~11 year), Hale (~22 year), and Gleissberg (сentury-long) as recorded in solar activity data. Combining the results from our correlation analysis with the evidence of solar-climatic linkages over the Northern Fennoscandia obtained over the past 20 years suggest that there are two possible explanations for the obtained solar-proxy relations: (a) the Sun’s activity actually influences the climate variability in Northern Fennoscandia and in some regions of the Northern Hemisphere albeit the mechanism of such solar-climatic linkages are yet to be detailed; (b) the revealed solar-type periodicities result from natural instability of climate system and, in such a case, the correlations may appear purely by chance. Multiple lines of evidence support the first assumption but we note that the second one cannot be yet rejected. Guidelines for further research to elucidate this question are proposed including the Fisher’s combined probability test in the presence of solar signal in multiple proxy records.

scholarly journals The equatorial E-region and its plasma instabilities: a tutorial

2009 ◽  
Vol 27 (4) ◽  
pp. 1509-1520 ◽  
Author(s):  
D. T. Farley
Keyword(s):  
Current System ◽  
Three Dimensional ◽  
Plasma Instabilities ◽  
Basic Physics ◽  
Electrojet Current ◽  
Fluid Theory ◽  
E Region ◽  
Kinetic Effects ◽  
The One ◽  
Observational Techniques

Abstract. In this short tutorial we first briefly review the basic physics of the E-region of the equatorial ionosphere, with emphasis on the strong electrojet current system that drives plasma instabilities and generates strong plasma waves that are easily detected by radars and rocket probes. We then discuss the instabilities themselves, both the theory and some examples of the observational data. These instabilities have now been studied for about half a century (!), beginning with the IGY, particularly at the Jicamarca Radio Observatory in Peru. The linear fluid theory of the important processes is now well understood, but there are still questions about some kinetic effects, not to mention the considerable amount of work to be done before we have a full quantitative understanding of the limiting nonlinear processes that determine the details of what we actually observe. As our observational techniques, especially the radar techniques, improve, we find some answers, but also more and more questions. One difficulty with studying natural phenomena, such as these instabilities, is that we cannot perform active cause-and-effect experiments; we are limited to the inputs and responses that nature provides. The one hope here is the steadily growing capability of numerical plasma simulations. If we can accurately simulate the relevant plasma physics, we can control the inputs and measure the responses in great detail. Unfortunately, the problem is inherently three-dimensional, and we still need somewhat more computer power than is currently available, although we have come a long way.

scholarly journals Construction of a century solar chromosphere data set for solar activity related research

2017 ◽  
Vol 3 (2) ◽  
pp. 5-8
Author(s):  
Линь Ганхуа ◽  
Lin Ganghua ◽  
Ван Сяо-Фань ◽  
Wang Xiao Fan ◽  
Ян Сяо ◽  
...  
Keyword(s):  
Data Mining ◽  
Solar Activity ◽  
Space Weather ◽  
Large Scale ◽  
Abnormal Behavior ◽  
Solar Chromosphere ◽  
Solar Cycles ◽  
Data Set ◽  
Related Research ◽  
Data Mining Algorithms

This article introduces our ongoing project “Construction of a Century Solar Chromosphere Data Set for Solar Activity Related Research”. Solar activities are the major sources of space weather that affects human lives. Some of the serious space weather consequences, for instance, include interruption of space communication and navigation, compromising the safety of astronauts and satellites, and damaging power grids. Therefore, the solar activity research has both scientific and social impacts. The major database is built up from digitized and standardized film data obtained by several observatories around the world and covers a timespan more than 100 years. After careful calibration, we will develop feature extraction and data mining tools and provide them together with the comprehensive database for the astronomical community. Our final goal is to address several physical issues: filament behavior in solar cycles, abnormal behavior of solar cycle 24, large-scale solar eruptions, and sympathetic remote brightenings. Significant progresses are expected in data mining algorithms and software development, which will benefit the scientific analysis and eventually advance our understanding of solar cycles.

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