scholarly journals Optical instrumentation for chromospheric monitoring during solar cycle 25 at Paris and Côte d’Azur observatories

2020 ◽  
Vol 10 ◽  
pp. 31
Author(s):  
Jean-Marie Malherbe ◽  
Thierry Corbard ◽  
Kevin Dalmasse
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Calibration Method ◽  
Line Profiles ◽  
Short Term ◽  
Optical Instruments ◽  
Dynamic Events

We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications. Two optical instruments are fully dedicated to this task and we summarize their capabilities. Short-term and fast-cadence observations of the chromosphere will be performed automatically at Calern observatory (Côte d’Azur), where dynamic events, as flare development, Moreton waves, filament instabilities and Coronal Mass Ejections onset, will be tracked. This new set of telescopes will operate in 2021 with narrow bandpass filters selecting Hα and CaII K lines. We present the instrumental design and a simulation of future images. At Meudon, the Spectroheliograph is well adapted to the long-term and low-cadence survey of chromospheric activity by recently improved and optimized spectroscopic means. Surface scans deliver daily (x, y, λ) datacubes of Hα, CaII K and CaII H line profiles. We describe the nature of available data and emphasize the new calibration method of spectra.

scholarly journals Geomagnetic activity recurrences for predicting the amplitude and shape of solar cycle N. 25

2021 ◽  
Author(s):  
Piero Diego ◽  
Monica Laurenza
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Space Weather ◽  
Climate Data ◽  
Activity Prediction ◽  
Successful Prediction ◽  
Physical Phenomena ◽  
Maximum Sunspot

The prediction of solar activity is one of the most challenging topics among the various Space    Weather and Space Climate issues. In the last decades, the constant enhancement of Space Climate    data allowed to improve the comprehension of the related physical phenomena and the statistical    bases for prediction algorithms. For this purpose, we used geomagnetic indices to provide a pow erful algorithm (see Diego et al 2010) for the solar activity prediction, based on the evaluation of    the recurrence rate in the geomagnetic activity. The aim of this paper is to present the validation    of our algorithm over solar cycle n. 24, for which a successful prediction was made, and upgrade    it to forecast the shape and time as well as the amplitude of the upcoming cycle n. 25. Contrary    to the consensus, we predict it to be quite high, with a maximum sunspot number of 205  ±  29,  that should be reached in the first half of 2023. This prediction is consistent with the scenario in    which the long-term Gleissberg cycle has reached its minimum in cycle n. 24 and the rising phase  is beginning.

scholarly journals SOLAR SPECTROPOLARIMETER FOR SPACE WEATHER FORECAST

2019 ◽  
Vol 5 (4) ◽  
pp. 21-26
Author(s):  
Evgeniy Ivanov ◽  
Aleksey Gubin ◽  
Sergey Lesovoi ◽  
Ramses Zaldivar Estrada
Keyword(s):  
Solar Activity ◽  
Space Weather ◽  
Linear Polarization ◽  
Coronal Mass Ejections ◽  
Software Defined Radio ◽  
Low Cost ◽  
Weather Forecast ◽  
The Internet ◽  
Type Ii ◽  
Continuous Observation

We propose a project of the meter wavelength range solar spectropolarimeter designed for a ground-based network developing for space weather forecast. The Software-Defined Radio (SDR) solution is chosen to meet such instrument network requirements as specification identity, low cost, possibility of controlling and transmitting data remotely via the Internet. Along with these requirements, the proposed SDR solution allows us to measure Stokes I and V easily, which contrasts the proposed instrument with e-CALLISTO network spectropolarimeters, most of which can record only one linear polarization. Deployment of such instruments at various longitudes will allow continuous observation of type II bursts, often related to coronal mass ejections (CMEs) — the most geoeffective solar activity events that affect the space weather significantly.

scholarly journals Stability of solar correction for calculating ionospheric trends

2016 ◽  
Vol 34 (12) ◽  
pp. 1191-1196 ◽  
Author(s):  
Jan Laštovička ◽  
Dalia Burešová ◽  
Daniel Kouba ◽  
Peter Križan
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Global Climate ◽  
Standard Technique ◽  
Model Data ◽  
Data Set ◽  
Long Term Trends ◽  
Cycle 24 ◽  
Activity Dependence

Abstract. Global climate change affects the whole atmosphere, including the thermosphere and ionosphere. Calculations of long-term trends in the ionosphere are critically dependent on solar activity (solar cycle) correction of ionospheric input data. The standard technique is to establish an experimental model via calculating the dependence of ionospheric parameter on solar activity from the whole analysed data set, subtract these model data from observed data and analyse the trend of residuals. However, if the solar activity dependence changes with time, the solar correction calculated from the whole data set may result in miscalculating the ionospheric trends. To test this, data from two European ionospheric stations – Juliusruh and Slough/Chilton – which provide long-term reliable data, have been used for the period 1975–2014. The main result of this study is the finding that the solar activity correction used in calculating ionospheric long-term trends need not be stable, as was assumed in all previous investigations of ionospheric trends. During the previous solar cycle 23 and the current solar cycle 24, the solar activity correction appears to be different from that for the previous period and the Sun seems to behave in a different way than throughout the whole previous era of ionospheric measurements. In future ionospheric trend investigations the non-stability of solar activity correction has to be very seriously taken into account, because it can substantially affect calculated long-term trends of ionospheric parameters.

Cosmic-ray long-term variations due to the solar activity for the 22nd solar cycle

1995 ◽  
Vol 16 (9) ◽  
pp. 245-248 ◽  
Author(s):  
L. Marmatsouri ◽  
A. Vassilaki ◽  
H. Mavromichalaki ◽  
B. Petropoulos
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Ray ◽  
Long Term Variations

scholarly journals SOLAR SPECTROPOLARIMETER FOR SPACE WEATHER FORECAST

2019 ◽  
Vol 5 (4) ◽  
pp. 26-33
Author(s):  
Evgeniy Ivanov ◽  
Aleksey Gubin ◽  
Sergey Lesovoi ◽  
Ramses Zaldivar Estrada
Keyword(s):  
Solar Activity ◽  
Space Weather ◽  
Linear Polarization ◽  
Coronal Mass Ejections ◽  
Software Defined Radio ◽  
Low Cost ◽  
Weather Forecast ◽  
The Internet ◽  
Type Ii ◽  
Continuous Observation

We propose a project of the meter wavelength range solar spectropolarimeter designed for a ground-based network developing for space weather forecast. The Software-Defined Radio (SDR) solution is chosen to meet such instrument network requirements as specification identity, low cost, possibility of controlling and transmitting data remotely via the Internet. Along with these requirements, the proposed SDR solution allows us to measure Stokes I and V easily, which contrasts the proposed instrument with e-CALLISTO network spectropolarimeters, most of which can record only one linear polarization. Deployment of such instruments at various longitudes will allow continuous observation of type II bursts, often related to coronal mass ejections (CMEs) — the most geoeffective solar activity events that affect the space weather significantly.

scholarly journals Temporal peculiarities in environment factors change and in physiological dynamics of the indoor plants during low solar activity.

2020 ◽  
Author(s):  
P.A. Kashulin ◽  
◽  
N.V. Kalacheva ◽  
E.Y. Zhurina ◽  
◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Time Course ◽  
Meteorological Factors ◽  
Physiological Characteristics ◽  
Environment Factors ◽  
Indoor Plants ◽  
Natural Factors

The long-term time-course of some environmental meteorological factors and physiological characteristics of indoor Marantha leoconeuraand Ctenanthe setosaplants cultivated under controlled lab conditions were investigated during the months of low solar activity of current solar cycle. The two weeks cycles, circaseptan and circasemiceptan cycles in natural factors change as well as in plant multi-diurnal physiological dynamics were revealed. The results points out on the cosmic provenance of the found rhythms.

scholarly journals On the inclusion of data from solar cycle 19 to estimate F2 layer characteristic long term trends

2015 ◽  
Vol 58 (4) ◽  
Author(s):  
Blas F. de Haro Barbas ◽  
Ana G. Elias
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Solar Radio ◽  
Data Series ◽  
Radio Flux ◽  
Solar Radio Flux ◽  
Long Term Trends ◽  
Layer Characteristic ◽  
Dominant Influence

<p>The effect of including solar cycle 19 (1954-1964) in ionospheric trend estimation is assessed using experimental foF2 values. The dominant influence on the F2 layer is solar EUV radiation. In fact, around 90% of inter-annual variance of ionospheric parameters, such as foF2, is explained by solar EUV proxies such as the sunspot number, Rz, and solar radio flux at 10.7 cm, F10.7. This makes necessary to filter out solar activity effects prior to long term trends estimation, which is reduced at most to the remaining 10% variance. In general solar activity is filtered assessing the residuals of a linear regression between foF2 and Rz, or between foF2 and F10.7. Solar cycle 19 is a strong cycle during which Rz and F10.7 exceeded the values beyond which the ionosphere does not respond linearly to a further increase in EUV radiation. This effect, called saturation, implies a break down of the linearity between foF2 and EUV, and results in persistent negative residuals during this period. Since solar cycle 19 is at the beginning of the time series, trends result to be positive, or less negative, than trends without considering this period. In this case the filtering process is generating a “spurious” trend in the filtered data series which may lead to erroneous conclusions. hmF2 that do not present a saturation effect is also analyzed.</p><div> </div>

scholarly journals COMMISSION 10: SOLAR ACTIVITY

2008 ◽  
Vol 4 (T27A) ◽  
pp. 79-103
Author(s):  
James A. Klimchuk ◽  
Lidia van Driel-Gesztelyi ◽  
Carolus J. Schrijver ◽  
Donald B. Melrose ◽  
Lyndsay Fletcher ◽  
...  
Keyword(s):  
Solar Activity ◽  
Coronal Mass Ejection ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Solar Physics ◽  
Scientific Progress ◽  
Magnetic Clouds ◽  
Exciting Time ◽  
Mass Ejection ◽  
Coronal Dimming

Commission 10 deals with solar activity in all of its forms, ranging from the smallest nanoflares to the largest coronal mass ejections. This report reviews scientific progress over the roughly two-year period ending in the middle of 2008. This has been an exciting time in solar physics, highlighted by the launches of the Hinode and STEREO missions late in 2006. The report is reasonably comprehensive, though it is far from exhaustive. Limited space prevents the inclusion of many significant results. The report is divided into the following sections: Photosphere and chromosphere; Transition region; Corona and coronal heating; Coronal jets; flares; Coronal mass ejection initiation; Global coronal waves and shocks; Coronal dimming; The link between low coronal CME signatures and magnetic clouds; Coronal mass ejections in the heliosphere; and Coronal mass ejections and space weather. Primary authorship is indicated at the beginning of each section.

Study of Long-Term Variations in Hemispheric Asymmetry of Solar Activity

2018 ◽  
Vol 13 (S340) ◽  
pp. 259-260
Author(s):  
B. Ravindra ◽  
J. Javaraiah
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Hemispheric Asymmetry ◽  
Sunspot Area ◽  
Sunspot Activity ◽  
Phase Lag ◽  
Double Peak ◽  
Northern And Southern Hemispheres ◽  
Long Term Variations

AbstractSunspot activity exhibits hemispheric asymmetry. We study the long-term variations in the hemispheric sunspot area from Kodaikanal white-light data during 1921 – 2011. The results on the presence or absence of double peak in an individual solar cycle, dominant hemispheric activity, and phase lag between the activities of northern and southern hemispheres, etc., are presented.

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