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 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 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 Long-term solar activity and terrestrial connections. Part II: at the beckon of the sun?

1998 ◽  
Vol 16 (5) ◽  
pp. 492-509 ◽  
Author(s):  
N. D. Diamantides
Keyword(s):  
Solar Activity ◽  
Time Course ◽  
Analytical Tool ◽  
The Sun ◽  
Nonlinear Part ◽  
The Past ◽  
Research Task ◽  
Present Context ◽  
Long Term Behavior

Abstract. The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun - either now or in the past - the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.Key words. Solar activity · Kolmogorov algorithm

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>

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.

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 Long-term solar activity and terrestrial connections. Part I: theory

1998 ◽  
Vol 16 (5) ◽  
pp. 479-491
Author(s):  
N. D. Diamantides
Keyword(s):  
Solar Activity ◽  
Time Course ◽  
Analytical Tool ◽  
The Sun ◽  
Nonlinear Part ◽  
The Past ◽  
Research Task ◽  
Present Context ◽  
Long Term Behavior

Abstract. The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun – either now or in the past, the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.Key words. Solar activity · Kolmogorov algorithm

A Study of Variation of the 11-yr Solar Cycle before the onset of the Spoerer Minimum based on Annually measured 14C Content in tree Rings

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1749-1754 ◽  
Author(s):  
Toru Moriya ◽  
Hiroko Miyahara ◽  
Motonari Ohyama ◽  
Masataka Hakozaki ◽  
Mirei Takeyama ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Cycle Length ◽  
Detailed Mechanism ◽  
Grand Minimum ◽  
The Past ◽  
Shimokita Peninsula ◽  
Solar Cycle Length ◽  
Long Term Variations

ABSTRACTProxy-based observations of solar activity in the past have revealed long-term variations, such as the Gleissberg cycle (~88 yr), de Vries cycle (~200 yr), and the Hallstatt cycle (~2000 yr). Such long-term variations of solar activity sometimes cause the disappearance of sunspots for several decades. Currently, solar activity is becoming weaker, and there is a possibility that another long-term sunspot minimum could occur. However, the detailed mechanism of the weakening in solar activity is unknown, and the prediction of solar activity is ambiguous. In this study, we investigate the transitions of solar cycle length before the onset of the Spoerer Minimum, the longest grand minimum in the past 2000 yr. We measured the 14C content in an asunaro tree (Thujopsis dolabrata) excavated at Shimokita Peninsula from 1368–1420 CE using the compact AMS system at Yamagata University. It is found that the solar cycle lengthened to be 14–16 yr from 2 cycles before the onset of the Spoerer Minimum.

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