Continuous components of solar activity oscillation spectrum and forecasting of solar activity

Author(s):  
Dmitry Sokoloff ◽  
Peter Frick ◽  
Rodion Stepanov ◽  
Frank Stefani

<p>Spectrum of solar activity oscillations contains apart from the well-known 11-year activity cycle a continuous component, which includes, in particular, quasy-biennual oscillations as well as long-term oscillations including so-called Gleisberg cycle.  We suggest to consider the mid-term solar variability in terms of statistical dynamic of fully turbulent systems, where solid arguments are required to accept an isolated dominant frequency in a continuous (smooth) spectrum. What about the timescales longer than the Schwabe cycle, we consider them as a presence of long-term memory in solar dynamo and discuss statistical test for veryication of this interpretation. Sequences for statistical long-term forecast of solar activity are discussed.</p>

Author(s):  
Valery L. Yanchukovsky ◽  
◽  
Anastasiya Yu. Belinskaya ◽  

The relationship of Earth's seismicity with solar activity is investigated using the results of continuous long–term observations of cosmic ray intensity, solar activity and the number of strong earthquakes. Modulation of the flux of cosmic rays is used as information on the level of solar activity, processes on the Sun and interplanetary medium. The distribution of the number of sunspots, the intensity of cosmic rays and the number of strong earthquakes in the solar cycle is presented.


1994 ◽  
Vol 143 ◽  
pp. 28-36 ◽  
Author(s):  
Claus Fröhlich

Measurements of the total solar irradiance during the last 14 years from satellites show variations over time scales from minutes to years and decades. The most important variance is in the range from days to several months and is related to the photospheric features of solar activity: decreasing the irradiance during the appearance of sunspots, and increasing it by faculae and the bright magnetic network. Long-term modulation by the 11-year activity cycle is observed conclusively with the irradiance being higher during solar maximum. The accuracy of the determined variability and its interpretation in terms of manifestations of activity related features on the photosphere is discussed. Besides the direct influence of the spots, faculae and magnetic network more profound changes in the thermal transport seem to influence the behaviour of the solar photospheric radiation on the solar cycle and longer time scales.


2019 ◽  
Vol 491 (4) ◽  
pp. 5572-5578 ◽  
Author(s):  
P Frick ◽  
D Sokoloff ◽  
R Stepanov ◽  
V Pipin ◽  
I Usoskin

ABSTRACT Numerous analyses suggest the existence of various quasi-periodicities in solar activity. The power spectrum of solar activity recorded in sunspot data is dominated by the ∼11-yr quasi-periodicity, known as the Schwabe cycle. In the mid-term range (1 month–11 yr) a pronounced variability known as a quasi-biennial oscillation is widely discussed. In the shorter time-scale a pronounced peak, corresponding to the synodic solar rotation period (∼27 d), is observed. Here we revisit the mid-term solar variability in terms of statistical dynamics of fully turbulent systems, where solid arguments are required to accept an isolated dominant frequency in a continuous (smooth) spectrum. For this, we first undertook an unbiased analysis of the standard solar data, sunspot numbers and the F10.7 solar radio flux index, by applying a wavelet tool, which allows one to perform a frequency–time analysis of the signal. Considering the spectral dynamics of solar activity cycle by cycle, we showed that no single periodicity can be separated, in a statistically significant manner, in the specified range of periods. We examine whether a model of the solar dynamo can reproduce the mid-term oscillation pattern observed in solar data. We found that a realistically observed spectrum can be explained if small spatial (but not temporal) scales are effectively smoothed. This result is important because solar activity is a global feature, although monitored via small-scale tracers like sunspots.


Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 439-447 ◽  
Author(s):  
M G Ogurtsov ◽  
G E Kocharov ◽  
M Lindholm ◽  
M Eronen ◽  
Yu A Nagovitsyn

We performed a statistical analysis of the data on summer temperature anomalies in northern Fennoscandia (8–1995 AD) and found that a 70–130-yr cycle is present in this series during most of the time period. A comparison of the reconstructed northern Fennoscandia temperature with different indicators of solar activity (Wolf numbers, the length of solar Schwabe cycle, extended bi-decadal radiocarbon series, and data on sunspots observed by naked eye) shows that the more probable cause of the periodicity is the modulation of regional northern Fennoscandia climate by the long-term solar cycle of Gleissberg. The effect of this century-scale solar modulation of the global Northern Hemisphere temperature is weaker.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607


2011 ◽  
Vol 70 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Muriel Fanget ◽  
Catherine Thevenot ◽  
Caroline Castel ◽  
Michel Fayol

In this study, we used a paradigm recently developed ( Thevenot, Fanget, & Fayol, 2007 ) to determine whether 10-year-old children solve simple addition problems by retrieval of the answer from long-term memory or by calculation procedures. Our paradigm is unique in that it does not rely on reaction times or verbal reports, which are known to potentially bias the results, especially in children. Rather, it takes advantage of the fact that calculation procedures degrade the memory traces of the operands, so that it is more difficult to recognize them when they have been involved in the solution of an addition problem by calculation rather than by retrieval. The present study sharpens the current conclusions in the literature and shows that, when the sum of addition problems is up to 10, children mainly use retrieval, but when it is greater than 10, they mainly use calculation procedures.


2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.


Author(s):  
Angela A. Manginelli ◽  
Franziska Geringswald ◽  
Stefan Pollmann

When distractor configurations are repeated over time, visual search becomes more efficient, even if participants are unaware of the repetition. This contextual cueing is a form of incidental, implicit learning. One might therefore expect that contextual cueing does not (or only minimally) rely on working memory resources. This, however, is debated in the literature. We investigated contextual cueing under either a visuospatial or a nonspatial (color) visual working memory load. We found that contextual cueing was disrupted by the concurrent visuospatial, but not by the color working memory load. A control experiment ruled out that unspecific attentional factors of the dual-task situation disrupted contextual cueing. Visuospatial working memory may be needed to match current display items with long-term memory traces of previously learned displays.


Author(s):  
Ian Neath ◽  
Jean Saint-Aubin ◽  
Tamra J. Bireta ◽  
Andrew J. Gabel ◽  
Chelsea G. Hudson ◽  
...  

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