scholarly journals Long-term magnetic field stability of Vega

2012 ◽  
Author(s):  
D. Alina ◽  
P. Petit ◽  
F. Lignières ◽  
G. A. Wade ◽  
R. Fares ◽  
...  
Keyword(s):  
Magnetic Field

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

scholarly journals Long-term evolution of the heliospheric magnetic field inferred from cosmogenic 44Ti activity in meteorites

2018 ◽  
Vol 610 ◽  
pp. A28 ◽  
Author(s):  
S. Mancuso ◽  
C. Taricco ◽  
P. Colombetti ◽  
S. Rubinetti ◽  
N. Sinha ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ice Cores ◽  
Long Term Evolution ◽  
Galactic Cosmic Rays ◽  
Sunspot Activity ◽  
Cosmogenic Isotopes ◽  
Heliospheric Magnetic Field ◽  
The Past ◽  
Term Evolution

Typical reconstructions of historic heliospheric magnetic field (HMF) BHMF are based on the analysis of the sunspot activity, geomagnetic data or on measurement of cosmogenic isotopes stored in terrestrial reservoirs like trees (14C) and ice cores (10Be). The various reconstructions of BHMF are however discordant both in strength and trend. Cosmogenic isotopes, which are produced by galactic cosmic rays impacting on meteoroids and whose production rate is modulated by the varying HMF convected outward by the solar wind, may offer an alternative tool for the investigation of the HMF in the past centuries. In this work, we aim to evaluate the long-term evolution of BHMF over a period covering the past twenty-two solar cycles by using measurements of the cosmogenic 44Ti activity (τ1∕2 = 59.2 ± 0.6 yr) measured in 20 meteorites which fell between 1766 and 2001. Within the given uncertainties, our result is compatible with a HMF increase from 4.87-0.30+0.24 nT in 1766 to 6.83-0.11+0.13 nT in 2001, thus implying an overall average increment of 1.96-0.35+0.43 nT over 235 years since 1766 reflecting the modern Grand maximum. The BHMF trend thus obtained is then compared with the most recent reconstructions of the near-Earth HMF strength based on geomagnetic, sunspot number, and cosmogenic isotope data.

Search for long term variations of the interplanetary magnetic field

Solar Physics ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 241-254 ◽  
Author(s):  
F. Mariani ◽  
L. Diodato ◽  
G. Moreno
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Long Term Variations

scholarly journals Repeat station data compared to a global geomagnetic field model

2013 ◽  
Vol 55 (6) ◽  
Author(s):  
Monika Korte ◽  
Vincent Lesur
Keyword(s):  
Magnetic Field ◽  
Secular Variation ◽  
Global Model ◽  
Time Interval ◽  
Night Time ◽  
Core Field ◽  
Repeat Station ◽  
Station Data ◽  
Long Term Trends

<p>Geomagnetic repeat station surveys with local variometers for improved data reductions have been carried out in Germany for about ten years. For nearly the same time interval the satellites Ørsted and CHAMP have provided a good magnetic field data coverage of the whole globe. Recent global field models based on these satellite data together with geomagnetic observatory data provide an improved description of the core field and secular variation. We use the latest version of the GFZ Reference Internal Magnetic Model to compare the magnetic field evolution predicted by that model between 2001 and 2010 to the independent repeat station data collected over the same time interval in Germany. Estimates of crustal bias at the repeat station locations are obtained as averages of the residuals, and the scatter or trend around each average provides information about influences in the data from field sources not (fully) described by the global model. We find that external magnetic field signal in the order of several nT, including long-term trends, remains both in processed annual mean and quiet night time repeat station data. We conclude that the geomagnetic core field secular variation in this area is described to high accuracy (better than 1 nT/yr) by the global model. Weak long-term trends in the residuals between repeat station data and the model might indicate induced lithospheric anomalies, but more data are necessary for a robust analysis of such signals characterized by very unfavorable signal-to-noise ratio.</p>

scholarly journals Long-term Evolution of the Sun’s Magnetic Field during Cycles 15–19 Based on Their Proxies from Kodaikanal Solar Observatory

2020 ◽  
Vol 902 (1) ◽  
pp. L15
Author(s):  
Alexander V. Mordvinov ◽  
Bidya Binay Karak ◽  
Dipankar Banerjee ◽  
Subhamoy Chatterjee ◽  
Elena M. Golubeva ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Long Term Evolution ◽  
Solar Observatory ◽  
Term Evolution

scholarly journals Practice and perspectives of using ultrasensitive magnetometers in biomedical research.

2021 ◽  
Author(s):  
Yu.V. Maslennikov ◽  
◽  
◽  
Keyword(s):  
Magnetic Field ◽  
Biomedical Research ◽  
Magnetic Measurements ◽  
Signal To Noise Ratio ◽  
Frequency Range ◽  
Optically Pumped ◽  
Technical Solutions ◽  
Further Development ◽  
The Magnetic Field

There are a large number of sensors for measuring the magnetic field of biological objects. They are characterized by the type of the measured physical parameter (magnetic field strength, magnetic flux, etc.), the level of intrinsic sensitivity, and the frequency range of the recorded signals. The long-term practice of studying biomagnetic signals shows that only SQUID-based magnetometers and optically pumped magnetometers have sensitivity levels sufficient for recording biomagnetic signals with the required signal-to-noise ratio. This chapter reflects the main directions of using such magnetometers and methods of magnetic measurements in biomedical research, gives examples of existing technical solutions, and shows possible ways of their further development.

EFFECT OF ATTENUATED MAGNETIC FIELD ON DEVELOPMENT OF THE LIVER AND SPLEEN IN EMBRYONIC JAPANESE QUAIL

2021 ◽  
Vol 55 (6) ◽  
pp. 50-55
Author(s):  
S.A. Pineguin ◽  
◽  
O.A. Dadasheva ◽  
E.I. Mednikova ◽  
O.A. Grushina ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Japanese Quail ◽  
First Generation ◽  
Space Missions ◽  
The Moon ◽  
Living Organisms ◽  
The Magnetic Field

Expectation of remote space missions and long-term stay and work on the Moon with the magnetic field 1,000 times weaker than on Earth sets the researchers the formidable task to investigate effects of the hypomagnetic environment on living organisms. The paper reports data about the liver and spleen development in Japanese quail embryos of various age exposed in a modeled lunar magnetic field. Retardation of hemopoiesis was observed as in the first generation embryos (F1), so in sequential embryo generations developed in the ordinary magnetic environment (F2).

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