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Article
Open AccessA Uniform Series of Low-Latitude Coronal Holes in 1973–2018
Coronal holes (CHs) are regions in the solar corona characterized by plasma density lower than in the surrounding quiet Sun. Therefore they appear dark in images of the solar atmosphere made, e.g., in extreme ...
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Article
Open AccessNew Homogeneous Dataset of Solar EUV Synoptic Maps from SOHO/EIT and SDO/AIA
Synoptic maps of solar EUV intensities have been constructed for many decades in order to display the distribution of the different EUV emissions across the solar surface, with each map representing one Carrin...
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Article
A New Calibrated Sunspot Group Series Since 1749: Statistics of Active Day Fractions
Although sunspot-number series have existed since the mid-nineteenth century, they are still the subject of intense debate, with the largest uncertainty being related to the “calibration” of the visual acuity ...
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Article
Open AccessThe mass-hierarchy and CP-violation discovery reach of the LBNO long-baseline neutrino experiment
The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, in its first sta...
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Article
Sporadic and recurrent geomagnetic disturbances in 1859–1860 according to the archived data from the Russian network of stations
Based on an analysis of the available archived data from the Russian network of geomagnetic stations, it has been indicated that the known event of August–September 1859 was the first and the greatest event in...
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Article
Fluctuations of cosmic rays and interplanetary magnetic field in the vicinity of interplanetary shock fronts
The spectral characteristic of fluctuations of cosmic rays (CRs) and the interplanetary magnetic field in the prefront region of interplanetary shock waves, where coherent CR fluctuations with energies from ∼1...
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Article
Global Heliospheric Parameters and Cosmic-Ray Modulation: An Empirical Relation for the Last Decades
We study empirical relations between the modulation of galactic cosmic rays quantified in terms of the modulation potential and the following global heliospheric parameters: the open solar magnetic flux, the t...
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Article
Possible planetary excitation of earthquakes
Several recent studies show the possibility of an important connection between the Earths rotational motion and the number of earthquakes (Stavinschi and Souchay 2001, Shanker et al. 2001). We discuss the long...
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Article
Rapid Cosmic Ray Fluctuations: Evidence for Cyclic Behaviour
We study rapid cosmic-ray fluctuations using 5-min resolution data from eight neutron monitors with different cutoff rigidities as well as from the ACE satellite. We define a proxy index of rapid cosmic-ray fl...
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Article
Systematically Asymmetric Heliospheric Magnetic Field: Evidence for a Quadrupole Mode and Non-Axisymmetry with Polarity Flip-Flops
Recent studies of the heliospheric magnetic field (HMF) have detected interesting, systematic hemispherical and longitudinal asymmetries which have a profound significance for the understanding of solar magnet...
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Article
Did Open Solar Magnetic Field Increase During The Last 100 Years? A Reanalysis of Geomagnetic Activity
Long-term geomagnetic activity presented by the aa index has been used to show that the heliospheric magnetic field has more than doubled during the last 100 years. However, serious concern has been raised on the...
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Article
An Upper Limit on Sunspot Activity During the Maunder Minimum
We have estimated the upper and lower limits of sunspot activity, in terms of active day fraction during the Maunder minimum (1645–1710), using raw information on individual daily observations (Hoyt and Schatt...
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Article
Cassini Plasma Spectrometer Investigation
The Cassini Plasma Spectrometer (CAPS) will make comprehensive three-dimensional mass-resolved measurements of the full variety of plasma phenomena found in Saturn’s magnetosphere. Our fundamental scientific g...
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Article
Fluctuations of the Solar Dynamo Observed in the Solar Wind and Interplanetary Magnetic Field at 1 AU and in the Outer Heliosphere
Recent helioseismic observations have found strong fluctuations at a period of about 1.3 years in the rotation speed around the tachocline in the deep solar convection layer. Similar mid-term quasi-periodiciti...
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Article
Long-term longitudinal asymmetries in sunspot activity: Difference between the ascending and descending phase of the solar cycle
We study the longitudinal distribution of sunspot activity in 1917–1995 using vector sums of sunspot areas. The vector sum of sunspots of one solar rotation gives a total vector whose amplitude characterizes t...
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Chapter
Cassini Plasma Spectrometer Investigation
The Cassini Plasma Spectrometer (CAPS) will make comprehensive three-dimensional mass-resolved measurements of the full variety of plasma phenomena found in Saturn’s magnetosphere. Our fundamental scientific g...
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Article
Reconstruction of Monthly and Yearly Group Sunspot Numbers From Sparse Daily Observations
Some periods before 1820 are poorly covered by sunspot observations. In addition to apparent, long observational gaps, there are also periods when there are only few sparse daily sunspot observations during a ...
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Article
Long-Term Solar Cycle Evolution: Review of Recent Developments
The sunspot number series forms the longest directly observed index of solar activity and allows one to trace its variations on the time scale of about 400 years since 1610. This time interval covers a wide ra...
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Article
Mid-term quasi-periodicities in geomagnetic activity during the last 15 solar cycles: Connection to solar dynamo strength – To the memory of Karolen I. Paularena (1957-2001)
Several recent studies have reported quasi-periodicities with a period between 1 and 2 years (to be called here `mid-term quasi-periodicities') in various heliospheric parameters, like solar wind speed, interp...
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Article
Numerical Simulation of the High-Latitude Non-Stationary Ionospheric Alfvén Resonator During an IPDP Event
The ionospheric Alfvén resonator (IAR) was numerically simulated under non-stationary ionospheric and magnetospheric conditions of the IPDP event of December 4, 1986. The full numerical wave method was applied...
