98 citations · 98 across the 1 of their papers we have counts for
5 papers
A solar cycle lost in 1793--1800: Early sunspot observations resolve the old mystery
Ilya G. Usoskin, Kalevi Mursula, Rainer Arlt +1
Because of the lack of reliable sunspot observation, the quality of sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784--1799)…
Did Open Solar Magnetic Field Increase during the Last 100 Years: A Reanalysis of Geomagnetic Activity
K. Mursula, D. Martini, A. Karinen
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, seriou…
Systematically Asymmetric Heliospheric Magnetic Field: Evidence for a Quadrupole Mode and Non-axisymmetry with Polarity Flip-flops
K. Mursula, T. Hiltula
Recent studies of the heliospheric magnetic field (HMF) have detected interesting, systematic hemispherical and longitudinal asymmetries which have a profound significance for the…
A Millennium Scale Sunspot Number Reconstruction: Evidence For an Unusually Active Sun Since the 1940's
Ilya G. Usoskin, Sami K. Solanki, Manfred Schuessler +2
The extension of the sunspot number series backward in time is of considerable interest for dynamo theory, solar, stellar, and climate research. We have used records of the Be-10 c…
Reconstruction of solar activity for the last millennium using Be data
I. G. Usoskin, K. Mursula, S. Solanki +2
In a recent paper (Usoskin et al., 2002a), we have reconstructed the concentration of the cosmogenic Be isotope in ice cores from the measured sunspot numbers by using physi…