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Abstract. Interstellar scintillation multi-frequency observations of PSR 0329+54 in the frequency range from 102 MHz to 5 GHz were analysed to estimate the spectrum of interstellar plasma inhomogeneities in the direction of this pulsar. Based on the theory of diffractive scintillation, the composite structure function of phase fluctuations covering a large range of turbulence scales was constructed. We found that the spectrum is well described by a power law with n = 3.5 for scales from 10 6 to 10 9 m, which differs from the value known for a Kolmogorov spectrum. We can, however, within the accuracy of our data not exclude a Kolmogorov spectrum. It became also clear that angular refraction of emission must be taken into account to fit the data points at all observing frequencies. The size of the irregularities responsible for the angular refraction is estimated to be about 3 × 10 13 m. They can be identified with clouds of neutral hydrogen that can be considered as holes of electron density.

We report the results of a multi-instrument, multi-technique, coordinated study of the solar eruptive event of 13 May 2005. We discuss the resultant Earth-directed (halo) coronal mass ejection (CME), and the effects on the terrestrial space environment and upper Earth atmosphere. The interplanetary CME (ICME) impacted the Earth's magnetosphere and caused the most-intense geomagnetic storm of 2005 with a Disturbed Storm Time (Dst) index reaching −263 nT at its peak. The terrestrial environment responded to the storm on a global scale. We have combined observations and measurements from coronal and interplanetary remote-sensing instruments, interplanetary and near-Earth in-situ measurements, remote-sensing observations and in-situ measurements of the terrestrial magnetosphere and ionosphere, along with coronal and heliospheric modelling. These analyses are used to trace the origin, development, propagation, terrestrial impact, and subsequent consequences of this event to obtain the most comprehensive view of a geo-effective solar eruption to date. This particular event is also part of a NASA-sponsored Living With a Star (LWS) study and an on-going US NSF-sponsored Solar, Heliospheric, and INterplanetary Environment (SHINE) community investigation.

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