Abstracts submitted by Stefaan Poedts

The new plans of the European SPS Board

Stefaan Poedts

CPA, K.U.Leuven

The SPS Board has ambitious plans and submitted a FP7 Coordination Action proposal concerning "Solar and Space Environment" sciences. This proposal is aimed at complementing the related efforts in this respect by other key players, including ESA. The contribution of ESSENCE in this field would be the coordination of integrated and coherent activities, avoiding duplications and maximizing interoperability, and the identification of common objectives and the most optimal opportunities for EU funding. European industry will also be involved through the foreseen collaboration with NAVOBS+.

The project integrates the coordination entities JOSO and CESRA and the experts team SWWT to establish a more coherent and clearer structure. In this way, we want to keep the overview and to re-structure, re-organize and develop the solar and space environment science community. This new organization structure will thus create a European equivalent of the American SPD that can and will collaborate with the SPD as an independent equal partner.

The new structure will enable us also to identify the areas that are most suitable for collaborations with the SPD and likewise organizations, to specify areas in which the EU should proceed independently, and to identify the areas best suited for EU funding complementary to the ESA science programme
Ionospheric Height changes due to Space Weather phenomena

Alexander Soenen[1], Stefaan Poedts[1], Martin Füllekrug[2]

[1] Centrum voor Plasma-Astrofysica, K.U.Leuven; [2]University of Bath, UK

This project looked at how the ionospheric height varied over the period of a solar cycle and found that the ionospheric height varies by as much as 2km between solar minimum and solar maximum. The project also found that a diurnal variation can be observed in the intensity of Very Low Frequency radio waves. The intensity decreased soon after sunrise, due to the increased interaction with the ionosphere, and increased again soon after sunset. The final stages of this project involved trying to detect the difference between electrons accelerated directly by the Sun and those accelerated by mechanisms within the solar wind. No conclusive evidence was found to support this idea but the detailed analysis used lead to some interesting observations on particle effects. The particle effect on the ionospheric height with regards to the solar rotational period was therefore studied; a subject not yet covered in any major scientific research papers. A solar rotational effect of ± 28 days was observed in the particle data with a substantial decrease in ionospheric height detected. Further research is required to determine whether this can be attributed to either protons or electrons.
Magnetic Field Disturbances Around a Super-Sonic Interplanetary Magnetic Cloud

E. Romashets [1], M. Vandas [2] and S. Poedts [3]

[1] Prairie View A & M University, TX 77446 USA [2] Astronomical Institute, Academy of Sciences of the Czech Republic [3] CPA, K.U.Leuven, Leuven, Belgium

It is widely accepted that interplanetary magnetic clouds can cause strong geomagnetic storms due to the high magnetic field magnitude in their interior, especially if the magnetic field has a large negative B_z component. Also, disturbances around such objects can play an important role. The magnetic and flow fields in the sheath
region in front of the body and in the rear of the cloud are important for understanding the dynamics and evolution of the interplanetary cloud, but also for the geo-efficiency of the cloud impact.

The aim of the present contribution is to calculate magnetic field in this sheath region in order to evaluate the possible geo-efficiency of this region in terms of the maximum B_z-component in this region. To describe the magnetic field between the bow shock surface and the cloud's boundary, we consider the disturbed field around the body as given by a vector potential. All three components of the vector potential are expressed as analytical functions. We present the magnetic field distribution in the sheath region in front of the body and in the rear of the cloud for two sample cases, viz. one case with a uniform ambient magnetic field and another case with an ambient spiral field similar to the Parker spiral field in the inner heliosphere.