3D-POC - 3D Properties of Coronal Mass Ejections

The 3D-POC study is designed to exploit the unprecedented capabilities of the NASA Solar Terrestrial Relations Observatory (STEREO) to better understand the physical processes and propagation characteristics of solar CMEs. CMEs are the main driver of major disturbances of our "space weather".

Short Description

Our Sun is an active star and its most violent activity phenomena are flares and coronal mass ejections (CMEs). Flares and CMEs are closely related phenomena and can cause severe perturbations of our "space weather", i.e. the conditions in our near-Earth space environment. The effects of this solar activity are manifold and include delightful northern lights, increased radiation for manned space missions and aircraft passengers, failures in spacecraft navigation/communication systems as well as blackouts of power plants on the ground. Due to the increased need and economic dependence on space technology improving the knowledge of our space environment and forecasting our space weather are becoming ever more relevant issues.

The STEREO mission consists of two Sun-orbiting spacecraft (STEREO-A and STEREO-B) with identical instrument suites observing the solar corona and heliosphere from two different vantage points. This makes it possible for the first time to reconstruct the three- dimensional (3D) geometry and 3D propagation characteristics of coronal mass ejections, which are essential in evaluating if and when a CME erupting from the Sun may hit Earth.

The 3D-POC project provides the first statistical study on the following decisive 3D properties of CMEs:

  • The 3D propagation parameters of CMEs (directivity, kine- matics, velocity)
  • The "true" mass of CMEs as derived from the 3D recon- structions

The questions addressed in this study are crucially important for better understanding and modelling the propagation of CMEs from the Sun to the Earth, and thus to better forecast the CME’s arrival time, velocity, and impact on our "space weather".

Project Partners


University of Graz, Institute of Physics - Manuela Temmer


  • Naval Research Laboratory, USA, Space Science Division - Angelos Vourlidas
  • University of Zagreb, Croatia, Hvar Observatory - Bojan Vrsnak

Contact Address

University of Graz
Institute of Physics
Manuela Temmer
Universitätsplatz 5
A-8010 Graz
Tel.: +43 (316) 380 - 8610
E-mail: manuela.temmer@uni-graz.at
Web: www.uni-graz.at/