Articles | Volume 32, issue 5
Ann. Geophys., 32, 499–506, 2014
Ann. Geophys., 32, 499–506, 2014

Regular paper 20 May 2014

Regular paper | 20 May 2014

First negative system of N2+ in aurora: simultaneous space-borne and ground-based measurements and modeling results

K. Axelsson1,2, T. Sergienko1, H. Nilsson1, U. Brändström1, K. Asamura3, and T. Sakanoi4 K. Axelsson et al.
  • 1Swedish Institute of Space Physics, Kiruna, Sweden
  • 2Division of Space Technology, Luleå University of Technology, Kiruna, Sweden
  • 3Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, Japan
  • 4Planetary Plasma and Atmospheric Research Center, Graduate School of Science,Tohoku University, Aramaki, Aoba, Sendai, Japan

Abstract. The auroral emission of the first negative system of N2+ at 427.8 nm is analyzed using simultaneous measurements from the ground with ALIS (Auroral Large Imaging System) and from space with optical (MAC) and particle (ESA) instruments of the Reimei satellite. The study has two main objectives. The first is validation of the absolute calibration of the ALIS and the Reimei MAC cameras. The other task is to evaluate different cross sections of the electron excitation of N2+ that are used for the modeling of the auroral 1N system emissions. The simultaneous measurements of the 427.8 nm emission by ALIS and Reimei imagers show excellent agreement, indicating that the calibration of the two instruments is correct. Comparison of the 427.8 nm emission intensity calculated using the incident electron flux measured by the Reimei particle instruments with intensities measured by the optical imagers show that the best match is reached with the cross section from Shemansky and Liu (2005).