2011 SuperDARN Workshop
Sounding rocket measurements of decameter structures in the cusp
K. Oksavik (1), J. Moen (1,2), D.A. Lorentzen (1), F. Sigernes (1), T. Abe (3), Y. Saito (3), and M. Lester (4)
(1) The University Centre in Svalbard, Longyearbyen, Norway
(2) Department of Physics, University of Oslo, Oslo, Norway
(3) Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan
(4) Department of Physics & Astronomy, University of Leicester, Leicester, U.K.
abstract. In this paper we use in-situ measurements from a sounding rocket to investigate the fine-scale structures in polar cap patches and the growth of F-region plasma irregularities in the cusp ionosphere. The Investigation of Cusp Irregularities (ICI-2) sounding rocket was launched from Ny-??esund, Svalbard, on 05 December 2008. The high-resolution rocket data is combined with ground-based data; an all-sky camera, the EISCAT Svalbard Radar, and the SuperDARN Hankasalmi radar. These datasets are used to characterize the spatial structure of the observed F-region irregularities and to derive instability growth rates at various spatial scales. We find the gradient-drift (GD) mechanism to be dominating the production of the observed F-region irregularities. The growth rate of the Kelvin-Helmholtz (KH) mechanism was too slow to explain any of the observed plasma irregularities.