Kosch, M.J. and Yiu, I. and Anderson, C. and Tsuda, T. and Ogawa, Y. and Nozawa, S. and Aruliah, A. and Howells, V. and Baddeley, L.J. and McCrea, I.W. and Wild, J.A. (2011) Mesoscale observations of Joule heating near an auroral arc and ion-neutral collision frequency in the polar cap E region. Journal of Geophysical Research, 116 (A05321). pp. 1-16. ISSN 0148-0227
Abstract
We report on the first mesoscale combined ionospheric and thermospheric observations, partly in the vicinity of an auroral arc, from Svalbard in the polar cap on 2 February 2010. The EISCAT Svalbard radar employed a novel scanning mode in order to obtain F and E region ion flows over an annular region centered on the radar. Simultaneously, a colocated Scanning Doppler Imager observed the E region neutral winds and temperatures around 110 km altitude using the 557.7 nm auroral optical emission. Combining the ion and neutral data permits the E region Joule heating to be estimated with an azimuthal spatial resolution of ∼64 km at a radius of ∼163 km from the radar. The spatial distribution of Joule heating shows significant mesoscale variation. The ion-neutral collision frequency is measured in the E region by combining all the data over the entire field of view with only weak aurora present. The estimated ion-neutral collision frequency at ∼113 km altitude is in good agreement with the MSIS atmospheric model.