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Energy Input from the Exterior Cusp into the Ionosphere: Correlated Ground-Based and Satellite Observations. Yordanova, E. , D. Sundkvist, S. C. Buchert, M. André, Y. Ogawa, M. Morooka, O. Margithu, O. Amm, A. N. Fazakerley, and H. Réme. GRL, 34, L04102, doi:10.1029/2006GL028617.
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Energy Input from the Exterior Cusp into the Ionosphere: Correlated Ground-Based and Satellite Observations Yordanova, E., D. Sundkvist, S. C. Buchert, M. André, Y. Ogawa, M. Morooka, O. Margithu, O. Amm, A. N. Fazakerley, and H. Réme GRL, 34, L04102, doi:10.1029/2006GL028617
February 1, 2002 cusp event • Cluster position in the Tsyganenko 2001 model. • Cluster magnetic footprints with the location of the EISCAT Svalbard radar and MIRACLE magnetometers at the ground-based stations NAL, LYR, HOR and HOP.
EISCAT observations (a) electron density; (b) electron temperature; (c) ion temperature; (d) energy flux
Estimation of the energy flux in the F-region of the ionospheric cusp • Integration over altitudes (250-600 km) of the cooling rates of the electrons due to elastic and inelastic processes: • Coulomb collisions of electrons with ambient ions; • elastic collisions of electrons with neutrals; • rotational and vibrational excitations of molecular neutrals; • fine structure excitation of the atomic oxygen; • excitation of the lowest electronic state of the atomic oxygen.
Cluster observations • electron differential energy spectrogram (spacecraft 3). • ion differential energy spectrogram; • up- and downgoing (positive, earthward) electron energy flux • up- and downgoing ion energy flux, • the GSE components of the electric field ; • the GSE components (in colors) of the magnetic field
, where (EISCAT) Estimation of the Joule heating in the ionosphere technique of 2D upward continuation based on magnetometers data (MIRACLE)
The Poynting flux on Cluster - positive toward the Earth; • downgoing electron energy flux (spacecraft 1-4); • downgoing ion energy flux (spacecraft 1 and 3); • total particle energy flux (spacecraft 1 and 3) and EISCAT energy input; • (e) equivalent ionospheric current density (MIRACLE); • (f) height--integrated Pedersen and Hall conductivities (EISCAT); • (g) ionospheric electric field strength; • (h) the 1-minute averaged Poynting flux and the Joule heating Results
Conclusions: • the direct magnetosheath soft plasma precipitation into the ionosphere is responsible for the heating of the F-region of the cusp. • more than enough Poynting flux for the heating of the E-region of the cusp (part of it goes to the Joule heating, the other pars may cause other phenomena).