HR: 0800h
AN: SH22A-0851    [Abstracts]
TI: Ulysses 2007 Fast Latitude Scan : Radio Observations of High-Speed Solar Wind Electron Parameters Near Solar Minimum
AU: * Issautier, K
EM: karine.issautier@obspm.fr
AF: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, Meudon, 92195, France
AU: Le Chat, G
EM: gaetan.lechat@obspm.fr
AF: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, Meudon, 92195, France
AU: Meyer-Vernet, N
EM: nicole.meyer@obspm.fr
AF: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, Meudon, 92195, France
AU: Moncuquet, M
EM: michel.moncuquet@obspm.fr
AF: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, Meudon, 92195, France
AU: Hoang, S
EM: sang.hoang@obspm.fr
AF: LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 5 place Jules Janssen, Meudon, 92195, France
AB: Ulysses spacecraft gives a unique opportunity to study continuously the stationary and steady-state high-speed wind out of the ecliptic plane and its large-scale variations during a whole solar cycle. The fast pole-to-pole transit in 1994-1995 has allowed us to make an accurate in situ diagnostics of the electron plasma parameters at high-latitude near solar minimum, using the quasi-thermal noise spectroscopy method on the URAP radio receiver. In particular, we have accurately obtained the radial profile of the electron density and temperature in the fast wind without data selection in contrast to ecliptic observations where different types of winds have to be sorted out. The electron thermal temperature profile behaves between adiabatic and isothermal, in qualitative agreement with a simple kinetic collisionless model. Since February 2007, Ulysses is performing its second high latitude exploration at solar activity minimum, the magnetic field of the Sun being reversed compared to the previous solar minimum. We will present electron measurements acquired in the southern polar coronal hole in 2007 using the quasi-thermal noise method. We will compare these results to high latitude observations performed during the previous solar activity minimum, which may constraint models on the 3-D structure of the solar wind over the solar cycle.
DE: 0654 Plasmas
DE: 2164 Solar wind plasma
DE: 2194 Instruments and techniques
DE: 7511 Coronal holes
DE: 7536 Solar activity cycle (2162)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting