Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind

Karine Issautier (1, 2, 3) , Claude Perche (1, 2, 3) , Sang Hoang (1, 2, 3) , Catherine Lacombe (1, 2, 3) , Milan Maksimovic (1, 2, 3) , Jean-Louis Bougeret (1, 2, 3) , C. Salem (4)

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 Ingénieurs, Techniciens et Administratifs
3 Physique des plasmas
4 SSL - Space Sciences Laboratory [Berkeley]

We present the solar wind plasma parameters obtained from the Wind spacecraft during more than nine years, encompassing almost the whole solar cycle 23. Since its launch in November 1994 Wind has frequently observed the in-ecliptic solar wind upstream of the Earth's bow shock. The WIND/WAVES thermal noise receiver was specially designed to measure the in situ plasma thermal noise spectra, from which the electron density and temperature can be accurately determined. We present and discuss histograms of such measurements performed from 1994 to 2003. Using these large data sets, we study the density and core temperature variations with solar activity cycle and with different regimes of the solar wind. We confirm the anticorrelation of the electron density with the sunspot number, and obtain a positive correlation of the core temperature, with the sunspot number.

Domaines: Astrophysique [astro-ph]

Karine Issautier, Claude Perche, Sang Hoang, Catherine Lacombe, Milan Maksimovic, et al.. Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind. Advances in Space Research, 2005, 35, pp.2141-2146. ⟨10.1016/j.asr.2005.04.085⟩. ⟨hal-03732758⟩