Elemental and charge state composition of the fast solar wind observed with SMS instruments on WIND
Abstract
The elemental composition and charge state distributions of heavy ions of the solar wind provide essential information about: (1) atom-ion separation processes in the solar atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the solar wind compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the solar wind. This information is required for solar wind acceleration models. The SWICS instrument on Ulysses measures for all solar wind flow conditions the relative abundance of about 8 elements and 20 charge states of the solar wind. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the solar wind from the polar coronal holes near solar minimum conditions. The MASS instrument on the WIND spacecraft is a high-mass resolution solar wind ion mass spectrometer that will provide routinely not only the abundances and charge state of all elements easily measured with SWICS, but also of N, Mg, S. The MASS sensor was fully operational at the end of 1994 and has sampled the in-ecliptic solar wind composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on WIND allows us to view for the first time the solar wind from two regions of the large coronal hole. Observations with SWICS in the coronal hole wind: (1) indicate that the FIP effect is small; and (2) allow us determine the altitude of the maximum in the electron temperature profile, and indicate a maximum temperature of approximately 1.5 MK. New results from the SMS instruments on Wind will be compared with results from SWICS on Ulysses.
- Publication:
-
Solar Wind Eight
- Pub Date:
- June 1995
- Bibcode:
- 1995sowi.conf...35G
- Keywords:
-
- Charge Distribution;
- Charged Particles;
- Solar Wind;
- Solar Atmosphere;
- Photosphere;
- Solar Wind Velocity;
- Atmospheric Composition;
- Solar Physics;
- Sun;
- Atmospheric Temperature;
- Heavy Ions;
- Atmospheric Heating;
- Abundance;
- Scientific Satellites;
- Synchronous Meteorological Satellite;
- Mass Spectrometers;
- Particle Interactions;
- Temperature Profiles;
- Solar Activity Effects;
- Wind Direction;
- Solar Physics