Measurement of Individual H+ and O+ Ion Temperatures in the Topside Ionosphere
Abstract
Plasma temperatures in the ionosphere are associated with both the dynamics and spatial distribution of the neutral and charge particles. During the daytime, temperatures are determined by solar energy inputs and energy exchange between charged and neutral particles. Plasma transport parallel to the magnetic field adds another influence on temperatures through adiabatic processes that are most evident during the nighttime. Previous observations suggest that the topside H+ temperature (TH+) should reside between the O+ temperature (TO+) and the electron temperature (Te), and further calculations confirm the preferential heat transfer from the electrons to H+ in the topside. In this work we implement a more sophisticated analysis procedure to extract individual mass‐dependent ion temperatures from the retarding potential analyzer measurements on the DMSP F15 satellite. The results show that the daytime TH+ is a few hundred degrees higher than TO+ at all longitudes. The nighttime temperature difference between TH+ and TO+ is indicative of mass‐dependent adiabatic heating and cooling processes across the equatorial region. The ion temperatures and measured plasma flows present clear longitudinal variations that are associated with magnetic declination.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 01, 2018
- Source ID
- 10.1002/2017ja024932
Entities
People
- Chih‐Te Hsu
- Roderick A. Heelis
Organizations
- Air Force Office of Scientific Research
- National Aeronautics and Space Administration
- University of Texas at Dallas