Observations and Validation of Plasma Density, Temperature, and O+ Abundance From a Langmuir Probe Onboard the International Space Station. Issue 10 (18th October 2021)

• Record Type: Journal Article
• Authors: Debchoudhury, Shantanab; Barjatya, Aroh; Minow, Joseph I.; Coffey, Victoria N.; Chandler, Michael O.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-18
• Subjects: Langmuir probes -- ionosphere -- data analysis -- electron density -- electron temperature -- O+ percentage; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2021JA029393
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: The Floating Potential Measurement Unit (FPMU) has been operational on board the International Space Station (ISS) since 2006. One of the instruments in the FPMU suite is a spherical wide‐sweeping Langmuir probe, referred to as the WLP, which is sampled at a temporal cadence of 1 s giving in‐situ measurements of the plasma density and electron temperature. In this study we present our refinements to the Langmuir probe analysis algorithm that address the uncertainties associated with photoelectron emission current from the metal probe. We also derive the fraction of O + ions as a secondary data product, which shows decrease in O + abundance in the post‐midnight sector during solar minimum. The derived plasma parameters are compared and validated with an independent in‐situ measurement technique, overlapping ground‐based incoherent scatter radar measurements, as well as International Reference Ionosphere model output. The reduced data set spans the entire solar cycle 24 and shows the F‐region ionosphere variance at ISS altitudes. Key Points: Langmuir probe measurements of plasma parameters in Earth's F‐region ionosphere over Solar Cycle 24 Reduced parameters include plasma density, electron temperature, and O + fraction which are validated using plasma impedance probe and Incoherent Scatter Radar observations Algorithm details of analyzing a Langmuir probe IV curve in ionospheric space plasma are provided