Linn-Kristine Glesnes Ødegaard

In‐flight calibration of NOAA POES proton detectors—Derivation of the MEPED correction factors

The MEPED instruments on board the NOAA POES andMetOp satellites have been continuously measuring energetic particles in the magnetosphere since 1978. However, degradation of the proton detectors over time leads to an increase in the energy thresholds of the instrument and imposes great challenges to studies of long-term variability in the near-Earth space environment as well as a general quantification of the proton fluxes. By comparing monthly mean accumulated integral flux from a new and an old satellite at the same magnetic local time (MLT) and time period, we estimate the change in energy thresholds. The first 12 monthly energy spectra of the new satellite are used as a reference, and the derived monthly correction factors over a year for an old satellite show a small spread, indicating a robust calibration procedure. The method enables us to determine for the first time the correction factors also for the highest-energy channels of the proton detector. In addition, we make use of the newest satellite in orbit (MetOp-01) to find correction factors for 2013 for the NOAA 17 and MetOp-02 satellites. Without taking into account the level of degradation, the proton data from one satellite cannot be used quantitatively for more than 2 to 3 years after launch. As the electron detectors are vulnerable to contamination from energetic protons, the corrected proton measurements will be of value for electron flux measurements too. Thus, the correction factors ensure the correctness of both the proton and electron measurements.

Space Weather impact on the degradation of NOAA POES MEPED proton detectors

The Medium Energy Proton and Electron Detector (MEPED) on board the National Oceanic and Atmospheric Administration Polar Orbiting Environmental Satellites (NOAA POES) is known to degrade with time. In recent years a lot of effort has been put into calibrating the degraded proton detectors. We make use of previous work and show that the degradation of the detectors can be attributed to the radiation dose of each individual instrument. However, the effectiveness of the radiation in degrading the detector is modulated when it is weighted by the mean ap index, increasing the degradation rate in periods with high geomagnetic activity, and decreasing it through periods of low activity. When taking ap and the radiation dose into account, we find that the degradation rate is independent of spacecraft and detector pointing direction. We have developed a model to estimate the correction factor for all the MEPED detectors as a function of accumulated corrected flux and the ap index. We apply the routine to NOAA POES spacecraft starting with NOAA-15, including the European satellites MetOp-02 and MetOp-01, and estimate correction factors.

Energetic electron precipitation into the middle atmosphere—Constructing the loss cone fluxes from MEPED POES

The impact of energetic electron precipitation (EEP) on the chemistry of the middle atmosphere (50-90 km) is still an outstanding question as accurate quantification of EEP is lacking due to instrumental challenges and insufficient pitch angle coverage of current particle detectors. The Medium Energy Proton and Electron Detectors (MEPED) instrument on board the NOAA/Polar Orbiting Environmental Satellites(POES) and MetOp spacecraft has two sets of electron and proton telescopes pointing close to zenith (

Direct and indirect electron precipitation effect on nitric oxide in the polar middle atmosphere, using a full-range energy spectrum

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Energetic electron precipitation in weak to moderate corotating interaction region-driven storms

) and in the horizontal plane (

Nitric Oxide Response to the April 2010 Electron Precipitation Event: Using WACCM and WACCM‐D With and Without Medium‐Energy Electrons

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Atmospheric Drag, Occultation ‘N’ Ionospheric Scintillation (ADONIS) mission proposal - Alpbach Summer School 2013 Team Orange

). Using measurements from either the

Planning Strategies for Mars (Analog) Missions: Real-Time, 3-Days-in-Advance and 1-Day-in-Advance Planning

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Energetic electron precipitation in weak to moderate corotating interaction region-driven storms: EEP IN WEAK TO MODERATE CIR STORMS

or

Direct and indirect electron precipitation effect on nitric oxide in the polar middle atmosphere, using a full-range energy spectrum: DIRECT AND INDIRECT EEP EFFECT ON NO

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