The ESPAS e-infrastructure: Access to data from near-Earth space

doi:10.1051/978-2-7598-1949-2

Cited by 6 publications

(5 citation statements)

References 73 publications

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“…Significant electron precipitation occurs at these latitudes during magnetospheric storms due to increased electron scattering into the bounce loss cone. However, the bounce loss cone at these latitudes is significantly larger than the 30 • field of view of the POES telescopes (Asikainen, 2019;Rodger et al, 2013). This means that the POES 0 • detectors do not resolve fluxes near the edge of the loss cone in the case of partially filled loss cones.…”

Section: Methodsmentioning

confidence: 94%

Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity

et al. 2020

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Abstract. Recently, it has been established that interplanetary coronal mass ejections (ICMEs) can dramatically affect both trapped electron fluxes in the outer radiation belt and precipitating electron fluxes lost from the belt into the atmosphere. Precipitating electron fluxes and energies can vary over a range of timescales during these events. These variations depend on the initial energy and location of the electron population and the ICME characteristics and structures. One important factor controlling electron dynamics is the magnetic field orientation within the ejecta that is an integral part of the ICME. In this study, we examine Van Allen Probes (RBSPs) and Polar Orbiting Environmental Satellites (POESs) data to explore trapped and precipitating electron fluxes during two ICMEs. The ejecta in the selected ICMEs have magnetic cloud characteristics that exhibit the opposite sense of the rotation of the north–south magnetic field component (BZ). RBSP data are used to study trapped electron fluxes in situ, while POES data are used for electron fluxes precipitating into the upper atmosphere. The trapped and precipitating electron fluxes are qualitatively analysed to understand their variation in relation to each other and to the magnetic cloud rotation during these events. Inner magnetospheric wave activity was also estimated using RBSP and Geostationary Operational Environmental Satellite (GOES) data. In each event, the largest changes in the location and magnitude of both the trapped and precipitating electron fluxes occurred during the southward portion of the magnetic cloud. Significant changes also occurred during the end of the sheath and at the sheath–ejecta boundary for the cloud with south to north magnetic field rotation, while the ICME with north to south rotation had significant changes at the end boundary of the cloud. The sense of rotation of BZ and its profile also clearly affects the coherence of the trapped and/or precipitating flux changes, timing of variations with respect to the ICME structures, and flux magnitude of different electron populations. The differing electron responses could therefore imply partly different dominant acceleration mechanisms acting on the outer radiation belt electron populations as a result of opposite magnetic cloud rotation.

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Section: Methodsmentioning

confidence: 94%

Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity

et al. 2020

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“…Note, however, that the data processing used here is based on the raw MEPED data and not on the processing methodology described by Green (2013). The corrections and calibrations introduced to the MEPED measurements have been documented by Asikainen andMursula (2011), Asikainen et al (2012), and Asikainen and Mursula (2013). Figure 1a shows a schematic of a POES satellite orbit along with the directions of SEM-1 and SEM-2 telescopes superposed on the same satellite.…”

Section: Datamentioning

confidence: 90%

“…However, Raben et al (1995) state that the +Y axis would point opposite to the satellite velocity like in SEM-2. In the process of recalculating all auxiliary data (e.g., telescope pitch angles) dependent on satellite location (Asikainen, 2017) both satellite coordinate system definitions were tested. It was found that the original pitch angles stored in the SEM-1 data records are consistent with the Raben et al (1995) definition, which will thus be used here.…”

Section: Datamentioning

confidence: 99%

New Homogeneous Composite Of Energetic Electron Fluxes From POES: 2. Intercalibration of SEM‐1 and SEM‐2

Asikainen

2019

JGR Space Physics

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One of the most popular long‐term data sets of energetic particles used in, for example, long‐term radiation belt studies and in atmospheric/climate studies is perhaps the NOAA/POES (Polar Orbiting Environmental Satellites) data set, which extends nearly continuously from 1979 to present. The present study aims to construct a new homogeneous long‐term composite record of daily latitude distributions of energetic electrons based on the MEPED (Medium Energy Proton and Electron Detector) data. Part 1 of this study corrected the data for temporally varying background noise related to cosmic rays and for the drift in the orientation of satellite orbital planes. The present paper addresses the final and most severe problem for the data homogeneity, caused by the difference of telescope pointing directions in older SEM‐1 and newer SEM‐2 versions of the MEPED instrument. Because the telescope pitch angles and the electron pitch angle distribution change with latitude, the difference in SEM‐1 and SEM‐2 fluxes depends on latitude and varies from time to time. The systematic flux differences between SEM‐1 and SEM‐2 can range between a factor of 1.5 to more than an order of magnitude. Novel statistical methodology based on principal components and canonical correlation mapping is presented here to robustly transform the daily SEM‐1 electron latitude distributions into SEM‐2 level. The data from different POES satellites are then combined into a spatially and temporally homogeneous composite series, which is well suited, for example, for long‐term studies of radiation belts and precipitation related atmospheric ionization and its chemical and dynamical effects in the atmosphere/climate system.

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“…The energetic particle measurements from the MEPED instrument onboard the NOAA/POES satellites currently form the most important long-term data set providing information about precipitation of energetic electrons and protons into Earth's atmosphere. Previous work on this data set has solved many problems related to instrument degradation and calibration and has greatly improved the quality of the data (Asikainen, 2017;Asikainen & Mursula, 2011, 2013Asikainen et al, 2012). Based on these previously corrected energetic electron measurements, we here first composed from each satellite the daily averaged latitude distribution of electrons in three integral energy channels, two nearly orthogonal telescopes, two opposite MLT sectors, and two hemispheres.…”

Section: Discussionmentioning

confidence: 99%

New Homogeneous Composite of Energetic Electron Fluxes From POES Satellites: 1. Correction for Background Noise and Orbital Drift

Asikainen

Ruopsa

2019

JGR Space Physics

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One of the most popular long‐term data sets of energetic particles used in, for example, long‐term radiation belt studies and in atmospheric/climate studies is perhaps the National Oceanic and Atmospheric Administration/Polar Orbiting Environmental Satellites (POES) data set, which extends nearly continuously from 1979 to present. The energetic particle measurements by the Medium Energy Proton and Electron Detector instrument onboard the POES satellites have had many instrumental problems, which have made quantitative estimates of energetic particle fluxes somewhat difficult. However, in the recent years, these instrumental deficiencies have been studied and corrected. Here we aim to construct a new long‐term composite record of energetic electrons based on the Medium Energy Proton and Electron Detector data. In this study we point out that there are also other remaining factors, not related to instrument construction, which still severely impact the overall homogeneity of the 39‐year POES data set. We concentrate here on studying and correcting two issues: (1) temporally varying background noise related to cosmic rays and (2) drift in the orientation of satellite orbital planes, which changes the sampling location of the satellites over time. In particular, we show that the drift of satellite orbital planes leads to rather large changes in the electron fluxes over time, which could be misinterpreted as true temporal changes without the corrections. These changes can be rather large, a factor of 3 or more in the poleward edge of the precipitation zone, and are likely to have a large impact, for example, on atmospheric ionization estimates based on POES data.

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The ESPAS e-infrastructure: Access to data from near-Earth space

Cited by 6 publications

References 73 publications

Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity

Outer Van Allen belt trapped and precipitating electron flux responses to two interplanetary magnetic clouds of opposite polarity

New Homogeneous Composite Of Energetic Electron Fluxes From POES: 2. Intercalibration of SEM‐1 and SEM‐2

New Homogeneous Composite of Energetic Electron Fluxes From POES Satellites: 1. Correction for Background Noise and Orbital Drift

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