Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements
Abstract We calibrate the Swarm Langmuir Probe Ion Drift, Density and Effective Mass (SLIDEM) products using the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC‐1) electron density measurements. SLIDEM combines electric current measurements from the Electric Field Inst...
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| Format: | Article |
| Language: | English |
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American Geophysical Union (AGU)
2024-03-01
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| Series: | Earth and Space Science |
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| Online Access: | https://doi.org/10.1029/2023EA003463 |
| _version_ | 1797218185691267072 |
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| author | Johnathan K. Burchill Levan Lomidze |
| author_facet | Johnathan K. Burchill Levan Lomidze |
| author_sort | Johnathan K. Burchill |
| collection | DOAJ |
| description | Abstract We calibrate the Swarm Langmuir Probe Ion Drift, Density and Effective Mass (SLIDEM) products using the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC‐1) electron density measurements. SLIDEM combines electric current measurements from the Electric Field Instrument faceplate (situated on the ram‐facing side of the satellite) with ion admittance measurements from a spherical Langmuir probe to estimate ionospheric ion density, bulk ion drift parallel to the satellite trajectory in the polar regions, and effective ion mass at low and middle latitudes. SLIDEM processing includes an eight‐parameter empirical geometry model that expresses the corrections to the effective faceplate area and spherical probe radius arising from satellite‐plasma interactions. Validation of SLIDEM density by conjunctions with COSMIC density altitude profiles reveals systematic errors, with SLIDEM underestimating corresponding COSMIC data by around 10%. Using the same conjunctions to calibrate the SLIDEM density processor, a simple one‐parameter geometry model is obtained, which significantly reduces bias in ion density. This leads to reduced bias in the ion ram speed and in the effective mass, both of which are more consistent with empirical ionospheric models. We examined three models characterizing the variation of probe effective electrode current collection areas. Faceplate geometries are statistically indistinguishable from the physical faceplate cross section. Spherical Langmuir probe radius is effectively reduced by about 10% due to satellite‐plasma interactions. We recommend updating the SLIDEM processor to use a smaller value for the spherical probe's radius. |
| first_indexed | 2024-04-24T12:13:44Z |
| format | Article |
| id | doaj.art-8f465061573e433dbb11adee55eff538 |
| institution | Directory Open Access Journal |
| issn | 2333-5084 |
| language | English |
| last_indexed | 2024-04-24T12:13:44Z |
| publishDate | 2024-03-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Earth and Space Science |
| spelling | doaj.art-8f465061573e433dbb11adee55eff5382024-04-08T08:47:01ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842024-03-01113n/an/a10.1029/2023EA003463Calibration of Swarm Ion Density, Drift, and Effective Mass MeasurementsJohnathan K. Burchill0Levan Lomidze1Department of Physics and Astronomy University of Calgary Calgary AB CanadaDepartment of Physics and Astronomy University of Calgary Calgary AB CanadaAbstract We calibrate the Swarm Langmuir Probe Ion Drift, Density and Effective Mass (SLIDEM) products using the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC‐1) electron density measurements. SLIDEM combines electric current measurements from the Electric Field Instrument faceplate (situated on the ram‐facing side of the satellite) with ion admittance measurements from a spherical Langmuir probe to estimate ionospheric ion density, bulk ion drift parallel to the satellite trajectory in the polar regions, and effective ion mass at low and middle latitudes. SLIDEM processing includes an eight‐parameter empirical geometry model that expresses the corrections to the effective faceplate area and spherical probe radius arising from satellite‐plasma interactions. Validation of SLIDEM density by conjunctions with COSMIC density altitude profiles reveals systematic errors, with SLIDEM underestimating corresponding COSMIC data by around 10%. Using the same conjunctions to calibrate the SLIDEM density processor, a simple one‐parameter geometry model is obtained, which significantly reduces bias in ion density. This leads to reduced bias in the ion ram speed and in the effective mass, both of which are more consistent with empirical ionospheric models. We examined three models characterizing the variation of probe effective electrode current collection areas. Faceplate geometries are statistically indistinguishable from the physical faceplate cross section. Spherical Langmuir probe radius is effectively reduced by about 10% due to satellite‐plasma interactions. We recommend updating the SLIDEM processor to use a smaller value for the spherical probe's radius.https://doi.org/10.1029/2023EA003463SwarmSLIDEMionospheric densityion driftion compositionCOSMIC |
| spellingShingle | Johnathan K. Burchill Levan Lomidze Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements Earth and Space Science Swarm SLIDEM ionospheric density ion drift ion composition COSMIC |
| title | Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements |
| title_full | Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements |
| title_fullStr | Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements |
| title_full_unstemmed | Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements |
| title_short | Calibration of Swarm Ion Density, Drift, and Effective Mass Measurements |
| title_sort | calibration of swarm ion density drift and effective mass measurements |
| topic | Swarm SLIDEM ionospheric density ion drift ion composition COSMIC |
| url | https://doi.org/10.1029/2023EA003463 |
| work_keys_str_mv | AT johnathankburchill calibrationofswarmiondensitydriftandeffectivemassmeasurements AT levanlomidze calibrationofswarmiondensitydriftandeffectivemassmeasurements |