Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation
Abstract In this work we enable the data assimilation algorithm Estimating Model Parameters from Ionospheric Reverse Engineering (EMPIRE) to estimate global neutral winds. EMPIRE corrects the ion drifts and neutral winds from background models using electron density in the F region derived mainly fr...
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| Format: | Article |
| Language: | English |
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Wiley
2022-08-01
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| Series: | Space Weather |
| Online Access: | https://doi.org/10.1029/2022SW003052 |
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| _version_ | 1841536481832730624 |
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| author | Aurora López Rubio Seebany Datta‐Barua |
| author_facet | Aurora López Rubio Seebany Datta‐Barua |
| author_sort | Aurora López Rubio |
| collection | DOAJ |
| description | Abstract In this work we enable the data assimilation algorithm Estimating Model Parameters from Ionospheric Reverse Engineering (EMPIRE) to estimate global neutral winds. EMPIRE corrects the ion drifts and neutral winds from background models using electron density in the F region derived mainly from total electron content measurements. The new EMPIRE basis functions for the neutral winds are vector spherical harmonics, enforcing the field to be smooth and continuous globally. Global basis functions allow us to estimate the horizontal wind vector from time‐varying plasma densities. The geomagnetic storm on 25 October 2011 is studied to investigate the global implementation of neutral wind estimation. During this storm, the estimates are also compared to those of the old method of estimation using power series and to Fabry‐Perot interferometer (FPI) measurements for validation at three different sites: Pisgah, Cariri, and Nasca. The new global estimation is 10%–20% closer to the FPI measurements than the model and than the old method for most of the viewing directions of the sites, in terms of root‐mean‐square residuals. In the northward direction at Pisgah the estimates using either the old or new implementation disagree with the model, and might be related to an insufficiently small temporal scale used in EMPIRE. |
| format | Article |
| id | doaj-art-51ecc53647344bcfb2c4ee8d01995173 |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2022-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-51ecc53647344bcfb2c4ee8d019951732025-01-14T16:27:07ZengWileySpace Weather1542-73902022-08-01208n/an/a10.1029/2022SW003052Vector Spherical Harmonics for Data‐Assimilative Neutral Wind EstimationAurora López Rubio0Seebany Datta‐Barua1Illinois Institute of Technology Chicago IL USAIllinois Institute of Technology Chicago IL USAAbstract In this work we enable the data assimilation algorithm Estimating Model Parameters from Ionospheric Reverse Engineering (EMPIRE) to estimate global neutral winds. EMPIRE corrects the ion drifts and neutral winds from background models using electron density in the F region derived mainly from total electron content measurements. The new EMPIRE basis functions for the neutral winds are vector spherical harmonics, enforcing the field to be smooth and continuous globally. Global basis functions allow us to estimate the horizontal wind vector from time‐varying plasma densities. The geomagnetic storm on 25 October 2011 is studied to investigate the global implementation of neutral wind estimation. During this storm, the estimates are also compared to those of the old method of estimation using power series and to Fabry‐Perot interferometer (FPI) measurements for validation at three different sites: Pisgah, Cariri, and Nasca. The new global estimation is 10%–20% closer to the FPI measurements than the model and than the old method for most of the viewing directions of the sites, in terms of root‐mean‐square residuals. In the northward direction at Pisgah the estimates using either the old or new implementation disagree with the model, and might be related to an insufficiently small temporal scale used in EMPIRE.https://doi.org/10.1029/2022SW003052 |
| spellingShingle | Aurora López Rubio Seebany Datta‐Barua Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation Space Weather |
| title | Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation |
| title_full | Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation |
| title_fullStr | Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation |
| title_full_unstemmed | Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation |
| title_short | Vector Spherical Harmonics for Data‐Assimilative Neutral Wind Estimation |
| title_sort | vector spherical harmonics for data assimilative neutral wind estimation |
| url | https://doi.org/10.1029/2022SW003052 |
| work_keys_str_mv | AT auroralopezrubio vectorsphericalharmonicsfordataassimilativeneutralwindestimation AT seebanydattabarua vectorsphericalharmonicsfordataassimilativeneutralwindestimation |