A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves
Abstract Waves which couple to energetic electrons are particularly important in space weather, as they drive rapid changes in the topology and intensity of Earth's outer radiation belt during geomagnetic storms. This includes Ultra Low Frequency (ULF) waves that interact with electrons via rad...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2023-07-01
|
| Series: | Space Weather |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2023SW003440 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1841536451957751808 |
|---|---|
| author | Kyle R. Murphy Jasmine Sandhu I. Jonathan Rae Thomas Daggitt Sarah Glauert Richard B. Horne Clare E. J. Watt Sarah Bentley Adam Kellerman Louis Ozeke Alexa J. Halford Sheng Tian Aaron Breneman Leonid Olifer Ian R. Mann Vassilis Angelopoulos John Wygant |
| author_facet | Kyle R. Murphy Jasmine Sandhu I. Jonathan Rae Thomas Daggitt Sarah Glauert Richard B. Horne Clare E. J. Watt Sarah Bentley Adam Kellerman Louis Ozeke Alexa J. Halford Sheng Tian Aaron Breneman Leonid Olifer Ian R. Mann Vassilis Angelopoulos John Wygant |
| author_sort | Kyle R. Murphy |
| collection | DOAJ |
| description | Abstract Waves which couple to energetic electrons are particularly important in space weather, as they drive rapid changes in the topology and intensity of Earth's outer radiation belt during geomagnetic storms. This includes Ultra Low Frequency (ULF) waves that interact with electrons via radial diffusion which can lead to electron dropouts via outward transport and rapid electron acceleration via inward transport. In radiation belt simulations, the strength of this interaction is specified by ULF wave radial diffusion coefficients. In this paper we detail the development of new models of electric and magnetic radial diffusion coefficients derived from in‐situ observations of the azimuthal electric field and compressional magnetic field. The new models use L∗ as it accounts for adiabatic changes due to the dynamic magnetic field coupled with an optimized set of four components of solar wind and geomagnetic activity, Bz, V, Pdyn, and Sym−H, as independent variables (inputs). These independent variables are known drivers of ULF waves and offer the ability to calculate diffusion coefficients at a higher cadence then existing models based on Kp. We investigate the performance of the new models by characterizing the model residuals as a function of each independent variable and by comparing to existing radial diffusion models during a quiet geomagnetic period and through a geomagnetic storm. We find that the models developed here perform well under varying levels of activity and have a larger slope or steeper gradient as a function of L∗ as compared to existing models (higher diffusion at higher L∗ values). |
| format | Article |
| id | doaj-art-f7308bb0ef5a4b849e9a2bcfd7fd7b3f |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2023-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-f7308bb0ef5a4b849e9a2bcfd7fd7b3f2025-01-14T16:27:34ZengWileySpace Weather1542-73902023-07-01217n/an/a10.1029/2023SW003440A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF WavesKyle R. Murphy0Jasmine Sandhu1I. Jonathan Rae2Thomas Daggitt3Sarah Glauert4Richard B. Horne5Clare E. J. Watt6Sarah Bentley7Adam Kellerman8Louis Ozeke9Alexa J. Halford10Sheng Tian11Aaron Breneman12Leonid Olifer13Ian R. Mann14Vassilis Angelopoulos15John Wygant16Self—Independent Researcher Thunder Bay ON CanadaDepartment of Maths, Physics and Electrical Engineering Northumbria University Newcastle Upon Tyne UKDepartment of Maths, Physics and Electrical Engineering Northumbria University Newcastle Upon Tyne UKBritish Antarctic Survey Cambridge UKBritish Antarctic Survey Cambridge UKBritish Antarctic Survey Cambridge UKDepartment of Maths, Physics and Electrical Engineering Northumbria University Newcastle Upon Tyne UKDepartment of Maths, Physics and Electrical Engineering Northumbria University Newcastle Upon Tyne UKDepartment of Earth, Planetary, and Space Sciences University of California Los Angeles Los Angeles CA USADepartment of Physics University of Alberta Edmonton AB CanadaNASA Goddard Spaceflight Center Greenbelt MD USADepartment of Atmospheric and Oceanic Sciences University of California Los Angeles Los Angeles CA USANASA Goddard Spaceflight Center Greenbelt MD USADepartment of Physics University of Alberta Edmonton AB CanadaDepartment of Maths, Physics and Electrical Engineering Northumbria University Newcastle Upon Tyne UKDepartment of Earth, Planetary, and Space Sciences University of California Los Angeles Los Angeles CA USASchool of Physics and Astronomy University of Minnesota Minneapolis MN USAAbstract Waves which couple to energetic electrons are particularly important in space weather, as they drive rapid changes in the topology and intensity of Earth's outer radiation belt during geomagnetic storms. This includes Ultra Low Frequency (ULF) waves that interact with electrons via radial diffusion which can lead to electron dropouts via outward transport and rapid electron acceleration via inward transport. In radiation belt simulations, the strength of this interaction is specified by ULF wave radial diffusion coefficients. In this paper we detail the development of new models of electric and magnetic radial diffusion coefficients derived from in‐situ observations of the azimuthal electric field and compressional magnetic field. The new models use L∗ as it accounts for adiabatic changes due to the dynamic magnetic field coupled with an optimized set of four components of solar wind and geomagnetic activity, Bz, V, Pdyn, and Sym−H, as independent variables (inputs). These independent variables are known drivers of ULF waves and offer the ability to calculate diffusion coefficients at a higher cadence then existing models based on Kp. We investigate the performance of the new models by characterizing the model residuals as a function of each independent variable and by comparing to existing radial diffusion models during a quiet geomagnetic period and through a geomagnetic storm. We find that the models developed here perform well under varying levels of activity and have a larger slope or steeper gradient as a function of L∗ as compared to existing models (higher diffusion at higher L∗ values).https://doi.org/10.1029/2023SW003440ULF wavesradial diffusionradiation electron belt dynamicsL*solar wind drivinggeomagnetic activity |
| spellingShingle | Kyle R. Murphy Jasmine Sandhu I. Jonathan Rae Thomas Daggitt Sarah Glauert Richard B. Horne Clare E. J. Watt Sarah Bentley Adam Kellerman Louis Ozeke Alexa J. Halford Sheng Tian Aaron Breneman Leonid Olifer Ian R. Mann Vassilis Angelopoulos John Wygant A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves Space Weather ULF waves radial diffusion radiation electron belt dynamics L* solar wind driving geomagnetic activity |
| title | A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves |
| title_full | A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves |
| title_fullStr | A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves |
| title_full_unstemmed | A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves |
| title_short | A New Four‐Component L*‐Dependent Model for Radial Diffusion Based on Solar Wind and Magnetospheric Drivers of ULF Waves |
| title_sort | new four component l dependent model for radial diffusion based on solar wind and magnetospheric drivers of ulf waves |
| topic | ULF waves radial diffusion radiation electron belt dynamics L* solar wind driving geomagnetic activity |
| url | https://doi.org/10.1029/2023SW003440 |
| work_keys_str_mv | AT kylermurphy anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT jasminesandhu anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT ijonathanrae anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT thomasdaggitt anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT sarahglauert anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT richardbhorne anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT clareejwatt anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT sarahbentley anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT adamkellerman anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT louisozeke anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT alexajhalford anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT shengtian anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT aaronbreneman anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT leonidolifer anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT ianrmann anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT vassilisangelopoulos anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT johnwygant anewfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT kylermurphy newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT jasminesandhu newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT ijonathanrae newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT thomasdaggitt newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT sarahglauert newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT richardbhorne newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT clareejwatt newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT sarahbentley newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT adamkellerman newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT louisozeke newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT alexajhalford newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT shengtian newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT aaronbreneman newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT leonidolifer newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT ianrmann newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT vassilisangelopoulos newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves AT johnwygant newfourcomponentldependentmodelforradialdiffusionbasedonsolarwindandmagnetosphericdriversofulfwaves |