Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter
Plasma velocity distribution functions (VDFs) constitute a fundamental observation of numerous operational and future missions. An efficient parameterization of VDFs is crucial for (1) preserving enough information to investigate macroscopic moments along with kinetic effects, (2) producing smooth d...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adb6a0 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849344413909647360 |
|---|---|
| author | Srijan Bharati Das Michael Terres |
| author_facet | Srijan Bharati Das Michael Terres |
| author_sort | Srijan Bharati Das |
| collection | DOAJ |
| description | Plasma velocity distribution functions (VDFs) constitute a fundamental observation of numerous operational and future missions. An efficient parameterization of VDFs is crucial for (1) preserving enough information to investigate macroscopic moments along with kinetic effects, (2) producing smooth distributions whereby it is possible to perform derivatives in phase space to support numerical solvers, and (3) economic data management and its storage. Previous studies have used spherical harmonics as an efficient basis for representing electron VDFs. In this paper, we present a novel algorithm targeted toward decomposing ion VDFs measured by electrostatic analyzers on board Magnetospheric Multiscale (MMS) Mission and Solar Orbiter (SolO) spacecraft. We use Slepian functions, custom-designed bases providing compact support in phase space, initially developed in information theory and later used for terrestrial and planetary applications. In this paper, we choose well-studied, well-measured, and complex intervals from MMS and SolO containing a range of simpler gyrotropic and agyrotropic distributions to benchmark the robustness of our reconstruction method. We demonstrate the advantages of using Slepian functions over spherical harmonics for solar wind plasma distributions. We also demonstrate that our choice of basis representation efficiently preserves phase space complexities of a 3D agyrotropic distribution function. This algorithm shown in this study will be extended to Parker Solar Probe and future missions such as Helioswarm. |
| format | Article |
| id | doaj-art-607b3f2266664f33a54f26be640e8910 |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-607b3f2266664f33a54f26be640e89102025-08-20T03:42:40ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198229610.3847/1538-4357/adb6a0Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar OrbiterSrijan Bharati Das0https://orcid.org/0000-0003-0896-7972Michael Terres1https://orcid.org/0000-0003-4747-6252Center for Astrophysics—Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; srijanbdas@alumni.princeton.eduCenter for Astrophysics—Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; srijanbdas@alumni.princeton.eduPlasma velocity distribution functions (VDFs) constitute a fundamental observation of numerous operational and future missions. An efficient parameterization of VDFs is crucial for (1) preserving enough information to investigate macroscopic moments along with kinetic effects, (2) producing smooth distributions whereby it is possible to perform derivatives in phase space to support numerical solvers, and (3) economic data management and its storage. Previous studies have used spherical harmonics as an efficient basis for representing electron VDFs. In this paper, we present a novel algorithm targeted toward decomposing ion VDFs measured by electrostatic analyzers on board Magnetospheric Multiscale (MMS) Mission and Solar Orbiter (SolO) spacecraft. We use Slepian functions, custom-designed bases providing compact support in phase space, initially developed in information theory and later used for terrestrial and planetary applications. In this paper, we choose well-studied, well-measured, and complex intervals from MMS and SolO containing a range of simpler gyrotropic and agyrotropic distributions to benchmark the robustness of our reconstruction method. We demonstrate the advantages of using Slepian functions over spherical harmonics for solar wind plasma distributions. We also demonstrate that our choice of basis representation efficiently preserves phase space complexities of a 3D agyrotropic distribution function. This algorithm shown in this study will be extended to Parker Solar Probe and future missions such as Helioswarm.https://doi.org/10.3847/1538-4357/adb6a0Space plasmasSolar windRegressionSolar instruments |
| spellingShingle | Srijan Bharati Das Michael Terres Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter The Astrophysical Journal Space plasmas Solar wind Regression Solar instruments |
| title | Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter |
| title_full | Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter |
| title_fullStr | Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter |
| title_full_unstemmed | Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter |
| title_short | Recovering Ion Distribution Functions. I. Slepian Reconstruction of Velocity Distribution Functions from MMS and Solar Orbiter |
| title_sort | recovering ion distribution functions i slepian reconstruction of velocity distribution functions from mms and solar orbiter |
| topic | Space plasmas Solar wind Regression Solar instruments |
| url | https://doi.org/10.3847/1538-4357/adb6a0 |
| work_keys_str_mv | AT srijanbharatidas recoveringiondistributionfunctionsislepianreconstructionofvelocitydistributionfunctionsfrommmsandsolarorbiter AT michaelterres recoveringiondistributionfunctionsislepianreconstructionofvelocitydistributionfunctionsfrommmsandsolarorbiter |