List of External Features (Wu & Liu, 2021)
| Observation Category | Feature | Description |
|---|---|---|
| Space-based | Bx (GSE) | Solar wind interplanetary magnetic field (IMF) x component in geocentric solar ecliptic (GSE) system (J. H. King & Papitashvili, 2005) |
| By (GSE) | Solar wind IMF y component in GSE system (J. H. King & Papitashvili, 2005) | |
| Bz (GSE) | Solar wind IMF z component in GSE system (J. H. King & Papitashvili, 2005) | |
| By (GSM) | Solar wind IMF y component in geocentric solar magnetospheric (GSM) system (J. H. King & Papitashvili, 2005) | |
| Bz (GSM) | Solar wind IMF z component in GSM system (J. H. King & Papitashvili, 2005) | |
| Magnetic field magnitude | Magnitude of solar wind IMF (J. H. King & Papitashvili, 2005) | |
| Vx velocity (GSE) | Solar wind flow velocity x component in GSE system (J. H. King & Papitashvili, 2005) | |
| Vy velocity (GSE) | Solar wind flow velocity y component in GSE system (J. H. King & Papitashvili, 2005) | |
| Vz velocity (GSE) | Solar wind flow velocity z component in GSE system (J. H. King & Papitashvili, 2005) | |
| Flow speed | Solar wind flow speed (J. H. King & Papitashvili, 2005) | |
| Proton density | Plasma proton density (J. H. King & Papitashvili, 2005) | |
| Temperature | Plasma temperature (J. H. King & Papitashvili, 2005) | |
| Flow pressure | Solar wind flow pressure (J. H. King & Papitashvili, 2005) | |
| Electric field | Electric field (Papitashvili, n.d.) | |
| Plasma beta | Beta value of a plasma (Burke, n.d.; J. H. King & Papitashvili, 2005) | |
| Alfven speed | Speed of Alfven wave (J. H. King & Papitashvili, 2005) | |
| Lyman alpha | Solar irradiance measurements of the bright H I 121.5-nm emission (Machol et al., 2019) | |
| Ground-based | AE index | Aurora-electrojet index (Mandea & Korte, 2010) |
| AL index | AL index (Mandea & Korte, 2010) | |
| AU index | AU index (Mandea & Korte, 2010) | |
| SYM index | Symmetric index (Mandea & Korte, 2010) | |
| ASY index | Asymmetric index (Mandea & Korte, 2010) | |
| PC(N) index | Polar cap index (Mandea & Korte, 2010) | |
| CCP | Cross cap potential (Greenwald et al., 1995) | |
| Kp index | Kp index (Mandea & Korte, 2010) | |
| Sunspot number | Sunspot number (Mandea & Korte, 2010) | |
| Dst index | Disturbance storm time index (Mandea & Korte, 2010) | |
| Ap index | Ap index (Mandea & Korte, 2010) | |
| F10.7 | 10.7-cm-wavelength solar flux (McGranaghan et al., 2018; Tapping, 2013) |