Open Access
Table 1.
SHARPs physics-based feature set.
| Acronym | Description | Units |
|---|---|---|
| LAT_FWT | Latitude of the flux-weighted center of active pixels | degrees |
| LON_FWT | Longitude of the flux-weighted center of active pixels | degrees |
| AREA_ACR | Line-of-sight field active pixel area | microhemispheres |
| USFLUX | Total unsigned flux | Mx |
| MEANGAM | Mean inclination angle, γ | degrees |
| MEANGBT | Mean value of the total field gradient | G Mm−1 |
| MEANGBZ | Mean value of the vertical field gradient | G Mm−1 |
| MEANGBH | Mean value of the horizontal field gradient | G Mm−1 |
| MEANJZD | Mean vertical current density | mA m−2 |
| TOTUSJZ | Total unsigned vertical current | A |
| MEANALP | Total twist parameter, α | Mm−1 |
| MEANJZH | Mean current helicity | G2 m−1 |
| TOTUSJH | Total unsigned current helicity | G2 m−1 |
| ABSNJZH | Absolute value of the net current helicity | G2 m−1 |
| SAVNCPP | Sum of the absolute value of the net currents per polarity | A |
| MEANPOT | Mean photospheric excess magnetic energy density | ergs cm−3 |
| TOTPOT | Total photospheric magnetic energy density | ergs cm−3 |
| MEANSHR | Mean shear angle (measured using Btotal) | degrees |
| SHRGT45 | Percentage of pixels with a mean shear angle greater than 45 deg. | percent |
| R_VALUE | Sum of flux near polarity inversion line | Mx |
Notes. Values for these 20 features, together with error estimates, are available for each magnetogram in the SDO SHARPs database. Abbreviations: A and mA are Amperes and milli-Amperes, respectively; Mm is megameters, G is Gauss and Mx is Maxwells.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.