Open Access
Table 1.
Keywords, definitions and units of our calculated active region parameters.
| Keyword | Description | Unit | Formula |
|---|---|---|---|
| TOTUSJH | Total unsigned current helicity | G2 m−1 | Hctotal ∝ ∑|Bz.Jz| |
| TOTPOT | Total photospheric magnetic free-energy density | ergs cm−1 | ρtot ∝ ∑(Bobs − Bpot)2dA |
| TOTUSJZ | Total unsigned vertical current | Amperes | Jz, total ∝ ∑|Jz|dA |
| SVANCPP | Sum of the modulus of the net current per polarity | Amperes |
 |
| ABSNZH | Absolute value of the net current helicity | G2 m−1 | Hcabs ∝ |∑Bz.Jz| |
| USFLUX | Total unsigned flux | Maxwell | Φ ∝ ∑|Bz|dA |
| MEANPOT | Mean photospheric magnetic free-energy density | ergs cm−3 |
 |
| MEANGAM | Mean angle of the field from radial | Degrees |
 |
| MEANSHR | Mean shear angle | Degrees |
 |
| SHRGT45 | Fraction of area with shear > 45° | m2 | Area with shear > 45°/total area |
| AREA_ACR | Area of strong-field pixels in an active region | m2 | Area = ∑Pixels |
| MEANGBT | Mean gradient of the total field | G Mm−1 |
 |
| MEANGBZ | Mean gradient of the vertical field | G Mm−1 |
 |
| MEANGBH | Mean gradient of the horizontal field | G Mm−1 |
 |
| MEANJZH | Mean current helicity | G2 m−1 |
 |
| MEANJZD | Mean vertical current density | mA m−2 |
 |
| MEANALP | Mean characteristic twist parameter, α | 1 Mm |
 |
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