Table 3.
The solar features identification criteria that have been adopted in this work, and the parameters employed to identify them, from the respective data set. Intensitygrams and magnetograms are shortened to Int and Mag, respectively.
| Feature | Data type | Detection criterium | Description |
|---|---|---|---|
| Sunspots | Int | Th ss = 〈I〉 − f ss | where f ss = 15 |
| Pores | Int | Th pores = 〈I〉region − (f p × σ I,SMin) | where f p = 7, and σ I,SMin = 1.5 |
| Umbra, penumbra | Int | Th up = 〈I〉ss − σ ss | where 〈I〉ss is the mean of sunspot groups and σ ss is the standard deviation of sunspot group. Umbra and penumbra are defined after the detection of sunspots. Sunspot pixels with values below the threshold are classified as umbra, while the remaining sunspot pixels are classified as penumbra. |
| Faculae | Mag | Th mr = 〈B〉 ± (f mr × σ B,SMin) | where f mr = 2 and σ B,SMin = 2.4 |
| Faculae are magnetic regions, except sunspots, located within active region boundaries | |||
| Network | Mag | Th mr = 〈B〉 ± (f mr × σ B,SMin) | where f mr = 2 and σ B,SMin = 2.4 |
| Network are magnetic regions located outside active regions. |
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