Table 1

The complete list of FLARECAST properties, separated in property groups and accounting for a total of 209 predictors. The vast majority (197) of them correspond to the AR magnetic field, while the rest include information from the NOAA SWPC Catalogues and from photospheric intensity images.

Data Source Property group No. of predictors Relevant predictor Adapted from Related references
SWPC Solar region summary (SRS) properties 2 McIntosh and Hale classes McCloskey et al. (2016) McIntosh (1990)
3 Number, area and longitudinal extend of sunspots Lee et al. (2012)
Catalogues GOES soft X-ray flare eventsa, b 4 Flare magnitude, start, peak, and end times
Surface-normal component (radial and line-of-sight) magnetograms Effective connected magnetic field strengthc 1 B eff Georgoulis & Rust (2007), Georgoulis (2011, 2013)
Fractal and multifractal parameters 1 Fractal dimension Conlon et al. (2008) Abramenko et al. (2003)
1 Generalized correlation dimension Abramenko (2005)
2 Holder exponent; Hausdorff dimension Al-Ghraibah et al. (2015)
2 Structure function’s inertial range index
Fourier and Wavelet power spectral indices 2 Power-law exponent Hewett et al. (2008), Guerra et al. (2015)
Decay index (DI)d 8 Mean DI over PIL segments; height of DI; ratio of PIL length to DI height Liu (2008)
Zuccarello et al. (2014)
Magnetic PIL properties 5 Sum of PIL segments, longest PIL segment Mason & Hoeksema (2010)
1 R value Schrijver (2007)
1 WLsg Falconer et al. (2012)
3D magnetic null pointsd 6 Number of null points in different height ranges Haynes & Parnell (2007) Pontin et al. (2013)
(from 2 to 100 Mm above photosphere) Barnes & Leka (2006)
Ising Energyc 6 Original and partitioned Ising energy Ahmed et al. (2010) Kontogiannis et al. (2018)
Magnetic energy and helicity 11 Poynting flux and magnetic helicity flux proxies Park et al. (2010)
Park et al. (2012)
Full-vector magnetograms SHARP propertiese 100 Horizontal gradient of B components; shear angle; unsigned vertical current; higher-order moments of time series Bobra et al. (2014)
Leka & Barnes (2003b, 2007)
Magnetic energy and helicity 22 Poynting flux and magnetic helicity flux Kusano et al. (2002) Berger & Field (1984), Welsch et al. (2009)
Non-neutralized currents 6 Total non-neutralized current Georgoulis et al. (2012) Kontogiannis et al. (2017)
Flows around PIL 22 Speed of diverging/converging/shear flows Park et al. (2018) Deng et al. (2006), Wang et al. (2014)
Intensity imagesf Magnetic field gradient 3 Total horizontal magnetic gradient Korsós et al. (2014) Kontogiannis et al. (2018)

AR coronal information.


The project uses the flare attributes as properties. At least one flare of desired magnitude in the forecast window signifies a positive instance.


Photospheric proxy for coronal information.


Uses PFEs.


Most SHARP parameters correspond to mean values. In the FLARECAST pipeline, other relevant magnetogram-related parameters are also used as predictors; these are maximum and minimum values, median, standard deviation, kurtosis, and skewness.


Used in conjunction with magnetograms to calculate the sum of the magnetic field gradients between all possible opposite-polarity umbrae pairs.

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