Property Extraction Algorithm: Magnetic Polarity Inversion Line Characteristics

Description

A magnetic polarity inversion line (MPIL) in the photosphere of an active region (AR) separates distinct patches of positive and negative magnetic polarities. There have been several studies showing the relation between flare occurrence and MPIL characteristics (e.g., Schrijver 2007; Mason and Hoeksema 2010; Falconer et al. 2012). In particular, strong-gradient, strong-field MPILs (^sMPILs) have been considered as the most likely place where flux cancellation and/or flux rope emergence can take place in relation to the triggering of flares (e.g., Fang et al. 2012). We developed an algorithm to determine and characterise ^sMPILs in ARs. 

Input data

B_los and B_r images from SDO/HMI Space-weather HMI Active Region Patch (SHARP) cylindrical equal area (CEA) near-realtime (NRT) data

Output parameters 

MPIL_BLOS.MAX_LENGTH: Length of the longest ^sMPIL segment calculated from B_los of a given AR

MPIL_BLOS.TOT_LENGTH: Total length of ^sMPIL segments calculated from B_los of a given AR

MPIL_BLOS.TOT_USFLUX: Total unsigned magnetic flux around ^sMPIL segments calculated from B_los of a given AR

MPIL_BR.MAX_LENGTH: Length of the longest ^sMPIL segment calculated from B_r of a given AR

MPIL_BR.TOT_LENGTH: Total length of ^sMPIL segments calculated from B_r of a given AR

MPIL_BR.TOT_USFLUX: Total unsigned magnetic flux around ^sMPIL segments calculated from B_r of a given AR

Repository

https://dev.flarecast.eu/stash/projects/FE/repos/mpil-idl/browse

References