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Description

...

Name: 

mpil.pro

Purpose: 

Calculate some characteristics of 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

field magnetic polarity inversion lines (MPILs) in active regions

Calling sequence:

output_mpil = mpil(c_img [,mpil_info=mpil_info] [,mpil_xy=mpil_xy] [,binxy=binxy] [,detail1=detail1] [,minsize1=minsize1] [,pbt_thresh1=pbt_thresh1] [,thresh1=thresh1] [,isth_cut1=isth_cut1], $

                              [detail2=detail2] [,minsize2=minsize2] [,pbt_thresh2=pbt_thresh2] [,thresh2=thresh2] [,isth_cut2=isth_cut2] [,sep=sep] [,xy_pixel=xy_pixel])

Input parameters:

c_img - 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

Optional Input Keyword Parameters:

binxy - number for xy spatial binning of the sharp magnetic field input data [in pixels] ; default=1 (i.e., no binning)

detail1 & detail2 - width of the smoothing window, which is used for a two-step MPIL detection algorithm [in pixels] ; default=6 & 3

minsize1 & minsize2 - threshold for the length of a single MPIL (used for two-step MPIL detection algorithm) [in Mm] ; default=5.5 & 2

pbt_thresh1 & pbt_thresh2 - threshold for the strength of the horizontal component of potential magnetic field on the photosphere (used for two-step MPIL detection algorithm) [in Gauss]; defualt=120 & 100

thresh1 & thresh2 - threshold for the gradient of Bz on the photosphere (used for two-step MPIL detection algorithm) [Gauss] ; defualt=20 & 8

isth_cut1 & isth_cut2 - distance within which separated segments of a single MPIL will be connected (used for two-step MPIL detection algorithm) [in Mm]; default=2 & 1

grad_width - distance for the horizontal gradient of Bz [in Mm]; default=3.5

sep - distance within which MPILs will be considered as a same group [in Mm]; default=11

xy_pixel - xy distance from MPILs for calculating total unsigned magnetic flux around MPILs [in Mm]; default=2

Optional Output Keyword Parameters:  

mpil_info - information on types of MPILs

mpil_xy - x and y coordinates of MPILs [pixels]

Output parameters:

output_mpil - 3 element 1D array related to the properties of MPILs

                      output_mpil[0]: total length of MPILs [Mm]

                      output_mpil[1]: length of the longest MPIL [Mm] 

                      output_mpil[2]: total unsigned magnetic flux around MPILs [10^20 Mx]

Property name in DB:

mpil_blos.max_length, mpil_blos.tot_length, mpil_blos.tot_usflux, mpil_br.max_length, mpil_br.tot_length, mpil_br.tot_usflux

Repository

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

References