----------------- March 2020 -----------------------------
------ Paula Koelemeijer - Royal Holloway ----------------

Files contain average models and vote maps describing the seismological landscape of the core-mantle boundary (Koelemeijer, AGU books, 2020). 

- Average models are computed similar to SMEAN (Becker & Boschi, 2002) or PMEAN, except that only depth slices at 2800 km depth are considered. 
- Vote maps are computed for a positive or negative mean following Shephard et al. (2017), again for structure at 2800 km depth. 
- Combined vote maps based on a combination of the positive and negative mean are provided in addition. 

Note that while these average models and vote maps aid in finding model consistencies, they do not necessarily fit seismological data and are not intended as replacement of the original models. 

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Average models and vote maps are computed for existing density models from the literature as indicated below:

### Density (rho), for models expanded up to degree 2 or 6:

IT1999		Ishii and Tromp, 1999
Tetal2004 	Trampert et al., 2004 (mean model)
Metal2012	Mosca et al., 2012 (mean model)
ME2016 		Moulik and Ekstrom, 2016
Letal2017	Lau et al., 2017 (mean model)

and either of the following:

KDR2017-pos 	Koelemeijer et al., 2017 (best-fitting model for positive model class)
KDR2017-neg 	Koelemeijer et al., 2017 (best-fitting model for negative model class)

This results in two selections for density: rho_neg-class and rho_pos-class. 

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For each selection of models (selection) and each spherical harmonic degree expansion (lmax), 
the following files are provided: 

average_model_${selection}_lc${lmax}.xyz  		
votemap_negative-mean_${selection}_lc${lmax}.xyz  
votemap_positive-mean_${selection}_lc${lmax}.xyz  
votemap_combined-mean_${selection}_lc${lmax}.xyz  

e.g. for density models including the positive density class for degree 2:
average_model_rho_pos-class_lc2.xyz
votemap_negative-mean_rho_pos-class_lc2.xyz
votemap_positive-mean_rho_pos-class_lc2.xyz
votemap_combined-mean_rho_pos-class_lc2.xyz

In each case, the file contains three columns (points at every 5x5 degrees): 
Latitude (ge-90,90), Longitude (-180,180), Value
where for vote maps the value is the number of votes  
and for average models this is in percent deviations from PREM. 

For each selection of models (selection) and each spherical harmonic degree expansion (lmax), 
a figure plotting the relevant files is also provided: 
globe_aver-vote-combi_${selection}_lc${lmax}.pdf  

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Overview plots are also provided, for the different degrees: 
globe_aver-vote-combi_density_lc${lmax}.pdf
where lmax is 2 or 6.

These plots are consistent with the figures in the publication (Koelemeijer, 2020). 

