----------------- 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. 

##########################################################

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

### CMB topography (topo), for models expanded up to degree 2 or 6:

- Models based on body waves (body):

MD1987 		Morelli and Dziewonski, 1987
DH1989-M6 	Doornbos and Hilton, 1989
SV2003		Sze and van der Hilst, 2003
T2010 		Tanaka, 2010
SBF2012-T	Soldati et al., 2012
SBF2012-TGppv 	Soldati et al., 2012

- Models based on normal-modes (modes):
LGW1991-SAF	Li et al., 1991
LGW1991-SAT 	Li et al., 1991
IT1999 		Ishii and Tromp, 1999
KDR2017 	Koelemeijer et al., 2017

Three selections are therefore present for CMB topography: topo_body, topo_modes and topo_all. 

##########################################################

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 all CMB topography models for degree 2:
average_model_topo_all_lc2.xyz
votemap_negative-mean_topo_all_lc2.xyz
votemap_positive-mean_topo_all_lc2.xyz
votemap_combined-mean_topo_all_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 kilometers as 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  

##########################################################

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

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

