ce tracks toolbox and clip to the eastern hemisphere: 

% Load reference track: 
[lat,lon] = reftrack(1304); 

% Clip to eastern hemisphere: 
lat = lat(lon>0); 
lon = lon(lon>0); 

% Plot for context: 
figure('position',[100 100 800 400])
subplot(1,2,1) 
bedmap2('gl','color','black','xy')
plotps(lat,lon,'b-') 

%%
% Calculate the total distance in meters and plot: 

d = pathdistps(lat,lon); 

subplot(1,2,2)
plot(d,lon) 
xlabel 'distance relative to the grounding line (m)'
ylabel 'longitude (deg)' 

%% 
% Al