1% A realistic example of divand in 2 dimensions 2% with salinity observations in the Mediterranean Sea at 30m. 3% 4% Data is available at 5% http://modb.oce.ulg.ac.be/mediawiki/index.php/Divand 6 7% load observations 8 9load data.dat 10 11% extract columns of data 12lonobs = data(:,1); 13latobs = data(:,2); 14S = data(:,3); 15 16% load bathymetry 17% bath is negative in water and positive in air 18bat = ncread('diva_bath.nc','bat'); 19lon = ncread('diva_bath.nc','lon'); 20lat = ncread('diva_bath.nc','lat'); 21 22% compute grid metric 23% pm and pn are in meters^-1 24[lon,lat] = ndgrid(lon,lat); 25[pm,pn] = divand_metric(lon,lat); 26 27% compute mean and anomalies 28Smean = mean(S); 29Sanom = S - mean(S); 30 31% correlation length (in meters) 32len = 200e3; 33len = 100e3; 34% signal-to-noise ratio 35lambda = 50.5; 36 37% land-sea mask 38% mask everything below 30 m 39mask = bat < -30; 40 41% mask for the analysis 42maska = mask; 43% remove Atlantic 44maska(1:60,130:end) = 0; 45% remove Black Sea 46maska(323:end,100:end) = 0; 47 48% make analysis 49Sa = divand(maska,{pm,pn},{lon,lat},{lonobs,latobs},Sanom,len,lambda); 50 51% add mean back 52Sa2 = Sa + Smean; 53 54% create plots 55 56% color axis 57ca = [36.2520 39.4480]; 58 59% aspect ratio 60ar = [1 cos(mean(lat(:)) * pi/180) 1]; 61 62 63subplot(2,1,1); 64scatter(lonobs,latobs,10,S) 65caxis(ca); 66colorbar 67hold on, contour(lon,lat,mask,0.5,'k') 68xlim(lon([1 end])) 69ylim(lat([1 end])) 70title('Observations'); 71set(gca,'DataAspectRatio',ar,'Layer','top') 72 73subplot(2,1,2); 74pcolor(lon,lat,Sa2), shading flat,colorbar 75hold on 76plot(lonobs,latobs,'k.','MarkerSize',1) 77caxis(ca) 78contour(lon,lat,mask,0.5,'k') 79xlim(lon([1 end])) 80ylim(lat([1 end])) 81title('Analysis'); 82set(gca,'DataAspectRatio',ar,'Layer','top') 83 84set(gcf,'PaperUnits','centimeters','PaperPosition',[0 0 15 15 ]); 85print -dpng divand_realistic_example.png 86% Copyright (C) 2014 Alexander Barth <a.barth@ulg.ac.be> 87% 88% This program is free software; you can redistribute it and/or modify it under 89% the terms of the GNU General Public License as published by the Free Software 90% Foundation; either version 2 of the License, or (at your option) any later 91% version. 92% 93% This program is distributed in the hope that it will be useful, but WITHOUT 94% ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 95% FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 96% details. 97% 98% You should have received a copy of the GNU General Public License along with 99% this program; if not, see <http://www.gnu.org/licenses/>. 100