In our OceanDSL research project, we aim to produce Domain-Specific Languages (DSLs) for scientists and technicians to support and ease their work. We learned that through a set of interviews with them that every model uses special self-made tools and methods to configure, build and run models. This makes our effort complicated. Therefore, we need a model which is fairly simple to setup, but covers all typical steps in model setup. We choose MITgcm based on a recommendation of a collaborating scientist.
MITgcm is an earth model including ocean and atmosphere. Before we can use it as a case study in our model user and model developer scenarios, we need to make us familiar with the model.
As a first step, we aimed to play with the examples of the model. Therefore, we created a setup which can run directly on a Linux machine and one to be run in a docker container. We tested both setup with the tutorial examples of MITgcm. Based on the Barotropic Ocean Gyre we created an image of the result of the model run and a video showing intermediate results of the model in an animation.
The single images where generated using Octave (as a free Matlab replacement) and transformed into a video with Mencoder.
# Adjust the following path addpath ADD-HERE-FULL-PATH-TO-THE-MITGCM-MATLAB-SCRIPTS XC=rdmds('XC'); YC=rdmds('YC'); # Select a proper value. The start value is 0 Eta=rdmds('Eta',0); contourf(XC/1000,YC/1000,Eta,[-.04:.01:.04]); colorbar; colormap((flipud(hot))); set(gca,'XLim',[0 1200]); set(gca,'YLim',[0 1200])
The script for the animation looks like this:
# Adjust the following path addpath ADD-HERE-FULL-PATH-TO-THE-MITGCM-MATLAB-SCRIPTS XC=rdmds('XC'); YC=rdmds('YC'); # The number of frames depend on your setup for m = 0:60 out=["out" num2str(m, "%04d") ".png"]; # The multiplier depends on your setup Eta=rdmds('Eta',1296*m); hf = figure ("visible", "off"); contourf(XC/1000,YC/1000,Eta,[-.04:.01:.04]); colorbar; colormap((flipud(hot))); set(gca,'XLim',[0 1200]); set(gca,'YLim',[0 1200]); print(hf, out, "-dpng "); endfor
Finally, the mencoder call looks like this:
mencoder mf://out????.png -mf fps=2:type=png -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o output.avi
The setup is available at