2D Weather

2D Weather (Two Dimensional Weather) was conceived as a desk-top laboratory in which I and my students could explore the dynamics of a very simple weather system.  This is an unfinished application.  The effects of moisture, humidity and therefore also precipitation are not implemented yet.  Nevertheless, students were impressed when sunshine caused circulation of air and hydraulic patterns of air flow over terrain.

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This laboratory, built for high school students, is intended to provide "weather in a box".  A vastly simplified weather model, all "cells" in the model are two-dimensional squares, and surface curvature of the Earth is neglected.  Students can alter simple landforms and watch solar-driven convection currents develop in minutes.  The current unfinished version is dry.  I.e. the air is dry, and no clouds or precipitation plays any role.  My original vision was to see clouds form, but I currently have no plans to finish this bit of software.  The software does not attempt to emulate or simulate physical reality.  Rather, it creates a logical reality consisting of a box of variable construction in which the weather develops.  However, all changes in the system are controlled by the laws of physics and chemistry, applied iteratively over time.  Conservation of energy, mass and momentum play a role, as do the gas laws such as PV=nRT.  Air masses have a velocity which moves them towards other cells, causing changes in density and pressure, changes in energy concentrations and temperatures, changes in forces and accelerations, and new velocities.  Students can visualize how the temperature, pressure, density and wind speed vary from cell to cell as the sun pours energy in, and an atmospheric sink draws energy out.  To download it, click here Weather.zip (0.952 Mb).   The help files associated with 'Weather' are vacant stubs.

Figure 1 - In this basic 2D Weather box, heat from the sun warms the water (bottom right), which warms the air above it, causing a small pressure change, and expansion (light blue).  An energy sink (grey, top left) cools the air, causing a pressure change, and contraction (darker blue).  Arrows show air flow.  Shading shows pressure differences.  My students and I worked out the sets of seven recursive equations per cell.  They were delighted to see the convection currents develop.  Other configurations demonstrate hydraulic effects, if you look for them. 

Last updated: September 2014.