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Barotropic-Python

A simple barotropic model written in Python using the spharm package for spherical harmonics.

Currently set up to use NCEP reanalysis for initial conditions

Written by Luke Madaus (5/2012) - University of Washington

Requires: PySPHARM -- Python interface to NCAR SPHEREPACK library: https://code.google.com/p/pyspharm/

netCDF4 -- Python interface to netCDF4 library matplotlib numpy

Based on the Held-Suarez Barotropic model, including hyperdiffusion. A brief description of their model may be found at: http://data1.gfdl.noaa.gov/~arl/pubrel/m/atm_dycores/src/atmos_spectral_barotropic/barotropic.pdf

The basic premise of the code is to take 500 hPa u and v winds from the NCEP reanalysis, extract the non-divergent component, compute vorticity, and advect along this vorticity using the barotropic vorticity equation. As this model uses "real" atmospheric data (which is not barotropic), the results are rarely stable beyond ~5 days of forecasting.