# Read zonal and meridional wind components from file using the iris module. # The components are in separate files. We catch warnings here because the # files are not completely CF compliant. with warnings.catch_warnings(): warnings.simplefilter('ignore', UserWarning) uwnd = iris.load_cube(example_data_path('uwnd_mean.nc')) vwnd = iris.load_cube(example_data_path('vwnd_mean.nc')) uwnd.coord('longitude').circular = True vwnd.coord('longitude').circular = True # Create a VectorWind instance to handle the computation of streamfunction and # velocity potential. w = VectorWind(uwnd, vwnd) # Compute the streamfunction and velocity potential. sf, vp = w.sfvp() # Pick out the field for December. time_constraint = iris.Constraint(month='Dec') add_month(sf, 'time', name='month') add_month(vp, 'time', name='month') sf_dec = sf.extract(time_constraint) vp_dec = vp.extract(time_constraint) # Plot streamfunction. clevs = [-120, -100, -80, -60, -40, -20, 0, 20, 40, 60, 80, 100, 120] ax = plt.subplot(111, projection=ccrs.PlateCarree(central_longitude=180)) fill_sf = iplt.contourf(sf_dec * 1e-06, clevs, cmap=plt.cm.RdBu_r, extend='both') ax.coastlines() ax.gridlines()
# Read zonal and meridional wind components from file using the iris module. # The components are in separate files. We catch warnings here because the # files are not completely CF compliant. with warnings.catch_warnings(): warnings.simplefilter('ignore', UserWarning) uwnd = iris.load_cube(example_data_path('uwnd_mean.nc')) vwnd = iris.load_cube(example_data_path('vwnd_mean.nc')) uwnd.coord('longitude').circular = True vwnd.coord('longitude').circular = True # Create a VectorWind instance to handle the computation of streamfunction and # velocity potential. w = VectorWind(uwnd, vwnd) # Compute the streamfunction and velocity potential. sf, vp = w.sfvp() # Pick out the field for December. time_constraint = iris.Constraint(month='Dec') add_month(sf, 'time', name='month') add_month(vp, 'time', name='month') sf_dec = sf.extract(time_constraint) vp_dec = vp.extract(time_constraint) # Plot streamfunction. clevs = [-120, -100, -80, -60, -40, -20, 0, 20, 40, 60, 80, 100, 120] ax = plt.subplot(111, projection=ccrs.PlateCarree(central_longitude=180)) fill_sf = iplt.contourf(sf_dec * 1e-06, clevs, cmap=plt.cm.RdBu_r, extend='both')