Plot a global map from finite volume (FV) grid field (Plot_2D application)

# By line: DSJ 10-MAR-2021
# Script aims to:
# - Plot a world map with coastlines, lon/lat lines, and colorbar
# - Change colormap of the plot
# - Add unit to the plot
# - Add title to the plot
# - Manually set maximum and minimum values of the plot

At the start of a Jupyter notebook you need to import all modules that you will use

# Make sure you have downloaded "Plot_2D.py" script from Github
from Plot_2D import Plot_2D
import xarray as xr # To read NetCDF file
import matplotlib.cm as cm # To change colormap used in plots

Read the sample file

# Make sure you have downloaded "sample.nc" file from Github
ds = xr.open_dataset( 'sample.nc' )

Call Plot_2D script to plot surface CO

Plot_2D( ds['CO'][0,-1,:,:]*1e9 ) # multiply by 1e9 to make it to ppbv

<Plot_2D.Plot_2D at 0x28746bb9b88>
../../_images/Plot_2D_example_1_global_map_7_1.png

You can specify colormap. For more information, you can check colormaps from here: https://matplotlib.org/stable/tutorials/colors/colormaps.html

Plot_2D( ds['CO'][0,-1,:,:]*1e9, cmap=cm.hot_r )

<Plot_2D.Plot_2D at 0x2874c3c5588>
../../_images/Plot_2D_example_1_global_map_9_1.png

Let’s add an unit to the plot by using unit keyword

Plot_2D( ds['CO'][0,-1,:,:]*1e9, cmap=cm.hot_r, unit='ppbv' )

<Plot_2D.Plot_2D at 0x2874c655a08>
../../_images/Plot_2D_example_1_global_map_11_1.png

You can also add a title to the plot

Plot_2D( ds['CO'][0,-1,:,:]*1e9, cmap=cm.hot_r, unit='ppbv', title='CO mixing ratio (SFC)' )

<Plot_2D.Plot_2D at 0x2874c71ac48>
../../_images/Plot_2D_example_1_global_map_13_1.png

Set maximum and minimum values manually with cmin and cmax keywords

Plot_2D( ds['CO'][0,-1,:,:]*1e9, cmap=cm.hot_r, unit='ppbv', title='CO mixing ratio (SFC)',
         cmax=1000, cmin=100 )

<Plot_2D.Plot_2D at 0x2874c980788>
../../_images/Plot_2D_example_1_global_map_15_1.png