Example NorthPolarStereo_projection

# Example: Plot on NorthPolarStereo and set the latitude limit

import xarray as xr
import numpy as np
import matplotlib.pyplot as plt
# or
# from imports import (plt, np, xr)
path = '~/shared-cmip6-for-ns1000k/historical/NorESM2-LM/r1i1p1f1/abs550aer_AERmon_NorESM2-LM_historical_r1i1p1f1_gn_185001-185912.nc'
ds = xr.open_dataset(path)

import cartopy.crs as ccrs
import cartopy as cy
def sp_map(*nrs, projection = ccrs.PlateCarree(), **kwargs):
return plt.subplots(*nrs, subplot_kw={'projection':projection}, **kwargs)

ax.coastlines()
gl = ax.gridlines()
gl = ax.gridlines()#draw_labels=True)
gl.xlabels_top = False
gl.ylabels_right = False

import matplotlib.path as mpath

def polarCentral_set_latlim(lat_lims, ax):
ax.set_extent([-180, 180, lat_lims[0], lat_lims[1]], ccrs.PlateCarree())
# Compute a circle in axes coordinates, which we can use as a boundary
# for the map. We can pan/zoom as much as we like - the boundary will be
# permanently circular.
theta = np.linspace(0, 2*np.pi, 100)
center, radius = [0.5, 0.5], 0.5
verts = np.vstack([np.sin(theta), np.cos(theta)]).T
circle = mpath.Path(verts * radius + center)

ax.set_boundary(circle, transform=ax.transAxes)


### Now plot!

Example with latitude from 70-90:

# Make the axis with NorthPolarStereo() projection:
fig, ax = sp_map(1, projection=ccrs.NorthPolarStereo() )
lat_lims = [70,90]
ds['abs550aer'].isel(time=0).where(ds['lat']>lat_lims[0]).plot(ax=ax, cmap=plt.get_cmap('Reds'),transform=ccrs.PlateCarree())
polarCentral_set_latlim(lat_lims, ax)
plt.show()


### Make seasonal means:

ds_seas = ds.groupby('time.season').mean()
fig, axs = sp_map(2,2, projection=ccrs.NorthPolarStereo(), figsize=[10,10] )
lat_lims = [70,90]
season_l = ds_seas['season'].values
print(season_l)
for ax, seas in zip(axs.flatten(),season_l):
ds_seas.sel(season=seas)['abs550aer'].where(ds_seas['lat']>lat_lims[0]).plot(ax=ax, cmap=plt.get_cmap('Reds'),transform=ccrs.PlateCarree())
ax.set_title(seas)
polarCentral_set_latlim(lat_lims, ax)

['DJF' 'JJA' 'MAM' 'SON']