title: Plot winds vector from netcdf using python
body: <p>I am currently working in internship on atmospheric/climate physics. I have netcdf datas from ERA5 (copernicus) that I already plotted in different maps, graphics etc...
  I need to plot wind vector with cartopy or anything else except basemap, but I can't figure it out.</p>
  <p>This part of my script look like this right now :</p>
  <pre><code>import xarray as xr
  from netCDF4 import Dataset as NetCDFFile 
  import matplotlib.pyplot as plt
  import numpy as np
  
  import cartopy
  import cartopy.feature as cfeat
  import cartopy.crs as ccrs
  
  ncw = xr.open_dataset('D:\Stage_IGE_CNRS\ERA5.nc')
  nc2 = ncw.sel(time = slice('2016-03-06T06:00:00', '2016-03-31T18:00:00'), level = 1000).mean('time')
      
  u = nc2['u']
  v = nc2['v']
  lon = nc2['longitude']
  lat = nc2['latitude']
  </code></pre>
  <p>Thanks for your help.</p>
  <p>Thomas V.</p>