title: Sphere cartopy gridspacing and Labeling
body: <p>I'm projecting a 2D map onto a sphere with cartopy and the gridlines keep doing what they want. Especially my xz perspective is messy!</p>
  
  <p>I would love to place them like every 30° in both directions. </p>
  
  <p>My code right now is like this</p>
  
  <pre><code>plt.figure(figsize=(10, 10))
  
  ax = plt.axes(projection=ccrs.Orthographic(0, -90))
  ax.gridlines(color='black', linestyle='dotted',linewidth='2')
  ax.imshow(img, origin="upper", extent=(-180, 180, -90, 90),
            transform=ccrs.PlateCarree())  # Important
  </code></pre>
  
  <p>The image
  <a href="https://i.stack.imgur.com/KXQue.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KXQue.png" alt="enter image description here"></a></p>
  
  <p>Also I would love to label certain meridians like 270°</p>