title: Plot a contour map of v component of geostrophic velocity
body: <p>I need your help to figure out the answer for this question. I've spent my 3 days but I haven't still figured out how to do this.
  Here my question: 
  <a href="https://i.stack.imgur.com/OiOuT.png" rel="nofollow noreferrer">https://i.stack.imgur.com/OiOuT.png</a></p>