<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><span><div><span>Dear colleages</span></div><div><span>How can I calculate the perimeter of specific contour e.g. 5460 gpm contour in 500 hpa level in km for polar vortex in Grads software?</span></div><div><span>Sincerely Yours</span></div><div><span>kashki<var id="yui-ie-cursor"></var></span></span></div><div></div><div> </div><div>Abdolreza Kashki <br>Ph.D. Student of Climatology<br>Department of Physical Geography<br>Faculty of Planing & Geography Science <br>University of Isfahan <br>Isfahan, Iran<br>Postcode:81746-73441<br>Tel:+98(311)7933119<br>Fax:+98(311)7932257<br>Cell:+989151731453</div></div></body></html>