<div dir="ltr"><div><div>Hi Rym,<br><br></div>I don't definitively know a solution, but I wonder if you might be able to get what you need by either i) rotating/translating your data somewhere off pole to do the in/out calculation, then rotating back, or ii) performing the calculation in a map projection, and again, deprojecting the results back ?<br><br></div>Rick<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Dec 1, 2016 at 7:10 AM, Rym Msadek <span dir="ltr"><<a href="mailto:msadek@cerfacs.fr" target="_blank">msadek@cerfacs.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">Hi,<div><br></div><div>I am trying to use the gc_inout function to define a polygon over the Arctic region and use that as a mask to average an oceanic field like potential temperature.</div><div>I have an issue when the longitudes and latitudes of the polygon cover a region that crosses the North pole. gcinout gives me a contour that is not closed and I can’t figure out how to overcome this issue.<br><div><br></div><div>Here are the lon lat that define my polygon, over the Eurasian basin of the Arctic.</div><div>---------</div><div><div>latC=(/81,81.5,82,82.7,82.4,<wbr>81.6,80,78.8,77,78,79,81,82,<wbr>84,88,88.5,89,86,85,85,84,83,<wbr>82,82,81/)</div><div>lonC=(/27,36,48,60,77,94,107,<wbr>114,121,134,140,141,145,149,<wbr>132,149,-79,-55,-43,-22,-20,-<wbr>17,-9,5,27/)</div><div><br></div><div>in_obs=gc_inout(nav_lono,nav_<wbr>lato,lonC,latC)</div><div><br></div><div>mask_eurasia = where(in_obs.eq.True,1,0)</div><div>plot= gsn_csm_contour_map_polar(wks,<wbr>mask_eurasia,res)</div></div></div><div>--------</div><div>I’m attaching the resulting plot that I get.</div><div>Note that I have used this same gc_inout function to define other polygons in the Arctic and it works fine when the region was not over the central Arctic.</div><div><br></div><div>Any help would be appreciated.</div><div><br></div><div>Thanks,</div><div><br></div><div>Rym</div><div><br></div><div><div><div>------</div><div>Rym Msadek</div><div style="font-size:10px">CNRS-CERFACS</div><div style="font-size:10px">42 Avenue Gaspard Coriolis</div><div style="font-size:10px">31057 Toulouse</div></div><div style="font-size:10px">Tel: 05 61 19 31 92</div></div><div><img id="m_-2227748546265570724B265ED0D-1552-4833-8E6F-4693EF68E9A9" src="cid:8C0B0274-46E0-444A-8C43-ADBB1FEB6734" width="788" height="795"></div></div><br>______________________________<wbr>_________________<br>
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