<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi,<div class=""><br class=""></div><div class="">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 class="">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 class=""><div class=""><br class=""></div><div class="">Here are the lon lat that define my polygon, over the Eurasian basin of the Arctic.</div><div class="">---------</div><div class=""><div class="">latC=(/81,81.5,82,82.7,82.4,81.6,80,78.8,77,78,79,81,82,84,88,88.5,89,86,85,85,84,83,82,82,81/)</div><div class="">lonC=(/27,36,48,60,77,94,107,114,121,134,140,141,145,149,132,149,-79,-55,-43,-22,-20,-17,-9,5,27/)</div><div class=""><br class=""></div><div class="">in_obs=gc_inout(nav_lono,nav_lato,lonC,latC)</div><div class=""><br class=""></div><div class="">mask_eurasia = where(in_obs.eq.True,1,0)</div><div class="">plot= gsn_csm_contour_map_polar(wks,mask_eurasia,res)</div></div></div><div class="">--------</div><div class="">I’m attaching the resulting plot that I get.</div><div class="">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 class=""><br class=""></div><div class="">Any help would be appreciated.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class=""><br class=""></div><div class="">Rym</div><div class=""><br class=""></div><div class=""><div class=""><div class="">------</div><div class="">Rym Msadek</div><div class="" style="font-size: 10px;">CNRS-CERFACS</div><div class="" style="font-size: 10px;">42 Avenue Gaspard Coriolis</div><div class="" style="font-size: 10px;">31057 Toulouse</div></div><div class="" style="font-size: 10px;">Tel: 05 61 19 31 92</div></div><div class=""><img height="795" width="788" apple-width="yes" apple-height="yes" apple-inline="yes" id="B265ED0D-1552-4833-8E6F-4693EF68E9A9" src="cid:8C0B0274-46E0-444A-8C43-ADBB1FEB6734" class=""></div></body></html>