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</o:shapelayout></xml><![endif]--></head><body lang=FR link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am using merra-2 data U&V wind speeds at 50m, for wind energy studies in France ; very good data…..<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Getting « MERRA2_400.tavg1_2d_slv_Nx.%y4%m2%d2.SUB.nc4» daily files, data are obtained with grads, using xdfopen and enclosed data descriptor files.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I really don’t understand why i get different values with different descriptor files, for same point and time :<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As an example, at point (49°N ; 4.375°E) and time 2017-12-01 at 0h, i get U50m=5.31 m/s using « merra2_dec2017.ctl » (lat = 49, lon = 4.375, t = 1), and U50m=5.22 m/s using « merra2_2017.ctl » (lat = 49, lon = 4.375, t=8017)…..<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Why ????????????????<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks !<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='mso-fareast-language:FR'>Antoine Molin<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:FR'>Etudes de vent PlenR<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:FR'>Tel : 03 20 47 99 76<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>