NCL 再分析资料 mask青藏高原的问题

追风的阳光

想mask青藏高原，
出现错误提示：
fatal:ContourPlotDraw: coordinates are out of range for drawing over a map: standard line or line label rendering method will not work;
consider setting the resource trGridType to "TriangularMesh" if coordinates contain missing values
请问是什么原因呢。。谢谢！（注释 HMask =mask(H,ter.gt.H,False)的话，没有报错，但是UMask = mask(U,ter.gt.H,False)
VMask = mask(V,ter.gt.H,False)不起作用）


;---Now get the 850hPa level
nl  = 20
H=in->HGT_3_ISBL(nl,:,:)
T=in->TMP_3_ISBL(nl,:,:)
U=in->U_GRD_3_ISBL(nl,:,:)
V=in->V_GRD_3_ISBL(nl,:,:)
ter=in->HGT_3_SFC(:,:)
print(ter)
UMask = mask(U,ter.gt.H,False)
VMask = mask(V,ter.gt.H,False)
HMask =mask(H,ter.gt.H,False)
.......
contour_h = gsn_csm_contour(wks,HMask,slp_res)
.......
vector = gsn_csm_vector(wks,UMask,VMask,vec_res)
.......
mpid = gsn_csm_map(wks,mpres)

; Overlay contour, and vector plots on the map plot.
  overlay(mpid,contour_h)
  overlay(mpid,vector)
  maximize_output(wks,True)