NCL入门

；***这两行指令必须加载，类似于c语言中的库函数
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"begin              ；开始标志
a = addfile("/home/yuanm/surface.nc","r")        ；文件读取
; 绘图类型（依次为，窗口显示，pdf，ps,ncgm格式）type = "x11"
;  type = "pdf"
; type = "ps"
; type = "ncgm"wks = gsn_open_wks(type,"ECMWF_surface")      ；创建工作空间
; 时间维数（如该例子中，只有00，08，16，24四个时间段）times = a->time   ; 箭头表示数据a中的时间向量ntimes = dimsizes(times)         ; 时间维数
；循环结构do it = 0,(ntimes-1),1msl1 = a->msl(it,:,:)      ; mean sea level pressuret2m1 = a->t2m(it,:,:)      ; temperature at 2mu101 = a->u10(it,:,:)      ; 10 metre U wind componentv101 = a->v10(it,:,:)      ; 10 metre V wind componentmsl = short2flt(msl1)    ；数据类型转换msl = smth9(msl,0.50,0.25,False)   ；平滑t2m = short2flt(t2m1)t2m = smth9(t2m,0.50,0.25,False)t2m = t2m-273.15u10 = short2flt(u101)v10 = short2flt(v101)msl = msl/100.msl@units="hPa"；绘图参数控制res                 = Trueres@gsnDraw         = False        ；为调整绘制顺序，让该图暂时不画出来res@gsnFrame        = False
;  res@gsnMaximize     = True    ; Maximize plot in frame
; Add map resources
;  res@mpGridAndLimbOn       =  True                ; Turn off lat/lon lines
; res@mpGridLineColor       = "gray"res@mpGeophysicalLineColor = "gray"res@pmTickMarkDisplayMode = "Conditional"             ; Turn on map tickmarksres@mpMaxLonF     = 180.        ；经度最大值res@mpMinLonF     = 100.          res@mpMaxLatF     = 50.       res@mpMinLatF     = -10.       res@mpFillOn           = False
; 温度场绘图res2 = Trueres2 = resres2@cnFillOn            = Trueres2@cnLinesOn           = Falseres2@cnInfoLabelOn = Falseres2@cnLevelSelectionMode = "ManualLevels"res2@cnMinLevelValF       = 0.0res2@cnMaxLevelValF       = 40.0res2@cnLevelSpacingF      = 2.0res2@gsnLeftString ="  "res2@gsnRightString = "  "map1 = gsn_csm_contour_map(wks,t2m,res2)draw(map1)delete(res2)
; Set some contouring resources.res1    =  Trueres1 = resres1@cnFillOn        = Falseres1@cnLineLabelsOn  = True
;  res1@cnLineLabelFontAspectF  = 0.6res1@cnLineLabelFontColor = "blue"res1@cnLineLabelPerimOn = Falseres1@cnLineLabelPlacementMode = "Constant"
;  res1@cnLineLabelConstantSpacingF = 1.0res1@cnLineLabelInterval = 1.0
;  res1@cnLineDashSegLenF = 0.20res1@cnInfoLabelOn   = False
;  res1@cnLevelSelectionMode = "ExplicitLevels"
;  res1@cnLevels = (/5800.,5840.,5850.,5860.,5870.,5880.,5890.,5900./)res1@cnLevelSpacingF  = 2.0
;  res1@cnHighLabelsOn   = True
;  res1@cnHighLabelString          = "H"res1@cnHighLabelBackgroundColor = -1res1@cnHighLabelFontColor       = "blue"
;  res1@cnHighLabelFontAspectF     = 5.0
;  res1@cnLowLabelsOn   = True
;  res1@cnLowLabelString          = "L"res1@cnLowLabelBackgroundColor = -1res1@cnLowLabelFontColor       = "red"res1@cnLowLabelFontAspectF     = 2.0res1@cnLineColor = "Blue"res1@gsnContourLineThicknessesScale = 3.0res1@gsnLeftString = ""res1@gsnRightString = ""map = gsn_csm_contour_map(wks,msl, res1)draw(map)delete(res1);create vector plotres3 = Trueres3 = resres3@vcRefMagnitudeF= 20.0res3@vcRefLengthF= 0.05res3@vcMinDistanceF= 0.03res3@vcGlyphStyle= "CurlyVector"res3@vcRefAnnoOn = True   ;do not draw reference vector annotationres3@vcRefAnnoOrthogonalPosF = -0.15  ; vertical positionres3@vcRefAnnoParallelPosF = 0.98res3@vcLineArrowThicknessF = 2.0res3@gsnDraw = Falseres3@gsnFrame = Falseres3@gsnLeftString = " "res3@gsnRightString = " "map2= gsn_csm_vector_map(wks,u10,v10,res3)draw(map2)delete(res3)frame(wks)
end do
end

注：

grib资料与ncl资料大同小异，都是先提取变量，然后做数据处理。

变量查看指令：ncl_filedump  "资料名“（如"surface.nal")

然后根据所查看到的变量信息提取变量。