ncl 设置经纬度字体大小

您可以使用NCL的gsn_text函数来设置经纬度标签的字体大小。以下是一个简单的例子：

begin
  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"

  ;生成一些随机数据
  lon = fspan(-180, 180, 37)
  lat = fspan(-90, 90, 19)
  data = random_uniform(lon, lat)

  ;创建一个图形
  wks = gsn_open_wks("png", "plot")

  ;设置地图视图
  res                    =  True
  res@gsnMaxLatF         =  80
  res@gsnMinLatF         = -80
  res@gsnMaxLonF         =  180
  res@gsnMinLonF         = -180
  res@gsnAddCyclic       =  False
  res@mpProjection       = "Stereographic"
  res@mpCenterLonF       =  0
  res@mpCenterLatF       =  90
  res@mpOutlineOn        =  True
  res@mpFillOn           =  True
  res@mpLandFillColor   = "gray75"
  res@mpOceanFillColor  = "white"
  res@mpInlandWaterFillColor = "white"
  res@mpGridAndLimbOn    =  True
  res@mpGridLineColor    = "gray50"
  res@mpLabelsOn         =  True
  res@mpLabelFontHeightF =  0.015 ; 设置字体大小
  res@mpLeftCornerLatF   = -90
  res@mpRightCornerLatF  =  90
  res@mpLeftCornerLonF   = -180
  res@mpRightCornerLonF  =  180

  ;绘制地图
  map = gsn_csm_map(wks, res)

  ;添加数据轮廓
  res@cnFillOn           =  True
  res@cnFillMode         = "RasterFill"
  res@cnLinesOn          =  False
  res@cnLineLabelsOn     =  False
  res@cnLevelSelectionMode = "ManualLevels"
  res@cnMinLevelValF     =  0
  res@cnMaxLevelValF     =  1
  res@cnLevelSpacingF    =  0.1
  res@cnFillPalette      = "MPL_viridis"
  res@cnMonoLineDashPatterns = False
  res@cnRasterSmoothingOn = True
  res@cnRasterSmoothingFactorF = 0.25
  plot = gsn_csm_contour_map(wks, data, res)

  ;关闭图形设备
  gsn_panel(wks, (/map,plot/), (/1,2/), False) ;将两个图形并排显示
  gsn_draw(wks)
  frame(wks)
end

在上述代码中，我们使用`res@mpLabelFontHeightF = 0.015`设置经纬度标签的字体大小为0.015。您可以根据需要将此值更改为适当的大小。