NCL画地面气压场与PYTHON以及实况不一致

指甲钳

用FNL资料画海平面气压，出来和实况相差很远。但让同事用PYTHON画的又与实况一样。请问是我的脚本哪里有问题啊？
; These files are loaded by default in NCL V6.2.0 and newer
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
begin
  ;在“ ”中输入数据所在地址
  g = addfile("e:/data/baoyu/fnl_20240229_12_00.grib2","r")
  shp_filename = "gis/guangdong/guangdong.shp"

;设置高度
  nlev=1000

;读取数据
  lon0 = g->lon_0
  lat0 = g->lat_0
  pres = g->PRMSL_P0_L101_GLL0(::,::)
  press = pres/100
  u   = g->UGRD_P0_L103_GLL0({10},::4,::4)
  v   = g->VGRD_P0_L103_GLL0({10},::4,::4)

  ;lon0 = g->longitude
  ;lat0 = g->latitude
  ;pres = g->msl(0,:,:)
  ;press = pres/100
;u   = g->u10(0,:,:)
; v   = g->v10(0,:,:)


;读取时间
time = pres@initial_time
;yyyymmddhh    = cd_calendar(time, 3)
DATE = grib_stime2itime (time)
;print (yyymmmdddhh)
;>---------------------------------------<
;>---------------------------------------<
;      设置图片格式和文件名
;>---------------------------------------<
wks = gsn_open_wks("png","Sea-level Pressure")  
res = True
res@gsnDraw = False
res@gsnFrame = False
res@gsnLeftString = ""
res@gsnRightString = ""


;>---------------------------------------<
;>---------------------------------------<
;      等值线设置
;>---------------------------------------<
cnres = res
;cnres@cnSmoothingOn = True ;
;cnres@cnSmoothingDistanceF   = 0.001
cnres@cnLevelSelectionMode   = "ManualLevels"
cnres@cnMinLevelValF = 870.0
cnres@cnMaxLevelValF = 1080.0
cnres@cnLevelSpacingF = 2.5
cnres@cnInfoLabelOn = False
cnres@cnLineLabelsOn          =  True
cnres@cnLineLabelFontHeightF = 0.01
cnres@cnLineThicknessF = 2.0
cnres@cnLineLabelInterval = 2
cnres@cnLineColor         = "red"
cnres@cnHighLabelsOn      = True
cnres@cnHighLabelString   = "H"
cnres@cnHighLabelFontColor = "BLUE"
cnres@cnLowLabelsOn       = True
cnres@cnLowLabelString   = "D"
cnres@cnLowLabelFontColor = "RED"

;>---------------------------------------<
;>---------------------------------------<
;     标题设置
;>---------------------------------------<

cnres@tiMainOn                 = False
cnres@gsnLeftString                 = "Sea-level Pressure"
;cnres@gsnRightString                 = DATE


;>---------------------------------------<
;>---------------------------------------<
;     风向杆设置
;>---------------------------------------<
u = u*2.5
v = v*2.5
vcres                           = res
vcres@gsnAddCyclic = False
vcres@vcRefMagnitudeF         = 50. ;调整箭头大小？
vcres@vcRefLengthF            = 0.02           
vcres@vcGlyphStyle               = "WindBarb"
vcres@vcMinDistanceF            =1
vcres@vcRefAnnoOn               = False
vcres@vcWindBarbLineThicknessF  = 1.5
vcres@vcMinMagnitudeF = 0.01
vcres@vcWindBarbTickLengthF = 0.5
vcres@vcWindBarbLineThicknessF = 3
vcres@vcWindBarbTickSpacingF   = 0
vcres@vcWindBarbColor          = "BLUE"


;>---------------------------------------<
;            地图设置
;>---------------------------------------<
mpres = res
mpres@mpFillOn                = False
mpres@mpMinLatF               = 10.
mpres@mpMaxLatF               = 70.
mpres@mpMinLonF               = 80.
mpres@mpMaxLonF               = 150.
mpres@mpDataBaseVersion       = "MediumRes"
mpres@mpDataSetName           = "Earth..4"
mpres@mpOutlineSpecifiers     = (/"China:states"/)
mpres@pmTickMarkDisplayMode  = "Always"
mpres@tmXBMajorLengthF = 0.005

;mpres@mpProjection = "LambertConformal"   ;兰伯特投影
;mpres@mpLambertMeridianF = 110.0
;mpres@mpLambertParallel1F = .001      ;Default: .001 ;可以自己改一改，看看投影有什么不同，挺有趣的
;mpres@mpLambertParallel2F = 89.999    ;Default: 89.999



mapplot = gsn_csm_map(wks, mpres)
cnplot = gsn_csm_contour(wks, press, cnres)
vcplot = gsn_csm_vector(wks, u, v, vcres)

;>---------------------------------------<

;>---------------------------------------<
;>---------------------------------------<
;     广东地区
;>---------------------------------------<
;lnres                  = True
;lnres@gsLineColor      = "black"
;lnres@gsLineThicknessF = 2.0
;line_mask = gsn_add_shapefile_polylines(wks, cnplot, shp_filename, lnres)


overlay(mapplot, cnplot)
overlay(mapplot, vcplot)
draw(mapplot)
frame(wks)
end

PYTHON

NCL海平面气压场

实况海平面气压场