tvmap problem

[yangning-code]

How to use tvmap to display the longitude numbers when drawing a polar map, just like the latitude numbers in the attachment?

tvmap,o3_cm_tvmap,lon_model_2_25,lat_model_2_25,$
color=1,divisions=5,Csfac=2.0,TCsfac=2.0,/fcontour,$
continents=1,coasts=1,grid=1,countries=1,/sample,Thick=2,$
Margin=[0.05,0.01,0.05,0.10],$;cbformat='(F5.1)',$
cbar=1,NoGXlabels=0,NoGYlabels=0,polar=1,ccolor=1,$
cbunit='ppbv',title='test',$
c_level=[0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75],$
C_ANNOTATION=1,$
; limit=[15,70,55,140],$;charsize=1.4,$
noadvance=1;,cbposition=[0.05,0.05,0.9,0.1];position=[0.1,0.1,0.9,0.9]
multipanel,/advance