58 A WORLD ATLAS OF ATMOSPHERIC RADIO REFRACTIVITY 



180 150 



90 60 



30 



30 60 



90 120 150 180 



180 150 120 90 



60 30 



90 120 150 180 



Figure B-12. Monthly mean AN: November. 



90 120 150 180 



180 150 120 90 



60 30 



90 120 150 180 



Figure B-13. Monthly mean AN: December. 



