Forces on the top of a bullet train

[cbram]

Can anyone tell me what is the air resistance on the top of a bullet train when it is moving at top speed

 

[billy_joule]

There will be skin friction on the roof surface of the train:

http://en.wikipedia.org/wiki/Parasitic_drag#Skin_friction

Is that what you are interested in? I can't see the use of calculating drag for the roof alone... Though, If you make an attempt we can help you solve the problem.