It is mainly because of the winds effect. Here is the link from internet

Just like we said, it is mainly because of the winds. But the directions of the winds are not simply from the earth rotation. Here is another link about the winds

 

Also to Zhang Rui, we can regard the system as inertial system, since the angular velocity induced force is very small compared with the gravity. I did the calculation

rotation acceration is about  10 e-5 which is much smaller than g=9.8.

 

Well it is a nice discussion with you guys!

 

Liguo

rui zhang <zhruirui@...> wrote: