Dear sir,
As instructed, I had observed normal breathing in sukhasana pose. As you said I observed how air goes outside and comes inside - felt the touch of air with the inner wall of the nostrils and also felt the temperature of incoming air and outgoing air. The similar symptoms I observed during this breathing, however the symptoms are minor. As per my understanding I am trying to balance straight spine as well as crossed legs during the sukhana pose. Does this forceful balancing appears to be cause of concern?
I do in sukhana pose on house hold mat and on the floor. This is the only time I sit on the floor in once a day. During this pose, my ankles does not touch the floor. For better understanding my pose is similar to the picture below.

Source: http://www.abc-of-yoga.com/yogapractice/theeasypose.asp
Please suggest and do the needful.
Regards,
Krishna