Welcome to the CPL Meteorology question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
Actual and Gradient Wind
Sky_Guy created the topic: Actual and Gradient Wind
At which latitude would there be the greatest difference between the actual and the gradient wind at 5000ft AGL?
A.15 degrees S
B.5 degrees S
C.25 degrees S
D.35 degrees S
can somebody please explain me why the answer is B.
bobtait replied the topic: Actual and Gradient Wind
The gradient wind is an imaginary wind that blows in response to the pressure gradient and Coriolis force when the relative strengths of these forces causes the resulting air flow to be parallel to curved isobars. The pressure gradient force acts at right angles to the isobars and directly out of a high pressure system and into a low pressure system. Coriolis force acts to swing the air to the left as it moves in the southern hemisphere.
However, Coriolis force is not constant and varies with latitude. It is strongest at the poles and zero at the equator. Air at or near the equator will be affected most by the pressure gradient and almost not at all by the Coriolis force. It will therefore flow much more acutely across the isobars out of a high and into a low. The answer to the question is the latitude that is closest to the equator.