SAN FRANCISCO STATE UNIVERSITY                     METEOROLOGY 403                                  DEPARTMENT OF GEOSCIENCES                            Fall 2004

 

Inclass Exercise No. 4

 

Dine’s Compensation

 

       On a given day, a trough in the westerlies is progressing across the United States.  At the inflection point on the eastern side of the trough, the net divergence in the layer from the LND to the tropopause was 2.78 X 10 –5 s -1.  The LND was at the 500 mb level an, on this day, the Tropopause was approximately located at the 300 mb level.  Also, at the inflection point, the 500 mb height was 546 dm and the 300 mb height was 943 dm.   

 

Determine the vertical velocity at the LND in cm s-1.

 

                                  (1)

 

 

                            (2)

 

For the problem level 2 is 300 mb and level 1 is 500 mb.

 

 

and since the vertical velocity at 300 mb is zero.

 

 

z300 = 9430 m;  z500=5460 m

 

Hence

 

w500 = (2.78 X 10-5 s-1) (3970 m) = 11 cm s-1