The wind structure beneath warm fronts


  • C. S. Durst B.A.


Fourteen cases of warm fronts passing over the British Isles were selected and the winds observed by means of pilot balloons were compared with the geostrophic winds at various heights up to 10,000 ft. and at distances ranging up to 500 miles. The results were combined in order to get an average value of the departure from the geostrophic wind at certain points. An evaluation is made of the second order terms in the equations at these points, and it is concluded that in this region of a depression the departures from the geostrophic wind are primarily dependent on (a) the isallobaric term and (b) a term involving the velocity of the cold air away from the incoming warm air and the variation in that direction of the velocity of the air at right angles to that direction.