A PROPOSED MECHANISM OF FALL WINDS AND DASHIKAZE

Using observed results, the some characters of the fall winds and the Dashikaze (i.e. winds that blow out of the narrow valley) are described, and the existence of an inversion layer above is emphasized. On the basis of these facts an averaged system of equations of air flow under the inversion is derived and then the natures of steady flow in the channel with variable width and height of the bottom are studied. As a result the flows over the mountain and through the narrow valley are found to be affected in the same way, and if the difference in the inversion height exists between windward and lee of these obstacles, then the violent wind may arise in the lee side (or exit part). It is shown that the above theoretical results agree qualitatively very well with some observed results. © 1968, Japan Meteorological Agency. All rights reserved.