S m YFrom time series of closely-spaced upper-wind (pilot-balloon) measurements in the rear of synoptic lines of wind shift and cooling, the configuration of the elevated wind-shear layer and the strength of the flow beneath are deduced. The height of the shear layer does not rise uniformly with time, but at one stage remains constant or decreases, before resuming a sustained rise. It is demonstrated by the method of dynamic similarity that this phenomenon is broadly the counterpart of the friction head on density surges in stratified liquids.Cumulative inflow into the advancing wedge of cold air is compared with the total mass in the cold air wedge and found to be generally in excess of this, the exceptions occurring with sea-breezes or analogous phenomena on a larger scale (coastal fronts). In one case where sufficient observations are available, vertical velocities are computed. The excess inflow is shown to be associated with a vertical circulation involving considerable mass transfer upward across the shear zone.
A study has been made of the conditions for seasonal balance of zonal angular momentum, during Southern summer, in the troposphere overlying the equatorial (monsoonal) westerlies. The observational data are not adequate to determine the finer details of balance. It is shown that by and large it can be accounted for by zonal pressure gradients and meridional transport of Earth's angular or Ω‐momentum (a Coriolis effect). Zonal and meridional stresses due to advective and eddy transports of relative zonal or ū‐momentum as well as the surface frictional stresses are of considerably smaller magnitude. This confirms for a monsoonal region the conclusions of Palmer (1958), from observations in the North Pacific in June, that quasi‐geostrophic equilibrium occurs down to very low latitudes above the planetary friction layer. The high‐level easterly jet stream is shown to play an important part in two aspects of balance.
grew up speaking Swedish with his mother and Polish with his father, Arthur Josef Berson, who was a prominent meteorologist in the early years of the century. Berson senior worked at the Lindenberg Observatory in Germany; he gained fame as a balloonist and by his discovery of the highlevel equatorial "Berson Westerlies," later recognized as forming, together with the F. A. Berson (Sweden, 1947) "Krakatoa Easterlies," the "Biennial Oscillation." Andrzej Berson decided to study meteorology in 1929 after his father had dissuaded him from going into journalism, saying "it is weather you have made your interest; one does not just "become a journalist." The following extracts from the reminiscences of the younger Berson relate to some of the century's most prominent meteorologists and have been placed into context with the help of the author by Uwe Radok.
Mean monthly meridional and zonal circulations in the region of the Indonesia‐Australia summer monsoon and associated transfers of heat energy are investigated using upper air soundings, rainfall and other data from two seasons. Daily sounding data are used to determine also the eddy flux of latent heat. A large increase of meridional circulation strength and energy transfer from November to December on the northern side of the monsoonal trough suggests that establishment of the regime is associated with a comparatively abrupt southward shift and intensification of the Northern Hadley cell in the relevant longitude sector. When the monsoon has become established latent heat relase in the region exceeds net export of sensible heat from it by a comparatively small amount. These quantities dominate the remaining ones in the heat balance, viz. net radiative cooling in the troposphere and sensible heat transfer from the ocean. Items in the heat budget are compared with those obtaining during the pre‐monsoonal regime in the area and on the winter side of the equatorial trough zone at large, the latter according to Riehl and Malkus (1959). Gain of sensible heat is also assessed separately for the lower and upper troposphere in terms of gain or loss of internal energy, the work done by horizontal pressure gradient forces and by vertical pressure gradient forces (gain of potential energy). The vertical upward flux of energy across mid‐tropospheric level is deduced and the importance of buoyancy in bringing about this flux is indicated.
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