| dc.description.abstract | Conventional radiosonde wind observations and geopotential
heights have been used to prepare ten-year mean motion field
and thickness patterns over the African continent and its
immediate neighborhood. Data for 75 radiosonde stations
were used. Streamlines and isotach analyses were carried
out for the six standard pressure levels of 850mb, 700mb,lOOmb during the four months of January (northern autmn) April (northern spring), July (northern summer)
and October (northern autumn). The thickness for the
layers 8S0-l00mb, 850-500mb and 500-l00mb were determined
at each station and analyses of isopleths of thickness
carried out.To obtain the divergence 'and vorticity fields, grid
values of wind ,at 2.50 interval were used to compute divergence
and vorticity. The relaxation method with boundary condition
values as those suggested by Mukut B. Mathur (1972) were
used to obtain velocity potential and str~amtunction fields
from divergence and vorticity values respectively. A
comparison of the meridional divergent part of the \find and
zonal rotational part of the wind with the observed meridional
and zonal wind components respectively is made. Spectral and
harmonic analyses of the zonal and meridional_wind components
and thickness values are performed. | en |
