The in situ observations of the solar wind in the interplanetary mediu
m show a spectral break in the power density spectra. Bavassano (1990)
showed that near the Sun most of the fluctuations are propagating out
ward with respect to the Sun, indicating that the fluctuations observe
d originate from the Sun. Jatenco-Pereira & Opher (1989c, hereafter JP
O) used nonthermal mechanisms, such as Alfven waves, to explain corona
l heating and the origin of the solar wind. A single average frequency
for the Alfven waves was used. On the other hand, Tu (1987) tried to
explain the spectral break in the power density in the interplanetary
medium in the solar wind but did not treat coronal heating or the orig
in of the solar wind. No previous attempt has been made to explain the
spectral break in the power density spectra. We here obtain the coron
al heating, wind velocity, and power density of Alfven waves with a sp
ectral break compatible with observations, using the JPO model for the
Sun with a frequency- dependent flux of Alfven waves.