Atmospheric balloon soundings have been made since the end of the 19th
century. In recent decades, specific upper-air radiosonde measurements
have become important for climate monitoring and atmospheric research.
Here we show profiles of solar and terrestrial radiation measured with
balloon-borne radiometers through cloud-free and cloudy atmospheres,
which experimentally demonstrate the greenhouse effect by water vapor in
the Earth’s atmosphere. Absorption and reflection of solar shortwave
radiation in the atmosphere and on the ground are shown. Thermal
longwave radiation, emitted from Earth’s surface and then absorbed and
reemitted in the atmosphere, shows varying absorption/reemission of
upward/downward longwave fluxes due to changing temperature and water
vapor. Clouds more strongly absorb upward and increase downward longwave
radiation. Thermal emission into space is shown to be reduced by water
vapor and clouds. Measured radiation profiles are compared to
numerically calculated radiation profiles.