摘要：The atmosphere's fair weather electric field is a permanent feature, arising from the
combination of distant thunderstorms, Earth's conducting surface, a charged ionosphere
and cosmic ray ionization. Despite its ubiquity, no fair weather electricity effect on
clouds has been hitherto demonstrated. Here we report surface measurements of
radiation emitted and scattered by extensive thin continental cloud, which, after
~2 min delay, shows changes closely following the fair weather electric field. For typical
fluctuations in the fair weather electric field, changes of about 10% are subsequently
induced in the diffuse short-wave radiation. These observations are consistent with
enhanced production of large cloud droplets from charging at layer cloud edges.
