  Clouds affected by solar eclipses could influence the reflection of sunlight
back into space and might change local precipitation patterns. Satellite cloud
retrievals have so far not taken into account the lunar shadow, hindering a
reliable spaceborne assessment of the eclipse-induced cloud evolution. Here we
use satellite cloud measurements during three solar eclipses between 2005 and
2016 that have been corrected for the partial lunar shadow together with
large-eddy simulations to analyze the eclipse-induced cloud evolution. Our
corrected data reveal that, over cooling land surfaces, shallow cumulus clouds
start to disappear at very small solar obscurations. Our simulations explain
that the cloud response was delayed and was initiated at even smaller solar
obscurations. We demonstrate that neglecting the disappearance of clouds during
a solar eclipse could lead to a considerable overestimation of the
eclipse-related reduction of net incoming solar radiation. These findings
should spur cloud model simulations of the direct consequences of
sunlight-intercepting geoengineering proposals, for which our results serve as
a unique benchmark.
