title: The solar eclipse: a natural meteorological experiment.
abstract: A solar eclipse provides a well-characterized reduction in solar radiation, of calculable amount and duration. This captivating natural astronomical phenomenon is ideally suited to science outreach activities, but the predictability of the change in solar radiation also provides unusual conditions for assessing the atmospheric response to a known stimulus. Modern automatic observing networks used for weather forecasting and atmospheric research have dense spatial coverage, so the quantitative meteorological responses to an eclipse can now be evaluated with excellent space and time resolution. Numerical models representing the atmosphere at high spatial resolution can also be used to predict eclipse-related changes and interpret the observations. Combining the models with measurements yields the elements of a controlled atmospheric experiment on a regional scale (10-1000 km), which is almost impossible to achieve by other means. This modern approach to 'eclipse meteorology' as identified here can ultimately improve weather prediction models and be used to plan for transient reductions in renewable electricity generation. During the 20 March 2015 eclipse, UK electrical energy demand increased by about 3 GWh (11 TJ) or about 4%, alongside reductions in the wind and photovoltaic electrical energy generation of 1.5 GWh (5.5 TJ).This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.
authors.affiliation: Department of Meteorology, University of Reading, PO Box 239, Reading RG6 6BB, UK r.g.harrison@reading.ac.uk.
authors.forename: R Giles
authors.identifier: http://orcid.org/0000-0003-0693-347X
authors.initials: RG
authors.lastname: Harrison
authors.affiliation: Department of Geography, University of Sheffield, Winter Street, Sheffield S10 2TN, UK.
authors.forename: Edward
authors.identifier: http://orcid.org/0000-0002-8683-182X
authors.initials: E
authors.lastname: Hanna
keywords: citizen science; eclipse meteorology; renewable power generation; science outreach; weather forecasting