Persistent cloud cover over mega-cities linked to surface heat release

Theeuwes, N. E. ORCID: https://orcid.org/0000-0002-9277-8551, Barlow, J. F., Teuling, A. J., Grimmond, C. S. B. ORCID: https://orcid.org/0000-0002-3166-9415 and Kotthaus, S. (2019) Persistent cloud cover over mega-cities linked to surface heat release. npj Climate and Atmospheric Science, 2. 15. ISSN 2397-3722 doi: 10.1038/s41612-019-0072-x

Abstract/Summary

Urban areas are a hotspot for the interactions between the built environment, its inhabitants, and weather. Unlike the impact of temperatures through the well-known urban heat island effect, urban effects on cloud formation remain unknown. In this study we show observational evidence of a systematic enhancement of cloud cover in the afternoon and evening over two large metropolitan areas in Europe (Paris and London). Long-term measurements in and around London show that during late-spring and summer, even though less moisture is available at the surface and the atmosphere is drier, low clouds can persist longer over the urban area as vertical mixing of the available moisture is maintained for a longer period of time, into the evening transition. Our findings show that urban impacts on weather extend beyond temperature effects. These prolonged clouds over the city might enhance the urban heat island via night-time radiative forcing.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/83524
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Nature Publishing Group
Download/View statistics	View download statistics for this item