Observations of the diurnal cycle of outgoing longwave radiation from the Geostationary Earth Radiation Budget instrument

Comer, R. E., Slingo, A. and Allan, R. P. ORCID: https://orcid.org/0000-0003-0264-9447 (2007) Observations of the diurnal cycle of outgoing longwave radiation from the Geostationary Earth Radiation Budget instrument. Geophysical Research Letters, 34 (2). L02823. ISSN 0094-8276 doi: 10.1029/2006GL028229

Abstract/Summary

The Geostationary Earth Radiation Budget instrument on Meteosat-8, located over Africa, provides unprecedented temporal sampling (~17 minutes) of the broadband emitted thermal and reflected solar radiances. We analyse the diurnal cycle of the outgoing longwave radiation (OLR) fluxes derived from the thermal radiances for July 2006. Principal component (PC) analysis separates the signals of the surface temperature response to solar heating and of the development of convective clouds. The first two PCs explain most of the OLR variations: PC1 (surface heating) explains 82.3% of the total variance and PC2 (cloud development) explains 12.8% of the variance. Convection is initiated preferentially over mountainous regions and the cloud then advects downstream in the ambient flow. Diurnal variations are much weaker over the oceans, but a coherent signal over the Gulf of Guinea suggests that the cloudiness is modulated by the diurnally varying contrast between the Gulf and the adjacent land mass.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/865
Identification Number/DOI	10.1029/2006GL028229
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Environmental Systems Science Centre
Publisher	American Geophysical Union
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