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

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Comer, Ruth E ; Slingo, Anthony ; Allan, Richard P (2007)

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.
  • References (20)
    20 references, page 1 of 2

    Allan, R. P., A. Slingo, S. F. Milton, and I. Culverwell (2005), Exploitation of Geostationary Earth Radiation Budget data using simulations from a numerical weather prediction model: Methodology and data validation, J. Geophys. Res., 110, D14111, doi:10.1029/2004JD005698.

    Barkstrom, B., et al. (1989), Earth Radiation Budget Experiment (ERBE) archival and April 1985 results, Bull. Am. Meteorol. Soc., 70, 1254 - 1262.

    Ciesielski, P., W. Schubert, and R. Johnson (2001), Diurnal variability of the marine boundary layer during ASTEX, J. Atmos. Sci., 58, 2355 - 2376.

    Cohen, J., M. S. Dias, and C. Nobre (1995), Environmental conditions associated with Amazonian squall lines: A case study, Mon. Weather Rev., 123, 3163 - 3174.

    Comer, R. E., A. Slingo, and R. P. Allan (2006), The diurnal cycle observed by Meteosat-8 and simulated by a climate model, paper presented at EUMETSAT Meteorological Satellites Conference, Finnish Meteorol. Inst., Helsinki, 12 - 16 Jun.

    Desbois, M., T. Kayiranga, B. Gnamien, S. Guessous, and L. Picon (1988), Characterization of some elements of the Sahelian climate and their interannual variations for July 1983, 1984 and 1985 from the analysis of METEOSAT ISCCP data, J. Clim., 1, 867 - 904.

    Duvel, J. (1989), Convection over tropical Africa and the Atlantic Ocean during northern summer. part I: Interannual and diurnal variations, Mon. Weather Rev., 117, 2782 - 2799.

    Garreaud, R., and J. Wallace (1997), The diurnal march of convective cloudiness over the Americas, Mon. Weather Rev., 125, 3157 - 3171.

    Gube, M. (1982), Radiation budget parameters at the top of the Earth's atmosphere derived from METEOSAT data, J. Appl. Meteorol., 21, 1907 - 1921.

    Harries, J., et al. (2005), The Geostationary Earth Radiation Budget (GERB) project, Bull. Am. Meteorol. Soc., 86, 945 - 960.

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