Imperial College London

Dr Helen Brindley

Faculty of Natural SciencesDepartment of Physics

Reader in Earth Observation



+44 (0)20 7594 7673h.brindley




717Huxley BuildingSouth Kensington Campus






BibTex format

author = {Gristey, JJ and Chiu, JC and Gurney, RJ and Morcrette, CJ and Hill, PG and Russell, JE and Brindley, HE},
doi = {10.5194/acp-18-5129-2018},
pages = {5129--5145},
title = {Insights into the diurnal cycle of global Earth outgoing radiation using a numerical weather prediction model},
url = {},
volume = {18},
year = {2018}

RIS format (EndNote, RefMan)

AB - A globally complete, high temporal resolution and multiple-variable approach is employed to analyse the diurnal cycle of Earth's outgoing energy flows. This is made possible via the use of Met Office model output for September 2010 that is assessed alongside regional satellite observations throughout. Principal component analysis applied to the long-wave component of modelled outgoing radiation reveals dominant diurnal patterns related to land surface heating and convective cloud development, respectively explaining 68.5 and 16.0% of the variance at the global scale. The total variance explained by these first two patterns is markedly less than previous regional estimates from observations, and this analysis suggests that around half of the difference relates to the lack of global coverage in the observations. The first pattern is strongly and simultaneously coupled to the land surface temperature diurnal variations. The second pattern is strongly coupled to the cloud water content and height diurnal variations, but lags the cloud variations by several hours. We suggest that the mechanism controlling the delay is a moistening of the upper troposphere due to the evaporation of anvil cloud. The short-wave component of modelled outgoing radiation, analysed in terms of albedo, exhibits a very dominant pattern explaining 88.4% of the variance that is related to the angle of incoming solar radiation, and a second pattern explaining 6.7% of the variance that is related to compensating effects from convective cloud development and marine stratocumulus cloud dissipation. Similar patterns are found in regional satellite observations, but with slightly different timings due to known model biases. The first pattern is controlled by changes in surface and cloud albedo, and Rayleigh and aerosol scattering. The second pattern is strongly coupled to the diurnal variations in both cloud water content and height in convective regions but only cloud water content in marine stratocu
AU - Gristey,JJ
AU - Chiu,JC
AU - Gurney,RJ
AU - Morcrette,CJ
AU - Hill,PG
AU - Russell,JE
AU - Brindley,HE
DO - 10.5194/acp-18-5129-2018
EP - 5145
PY - 2018///
SN - 1680-7316
SP - 5129
TI - Insights into the diurnal cycle of global Earth outgoing radiation using a numerical weather prediction model
UR -
UR -
UR -
VL - 18
ER -