Abstract. The present work deals with two well-known databases of hourly
mean of solar irradiance that are derived from satellite imagery: the CAMS
Radiation Service version 3.2, abbreviated as CAMS-Rad and part of the
Copernicus Atmosphere Monitoring Service version 3.2 (CAMS), and the
HelioClim-3 version 5, abbreviated as HC3v5. It adds up to the continuous
documentation of these two databases that demonstrates that both databases
capture the temporal and spatial variability of the solar radiation and are
reliable sources of data. The spatial consistency of the uncertainties of
these databases is verified against measurements performed within a dense
network of ground stations in the Netherlands from the Royal Meteorological
Institute KNMI for the period 2014–2017. For the CAMS-Rad database, the correlation coefficients between ground
measurements and estimates are around 0.94–0.97 for irradiance E and
0.85–0.89 for clearness index KT. The bias ranges between −12 and
27 W m−2 (−4 % and 10 %). The standard deviation for E is
almost constant at all stations and around 67 W m−2 (24 %) except
at Valkenburg (57 W m−2, 20 %) and De Bilt (73 W m−2,
27 %). For this database, the statistical indicators are constant at
inland stations showing the spatial consistency of the performances of
CAMS-Rad dataset. At seashore stations, statistical indicators are more
variable. The sea proximity influences CAMS-Rad performances and a weak
spatial consistency is observed near seashore. For the HC3v5 database, the correlation coefficients are around 0.96–0.98
for E and 0.86–0.91 for KT. The bias ranges between −3 and 15 W m−2
(−1 % and 5 %). The standard deviation ranges between 48 (17 %)
and 60 W m−2 (22 %). It is constant at inland stations and around
54 W m−2 (20 %) with peaks at Ell (59 W m−2, 21 %) and
De Bilt (60 W m−2, 22 %). For this database, statistical
indicators are constant at all stations as a whole, showing a strong spatial
consistency of uncertainties. An exception is the standard deviation which
tends to decrease at the seashore stations and is close to 50 W m−2
(17 %); this could be related to the general trend of decreasing standard
deviation with increasing KT already reported in the scientific literature. As a whole, it is found that both databases are reliable sources on solar
radiation in the Netherlands.
Adversarial Search by Evolutionary Computation
