Testing several methods for the fusion of the two HelioClim-1 and-3 data sets of daily downwelling solar radiation at surface-Application to the creation of a new consistent 1985-2016 data set

Benoît Gschwind (1) , Lucien Wald (1)

1 O.I.E. - Centre Observation, Impacts, Énergie

The HelioClim-1 and-3 data sets provide satellite-derived estimates of the daily downwelling solar radiation at the surface at different spatial and temporal resolutions and different periods with an overlap of 23 months in 2004-2005. Eight methods are tested for fusing HelioClim-1 and-3 to create an enhanced version HC1e of HelioClim-1 having a better accuracy. The methods apply to the irradiation as well as to the clearness index KT and include adjustment by addition, ratioing, affine transforms, and quantile mapping. The comparison with measurements performed at nine meteorological stations for the period 1985-2003 reveals that the affine transform and quantile mapping of KT yield the best results. As an application, a new data set, called SSRD-H3E, has been created by the concatenation of HC1e and HelioClim-3 using the quantile mapping of KT technique. It offers daily mean of irradiance at the surface and at the top-of-the-atmosphere over 1985-2016 with a spatial resolution of 0.25°. When compared to the measurements at the nine stations from 1985 to 2016, the standard deviation of errors is less than 29 W m-2 (250 J cm-2 for daily irradiation); the correlation coefficient is always greater than 0.92.

Domaines: Océan, Atmosphère; Climatologie

Benoît Gschwind, Lucien Wald. Testing several methods for the fusion of the two HelioClim-1 and-3 data sets of daily downwelling solar radiation at surface-Application to the creation of a new consistent 1985-2016 data set. [Research Report] Mines ParisTech - PSL University. 2019. ⟨hal-02051697⟩