Abstract
Abstract. A new method has been developed to estimate the global and direct solar irradiance in the UV-A and UV-B at ground level in cloud-free conditions. It is based on a resampling technique applied to the results of the k-distribution method and the correlated-k approximation of Kato et al. (1999) over the UV band. Its inputs are the aerosol properties and total column ozone that are produced by the Copernicus Atmosphere Monitoring Service (CAMS). The estimates from this new method have been compared to instantaneous measurements of global UV irradiances made in cloud-free conditions at five stations at high latitudes in various climates. For the UV-A irradiance, the bias ranges between −0.8 W m−2 (−3 % of the mean of all data) and −0.2 W m−2 (−1 %). The root mean square error (RMSE) ranges from 1.1 W m−2 (6 %) to 1.9 W m−2 (9 %). The coefficient of determination R2 is greater than 0.98. The bias for UV-B is between −0.04 W m−2 (−4 %) and 0.08 W m−2 (+13 %) and the RMSE is 0.1 W m−2 (between 12 and 18 %). R2 ranges between 0.97 and 0.99. This work demonstrates the quality of the proposed method combined with the CAMS products. Improvements, especially in the modeling of the reflectivity of the Earth's surface in the UV region, are necessary prior to its inclusion into an operational tool.
Highlights
Solar ultraviolet (UV) radiation at the Earth’s surface has beneficial and adverse effects on human health (Juzeniene et al, 2011)
While the UV-B [280, 320] nm band is the major contributor to erythemal UV, interest is growing in the role of UV-A [320, 400] nm and UV [280, 400] nm on various diseases, such as viral infections (Norval, 2006), multiple sclerosis (Orton et al, 2011), Parkinson’s disease (Kravietz et al, 2017), eye diseases (Delcourt et al, 2014), skin cancer (Coste et al, 2015; Fortes et al, 2016) or thyroid cancer (Mesrine et al, 2017), among many others (Juzeniene et al, 2011; Norval and Halliday, 2011)
The results of the proposed method were compared to measurements of UV-A and UV-B irradiances at the surface for cloud-free conditions
Summary
Solar ultraviolet (UV) radiation at the Earth’s surface has beneficial and adverse effects on human health (Juzeniene et al, 2011). A comparison between 1200 measured UV spectra and estimates made with a previous version called uvspec – part of libRadtran – with only ozone and aerosol optical properties as inputs yielded very good performance for simulating the UV irradiance under cloud-free conditions (Mayer et al, 1997). The operational McClear model estimating the total irradiance in cloud-free conditions accurately reproduces the irradiance computed by libRadtran based on the Kato et al (1999) approach (Lefèvre et al, 2013). The McClear model uses several look up tables computed by libRadtran for selected values of inputs and provides the irradiance at each of the 32 spectral intervals Hereafter, these 32 spectral intervals are named Kato bands and abbreviated KB with the number in subscript. Five stations which are located at high latitudes were selected
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
