The Air Quality — Clear-Sky UV Index indicator shows the daily mean UV index calculated under clear-sky conditions, i.e. without cloud cover. It represents the theoretical maximum UV radiation that would reach the surface in the absence of clouds, considering only attenuation from stratospheric ozone and aerosols.
Comparing the UV Index (which includes cloud effects) with the Clear-Sky UV Index allows quantifying the protective effect of cloud cover. A UV/UV_clear_sky ratio close to 1 indicates predominantly clear skies; significantly lower values indicate strong cloud attenuation. This information is useful for estimating potential UV stress on vegetation and organisms under reduced cloud cover scenarios predicted by climate models.
Data come from the Open-Meteo Air Quality API (CAMS model). The variable used is uv_index_clear_sky (UV index under clear-sky conditions). For each day, the average of hourly values is calculated.
| Code | Name | Provider | Type | Coverage | Availability |
|---|---|---|---|---|---|
WRD_OPNAQ_99 | Open-Meteo Air Quality API | Open-Meteo / CAMS | db | Global (Europe: 11 km) | From 2013 to present |
Average daily UV index in clear sky conditions (without clouds). Open-Meteo variable: uv_index_clear_sky. Daily average of hourly values. Source: Open-Meteo Air Quality API (CAMS). Unit: dimensionless (scale 0-11+).