ACI-UV · Aerosol and Cloud Influence on global surface UV irradiance retrieved from satellite sensors

Aerosol and Cloud Influence on global surface UV irradiance retrieved from satellite sensors

Ultraviolet (UV) solar radiation has a broad range of effects concerning life on Earth. It influences not only human beings, but also plants and animals. Furthermore, it causes degradation of materials and functions as a driver of atmospheric chemistry. In order to study the UV related effects and their implications thoroughly; accurate information is needed on UV radiation intensities over the globe. The main overall scientific goal of this project is to search for improvements in estimating surface UV from satellite measurements and thus to decrease the uncertainty related to the globally available surface UV data, which is of importance and interest for a wide discipline of UV related studies. Since the network of ground-based UV measurements will inevitably remain sparse, satellitebased UV methods are needed to better document the geospatial distribution of the surface UV irradiance. Although the development of the algorithms to estimate the surface UV from satellite measurements has been on-going since the early 1990s, these algorithms still struggle with the same sources of uncertainty as ten years ago, namely the representation of aerosols and clouds in UV. Any possible improvements in the accuracy of the current global UV monitoring by satellite data would therefore be valuable for many purposes, e.g. for UV impact studies, estimates of longterm UV changes, scenarios of future ozone recovery and climatology. Moreover, there are additional products that would have importance, such as the actinic flux, critical input for UV driven photochemistry, that are not operationally available and only little has been done so far in order to assess the feasibility to derive them using satellite measurements. In all these aspects, the quality of satellite based UV measurements is of critical importance. The main overall scientific goal of this project is to search for improvements in estimating surface UV from satellite measurements and thus to decrease the uncertainty related to the globally available surface UV data, which is of importance and interest for a wide discipline of UV related studies. The specific goals of the project are: - To evaluate the improvement of the satellite-based surface UV irradiance estimates that are achievable with the synergistic use of satellite aerosol and cloud related data. - To assess the improvement of the satellite-based UV estimates that is achievable with the use of aerosol climatology. - To evaluate the effect of different factors affecting long term time series of solar UV irradiance. - To propose algorithms in order to calculate and evaluate photolysis frequencies of O1D and NO2 in a global scale using satellite products.

Data: CORDIS, © European Union