Atmospheric visibility (turbidity/fog) is driven by the interaction of moisture with solid or liquid particles that are suspended in the air (aerosols). Despite the importance of this effect, up-to-date the hygroscopic growth of aerosols is not at all, or not well represented in numerical weather prediction (NWP) models.
The reason is simply given by the fact that climate and NWP models do not yet capture the required thermodynamic processes, because of their immense complexity. However, during the last years we have developed parameterizations that can circumvent this complexity without loss of crucial accuracy.
Our research focused on the hygroscopic growth of atmospheric aerosols, the associated multiphase chemistry, the important aerosol-haze-fog-cloud-radiation interactions (visibility/turbidity/light dimming), and the air pollution and climate-change feedbacks due to aerosol water uptake. The research has led to the development of computationally efficient thermodynamical algorithms that enable an unique analytical computation of the water activity based on the actual cation-anion composition, and the crucial aerosol water uptake in numerical forecast models. As a result more reliable visibility calculations can be provided for various applications.
Areas of application
Visibility has a substantial impact on security as well as on the profitability of businesses, ranging from
- renewable energy production
- aviation industry
- military services
- automotive industry
- pharmaceutical industry
- environmental protection
For example, concentrated solar power stations (CSP) heavily rely on a precise forecasts of the energy production 24h in advance (day ahead market) as power grid managers need to ensure its stability. Any deviation in the forecasts result in additional cost for either the storage of the over-production or the purchase of additional peak power in case of lower than expected energy production. By increasing the accuracy of the forecasts of irradiation, taking into account water and dust as well as cloud coupling, CSPs can substantially enhance their profitability.