Action period: 29/10/2019 - 28/10/2023

The atmospheric boundary layer (ABL) is the layer closest to the Earth's surface within which most human activities take place. The vertical profile of atmospheric thermodynamic parameters in the ABL impacts weather, air quality, and climate. Surface sensor networks and satellite observations do not provide sufficient information on the high temporal variability and strong vertical gradients experienced in the ABL. Thus, despite its importance, ABL remains the single most important under-sampled part of the atmosphere. This observational gap currently hampers our ability to improve weather forecasts, air quality prediction, and climate model parameterization. However, this gap is mainly due to the lack of S&T networking and coordination. In fact, state-of-the-art ground-based remote sensing instruments able to provide ABL profiles (such as temperature, humidity, wind, aerosol, cloud) are currently deployed at numerous sites in Europe, but the harmonization of data and procedures is missing, limiting the effective use and societal benefits of the existing ABL profiling data. This Action aims to fill this gap, bridging user needs and the S&T expertise residing in industry and academia. This will be achieved through:

• Capacity building of instrument operators to improve the use of state-of-the-art ABL profiling instruments
• Fostering coordination between operational agencies and academia to tailor measurement networks for well identified applications
• Enhancing pan-European research coordination to develop new products and tools for data assimilation and long time series reanalysis
• Identifying knowledge brokers enabling rapid exchange between academia, operational agencies, industry and end-users to ensure full exploitation for societal benefit.

Our team is mostly involved with the development of new and improved ABL products from the synergy of ABL profiling instruments. More specifically, Q. Laffineur is a member of the Management Committee.

The Action's homepage can be found here and more information is also available from the Action's webpage on the COST website.