New operational perspective to identify aerosol in real-time with a pioneering algorithm (CONIOPOL) based on CL61 data

In recent years, there has been an increase in the intensity and frequency of smoke plume events over North America (sometimes reaching Europe) and dust plume events reaching Europe from Africa. As these can potentially affect surface air quality, environmental agencies are increasingly interested in being able to identify the nature of aerosol plumes, monitor it in real time and determine whether its interaction with the atmospheric boundary layer will impact surface air quality. The automatic LIDAR-ceilometer (ALC) primarily designed for cloud base height detection has greatly improved over the last years and now provides vertical profiles of backscatter from aerosols and clouds. Recently, a new type of ALC with a depolarization function (VAISALA CL61) is commercially available for distinguishing cloud phase (which is useful for weather forecasting) and also makes it possible to support the type identification of aerosols.

At the Royal Meteorological Institute of Belgium (RMI), we have been developing a new pioneering algorithm (CONIOPOL: CONIOlogy + POLarization) based only on CL61 measurements (backscatter and depolarization profiles) to provide in real-time automatic identification of cloud phase, precipitation type and aerosol type. CONIOPOL cannot provide an independent and unambiguous identification of the aerosol type because the CL61 operates with a single wavelength. Although, CONIOPOL is a very useful operational support allowing a quick identification in real time of the type of aerosols in combination with forecasts and backward trajectories models.

The effectiveness and robustness of CONIOPOL will be demonstrated in different ways, through case studies comparing its output with CAMS forecast and air quality measurements, through statistical analysis of CONIOPOL output and by a comparison analysis between CONIOPOL output and CAMS forecasts. In addition to its operational use, it is capable of assembling a climatology of cloud phase, precipitation type and aerosol type. Further, it can contribute to the validation of EarthCARE (ESA) space-borne products.