1.1 Using Ceilometer-Attenuated Backscatter Profiles in Meteorological Applications

Monday, 13 January 2020: 8:30 AM
203 (Boston Convention and Exhibition Center)
Minttu Tuononen, Vaisala Oyj, Helsinki, Finland; and R. Lehtinen

Ceilometer is a cost-effective lidar-based instrument typically used in aviation to detect cloud base heights. Ceilometers can also report the full attenuated backscatter profile, and the profile data can be used to obtain much more information than only cloud base heights. In this presentation, the focus is on the use of ceilometer attenuated backscatter profiles in different meteorological applications, potentially using large networks of ceilometers.

We present how to use ceilometer attenuated backscatter profile data to distinguish between liquid cloud layers, ice clouds, precipitation, and fog. Furthermore, we demonstrate the possibility of identifying elevated aerosol layers, such as volcanic ash and dust layers, and of obtaining the mixing layer height. In addition, in precipitation the melting layer is clearly visible when looking into the attenuated backscatter profiles. All these pieces of information can be used in various meteorological applications, from in-situ cloud observations to air quality studies and model validation. The value of ceilometer attenuated backscatter profile data has also been acknowledged by the research community, which is evident through the growing interest towards ground-based remote sensing. For example, in Europe there have been successful efforts to collect and harmonize the ceilometer attenuated backscatter data from hundreds of sites, and European-wide network, E-PROFILE, already exists. Therefore, the ceilometers can be effectively used as an input in numerical weather prediction models and to validate the models.

One concrete example of an important application is presented: the use of liquid layer identification in wind turbine icing applications. Especially in cold climates, the use of ceilometers in detecting potential icing conditions – precipitation and in-cloud icing in supercooled liquid clouds – is a promising new application for ceilometers.

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