Remote sensing observations provide novel information on atmospheric aerosols
Remote sensing techniques provide a powerful tool for the observation of aerosol particles and clouds. The techniques were used in doctoral dissertation to investigate aerosols in the Arctic as well as properties of pollen and dust.
Lidars along with cloud radars are the two fundamental instruments in atmospheric research for the profiling of the atmosphere. To link aerosol properties and cloud formation, Maria Filioglou used a lidar-radar synergy in her doctoral thesis.
Low level mixed phase clouds are very common in the Arctic. The research shows that the amount of aerosols correlates with the occurrence of the cloud phase. Mixed-phase clouds were more abundant under the higher aerosol loading, supporting the extended lifetime of these clouds in the Arctic.
Moreover, depending on the aerosol load, the temperature at which a cloud completely glaciated varied by up to 6–10 °C, regardless the type of the aerosol. In comparison, the different aerosol types resulted to less than 4 °C discrepancies in the glaciation temperature. Thus, moderate association was found with varying the aerosol type as opposed to aerosol load.
Atmospheric aerosols are vastly heterogeneous in size, type and concentrations, and they also vary in both time and space. Currently, their role in cloud formation compiles one of the greatest sources of uncertainty in radiative forcing calculations and projections of future climate. Information about the interaction of aerosols and clouds helps to develop more precise climate projections.
Lidar setup can be used to classify pollen
The properties of pollen and Arabian dust are currently poorly known. Therefore, their effect on clouds and their potential to human health, including allergies, is not accurately represented in air quality and climate models.
The research shows that different pollen types can be classified with a lidar setup. The properties of Arabian dust differ from dust particles originating from the Saharan region. These differences should be considered in lidar-related applications.
Public examination can be followed online on 17 June
The doctoral dissertation of MSc Maria Filioglou, entitled Atmospheric profiling using the lidar technique will be examined at the Faculty of Science and Forestry 17 June (online).
The opponent in the public examination will be Manager, PhD Franco Marenco, Met Office, Satellite Imagery Applications Group (SIAG), UK, and the custos will be Head of Group, Docent Mika Komppula, Finnish Meteorological Institute.
The public examination will be held in English.
Follow the public examination online.
Further information:
Maria Filioglou, Finnish Meteorological Institute, tel. +358 50 463 9930, maria.filioglou@fmi.fi
Electronical version of the thesis is available on Helda.