News 23.8.2023

Allergic to pollen? Scientists set the base to detect airborne pollen using lidars

Scientists characterized the optical properties of birch and pine pollen over the rural environment in Vehmasmäki, Kuopio, Finland. They used a synergy of three lidar instruments to retrieve the polarization value, a shape-relevant parameter, and the Ångström exponent, a size-relevant parameter, required for the determination of pollen presence.
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Pollen release in the Northern Hemisphere is well-documented, yet little is known about its vertical distribution and optical properties.

The three ground-based lidars, namely a multi-wavelength PollyXT lidar, a Vaisala CL61 ceilometer and a Halo Photonics StreamLine Pro Doppler lidar operate at different wavelengths allowing the optical characterization at four wavelengths (355, 532, 910 and 1565 nm). This multi-wavelength information can be used as the unique signature for each pollen type.

Together with pollen surface observations from a Hirst-type spore sampler and in-situ aerosol observations, the researchers found that the amount of pollen in the aerosol mixture is decisive to the observed lidar optical properties.

Furthermore, given the low concentration of pollen in the air, the inclusion of the longer wavelengths was found to be beneficial due to their sensitivity to trace large aerosol particles such that of pollen particles.

Accurate pollen representation is essential for minimizing allergy-related symptoms. Lidar observations can improve pollen forecasts serving as a validation tool or through the assimilation of the lidar observations in aerosol dispersion models of pollen.

Further information:

Maria Filioglou, Finnish Meteorological Institute,

Scientific article is available on Atmospheric Chemistry and Physics.

Reference: Filioglou, M., Leskinen, A., Vakkari, V., O'Connor, E., Tuononen, M., Tuominen, P., Laukkanen, S., Toiviainen, L., Saarto, A., Shang, X., Tiitta, P., and Komppula, M.: Spectral dependence of birch and pine pollen optical properties using a synergy of lidar instruments, Atmos. Chem. Phys., 23, 9009–9021,, 2023.

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