Drone-Based Investigation of Biological INPs in the Atmosphere

In the last decades, it has been discovered that many biological ice nucleating particles (INPs) induce ice formation at highest subzero temperatures. Even though several plants, such as birch trees, conifer trees [1] or winter rye [2] are identified as potential sources of biological INPs, little is known about the transport of INPs from the biosphere to the atmosphere. It is unclear if just pollen grains release INPs, or if the plant itself can act as a donor, when rainfall washes off surface extracts. To fill this gap of knowledge, we use drones and sample aerosols in the vicinity of plants to monitor transport processes at several conditions.

The Drone-based Aerosol Particle Sampling Impinger/Impactor (DAPSI) is a new developed system that can be attached to small-scale drones such as the DJI Phantom 4 model. The impinger unit provides a sampling method for INPs in water. Ice nucleation activity of obtained aqueous solutions can then be analyzed with a cryo-microscopy setup. Further, an onboard computer monitors temperature, relative humidity, pressure and particle concentrations in the approached areas. The second system includes an impactor that samples aerosol particles in different size ranges and provides templates for microscopic analytics. Several test runs were performed using an aerosol chamber to validate the system. First field studies confirm that DAPSI can be used to detect pollen grains, INPs and other biological aerosol particles in the size range between 0.25 µm and 2.5 µm.

References

[1] Pummer, B. G., Bauer, H., Bernardi, J., Bleicher, S., and Grothe, H.: Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen, Atmos. Chem. Phys., (12), 2541-2550, DOI: 10.5194/acp-12-2541-2012, 2012.

[2] Brush, R. A., Griffith, M., Mlynarz, A.: Characterization and Quantification of Intrinsic Ice Nucleators in Winter Rye (Secale cereale) Leaves, Plant Physiology, 104 (2) 725-735; DOI: 10.1104/pp.104.2.725, 1994.