Tiitta, P., Leskinen, A., Kaikkonen, V. A., Molkoselkä, E. O., Mäkynen, A. J., Joutsensaari, J., Calderon, S., Romakkaniemi, S., and Komppula, M.: Intercomparison of holographic imaging and single-particle forward light scattering in situ measurements of liquid clouds in changing atmospheric conditions, Atmos. Meas. Tech., 15, 2993–3009, https://doi.org/10.5194/amt-15-2993-2022, 2022.
Intercomparison of holographic imaging and single-particle forward light scattering in situ measurements of liquid clouds in changing atmospheric conditions
|Author:||Tiitta, Petri1; Leskinen, Ari1,2; Kaikkonen, Ville A.3;|
1Finnish Meteorological Institute, Atmospheric Research Centre of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland
2Department of Applied Physics, Univ. of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland
3Unit of Measurement Technology, University of Oulu, Technology Park P.O. Box 127, 87400 Kajaani, Finland
4Optoelectronics and Measurement Techniques Unit, University of Oulu, P.O. Box 4500, 90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 4.3 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2023022128034
|Publish Date:|| 2023-02-21
Upon a new measurement technique, it is possible to sharpen the determination of microphysical properties of cloud droplets using high resolving power imaging. The shape, size, and position of each particle inside a well-defined, three-dimensional sample volume can be measured with holographic methods without assumptions of particle properties. In situ cloud measurements were carried out at the Puijo station in Kuopio, Finland, focusing on intercomparisons between cloud droplet analyzers over 2 months in September–November 2020. The novel holographic imaging instrument (ICEMET) was adapted to measure microphysical properties of liquid clouds, and these values were compared with parallel measurements of a cloud droplet spectrometer (FM-120) and particle measurements using a twin-inlet system. When the intercomparison was carried out during isoaxial sampling, our results showed good agreement in terms of variability between the instruments, with the averaged ratios between ICEMET and FM-120 being 0.6 ± 0.2, 1.0 ± 0.5, and 1.2 ± 0.2 for the total number concentration (Nd) of droplets, liquid water content (LWC), and median volume diameter (MVD), respectively. This agreement during isoaxial sampling was also confirmed by mutual correlation and Pearson correlation coefficients. The ICEMET-observed LWC was more reliable than FM-120 (without a swivel-head mount), which was verified by comparing the estimated LWC to measured values, whereas the twin-inlet DMPS system and FM-120 observations of Nd showed good agreement both in variability and amplitude. Field data revealed that ICEMET can detect small cloud droplets down to 5 µm via geometric magnification.
Atmospheric measurement techniques
|Pages:||2993 - 3009|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
This research has been supported by the Academy of Finland (grant no. 309127), the Horizon 2020 (FORCeS (grant no. 821205)), the European Regional Development Fund (ERDF) under European Territorial Cooperation (ETC) program Interreg V A Nord (grant no. NYPS 20202472), and in part by the Regional Council of Lapland (grant no. 126/00.01.05.24.02/2019).
© Author(s) 2022. This work is distributed under the Creative Commons Attribution 4.0 License.