Co-located in-situ and remote sensing observations of freshly formed ice crystals generated by targeted glaciogenic cloud seeding
| Autor: | Fuchs, C., Ramelli, F., Miller, A., Ohneiser, K., Omanovic, N., Rösch, M., Seifert, P., Spirig, R., Zhang, H., Lohmann, U., Henneberger, J. |
|---|---|
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-2839 |
| Popis: | The formation and growth of ice in clouds are essential for precipitation formation. Despite advances in our understanding of ice phase processes arising from laboratory and modeling studies, a major gap exists in representative in-situ field observations. CLOUDLAB aims to fill this gap by performing targeted glaciogenic cloud seeding experiments (using silver iodide injections) in supercooled, predominantly liquid stratus clouds over the Swiss Plateau to induce ice crystal formation and subsequent growth processes. Downwind of the seeding location, the freshly generated ice crystals are observed using two scanning cloud radars and a tethered balloon system equipped with an optical particle counter and holographic imager. The holographic imager captures phase-resolved information about the number, size, and spatial distributions of hydrometeors with high spatio-temporal resolution (>6 µm, 40 Hz).We present in-situ and remote sensing data observed during a series of cloud seeding experiments. The ice crystal and aerosol number concentrations increased by several orders of magnitudes during the passage of the seeding plume. Simultaneously at the same location, the radar reflectivity increased by 10 to 20 dB compared to the unseeded background cloud. The observed ice crystals formed three to fifteen minutes before the detection and grew to a diameter of around 100-200 µm. We will also assess how the seeding influences the liquid phase (e.g. liquid water content, cloud droplet size) and answer the question: Does the seeding produce fully glaciated patches? This dataset provides unique insights into early-stage ice processes and broadens our understanding of precipitation formation. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|