Quantifying riming from airborne data during the HALO-(AC)³ campaign

Abstract 3 aircraft campaign, where two aircraft collected radar and in situ measurements that were closely spatially and temporally collocated over the Fram Strait west of Svalbard in spring 2022. The first method is based on an inverse optimal estimation algorithm for the retrieval of the normalized rime mass from a closure between cloud radar and in situ measurements during these collocated flight segments (combined method). The second method relies on in situ observations only, relating the normalized rime mass to optical particle shape measurements (in situ method). We find good agreement between both methods during collocated flight segments with median normalized rime masses of 0.024 and 0.021 (mean values of 0.035 and 0.033) for the combined and in situ method, respectively. Assuming that particles with a normalized rime mass smaller than 0.01 are unrimed, we obtain average rimed fractions of 88 % and 87 % over all collocated flight segments. Although in situ measurement volumes are in the range of a few cubic centimeters and are therefore much smaller than the radar volume (about 45 m footprint diameter at an altitude of 500 m above ground, with a vertical resolution of 5 m), we assume they are representative of the radar volume. When this assumption is not met due to less homogeneous conditions, discrepancies between the two methods result. We show the performance of the methods in a case study of a collocated segment of cold-air outbreak conditions and compare normalized rime mass results with meteorological and cloud parameters. We find that higher normalized rime masses correlate with streaks of higher radar reflectivity. The methods presented improve our ability to quantify riming from aircraft observations.

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch

Verweise und Beziehungen

• Erschienen in: Quantifying riming from airborne data during the HALO-(AC)³ campaign ; volume:17 ; number:5 ; year:2024 ; pages:1475-1495 ; extent:21 ; Atmospheric measurement techniques ; 17, Heft 5 (2024), 1475-1495 (gesamt 21)

Beteiligte, Orts- und Zeitangaben

• Urheber: Maherndl, Nina ; Moser, Manuel ; Lucke, Johannes ; Mech, Mario ; Risse, Nils ; Schirmacher, Imke ; Maahn, Maximilian

Weitere Informationen

• DOI: 10.5194/amt-17-1475-2024
• URN: urn:nbn:de:101:1-2024031403182375067051
• Rechteinformation: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 14.08.2025, 10:50 MESZ