Autoren:	Weitzel, Maximilian Mitra, Subir K. Szakáll, Miklós Fugal, Jacob P. Borrmann, Stephan
Titel:	Application of holography and automated image processing for laboratory experiments on mass and fall speed of small cloud ice crystals
Online-Publikationsdatum:	28-Jan-2021
Erscheinungsdatum:	2020
Sprache des Dokuments:	Englisch
Zusammenfassung/Abstract:	An ice cloud chamber was developed at the Johannes Gutenberg University of Mainz for generating several thousand data points for mass and sedimentation velocity measurements of ice crystals with sizes less than 150 µm. Ice nucleation was initiated from a cloud of supercooled droplets by local cooling using a liquid nitrogen cold finger. Three-dimensional tracks of ice crystals falling through the slightly supersaturated environment were obtained from the reconstruction of sequential holographic images, automated detection of the crystals in the hologram reconstructions, and particle tracking. Through collection of the crystals and investigation under a microscope before and after melting, crystal mass was determined as a function of size. The experimentally obtained mass versus diameter (m(D)) power law relationship resulted in lower masses for small ice crystals than from commonly adopted parameterizations. Thus, they did not support the currently accepted extrapolation of relationships measured for larger crystal sizes. The relationship between Best (X) and Reynolds (Re) numbers for columnar crystals was found to be X=15.3 Re1.2, which is in general agreement with literature parameterizations.
DDC-Sachgruppe:	530 Physik 530 Physics 540 Chemie 540 Chemistry and allied sciences
Veröffentlichende Institution:	Johannes Gutenberg-Universität Mainz
Organisationseinheit:	FB 09 Chemie, Pharmazie u. Geowissensch.
Veröffentlichungsort:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-5608
Version:	Published version
Publikationstyp:	Zeitschriftenaufsatz
Nutzungsrechte:	CC BY
Informationen zu den Nutzungsrechten:	https://creativecommons.org/licenses/by/4.0/deed.en
Zeitschrift:	Atmospheric chemistry and physics 20 23
Seitenzahl oder Artikelnummer:	14889 14901
Verlag:	EGU
Verlagsort:	Katlenburg-Lindau
Erscheinungsdatum:	2020
ISSN:	1680-7324
URL der Originalveröffentlichung:	https://doi.org/10.5194/acp-20-14889-2020
DOI der Originalveröffentlichung:	10.5194/acp-20-14889-2020
Enthalten in den Sammlungen:	JGU-Publikationen