PUB - Publikationen an der Universität Bielefeld

This chapter describes a case study in reproducing results in the area of atmospheric chemistry. The specific result reproduced is described in the paper ‘BINARY: an optical freezing array for assessing temperature and time dependence of heterogeneous ice nucleation’ by Budke and Koop [1]. The study investigated the conditions under which ice nucleation occurs using Snomax®, a commercial ice inducer containing freeze-dried nonviable bacterial cells from Pseudomonas syringae, as a test substance for the investigation of heterogeneous ice nucleation processes. The ice inducing bacterial cell agents are known to be active at high temperature and are used in snow cannons. The study considered a temperature range between 0◦C and -12◦C. The main result was the finding that two classes of nucleations occur at a number ratio of about 1 to 1000 in the chemical samples, based on the difference of 3 orders of magnitude of the temperature plateau values. As a result of the Conquaire project, we reimplemented the original workflow relying on OriginPro in Python and could reproduce the central figure of the above mentioned paper by Budke and Koop using free and open software. This thus counts as a case of full analytical reproducibility. The data and scripts for the paper by Budke and Koop are available at https: //gitlab.ub.uni-bielefeld.de/conquaire/atmospheric_chemistry