The characteristics of atmospheric ice nuclei measured at the top of Huangshan (the Yellow Mountains) in Southeast China using a newly built static vacuum water vapor diffusion chamber

Re-evaluating the Frankfurt isothermal static diffusion chamber for ice nucleation

“…A programmable electrostatic aerosol collector (PEAC7) has been developed for the automated sequential sampling of up to seven wafers. The PEAC7 is based on the design of the single wafer electrostatic aerosol collector as described in Klein et al (2010a, b) but adds a rotatable wafer tray that includes seven sampling slots. In Fig.…”

“…Experiments demonstrate that the process of ice identification and INP counting are sensitive to illumination, camera resolution and image contrast, and that the INP identification procedure used until 2012 introduced asystematic errors. Thus, FRIDGE data generated between 2008 and 2012 (data appear in the following publications: Bundke et al, 2008;Klein et al, 2010a, b;Bingemer et al, 2012;Niemand et al, 2012) have been identified to include erroneous measurements, resulting from the miscounting of liquid droplets as ice. Unfortunately, the full extent of the error is variable and depends upon the sampled aerosol, meaning that the entirety of data collected from the stated time period and reported in the cited publications must be re-evaluated.…”

“…The FRankfurt Ice nucleation Deposition freezinG Experiment (FRIDGE) is a system that pairs electrostatic precipitation of particles onto Si wafers in a collection unit with an isostatic diffusion chamber for the activation, growth and optical detection of ice on ice nucleating particles. The instrument and technique have been previously discussed (Bundke et al, 2008;Klein et al, 2010a); since the original development, new multiple-sampling (Sect. 2 and Schrod et al, 2013) and measurement chamber units (Jiang et al, 2015;Ardon-Dryer and Levin, 2014) have been built.…”

“…Since the FRIDGE instrument descriptions were first published by Bundke et al (2008) and Klein et al (2010a), there have been significant improvements in wafer analysis and the general understanding of results. Here we summarize recent experimental improvements made to FRIDGE, including a description of the automated PEAC7 (programmable electrostatic aerosol collector) sample collector, and report on errors that are contained in some of the previously published data from the FRIDGE method.…”

“…The existing FRIDGE analysis chambers are all based on the Frankfurt design but have been used in various operating modes (Klein et al, 2010a;Jiang et al, 2015;Ardon-Dryer and Levin, 2014). In particular the Tel Aviv group have employed the FRIDGE chamber to study immersion mode freezing using droplet assays (Ardon-Dryer et al, 2011;Ardon-Dryer and Levin, 2014).…”