An improved Freezing Ice Nucleation Detection Analyzer (FINDA) for droplet immersion freezing measurement
Abstract. Heterogeneous ice nucleation initiated by atmospheric ice-nucleating particles (INPs) is a key microphysical process for cloud formation. Detecting the ice nucleation ability (INA) and concentration of INPs is essential for improving global climate models. Droplet freezing techniques (DFTs) are among the widely used tools for measuring the immersion freezing of INPs, which is a predominant ice nucleation process in mixed-phase clouds. To enhance the efficiency and accuracy of DFTs, we developed a Freezing Ice Nucleation Detection Analyzer at Westlake University (FINDA-WLU) with an improved hardware setup, user-friendly software, precise droplet freezing detection, and rigorous temperature calibrations. The temperature uncertainty of FINDA-WLU is about ±0.60 °C, considering both vertical heat transfer efficiency and horizontal temperature heterogeneity. The system is tested with Milli-Q ultrapure water and reference materials like Arizona Test Dust and Snomax®, and the results are consistent with previous studies. We also use the FINDA-WLU to measure INPs in precipitation samples collected in China. Overall, FINDA-WLU proved to be a reliable and precise method for measuring INA and INP concentrations.
Authors
- Markus Hartmann (ORCID: https://orcid.org/0000-0001-9700-1701)
- Zhijun Wu (ORCID: https://orcid.org/0000-0002-7705-2373)
- Jie Gao (ORCID: https://orcid.org/0000-0002-6621-0604)
- Frank Stratmann (ORCID: https://orcid.org/0000-0003-1977-1158)
- Yunbo Chen (ORCID: https://orcid.org/0000-0002-5843-1386)
- Xiongying Zhang
- Kaiqi Wang (ORCID: https://orcid.org/0000-0001-6589-3194)
- Yaqiong Hu (ORCID: https://orcid.org/0000-0003-3710-7488)
- Xianda Gong (ORCID: https://orcid.org/0000-0001-7274-0639)
- Ping Tian (ORCID: https://orcid.org/0000-0002-8795-5605)
- Mengyu Huang (ORCID: https://orcid.org/0000-0001-5121-5499)
- Shu‐Ling Chen (ORCID: https://orcid.org/0000-0002-1513-4365)
- Heike Wex (ORCID: https://orcid.org/0000-0003-2129-9323)
- Ottmar Möhler (ORCID: https://orcid.org/0000-0002-7551-9814)
- Jie Chen (ORCID: https://orcid.org/0000-0001-5353-1110)
- Huiwen Xue (ORCID: https://orcid.org/0000-0002-1353-842X)
- Ruijie Li (ORCID: https://orcid.org/0000-0002-1895-9936)
- Bingbing Wang (ORCID: https://orcid.org/0000-0001-9639-8735)
- Xiaoyu Xu (ORCID: https://orcid.org/0000-0002-2021-1142)
- Xincheng Ma
- Kai Bi
- Yuhan Cheng (ORCID: https://orcid.org/0009-0004-3566-6563)
Institutions
- Karlsruhe Institute of Technology (DE)
- China Meteorological Administration (CN)
- Yunnan University (CN)
- Xiamen University (CN)
- Peking University (CN)
- Westlake University (CN)
- ETH Zurich (CH)
- Institute for Biomedical Engineering (CH)
- Leibniz Institute for Tropospheric Research (DE)
- State Key Joint Laboratory of Environment Simulation and Pollution Control (CN)
- Beijing Meteorological Bureau (CN)
- Zhejiang University (CN)
Publication Details
- Journal
- Atmospheric measurement techniques
- Published
- 2025-10-29
- DOI
- https://doi.org/10.5194/amt-18-5823-2025
- Primary Topic
- Atmospheric aerosols and clouds
- Type
- article
- Field-Weighted Citation Impact
- 0.00