The mechanisms involved in cloud formation affect the resulting cloud radiative properties. Therefore, accurate cloud formation models and related global warming models require freezing data for ammonium sulfate particles, a major constituent of upper tropospheric clouds. To determine possible explanations for disparate results among several laboratories, the experimental methods used in this study are closely examined. Experiments are performed to preclude artifacts, and experimental conditions are varied to develop a complete understanding of processes involved in particle freezing.
All experiments produce consistent results.
This result appears to partially explain the confusing and conflicting results coming from several laboratories employing different experimental methods to observe homogeneous ice nucleation in ammonium sulfate.