Integrated Science Teaching in Atmospheric Ice Nucleation Research: Immersion Freezing Experiments

This paper introduces hands-on curricular modules integrated
with
research in atmospheric ice nucleation, which is an important phenomenon
potentially influencing global climate change. The primary goal of
this work is to promote meaningful laboratory exercises to enhance
the competence of students in the fields of science, technology, engineering,
and math (STEM) by applying an appropriate methodology to laboratory
ice nucleation measurements. To achieve this goal, three laboratory
modules were developed with 18 STEM interns and tested by 28 students
in a classroom setting. Students were trained to experimentally simulate
atmospheric ice nucleation and cloud droplet freezing. For practical
training, this work utilized a simple freezing assay device called
the West Texas Cryogenic Refrigerator Applied to Freezing Test (WT-CRAFT)
system. More specifically, students were provided with hands-on lessons
to calibrate WT-CRAFT with deionized water and apply analytical techniques
to understand the physicochemical properties of bulk water and droplet
freezing. All procedures to implement the developed modules were typewritten
during this process, and shareable read-ahead exploration materials
were developed and compiled as a curricular product. Additionally,
students conducted complementary analyses to identify possible catalysts
of heterogeneous freezing in the water. The water analyses included:
pH, conductivity, surface tension, and electron microscopy–energy-dispersive
X-ray spectroscopy. During the data and image analysis process, students
learned how to analyze droplet freezing spectra as a function of temperature,
screen and interpret the data, perform uncertainty analyses, and estimate
ice nucleation efficiency using computer programs. Based on the formal
program assessment of learning outcomes and direct (yet deidentified)
student feedback, we broadly achieved our goals to (1) improve their
problem-solving skills by combining multidisciplinary science and
math skills and (2) disseminate data and results with variability
and uncertainty. The developed modules can be applied at any institute
to advance undergraduate and graduate curricula in environmental science.