Sensitivity of Precipitation Formation to Secondary Ice Production in Alpine Clouds

A sensitivity model study simulates secondary ice production processes in winter orographic clouds over the Eastern Swiss Alps. The research, led by Zane Dedekind at ETH Zurich, models a cold front passage at Gotschnagrat peak on 7 March 2019 using the COSMO model at 1 km resolution. Collisional breakup simulations caused a 1 to 3 order of magnitude increase in ice crystal number concentration compared to control runs, improving agreement with field campaign measurements.

Use Cases

• Calibrating numerical weather prediction models based on simulated ice crystal number concentrations.
• Studying the impact of secondary ice production mechanisms like rime splintering and collisional breakup on precipitation.
• Validating model outputs against in-situ measurements from field campaigns such as RACLETS.
• Analyzing how enhanced ice formation influences precipitation amount, location, and intensity.

Strengths

• Focuses on a specific, high-resolution (1 km) case study of a cold front passage in the Swiss Alps.
• Compares multiple secondary ice production processes: rime splintering, droplet shattering, and ice-ice collisional breakup.
• Model outputs are compared to in-situ ICNC measurements from a gondola near the surface.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and file formats are unknown, which may limit suitability assessment.

Provenance

Source

Zane Dedekind, ETH Zurich

Collection Method

Numerical simulation using the COSMO model as part of the RACLETS field campaign.

Time Range

7 March 2019

Geography

Gotschnagrat peak (2281 m a.s.l.) in the Eastern Swiss Alps, Davos region, Switzerland