We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Secondary Ice Production Improves Simulations of Freezing Rain.
- Authors
Cholette, Mélissa; Milbrandt, Jason A.; Morrison, Hugh; Kirk, Sabrina; Lalonde, Louis‐Émile
- Abstract
Weather forecasts and climate projections of precipitation phase and type in winter storms are challenging due to the complicated underlying microphysical and dynamical processes. In the Canadian numerical weather prediction model, explicit freezing rain (FR) at the surface is often overestimated during the winter season for situations in which snow is observed. For a case study simulated using this model with the Predicted Particle Properties (P3) microphysics scheme, the secondary ice production (SIP) process has a major impact on the surface precipitation type. Parameterized SIP substantially reduces FR due to increased collection of supercooled drops with ice particles formed by rime splintering. Hindcast simulations of 40 winter cases show that these results are systematic, and the decreased frequency of FR leads to improved forecast skill relative to observations. Thus, accounting for SIP in the model is critical for accurately simulating precipitation types. Plain Language Summary: Several types of winter precipitation, including snow, freezing rain (FR) and ice pellets (IP), are associated with hazards such as injuries from people falling, disruption of electrical supply, and breakdown of transportation networks due to the accumulation of ice on surfaces. Forecasts of precipitation type using weather prediction models, as well as projections for a warmer climate, are challenging because of the complicated physical processes involved. In this article, it is shown that the component of the numerical model that is used to represent clouds and precipitation in the Canadian high‐resolution weather forecast system overestimates FR at the expense of snow. This problem is mitigated when the additional process of secondary ice production (here, the generation of new ice particles from collisions of existing ice and supercooled drops) is included in the model. The presence of numerous small ice particles formed by this process decreases the amount of FR and improves forecast skill scores for 40 historic winter cases. Thus, accounting for this process in weather and climate models is important for accurately simulating FR, IP and snow. Key Points: Secondary ice production (SIP) substantially impacts precipitation phase and type in winter stormsInclusion of SIP reduces excessive freezing rain (FR) in numerical simulationsForecast metrics for FR in 40 winter cases are improved when SIP is included in a weather model
- Subjects
RAINFALL; NUMERICAL weather forecasting; ATMOSPHERIC models; WEATHER forecasting; PRECIPITATION forecasting; GLOBAL warming; WINTER storms
- Publication
Geophysical Research Letters, 2024, Vol 51, Issue 8, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2024GL108490