Prediction of In-Cloud Icing Conditions at Ground Level Using the WRF Model

Bjørn Egil Kringlebotn Nygaard (Corresponding Author), Jón Egill Kristjánsson, Lasse Makkonen

Research output: Contribution to journalArticleScientificpeer-review

30 Citations (Scopus)

Abstract

In-cloud icing on aircraft and ground structures can be observed every winter in many countries. In extreme cases ice can cause accidents and damage to infrastructure such as power transmission lines, telecommunication towers, wind turbines, ski lifts, and so on. This study investigates the potential for predicting episodes of in-cloud icing at ground level using a state-of-the-art numerical weather prediction model. The Weather Research and Forecasting (WRF) model is applied, with attention paid to the model’s skill to explicitly predict the amount of supercooled cloud liquid water content (SLWC) at the ground level at different horizontal resolutions and with different cloud microphysics schemes. The paper also discusses how well the median volume droplet diameter (MVD) can be diagnosed from the model output. A unique dataset of direct measurements of SLWC and MVD at ground level on a hilltop in northern Finland is used for validation. A mean absolute error of predicted SLWC as low as 0.08 g m−3 is obtained when the highest model resolution is applied (grid spacing equal to 0.333 km), together with the Thompson microphysics scheme. The quality of the SLWC predictions decreases dramatically with decreasing model resolution, and a systematic difference in predictive skill is found between the cloud microphysics schemes applied. A comparison between measured and predicted MVD shows that when prescribing the droplet concentration equal to 250 cm−3 the model predicts MVDs ranging from 12 to 20 μm, which corresponds well to the measured range. However, the variation from case to case is not captured by the current cloud microphysics schemes.
Original languageEnglish
Pages (from-to)2445-2459
Number of pages15
JournalJournal of Applied Meteorology and Climatology
Volume50
Issue number12
DOIs
Publication statusPublished - 2011
MoE publication typeA1 Journal article-refereed

Fingerprint

weather
cloud microphysics
droplet
prediction
water content
liquid
wind turbine
telecommunication
accident
aircraft
spacing
infrastructure
ice
damage
winter

Keywords

  • cloud droplets
  • cloud water phase
  • icing
  • cloud parameterization
  • orographic effects

Cite this

Nygaard, Bjørn Egil Kringlebotn ; Kristjánsson, Jón Egill ; Makkonen, Lasse. / Prediction of In-Cloud Icing Conditions at Ground Level Using the WRF Model. In: Journal of Applied Meteorology and Climatology. 2011 ; Vol. 50, No. 12. pp. 2445-2459.
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Prediction of In-Cloud Icing Conditions at Ground Level Using the WRF Model. / Nygaard, Bjørn Egil Kringlebotn (Corresponding Author); Kristjánsson, Jón Egill; Makkonen, Lasse.

In: Journal of Applied Meteorology and Climatology, Vol. 50, No. 12, 2011, p. 2445-2459.

Research output: Contribution to journalArticleScientificpeer-review

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