Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

The present study aims at producing localized near-surface icing envelopes that contribute to optimal designs of near-surface structures under icing conditions. For this purpose, the 99th percentiles of liquid water content and wind speed that correspond to low-level supercooled clouds are used. Near-surface icing events and cloud microphysics are explored using North American Regional Reanalysis during winter months (D-J-F), over 32years. The investigation of the regional climatology of icing events involves 74 regional zones that cover Canada. For each zone, regional power loss of wind turbines under icing condition is estimated. The East and West coastal regions of the Hudson Bay demonstrate higher liquid cloud water of 0.4gm-3. The highest potential of wind is located in the West coast. The climatology of liquid water content around the Rocky Mountains manifests orographic condensation of the Pacific moisture transported toward the mountains. Within the range of temperatures [-15°C to 0°C], the near-surface results over Canada show that the monthly mean of wind speeds varies mostly between 4ms-1 and 10ms-1, and the mean supercooled cloud water content decreases linearly from 0.3gm-3 to 0.2gm-3, with decreasing temperature. The quantification of ice accumulation and the duration of icing events reveal that the West and the South of the Hudson Bay as well as the North of Manitoba and Ontario are exposed to extreme icing conditions, with a monthly accumulation that varies from 150mm to 225mm, and a monthly duration of icing events near 375h. Over the region encompassing the Gaspe Peninsula, St. Lawrence River and New Brunswick the higher limit of wind speed varies around 15ms-1. The cloud water upper limit of 0.45gm-3 occurs in December and January, and 0.3gm-3 in February. With decreasing temperature these upper limits reach 0.1gm-3 at -15°C. The highest wind energy is located in the Canadian East Coast regions. The Canadian arctic is characterized mostly by lower wind energy and larger power degradation under icing conditions. The average of wind turbine power loss during winter months (D-J-F) under icing conditions varies throughout Canada and reaches its maximum of about 15% over North-East of Manitoba, South of the Hudson Bay and the North coast of Ontario.