Possible impacts of climate change on freezing rain in south-central Canada using downscaled future climate scenarios

Abstract

Abstract. Freezing rain is a major atmospheric hazard in mid-latitude nations of the globe. Among all Canadian hydrometeorological hazards, freezing rain is associated with the highest damage costs per event. Using synoptic weather typing to identify the occurrence of freezing rain events, this study estimates changes in future freezing rain events under future climate scenarios for south-central Canada. Synoptic weather typing consists of principal components analysis, an average linkage clustering procedure (i.e., a hierarchical agglomerative cluster method), and discriminant function analysis (a nonhierarchical method). Meteorological data used in the analysis included hourly surface observations from 15 selected weather stations and six atmospheric levels of six-hourly National Centers for Environmental Prediction (NCEP) upper-air reanalysis weather variables for the winter months (November-April) of 1958/59-2000/01. A statistical downscaling method was used to downscale four general circulation model (GCM) scenarios to the selected weather stations. Using downscaled scenarios, discriminant function analysis was used to project the occurrence of future weather types. The within-type frequency of future freezing rain events is assumed to be directly proportional to the change in frequency of future freezing rain-related weather typesThe results showed that with warming temperatures in a future climate, percentage increases in the occurrence of freezing rain events in the north of the study area are likely to be greater than those in the south. By the 2050s, freezing rain events for the three colder months (December-February) could increase by about 85% (95% confidence interval -CI: ±13%), 60% (95% CI: ±9%), and 40% (95% CI: ±6%) in northern Ontario, eastern Ontario (including Montreal, Quebec), and southern Ontario, respectively. The increase by the 2080s could be even greater: about 135% (95% CI: ±20%),Correspondence to: C. S. Cheng (shouquan.cheng@ec.gc.ca) 95% (95% CI: ±13%), and 45% (95% CI: ±9%). For the three warmer months (November, March, April), the percentage increases in future freezing rain events are projected to be much smaller with some areas showing either a decrease or little change in frequency of freezing rain. On average, northern Ontario could experience about 10% (95% CI: ±2%) and 20% (95% CI: ±4%) more freezing rain events by the 2050s and 2080s, respectively. However, future freezing rain events in southern Ontario could decrease about 10% (95% CI: ±3%) and 15% (95% CI: ±5%) by the 2050s and 2080s, respectively. In eastern Ontario (including Montreal, Quebec), the frequency of future freezing rain events is projected to remain the same as it is currently.

Possible Impacts of Climate Change on Freezing Rain Using Downscaled Future Climate Scenarios: Updated for Eastern Canada

“…It causes significant damage to overhead wires, communication towers, trees and agriculture due to ice accumulation; even small amounts of ice can cause dangerous driving and walking conditions (Regan, 1998;Dore, 2003;Changnon, 2004;Cheng et al, 2007;Houston and Changnon, 2007). Among all Canadian hydrometeorological disasters, freezing rain is associated with the most costly damage sustained per event (Dore, 2003).…”

A method to estimate freezing rain climatology from ERA-Interim reanalysis over Europe

“…Bernstein and Le Bot, 2009;Le Bot and Lassegues, 2004). More comprehensive studies have been undertaken on ice storm and FZRA climatologies over North America, including studies for various regions (Cortinas, 2000;Changnon, 2003;Cortinas et al, 2004), impacts of ice storms on different sectors (Proulx and Greene, 2001), and changes in FZRA climatology (Cheng et al, 2007(Cheng et al, , 2011Lambert and Hansen, 2011;Klima and Morgan, 2015) as well as on various wintertime precipitation types (Stewart et al, 2015) and impacts and details of FZRA storms and related synoptics (Hosek et al, 2011;Call, 2010;Roberts et al, 2008).…”

Evaluating the Ability of CRCM5 to Simulate Mixed Precipitation

“…Some studies have already estimated the modification of ZR behaviour with climate change using global climate and/or statistical models. They suggest that in the future, more ZR events may occur in higher latitudes and fewer in lower latitudes (e.g., Cheng, Auld, Li, Klaasen, & Li, 2007;Cheng et al, 2004;Klima & Morgan, 2015;Lambert & Hansen, 2011). Although the coarse resolution of global models may be sufficient to simulate large-scale geographical variations of mixed precipitation, it is inadequate for representing the regional details of anticipated future changes.…”