Fire weather and lightning fires in a changing climate

荒地火灾在加拿大很常见，在过去十年中，平均每年发生8000起火灾，烧毁200万公顷土地。这一地区的大部分燃烧是由林分更新的高强度树冠火灾造成的。这些高强度火灾可能对社区产生重大影响；例如，2011年的奴隶湖大火和2003年的基洛纳大火造成了数亿美元的损失。**本研究将重点研究火灾天气、燃料湿度、闪电、火灾发生预测和气候变化三项相关研究。这些研究的目的是：1)开发一种利用气象站、雷达和闪电活动的混合方法，通过插值气象站观测、闪电活动水平（作为降水的代表）和降水雷达数据来估计整个景观的总风暴降水；2)开发并确定加拿大1-3天闪电预报模式的准确性；3)为加拿大开发1-3天雷电引起火灾的预测系统，然后将该预测系统与未来气候的一般环流模式一起用于估计21世纪剩余时间内的雷电和雷电引起火灾的发生。**火灾天气的最大挑战之一是确定气象站之间的天气状况，特别是降水的位置和数量。在火灾季节，大部分降水本质上是对流降水；阵雨和雷阵雨在空间和时间上变化很大。加拿大火灾天气指数系统中的燃料湿度由温度、降水、风速和相对湿度的观测决定。目前，我们只考虑降水，因为在计算整个地区的燃料湿度和火灾危险时，降水是最大的不确定性来源。我们将根据天气观测、雷达和闪电活动发展更完善的降水估计。**雷击引起的火灾发生预测模型已存在多年，大多数模型使用过去24小时内观测到的闪电活动和观测到的燃料湿度来估计火灾的发生。未来一两天的天气预报是可能的，但这些预报是基于观测到的闪电和天气预报中预测的燃料湿度而进行的，这些预测是针对持续燃烧的火灾（在地下闷烧，但在天气条件有利之前不会发展为火焰燃烧的火灾）。目前的方法有其局限性，因为它在火灾发生预测中没有考虑额外的闪电。将为加拿大发展三天闪电预报模式。**将为加拿大开发雷击火灾发生预测系统。利用该火灾发生预测系统和三天闪电预报模式以及环流模式数据，我们将对21世纪剩下的时间里的闪电和闪电引起的火灾进行模拟。**拟议的工作将导致火灾研究的进步，这将导致日常火灾管理活动的有意义的变化，这将有助于保护加拿大人和我们的社区。

Wildland fire is a common occurrence in Canada with 8000 fires burning 2 million hectares on average every year during the past decade. Most of this area burned results from stand-renewing high-intensity crown fires. These high intensity fires can have significant impact on communities; for example, the fires in Slave Lake in 2011 and Kelowna in 2003 sustained damages measured in 100s of millions of dollars.**This research will focus on three related studies examining fire weather, fuel moisture, lightning, fire occurrence prediction and climate change. The objectives of these studies are to: 1) develop a blended method using weather stations, radar and lightning activity to estimate total storm precipitation across the landscape through the interpolation of weather stations observations, the level of lightning activity ( as a proxy for precipitation) and precipitation radar data, 2) develop and determine the accuracy of a 1-3 day lightning forecast model for Canada, and 3) develop a 1-3 day lightning-caused fire occurrence prediction system for Canada and then use this prediction system along with General Circulations Models of future climate to estimate the lightning and the lightning - caused fire occurrence for the rest of the 21st century.**One of the largest challenges with the fire weather is determining the weather conditions between weather stations and in particular the location and amount of precipitation. During the fire season much of the precipitation is convective in nature; showers and thundershowers that are highly variable in space and time. Fuel moisture in the Canadian Fire Weather Index System is determined by observations of temperature, precipitation, wind speed and relative humidity. At this time, we are addressing only precipitation because it is the source of the largest uncertainty when calculating fuel moisture and fire danger across the landscape. We will develop improved precipitation estimates from the weather observations, radar and lightning activity.**Lightning-caused fire occurrence prediction models have been available for years and most models use observed lightning activity from the last 24 hours and observed fuel moisture to estimate fire starts. Forecasts for the next day or two are possible but these forecasts are for hold-over fires (fires that smoulder underground but don't progress to flaming combustion until the weather conditions are conducive) based on the observed lightning and forecasted fuel moisture derived from weather forecasts. This current approach is limited as it does not consider additional lightning in the fire occurrence prediction. A three day lightning forecast model will be developed for Canada.**A lightning-caused fire occurrence prediction system will be developed for Canada. Using this fire occurrence prediction system and the three day lightning forecast model along with General Circulation Model data we will model lightning and lighting-caused fire occurrence for the rest of the 21st century.**The proposed work will lead to advances in fire research that will result in meaningful changes in day-to-day fire management activities that will help protect Canadians and our communities.