Fire weather and lightning fires in a changing climate

气候变化中的火灾天气和闪电火灾

• 批准号: RGPIN-2014-04204
• 负责人: Flannigan, Mike
• 金额: $ 1.97万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610893
• 关键词: Fire; weather; lightning; fires; changing

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.

荒地火灾在加拿大很常见，过去十年平均每年发生 8000 起火灾，烧毁面积达 200 万公顷。该地区大部分被烧毁的原因是森林更新的高强度树冠火灾。这些高强度火灾会对社区产生重大影响；例如，2011年奴隶湖和2003年基洛纳发生的火灾造成了数十亿美元的损失。 这项研究将重点关注火灾天气、燃料湿度、闪电、火灾发生预测和气候变化的三项相关研究。这些研究的目标是：1) 开发一种使用气象站、雷达和闪电活动的混合方法，通过气象站观测、闪电活动水平（作为降水的代理）和降水雷达数据的插值来估计整个地区的风暴降水总量，2) 开发并确定加拿大 1-3 天闪电预报模型的准确性，以及 3) 开发 1-3 天闪电引起的火灾发生 加拿大的预测系统，然后使用该预测系统以及未来气候的大气环流模型来估计 21 世纪剩余时间的闪电和闪电引起的火灾发生情况。 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是通过对温度、降水、风速和相对湿度的观测来确定的。目前，我们仅解决降水问题，因为在计算整个地区的燃料湿度和火灾危险时，降水是最大不确定性的来源。我们将根据天气观测、雷达和闪电活动改进降水估算。 闪电引起的火灾发生预测模型已经存在多年，大多数模型使用过去 24 小时观测到的闪电活动和观测到的燃料湿度来估计火灾发生。未来一两天的预测是可能的，但这些预测是针对滞留火灾（在地下阴燃但在天气条件有利之前不会发展为火焰燃烧的火灾）的，基于观测到的闪电和根据天气预报得出的预测燃料湿度。目前的方法有局限性，因为它在火灾发生预测中没有考虑额外的闪电。将为加拿大开发三天闪电预报模型。 将为加拿大开发闪电引起的火灾发生预测系统。使用该火灾发生预测系统和三天闪电预测模型以及大气环流模型数据，我们将对 21 世纪剩余时间的闪电和雷电引起的火灾发生进行建模。 拟议的工作将推动火灾研究的进步，从而使日常火灾管理活动发生有意义的变化，从而有助于保护加拿大人和我们的社区。