Canadian Fire Weather System - WRF/NOA

The <strong>Canadian FWI System </strong>(Van Wagner, 1987) is a sub-system of the Canadian Fire Danger Rating System (Stocks et al., 1989), comprised of <strong>five components</strong> that consider the effects of fuel moisture and wind on fire behavior. The first three components, called <strong>fuel moisture codes</strong>, are numeric ratings of <strong>(1) </strong>the moisture content of surface litter and other fine fuels (fine fuel moisture code; <strong>FFMC</strong>), <strong>(2)</strong> the average moisture content of loosely compacted organic material (duff moisture code; <strong>DMC</strong>), and <strong>(3)</strong> the average moisture content of deep layers of organic material (drought code; <strong>DC</strong>). The remaining two components are related to <strong>fire behavior and spread</strong>: <strong>(1)</strong> the initial spread index (<strong>ISI</strong>), which represents the rate of spread, and <strong>(2) </strong>the build-up index (<strong>BUI</strong>), which represents the potential fuel availability. The above five parameters are finally combined for computing the <strong>fire weather index</strong> (hereafter referred to as the <strong>FWI</strong>), which represents the intensity of a spreading fire per unit length of fire front and is used as an indicator of fire danger. Computation of the Canadian Fire Weather System components was carried out using <strong>12 UTC meteorological data</strong> extracted from <strong>high-resolution (~12 km) WRF simulations</strong>, focussing on the <strong>Euro-Mediterranean region</strong>. These data include the 24 h accumulated precipitation (mm), 2 m air temperature (^oC) and relative humidity (%), and 10 m wind speed (km h^-1). It should be noted that normally, FWI is computed using meteorological data at 12 local time. The use of the 12 UTC data in our study is dictated by the fact that the Euro-Mediterranean encompasses different time zones (e.g. Bedia et al., 2012, 2018; Herrera et al., 2013). Details: File format: netcdf4 Coordinate system: World Geodetic System 1984 (also known as WGS 1984, EPSG:4326) Longitude range: [-9.91, +36.4] Latitude range: [+32.1, +48.93] Temporal resolution: 1 day (at 12 UTC) Spatial resolution: 0.12 degrees (~12 Km) Spatial coverage: Euro-Mediterranean Time span: May 1 to September 30, for the years 1987-2016 Stream: Regional climate simulations (driven by the WRF model)**加拿大火天气指数系统（Canadian FWI System）**（Van Wagner, 1987）是加拿大火危险评级系统（Canadian Fire Danger Rating System，Stocks等, 1989）的子系统，由**五个组分**构成，可综合考量燃料湿度与风速对火灾行为的影响。其中前三个组分被称为**燃料湿度编码**，分别为：(1) 地表枯落物及其他精细燃料的含水量数值评级（精细燃料湿度编码，Fine Fuel Moisture Code，FFMC）；(2) 松散压实有机物质的平均含水量数值评级（腐殖质湿度编码，Duff Moisture Code，DMC）；(3) 深层有机物质的平均含水量数值评级（干旱编码，Drought Code，DC）。剩余两个组分则与**火灾行为与蔓延**相关：(1) 初始蔓延指数（Initial Spread Index，ISI），用于表征火势蔓延速率；(2) 蓄积指数（Build-up Index，BUI），用于表征潜在燃料可获得性。上述五个参数最终将被整合，用于计算**火天气指数（Fire Weather Index，以下简称FWI）**——该指数可表征单位火前线长度下蔓延火灾的强度，作为火灾危险程度的指示指标。 本研究中，加拿大火天气系统组分的计算采用了从**高分辨率（约12 km）WRF模拟**数据中提取的**12时协调世界时（UTC）气象数据**，研究区域聚焦于**欧洲-地中海区域（Euro-Mediterranean region）**。此类数据包含24小时累积降水量（单位：毫米）、2米高度气温（单位：摄氏度）、相对湿度（单位：%）以及10米高度风速（单位：千米/小时）。需说明的是，常规FWI计算采用当地时间12时的气象数据，而本研究选用12时协调世界时数据，系因欧洲-地中海区域涵盖多个时区（如Bedia等, 2012, 2018; Herrera等, 2013）。 数据集详情： - 文件格式：netCDF4 - 坐标系：1984世界大地测量系统（又称WGS 1984，EPSG:4326） - 经度范围：[-9.91, +36.4] - 纬度范围：[+32.1, +48.93] - 时间分辨率：1天（数据对应12时协调世界时） - 空间分辨率：0.12度（约12公里） - 空间覆盖范围：欧洲-地中海区域 - 时间跨度：1987年至2016年每年的5月1日至9月30日 - 数据源流：由WRF模式驱动的区域气候模拟