Global Fire Weather Indices - DMC using default DC start-up

This dataset was developed by Natural Resources Canada using the European Centre for Medium-range Weather Forecasts (ECMWF) ERA5-HRS Reanalysis product (C3S, 2017) as inputs to the Canadian Forest Fire Danger Rating System R Package (Wang et al. 2017). The dataset provides gridded values of the Canadian Fire Weather Index (FWI) System indices of fuel moisture and fire behaviour, including the Fine Fuel Moisture Code (FFMC), Duff Moisture Code (DMC), Drought Code (DC), Initial Spread Index (ISI), Build-Up Index (BUI), Fire Weather Index (FWI), and Daily Severity rating (DSR). Each of these indices are produced using two calculation methods applied at the beginning of fire season start-up. The first method used the default DC value (DC=15) to start-up the FWI System calculation and only accounted for the longest stretch of active fire season each year (as determined by Wotton and Flannigan, 1993). The second method used the overwintered DC value, calculated from the DC value of the last day of the previous fire season and a percentage of overwinter precipitation, and accounted for all periods of fire season throughout the year. We recommend users of this data use indices where DC has been overwintered in regions where the fire season shuts off for winter and where low overwinter precipitation occurs (eg. parts of western Canada, the western US and the Siberian Boreal forest). References: Copernicus Climate Change Service (C3S) (2017): ERA5: Fifth generation of ECMWF atmospheric reanalyses of the global climate . Copernicus Climate Change Service Climate Data Store (CDS), Accessed June 20^th 2019. https://cds.climate.copernicus.eu/cdsapp#!/home Wang, X., Wotton, B. M., Cantin, A. S., Parisien, M. A., Anderson, K., Moore, B., & Flannigan, M. D. (2017). cffdrs: an R package for the Canadian forest fire danger rating system. Ecological Processes, 6(1), 5. Wotton, B. M., & Flannigan, M. D. (1993). Length of the fire season in a changing climate. The Forestry Chronicle, 69(2), 187-192.本数据集由加拿大自然资源部（Natural Resources Canada）开发，以欧洲中期天气预报中心（European Centre for Medium-range Weather Forecasts, ECMWF）的ERA5-HRS再分析产品（哥白尼气候变化服务局，2017）作为输入数据，用于加拿大森林火险等级系统R程序包（Wang等人，2017）。本数据集提供了加拿大火险天气指数（Fire Weather Index, FWI）系统的燃料湿度与火行为指数格点数据，涵盖细燃料湿度码（Fine Fuel Moisture Code, FFMC）、达夫湿度码（Duff Moisture Code, DMC）、干旱码（Drought Code, DC）、初始蔓延指数（Initial Spread Index, ISI）、累积指数（Build-Up Index, BUI）、火险天气指数（Fire Weather Index, FWI）以及日严重度等级（Daily Severity rating, DSR）。 上述指数均采用两种计算方法，于林火季启动初期开展计算。第一种方法以默认干旱码值（DC=15）启动FWI系统计算，仅统计每年林火活跃期的最长时段（由Wotton与Flannigan于1993年确定）；第二种方法则使用越冬干旱码值，该值由上一林火季最后一日的干旱码值与越冬降水占比计算得出，可覆盖全年所有林火季时段。 本数据集使用者应在林火季因冬季休停且越冬降水较少的区域（如加拿大西部部分区域、美国西部以及西伯利亚泰加林），采用越冬干旱码计算得到的指数。 参考文献： 哥白尼气候变化服务局（Copernicus Climate Change Service, C3S）（2017）：ERA5：ECMWF第五代全球大气再分析资料。哥白尼气候变化服务局气候数据存储库（CDS），2019年6月20^th日访问。https://cds.climate.copernicus.eu/cdsapp#!/home Wang, X., Wotton, B. M., Cantin, A. S., Parisien, M. A., Anderson, K., Moore, B., & Flannigan, M. D. (2017). cffdrs: an R package for the Canadian forest fire danger rating system. Ecological Processes, 6(1), 5. Wotton, B. M., & Flannigan, M. D. (1993). Length of the fire season in a changing climate. The Forestry Chronicle, 69(2), 187-192.