NBIC-ACS Stage 2 Forest Fire Danger Index - projected scenario, 5%, 2% and 1% annual exceedance probabilities

McArthur Forest Fire Danger Index (FFDI) is a fire weather potential index that describes how current weather conditions and recent precipitation patterns could support a fire in forested areas. FFDI calculations are based on McArthur, A.G. (1967) and dependent on air temperature, relative humidity, wind speed and drought factor. FFDI was originally implemented as a circular slide rule that constrained the returned index between 0 and 100, where 100 was representative of the worst Australian bushfire at that time, Victoria 1939. The data provided here is unbounded.\nHere we provide predicted upper-bound FFDI values across the Australian landscape, defined for a set of annual exceedance probabilities modelled using extreme values analysis on more than 43 years of hourly data.\nThe FFDI potential rasters represent reasonable worst case extreme conditions. Specifically, the rasters represent the FFDI potential for given AEPs of 20%, 10%, 5%, 2% and 1%. These FFDI AEPs are based on the projected weather timeseries developed by NBIC using the historical regional weather reanalysis dataset BARRA-R2 [1], and CMIP6-CCAM Regional Climate Models (RCM) [2].\nThe Regional Climate Models (RCM) considered are:\n•\tACCESS ESM 1.5\n•\tEC-Earth 3\n•\tCMCC ESM2\n•\tCNRM ESM 2.1\n•\tNCAR CESM2\n•\tNorESM2 MM\nThe future climate change scenarios considered are:\n•\tShared Socioeconomic Pathway (SSP) SSP 1-26: Sustainability \n•\tSSP 3-70: Regional Rivalry\n•\tSSP 3-70: Regional Rivalry, using wind speed from the baseline scenario \nThe combination of RCMs and future climate change scenarios results in a suite of 18 projected FFDI potential datasets.\nLineage: The McArthur Forest Fire Danger Index (FFDI) data - projected scenario is calculated using the CMIP6-ERA Regional Climate Model data produced with CCAM by CSIRO (https://dx.doi.org/10.25914/rd73-4m38). Variables used are near surface air temperature, precipitation, near surface relative humidity and near surface wind speed.\nThose inputs are combined using the equations developed by Noble et al. (1980) [1] based on the work by McArthur (1967) [2]. McArthur Drought Factor is calculated using the modified formulation published in Finkele et al. (2006) [3].\nFFDI is calculated for more than 43 years of hourly weather data and then processed using extreme values analysis to model the expected FFDI values at annual exceedance probabilities.\n[1] Noble, I.R., Gill, A.M. and Bary, G.A.V., 1980. McArthur's fire‐danger meters expressed as equations. Australian journal of ecology, 5(2), pp.201-203. https://doi.org/10.1111/j.1442-9993.1980.tb01243.x\n[2] McArthur, A.G., 1967. Fire behaviour in eucalypt forests: Forestry and Timber Bureau Leaflet 107. Forestry and Timber Bureau: Canberra, Australia.\n[3] Finkele, K., Mills, G.A., Beard, G. and Jones, D.A., 2006. National gridded drought factors and comparison of two soil moisture deficit formulations used in prediction of Forest Fire Danger Index in Australia. Australian Meteorological Magazine, 55(3), pp.183-197.