A high-resolution reanalysis of global fire weather from 1979 to 2018 – overwintering the Drought Code
<p>We present a global high-resolution calculation of the Canadian Fire Weather Index (FWI) System indices using surface meteorology from the ERA5 HRES reanalysis for 1979–2018. ERA5 HRES represents an improved dataset compared to several other reanalyses in terms of accuracy, as well as spati...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-08-01
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| Series: | Earth System Science Data |
| Online Access: | https://essd.copernicus.org/articles/12/1823/2020/essd-12-1823-2020.pdf |
| Summary: | <p>We present a global high-resolution calculation of the Canadian Fire Weather
Index (FWI) System indices using surface meteorology from the ERA5 HRES
reanalysis for 1979–2018. ERA5 HRES represents an improved dataset compared
to several other reanalyses in terms of accuracy, as well as spatial and
temporal coverage. The FWI calculation is performed using two different
procedures for setting the start-up value of the Drought Code (DC) at the
beginning of the fire season. The first procedure, which accounts for the
effects of inter-seasonal drought, overwinters the DC by adjusting the fall
DC value with a fraction of accumulated overwinter precipitation. The second
procedure sets the DC to its default start-up value (i.e. 15) at the start
of each fire season. We validate the FWI values over Canada using station
observations from Environment and Climate Change Canada and find generally
good agreement (mean Spearman correlation of 0.77). We also show that
significant differences in early season DC and FWI values can occur when the
FWI System calculation is started using the overwintered versus default DC
values, as is highlighted by an example from 2016 over North America. The
FWI System moisture codes and fire behaviour indices are made available for
both versions of the calculation at <a href="https://doi.org/10.5281/zenodo.3626193">https://doi.org/10.5281/zenodo.3626193</a> (McElhinny et al., 2020), although
we recommend using codes and indices calculated with the overwintered DC,
unless specific research requirements dictate otherwise.</p> |
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| ISSN: | 1866-3508 1866-3516 |