1. ResultsBackground
We parameterize fires on a global scale to obtain:
1. Burnt Area
2. Burnt Carbon
3. Emission of key species
Our goals are:
• To study the feedback of fire emissions with
the climate system
• To assess the impact of fires in past/future
climates
• To fully integrate fires within the Earth System
Methods & Materials Our model sits within the Met Office’s Unified Model, through its land surface
component (JULES) and can be summarized in these two processes:
Conclusions
Acknowledgements
References
[1] Pechony, O., Shindell, D.T., 2009. Fire parameterization on a global
scale. J. Geophys. Res. 114, D16115. doi:10.1029/2009JD011927
[2] Ward, D.S., Kloster, S., Mahowald, N.M., Rogers, B.M., Randerson,
J.T., Hess, P.G., 2012. The changing radiative forcing of fires: global
model estimates for past, present and future. Atmos. Chem. Phys. 12,
10857–10886. doi:10.5194/acp-12-10857-2012
[3] Van der Werf, G.R., Randerson, J.T., Giglio, L., Collatz, G.J., Mu, M.,
Kasibhatla, P.S., Morton, D.C., DeFries, R.S., Jin, Y., van Leeuwen, T.T.,
2010. Global fire emissions and the contribution of deforestation,
savanna, forest, agricultural, and peat fires (1997–2009). Atmos. Chem.
Phys. 10, 11707–11735. doi:10.5194/acp-10-11707-2010
[4] Giglio, L., Randerson, J.T., van der Werf, G.R., 2013. Analysis of daily,
monthly, and annual burned area using the fourth-generation global
fire emissions database (GFED4). J. Geophys. Res. Biogeosci. 118, 317–
328. doi:10.1002/jgrg.20042
We thank NERC and the Met Office for
ongoing financial support.
Interactive Fire and Emission algorithm for Natural envirOnments
INFERNO
by Stéphane Mangeon (Imperial College London), Apostolos Voulgarakis (Imperial College London) and Gerd Folberth (Met Office)
BA = (Ign) es (1-RH/100) e-ɸ
Soil moisture content (as a
fraction of saturation) Ubiquitous
(2 m2 per m2 per s)
EX = EFX BA CVEG CE
Emissions X:
Burnt Area:
Emission Factor
(kg of X emitted per kg burnt)
Burnt Area (Vegetation
and Meteorology)
Burnable Biomass per
m2 (Vegetation)
Combustion Efficiency
(Vegetation)
Understanding natural phenomena influencing
atmospheric composition such as volcanic ashes
or in our case, forest fires, requires a grasp of the
earth system as a whole. And for fires in particular,
an understanding of the vegetation and weather
which seem to rule their importance.
Fig. 2 Emitted Carbon distribution across the Earth. Boreal regions and
Africa estimates are lower than GFED (observation-based) as well as
Equatorial Asia (although peat is not accounted for by INFERNO).
Regions with strong human influences are overestimated.
(Taken from [2])
Why do fires matter?
Fig. 1 Fires in the Earth System
Fig. 4 Seasonal global burnt area (m2/s) in 2003-2011. The
autumn and spring, with an under and overestimation of
burnt area when compared to GFED
Elements of note
• All results presented here use prescribed
meteorology with JULES rather than the
coupled INFERNO (um8.4) version
• In these runs we have not represented
ignitions from humans nor from thunder
• Below 2 kgC.m-2 we assume no burning
• Combustion efficiency is parameterized per
PFT (vegetation type) and scaled using the
soil moisture content
• We use proxies for most of our model, as
JULES’s litter and debris modeling is
insufficient for a physical approach.
• Agricultural, land-management and peat fires
are NOT explicitly modeled by INFERNO
We propose a parameterization for fire
occurrence to be included within the Met
Office’s UM through the JULES land surface
model.
With a global estimate of 3.76 M km2 per year
burnt by forest fires, slightly higher than the
satellite-based GFED inventory (3.44 M km2 per
year).
We predict reasonable fires on large scales and
climatologically-relevant timescales. Although,
INFERNO is less accurate in capturing the
localization and seasonality of biomass burning.
The difference in predictions following from
different meteorology (WFDEI and NCEP)
highlight the difficulty of our endeavor.
NOTE: Meteorology and Lightning can either be prescribed or provided by an atmosphere model. Population Density
needs to be prescribed. Vegetation and associated fluxes are modeled by JULES (or another land surface model)
Saturation vapor pressure
(depends on Temperature)
Relative Humidity
Ignitions:
Prescribed
or Modeled
Atmosphere
Weather
JULES INFERNO Vegetation
Fire outputs Emissions
(Diagnostics)
Burnt Area
Burnt Carbon
Humans (Population Density)
+
Natural Ignitions (Lightning)
O
R
We run JULES’s dynamic vegetation scheme with a 10 year
spin-up. It is driven by 1 – NCEPv2 or 2 – WFDEI reanalysis
data, with a 2o grid resolution and ignitions are ubiquitous.
Model setup
Fig. 1 Mean Carbon emissions predicted by the INFERNO model with
prescribed NCEPv2 Reanalysis data for meteorology (kg/s) in 2003-2011.
While the global distribution is respected, the observation-based GFED
emissions are a lot more acute (forest fires are a sporadic phenomenon)
Fig. 3 Mean global burnt area (m2/s) in 2003-2011.