EMM Seminar - 21 October 2011

Smith, Wooster, Tattaris et al. (2010) flaming fires Just recycled sunlight? Biomass burning and its influence on global climate change Thomas Smith Environmental Monitoring and Modelling Group Department of Geography, King's College London smouldering fires WARMER CLIMATE Albedo Aerosols Greenhouse gases >soil moisture deficit >soil temperatures evapotranspiration permafrost thaw self-heating tendency ignition probability Tropospheric Ozone black carbon scatter black carbon on snow land surface change Questions? burn period: burn period: Smokey infrared pathways: FTIR spectroscopy for field study of biomass burning emissions RFs from Bowman et al., (2009) CO2 CO2 CO2 sugars O2 CO2 increase rate (ppm/year) regrowth period: 3.5-4.5 million km² burns each year releasing 2-4 Pg C (deforestation fires = 0.65 Pg) How are global emissions calculated? burned area (percent/year) carbon emissions (g C/m²/year) Emission of x = burnt area × mass combusted × EMISSION FACTOR of x (kg) (m²) (kg/m²) (g/kg combusted) Aircraft Sampling Ground Sampling OPFTIR Plume ageing Bias to convective (flaming) plume Expensive Point sampling Need to represent both flaming and smouldering Sample transportation Live Demo OPFTIR Live Demo How do we get useful information from these spectra? Model spectrum using HITRAN... fit the model to the measurement In the lab... Case Study: Australia Live Demo Live Demo Emission Ratios Emission Factors The IPCC Good Practice Guidance (2000) argue that: "Since the emission factor for CH4 can decrease by 50-75% as the burning season progresses, it is strongly suggested that each inventory agency collect...[data]...from the early dry season to the late dry season." [Hence]... "It is desirable to develop seasonal-dependent activity data and the emission factors of CH4 and N2O from savanna burning in various savanna ecosystems in each country if data are available." regrowth period: Model inputs: spectral window instrument parameters temperature pressure apriori gas amounts Outline Introduction to the nature of biomass burning (10 mins) How do we measure emissions? (20 mins) Case Study: NT, Australia (8 mins) Thanks: NERC/ESRC, CSIRO, Charles Darwin University, NERC MSF, NERC FSF, Northumberland and Dorset Fire and Rescue Services, Canadian Forest Service Martin Wooster, Maria Tattaris, Ronan Paugam, Melissa Lestari Meigh Fire Radiative Power and fuel consumption Geostationary fire detection over Africa & Europe Fire Radiative Power & fuel consumption Fire Radiative Power derivation & evaluation Use of FRP in smoke pollution forecasting SEVIRI Characteristics 4.8 km pixel size at SSP 3.0 km sampling distance 15 minutes imaging freq. 11 spectral channels + 1 km VIS Meteosat Disk Geostationary Fire Detection Fire Pixel and Fire Cluster Counts Absolute Minimum Minimum Size Saturation point xx(BT = 335 K) Algorithm Performance Characteristics Current Primary Approaches to Emission Inventory *Seiler, W. & Crutzen, P.J. (1980) Estimates of gross and net fluxes of carbon between the biosphere and the atmosphere from biomass burning, Clim. Change, 2, 207-247 Carbon (and other) emissions estimates generally based on estimate of total Fuel Biomass Consumed: Calculated via the simple equation first proposed in 1980*: Total Fuel (Biomass) = Area x Fuel x Combustion Consumed (kg) Burnt (m²) Load (kg/m²) Completeness (%) Emission of Trace = Fuel x Emissions Factor Gas Species X (g) Consumed (kg) Species X (EF, g/kg) (e.g. CO2, CO, CH4) Example of Airborne Fire Signatures (SAFARI 2000, NASA) smoke Fires have very high temperatures compared to ambient surroundings These high temperatures result in very intense radiant energy emissions particularly in the middle IR (3-5 microns) spectral region. Fire MIR emission so strong that fires of  0.1-1% of a pixel are detectable. Signal strength can be used as a method of quantifying the fires ‘intensity’ Digital scales h=10m weather station Vegetation fuel Thermal camera (λ=3.9 μm) + Optical video camera FRP Fuel Mass Emission Rate of Species X = FRP * Scaling Factor * Emission Factor Species X (kg/sec) (MW) (kg/MW) (g/kg) Fire Radiative Power & Energy: Relationship to Fuel Consumption Fire Map for African Sahel (04/02/04 – 14/02/04) 1 3 6 9 14 Day of Feb 2004 Fire Radiative Energy = 4.2 x 1010 MJ Estimated Total Fuel Biomass Consumed = 27 x 106 tonnes Estimated Total Carbon Release = 13 x 106 tonnes Apply appropriate EF to estimate CO2, CO, NOx, SO2, PM etc