bc climate 071004

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UNCERTAINTIES IN BLACK CARBON EMISSIONS AND MODEL PREDICTIONS: A SOUTH ASIAN PERSPECTIVE Chandra Venkataraman Department of Chemical Engineering Indian Institute of Technology, Bombay, India Collaborators: M. Shekar Reddy, Gazala Habib, Manish Shrivastava, Shubha Verma-IIT Bombay Olivier Boucher, Jean-François Léon, Bertrand Crouzille - LOA, France Toni Miguel, Arantza Fernandez, Sheldon Friedlander - UCLA Presented at “Black Carbon Emissions and Climate Change: A Technical Workshop,” San Diego, USA, October 13-15, 2004

OUTLINE: 

OUTLINE Emissions estimation: industrial/transport, residential, open burning Level of sectoral detail Fuel composition and technology information Developing / measuring emission factors Assumptions in spatial distributions Seasonal and interannual variability Estimated uncertainties and strategies for their reduction BC transport and radiative forcing using a general circulation model Evaluation of model predictions Sensitivity study Optical depth and radiative forcing

EMISSIONS ESTIMATION APPROACH: 

EMISSIONS ESTIMATION APPROACH

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FUEL CONSUMPTION - INDIA Fossil: 9,411 PJ (1 PJ = 1015 J) Biofuel/biomass: 8,213 PJ

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IND/TRA: SECTORAL DETAIL Others Large point sources Utilities (power) Iron and steel Cement Fertilisers & Refineries Plant fuel use Transport Road Rail Residential Rural Urban Industry BC emissions @ 0.250 x 0.250 resolution Plant Tech./ APCD EF Appropriate proxy EF EF EF BC emissions Petroleum fuels Gaseous fuels Coal/Lignite Fuel Use Data/ State Level

IND/TRA: FUEL & TECHNOLOGY ANALYSIS: 

IND/TRA: FUEL & TECHNOLOGY ANALYSIS e.g. ELECTRIC UTILITIES

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IND/TRA: FUEL & TECHNOLOGY ANALYSIS e.g. TRANSPORT Vehicle count in 22 major cities

IND/TRA: EMISSION FACTORS: 

IND/TRA: EMISSION FACTORS Size Specific PM Emission Factors for Coal Combustion in Dry Bottom Boilers * ESP: Electrostatic Precipitators A= coal ash weight percent, as fired. For example, if coal ash weight is 40%, then A=40. Source: U.S. EPA AP-42 Compilation of emissions factors for stationary sources BC/PM ratios for Coal Boilers: 2.2-6.4% (Henry and Knapp, 1980; Shibaoka, 1986; Veranth, 2000)

IND/TRA: EMISSION FACTORS: 

Road Transport: PM, BC/PM, OC/PM Literature reported measurements for diesel (LDV, HDV) and petroleum (leaded, unleaded) vehicles Rail Transport: Values reported by US EPA [1998]. aLDV: heavy duty vehicles; b LDV: light duty vehicles; c WCC: without catalytic converters IND/TRA: EMISSION FACTORS

IND/TRA:SPATIAL &SEASONAL DISTRIBUTIONS: 

IND/TRA:SPATIAL & SEASONAL DISTRIBUTIONS Assumed no seasonal variability in industrial and transport emissions. Proxies from state to district and down to 25 km x 25 km resolution Point sources: - district power generation, cement / steel / industrial production. Transport: road - vehicle population in 22 cities. - balance district urban population. rail - district geographical area.

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Activity data statistics : 20-40% Emission factors : - applicability of non-region-specific emfacs? - validation needed through measurements. - factor of 4-5 (300-400%). Needs : Transport > modelled emission factors. > on-road emissions measurement (mixed fleet, urban, interstate). > possible fuel-adulteration effects on emissions. Brick kilns > emissions from representative kiln types. IND/TRA: UNCERTAINTIES

RESIDENTIAL: 

RESIDENTIAL Energy surveys : high uncertainty and low representative-ness for biofuels (kg capita-1 day-1). User population : not estimated. Unquantifiable uncertainties. Highly uncertain emission factors for biofuels.

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RES: SECTORAL/TECHNOLOGY DETAIL

RES: BIOFUEL ACTIVITY DATA: 

RES: BIOFUEL ACTIVITY DATA

RES: EMISSION FACTOR MEASUREMENT: 

RES: EMISSION FACTOR MEASUREMENT Stove fuel system used  Traditional single pot mud stove 5-wood species, dung-cake and 10-crop waste types High and low power phases Dilution sampler Optimized for aerosol stabilization Mass of fuel, duct velocity, temperatures in combustion zone, duct and plenum recorded each minute Pollutant measurement PM2.5: Multi-stream cyclone sampler OC-BC: Thermal optical transmittance (S. California Particle Centre and Supersite) SO2, NO2, ions, trace elements and absorption Dilution sampler Burn cycle Multi-stream aerosol sampler AIHL Cyclone Equilibration cylinder Inlet for air Filter holders Cyclone outlet pipe Connection to Pump Critical Orifices for flow control

OC-EC MEASUREMENT: 

OC-EC MEASUREMENT Typical thermogram OC artifact measurement

RES: EMISSION FACTORS FROM COOKING : 

RES: EMISSION FACTORS FROM COOKING

RES: BLACK CARBON EMISSIONS: 

RES: BLACK CARBON EMISSIONS 81% 17% 2% 0.34%

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Activity data statistics : - cooking (various fuel categories) ~45-85% Emission factors : - cooking (traditional stoves / various fuel categories) ~20-100% Needs : - water heating / space heating ~unknown - emission factors for mixed fuel use ” - emissions from improved cooking technologies ” - outdoor penetration of residential emissions ” RES: UNCERTAINTIES

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OPEN BURNING MODIS vegetation map Forest / grassland / shrubland: E = A . AFL . CE . EF uncertain A (area under different land types). uncertain AFL, CE. seasonal / interannual variability. shifting cultivation practices (Jhum) Agricultural waste burning in croplands: E = CP . RPR. F. DM. CE. EF uncertain F, CE. systematic spatial/temporal variation.

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OB: INTERANNUAL-SEASONAL VARIABILITY i j ii jj Integrating bottom-up and top-down approaches: biomass burnt from bottom up methods. temporal / spatial distribution from active fires and vegetation data. high resolution, co-location. Annual Emissions per grid (bottom-up estimate)

OB: AG WASTE MASS BALANCE: 

OB: AG WASTE MASS BALANCE

OB: UNUTILIZED AG WASTE : 

OB: UNUTILIZED AG WASTE Total unutilized crop waste 116 (60-217) Tg y-1

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AG WASTE: SEASONAL EMISSIONS 704 114 306 116 x 103

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AG WASTE: SPATIAL-TEMPORAL VARIABILITY

INDIA BC EMISSIONS SUMMARY (Gg y-1): 

INDIA BC EMISSIONS SUMMARY (Gg y-1) Amean and range; buncertainty at 95% CI; conly for forest fire; dUpgraded for current base year using rural population as proxy.

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Simulations of the INDOEX “intensive field phase” in the LMDZ-GCM Introduction of multi-component aerosols: sulphate, black carbon, organic matter, fly-ash, dust (<1µm; 1-10µm) and sea-salt (8 size bins). India emissions at 0.25ox0.25o with ground level and elevated sources (MSR/CV 2002a, b). Asia emissions (Streets et al. 2003). Seasonal/inter-annual BC emissions from biomass open burning distributed using ATSR fire counts. Nudged to ECMWF winds from Nov 1998 to March 1999. Parameterisation for carbonaceous aerosol growth from hydrophobic to hydrophilic state. Wavelength depended aerosol optical properties at different relative humidity.

Evaluation with measurements:Surface concentrations at Goa (15.5N, 73.8E): 

Evaluation with measurements: Surface concentrations at Goa (15.5N, 73.8E) Measurements: Chazette, 2003

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Ron Brown cruise track Evaluation with measurements: Surface concentrations over ocean (Ron Brown)

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Sensitivity to Asian BC emissions: Surface concentrations at KCO 4.9N, 73.5E (Chowdhury et al., 2001)

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Sensitivity to Asian BC emissions: AOD

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Sensitivity to Asian BC emissions: SSA 15.5N, 73.8E 4.9N, 73.5E

Sensitivity to Asian BC emissions: Radiative forcing: 

TOA SUR ATM CONTROL 2 x BC POLDER Sensitivity to Asian BC emissions: Radiative forcing

SUMMARY / NEEDS: 

SUMMARY / NEEDS Uncertainties in S. Asian BC emissions can be constrained within factor of 2 (or 100%). - emission factors ~ vehicle classes (on-road emissions), industrial plants, brick kilns, etc. - open burning amounts and seasonal / interannual variability. - missing sources ~ agro-industries e.g. spice / tea drying, small-scale industries - restaurants/ confectioners, glass and bangle making, crematoriums. Present model estimates show systematic under-prediction. - restricted to winter monsoon – check seasonal / interannual variability. - wind data that drive model. - assimilate satellite derived AOD. Ambient measurements. - network of aethalometer measured “BC” being set up. - need ambient measurements.

RELATED PAPERS: 

RELATED PAPERS M.S. Reddy and C. Venkataraman (2002). Inventory of Aerosol and Sulphur Dioxide Emissions from India: I – Fossil Fuel Combustion, Atmospheric Environment, 36 (4), 677-697. M.S. Reddy and C. Venkataraman (2002). Inventory of Aerosol and Sulphur Dioxide Emissions from India: II – Biomass Combustion, Atmospheric Environment, 36 (4), 699-712. G. Habib, C. Venkataraman, M. Shrivastava, R. Banerji, J. Stehr and R. Dickerson (2004). New methodology for estimating biofuel consumption for cooking: Atmospheric emissions of black carbon and sulfur dioxide from India, Global Biogeochemical Cycles, 18, GB3007, doi:10.1029/2003GB002157. M.S. Reddy, O. Boucher, C. Venkataraman, S. Verma, N. Bellouin and M. Pham (2004). GCM estimates of aerosol transport and radiative forcing during INDOEX, Journal of Geophysical Research, 109, D16205, doi:10.1029/2004JD004557. C. Venkataraman, G. Habib, A. Eiguren-Fernandez, A.H. Miguel and S.K. Friedlander (2004). Carbonaceous aerosol emissions from residential biofuel combustion in S. Asia and climate implications, submitted. G. Habib, C. Venkataraman, T.C. Bond and J.J. Schauer, A. Eiguren-Fernandez, A.H. Miguel, S.K. Friedlander (2004). Primary particle emissions biofuel combustion: Chemical composition, size distribution and optical properties, in preparation.