“Unde Fuligo?” Aerosol Black Carbon Tony Hansen Magee Scientific, Berkeley, CA Why are atmospheric aerosols important? • Public health – disease & death • Climate change – local, regional and global • Precipitation – reduction of rainfall • Visibility – also, reduction of sunlight for agriculture • Damage to cultural heritage (buildings, monuments, art) 2 U.S. Government Agency Declarations • Public Health Diesel Particulate Matter is a listed Air Toxic • Climate Change Black Carbon is a listed Greenhouse Agent 3 Official Recognition UK 2011 OECD 2016 USA 2012 WHO 2016 EU 2013 CCAC 2013 4 Good Public Policy requires Good Scientific Data 5 Why are atmospheric aerosols important? • Public health – disease & death • Climate change – local, regional and global • Precipitation – reduction of rainfall • Visibility – also, reduction of sunlight for agriculture • Damage to cultural heritage (buildings, monuments, art) 6 Loss of life expectancy in Europe CAFE Report, EU Commission, 2000 7 Health impact of Fine Particulates If 2 areas of Central and Southern California would simply meet existing Air Quality Standards : savings $28,000,000,000 per year ( $2,000 / person ) • 3,860 fewer premature deaths among those age 30 and older • 13 fewer premature deaths in infants • 1,950 fewer new cases of adult onset chronic bronchitis • 3,517,720 fewer days of reduced activity in adults • 2,760 fewer hospital admissions • 141,370 fewer asthma attacks • 1,259,840 fewer days of school absence • 16,110 fewer cases of acute bronchitis in children • 466,880 fewer lost days of work • 2,078,300 fewer days of respiratory symptoms in children • 2,800 fewer emergency hospital visits More premature death in Los Angeles from Air Pollution than Car Accidents Hall et al., Cal State University Fullerton, Nov. 2008 8 Cities are Choking around the World WORST : Asia, BC = 10 ~ 100 µg/m³. 2,000,000,000 people 9 Aerosol Black Carbon covers continents Picture taken at ~ 1000 m. altitude over New Delhi, India: early morning. City is invisible: solar radiation reaching the ground is reducing ~ 5% per decade over the entire country. ~ 12% of Delhi population ( > 3 million people) have respiratory disease . 10 Why are atmospheric aerosols important? • Public health – disease & death • Climate change – local, regional and global • Precipitation – reduction of rainfall • Visibility – also, reduction of sunlight for agriculture • Damage to cultural heritage (buildings, monuments, art) 11 Climate Change Effects of Aerosols “The best estimate of climate forcing by Black Carbon is 1.1 W m-2. There is a very high probability that Black Carbon emissions have a positive forcing and warm the climate. “Black carbon reduces aerosol albedo, causes a reduction of cloud cover, and reduces cloud particle albedo. All of these effects cause warming.” Bounding the role of Black Carbon in the climate system T. Bond et al. JGR (2013) 12 Why are atmospheric aerosols important? • Public health – disease & death • Climate change – local, regional and global • Precipitation – reduction of rainfall • Visibility – also, reduction of sunlight for agriculture • Damage to cultural heritage ( buildings, monuments, art ) 13 Suppression of Precipitation - California “Urban air pollution and industrial air pollution have been shown qualitatively to suppress rain and snow . Here, precipitation losses over topographical barriers downwind of major coastal urban areas in California .. that amount to 15%–25% of the annual precipitation are quantified . …. The evidence includes significant decreasing trends of .. precipitation during the twentieth century in polluted areas in line with increasing emissions during the same period, whereas no trends are observed in similar nearby pristine areas.” Quantifying Precipitation Suppression Due to Air Pollution A. Givati and D. Rosenfeld, J. Applied Meteorology 43, 1038-1045, (2004) 14 Why are atmospheric aerosols important? • Public health – disease & death • Climate change – local, regional and global • Precipitation – reduction of rainfall • Visibility – also, reduction of sunlight for agriculture • Damage to cultural heritage ( buildings, monuments, art ) 15 1953 : Air pollution cancels soccer game 16 2013 : Air pollution closes Beijing Airport 17 Influence of air pollution on Agriculture • In China, where air pollution is serious, it may reduce the production of rice and wheat Rice: up to 5% loss Wheat: over 10% loss Effect of heavy haze and aerosol pollution on rice and wheat production in China Tie et al., Nature Sci. Rep. 6, 29612 (2016) 18 Aerosol Black Carbon : Need for Data • Climate impact of BC is second only to CO 2 • Ground-level BC concentrations that affect public health are highly variable • BC emissions can not be predicted: must be measured • To manage Climate and Health impacts, we need data : BC ( X, Y, Z, t ) 1919 Black Carbon : Formation during combustion 20 Emissions of Black Carbon • BC / (kilogram fuel) is unpredictable * 10³ • Quantity of fuel → CO2 • Quality of combustion → BC 21 The Aethalometer™ - since 1979 • Draw air sample continuously through filter, collect aerosol. • Illuminate, measure rate of decrease of optical transmission. • Calculate rate of increase of ‘Attenuation’ (‘ATN’) • ATN is proportional to loading of Black Carbon • Calculate concentration of BC in air stream. 22 Aethalometer – Continuous optical analysis Air stream containing BC particles Reference I0 BC Sensing I Light Source Light Detectors Filter collects particles continuously : Gradually becomes darker and darker 23 Measurement Principle – Optical Absorption –( b a · D ) Beer’s Law : I = I0 e I0 is incident intensity; I is transmitted intensity D is total density of material traversed; ba is absorption coefficient. Measure I and I0 ; use known value of ba ; determine D → measure amount of absorbing material 24 Advantages / Attributes of Optical Analysis • Instantaneous → real-time data • Non-destructive • Mobile / Portable / Personal • Added dimension - wavelength 25 Wide Dynamic Range of actual measurements Clean air from ocean: BC < 50 ng/m³ Clean air : Berkeley, California 1,400 370 470 520 590 660 880 950 Highly Polluted Air : BC >100 µg/m³ 1,200 Polluted Air : Kolkata, India 1,000 140,000 880 800 120,000 Maximum : 600 100,000 >100 µg/m³ BC, ng/m3 BC, 400 Minimum : 80,000 0.03 µg/m³ 200 ng/m3 60,000 0 0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00 BC, 40,000 17 ~ 18 July 2011 20,000 0 0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00 16 Dec 2009 26 Time pattern analysis to identify sources • Measurements at single fixed point • Analyze temporal patterns • Different sources have different temporal patterns London Germany China 27 Aethalometer ® case study : traffic emission patterns Urban roadside emissions study ..…. London Time series from roadside location in London : 3 months of data on 5-minute time-base Problem: Derive meaningful conclusion from 19,125 data points. Gather into overlays : 12 weekly cycles of 5-minute data Data courtesy of P. Quincey, NPL, UK 28 Aethalometer ® case study : traffic emission patterns Urban roadside emissions study ..…. London Calculate difference between [ Workdays ] and [ Sundays ] Compare results with traffic activity 29 The ‘Model AE33’ Aethalometer : 2012 30 Optical Calibration of Aethalometer • Optical calibration against NIST Standard Reference Material 8785 31 In-field Validation of AE33 Aethalometer • Optical validation with NIST-traceable “Neutral Density” Transfer Standard Kit 32 Official Certificates of Approval 33 Recommendation by US EPA J. Air & Waste Manage. Assoc. 58 :164–195 (2008) Continuous Monitoring Techniques for Particulate Matter Mass and Chemical Components: EPA’s Particulate Matter Supersites Program Paul A. Solomon U.S. Environmental Protection Agency , Office of Research and Development, Las Vegas, NV SUMMARY AND RECOMMENDATIONS Significant advances in the measurement of the chemical and physical properties of PM have occurred as an outcome of the Supersites Program and related studies over the last 5–7 yr. Results from these studies indicate that continuous monitoring methods often provide improved estimates of what is in the air as compared with current standard filter-based methods. Of considerable importance is the near-real-time availability of these data , often at hourly time resolution or shorter. Particle Absorption/BC . The Aethalometer provides direct measures of the light absorbing carbon in aerosols as an absorption value (1/m). The measure in ambient concentration units is referred to as BC, which is related to EC being measured thermally. The Aethalometer is robust and widely used in monitoring networks with relatively well-defined Recommendation: — Aethalometer 34 Advantages / Attributes of Optical Analysis • Instantaneous → real-time data • Non-destructive • Mobile / Portable / Personal • Added dimension - wavelength 35 From Black& to Color 36 High emissions from wood burning • Wood/biomass is a ‘sustainable fuel’ ( CO 2 perspective) • Biomass burning is a major energy source in rural areas • Individual stoves have low efficiency, high emissions • Biomass smoke contains ‘ Brown Carbon ’ 37 Analysis at multiple wavelengths • Aethalometers provide analysis at 7 wavelengths : 370, 470, 520, 590, 660, 880 and 950 nm • “Black” materials absorb uniformly across the spectrum: the 880 nm analysis is quantitative for ‘Black Carbon’. • Other species – aromatic organic compounds – sometimes called “Brown Carbon” - can show increased absorption