Global Estimates of Ambient PM2.5 Concentrations from Satellite AOD Aaron van Donkelaar with contributions from: Randall Martin, Brian Boys, Crystal Weagle, and Graydon Snider VIIRS Aerosol Science and Operational Users Workshop November 21-22, 2013

PM2.5 affects human health and longevity Life expectancy increases 7 months per 10 μg/m3 decrease in long-term exposure PM2.5 regulation achieved largest gains of all U.S. Federal Regulation Dominates global environmental mortality by 2030 Particulate Matter Ground-level Ozone Unsafe Water Supply and Sanitation Indoor Air Pollution Malaria 0.0 1.0 2.0 3.0 4.0 Deaths (millions of people) OECD, 2012 2010 2030 2050

Locations of Publicly Accessible Long-Term PM2.5 Monitoring Sites Vast Regions Have Insufficient Measurements for Air Pollution Exposure Assessment Locations of Publicly Accessible Long-Term PM2.5 Monitoring Sites Emerging Network Monitor locations can be driven by compliance objectives ~1 site / 10,000 km2 in continental US & southern Canada

Previous Global Burden of Disease Report for 2000 Impaired by Insufficient Global Observations of Fine Particulate Matter (PM2.5) Estimate air pollution in urban areas causes: ~1 million deaths (~1%) Could not estimate effects outside of urban areas for 2000 report Could this be improved with satellite remote sensing? Cohen et al., 2005

AOD is related to PM2.5 …but how to separate surface aerosol from column concentrations? PM2.5 / AOD ratio is a function of: vertical structure aerosol type/hygroscopicity meteorology Multiple approaches: surface monitors calibration empirical relations model output 20 80 140 PM2.5 / AOD [μg/m3] GEOS-Chem v8-01-04

Significant agreement with coincident ground measurements over NA MODIS AOD 0.39 MISR AOD Combined AOD 0.61 Combined PM2.5 0.77 18 16 14 12 10 8 6 4 2 Annual Mean PM2.5 [μg/m3] (2001-2006) Satellite Derived Satellite-Derived [μg/m3] In-situ In-situ PM2.5 [μg/m3] van Donkelaar et al., EHP, 2010

Satellite-derived PM2.5 shows global agreement Outside Canada/US N = 244 (84 non-EU) r = 0.83 (0.83) Slope = 0.86 (0.91) Bias = 1.15 (-2.64) μg/m3 CTM Agreement: r = 0.63 (0.72) slope = 0.54 (0.60) bias = 8.89 (2.45) μg/m3 Satellite-Derived PM2.5 (2001-2006) [μg/m3] 0 5 10 15 20 50 80 van Donkelaar et al., EHP, 2010

Global impact of global data Global Burden of Disease 2010 488 authors from 303 institutions in 50 countries Inclusion of rural populations PM2.5 causal role in 3 million deaths per year Lim et al., Lancet, 2012 Inform Epidemiological Studies: Global childhood asthma (Anderson et al., 2012) Lung cancer in Canada (Hystad et al., 2012) Mortality in California (Jerrett et al., 2013) Diabetes (Brook et al., 2013; Chen et al., 2013) Global adverse birth outcomes (Fleisher et al., in press) Hypertension (Chen et al., in press) Low PM2.5 cardiovascular mortality (Crouse et al., 2012) Crouse et al., EHP, 2012

Global in situ monitors are sparse ...and far from AERONET PM2.5 estimates accuracy impacted by AOD retrieval Simulated aerosol vertical profile Mass to extinction conversion Sampling (clouds/snow) Difficult to evaluate error sources SPARTAN network collocates PM2.5 and AOD measurements Satellite-derived PM2.5 evaluation, analysis, www.spartan-network.org Airphoton PM2.5 (Vanderlei Martins) Filter PM2.5 Filter PM10 3-λ Nephelometer AOD from CIMEL Sunphotometer (e.g. AERONET)

CALIOP allows vertical profile correction GEOS-Chem CALIOP Altitude [km] 5 4 3 2 1 0 2 4 6 8 0 0.5 1 1.5 1.9 Relative Profile Ratio Relative Profile Determine profile accuracy: Compare with CALIOP space-borne lidar Match optical properties Long-term (2006-2011) comparisons 2 1.5 1 0.5 𝑒𝑥𝑡 𝑠𝑢𝑟𝑓 𝐴𝑂𝐷 𝐺𝐶 𝑒𝑥𝑡 𝑠𝑢𝑟𝑓 𝐴𝑂𝐷 𝐶𝐴𝐿 June-August 2006-2011 van Donkelaar et al., JGR, 2013

Long-term retrievals allow trends combined MODIS, MISR and SeaWiFS-based PM2.5 1998-2012 PM2.5 [μg/m3] van Donkelaar et al., in prep.

Global exposure and trends vary by region +0.6 Percent of Population [%] 100 80 60 40 20 5 10 15 25 35 50 100 Annual Mean Exposure [μg/m3] 2012 2005 1998 Year IT1 IT3 IT2 AQG 1998-2012 exposure trend [μg/m3/yr] Europe, Central -0.2 Asia, South +1.0 Western North America, High Income -0.3 East +1.4 North Africa, Middle East +0.4 100 80 60 40 20 Percent of Population [%] 5 10 15 25 35 50 100 Annual Mean Exposure [μg/m3] van Donkelaar et al., in prep

Some Ongoing & Future Activities Environmental Performance Index Operational AIRNow Satellite Data Processor PCW/PHEOS Chinese PM2.5 Events PURE Air: Prospective Urban and Rural Epidemiological Study 1 km Optimal Estimation Retrieval Size Resolved AOD/PM2.5 Calculation ESCAPE - European Study of Cohorts for Air Pollution Effects

Extras

Short-term agreement during extreme events – Moscow 2010 120 100 80 60 40 20 PM2.5 [μg/m3] Before Fires July 7- July 29, 2010 During Fires 35°E 45°E 55°E MODIS-based In Situ PM2.5 In Situ PM2.5 from PM10 r =0.92, slope=1.06 1000 800 600 400 200 PM2.5 [μg/m3] Jul-14 Jul-19 Jul-24 Jul-29 Aug-03 Aug-08 Aug-13 Aug-18 MODIS/Aqua Aug 7th, 2010 Moscow 50 km van Donkelaar et al., AE, 2011

Error in Smoothed & Bias-corrected (2004, 2006, 2008) Daily Satellite-based Estimates in North America Benefit from Spatial Smoothing & Bias Correction Bias Corrected & Smoothed, Jun 27, 2005 Error in Original (2004, 2006,2008) Error in Smoothed & Bias-corrected (2004, 2006, 2008) van Donkelaar et al., ES&T, 2012

Simulated values can constrain retrievals Optimal estimation constrains AOD retrieval by error: GEOS-Chem provides: AOD/PM2.5 relationship A priori values observed TOA reflectance a priori AOD a posteriori AOD a priori error observational error Satellites provide: High resolution (0.1° × 0.1°) Observational constraint Column-integrated value Available from 2004-2011 OE PM2.5 [μg/m3] In situ PM2.5 [μg/m3] 0 10 20 30 40 40 30 20 10 15 5 OE PM2.5 [μ g/m3] 2005 van Donkelaar et al., JGR, 2013

Sampling Station Designed for Nearly Autonomous Operation Filter Cartridges Replaced Every Two Months Nephelometer (1 Hz) Resolves Satellite Overpass vs 24-hr Solar Capability 8-slot Filter Cartridge Collect PM2.5 & PM10 Cartridge Protects Filters

SPARTAN Activities at Dalhousie Analysis for Ions, Metals, Black Carbon (Ion Chromotraphy; Inductively Coupled Plasma Mass Spectrometry; Absorption ) Pre&Post Weigh Filters

SPARTAN Activities Beijing, China Dhaka, Bangladesh Kanpur, India Expansion & Supersite Development