FROM AIR POLLUTION TO GLOBAL CHANGE AND BACK

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FROM AIR POLLUTION TO GLOBAL CHANGE AND BACK: a personal jouney through atmospheric chemistry

FROM AIR POLLUTION TO GLOBAL CHANGE AND BACK: a personal jouney through atmospheric chemistry Daniel J. Jacob

Graduate student at Caltech (1980 -1985) Chasing acid fog throughout California

Graduate student at Caltech (1980 -1985) Chasing acid fog throughout California

MY PATH SINCE CALTECH: focus on modeling tropospheric composition …and stuck at Harvard postdoc

MY PATH SINCE CALTECH: focus on modeling tropospheric composition …and stuck at Harvard postdoc prof. 1985 1990 1995 2000 2005 Cloud chemistry Global 3 -D model development & applications GEOS-Chem Photochemical processes Bio-atm interactions NASA aircraft missions Mesosphere Chemistry-climate interactions Intercontinental transport Satellite retrievals Stratopause Ozone layer Tropopause Stratosphere Carbon cycle Mercury SOA Troposphere

Leaders: Daniel J. Jacob and Jennifer A. Logan

Leaders: Daniel J. Jacob and Jennifer A. Logan

GEOS-Chem CHEMICAL TRANSPORT MODEL (CTM): CENTRAL ANALYTICAL TOOL IN THE GROUP • Global 3

GEOS-Chem CHEMICAL TRANSPORT MODEL (CTM): CENTRAL ANALYTICAL TOOL IN THE GROUP • Global 3 -D model of atmospheric composition with 1 ox 1 o horiz. res. , driven by assimilated meteorological data (“observed winds”) • Used by 30 groups around the world; centrally managed at Harvard • Applied to wide range of problems: carbon cycling, tropospheric oxidants, aerosols, mercury, chemistry-climate interactions… • Used by NASA to drive global chemical data assimilation, EPA to drive regional air quality simulations • Interfaced with GISS GCM for study of chemistry-climate interactions

AIRCRAFT MISSIONS WITH NASA DC-8 “Flying Laboratory”

AIRCRAFT MISSIONS WITH NASA DC-8 “Flying Laboratory”

NASA TROPOSPHERIC COMPOSITION AIRCRAFT MISSIONS INTEX-B X-A INTE Next planned mission: POLARCAT in Arctic

NASA TROPOSPHERIC COMPOSITION AIRCRAFT MISSIONS INTEX-B X-A INTE Next planned mission: POLARCAT in Arctic (spring and summer 2008)

NASA Earth & Sun Spacecraft

NASA Earth & Sun Spacecraft

WHY OBSERVE TROPOSPHERIC COMPOSITION FROM SPACE? Global/continuous measurement capability important for range of issues:

WHY OBSERVE TROPOSPHERIC COMPOSITION FROM SPACE? Global/continuous measurement capability important for range of issues: Monitoring and forecasting of air quality: ozone, aerosols Long-range transport of pollution Monitoring of sources: pollution and greenhouse gases Radiative forcing FOUR OBSERVATION METHODS: • solar backscatter • thermal emission • solar occultation • lidar

SATELLITES AND MODELS ARE LIKE PEAS AND CARROTS Example: retrieval and interpretation of formaldehyde

SATELLITES AND MODELS ARE LIKE PEAS AND CARROTS Example: retrieval and interpretation of formaldehyde data Radiative transfer model & its inverse 336 -356 nm backscattered radiance spectrum from GOME satellite instrument “L 1 data” Chemical transport model & its inverse Formaldehyde column concentrations “L 2 –L 3 data” Isoprene emission fluxes “L 4 data”

A FEW RESEARCH THEMES… • • Climate response to air pollution controls Effect of

A FEW RESEARCH THEMES… • • Climate response to air pollution controls Effect of global change on air pollution Environmental cycling of mercury Some chemical problems: bromine, organic aerosol, oxygenated organics • Inverse modeling of trace gas sources • Future satellite observations

AIR POLLUTION IN THE UNITED STATES Exceedances of the National Ambient Air Quality Standard

AIR POLLUTION IN THE UNITED STATES Exceedances of the National Ambient Air Quality Standard (NAAQS) EPA [2005] Ozone Particulate matter (aerosols) < 10 mm < 2. 5 mm

RADIATIVE FORCING OF CLIMATE, 1850 -present (BC) Air pollution - related greenhouse forcing: 0.

RADIATIVE FORCING OF CLIMATE, 1850 -present (BC) Air pollution - related greenhouse forcing: 0. 7 (CH 4) + 0. 5 (O 3) + 0. 8 (BC) = 2. 0 W m-2 …larger than CO 2 ! Cooling from scattering anthropogenic aerosols: -1. 3 (direct) – 1. 0 (clouds) = -2. 3 W m-2 …cancels half the warming! Hansen and Sato, 2001

ATMOSPHERIC OZONE AND ITS ENVIRONMENTAL EFFECTS Nitrogen oxide radicals; NOx = NO + NO

ATMOSPHERIC OZONE AND ITS ENVIRONMENTAL EFFECTS Nitrogen oxide radicals; NOx = NO + NO 2 Sources: combustion, soils, lightning Tropospheric ozone precursors Methane Sources: wetlands, livestock, natural gas Nonmethane VOCs (volatile organic compounds) Sources: vegetation, combustion CO (carbon monoxide) Sources: combustion, VOC oxidation

CLIMATE RESPONSE TO 20 th CENTURY OZONE CHANGE GISS GCM equilibrium climate simulations with

CLIMATE RESPONSE TO 20 th CENTURY OZONE CHANGE GISS GCM equilibrium climate simulations with present-day vs. preindustrial ozone • Greater warming in northern hemisphere (due to more ozone and albedo feedback in Arctic) • Strong cooling in stratosphere: Stratospheric ozone Tropospheric ozone 9. 6 mm Surface Mickley et al. [JGR 2004]

RISE IN OZONE BACKGROUND AT NORTHERN MID-LATITUDES Model values for preindustrial ozone } Observations

RISE IN OZONE BACKGROUND AT NORTHERN MID-LATITUDES Model values for preindustrial ozone } Observations at mountain sites in Europe [Marenco et al. , JGR 1994] Basing radiative forcing estimates on observations rather than models would double the computed ozone forcing to 0. 8 W m-2

LINKING CLIMATE CHANGE AND AIR QUALITY CONCERNS: IMPLICATIONS OF ENHANCED BACKGROUND FOR MEETING AIR

LINKING CLIMATE CHANGE AND AIR QUALITY CONCERNS: IMPLICATIONS OF ENHANCED BACKGROUND FOR MEETING AIR QUALITY STANDARDS Europe AQS (8 -h avg. ) Europe AQS (seasonal) 0 Preindustrial ozone background 20 40 U. S. AQS (8 -h avg. ) 60 80 U. S. AQS (1 -h avg. ) 100 120 ppbv Present-day ozone background at northern midlatitudes Nitrogen oxides (NOx) and methane are the main precursors of background ozone

PROJECTIONS OF GLOBAL NOx EMISSIONS Anthropogenic NOx emissions [IPCC, 2001] 2000 “Optimistic” IPCC scenario:

PROJECTIONS OF GLOBAL NOx EMISSIONS Anthropogenic NOx emissions [IPCC, 2001] 2000 “Optimistic” IPCC scenario: OECD, U. S. m 20%, Asia k 50% 2020 109 atoms N cm-2 s-1

TROPOSPHERIC NO 2 FROM OMI: CONSTRAINT ON NOx SOURCES October 2004 K. Folkert Boersma

TROPOSPHERIC NO 2 FROM OMI: CONSTRAINT ON NOx SOURCES October 2004 K. Folkert Boersma (Harvard)

TROPOSPHERIC NO 2 FROM OMI: ZOOM ON U. S. AND MEXICO During INTEX-B/MILAGRO aircraft

TROPOSPHERIC NO 2 FROM OMI: ZOOM ON U. S. AND MEXICO During INTEX-B/MILAGRO aircraft campaign, March 2006 K. Folkert Boersma (Harvard)

EFFECT OF CLIMATE CHANGE ON OZONE AIR QUALITY Probability of max 8 -h O

EFFECT OF CLIMATE CHANGE ON OZONE AIR QUALITY Probability of max 8 -h O 3 > 84 ppbv vs. daily max. T Ozone exceedances of 90 ppbv, summer 2003 Lin et al. [Atm. Env. 2001] Correlation of high ozone with temperature is driven by (1) Stagnation, (2) Biogenic VOC emissions, (3) Chemistry

EFFECT OF CLIMATE CHANGE ON REGIONAL STAGNATION GISS GCM simulations for 2050 vs. present-day

EFFECT OF CLIMATE CHANGE ON REGIONAL STAGNATION GISS GCM simulations for 2050 vs. present-day climate using pollution tracers with constant emissions 2045 -2052 Thursday night weather map illustrating cyclonic ventilation of the eastern U. S. summer 1995 -2002 Pollution episodes double in duration in 2050 due to decreasing frequency of cyclones ventilating the eastern U. S. Mickley et al. [GRL 2004]

INCREASING BOREAL FOREST FIRES IN PAST DECADE Increasing fire trend: climate change, legacy Radiative

INCREASING BOREAL FOREST FIRES IN PAST DECADE Increasing fire trend: climate change, legacy Radiative impact Area burned (ha) Russia Canada Satellite carbon monoxide (CO) observations Injection to stratosphere (pyroconvection)

RISING MERCURY IN THE BIOSPHERE 3000 -yr record in Swiss bog States with fish

RISING MERCURY IN THE BIOSPHERE 3000 -yr record in Swiss bog States with fish mercury advisories Mercury in polar bear fur up 5 -12 X since 1890 Roos-Baraclough and Shotyk, ES&T 2003 Dietz et al. , ES&T 2006

GEOCHEMICAL CYCLE OF MERCURY (present): emitted to atmosphere as Hg(0), oxidized to Hg(II) and

GEOCHEMICAL CYCLE OF MERCURY (present): emitted to atmosphere as Hg(0), oxidized to Hg(II) and then deposited ATMOSPHERE 5. 4 0. 5 2. 2 1. 5 3. 8 evasion LAND SURFACE 2. 3 SOIL 1000 Natural (rocks, volcanoes) 2. 8 3. 2 evasion wet &dry deposition rivers 0. 2 SURFACE OCEAN 10 0. 6 DEEP OCEAN 280 Anthropogenic (fossil fuels) uplift 0. 5 burial SEDIMENTS Inventories in Gg, fluxes in Gg yr-1 Selin et al. [2006], Strode et al. [2006]

ANTHROPOGENIC EMISSIONS OF MERCURY: shift from N. America/Europe to Asia 1990 Total: 1. 9

ANTHROPOGENIC EMISSIONS OF MERCURY: shift from N. America/Europe to Asia 1990 Total: 1. 9 Gg yr-1 2000 Total: 2. 3 Gg yr-1 Pacyna and Pacyna, 2005

RADICAL BROMINE CHEMISTRY IN TROPOSPHERE GOME satellite instrument observes 0. 52 pptv Br. O

RADICAL BROMINE CHEMISTRY IN TROPOSPHERE GOME satellite instrument observes 0. 52 pptv Br. O in excess of what stratospheric models can explain. Large enhancement seen in Arctic spring Tropospheric Br. O ? due to Arctic BL spring bloom Potentially important consequences for tropospheric ozone, NOx, and mercury

FIRST MASS CONCENTRATION MEASUREMENTS OF ORGANIC CARON (OC) AEROSOLS IN FREE TROPOSPHERE ACE-Asia aircraft

FIRST MASS CONCENTRATION MEASUREMENTS OF ORGANIC CARON (OC) AEROSOLS IN FREE TROPOSPHERE ACE-Asia aircraft data over Japan (April-May 2001) Observed (Huebert) GEOS-Chem (Chung & Seinfeld for SOA) OC/sulfate ratio Observed (Russell) Chung and Seinfeld scheme for secondary organic aerosol (SOA): Observations show 1 -3 mg m-3 background; model too low by factor 10 -100 Heald et al. [2005]

SH NH OXYGENATED VOCs OVER TROPICAL PACIFIC (PEMTROPICS B DATA) Methanol and acetone are

SH NH OXYGENATED VOCs OVER TROPICAL PACIFIC (PEMTROPICS B DATA) Methanol and acetone are ubiquitously present at concentrations that cannot be explained by models. Could there be a missing “organic soup” in the atmosphere? Singh et al. [2001]

HIGH-RESOLUTION EMISSION CONSTRAINTS FROM SATELLITE DATA USING ADJOINTS OF CHEMICAL TRANSPORT MODELS MOPITT daily

HIGH-RESOLUTION EMISSION CONSTRAINTS FROM SATELLITE DATA USING ADJOINTS OF CHEMICAL TRANSPORT MODELS MOPITT daily carbon monoxide (CO) columns (Mar-Apr 2001) Correction factors to a priori emissions A priori knowledge of emissions Fossil fuel Biomass burning Optimal estimation using adjoint of chemical transport model Monika Kopacz, Harvard

OBSERVED CO-CO 2 CORRELATIONS AS CONSTRAINTS FOR CARBON SURFACE FLUX INVERSIONS Correlated CO-CO 2

OBSERVED CO-CO 2 CORRELATIONS AS CONSTRAINTS FOR CARBON SURFACE FLUX INVERSIONS Correlated CO-CO 2 aircraft observations in Asian outflow CO 2, ppbv Combustion: correlated CO-CO 2 source CO, ppbv Observations with error covariances A priori information with error covariances Biosphere: CO 2 -only source/sink OPTIMIZED CO 2 SURFACE FLUXES Inverse model: Combined optimization of CO 2 and CO surface fluxes Suntharalingam et al. [2004] Palmer et al. [2006]

OBSERVING CO 2 FROM SPACE: Orbiting Carbon Observatory (OCO) to be launched in 2008

OBSERVING CO 2 FROM SPACE: Orbiting Carbon Observatory (OCO) to be launched in 2008 OCO will provide powerful constraints on regional carbon fluxes Pressure (h. Pa) Polar-orbiting solar backscatter instrument, measures CO 2 absorption at 1. 61 and 2. 06 mm, O 2 absorption (surface pressure) at 0. 76 mm: global mapping of CO 2 column mixing ratio with 0. 3% precision Averaging kernel (sensitivity)

LOOKING TOWARD THE FUTURE: GEOSTATIONARY AND L 1 MISSIONS GEO L 1 • Continuous

LOOKING TOWARD THE FUTURE: GEOSTATIONARY AND L 1 MISSIONS GEO L 1 • Continuous mapping of tropospheric columns of O 3, aerosols, CO, CH 2 O, NO 2, SO 2 • Continental-scale for GEO, full sunlit disk for L 1 • km-scale resolution