BRIDGING THE SCALES IN ATMOSPHERIC CHEMISTRY:BRIDGING THE SCALES IN ATMOSPHERIC CHEMISTRY:LOCAL TO GLOBALLOCAL TO GLOBAL

Daniel J. Jacob

with Jenny A. Fisher, Monika Kopacz, Lin Zhang, Tzung-May Fu, Easan E. Drury, Eric M. Leibensperger, Shiliang Wu, Loretta J. Mickley, Chris D. Holmes

and support from NASA, EPRI, NSF, EPA

SCALES OF ATMOSPHERIC CHEMISTRY PROBLEMSSCALES OF ATMOSPHERIC CHEMISTRY PROBLEMS

LOCAL < 100 km

REGIONAL100-1000 km

GLOBAL > 1000 km

Urban smog

Point source

Disasters Visibility

Regional smog

Acid rain

Ozonelayer

Climate

Biogeochemical cycles

Annecy

SCALE SEPARATION AND INTERACTIONSSCALE SEPARATION AND INTERACTIONS

BL turbulence,sea breezes…

mesoscale synoptic scale

Deepconvection

subsidence

LOCAL REGIONAL

planetary waves,general circulation…

GLOBAL

OCEANSLAND

chem ~ 0.1-10 d

chem > 10 d

fronts,monsoons…

chem < 1 d

Non-linear chemical & aerosol evolution

Dynamic/interactive boundary conditions

NASA/ARCTAS AIRCRAFT CAMPAIGN (April+July 2008)NASA/ARCTAS AIRCRAFT CAMPAIGN (April+July 2008)Objective: better understand changes in Arctic pollution and climate

FairbanksCold Lake

Yellowknife

Aura

Calipso Aqua

A-train

Focus on mid-latitudes pollution, Arctic haze (spring), boreal forest fires (summer)

Asia N. America

Fire plumes

Fire plumes

Mid-latitudes ArcticDeposition

Air quality

Arcticclimateforcing

Eu

rop

e

INTEGRATING SATELLITE, AIRCRAFT, AND MODEL INFORMATIONINTEGRATING SATELLITE, AIRCRAFT, AND MODEL INFORMATIONTO BETTER UNDERSTAND SOURCES OF ARCTIC POLLUTIONTO BETTER UNDERSTAND SOURCES OF ARCTIC POLLUTION

J.A. Fisher [Harvard], G. Diskin [LaRC], J. Warner [UMBC]

Asian plume transported to Arctic in warm conveyor belt on April 16, 2008

Aircraft GEOS-Chem

AIRS GEOS-Chem

Aircraft CO data at 4-6 km (500 hPa)compared to GEOS-Chem chemical transport model

AIRS satellite data for CO at 500 hPacompared to GEOS-Chem

with averaging kernels

Satellites provide global continuousobservations;Aircraft provide satellite validation, complementary species, local process information;Models provide link between aircraft and satellite, platform for understanding and prediction

SATELLITES AND MODELS ARE INSEPARABLESATELLITES AND MODELS ARE INSEPARABLE

336-356 nm backscatteredradiance spectrummeasured from space

Formaldehyde columnConcentrations(OMI, JJA 2006)

Isoprene emission fluxes

Radiative transfer model& its inverse

Chemical transport model& its inverse

…must be viewed with in situ data as a unified observing system

Millet et al. [JGR 2008]

a prioriinfo

relationshipsto processes

evaluation

aircraft

Surface sites

Formaldehydeabsorption lines

Aircraft: Aerosol chemistrySize distributionOptical properties

INTEGRATING SATELLITE, AIRCRAFT, AND GROUND-BASED AEROSOL DATAINTEGRATING SATELLITE, AIRCRAFT, AND GROUND-BASED AEROSOL DATATO CONSTRAIN U.S. AEROSOL SOURCES DURING ICARTT (Jul-Aug ’04)TO CONSTRAIN U.S. AEROSOL SOURCES DURING ICARTT (Jul-Aug ’04)

surface networks: IMPROVE (aerosol chemistry), AERONET (AOD)

MODISTOA reflectance

GEOS-Chemchemicaltransportmodel

MODIS c5 operational .productSynthetic top-of-atmosphere (TOA)

reflectance

backscatteredradiation

Optimize retrieval of aerosol optical depth (AOD) and surface concentrations

GEOS-Chem AODs

AERONET in circles

MODIS AODs at 0.47 m

ObservedModelSulfateOC dust

0.1 1 m

Size distribution Difference between MODIS and GEOS-Chem AODs;constraint on aerosol sources

Drury et al. (in prep.)

priorinfo

INTEX-B AIRCRAFT CAMPAIGN OVER NORTHEAST PACIFIC (2006)

CO columns

TES GEOS-Chem AIRS

Zhang et al. [ACP, in press]

aircrafttrack

A

B

AIRS and TES satellite observations of transpacific plume

TES observes ozone as well as CO; observed ozone-correlation indicates ozone production over Pacific but signal is noisy (observations are sparse)

TRANSPACIFIC PLUME OBSERVED BY INTEX-B AIRCRAFT (May 9, 2006)

B-south branch

HNO3NO

O3CO

Solid: observationsDash: GEOS-Chem

A-north branch

PAN

COO3

PAN

Backward (7 d) and forward (3 d) trajectories

for points A and B

• Ozone is produced in the southern branch following subsidence and decomposition of PAN to NOx

• Most of this ozone circles around the Pacific High and eventually dies during transport to western equatorial Pacific; only a small fraction reaches the western U.S.

A

B

graveyard ofAsian pollution

Zhang et al. [ACP, in press]

CONSEQUENCES FOR U.S. SURFACE OZONECONSEQUENCES FOR U.S. SURFACE OZONE

GEOS-Chem Asian pollution:9 ± 2

Observed: 54 ± 10

GEOS-Chem: 53 ± 8

U.S. surface ozone during INTEX-B campaign (April-May 2006)

Observations (Dan Jaffe, UW) and GEOS-Chemat Mt. Batchelor, Oregon (2,700 m)

2000-2006 doubling of Asian NOx emissions has increased U.S. surface ozone by 1-3 ppbv in the West

Zhang et al. , ACP, in press

Mean Asian surface pollution enhancement (GEOS-Chem)

Apr 17 Apr 23 Apr 29 May 5 May 11 ppb

INTERCONTINENTAL SOURCE ATTRIBUTION OF OZONE INTERCONTINENTAL SOURCE ATTRIBUTION OF OZONE USING MODEL ADJOINTSUSING MODEL ADJOINTS

GEOS-Chem adjoint simulation for INTEX- B period (Apr-May 2006)

Contribution of ozone production regions to ozone concentration at Mt. Batchelor Observatory

23% 21%17%

6%6%

Mean East Asian pollution enhancement of 9.2 ppb at MBO includes 5.6 ppb from China and 3.6 ppb from Japan+Korea

Zhang et al. [in prep.]

ORIGIN OF HIGH ORGANIC AEROSOL CONCENTRATIONSORIGIN OF HIGH ORGANIC AEROSOL CONCENTRATIONS IN FREE TROPOSPHERE? IN FREE TROPOSPHERE?

ACE-Asia aircraft data over Japan (April-May 2001)

Observed (Huebert)GEOS-Chem model

Observed (Russell)

Heald et al. [GRL 2005]

Observations show 1-3 g m-3 background; model including standard scheme for secondary organic aerosol (SOA) is too low by factor 10-100

,T OCVOC SOG SOA

ICARTT AIRCRAFT DATA OVER EASTERN U.S. ICARTT AIRCRAFT DATA OVER EASTERN U.S. (Jul-Aug 2004)(Jul-Aug 2004)

Mean vertical profile of water-soluble organic carbon (WSOC) aerosol

Observed (Weber)

Model w/ dicarbonyl SOA addedModel w/ standard SOA

Correlation with other variables measuredfrom aircraft (grey = obs, colors = model)

Fu et al. [AE, submitted]

includesSOA fromirreversiblecloud uptake of glyoxal & methylglyoxal

SENSITIVITY OF SURFACE AIR QUALITY SENSITIVITY OF SURFACE AIR QUALITY TO METEOROLOGICAL VARIABLESTO METEOROLOGICAL VARIABLES

Insights into the effect of climate change on air quality

Ozone PM (aerosol)

Stagnation

Temperature

Mixing depth

Precipitation

Cloud cover

Humidity

Effect of climate change

=

=?

?=?

? (relative)

Jacob and Winner, AE 2008

IMPORTANCE OF MID-LATITUDES CYCLONES IMPORTANCE OF MID-LATITUDES CYCLONES IN AIR POLLUTION METEOROLOGYIN AIR POLLUTION METEOROLOGY

Clean air sweepsbehind cold front

Cold fronts from mid-latitude cyclones are the principal ventilation processfor U.S. Midwest/Northeast, western Europe, China

IPCC shows decrease + N shift of cyclones from 21st-century climate change;already seen in 1950-2000 climatological data

CORRELATIONS AND TRENDSCORRELATIONS AND TRENDSOF POLLUTION EPISODES AND CYCLONES IN NORTHEAST U.S.OF POLLUTION EPISODES AND CYCLONES IN NORTHEAST U.S.

# pollution episode days (O3>80 ppb) and # cyclones tracking across SE Canadain summer 1980-2006 observations

Cyclone track

• Strong correlation; cyclone frequency is predictor of pollution episode frequency

• 1980-2006 decrease in cyclone frequency would imply a corresponding degradation of air quality if emissions had remained constant

• Expected # of 80 ppb exceedance days in Northeast dropped from 30 in 1980 to 10 in 2006, but would have dropped to zero by 2001 in absence of cyclone trend!

Leibensperger et al. [ACP, submittted]

# cyclones# episodes

ENSEMBLE MODEL ANALYSIS OF CLIMATE CHANGE EFFECT ENSEMBLE MODEL ANALYSIS OF CLIMATE CHANGE EFFECT ON OZONE AIR QUALITY IN THE U.S.ON OZONE AIR QUALITY IN THE U.S.

MDA8

-9-8-7-6-5-4-3-2-1012345

NE MW CA TX SE

Harvard.A1B CMU.A2 PGR.B1 NERL.A1B WSU.A2 PGR.A1Fi

Northeast Midwest California Texas Southeast

• Models show consistent projection of ozone increase in Northeast/Midwest- likely reflects decrease in mid-latitude cyclone frequency

• …but large disagreements in Southeast - due in part to isoprene chemistry

isopreneNOx

isoprenenitrates

????

How will isoprene emissions actually respond to climate change? Increase in CO2, land cover change…

Weaver et al. [BAMS, submitted]

Results from six coupled GCM-CTM simulations

2000-2050 change of 8-h daily max ozone in summer, keeping anthropogenic emissions constantppb

REGIONAL CLIMATE SENSITIVITY TO ANTHROPOGENIC AEROSOLSREGIONAL CLIMATE SENSITIVITY TO ANTHROPOGENIC AEROSOLS

Aerosol optical depths, at 550 nm

DJF surface temperatures

15-year GISS GCM simulation with zeroed U.S. aerosols

vs. control present-day simulation

Large warming over eastern U.S. (>1o C), cooling in Arctic;

teleconnection over East Asia

Mickley et al. [in prep.]

Sulfur emission controls will enhance warming – but by how much?

Atmospheric componentof cycle:

Hg(0)

Hg(II)OH, O3, Br

aq, h

deposition

dry wetdry

GLOBAL BIOGEOCHEMICAL CYCLING OF MERCURYGLOBAL BIOGEOCHEMICAL CYCLING OF MERCURY

? ??? ?

PRESENT-DAYInventories in MgFlows in Mg a-1

5600

1,150,000 7000

Selin et al. [GBC 2008]

DIURNAL CYCLE OF REACTIVE GASEOUS MERCURY (RGM) DIURNAL CYCLE OF REACTIVE GASEOUS MERCURY (RGM) IN MARINE BOUNDARY LAYERIN MARINE BOUNDARY LAYER

Early a.m. rise, midday peak suggests Br chemistry, deposition via sea salt uptake

Hg(0) HgBrBr

T

Br, OHHgBrX

sea-salt aerosol

HgCl32-, HgCl4

2-

deposition

MBL budgets

Model predicts that ~80% of Hg(II) in MBL should be in sea salt:

Holmes et al. [in prep.]

Observed [Laurier et al., 2003]Model Hg(0)+BrModel Hg(0)+OH

Subtropical Pacific cruise data

SATELLITES:LEO, Geo, L1 orbits, lunar

OBSERVING SYSTEM FOR ATMOSPHERIC COMPOSITION IN 2025OBSERVING SYSTEM FOR ATMOSPHERIC COMPOSITION IN 2025

SURFACE SITES, SHIPSLong-term trendsSurface fluxesProcess information

ROBOTIC AIRCRAFT

Process informationSurface fluxes

Global/regional continuous mappingTop-down constraints on emissionsStratospheric monitoringSun-Earth interactions

ADAPTIVE EARTHSYSTEM MODELSData assimilation, inversionUnderstanding & prediction