CONTINENTAL OUTFLOW AND INTERCONTINENTAL CONTINENTAL OUTFLOW AND INTERCONTINENTAL TRANSPORT AT NORTHERN MIDLATITUDES TRANSPORT AT NORTHERN MIDLATITUDES

(and a few UT/LS topics)(and a few UT/LS topics)

Daniel J. Jacob

Atmospheric Chemistry Modeling Group

Harvard University

ARE ATMOSPHERIC OBSERVATIONS OF ACETONEARE ATMOSPHERIC OBSERVATIONS OF ACETONECONSISTENT WITH CURRENT UNDERSTANDINGCONSISTENT WITH CURRENT UNDERSTANDING

OF SOURCES AND SINKS?OF SOURCES AND SINKS?

TRACE-A

SONEX

ABLE-3B PEM

-WB

PEM-TB

Surface sites

GLOBAL BUDGET OF ATMOSPHERIC ACETONEGLOBAL BUDGET OF ATMOSPHERIC ACETONE

Singh et al. Jacob et al. [2002]

[2000] (a priori) (a posteriori)

SOURCES (Tg yr-1) 56 (37-80) 78 (49-105) 95 (80-110)

Terrestrial vegetation 15 (10-20) 26 (0-52) 33 (24-42)

Plant decay 6 (4-8) 9 (0-18) 2 (-3-7)

Biomass burning 5 (3-10) 3 (2-5) 5 (3-7)

Industry 2 (1-3) 1 (1-2) 1 (1-2)

Oceans 0 10 (0-20) 27 (21-33)

Oxidation of isoalkanes 17 (12-24) 20 (10-30) 21 (16-26)

Oxidation of terpenes, MBO 11 (7-15) 9 (3-15) 7 (3-11)

SINKS (Tg yr-1) 56 (37-80) 78 95

Photolysis 36 (24-51) 44 46

Oxidation by OH 13 (9-19) 25 27

Deposition to land 7 (4-10) 9 9

Uptake by ocean 0 0 14

LIFETIME 16 days 20 days 15 days

OCEANIC SIGNATURE OCEANIC SIGNATURE IN ATMOSPHERIC ACETONE OBSERVATIONSIN ATMOSPHERIC ACETONE OBSERVATIONS

Low winter values over Europe imply ocean sink

southern Norway[Solberg et al., 1996]

High values over South Pacific imply large ocean source

South Pacific[Singh et al., 2001]

a priori sources/sinks; 2 = 1.3 a posteriori sources/sinks(including “microbial” ocean sink,photochemical ocean source); 2 = 0.39

SURFACE AIR ACETONE CONCENTRATIONSSURFACE AIR ACETONE CONCENTRATIONSIN IN A POSTERIORIA POSTERIORI SIMULATION SIMULATION

METHYL IODIDE: TRACER OF MARINE CONVECTION IN METHYL IODIDE: TRACER OF MARINE CONVECTION IN GLOBAL ATMOSPHERIC MODELSGLOBAL ATMOSPHERIC MODELS

Loss by photolysis (~4 days), relatively uniform ocean Loss by photolysis (~4 days), relatively uniform ocean source, large aircraft data base [D.R. Blake, UCI]source, large aircraft data base [D.R. Blake, UCI]

Simple modelfor ocean source

Observations

Model(GEOS-CHEM)

Define Marine Convection Index (MCI) as ratio of upper tropospheric (8-12 km)to lower tropospheric (0-2.5 km) CH3I concentrations

• MCI over Pacific ranges from 0.11 (Easter Island dry season) to 0.40 (observations over tropical Pacific • GEOS-CHEM reproduces observed MCI with little global bias (+11%) but poor correlation (r2 = 0.15, n=11)

Bell et al. [2002]

MCI: 0.40 (obs) 0.22 (mod)

MCI: 0.16 (obs) 0.14 (mod)

SURFACE OZONE BACKGROUND IN THE U.S. SURFACE OZONE BACKGROUND IN THE U.S. IMPORTED FROM OUTSIDE IS A SIZABLE INCREMENT IMPORTED FROM OUTSIDE IS A SIZABLE INCREMENT

TOWARDS VIOLATION OF U.S. AIR QUALITY STANDARDSTOWARDS VIOLATION OF U.S. AIR QUALITY STANDARDS(even more so in Europe!)(even more so in Europe!)

0 20 40 60 80 100 120 ppbv

Europe(seasonal)

U.S.(8-h avg.)

U.S.(1-h avg.)

preindustrial presentbackground

Europe (8-h avg.)

OZONE BACKGROUND OVER U.S. IS GENERALLY DEPLETED OZONE BACKGROUND OVER U.S. IS GENERALLY DEPLETED DURING REGIONAL POLLUTION EPISODESDURING REGIONAL POLLUTION EPISODES

due to deposition and chemical loss under stagnant conditionsdue to deposition and chemical loss under stagnant conditions

Background(clean conditions)

O3 vs. (NOy-NOx) At Harvard Forest,

Massachusetts

Background(pollution episodes)

Observed (J.W. Munger)model (GEOS-CHEM)model background

Pollution coordinateFiore et al. [2002]

RANGE OF ASIAN/EUROPEAN POLLUTION RANGE OF ASIAN/EUROPEAN POLLUTION SURFACE OZONE ENHANCEMENTS OVER THE U.S. IN SUMMERSURFACE OZONE ENHANCEMENTS OVER THE U.S. IN SUMMER

asas determined from a simulation with these emissions shut offdetermined from a simulation with these emissions shut off

Max Asian/European pollution enhancements(up to 14 ppbv) occur at intermediate ozone levels (50-70 ppbv)

MAJOR CONCERNIF U.S. OZONE STANDARDWERE TO DECREASE!

Fiore et al. [2002]

tropical air

Subsidence of Asian pollution+ local production

stagnation

U.S. standardEuropean standards

NORTH AMERICAN OZONE OUTFLOW IN SURFACE AIR NORTH AMERICAN OZONE OUTFLOW IN SURFACE AIR (GEOS-CHEM model results for 1997)(GEOS-CHEM model results for 1997)

Li et al. [2002]

APRIL

JULY

LL

HH

HH

LL

OZONE DATA AT MACE HEAD, IRELANDOZONE DATA AT MACE HEAD, IRELAND

Observed[Simmonds]

GEOS-CHEMmodel

N.America pollutionevents in model

Time series, Mar-Aug 1997

Model vs. observedstats, 1993-1997

Li et al. [2002]

FORECASTING TRANSATLANTIC TRANSPORT OF FORECASTING TRANSATLANTIC TRANSPORT OF NORTH AMERICAN POLLUTION TO EUROPE WITH THENORTH AMERICAN POLLUTION TO EUROPE WITH THE

NORTH ATLANTIC OSCILLATION (NAO) INDEXNORTH ATLANTIC OSCILLATION (NAO) INDEX

NAO IndexNorth American ozone pollution enhancementAt Mace Head, Ireland (GEOS-CHEM model)

r = 0.57

NAO index = normalized surface P anomaly between Iceland and Azores

Li et al.[2002]

Greenhouse warming NAO index shift change in transatlantic transport of pollution

EFFECT OF NORTH AMERICAN SOURCESEFFECT OF NORTH AMERICAN SOURCESON VIOLATIONS OF EUROPEAN AIR QUALITY ON VIOLATIONS OF EUROPEAN AIR QUALITY

STANDARD (55 ppbv, 8-h average)STANDARD (55 ppbv, 8-h average)GEOS-CHEM modelresults, summer 1997

Number of violation days(out of 92)

# of violation days thatwould not have beenin absence of N.American emissions

Li et al. [2002]

Enhancements in Asian surface ozone due to European Enhancements in Asian surface ozone due to European anthropogenic emissions (GEOS-CHEM, 1996)anthropogenic emissions (GEOS-CHEM, 1996)

Liu et al.[2002]

GLOBAL MODEL ANALYSIS OF OZONESONDE GLOBAL MODEL ANALYSIS OF OZONESONDE OBSERVATIONS ALONG THE PACIFIC RIM (1993-1997)OBSERVATIONS ALONG THE PACIFIC RIM (1993-1997)

observationsGEOS-CHEM model

High UT variability at Hong Kong in winter-spring reflects alternance of tropical and stratospheric influences

Liu et al. [2002]

Spring enhancementfrom SE Asian biomass burning

Hong Kong, 1996

300-120 hPa

700-300 hPa

850-700 hPa

ALTERNANCE OF TROPICAL AND STRATOSPHERIC ALTERNANCE OF TROPICAL AND STRATOSPHERIC INFLUENCES IN WINTER UT OVER HONG KONG:INFLUENCES IN WINTER UT OVER HONG KONG:

comparison of Dec 24, 1996 and Jan 6, 1997comparison of Dec 24, 1996 and Jan 6, 1997

ObservedGEOS-CHEM

Sonde and model profiles

Model ozone concentrations and fluxes, 200 hPa

Stratospheric ozone tracer at longitude of Hong Kong

Liu et al. [2002]

200 hPa ozone fluxes across Pacific Rim (GEOS-CHEM, 1996) 200 hPa ozone fluxes across Pacific Rim (GEOS-CHEM, 1996) • Tropical and midlatitude influences• Easterly circulation away from Pacific in summer

Liu et al.[2002]

SUMMER UT OZONE POLLUTION EVENT OVER HONG KONGSUMMER UT OZONE POLLUTION EVENT OVER HONG KONGAugust 21, 1996August 21, 1996

ObservedGEOS-CHEM

Asianpollution

Sonde and model profiles

Model enhancement of ozone concentrationsand fluxes due to Asian anthropogenic sources

Liu et al. [2002]

WHAT OBSERVATIONS AND MODELS ARE NEEDEDWHAT OBSERVATIONS AND MODELS ARE NEEDEDTO BETTER QUANTIFY INTERCONTINENTAL TRANSPORT?TO BETTER QUANTIFY INTERCONTINENTAL TRANSPORT?

3-D CHEMICAL TRACER MODELS

INTERCONTINENTAL TRANSPORT:INTERCONTINENTAL TRANSPORT:CONCENTRATIONS AND FLUXESCONCENTRATIONS AND FLUXES

SATELLITE OBSERVATIONSGlobal and continuous but few species, low resolution

AIRCRAFT OBSERVATIONSHigh resolution, targeted flights

provide critical snapshots for model testing

SURFACE OBSERVATIONShigh resolution but spatially limited

Source/sinkinventories

Assimilated meteorological

data

Chemical and aerosolprocesses

TRACE-P MISSIONTRACE-P MISSION(Mar-Apr 2001)(Mar-Apr 2001)

Emissions-Fossil fuel-Biomass burning-Biosphere, dust

Long-range transport fromEurope, N. America, Africa

ASIA PACIFIC

P-3

Satellite datain near-real time:MOPITTTOMSSEAWIFSAVHRRLIS

DC-8

3D chemical model forecasts: - ECHAM - GEOS-CHEM - Iowa/Kyushu - Meso-NH -LaRC/U. Wisconsin

FLIGHTPLANNING

Boundary layerchemical/aerosolprocessing

ASIANOUTFLOW

Stratosphericintrusions

PACIFIC

GOME daily data of NOGOME daily data of NO22 and HCHO and HCHO

tropospheric columns during TRACE-P (3/15 - )tropospheric columns during TRACE-P (3/15 - )

Randall Martin

Mean slant NO2 column, 3/16-4/15 Slant HCHO column, singleorbit on 3/27

Thomas Kurosu/Kelly Chance

CARBON MONOXIDE CONCENTRATIONSCARBON MONOXIDE CONCENTRATIONSMEASURED IN TRACE-PMEASURED IN TRACE-P

40

30

20

10

160150140130120110100

14

12

10

8

6

4

2

Perchlorethylene (pptv)

>15

HONG KONG

TOKYO

<1

Distribution of Perchlorethylene (C2Cl4) Measured During TRACE P

Don Blake, UCI

Symbol size 1/altitude

CC22ClCl44 CONCENTRATIONS MEASURED IN TRACE-P CONCENTRATIONS MEASURED IN TRACE-P

INVERSE ANALYSIS OF CO SET UP FOR TRACE-PINVERSE ANALYSIS OF CO SET UP FOR TRACE-Pa priori a priori Asian emissions appear low but not outrageously soAsian emissions appear low but not outrageously so

Paul Palmer,Harvard

PRELIMINARY GLOBAL (GEOS-CHEM) 3-D MODEL PRELIMINARY GLOBAL (GEOS-CHEM) 3-D MODEL ANALYSIS OF TRACE-P OBSERVATIONS ANALYSIS OF TRACE-P OBSERVATIONS

Mat Evans,Harvard

GLOBAL MODEL ANALYSIS OF TRACE-P OBSERVATIONS: GLOBAL MODEL ANALYSIS OF TRACE-P OBSERVATIONS: SENSITIVITY TO SOURCESSENSITIVITY TO SOURCES

Mat Evans, Harvard

Median model/observed Median model/observed

OZONE CO

Median model/observed

• To quantify the North American import and export of

(1) atmospheric oxidants and their precursors, (2) aerosols and their

precursors, (3) long-lived greenhouse gases

• To relate this import/export to surface sources/sinks and to

continental boundary layer chemistry

INTERCONTINENTAL TRANSPORT EXPERIMENT – INTERCONTINENTAL TRANSPORT EXPERIMENT – NORTH AMERICA (INTEX-NA)NORTH AMERICA (INTEX-NA)

OBJECTIVES:

TWO PHASES:• Summer 2004:

- active photochemistry, biosphere- aerosol radiative forcing- carbon uptake

• Spring 2006:- maximum Asian inflow- contrast with summer

TWO AIRCRAFT: NASA DC-8 and P-3

The next NASA Global Tropospheric Experiment (GTE) mission

DR

RL BG

BR

AZWL

DC-8

P-3B

HI

NO

Ozonesonde sites

INTEX NOMINAL FLIGHT TRACKS FOR PHASE A (SUMMER)INTEX NOMINAL FLIGHT TRACKS FOR PHASE A (SUMMER)

INTEX-NA HAS LINKAGES WITH A NUMBER OF INTEX-NA HAS LINKAGES WITH A NUMBER OF ATMOSPHERIC PROGRAMSATMOSPHERIC PROGRAMS

• In situ– North American Carbon Program (2002-)

– NOAA Northeast U.S. Study (2004)

– European UT/LS program (-2005) - LET’S TALK!!!

– Asian APARE program (ongoing)

• Satellites– Terra [MOPITT] (1999-)

– Envisat [SCIAMACHY, MIPAS] (2002-)

– NMP/GIFTS (2004-)

– Aura [TES, OMI, HRDLS, TES] (2004-)

• Modeling– EPA OAQPS/ORD climate change/air quality initiative (2001-2010)