BRIDGING THE SCALES IN ATMOSPHERIC CHEMISTRY: LOCAL TO GLOBAL Daniel J. Jacob with Jenny A. Fisher,...
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Transcript of BRIDGING THE SCALES IN ATMOSPHERIC CHEMISTRY: LOCAL TO GLOBAL Daniel J. Jacob with Jenny A. Fisher,...
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