solène turquety – adomoca, 14 novembre 2006 intercomparaison du co mesuré par mopitt en visée...

Solène Turquety – ADOMOCA, 14 Novembre 2006

Intercomparaison du CO mesuré par MOPITT en visée au nadir et par ACE en occultation solaire: complémentarités pour l’étude du transport de la pollution

Solène Turquety, Cathy Clerbaux, Kathy Law, Juliette Hadji-Lazaro Service d'Aéronomie, IPSL, Paris, France.

Pierre-François Coheur, Daniel Hurtmans, Catherine Wespes, Ariane Razavi, Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles.

Didier Hauglustaine, Anne Cozic, Laboratoire des Sciences du Climat et de l’Environnement, IPSL, Gif-sur-Yvette, France

Christopher D. Boone, Peter F. BernathDepartment of Chemistry, University of Waterloo, Waterloo, Canada


IPCC : CO emissions × 3 for East Asia and India between 2000 and 2100 (scenario A2p) NOx emissions × 4

→ Long-range transport has important implication for air quality in downwind regions

→ Reaches a maximum in spring due to active anticyclone and strong westerly winds

→ Transport mainly in the middle troposphere

→ Trans-Pacific transport of pollution in 5-10 days

Richter et al., Nature, 2005

2001

2001

Heald et al., JGR, 2006

East central ChinaHong Kong

X 106

MOPITT

Clerbaux et al., 2006

Importance of the long-range transport of pollution from Asia

Is there information on Asian pollution in the ACE solar occultation measurements in the middle and upper troposphere?


[Clerbaux et al., GRL, 2005]

ACE – Atmospheric Chemistry Experiment

• ACE-SCISAT-1 is a Canadian mission launched on August 13th, 2003

• Primary instrument : ACE-FTS, high resolution IR spectrometer

• Solar occultation : measurement of atmospheric profiles of temperature, pressure and a series of trace gases during sunrise and sunset

• Modified global fit (Levenberg-Marquardt) [Boone et al., 2005]

• Retrieval of key species for tropospheric studies: O3, H2O, H2O2, CO, CH4, C2H6, C2H2, HCN, CH3Cl, SF6, OCS, HNO3, PAN,…

• Vertical resolution ~4km in the middle and upper troposphere

http://www.ace.uwaterloo.ca/mission.htm


Exploiting the complementarities for the study of long range transport

Focus on March-April 2005, a time period with ACE observations at mid-latitudes

1. Intercomparison of CO observations : MOZAIC (in situ), MOPITT (nadir), ACE (solar occultation)

2. Study transport event in March-April 2005 with the global model LMDz-INCA

ACE occultations March–April–May 2005 (+)w/ ATSR hotspots (.)

CO @ 500 hPa (ppbv)

40 100 160

MOPITT @ 500hPa – April 2005


ACE solar occultation measurements vs. MOZAIC in situ data

Comparisons for March-April-May 2004: +/- 2.5° , +/- 1 day MOZAIC + ACE @ 12km (April, 2005)

20050405(26°N, 54°E)ACE

MOZAIC

500

20050504(46°N, 72°W)ACE

MOZAIC

200

20050506(48°N, 15°E)

250

ACE

MOZAIC


Intercomparison of remote sensing CO measurements

Rodgers and Connor, 2003:Apply retrieval characteristics of lower resolution measurement (e.g. MOPITT) to higher resolution measurement (e.g. in situ data, model simulations)

Intercomparison of Level 2 retrievals from different instruments: Need to account for characteristics of the retrievals.

ACE CO retrievalAveraging Kernels[Clerbaux et al., 2005]

High vertical resolution~ 4 km

MOPITT CO retrievalAveraging kernelsLow vertical resolution~ 7 km

lowahighlowlowasmoothed ,, xxAxx Smoothed profile using low resolution measurement characteristics

Low resolutiona priori profile

Low resolutionAveraging kernels

High resolution: original retrieval


MOPITT nadir vs. ACE occultation measurements

MOPITT – April 4, 2005

* ACE occultations- - ss8848.asc

Intercomparison +/- 1° , same day

MOPITTMOPITT a priori profileACE high resolutionACE/MOPITT (smoothed)

• Good agreement : Δ ≤ 18% • MOPITT tends to give larger mixing ratios in the upper troposphere• ACE observations allows complementary measurement of plume vertical structure


DOFs=0.7

Intercomparison +/- 1° , same day

MOPITTMOPITT a priori profileACE high resolutionACE/MOPITT (smoothed)MOZAIC high resolutionMOZAIC/MOPITT (smoothed)ACE+MOZAIC/MOPITT (smoothed)

DOFs ~ 2: information haute troposphère dans MOPITT

DOFs ~ 1: biais ACE / MOPITT dans la haute troposphère, liée à la contribution de la basse troposphère dans MOPITT


LMDz-INCA global model simulation

• Global GCM LMDz (Laboratoire de meteorologie Dynamique, zoom), version 4 (http://www.lmd.jussieu.fr/~lmdz)• Chemistry module INCA (Interaction of Chemistry and Aerosols) NMHC version 2: 85 chemical species; over 300 reactions (Hauglustaine et al., 2005, http://www-lsceinca.cea.fr/)• Simulation using the nudged version, driven by ECMWF meteorological fields • Resolution 3.75° longitude x 2.5° latitude, 19 vertical levels (surface – 3hPa)• Anthropogenic emissions from EDGAR v.2; biogenic emissions from GEIA• Biomass burning emissions (1st approximation) : Climatology (average 1995-2003 from Van der Werf et al.) redistributed according to MODIS fire detection for 2005 (monthly emissions)

INCA x MOPITT AK

MOPITT CO @ 700hPa – April 2005 SCIAMACHY tropospheric NO2 (KNMI) – April 2005

INCA tropospheric NO2

Underestimate anthropogenic emissions (Asia) ; Need more accurate biomass burning


Long-range transport from Asia in March-April 2005

INCA x MOPITT AK

MOPITT @ 500hPa – 20050327-20050404

20050329 20050330

20050331 20050401

20050402 20050403

ACE observations

ECMWF winds


Comparison of CO from ACE and the LMDz-INCA model

INCA @ 400 hPa20050327-20050404

Average INCA distribution for the days of ACE comparisons


120° 150° 180° -150° -120°120° 150° 180° -150° -120°

ACE occultation

tropopause



120° 150° 180° -150° -120°120° 150° 180° -150° -120°

ACE occultation



INCA @ 400 hPa20050327-20050404

Average INCA distribution for the days of ACE comparisons

Comparison of O3 from ACE and the LMDz-INCA model


120° 150° 180° -150° -120°

ACE occultation

120° 150° 180° -150° -120°

Comparison of O3 from ACE and the LMDz-INCA model


120° 150° 180° -150° -120°

ACE occultation

Stratospheric intrusion?

O3 net production

Fraction of stratospheric O3

CO

NOx


ACE occultation

120° 150° 180° -150° -120°

Stratospheric intrusion?

O3 net production

Fraction of stratospheric O3

CO

NOx


Conclusions

Future work

• Comparisons to TES/Aura observations

• Improve emissions in the LMDz-INCA simulation using results from inverse modeling analyses

• Analysis of ozone production during the long range transport

• Assimilation: complementary constraint from different observation geometry? Vertical resolution vs. number of observations intergrated?

• ACE occultation measurements provide information on a series of trace gases with good vertical resolution in the upper troposphere

• CO measurements consistent with MOZAIC in situ and MOPITT satellite measurements

• Combined analysis with nadir measurements (better spatio-temporal resolution, lower vertical resolution) and global model provides information on the global context and transport pathways

• ACE gives detailed information on the chemical composition of air masses in the upper troposphere

• Interesting tool for the study of the long range transport

solène turquety – adomoca, 14 novembre 2006 intercomparaison du co mesuré par mopitt en visée...

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