Transcript Document

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. Bernath
Department of Chemistry, University of Waterloo, Waterloo, Canada
Solène Turquety – ADOMOCA, 14 Novembre 2006
Importance of the long-range transport of pollution from Asia
X 106
East central China
Hong Kong
2001
2001
MOPITT
Clerbaux et al., 2006
Richter et al., Nature, 2005
Heald et al., JGR, 2006
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
Is there information on Asian pollution in the ACE solar occultation measurements
in the middle and upper troposphere?
Solène Turquety – ADOMOCA, 14 Novembre 2006
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
[Clerbaux et al., GRL, 2005]
Solène Turquety – ADOMOCA, 14 Novembre 2006
Exploiting the complementarities for the study of long range transport
ACE occultations March–April–May 2005 (+)
w/ ATSR hotspots (.)
MOPITT @ 500hPa – April 2005
CO @ 500 hPa (ppbv)
40
100
160
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
Solène Turquety – ADOMOCA, 14 Novembre 2006
ACE solar occultation measurements vs. MOZAIC in situ data
Comparisons for March-April-May 2004:
+/- 2.5° , +/- 1 day
ACE
MOZAIC + ACE @ 12km (April, 2005)
20050405
(26°N, 54°E)
MOZAIC
500
ACE
20050504
(46°N, 72°W)
ACE
20050506
(48°N, 15°E)
MOZAIC
MOZAIC
200
250
Solène Turquety – ADOMOCA, 14 Novembre 2006
Intercomparison of remote sensing CO measurements
Intercomparison of Level 2 retrievals from different instruments:
Need to account for characteristics of the retrievals.
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)
xsmoothed  xa,low  Alow xhigh  xa,low 
Smoothed profile using low
resolution measurement
characteristics
ACE CO retrieval
Averaging Kernels
[Clerbaux et al., 2005]
High vertical resolution
~ 4 km
Low resolution Low resolution
a priori profile Averaging kernels
High resolution: original retrieval
MOPITT CO retrieval
Averaging kernels
Low vertical resolution
~ 7 km
Solène Turquety – ADOMOCA, 14 Novembre 2006
MOPITT nadir vs. ACE occultation measurements
MOPITT – April 4, 2005
* ACE occultations
- - ss8848.asc
Intercomparison +/- 1° , same day
MOPITT
MOPITT a priori profile
ACE high resolution
ACE/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
Solène Turquety – ADOMOCA, 14 Novembre 2006
Intercomparison +/- 1° , same day
MOPITT
MOPITT a priori profile
ACE high resolution
ACE/MOPITT (smoothed)
MOZAIC high resolution
MOZAIC/MOPITT (smoothed)
ACE+MOZAIC/MOPITT (smoothed)
DOFs=0.7
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
Solène Turquety – ADOMOCA, 14 Novembre 2006
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)
MOPITT CO @ 700hPa – April 2005
INCA x MOPITT AK
SCIAMACHY tropospheric NO2 (KNMI) – April 2005
INCA tropospheric NO2
Underestimate anthropogenic emissions (Asia) ; Need
more
accurate
biomass14
burning
Solène
Turquety
– ADOMOCA,
Novembre 2006
Long-range transport from Asia in March-April 2005
20050329
20050330
20050331
20050401
20050402
20050403
MOPITT @ 500hPa – 20050327-20050404
INCA x MOPITT AK
ECMWF winds
ACE observations
Solène Turquety – ADOMOCA, 14 Novembre 2006
Comparison of CO from ACE and the LMDz-INCA model
INCA @ 400 hPa
20050327-20050404
Average INCA
distribution for
the days of ACE
comparisons
Solène Turquety – ADOMOCA, 14 Novembre 2006
Comparison of CO from ACE and the LMDz-INCA model
120°
150°
180°
-150°
-120°
120°
150°
180°
-150°
-120°
ACE occultation
tropopause
Solène Turquety – ADOMOCA, 14 Novembre 2006
Comparison of CO from ACE and the LMDz-INCA model
120°
150°
180°
-150°
-120°
120°
150°
180°
-150°
-120°
ACE occultation
Solène Turquety – ADOMOCA, 14 Novembre 2006
Comparison of O3 from ACE and the LMDz-INCA model
INCA @ 400 hPa
20050327-20050404
Average INCA
distribution for
the days of ACE
comparisons
Solène Turquety – ADOMOCA, 14 Novembre 2006
Comparison of O3 from ACE and the LMDz-INCA model
120°
150°
180°
-150°
-120°
120°
150°
180°
-150°
-120°
ACE occultation
Solène Turquety – ADOMOCA, 14 Novembre 2006
CO
120°
150°
180°
-150°
-120°
NOx
ACE occultation
O3 net production
Stratospheric intrusion?
Fraction of stratospheric O3
Solène Turquety – ADOMOCA, 14 Novembre 2006
CO
120°
150°
180°
-150°
-120°
NOx
ACE occultation
O3 net production
Stratospheric intrusion?
Fraction of stratospheric O3
Solène Turquety – ADOMOCA, 14 Novembre 2006
Conclusions
• 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
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?
Solène Turquety – ADOMOCA, 14 Novembre 2006