Monitoring of atmospheric composition using the thermal infrared IASI/MetOp sounder Cathy Clerbaux, Solène Turquety, Juliette Hadji-Lazaro, Maya George, Anne Boynard Matthieu Pommier Service d'aéronomie / CNRS, IPSL, Université Paris 6 Paris, France Pierre-François Coheur, Daniel Hurtmans Catherine Wespes, Ariane Razavi, Hervé Herbin Spectroscopie de l Atmosphère, Chimie Quantique et Photophysique, Université Libre de Bruxelles, Belgique + 2 oral presentations + 6 posters
Outline What is the added value of IASI for tropospheric chemistry? Trace gas retrievals from level 1C radiance spectra - Near-real time global distributions of O 3 and CO - Profile retrievals for chemistry species : O 3, CO, SO 2 Conclusions and perspectives
What is the added value of IASI for tropospheric chemistry? (1/3) + IASI provides global Earth coverage twice daily, day AND NIGHT IMG/ADEOS 24h coverage IASI/MetOp 24h coverage # spectra 1.2M 1.M 8.k 27117 27122 27127 27111 27116
What is the added value of IASI for tropospheric chemistry? (2/3) + Broad spectral coverage (645-276 cm -1 without gaps) simultaneous sounding of many trace gases SA/CNRS ULB Radiance (W / cm 2 sr cm -1 ) 1.4x1-5 1.2x1-5 1.x1-5 8.x1-6 6.x1-6 4.x1-6 2.x1-6 CO 2 HNO 3 CFC11, CFC12 O CO 3 CO 2, N 2 O Ts=275 K N 2 O, CH 4 H 16 2 O, HOD HOD H 16 2 O CH 4 H 18 2 O. 8 1 12 14 16 18 2 22 24 26 Wavenumber (cm -1 ) + Thermal + reflected solar radiation during daytime possible improvements on the retrieval performances for CH 4 and HDO
What is the added value of IASI for tropospheric chemistry? (3/3) 1.x1-5 IMG Radiance (W / cm 2 sr cm -1 ) 1.2x1-5 1.x1-5 8.x1-6 6.x1-6 4.x1-6 2.x1-6. IMG 9.5x1-6 9.x1-6 8.5x1-6 IASI 8 1 12 14 16 18 2 22 Wavenumber (cm -1 ) 2 87 875 88 885 89 895 IASI IASI spectral resolution (.5 cm -1 apodised) is coarser than IMG or TES (~.1cm -1 ) + IASI radiometric noise performances are above expectations
A long story 1993 1994 1995 1996 1997 1998 1999 2 21 22 23 24 25 26 IMG/ADEOS MOPITT/TERRA ACE/SCISAT TES/AURA IASI/MetOp Retrieval algorithm Data assimilation
2 complementary tools Near real-time (SA-NN) Columns CO, CH 4, O 3 Research (Atmosphit) profiles of any (IR absorbing) species errors averaging kernels Neural network based techniques Constrained retrieval: Optimal Estimation theory inputs y ˆ b Parameters adjustment outputs ˆx x 6 measurement radiance (W /cm 2 sr cm -1 ) 1.x1-5 O 3 8.x1-6 6.x1-6 4.x1-6 2.x1-6. 8 1 12 14 wavenumber (cm -1 ) altitude (km) 1 8 6 4 2 a priori information 1 2 3 4 5 6 7 8 O3 vmr (ppm) xˆ = Ax + (I A)xa + Gε [Hadji-Lazaro et al., 1999; Clerbaux et al., 21; Turquety et al., 22, 24] See poster [Coheur et al., 25; Barret et al., 25; Wespes et al., 27; Herbin et al., 27]
O 3 CH 4 CO Implemented in the Eumetsat ground segment [Turquety et al, JGR 24]
OZONE Complementary information provided by the NRT and offline processing total columns from SA-NN SA/CNRS ULB May 25, 27 Vertical profiles from Atmosphit 45 Validation Radiance (W / cm 2 sr cm -1 ) 8x1-6 6x1-6 4x1-6 2x1-7 observed residual best fit Tsurf = 288 K Tskin = 284 K Altitude (km) 4 35 3 25 2 15 1 5 a priori retrieved [O3] =399 DU -2x1-7 98 1 12 14 16 18 1x1 12 2x1 12 3x1 12 4x1 12 Wavenumber (cm -1 ) [O 3 ] (molecules cm -2 ) See poster
OZONE Radiance (W / cm 2 sr cm -1 ) 8.x1-6 7.x1-6 6.x1-6 5.x1-6 4.x1-6 3.x1-6 2.x1-6 1.x1-7. -1.x1-7 Altitude (km) 4 35 3 25 2 15 1 observed best fit IASI observed-calculated BT = 288 K ΔT = -4 K [O3]~4 DU 98 1 12 14 16 18 5 24-3 km Retrieval characterization; comparison between IASI and IMG 18-24 km 12-18 km..5 1. Wavenumber (cm -1 ) DOFS=5.1 6-12 km -6 km IMG observed BT = 288 K ΔT = -3 K [O3]~35 DU best fit observed-calculated 98 1 12 14 16 18 24-3 km 18-24 km 12-18 km 6-12 km -6 km..5 1. Averaging kernel DOFS=4.4 Altitude (km) 4 35 3 25 2 15 1 5 Layers Total error IASI Total error IMG 2 4 6 8 1 12 14 Total error 6 km 17 48 6 12 km 17 15 12 18 km 12 89 18 24 km 7 27 24 3 km 4 17 Retrieval error (%) A priori variability a priori variability (Mozart) similar performances IMG-IASI < 1 % error on the tropospheric column
TROPOSPHERIC OZONE See posters O3-SAF: GOME2+IASI
CARBON MONOXIDE Complementary information provided by the NRT and offline processing SA/CNRS ULB May 25, 27 3 1 2 East coast of USA latitude: +39.54 1 2 2 longitude: -72.42 Altitude (km) 15 1 5 a priori retrieved [CO] = 3.9 1 18 molecules cm -2 5 1 15 2 25 CO vmr (ppb) Altitude (km) 2 15 1 Northern Pacific 5 a priori latitude: +1.6 longitude: +153.66 retrieved [CO] = 1.99 1 18 molecules cm -2 5 1 15 2 25 CO vmr (ppb) 3 Altitude (km) Southern Pacific 2 15 1 5 latitude: -44.341 longitude: -1.47 retrieved [CO] = 1.27 1 18 molec. cm -2 a priori 5 1 15 2 25 CO vmr (ppb) Validation High thermal contrast case DOFS=1.8 21 km 19 km 17 km 15 km 13 km 11 km 9 km 7 km 5 km 3 km 1 km See poster DOFS: 1 to 2 -.1..1.2.3.4.5 Averaging kernel
2/8 24/8 25/8 CARBON MONOXIDE AVHRR 27825.955 UTC (http://www.eumetsat.int/home/main/media/news/316?l=en)
CARBON MONOXIDE Example of fires in Greece, August 27 8194_83 8194_82 7.x1-7 Radiance (W / cm 2 sr cm -1 ) 6.x1-7 5.x1-7 4.x1-7 3.x1-7 2.x1-7 1.x1-7 8194.83 8194.82. 1. Ratio.9 Fine scale composition variations within the plume are captured.8 CO enhancement.7 2 21 22 23 wavenumber (cm -1 )
CARBON MONOXIDE 8194_83 8194_82 Example of fires in Greece, August 27 4.x1-7 8194_83 8194_82 2 a priori (MOZART) Radiance (W / cm 2 sr cm -1 ) 3.x1-7 2.x1-7 Best fit Observed Best fit Observed 15 1.x1-8 Residual Residual. Altitude (km) 1 IASI spectrum 8194.83 [CO] = 7.9 1 18 molecules cm -2-1.x1-8 214 215 216 217 218 Wavenumber (cm -1 ) 214 215 216 217 218 Wavenumber (cm -1 ) 5 spectrum 8194.82 [CO] = 2.9 1 18 molecules cm -2 1 2 3 4 5 6 7 IASI conference-- CO mixing ratio November (ppb) 12-16, 27
SULFUR DIOXIDE SO 2 NRT detection criteria based on brightness temperature difference (ΔT) in ν 1 ΔT averaged for October 27 Bck@189.5 line@1132.62 line@117. 8x1-6 line@1129.25 line@1139.75 Bck@1231.5 Radiance (W / cm 2 sr cm -1 ) 7x1-6 6x1-6 5x1-6 4x1-6 IASI simulation no SO2 with SO2?? Jebel el-tair eruption on October 1 3x1-6 18 11 112 114 116 118 12 122 124 Wavenumber (cm -1 )
SULFUR DIOXIDE Jebel at-tair eruption, October 1, 27 OMI ~11: UTC IASI ~7:18 UTC AIRS
SULFUR DIOXIDE Jebel at-tair eruption, October 1, 27 Radiance (W / cm 2 sr cm -1 ) 1.2x1-5 1.x1-5 8.x1-6 6.x1-6 4.x1-6 2.x1-6. 71735.45 25 71759.45 8 1 12 14 16 18 2 22 24 26 s71735.45 s71759.45 1..5 Ratio 71759.45 / 71735.45 ν 1 SO 2 transmittance spectrum ν 3 11 115 12 125 13 135 14 Wavenumber (cm -1 )
SULFUR DIOXIDE Altitude (km) 3 2 1 Tropopause IASI [SO 2 ] = 28 ± 7 DU @ 7:18 UTC 1 2 3 4 5 6 7 8 SO2 vmr (ppb) Altitude (km) 3 25 2 15 1 ~SCIAMACHY 2 DU @ 12:3 UTC <OMI 35 DU @ 1:56 UTC Vertical sensitivity.5 km 1.5 km 2.5 km 4. km 6. km 8. km 1. km 12. km 14. km 16. km 18. km 2. km 22. km 24. km 5..1.2.3 Averaging kernel
SULFUR DIOXIDE Correlation with other species 3 SO 2 N 2 O CH 4 O 3 CO 2 2 Altitude (km) 1 Tropopause..5.2.4 1 2 3..2 4 6 vmr (ppm)
Conclusions and perspectives IASI spectra seem of very high quality level 1C received operationally since May 27 (> 1. 1 6 spectra daily) level 2 (P, T, clouds) received operationally since September 27 NRT processing O 3, CO columns and O 3 partial columns provided in NRT using the SA-Neural Network algorithm Preliminary comparisons with other space-based instruments show good agreement Some problems have been identified and need to be fixed (e.g. emissivity above desert) Current research processing O 3, CO profile with similar accuracy and vertical resolution than other sounders (to be confirmed on larger scale) CH 4 profiles using either ν 4 or ν 4 and ν 3 bands to increase sensitivity to the ground HNO 3 total columns Volcanic SO 2 Water isotopologues Others (CFCs, OCS)
Conclusions and perspectives Towards operational applications GMES 26 MetOp (IASI/GOME) 22 Ozone SAF EU FP7 CityZen IPY - Polarcat Volcanic threat