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M. GHYSELS 1 , J. COUSIN 1 , N. AMAROUCHE 3 , L. GOMEZ-MARTIN 1 , E. D. RIVIERE 1 , G. DURRY 1,2

Development of PicoSDLA laser sensors for in-situ measurements of CH 4 , CO 2 and H 2 O in the UTLS in the frame of the TRO-pico project. M. GHYSELS 1 , J. COUSIN 1 , N. AMAROUCHE 3 , L. GOMEZ-MARTIN 1 , E. D. RIVIERE 1 , G. DURRY 1,2.

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M. GHYSELS 1 , J. COUSIN 1 , N. AMAROUCHE 3 , L. GOMEZ-MARTIN 1 , E. D. RIVIERE 1 , G. DURRY 1,2

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  1. Development of PicoSDLA laser sensors for in-situ measurements of CH4,CO2 and H2O in the UTLS in the frame of the TRO-pico project. M. GHYSELS1, J. COUSIN1, N. AMAROUCHE3, L. GOMEZ-MARTIN1, E. D. RIVIERE1, G. DURRY1,2 1 Groupe de Spectrométrie Moléculaire et Atmosphérique, GSMA, UMR CNRS 7331 UFR Sciences Exactes et Naturelles, BP 1039, 51687 REIMS Cedex 2 2 IPSL, Laboratoire Atmosphères, Milieux, Observations Spatiales, UMR CNRS 8190, 78280 Guyancourt, France 3 Division technique de l'Institut National des Sciences de l'Univers, 1, place Aristide Briand, 92195, Meudon Cedex, France.

  2. Scientific context • Sources of methane: • Anthropogenic : Fossils fuels production, rice cultivation, biomass burning, waste management, etc… • Natural : Wetland, non-wetland soil, gas hydrates, premafrost, termites, oceans, etc… + 150% More than 50% of methane emission come from human-related activities On per molecule basis, 25 times more efficient radiatively than CO2 molecule M. GHYSELS, GSMA

  3. Water vapor and methane in the stratosphere O3 depletion during winter 2011 In the tropics : Deep convection permits injection of species in the stratosphere by overshooting convection or slow ascent in the TTL Oxidation of CH4 in stratosphere: CH4 + OH CH3 + H2O Methane in stratosphere: source of water vapor Winter at poles: In the stratosphere, PSC formation → Ozone depletion M. GHYSELS, GSMA

  4. TRO-Pico balloon campaign (PI. E. D. Rivière, GSMA) Main Objective :Characterization of overshoots in order to quantify their impact on the hydratation of low stratosphere (regional → global scale) • Cirrus formation, impact of electricallycharged particules on TTL • Validation of satellites measurements of water vapour of IASI/Metop and SAPHIR/Megha-tropiques • Variability of lowstratospherehumidity : regularsounding of water vapour • Launchsfrom Bauru (Brazil, 22°S) • Collaboration: l’IPMet-UNESP M. GHYSELS, GSMA

  5. SDLA spectrometer, optical path lenght : 56m PicoSDLA-CH4 optical path lenght : 3.6 m Development of PicoSDLA-CH4 : scientific objectives PicoSDLA-CH4 ~15 kg : L= 3.6 m SDLA [Durry and G. Megie, (1999)] Total weight ~80 kg, L = 56m • PicoSDLA-CH4 : • Precision <5% • Measurement time reduced: • 10 ms to 1 s (measurementunder parachutes, speed ≈ 15 m.s-1) • Regularsoundingsundersmallmeteorologicalballoons M. GHYSELS, GSMA

  6. Based on direct absorption spectroscopy : F0 F Determination of mixing ratio from Beer-Lambert law : (low absorption hypothesis) Laser Détector S(Tatmos) : Line strenght [cm-1/molec cm-2] φ(Tatmos, Patmos, σ) : Line profile L : Optical path lenght [cm] NCH4 : Number of molecules M. GHYSELS, GSMA

  7. 1.5 µm Signal diode 3.24 µm PPLN crystal Optical fiber Pump diode CDFG Laser module 1 µm Output power ≈ 10µW Continuous coverage: 3076 to 3096 cm-1 Novawave Technologies (Dr. J. JOST), Inc. (USA) 20 cm x 12 cm x 2.5 cm, 980g Laser head DFG laser source → access to the R(6) transition of the ν3 band of CH4 (3086 cm-1, 3.24 µm) Strong fundamental band → Reduction of optical path lenght: 56m → 3.6 m In laboratory, determination of spectroscopic parameter (uncertainty <2%) M. GHYSELS, GSMA

  8. PicoSDLA-CH4 sensor Gold coating retroreflector Laser head Detector Germanium filter M. GHYSELS, GSMA

  9. 2 balloon campaigns: • ENRICHED, Kiruna 2011. Successfull test flight the 1st of April inside the polar vortex ComparisonTWIN/ PicoSDLA →good agreement Precision : 5% at 20km 1. 10-3 (PI A. Engels, University of Frankfurt) LOD 2. 10-4 M. Ghysels et al, Ap. Phys. B,104, Issue 4 (2011), Page 989-1000. PicoSDLA-CH4 onboard TWIN Kiruna M. GHYSELS, GSMA

  10. TRO-Pico Bauru (Brazil, 22°S) 1 scientific flight 14th of March 2012 Preliminary results : CH4, R(6) manifold, ν3band, Alt: 22.6 km PicoSDLA-CH4 flight 14th of March 2012 (Bauru) ρCH4 = 1.42 ± 0.05 ppmv PicoSDLA-CH4 before flight (Bauru, 2012) M. GHYSELS, GSMA

  11. Sensor PicoSDLA-H2O 1 m path lenght, 10kg weight TRO-Pico : 3 flights (march 2012) ENRICHED (2011): comparison with ELHYSA (PI. G. Berthet, LPC2E, Orléans) → good agreement 1m PicoSDLA-H2O , Bauru 2012 M. GHYSELS, GSMA

  12. Preliminary results 13th March 2012 Signature of overshoots ? M. GHYSELS, GSMA

  13. PicoSDLA-CO2 Calibration in laboratory: • Long time measurements (4h) from calibrated mixing of carbon dioxide and dry air • Allan variance : τAllan = 980 s, σAllan = 280 ppbv • Precision ≈ 1ppmv for 1s averaging time Calibrated value : 503.9 ppmv Calculated value : (502.6 ± 2.2) ppmv 4h M. GHYSELS, GSMA

  14. PicoSDLA-CO2 flights Objective : Lack of observations of the CO2 concentration’s decrease throught the UTLS [S. Park et al. (2010)] About ≈ 10 ppmv (mid-latitudes) • ENRICHED balloon campaign from Kiruna (67°N) : 1 flight the12th of March 2011 • Shortly : TRO-Pico balloon campaign from Bauru (22°S), 2 flights M. GHYSELS, GSMA

  15. Conclusion ENRICHED : Intercomparison TWIN/ PicoSDLA-CH4→ good agreement Intensities (uncertainty <2%), γselfdetermined Actually, temperature dependance of γair Validation of PicoSDLA-H2O by intercomparison ELHYSA/PicoSDLA Test flight of PicoSDLA-CO2 TRO-Pico : PicoSDLA-CH4: 1 flights and 1 future flight (Jan-Feb of 2013). PicoSDLA-H2O : 3 flights, 2 flights in convective conditions future: 15 background flights and 4 convective flights PicoSDLA-CO2: 2 flights (in convective conditions) M. GHYSELS, GSMA

  16. Thank you for attention M. GHYSELS, GSMA

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