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Presentation to the “PFS data user workshop” June 27 – July 1, 2011 Madrid, Spain Example of Martian PFS spectra: spectral features and science results.

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Presentation on theme: "Presentation to the “PFS data user workshop” June 27 – July 1, 2011 Madrid, Spain Example of Martian PFS spectra: spectral features and science results."— Presentation transcript:

1 Presentation to the “PFS data user workshop” June 27 – July 1, 2011 Madrid, Spain Example of Martian PFS spectra: spectral features and science results

2 Single spectra measured by PFS south of the Volcano (gray), on top the caldera (top) and north of it in the plain (bottom). Only a short part of the SW channel spectrum is shown, to evidence the decrease of the CO 2 and CO on top of the mountain. Giuranna et al., 2005, ‘Calibration of the Planetary Fourier Spectrometer short Wavelenghth channel’, Planetary and Space Science 53, pp

3 The CO absorption lines in the 4.7 μm range. The synthetic spectrum is computed for 825 ppm of CO and is shown shifted by 0.45 CGS units for comparison. Simulation of the = 1-0 band of carbon monoxide.

4 Billebaud et al. (2009) - PSS 57, 1446–1457 G. Sindoni et al, 2011, PSS59, Observations of CO in the atmosphere of Mars with PFS

5 onboard Mars Express Set of spectra fitted with synthetic spectra. The corresponding retrieved CO mixing ratios are (from left to right and top to bottom): 7.5×10 -4, 9.3×10 -4, 8.7×10 -4, and 9.7× Billebaud et al., 2009, ‘Observations of CO in the atmosphere of Mars with PFS onboard Mars Express’, Planetary and Space Science 57, pp Data from Ls=331° (MY26) to Ls=51.61°(MY27) have been analyzed.

6 Observations of CO in the atmosphere of Mars with PFS onboard Mars Express CO mixing ratios retrieved as a function of surface pressure for three latitude ranges. Upper left: less than -30°. Upper right: between -30° and 30°. Bottom: higher than 30°. The other parameters are mixed. Surface pressure (coming from the MCD model) as a function of latitude for three L S ranges. From left to right and top to bottom: (a) 331–360°, (b) 0–30°, and (c) 30–52° The other parameters are mixed.

7 Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX Examples of continuum definition for PFS measured spectra in the absorption band spectral ranges for the CO. The black line is the measured spectrum and the red line is its continuum. The crosses are the spectral point used for the continuum definition. Spectral fit example of the carbon monoxide absorption band. Sindoni et al., 2011, ‘Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX ’, Planetary and Space Science 59, pp Data set from Ls=62° (MY27) to Ls=203° (MY29).

8 Map of retrieved concentration of carbon monoxide as a function of Longitude and Latitude as observed by PFS/SWC, from orbit 634 to orbit 6537, obtained using averaged spectra in square bins of 10° Longitude×10° Latitude for each season: Ls=0–90° (northern Spring), Ls=90−180° (northern Summer), Ls=180−270° (northern Fall) and Ls=305–360° (northern Winter). Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX Examples of mean latitudinal trends retrieved between Ls=90° and 120° (early northern summer) (left) and between Ls=240° and 270° (late northern fall) (right).

9 Water lines in the 2.7 μm range. The synthetic spectrum is computed for 300 ppm of H 2 O and is shown shifted by 0.5 CGS units for a better comparison.

10 Investigation of water vapor on Mars with PFS/SW of Mars Express Tschimmel et al., 2008, ‘Investigation of water vapor on Mars with PFS/SW of Mars Express’, Icarus 195, pp The normalized PFS spectrum (black line), that is created from the observational spectra 61–75 of orbit 278, is fitted by the synthetic spectrum (gray line). For the H 2 O fitting the region between 3820 and 3900 cm −1 was used yielding a mixing ratio of 225 ppm corresponding to a column density of 19.0 pr. μm at a saturation level of 19 km above the surface. The seasonal map of water vapor between L S = 330◦ of MY 26 and L S = 200◦ of MY 27. The martian H 2 O cycle is well covered in this period and shows a clear summer maximum (the highest value is 68 pr. μm).

11 Investigation of water vapor on Mars with PFS/SW of Mars Express For the three latitude bands of 60–90° N (upper panel), 30–60° N (middle panel) and 0–30° N (lower panel) the retrieved column densities were binned within 5° of Ls and multiplied with the respective area to get the total amount of water contained in the atmosphere of that latitude (given in g). The water vapor from the sublimation is transported by circulation further poleward and redeposited on the cold permanent ice cap. Later during the peak of the summer also this ice sublimes and produces the observed H2O peak with approximately 60 pr.  m (Montmessin et al., 2004).

12 Investigation of water vapor on Mars with PFS/SW of Mars Express Tharsis Arabia Terra The spatial distribution of water vapor for L S = 135–200◦ (northern autumn). The column densities, normalized to 6.1 mbar, are displayed up to 30 pr. μm.

13 Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX Examples of continuum definition for PFS measured spectra in the absorption band spectral ranges for the H 2 O. The black line is the measured spectrum and the red line is its continuum. The crosses are the spectral point used for the continuum definition. Spectral fit example of the water vapour absorption bands. Sindoni et al., 2011, ‘Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX ’, Planetary and Space Science 59, pp Data set from Ls=62° (MY27) to Ls=203° (MY29).

14 Map of retrieved abundance of water vapour as a function of Solar Longitude (Ls) and Latitude as observed by PFS/SWC, from orbit 634 to orbit 6537, obtained using spectra averaged in 5° Ls×5° Latitude bins. Observations of water vapour and carbon monoxide in the Martian atmosphere with the SWC of PFS/MEX

15 PFS measured and synthetic (shifted by 1.5 CGS units) spectrum in the cm −1 range showing a nonsaturated CO 2 band, a few solar and many water lines. Mars spectrum as measured by PFS (bottom) together with a pure solar spectrum (top).

16 A solar spectrum for PFS data analysis A portion of PFS Mars spectrum on Mars (average over 1680 measurements; orbits from 10 to 72) in which solar lines have been identified. Unknown is referred to features of uncertain origin. The broad band after 6860 cm -1 is due to atmospheric CO 2. The solar spectrum valid for PFS Fiorenza and Formisano, 2005, ‘A solar spectrum for PFS data analysis’, Planetary and Space Science 53, pp

17 Planetary Fourier Spectrometer observation of CO 2 (628) isotopologue on Mars Geminale and Formisano, 2009, ‘Planetary Fourier Spectrometer observation of CO2 (628) isotopologue on Mars ’, Journal of Geophysical Research, Volume 114, Issue E2 Average observed spectrum (black) and the synthetic spectrum (red) computed taking the albedo constant. The modified albedo.

18 Planetary Fourier Spectrometer observation of CO 2 (628) isotopologue on Mars Observed spectrum (black) and synthetic spectrum (red).The isotopic ratios for CO 2 (628) and CO 2 (627) are 0.80 and 0.96 of terrestrial standard value, respectively. Best fit to the observed PFS average spectrum (black) CO 2 (628)

19 Detection of Methane in the Atmosphere of Mars Spectra with 35 ppbv of methane. The error on the measurements is shown as ±1σ confidence lines. Geographical distribution of the orbits considered: red (high methane mixing ratio), yellow (medium methane mixing ratio), and blue (low methane mixing ratio). Strong fluctuations occur in each of the three categories, indicating the possible presence of localized sources. Formisano et al., 2004, ‘Detection of Methane in the Atmosphere of Mars’, Science, Volume 306, Issue 5702, pp

20 Mapping methane in Martian atmosphere with PFS-MEX data Average of 8249 spectra in the latitude range [30°, 50°] and all longitudes during northern fall For weak lines the equivalent width is linearly proportional to the column density: S q are the Hitran line intensities in the range [3017.3, ] cm -1. Geminale et al., 2011, ‘Mapping methane in Martian atmosphere with PFS-MEX data ’, Planetary and Space Science 59, pp

21 Spring: Ls=[0°:90°] Mapping methane in Martian atmosphere with PFS-MEX data Methane maps for each season. Summer: Ls=[90°:180°] Fall: Ls=[180°:270°]Winter: Ls=[270°:360°] Methane, being a non condensable gas, has an atmospheric abundance dominated by the polar CO2 condensation in local winter. Even if we do not cover the polar regions in local winter, we can observe the increase of methane northward or southward the equator.

22 Atreya et al., 2007, ‘Methane and related trace species on Mars: Origin, loss, implications for life, and habitability ’, Planetary and Space Science 55, pp Methane source…   Internal, such as volcanoes: for 10 ppbv of CH4 one should expect 1 – 10 ppmv of SO 2   Exogenous, such as meteorites, comets or interplanetary dust particles: the amount of methane delivered to Mars by the comets would be on the order of 1 ton yr -1   Internal, such as a hydrogeochemical process involving serpentinization: hydration of ultramafic silicates (Mg, Fe-rich) results first in the formation of serpentine and molecular hydrogen. The H 2 react with carbon grains or CO 2 of the crustal rocks/pores to produce methane   Biological: microbial colonies could exist in the subpermafrost aquifer environment on Mars, where microorganisms utilize CO and/or H 2, and produce methane in turn. If microorganism existed on Mars only in the past and produced methane, that methane could have been stored in methane-hydrates for later release. …and sinks   UV photolysis in the middle and upper atmosphere   Oxidation by O( 1 D) and OH   Oxidation by H 2 O 2

23 Albedo and photometric study of Mars with the Planetary Fourier Spectrometer on-board the Mars Express mission Esposito et al., 2007, ‘Albedo and photometric study of Mars with the Planetary Fourier Spectrometer on-board the Mars Express mission’, Icarus 186, pp With the present study, the authors intend to extract and analyze albedo properties at 7030 cm −1, where the thermal component of Mars radiance is negligible and there are no relevant features due to gas or aerosol. At this wavenumber radiance depends mainly on surface and atmospheric aerosol scattering properties. The same study has been repeated at 3900 cm −1 for comparison The Lambert’s law: R= (E S /π) *A L *cos i Which gives for Mars: A L =R M D 2 /[(E S /π) cos i] where E S and R M are solar irradiance at 1 AU and Mars radiance, respectively, both at 3900 cm −1 and D is the Sun– Mars distance.

24 Albedo and photometric study of Mars with the Planetary Fourier Spectrometer on-board the Mars Express mission Lambert albedo maps. The top panel has been extracted from the full resolved albedo map acquired by TES at a resolution of 8° per pixel by considering only the pixels corresponding to geographical points observed by PFS. The PFS Lambert map at 7030 cm −1 is in the bottom panel.

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26 Exercise on albedo Orbit 5639: save the spectrum with scet = sel_x_axes=x_axes(*,where(hk_struct.SCET_OBSERVATION_TIME eq )) sel_MarsRadiance=MarsRadiance(*,where(hk_struct.SCET_OBSERVATION_TIME eq )) save, sel_x_axes, sel_MarsRadiance,filename='orbita_5639_scet_ sav', /verbose Save geometry information: sel_INCIDENC_EANGLE=geo_struc(where(float(geo_struc.SCET) eq float( ))).INCIDENC_EANGLE sel_SOLAR_DISTANCE=geo_struc(where(float(geo_struc.SCET) eq float( ))).SOLAR_DISTANCE save, sel_INCIDENC_EANGLE, sel_SOLAR_DISTANCE,filename='info_geo_orbit_5639_scet_ sav', /verbose The same for orbit: 6493 scet = scet =

27 Nadir spectra in the 4.3  m region in Mars measured by PFS. Lopez-Valverde et al., 2005, ‘Analysis of CO2 non-LTE emissions at 4,3  m in the Martian atmosphere as observed by PFS/Mars Express and SWS/ISO’, Planetary and Space Science 53, pp Analysis of CO 2 non-LTE emissions at 4.3  m in the Martian atmosphere as observed by PFS/Mars Express and SWS/ISO

28 Analysis of CO 2 non-LTE emissions at 4,3  m in the Martian atmosphere as observed by PFS/Mars Express and SWS/ISO Nadir spectra in the 4.3  m region in Mars measured by ISO and PFS, together with a simulation computed with the nominal non- LTE model. Nominal results but locating the observer at various altitudes within the atmosphere, from 60 to 180 km, as indicated.

29 Geometry of the observations for orbit 1234, northern latitudes are given for the 71 measurements taken in this pass. Local time is 11:30. The subsolar point was at 16.3◦ N latitude. Geometry of limb observations

30 Observations of non-LTE emission at 4–5 microns with the planetary Fourier spectrometer abord the Mars Express mission Formisano et al., 2006, ‘Observations of non-LTE emission at 4–5 microns with the planetary Fourier spectrometer abord the Mars Express mission’, Icarus 182, pp Average spectrum over the entire set of measurements. Note the presence of the CO emission at 2100 cm −1. The red line is the deep space signal, while the blue curve is a Planckian at 190 K.

31 CO 2 non-LTE emission at 4.3  m M. Giuranna et al., in preparation SHa + SHb 626 main isotope FH FB 636 isotopic SHa + SHb New isotopic bands (1 st identification on Mars) CO 2 and CO Non-LTE emission has been observed with PFS LIMB observations Unprecedented coverage and spectral resolution Contributions from individual bands have been identified Emission from CO 2 isotopic molecules have been observed C12/C13 isotopic ratioC12/C13 isotopic ratio can be measured from observations of Non-LTE! Search for carbon isotopologues would help to test if life exists on MarsSearch for carbon isotopologues would help to test if life exists on Mars.

32 Exercise: ‘Visualize_spectrum.pro’ Select Spectrum from file ‘O2.sav’

33 Study of the oxygen day-glow in the Martian atmosphere with nadir data of PFS-MeX The maximum oxygen emission occurs at equinoxes over the polar regions. An emission at middle-low latitudes is observed at the aphelion with lower values respect to the polar regions. Geminale et al., in preparation. The photo-dissociation of ozone (O 3 ) by solar UV produces molecular oxygen in an excited state: O 3 + h  O 2 (a 1 Δ g ) + O The O 2 (a 1 Δ g ) may be de-excited by collisions (with CO 2 molecules) or emitting radiation at 1.27  m. Photo-dissociation of water….. H 2 O + h  H + OH H + O 2 + CO 2  HO 2 + CO 2 Ozone and water vapour are anti-correlated.

34 Study of the oxygen day-glow in the Martian atmosphere with nadir data of PFS-MeX Synthetic spectra The main emission peak is at 7882 cm -1 and at the PFS resolution many lines of the R branch (transitions with J’=J”+1) can be resolved. This allows us to retrieve the oxygen rotational temperature by means of the linear relation between the logarithm of the line intensity divided by the line strength factor and the energy of the upper rotational state.

35 PFS/MEX observations of the condensing CO2 south polar cap of Mars (a) (a)Mosaic of Mars Express OMEGA images showing the residual south polar cap (Ls=330°– 360°). It appears clearly asymmetric, the cap center being displaced by 3° far from the geographic pole. (b) (b)An example of PFS-data fit used to retrieve the RSPC composition. Black: PFS SWC spectrum of the RSPC (86° S, 20° W; Ls=338°). Red: Bi- Directional Reflectance model (DISORT; Stamnes et al., 1988). Intimate granular mixture of CO2 ice, water ice and dust. Stamnes et al., 1988 Giuranna et al., 2008, ‘PFS/MEX observations of the condensing CO2 south polar cap of Mars’, Icarus 197, pp Hansen et al., 2005, ‘PFS-MEX observation of ices in the residual south polar cap of Mars’, Planetary and Space Sciece 53, pp

36 PFS/MEX observations of the condensing CO2 south polar cap of Mars Spectrum with CO2 ice features vs a spectrum without ice features

37 Spatial variability, composition and thickness of the seasonal north polar cap of Mars in mid-spring Giuranna et al., 2007, ‘Spatial variability, composition and thickness of the seasonal north polar cap of Mars in mid-spring’, Planetary and Space Science 55, pp Best-fit of region I PFS averaged spectrum. The blue curve is the spectrum measured by PFS; the black curve is a BDR model of an intimate admixture of H 2 O ice (20-mm) and 0.15 wt % of dust. Best-fit of region II PFS averaged spectrum. The cyan curve is the spectrum measured by PFS; the BDR model (black curve) is a spatial mixture of 30% CO 2 ice (5mm grain size) and 70% of the same water ice as in region I. The CO 2 ice, in turn, is intimately mixed with 0.006wt% ofH 2 O ice. No dust is present in the mixture. Fresnel peak 3D surface plot of the Martian north polar cap at Ls 40° (MEX orbit 452). The RGB colors have been obtained from the spectra in the visible range acquired by OMEGA. The altimetry is retrieved from MOLA data.

38 Spatial variability, composition and thickness of the seasonal north polar cap of Mars in mid-spring Best-fit of region III PFS averaged spectrum. The red curve is the spectrum measured by PFS; the BDR model (black curve) is a mixture of CO 2 ice, with 0.003wt% of water ice 0.23wt% of dust. Best-fit of region IV PFS averaged spectrum. The orange curve is the spectrum measured by PFS which is best fitted by a mixture of CO 2 ice (grain size is 3 mm) and 0.02wt% of dust. Water ice is present as wt% in the intimate mixture, and as a 50% spatial fraction with the same composition as in region I. Best-fit of region V PFS averaged spectrum. The light blue curve is the spectrum measured by PFS; the black curve is a BDR model of an intimate admixture of 5mm sized CO 2 ice and 0.003wt% of water ice. No dust is required.

39 Exercise: ‘exercise_temperature.pro’ Select Spectrum from file ‘Mean_Spectrum_out_Olympus.sav’

40 Examples of measured spectra: spectrum above Olympus Mons and spectrum in Hellas region. Water clouds and dust aerosols observations with PFS MEX at Mars Zasova et al., 2005, ‘Water clouds and dust aerosols observations with PFS MEX at Mars’, Planetary and Space Science 53, pp Surface altitude corresponding to the centers of the FOV along orbit 37. Along x-axis is the spectrum number. Numbers along the curve indicate the mean particle size in the water ice clouds, which gives the best fit of the measured spectrum. The error of the mean particle size may exceed 0.5 μm  =  0 exp(-h/H 0 )

41 (a) PFS averaged spectrum. H 2 O 2 is identified at 362 cm -1 and 379 cm -1. There are two water vapor lines at 370 cm -1 and 375 cm -1. (b) The best-fit synthetic spectrum without H 2 O 2. (c) The best-fit synthetic spectrum with H 2 O 2 mixing ratio of 45 ppb. (d) the continuum slope (thick dotted line) and synthetic spectra (thick dashed curves) with the H 2 O 2 mixing ratio of 0, 30, 60, 90, 120 and 150 ppb. The continuum slope would be due to emissivity of the surface. Tentative detection of hydrogen peroxide (H2O2) in the Martian atmosphere with Planetary Fourier Spectrometer onboard Mars Express Aoki et al., 2011, ‘Tentative detection of hydrogen peroxide (H2O2) in the Martian atmosphere with Planetary Fourier Spectrometer onboard Mars Express’, in preparation. The seasonal variation of H 2 O 2 mixing ratio was ppb during the observational period from the Mars Year (MY) 27 to the MY 29.

42 Martian water vapor: Mars Express PFS/LW observations Example of fits of PFS spectra in the region of H 2 O rotational lines and CO 2 ν 2 band. Examples are chosen to illustrate two very different seasonal and surface temperature conditions. Seasonal distribution of water. Fouchet et al., 2007, ‘Martian water vapor: Mars Express PFS/LW observations’, Icarus 190, pp

43 Geographical distribution of water. Water columns are here normalized to a common 610 Pa pressure. Top left: entire dataset. Top right: Ls=330°–60°. Bottom left: Ls=90°–150°. Bottom right: Ls=155°–210°. Martian water vapor: Mars Express PFS/LW observations Comparison of water columns retrieved from PFS/LW and TES for measurements in common epoch. Left panel: original TES retrievals. Right panel:corrected TES retrievals, using the new version of the TES database.

44 CO2 isotopologues as seen with the PFS resolution in the LWC Isotopic Abundances Used for HITRAN

45 Conclusions PFS has been able to study: Minor species: CO, H 2 O, CH 4 (geographical and seasonal distribution) H 2 O 2 (seasonal distribution) CO 2 (628) O 2 (seasonal distribution) CO 2 non-LTE emission   Polar caps: composition and properties   Water clouds and aerosols More can be done:   Aerosols properties (size distributions, optical properties, chemical composition of dust and ice clouds)   Dust: composition, properties   Other minor species   Isotopologues: HDO, 13 C 16 O 2, 12 C 16 O 18 O for to estimate isotopic ratios   Clouds: optical properties of the atmospheric dust and ice clouds   Soil: thermal inertia, distribution of various materials, surface-atmosphere exchange processes.

46 Thank you!!!


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