mars express atmospheric sciences inputs for tgo
Download
Skip this Video
Download Presentation
Mars Express «atmospheric sciences » Inputs for TGO…

Loading in 2 Seconds...

play fullscreen
1 / 65

Mars Express «atmospheric sciences » Inputs for TGO… - PowerPoint PPT Presentation


  • 163 Views
  • Uploaded on

Mars Express «atmospheric sciences » Inputs for TGO…. François FORGET Mars Express Interdisciplinary Scientist IPSL Laboratoire de Météorologie Dynamique CNRS, Paris, France + the Mars Express teams !. Outline. Introduction to Mars Express Mars meteorology Temperatures

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Mars Express «atmospheric sciences » Inputs for TGO…' - anoki


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
mars express atmospheric sciences inputs for tgo

Mars Express «atmospheric sciences »Inputs for TGO…

François FORGET

Mars Express Interdisciplinary Scientist

IPSL

Laboratoire de Météorologie Dynamique

CNRS, Paris, France

+ the Mars Express teams !

outline
Outline
  • Introduction to Mars Express
  • Mars meteorology
    • Temperatures
    • Surface pressure
    • Dust and clouds
  • Water vapor
  • Other Trace gases
slide3
Mars Express Orbiter
  • 7 main Instruments :
    • HRSC (camera) : visible
    • OMEGA (imaging Vis and NIR spectrometer) : 0.3-5.2 µm
    • PFS (NIR and thermal spectrometer): SWC:1.2-5.8 µm + LWC 6-50 µm
    • SPICAM (UV and NIR atmospheric spectrometer): 0.1-0.31 µm + 1-1.7 µm
    • ASPERA (Energetic Neutral Atoms Imager
    • MaRS: Radio Science Experiment
    • Marsis : Radar
pericenter latitude f t
Sun elevation

i < 0°

0 < i < 15°

15° < i <30°

I > 30°

Pericenter latitude = f(t)

10/01/04

30/05/04

  •  orbit 10000 upcoming this year
    • - Mission extension confirmed for 2011+2012
    • - and adopted for 2013+2014, pending mid-term confirmation.
thermal structure in the lower atmosphere with pfs
Thermal structure in the lower atmosphere with PFS

PFS

TES

spectral resolution 1.8 cm-1

slide8
Thermal structure below 50 km : LMD GCM prediction with Mars Express PFS (Giuranna et al. 2007)

Ls = 50°-70° (N. spring)

MorningEvening

60 km

40 km

20 km

PFS obs

GCM model

60 km

40 km

20 km

pfs aerosol thermal infared observations
PFS aerosol thermal infared observations

Silicate dust

Water ice clouds of different kinds

  • polar hood
  • topographic clouds
  • equatorial cloud belt
  • morning haze
  • night fog in Hellas
  • clouds above the melting polar cap.
slide10
One Lesson from Mars Express: Meteorology data from PFS (T(z), dust, clouds) could have been shared as well as possible and as early as possible with the other instruments team to help data processing

 Role of MCS on TGO

mars radio sciences p tzold et al tellmann et al
MaRS : radio sciences(Pätzold et al. Tellmann et al.)
  • uses the Radio Subsystem (High Gain Antenna) of
  • Mars Express
  • no Ultrastable Oscillator (only ingress)
  • But: higher sensitivity of measurement in Twoway
  • coherent downlink at two frequencies: X-Band (8.4 GHz)
  • S-Band (2.3 GHz)
mars radio sciences comparison with mgs
MaRS : radio sciencesComparison with MGS

(Pätzold et al. Tellmann et al.)

Solar Longitude

slide13
Comparison with MGS

Local Time

(Pätzold et al. Tellmann et al.)

slide14
Upper atmosphere temperature with SPICAM stellar occultations (60-130 km) [Forget et al. 2009]
slide16
Density to Temperature profiles

Spectra

Slant densities

CO2 density

Temperature

Ls = 11°, 16.8°N

principle of the pressure retrieval
Principle of the pressure retrieval
  • Retrieval: Least-square fitting w/ synthetic spectra from line-by-line radiative transfer
  • Inputs
  • Observation geometry e,i,φ
  • Atmospheric state T, τ
  • Surface properties
  • Surface pressure
  • Features
  • Dust absorption / simple scattering scheme
  • Multidimensional look-up tables

CO2 absorption at 2 microns

Forget et al. 2007

surface pressure oscillations
Surface pressure oscillations

Very flat topography

Spiga et al. 2007

temperature dust opacity pyroxenes instrumental noise
Temperature

Dust opacity

Pyroxenes

Instrumental noise

Relative error on a given pressure measurement

Forget et al. 2007

total relative error monte carlo random exploration
Total relative error: Monte-Carlo random exploration
  • 1-sigma relative error of
  • 7 Pa for A_L=0.29
  • 10 Pa for A_L=0.2
  • 15 Pa for A_L=0.15

OMEGA instrumental standard deviation was evaluated to 1.3 Pa

Forget et al. 2007

observation of aerosol at solar wavelengths
Observation of aerosol at solar wavelengths
  • OMEGA :
    • Nadir : not easy by several methods (Maatanen et al. 2010, Vincendon et al. 2007,2011 : dust brighter than expected; Doute et al. 2011 use effect on CO2 2µm band at high airmass)
    • Limb observations: very promising, but not yet fully analysed (Fouchet et al. 2006, Vincendon et al. 2011 more soon).
  • SPICAM: UV :
    • limb observations (Rannou et al. 2006)
    • Stellar occultation (Montmessin et al., 2006)
    • Solar occultation (Listowski, 2011)
  • SPICAM NIR : solar occultations
    • Fedorova et al. (2010)
slide26
Dust at the south pole

sun

surface reflectance is 0 at λ = 2.64 µm

reflectance factor

CO2 ice

wavelength (µm)

Vincendon et al. 2007,2009

slide27
Spatial variations of the dust optical depth

2004 / 2005

2006 / 2007

Vincendon et al. 2009

observation of aerosol at solar wavelengths1
Observation of aerosol at solar wavelengths
  • OMEGA :
    • Nadir : not easy by several methods (Maatanen et al. 2010, Vincendon et al. 2007,2011 : dust brighter than expected; Doute et al. 2011 use effect on CO2 2µm band at high airmass)
    • Limb observations: very promising, but not yet fully analysed (Fouchet et al. 2006, more soon).
  • SPICAM: UV :
    • limb observations (Rannou et al. 2006)
    • Stellar occultation (Montmessin et al., 2006)
    • Solar occultation (Listowski, 2011)
  • SPICAM NIR : solar occultations
    • Fedorova et al. (2010)
slide30
SPICAM IR – AOTF spectrometer:

Simultaneous observations of H2O, CO2 and aerosols

  • 1) H2O density from 1.38 mm band
  • 2) Atmospheric density from 1.43 mm CO2 band
  • 3) Aerosol extinction profiles and particle size distribution with 10 spectral points outside gaseous absorption bands

H2O

Aerosol points:

dashed lines

CO2

slide31
Problem with solar occultation – Pointing

Cause: mis-pointing of the real optical axis wrt predicted one

Solution: find the altitude shift that gives the best agreement

between observed and modeled CO2 profile

Method: weighted mean altitude difference of the profile

NOTE: recently studied by Scanning the solar disk in two orthogonal planes with constant θ/φ coordinates wrt. spacecraft body frame

<Δh> = 14.64 km

etc...

Maltagliatti et al.

sun occultation examples of spectra
Sun occultation examples of spectra
  • A principle of sequential scanning of a spectrum: short windows and dots
  • Two detectors
  • The record of a spectrum takes 4-6 seconds
  • Vertical resolution is 3.7 km with distance to limb 3000 km
  • A new optimal command for SPICAM IR permitting simultaneous observations of CO2, H2O and aerosol vertical distributions with spectral dependence of aerosol extinction in solar occultation mode was adapted only in April 2006

4 sec

4 sec

6 sec

4 sec

  • Fedorova et al. (2010)
vertical distribution of r eff
Vertical distribution of reff

Red line is the H2O refractive index, blue line is the ‘Marsdust’ model

Northern hemisphere

Reff ~0.4-0.8 mm

assuming a dust

Reff ~0.4-1.2 mm

assuming H2O

The size gradient has been

observed

High-altitude

cloud with

reff=0.1-0.3 mm

Southern hemisphere

  • Fedorova et al. (2010)
observation of water ice clouds at solar wavelengths
Observation of water ice clouds at solar wavelengths
  • SPICAM UV : Mateshvili et al. (2007)
  • OMEGA NIR : Madeleine et al. (2011): Mars water ice clouds opacity and particle size
  • LIMB observations
slide36
A difficult retrieval using two observations with and without clouds

(Madeleine et al. 2011)

slide39
Detection of high altitude CO2 ice clouds with OMEGA (Montmessin et al. 2007)
  • Opacity > 0.2
  • Altitude ~80 km
  • Reff up to 1.5 m

First spectroscopic identification by Mars Express (PFS, OMEGA, Formisano et al. 2006, Montmessin et al. 2007)

Observations by MOC & TES (Clancy et al. 2007), SPICAM (Montmessin et al. 2006), VMC, THEMIS (McConnochie et al.)

slide40
SPICAM stellar occultation

Forget et al. 2009

CO2

condensation

slide41
Detached aerosol layer simultaneously in the stellar occultation

Montmessin et al., Icarus 2006

CO2

condensation

slide42
Seasonal evolution map

OMEGA

HRSC

(spicam)

mars express h 2 o measurements
Mars Express H2O measurements
  • PFS spectral resolution 1.4 cm-1
    • LW 25-35 µm: processed by 2 groups: Fouchet et al., Icarus 2007
    • SW 2.56 µm: processed by 3 groups: Tschimmel et al., Icarus 2008.
  • OMEGA 2.56 µm mapping processed by 2 groups
    • Encrenaz et al. A&A 2005, 2008
    • Melchiorri et al. PSS 2007, Icarus 2009
    • Maltagliati et al., 2008; 2009 in press?
  • SPICAM 1.37 µm spectral resolution 3.5 cm-1 processed by one group
    • Fedorova et al., JGR 2006

Compared to Mars Global Surveyor TES

  • TES 25-50 µm, spectral resolution 6.25 or 12.5 cm-1

Korablev et al. 2009

on the difficulty of measuring water vapor comparison of mars express h 2 o measurements
On the difficulty of measuring water vapor : comparison of Mars Express H2O measurements

Korablev et al., ISSI group

usually

PFS LW ≤ SPICAM ≤ OMEGA ≤ TES ≤ PFS SW

PFS SW

OMEGA

SPICAM

PFS LW

side effects of mars express water vapour comparisons
Side effects of Mars Express water vapour comparisons

Korablev et al., ISSI group

  • TES/MGS database modification
    • Bug in processing low resolution (12.5 cm-1) portion of data
    • Reduction of H2O content in this data by 30%
  • MAWD/Viking dataset modification
    • Reprocessing of MAWD with new spectroscopic database (HITRAN 2004)
    • Reduction of the entire dataset by 60%
solar occultation water vapor retrieval maltagliatti et al in revision for science1
Solar occultation water vapor retrieval (Maltagliatti et al. : in revision for Science)

— Observation

— Model fit

solar occultation water vapor retrieval maltagliatti et al in revision for science2
Solar occultation water vapor retrieval (Maltagliatti et al. : in revision for Science)

— Observation

— LMD GCM

trace gas observations
Trace Gas Observations
  • Ozone
  • O2
  • NO
  • CO
  • SO2 ?
  • H2O2 ?
  • Methane
trace gas observations1
Trace Gas Observations
  • Ozone
    • Spicam NADIR
    • Spicam stellar occultation
slide52
SPICAM

observations in nadir mode

110-320 nm

Ozone Mapping with Spicam

CO2 O3

dust

clouds

surface

slide53
SPICAM raw spectra

SPICAM geometry

lon(t), lat(t), HL(t), Ls, SZA(t), x(t), f(t)

Mars Climate Database

surface pressure, T profile, O3 profile

Correction of darkcurrent

and stray light

Radiative Transfer Model

SHDOM

210-300 nm

0-60 km 12 layers

Averaging over 50 s

(250 spectra)

Division by

Data Reference Spectrum

Olympus Mons Ls =170° (Orbit 1448)

  • Levenberg-Marquardt fit
  • 4 free parameters:
  • ozone column
  • albedo at 210 nm
  • albedo at 300 nm
  • dust opacity
  • Optimal Parameters
  • ozone column
  • albedo at 210 nm
  • albedo at 300 nm
  • dust opacity

Spectral smoothing

(5 nm)

lat = 70°

lat = 60°

lat = 50°

262A01

Ls = 13.3

lat = 35°

slide54
spring

summer

autumn

winter

polar night

polar night

autumn

winter

spring

summer

SPICAM Ozone Column

Perrier et al., J. Geophys. Res., 2006

slide55
Analysis of SPICAM ozone columns with the LMD GCM

70N-90N

50N-70N

Lefèvre et al., Nature, 2008

GCM ozone column (micron-atmosphere)

slide56
summer

winter

summer

winter

summer

winter

O3 profile using SPICAM UV stellar occultation

(Lebonnois et al. 2007)

Comparison with GCM

Model Ozone column

trace gas observations2
Trace Gas Observations
  • O2
    • O2 florescence (1.27µm) resulting from dayside:
      • OMEGA nadir and Limb : Altieri et al. 2009;
      • SPICAM NIR Nadir and Limb Guslyakova et al. 2011;
      • PFS Geminale et al. 2011
    • O2 Recombination Nightglow Emission at 1.27 µm
      • OMEGA/MEX:Bertaux et al. 2011
      • SPICAM Guslyakova et al. 2011)
slide58
Altieri et al. 2009

Gravity waves on polar regions

as observed by OMEGA with O2 emission

Southern late winter/early spring MY28

Northern late winter MY26

Apparent MR

Altieri et al. 2009

Apparent MR

carbon monoxide
Carbon Monoxide
    • OMEGA (resolution Encrenaz et al. (2006)
      • CO main line :(2–0) at 2.35 µm
    • PFS
      • CO main line :(2–0) band centered at 4255 cm−1 (around 2.35 μm) difficult to use because of affected by mechanical vibrations
      • Billebaud et al. (2009) Billebaud et al. 4.7 μm spectra of Mars ((1–0) ro-vibrationnal)
  • Sindoni et al. PSS 2011: Measuring CO at 4235cm1 (2.36 µm) branch of (2–0) band
slide61
CO enrichment in Hellas: predicted by GCM, detected by OMEGA (Encrenaz et al. 2006)
  • CO main line :(2–0) at 2.35 µm

GCM : % of non condensible gaz

HELLAS

OMEGA observations:

HELLAS

trace gas observations3
Trace Gas Observations
  • Ozone
  • O2
  • CO
  • NO
  • SO2 : search in the UV with SPICAM UV nadir observations (Marcq et al. 2011)
  • H2O2 : search in the thermal IR using PFS with line at 362 cm-1 (+ 379, 416 and 433 cm-1). So far inconsistent results (Kasaba, Aoki et al. 2010)
  • Methane
methane pfs 3018 cm 1
Methane (PFS: 3018 cm-1)
  • Very difficult detection by Formisano et al. (Science 2004)
  • Further results by the PFS team published recently
    • A. Geminale, V. Formisano, M. Giuranna. Methane in Martian atmosphere: Average spatial, diurnal,and seasonal behaviour Planetary and Space Science 56 1194–1203(2008)
    • Geminale, Sindony, Formisano: Mapping methane in Martian atmosphere with PFS-MEX data Planetary and Space Science 59 137–148 (2011)

Enigmatic variability,

patchy behaviour

Geminale et al. 2008

ad