SOIR Data Workshop SOIR science status A.C. Vandaele, A. Mahieux, S. Robert, R. Drummond, V. Wilquet, E. Neefs, B. Ristic, S. Berkenbosch, R. Clairquin

SOIR Data Workshop Scientific results  From SOIR measurements, construction of a database of vertical profiles of  CO 2 density  CO density  H 2 O density  HCl density  HF density  + isotopologues  CO 2 rotational temperature  CO rotational temperature  Aerosols  Measurements occur at terminator  All latitudes covered  Since 06/2006 till now

SOIR Data Workshop CO 2 density profiles Factor 10 Factor profiles

SOIR Data Workshop CO 2 rotational temperature profiles 60K

SOIR Data Workshop CO density profiles 80 profiles

SOIR Data Workshop CO rotational temperature profiles

SOIR Data Workshop Retrieval technique – Extinction profiles  Transmittances  Extinction :  With  aerosol slant opacity  T the transmittance  dz i the thickness of layer i  I i the atmospheric intensity of layer i  I 0 the full sun intensity  β i the extinction of layer i The SOIR instrument has the potential of characterizing the aerosols in the mesosphere of Venus. Previous work combining the 3 channels of SPICAV/SOIR showed aerosol layers in successive orbits corresponding to the presence of mode 2 particles of radius up to ~1.0 µm in the upper haze (not observed before). V. Wilquet, et al., J. Geophys. Research, Vol. 114, E00B42, 13 pp., 2009 Aerosols

SOIR Data Workshop Extinction profiles retrieved different wavelength  At high latitude North : extinction profiles are different for each wavelength  Around the equator: the extinction coefficient is less sensitive to the wavelength

SOIR Data Workshop Method:  Fit of the extinction in function of the wavelength  Refraction index model: spherical particles, 75% H 2 SO 4  Mie theory to derive extinction cross-section / Log-normal size distribution (r g,  g )  Normalization of the extinction (experimental and model)  Fitting experimental with theoretical values (minimization of merit function) Particle size and number density retrievals

SOIR Data Workshop Spatial coverage of measurements  Data spread over 3 years  Better coverage close to the North pole, due to the geometry of the orbit  Poor coverage between 40 and 60° N, due to orbit  Green crosses:spectra 3.0 µm

SOIR Data Workshop Latitudinal variation of the extinction  Period of 500 days (orbit till ) spread over all latitudes  µm:40 AM & 42 PM  Polynomial fit (2 d order) for each altitude

SOIR Data Workshop 80 km Season 11 Season 12 Season 13 Δ = evening terminator O = morning terminator

SOIR Data Workshop Three bands were rotationally analyzed: − G.S. (CO 2 628) ; ( CO 2 628) and G.S. ( CO 2 638) CO 2 spectroscopy 1.ASIMAT: retrieval of atmospheric parameters 2.New bands linelist, calibrated using HDO lines