All Figures

$\begin{figure} \par\includegraphics[width=12cm,clip]{2247fig1.eps} \end{figure}$ Figure 1: The 555-559 GHz spectrum of water in Mars atmosphere in June 2003. Four 1 GHz wide AOS spectra separated by 700 MHz steps are combined. The 557.6 GHz tuning is missing due to partial failure in getting a properly tuned receiver. Corrections for beam dilution, pointing offset and beam efficiency have been applied. Average of 14-18 June observations. Four different mixing ratios (Q) with GCM temperature model (1) and $T_{\rm s}=260$ K surface temperature are superimposed on the spectrum. The $\pm$ 1 GHz wings of the lines put significant constraints on the water mixing ratio.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig2.eps} \end{figure}$ Figure 2: The central part (700 MHz) of the spectrum of water in Mars atmosphere shown at 1.2 MHz resolution. It actually corresponds to the 14.8 June 2003 observation. Same models as for Fig. 1 are superimposed. The frequency scale has been regularly calibrated on Earth atmospheric lines and should be accurate to better than 0.1 MHz.
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In the text

$\begin{figure} \par\includegraphics[width=12cm,clip]{2247fig3.eps} \end{figure}$ Figure 3: The 555-559 GHz spectrum of water in the Mars atmosphere (Nov. 2003). Five 1 GHz wide AOS spectra separated by 800 MHz steps are combined. Integration time was doubled in the central part, and shortened in the 557.7 GHz tuning (Table 1). Correction for beam dilution, pointing offset and beam efficiency have been applied. Models based on temperature profiles (1, GCM) and (2), from Fig. 9, with a fixed mixing ratio (Q), are superimposed on the spectrum.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig4.eps} \end{figure}$ Figure 4: Central part of the spectrum in Fig. 3, with same frequency scale as for H₂¹⁸O and CO lines in Figs. 6 and 7 for comparison.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig5.eps} \end{figure}$ Figure 5: Central 200 MHz of spectrum in Fig. 4. The 3 models correspond to different surface temperatures $T_{\rm s}=250$ , 260 and 270 K with same atmospheric profile and water abundance. The observed spectrum would need to be multiplied by factors 0.99, 1.03 and 1.07 respectively to fit the nearby continuum. The central peak absorption would then be slightly better modelled with the higher surface temperature, though requiring a larger correction for the continuum.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig6.eps} \end{figure}$ Figure 6: Spectrum of the H₂¹⁸O line in Mars obtained in November. The same models as in Figs. 3 and 4 have been superimposed and provide a good fit to the observed spectra. The spectrum has been scaled up by a factor 0.97 to agree with the continuum nearby level. The AC1 autocorrelator used for this observation was the least stable spectrometer and can well explain up to 10% difference in continuum level with other spectrometers. Uncertainties in pointing and receiver beams relative offsets (on the order of 10 $^{\prime \prime }$ ) and in beam efficiencies (Table 3) can also well explain differences of 5% between the continuum measured with each receiver (Figs. 3-7).
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig7.eps} \end{figure}$ Figure 7: Spectrum of CO line in Mars obtained in November. The same models as in Figs. 3-6 have been superimposed and provide a good fit to the observed spectrum. The spectrum has been scaled up by a factor 1.05 (See Fig. 6 for explanations). The width of the spectrum is 500 MHz as in Figs. 4 and 6, for comparison.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig8.eps} \end{figure}$ Figure 8: The 487.2 GHz integration spectrum in Mars centred on the O₂ line. All the observations have been used with an average pointing offset estimated to 15 $^{\prime \prime }$ . Pointing, beam dilution and efficiency corrections have been applied to retrieve the disc-averaged Rayleigh-Jeans temperature $T_{\rm RJ}$ and a curvature in the continuum coming from non-uniform $T_{\rm SYS}$ across the band has been removed. Models with the expected line and continuum intensity ( $T_{\rm s}=260$ K and 270 K, see text) have been superimposed.
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In the text

$\begin{figure} \par\includegraphics[angle=270,width=8cm,clip]{2247fig9.ps} \end{figure}$ Figure 9: Different thermal vertical profiles of the Mars atmosphere used in Figs. 1 to 7: temperature profile (1) is the GCM with a temperature inversion around 60 km. Profile (2) is the GCM with higher temperature at lower altitude, used in Figs. 3 to 7.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig2.eps} \end{figure}$	Figure 2: The central part (700 MHz) of the spectrum of water in Mars atmosphere shown at 1.2 MHz resolution. It actually corresponds to the 14.8 June 2003 observation. Same models as for Fig. 1 are superimposed. The frequency scale has been regularly calibrated on Earth atmospheric lines and should be accurate to better than 0.1 MHz.
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$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig4.eps} \end{figure}$	Figure 4: Central part of the spectrum in Fig. 3, with same frequency scale as for H₂¹⁸O and CO lines in Figs. 6 and 7 for comparison.
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$\begin{figure} \par\includegraphics[width=8.3cm,clip]{2247fig7.eps} \end{figure}$	Figure 7: Spectrum of CO line in Mars obtained in November. The same models as in Figs. 3-6 have been superimposed and provide a good fit to the observed spectrum. The spectrum has been scaled up by a factor 1.05 (See Fig. 6 for explanations). The width of the spectrum is 500 MHz as in Figs. 4 and 6, for comparison.
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$\begin{figure} \par\includegraphics[angle=270,width=8cm,clip]{2247fig9.ps} \end{figure}$	Figure 9: Different thermal vertical profiles of the Mars atmosphere used in Figs. 1 to 7: temperature profile (1) is the GCM with a temperature inversion around 60 km. Profile (2) is the GCM with higher temperature at lower altitude, used in Figs. 3 to 7.
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