DUST-2: Towards a more efficient (interactive) documentation and validation of scientific information demonstrated with ozone, water vapour and other selected data of the Earth's atmosphere

AbstractWith the rapid developments in the exoplanet field, more and more terrestrial exoplanets are being detected. Characterizing their atmospheres using transit observations will become a key datum in the quest for detecting an Earth-like exoplanet. The atmospheric transmission spectrum of our Earth will be an ideal template for comparison with future exo-Earth candidates. By observing a lunar eclipse, which offers a similar configuration to that of an exoplanet transit, we have obtained a high-resolution and high signal-to-noise ratio (SNR) transmission spectrum of the Earth's atmosphere. This observation was performed with the High Resolution Spectrograph at Xinglong Station, China during the total lunar eclipse in December 2011. We compare the observed transmission spectrum with our atmospheric model, and determine the characteristics of the various atmospheric species in detail. In the transmission spectrum, O2, O3, O2 · O2, NO2 and H2O are detected, and their column densities are measured and compared with the satellites data. The visible Chappuis band of ozone produces the most prominent absorption feature, which suggests that ozone is a promising molecule for the future exo-Earth characterization. Due to the high resolution and high SNR of our spectrum, several novel details of the Earth atmosphere's transmission spectrum are presented. The individual O2 lines are resolved and O2 isotopes are clearly detected. Our new observations do not confirm the absorption features of Ca II or Na I which have been reported in previous lunar eclipse observations. However, features in these and some other strong Fraunhofer line positions do occur in the observed spectrum. We propose that these are due to a Raman-scattered component in the forward-scattered sunlight appearing in the lunar umbral spectrum. Water vapour absorption is found to be rather weak in our spectrum because the atmosphere we probed is relatively dry, which prompts us to discuss the detectability of water vapour in Earth-like exoplanet atmospheres.

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The H2O–O2 water vapour complex in the Earth's atmosphere

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-10069-2011 ◽

2011 ◽

Vol 11 (3) ◽

pp. 10069-10086 ◽

Cited By ~ 2

Author(s):

Y. Kasai ◽

E. Dupuy ◽

R. Saito ◽

K. Hashimoto ◽

A. Sabu ◽

...

Keyword(s):

Equilibrium Constant ◽

Water Vapour ◽

Laboratory Experiments ◽

Lower Stratosphere ◽

Molecular Complexes ◽

Abundant Species ◽

Statistical Thermodynamic ◽

Earth’S Atmosphere ◽

Abundance Estimates ◽

Earth's Atmosphere

Abstract. Until recently, abundance estimates for bound molecular complexes have been affected by uncertainties of a factor 10–100. This is due to the difficulty of accurately obtaining the equilibrium constant, either from laboratory experiments or by statistical thermodynamic calculations. In this paper, we firstly present laboratory experiments that we performed in order to determine the molecular structure of H2O-O2. We also derive global abundance estimates for H2O-O2 in the Earth's atmosphere. The equilibrium constant Kp evaluated using the "anharmonic oscillator approach" (AHOA) (Sabu et al., 2005) was employed: the AHOA explains well the structure of the complex obtained by the present experiment. The Kp calculated by this method shows a realistic temperature dependence. We used this Kp to derive global abundance estimates for H2O-O2 in the Earth's atmosphere. The distribution of H2O-O2 follows that of water vapour in the troposphere and seems inversely proportional to temperature in the lower stratosphere. Preliminary estimates at the surface show amount of H2O-O2 is comparable to CO or N2O, ranking water vapour complexes among the ten most abundant species in the boundary layer.

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The H2O-O2 water vapour complex in the Earth's atmosphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-8607-2011 ◽

2011 ◽

Vol 11 (16) ◽

pp. 8607-8612 ◽

Cited By ~ 11

Author(s):

Y. Kasai ◽

E. Dupuy ◽

R. Saito ◽

K. Hashimoto ◽

A. Sabu ◽

...

Keyword(s):

Equilibrium Constant ◽

Water Vapour ◽

Laboratory Experiments ◽

Lower Stratosphere ◽

Molecular Complexes ◽

Abundant Species ◽

Statistical Thermodynamic ◽

Earth’S Atmosphere ◽

Abundance Estimates ◽

Earth's Atmosphere

Abstract. Until recently, abundance estimates for bound molecular complexes have been affected by uncertainties of a factor 10–100. This is due to the difficulty of accurately obtaining the equilibrium constant, either from laboratory experiments or by statistical thermodynamic calculations. In this paper, we firstly present laboratory experiments that we performed in order to determine the molecular structure of H2O-O2. We also derive global abundance estimates for H2O-O2 in the Earth's atmosphere. The equilibrium constant Kp evaluated using the "anharmonic oscillator approach" (AHOA) (Sabu et al., 2005) was employed: the AHOA explains well the structure of the complex obtained by the present experiment. The Kp calculated by this method shows a realistic temperature dependence. We used this Kp to derive global abundance estimates for H2O-O2 in the Earth's atmosphere. The distribution of H2-O2 follows that of water vapour in the troposphere and seems inversely proportional to temperature in the lower stratosphere. Preliminary estimates at the surface show amount of H2O-O2 is comparable to CO or N2O, ranking water vapour complexes among the ten most abundant species in the boundary layer.

Download Full-text