- 1Freie Universität Berlin, Institute of Geological Sciences, Department of Earth Sciences, Berlin, Germany (ankita.das@fu-berlin.de)
- 2Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstrasse 2, 12489 Berlin, Germany
- 3Remote Sensing Technology Institute, German Aerospace Center (DLR), Oberpfaffenhofen, -82234 Wessling
- 4Institute of Physics and Astronomy, University of Postdam, Karl-Liebknecht-Str, 24-25, 14476 Postdam, Germany
Radiative Transfer (RT) modeling is an essential tool to understand planetary atmospheres. In the coming decade, several missions to Venus are planned that aim to image Venus nightside thermal emission in the NIR spectral windows [1]. The NIR wavelength range of 0.8–1.2 µm contains spectral windows where Venus’ surface thermal emission radiation is detectable from space, paving the way for surface and near-surface atmosphere studies in these bands [2]. In order to process the data from these missions once they are available, RT modeling of the Venusian atmosphere is a necessary first step. The Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Venus (SPICAV) suite on board Venus Express made observations of Venus’ nightside in the spectral range of 0.65–1.7 µm [3] and provides a good baseline for a comparison with synthetic spectra. These spectra are based on molecular absorption cross-sections which in turn are governed by the line list chosen for the model. The HIgh-resolution TRANsmission molecular absorption database (HITRAN) is a frequently used line database in RT modeling [4]. Several Venus atmospheric studies (e.g., [5]), however, have relied on the database of [2] for CO2 lines, referred to as “Hot CO2” from here on. Newer line databases have been developed for high temperature atmospheres which are yet to be applied to Venusian atmospheric studies [4]. As part of this work we model nadir radiances for the Venusian atmosphere in the NIR range using a DISORT [7] algorithm and compare them to radiances produced with existing RT schemes used for modeling atmospheres (e.g., Planetary Spectrum Generator (PSG) [8]). In this work:
- We compare radiances produced considering absorption from relevant species present in the Venusian atmosphere using different line-lists: HITRAN 2020, HITEMP, Hot CO2 [2,4,6].
- We compare our modeled radiances to the observed SPICAV dataset
- We make further comments and predictions regarding parameters that need to be fine-tuned in order to reproduce the observed spectra from SPICAV.
References:
[1] Allen D. A. et al. (1984) Nature, 307, 222–224
[2] Pollack J. B. et al. (1993) Icarus, 103, 1–42
[3] Korablev O. et al. (2006) J. Geophys. Res. 111(E9)
[4] Gordon I. E. et al. (2022) J. Quant. Spectrosc. Radiat. Transfer, 277, 107949
[5] Bézard B. et al. (2011) Icarus, 216(1), 173–83
[6] Rothman L. S. et al. (2010) J. Quant. Spectrosc. & Radiat. Transfer, 111(12-13), 2139–2150
[7] Stamnes et al. (1988) Applied Optics, 27(12), 2502-2509
[8] Villanueva G. L. et al. (2018) J. Quant. Spectrosc. & Radiat. Transfer, 217, 86 – 104
How to cite: Das, A., Mueller, N., Schreier, F., Kappel, D., Grenfell, J. L., Rauer, H., Plesa, A.-C., and Helbert, J.: Radiative Transfer Modeling of Venus - A comparison of line databases, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18202, https://doi.org/10.5194/egusphere-egu25-18202, 2025.
