# VenSpec Radiative Transfer Modeling Working Group

Justin Erwin, Shohei Aoki, Ankita Das, Itziar Garate Lopez, Cédric Gillman, Nils Mueller, Jaime Reyes Guerrero, Hideo Sagawa, Daphne Stam, Victor Trees, et al.

► To cite this version:

Justin Erwin, Shohei Aoki, Ankita Das, Itziar Garate Lopez, Cédric Gillman, et al. VenSpec Radiative Transfer Modeling Working Group. EPSC-DPS Joint Meeting 2025, Sep 2025, Helsinki, Finland. 10.5194/epsc-dps2025-1645. hal-05280842

HAL Id: hal-05280842

https://hal.science/hal-05280842v1

Submitted on 25 Sep 2025

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# VenSpec Radiative Transfer Modeling Working Group

Justin Erwin<fnref n="1" />, Shohei Aoki<fnref n="2" />, Ankita Das<fnref n="3" />, Itziar Garate Lopez<fnref n="4" />, Cédric Gillman<fnref n="5" />, Nils Mueller<fnref n="3" />, Jaime Reyes Guerrero<fnref n="4" />, Hideo Sagawa<fnref n="6" />, Daphne Stam<fnref n="12" />, Victor Trees<fnref n="7" />, Ann Carine Vandaele<fnref n="1" />, Sandrine Vinatier<fnref n="8" />, Yeon Joo Lee<fnref n="9" />, Giulia Alemanno<fnref n="10" />, Océana Barraud<fnref n="10" />, Emmanuel Marcq<fnref n="11" />, and Séverine Robert<fnref n="1" />

The VenSpec suite is a set of three spectrometers on board the EnVision M5 mission, which was adopted by ESA in 2024 to be launched in late 2031. EnVision is a medium class mission designed to assess, and possibly quantify, the nature and current state of geological activity on Venus, and its relationship with the atmosphere, to understand how Venus and Earth could have evolved so differently. The suite is composed of VenSpec-M (an infrared mapper), VenSpec-U (a UV spectral imager), and VenSpec-H (a high-resolution infrared spectrometer). The three spectrometers observe in NADIR and complement each other's day and night side observations.

The Radiative Transfer Modelling (RTM) working group is composed of scientists within the VenSpec suite science team interested in the topic of radiative transfer and its application to Venus' science. The group is a place to exchange knowledge and best practices for RTM in Venus atmosphere. The team will adapt the knowledge learned from previous space missions, past and ongoing ground-based measurement campaigns, and laboratory measurements to improve the RTM and, therefore, the future science return of the EnVision mission.

This presentation will outline the high-level topics, strategies of the working group, and overlap with the other working groups within the VenSpec Science Team. Some of the topics are

* RTM intercomparison (forward models, codes, retrieval methods, assumptions, inputs, outputs, etc.)

* Overlapping and/or complementary spectra bands. How can simultaneous observations be used to increase the science return?

* How can volcanism and active geography be observed with the VenSpec suite?

* Atmosphere models and reference scenarios (in collaboration with the VenSpec Atmospheric modelling Working Group)

* Surface and emissivity models and parameterization (in collaboration with the VenSpec Laboratory Investigation Working Group)

<footnote n="1">¹BIRA-IASB, Brussels, Belgium (justin.erwin@aeronomie.be)</footnote>

<footnote n="2">²Tokyo University, Tokyo, Japan</footnote>

<footnote n="3">³Freie Universität Berlin, Berlin, Germany</footnote>

<footnote n="4">⁴Universidad del País Vasco / Euskal Herriko Unibertsitatea (UPV/EHU), Leioa, Bizkaia, Spain</footnote>

<footnote n="5">⁵ETH Zurich, Switzerland</footnote>

<footnote n="6">⁶Kyoto Sangyo University, Kyoto, Japan</footnote>

<footnote n="7">⁷TU Delft, Delft, The Netherlands</footnote>

<footnote n="8">⁸LEISA/Observatoire de Paris, France</footnote>

<footnote n="9">⁹Institute for Basic Science, Daejeon, South Korea</footnote>

<footnote n="10">¹⁰DLR, Berlin, Germany</footnote>

<footnote n="11">¹¹LATMOS/Université de Versailles Saint-Quentin, Guyancourt, France</footnote>

<footnote n="12">¹²Leiden Observatory, Leiden, The Netherlands</footnote>
* Updates to molecular line lists, absorption cross sections, and aerosol/scattering phase functions (in collaboration with the VenSpec Laboratory Investigation Working Group)

* Previous satellite and ground-based data analyses (in collaboration with the VenSpec Ground Observation Working Group)

This presentation mainly serves to advertise the current membership (both the people and the institutes) and advertise for other interested parties.