The Venus Climate Database, current and future versions

Based on the state-of-the-art Venus Planetary Climate Model (PCM, formerly known as the Venus IPSL GCM) developed by our team[1-3], we have generated a Venus Climate Database (VCD) (http://www-venus.lmd.jussieu.fr/). This tool was developed with funding from ESA in the context of the preparation of the upcoming EnVision mission. The latest version of the VCD, VCD2.3, was released in fall 2023.

 

The VCD provides mean values and statistics of the main meteorological variables (atmospheric temperature, density, pressure and winds) as well as atmospheric composition and related physical fields. It extends from the surface up to and including the thermosphere (~250km). The database contains high resolution temporal outputs (using 24 hourly bins) enabling a good representation of the diurnal evolution of quantities over a climatological Venusian day.

As the goal of the VCD is to provide information about the state of the Venusian atmosphere, various realistic settings have been used to run a series of baseline GCM simulations, namely:

- Simulations using various Extreme UltraViolet (EUV) input from the Sun, as this forcing influences significantly the thermosphere (~120km and above).

- Some supplementary simulations with extreme values of UV cloud albedo, to bracket the state of the atmosphere below the thermosphere.

 

In addition to the aforementioned VCD scenarios, the following features are available:

- A "high resolution" mode based on a high resolution topography map (at 23 pixels/degree).

- Access to the Venusian intra-hour variability (RMS) of main meteorological variables, as well as the Venusian day-to-day variability thereof.

- The possibility to add perturbations to the climatological fields in order to generate realistic weather conditions.

 

VCD2.3 is distributed as (i) a main Fortran subroutine that users can interface and directly call from their own programs, interfaces to call this gateway routine using other programming languages (e.g. C, Python, IDL, Matlab, ...) are also provided; (ii) a web interface, for quick looks (http://www-venus.lmd.jussieu.fr).

 

We are currently working on the next version of the VCD, which should include not only updated Venus PCM simulation outputs (improved gravity waves scheme and better tuning of atmospheric oxygen) , but also some improvements in the VCD software (a redesigned gravity waves variability scheme, in line with the PCM updates) as well as on the inclusion of Global Climate Model simulation outputs from other teams.

 

References:

[1] Martinez, A .et al. Exploring the variability of the venusian thermosphere with the IPSL Venus GCM, Icarus (2023), DOI: 10.1016/j.icarus.2022.115272

[2] Stolzenbach, A. et al. Three-dimensional modeling of Venus photochemistry and clouds, Icarus, (2023), DOI: 10.1016/j.icarus.2023.115447

[3] Martinez, A. et al. Three-dimensional Venusian ionosphere model, Icarus (2024), DOI: 10.1016/j.icarus.2024.116035