Designing a fully-tunable and versatile TKE-l turbulence parameterization for atmospheric models DOI Open Access
Étienne Vignon, Khadija Arjdal, F. Chéruy

et al.

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: April 26, 2024

This study presents the development of a TKE-l parameterization diffusion coefficients for representation turbulent in neutral and stable conditions large-scale atmospheric models. The has been carefully designed to be completely tunable sense that all adjustable parameters have clearly identified their number minimized as much possible help calibration thoroughly assess parametric sensitivity. We choose mixing length formulation depends on both static stability wind shear cover different regimes boundary layers. follow heuristic approach expressing functions Prandlt order guarantee versatility scheme its applicability planetary atmospheres composed an ideal perfect gas such Earth Mars. Particular attention also paid numerical at typical time steps used General Circulation Models. Test, sensitivity assessment preliminary tuning are performed single-column idealized simulations weakly layer. robustness assessed through implementation LMDZ Model Mars Planetary Climate by running Antarctic Martian nocturnal

Language: Английский

Turbulent Fluxes and Evaporation/Sublimation Rates on Earth, Mars, Titan, and Exoplanets DOI Creative Commons
Aditya Khuller, Gary D. Clow

Journal of Geophysical Research Planets, Journal Year: 2024, Volume and Issue: 129(4)

Published: April 1, 2024

Abstract Turbulent fluxes of heat, momentum, and humidity in the atmospheric boundary layer are pivotal to evolution geology, weather climate, possibility life. Here we extend recent advances calculating these near‐surface turbulent Earth's any terrestrial planetary body with an atmosphere. These improvements include: (a) incorporating Monin‐Obukhov similarity functions that encompass entire range stability expected on bodies, (b) accounting for additional shear associated buoyant plumes under unstable conditions, (c) using surface renewal theory calculate transfer rates within interfacial adjacent surface, (d) explicitly key effects become especially important when a volatile is more than ambient gas (e.g., Mars where H 2 O lighter CO ). We tested validated our model situ data collected Earth, Mars, Titan wide stability, pressure, roughness conditions. The shows up 71% better agreement measurements compared methods commonly used evaporation/sublimation. Compared previous estimates ice predicts 1.5–190x lower latent heat stable conditions (depending wind speed) 1.78x higher Our results provide improved constraints will help determine whether can melt present‐day

Language: Английский

Citations

4
Dry Downhill Particle Motion on Mars DOI Creative Commons
Tetyana Bila, Gerhard Wurm,

Kai Stuers

et al.

The Planetary Science Journal, Journal Year: 2024, Volume and Issue: 5(5), P. 115 - 115

Published: May 1, 2024

Abstract We recently flew a new setup on parabolic flights for the first time to study particle motion Martian slopes under gravity. Here, we describe initial experiments. used dust/sand beds at varying ambient pressure of few hundred pascals. The inclination bed was varied from 0° 45° and parts surface were illuminated conditions. could observe downhill material related insolation lowest light flux 591 ± 11 W m −2 JSC simulant. Motion occurred significantly lower inclinations illumination than without illumination, i.e., down about 10° compared 20°–30°, respectively. attribute this reduction in slope thermal creep gas flow subsoil. This induces Knudsen compressor, which supports grains against gravity leads smaller angles repose. is applicable recurring lineae Mars general.

Language: Английский

Citations

3
A Reappraisal of Subtropical Subsurface Water Ice Stability on Mars DOI Creative Commons
Lucas Lange, F. Forget, M. Vincendon

et al.

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(21)

Published: Nov. 9, 2023

Abstract Massive reservoirs of subsurface water ice in equilibrium with atmospheric vapor are found poleward 45° latitude on Mars. The absence CO 2 frost steep pole‐facing slopes and simulations atmospheric‐soil exchanges suggested that could be stable underneath these down to 25° latitude. We revisit arguments a new slope microclimate model. Our model shows below 30° latitude, warmer than previously estimated as the air above is heated by warm surrounding plains. This additional heat prevents formation surface for most slopes. suggests presence beneath possibly sparse dusty While unstable deposits might present, our results suggest rarer thought ±30° range considered human exploration.

Language: Английский

Citations

6
Observations of Water Frost on Mars With THEMIS: Application to the Presence of Brines and the Stability of (Sub)Surface Water Ice DOI Creative Commons
Lucas Lange, S. Piqueux, Christopher S. Edwards

et al.

Journal of Geophysical Research Planets, Journal Year: 2024, Volume and Issue: 129(10)

Published: Sept. 27, 2024

Abstract Characterizing the exchange of water between Martian atmosphere and (sub)surface is a major challenge for understanding mechanisms that regulate cycle. Here we present new data set ice detected on surface with Thermal Emission Imaging System (THEMIS). The detection based correlation bright blue‐white patterns in visible images temperature measured infrared too warm to be associated interpreted instead as ice. Using this method, detect down 21.4°S, 48.4°N, pole‐facing slopes at mid‐latitudes, any orientation poleward 45° latitude. Water observed THEMIS most likely seasonal rather than diurnal. Our consistent near‐infrared frost detections predictions by Mars Planetary Climate Model. average 170 K, maximum 243 lower melting point. Melting pure unlikely due cooling latent heat during its sublimation. However, show frosts are hot enough form brines if salts surface. vapor pressure surface, calculated from temperature, indicates dry early spring, recession cap. large amount released sublimation cannot stabilize subsurface mid‐latitudes.

Language: Английский

Citations

1
Designing a Fully‐Tunable and Versatile TKE‐l Turbulence Parameterization for the Simulation of Stable Boundary Layers DOI Creative Commons
Étienne Vignon, Khadija Arjdal, F. Chéruy

et al.

Journal of Advances in Modeling Earth Systems, Journal Year: 2024, Volume and Issue: 16(10)

Published: Oct. 1, 2024

Abstract This study presents the development of a so‐called Turbulent Kinetic Energy (TKE)‐l, or TKE‐l, parameterization diffusion coefficients for representation turbulent in neutral and stable conditions large‐scale atmospheric models. The has been carefully designed to be completely tunable sense that all adjustable parameters have clearly identified number minimized as much possible help calibration thoroughly assess parametric sensitivity. We choose mixing length formulation depends on both static stability wind shear cover different regimes boundary layers. follow heuristic approach expressing functions Prandlt order guarantee versatility scheme its applicability planetary atmospheres composed an ideal perfect gas such Earth Mars. Particular attention paid numerical convergence TKE equation at large time steps, essential prerequisite capturing layers General Circulation Models (GCMs). Tests, sensitivity assessments preliminary tuning are performed single‐column idealized simulations weakly layer. robustness assessed through implementation Laboratoire de Météorologie Dynamique Zoom GCM Mars Planetary Climate Model by running Antarctic Martian nocturnal

Language: Английский

Citations

0
Designing a fully-tunable and versatile TKE-l turbulence parameterization for atmospheric models DOI Open Access
Étienne Vignon, Khadija Arjdal, F. Chéruy

et al.

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: April 26, 2024

This study presents the development of a TKE-l parameterization diffusion coefficients for representation turbulent in neutral and stable conditions large-scale atmospheric models. The has been carefully designed to be completely tunable sense that all adjustable parameters have clearly identified their number minimized as much possible help calibration thoroughly assess parametric sensitivity. We choose mixing length formulation depends on both static stability wind shear cover different regimes boundary layers. follow heuristic approach expressing functions Prandlt order guarantee versatility scheme its applicability planetary atmospheres composed an ideal perfect gas such Earth Mars. Particular attention also paid numerical at typical time steps used General Circulation Models. Test, sensitivity assessment preliminary tuning are performed single-column idealized simulations weakly layer. robustness assessed through implementation LMDZ Model Mars Planetary Climate by running Antarctic Martian nocturnal

Language: Английский

Citations

0