Seasonal Variability of the Daytime and Nighttime Atmospheric Turbulence Experienced by InSight on Mars

TL;DR

This study uses InSight's pressure data over 1.25 Martian years to analyze seasonal and diurnal patterns of atmospheric turbulence, revealing significant vortex activity and turbulence variations linked to wind and seasonal changes.

Contribution

It provides the first detailed analysis of the seasonal and diurnal evolution of atmospheric turbulence on Mars using high-frequency pressure measurements from InSight.

Findings

Nighttime turbulence becomes as intense as daytime turbulence during northern autumn.

Vortices and local turbulence are strongly influenced by ambient wind conditions.

Seasonal changes affect the frequency and intensity of atmospheric turbulence events.

Abstract

The InSight mission, featuring continuous high-frequency high-sensitivity pressure measurements, is in ideal position to study the active atmospheric turbulence of Mars. Data acquired during 1.25 Martian year allows us to study the seasonal evolution of turbulence and its diurnal cycle. We investigate vortices (abrupt pressure drops), local turbulence (frequency range 0.01-2 Hz) and non-local turbulence often caused by convection cells and plumes (frequency range 0.002-0.01 Hz). Contrary to non-local turbulence, local turbulence is strongly sensitive at all local times and seasons to the ambient wind. We report many remarkable events with the arrival of northern autumn at the InSight landing site: a spectacular burst of daytime vortices, the appearance of nighttime vortices, and the development of nighttime local turbulence as intense as its daytime counterpart. Nighttime turbulence at this dusty season appears as a result of the combination of a stronger low-level jet, producing shear-driven turbulence, and a weaker stability.