Characterization of dust activity on Mars from MY27 to MY32 by PFS-MEX observations

TL;DR

This study analyzes dust activity on Mars over multiple years using PFS-MEX data, revealing seasonal patterns, inter-annual variations, and the impact of dust on atmospheric temperatures, with comparisons to TES-MGS measurements.

Contribution

It provides a comprehensive characterization of Martian dust activity from MY26 to MY33 using PFS-MEX data and compares it with TES-MGS observations, highlighting inter-annual differences and dust effects.

Findings

Large dust opacity in southern spring/summer

Good consistency between PFS-MEX and TES-MGS data during overlap

Global dust storm occurred in MY28 with distinct spatial and temporal features

Abstract

We present spatial and temporal distributions of dust on Mars from Ls = 331 in MY26 until Ls = 80 in MY33 retrieved from the measurements taken by the Planetary Fourier Spectrometer (PFS) aboard Mars Express. In agreement with previous observations, large dust opacity is observed mostly in the southern hemisphere spring/summer and particularly over regions of higher terrain and large topographic variation. We present a comparison with dust opacities obtained from Thermal Emission Spectrometer (TES) - Mars Global Surveyor (MGS) measurements. We found good consistency between observations of two instruments during overlapping interval (Ls = 331 in MY26 until Ls = 77 in MY27). We found a different behavior of the dust opacity with latitude in the various Martian years (inter-annual variations). A global dust storm occurred in MY28. We observe a different spatial distribution, a later occurrence and dissipation of the dust maximum activity in MY28 than in other Martian years. A possible precursor signal to the global dust storm in MY 28 is observed at Ls = 200 - 235 especially over west Hellas. Heavy dust loads alter atmospheric temperatures. Due to the absorption of solar radiation and emission of infrared radiation to space by dust vertically non-uniformly distributed, a strong heating of high atmospheric levels (40 - 50 km) and cooling below around 30 km are observed.