Search Publications

Causes of Jets in the Quasi-Perpendicular Magnetosheath
DOI: 10.1029/2021GL093173 Bibcode: 2021GeoRL..4893173K

Kajdič, Primož; Raptis, Savvas; Blanco-Cano, Xóchitl +1 more

Magnetosheath jets are currently an important topic in the field of magnetosheath physics. It is thought that 97% of the jets are produced by the shock rippling at quasi-parallel shocks. Recently, large statistical studies of magnetosheath jets have been performed, however, it is not clear whether rippling also produces jets found downstream of qu…

2021 Geophysical Research Letters
Cluster 16
Delta Deposits on Mars: A Global Perspective
DOI: 10.1029/2021GL094271 Bibcode: 2021GeoRL..4894271D

Hauber, E.; Breuer, D.; De Toffoli, B. +1 more

Deltas have long been considered a constraining element to reconstruct the water level of an ancient ocean that may have once occupied the northern lowlands of Mars, and recently this hypothesis started to be challenged. We investigate this hypothesis and present a global inventory of fan-shaped features showing typical deltaic traits across the e…

2021 Geophysical Research Letters
MEx 14
Probing the Atmospheric Cl Isotopic Ratio on Mars: Implications for Planetary Evolution and Atmospheric Chemistry
DOI: 10.1029/2021GL092650 Bibcode: 2021GeoRL..4892650L

Vandaele, Ann Carine; Aoki, Shohei; Liuzzi, Giuliano +22 more

Following the recent detection of HCl in the atmosphere of Mars by ExoMars/Trace Gas Orbiter, we present here the first measurement of the 37Cl/35Cl isotopic ratio in the Martian atmosphere using a set of Nadir Occultation for MArs Discovery (NOMAD) observations. We determine an isotopic anomaly of −6 ± 78‰ compared to Earth …

2021 Geophysical Research Letters
ExoMars-16 12
New Results on the Direct Observations of Thermal Radio Emission from a Solar Coronal Mass Ejection
DOI: 10.1029/2020GL091048 Bibcode: 2021GeoRL..4891048R

Ramesh, R.; Kumari, A.; Kathiravan, C. +2 more

We report observations of thermal emission from the frontal structure of a coronal mass ejection (CME) using data obtained with the Gauribidanur RAdioheliograPH simultaneously at 80 and 53 MHz on May 1, 2016. The CME was due to activity on the far side of the Sun, but near its limb. No nonthermal radio burst activity was noticed. This provided an …

2021 Geophysical Research Letters
SOHO 11
A Long Term Study of Mars Mesospheric Clouds Seen at Twilight Based on Mars Express VMC Images
DOI: 10.1029/2020GL092188 Bibcode: 2021GeoRL..4892188H

Hueso, R.; Sánchez-Lavega, A.; Titov, D. +5 more

We present the first systematic study of clouds observed during twilight on Mars. We analyze images obtained by the Visual Monitoring Camera on Mars Express between 2007 and 2020. Using an automated retrieval algorithm, we found 407 cases of clouds observed at twilight, in which the geometry of the observations allows to derive the minimum altitud…

2021 Geophysical Research Letters
MEx 10
Precipitation Driven Pedogenic Weathering of Volcaniclastics on Early Mars
DOI: 10.1029/2020GL091551 Bibcode: 2021GeoRL..4891551Y

Michalski, J. R.; Ye, B.

Compositional stratigraphy, generally composed of Al rich clay minerals overlying Fe/Mg rich clay minerals, is observed in many locations on Mars. Here we describe the occurrence of such mineralogical stratigraphy in settings where the protoliths are almost certainly pyroclastic materials. One such example includes altered rocks high on the summit…

2021 Geophysical Research Letters
MEx 10
Enhanced Super-Rotation Before and During the 2018 Martian Global Dust Storm
DOI: 10.1029/2021GL094634 Bibcode: 2021GeoRL..4894634R

Fedorova, Anna A.; Holmes, James A.; Lewis, Stephen R. +3 more

Super-rotation affects—and is affected by—the distribution of dust in the martian atmosphere. We modeled this interaction during the 2018 global dust storm (GDS) of Mars Year 34 using data assimilation. Super-rotation increased by a factor of two at the peak of the GDS, as compared to the same period in the previous year which did not feature a GD…

2021 Geophysical Research Letters
ExoMars-16 10
Caldera Collapse as the Trigger of Chaos and Fractured Craters on the Moon and Mars
DOI: 10.1029/2021GL092436 Bibcode: 2021GeoRL..4892436L

Massironi, Matteo; Rossi, Angelo Pio; Pozzobon, Riccardo +3 more

Chaotic terrains are broad regions on Mars characterized by the disruption of the basaltic bedrock into polygonal blocks separated by deep fractures. To date, the proposed genetic scenarios often involve the occurrence of subsurface ice or liquid H2O. Nevertheless, similar features also occur within some craters on the Moon, namely floo…

2021 Geophysical Research Letters
MEx 10
Global Venus Solar Wind Coupling and Oxygen Ion Escape
DOI: 10.1029/2020GL091213 Bibcode: 2021GeoRL..4891213P

Fedorov, A.; Barabash, S.; Futaana, Y. +5 more

The present day Venusian atmosphere is dry, yet, in its earlier history a significant amount of water evidently existed. One important water loss process comes from the energy and momentum transfer from the solar wind to the atmospheric particles. Here, we used measurements from the Ion Mass Analyzer onboard Venus Express to derive a relation betw…

2021 Geophysical Research Letters
VenusExpress 9
Cassini Observation of Relativistic Electron Butterfly Distributions in Saturn's Inner Radiation Belts: Evidence for Acceleration by Local Processes
DOI: 10.1029/2021GL092690 Bibcode: 2021GeoRL..4892690Y

Krupp, N.; Wei, Y.; Roussos, E. +3 more

The morphology of electron pitch angle distributions (PADs) helps to identify dynamic processes in Saturn's magnetosphere. Previous studies demonstrated convective transport being important for relativistic electron acceleration at L > 4 in the inner magnetosphere, whereas closer to Saturn the situation is not as well established. We have inves…

2021 Geophysical Research Letters
Cassini 9