相关论文: Electrification of wind-blown sand on Mars and its…
Wind-blown sand, or "saltation," is an important geological process, and the primary source of atmospheric dust aerosols. Significant discrepancies exist between classical saltation theory and measurements. We show here that these…
Much of the surface of Mars is covered by dunes, ripples, and other features formed by the blowing of sand by wind, known as saltation. In addition, saltation loads the atmosphere with dust aerosols, which dominate the Martian climate. We…
It is a long-standing open question whether electrification of wind-blown sand due to tribocharging - the generation of electric charges on the surface of sand grains by particle-particle collisions - could affect rates of sand transport…
The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This article presents an extensive review of the physics of wind-blown sand and dust…
We apply a model for sand dunes to calculate formation of dunes on Mars under the present Martian atmospheric conditions. We find that different dune shapes as those imaged by Mars Global Surveyor could have been formed by the action of…
The wind-driven hopping motion of sand grains, known as saltation, forms dunes and ripples and ejects fine dust particles into the atmosphere on both Earth and Mars. While the wind speed at which saltation is initiated, the fluid threshold,…
Planet-encircling dust storms fundamentally reshape Martian weather and the near-surface electrostatic environment. We investigate the generation and evolution of electric fields during global dust storms using bimodal dust size…
Dust and sand motion are a common sight on Mars. Understanding the interaction of atmosphere and Martian soil is fundamental to describe the planet's weather, climate and surface morphology. We set up a wind tunnel to study the lift of a…
Emission of dust up to a few micrometer in size by impacts of sand grains during saltation is thought to be one source of dust within the Martian atmosphere. To study this dust fraction, we carried out laboratory impact experiments. Small…
We present the first calculation of saltation transport and dune formation on Mars and compare it to real dunes. We find that the rate at which grains are entrained into saltation on Mars is one order of magnitude higher than on Earth. With…
The absence of global magnetic fields is often cited to explain why Mars lacks a dense atmosphere. This line of thought is based on a prevailing theory that magnetic fields can shield the atmosphere from solar wind erosion. However, we…
Numerous laboratory experiments, starting in the Viking Lander era, have reported that frictional interactions between Martian analog dust grains can catalyze electrostatic processes (i.e. triboelectrification). Such findings have been…
Wind-blown sand, or "saltation", ejects dust aerosols into the atmosphere, creates sand dunes, and erodes geological features. We present a comprehensive numerical model of steady-state saltation that, in contrast to most previous studies,…
The illuminated dusty surface of Mars acts like a gas pump. It is driven by thermal creep at low pressure within the soil. In the top soil layer this gas flow has to be sustained by a pressure gradient. This is equivalent to a lifting force…
Surfaces of planetary bodies can have strong electric fields, subjecting conductive grains to repulsive electrostatic forces. This has been proposed as mechanism to eject grains from the ground. To quantify this process, we study mm-sized…
Atmospheric electrification is not a purely terrestrial phenomenon: all Solar System planetary atmospheres become slightly electrified by cosmic ray ionisation. There is evidence for lightning on Jupiter, Saturn, Uranus and Neptune, and it…
Within the RoadMap project we investigated the microphysical aspects of particle collisions during saltation on the Martian surface in laboratory experiments. Following the size distribution of ejected particles, their aerodynamic…
Production of runaway electron avalanches and gamma rays originating inside Martian dust storms are studied using Monte Carlo simulations. In the absence of in situ measurements, we use theoretical predictions of electric fields inside dust…
Airborne dust plays an active role in determining the thermal structure and chemical composition of the present-day atmosphere of Mars and possibly the planet's climate evolution over time through radiative--convective and cloud…
Atmospheric dust plays an important role on the terrestrial climate, regulating the amount of solar radiation coming to the surface, affecting the development and the life time of the clouds and providing fundamental nutrients to the growth…