The USGS Astrogeology Science Center conducts research on the interaction between planetary surfaces and the overlying atmospheres. In particular, the transfer of momentum (from wind), vapor (evaporation/sublimation), liquid (rainfall, percolation, infiltration) and solids (snow) occurs between surfaces and atmospheres.
Dunes and Ripples
Dunes and Ripples
One topic in particular that we focus on is the transport of sand and dust by wind. Flagstaff, AZ has numerous dunefields nearby, which we study via the Astrogeology Science Center Terrestrial Analogs Program. We are also interested in subaqueous dunes and ripples, as they may be analogs to bedforms under thicker atmospheres, such as those on Titan and Venus.
Terrestrial Analogs
Terrestrial Analogs
Imagery, soil temperature and humidity profiles, and meteorological data from December 2020 to April 2021, Grand Falls Dune Field, Arizona
Grand Falls dune field (GFDF) is located on the Navajo Nation, ~70 km NE of Flagstaff, AZ. This active dune field displays a range of morphologies, including barchans, smaller dunes, and ripples, and is bimodal in composition. The felsic component is likely derived from the Little Colorado River, and the mafic component (basaltic grains) is locally sourced from nearby cinder cones [1]. GFDF is an
Grand Falls, Arizona: Dune Field Sand Transport 2017 - 2019
As part of a NASA-funded study of sediment flux rates at a Mars analog site, we installed a suite of instruments in a small dune field near Grand Falls, Arizona. Data released in this report was collected from 02/07/2017 to 05/22/2019. The Grand Falls (GF) dune field is located on the Navajo Nation. It lies ~70 km NE of Flagstaff, AZ, 2 km east of Grand Falls, and just north of the Little Colorado
Grand Falls, Arizona: Dune Field Sand Transport 2013 - 2016
As part of a NASA-funded study of sediment flux rates at a Mars analog site, we installed a suite of instruments in a small dune field near Grand Falls, Arizona. Data released in this report were collected from 10/28/2013 to 11/04/2016. The Grand Falls (GF) dune field is located on the Navajo Nation. It lies ~70 km NE of Flagstaff, AZ, 2 km east of Grand Falls, and just north of the Little Colorad
Planetary Aeolian landforms: An introduction to the Fifth Planetary Dunes Workshop Special Issue
Aeolian landforms are widespread in our solar system. Understanding the exact nature and processes of formation of these features are challenging tasks necessitating a strong collaboration between scientists with different skills and scientific backgrounds. This paper describes the special issue for the 5th International Planetary Dunes Workshop, which includes 15 research papers and three comment
Aeolian processes and landforms across the Solar System: Science and technology requirements for the next decade
Discussions of planetary atmospheric-surface interactions (including aeolian processes and phenomena and the resulting landforms) are often tied to a specific planetary body. Considering this, a series of workshops were initiated in 2008 to facilitate an interdisciplinary and interplanetary body approach to further our understanding of aeolian processes, phenomena, and landforms (Titus et al., 200
A critical gap: In situ measurements of surface-atmosphere interactions from outside earth
This white paper demonstrates five points: (1) The lack of robust measurements of the vertical gradients of natural boundary layers and transport fluxes on other planetary bodies precludes adequate estimation of aeolian and other meteorological processes throughout our Solar System (§1). (2) Thus, there exist critical knowledge gaps within high-priority planetary science questions that motivate th
Ancient Martian aeolian sand dune deposits recorded in the stratigraphy of Valles Marineris and implications for past climates
Aeolian sediment transport, deposition, and erosion have been ongoing throughout Mars's history. This record of widespread aeolian processes is preserved in landforms and geologic units that retain important clues about past environmental conditions including wind patterns. In this study we describe landforms within Melas Chasma, Valles Marineris, that occur in distinct groups with linear to cresc
Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material) at the Mars Exploration Rover Opportu
Aeolian processes in Proctor Crater on Mars: Sedimentary history as analyzed from multiple data sets
Proctor Crater is a 150 km diameter crater in Noachis Terra, within the southern highlands of Mars. The analysis leading to the sedimentary history incorporates several data sets including imagery, elevation, composition, and thermal inertia, mostly from the Mars Global Surveyor mission. The resulting stratigraphy reveals that the sedimentary history of Proctor Crater has involved a complex intera
TES observations of the martian surface and atmosphere
The TES instrument is a Fourier transform Michelson interferometer operating with 10 or 5 cm-1 sampling int he thermal infared spectral region from 1700 to 200 cm-1 (~6 to 50 μm) where virtually all minerals have characteristic fundamental vibrational absorption bands (1, 2, 3, 4, 5, 6, 7, 8). The TES data used in this paper are among the 6x107 spectra collected during the early mapping phase of t
Aeolian features and processes at the Mars Pathfinder landing site
The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-
Triton's surface-atmosphere energy balance
We explore the energetics of Triton's surface-atmosphere system using a model that includes the turbulent transfer of sensible heat as well as insolation, reradiation, and latent heat transport. The model relies on a 1?? by 1?? resolution hemispheric bolometric albedo map of Triton for determining the atmospheric temperature, the N2 frost emissivity, and the temperatures of unfrosted portions of t
- Overview
The USGS Astrogeology Science Center conducts research on the interaction between planetary surfaces and the overlying atmospheres. In particular, the transfer of momentum (from wind), vapor (evaporation/sublimation), liquid (rainfall, percolation, infiltration) and solids (snow) occurs between surfaces and atmospheres.
Dunes and RipplesOne topic in particular that we focus on is the transport of sand and dust by wind. Flagstaff, AZ has numerous dunefields nearby, which we study via the Astrogeology Science Center Terrestrial Analogs Program. We are also interested in subaqueous dunes and ripples, as they may be analogs to bedforms under thicker atmospheres, such as those on Titan and Venus.
Terrestrial Analogs - Data
Imagery, soil temperature and humidity profiles, and meteorological data from December 2020 to April 2021, Grand Falls Dune Field, Arizona
Grand Falls dune field (GFDF) is located on the Navajo Nation, ~70 km NE of Flagstaff, AZ. This active dune field displays a range of morphologies, including barchans, smaller dunes, and ripples, and is bimodal in composition. The felsic component is likely derived from the Little Colorado River, and the mafic component (basaltic grains) is locally sourced from nearby cinder cones [1]. GFDF is anGrand Falls, Arizona: Dune Field Sand Transport 2017 - 2019
As part of a NASA-funded study of sediment flux rates at a Mars analog site, we installed a suite of instruments in a small dune field near Grand Falls, Arizona. Data released in this report was collected from 02/07/2017 to 05/22/2019. The Grand Falls (GF) dune field is located on the Navajo Nation. It lies ~70 km NE of Flagstaff, AZ, 2 km east of Grand Falls, and just north of the Little ColoradoGrand Falls, Arizona: Dune Field Sand Transport 2013 - 2016
As part of a NASA-funded study of sediment flux rates at a Mars analog site, we installed a suite of instruments in a small dune field near Grand Falls, Arizona. Data released in this report were collected from 10/28/2013 to 11/04/2016. The Grand Falls (GF) dune field is located on the Navajo Nation. It lies ~70 km NE of Flagstaff, AZ, 2 km east of Grand Falls, and just north of the Little Colorad - Publications
Planetary Aeolian landforms: An introduction to the Fifth Planetary Dunes Workshop Special Issue
Aeolian landforms are widespread in our solar system. Understanding the exact nature and processes of formation of these features are challenging tasks necessitating a strong collaboration between scientists with different skills and scientific backgrounds. This paper describes the special issue for the 5th International Planetary Dunes Workshop, which includes 15 research papers and three commentAeolian processes and landforms across the Solar System: Science and technology requirements for the next decade
Discussions of planetary atmospheric-surface interactions (including aeolian processes and phenomena and the resulting landforms) are often tied to a specific planetary body. Considering this, a series of workshops were initiated in 2008 to facilitate an interdisciplinary and interplanetary body approach to further our understanding of aeolian processes, phenomena, and landforms (Titus et al., 200A critical gap: In situ measurements of surface-atmosphere interactions from outside earth
This white paper demonstrates five points: (1) The lack of robust measurements of the vertical gradients of natural boundary layers and transport fluxes on other planetary bodies precludes adequate estimation of aeolian and other meteorological processes throughout our Solar System (§1). (2) Thus, there exist critical knowledge gaps within high-priority planetary science questions that motivate thAncient Martian aeolian sand dune deposits recorded in the stratigraphy of Valles Marineris and implications for past climates
Aeolian sediment transport, deposition, and erosion have been ongoing throughout Mars's history. This record of widespread aeolian processes is preserved in landforms and geologic units that retain important clues about past environmental conditions including wind patterns. In this study we describe landforms within Melas Chasma, Valles Marineris, that occur in distinct groups with linear to crescAeolian processes at the Mars Exploration Rover Meridiani Planum landing site
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material) at the Mars Exploration Rover OpportuAeolian processes in Proctor Crater on Mars: Sedimentary history as analyzed from multiple data sets
Proctor Crater is a 150 km diameter crater in Noachis Terra, within the southern highlands of Mars. The analysis leading to the sedimentary history incorporates several data sets including imagery, elevation, composition, and thermal inertia, mostly from the Mars Global Surveyor mission. The resulting stratigraphy reveals that the sedimentary history of Proctor Crater has involved a complex interaTES observations of the martian surface and atmosphere
The TES instrument is a Fourier transform Michelson interferometer operating with 10 or 5 cm-1 sampling int he thermal infared spectral region from 1700 to 200 cm-1 (~6 to 50 μm) where virtually all minerals have characteristic fundamental vibrational absorption bands (1, 2, 3, 4, 5, 6, 7, 8). The TES data used in this paper are among the 6x107 spectra collected during the early mapping phase of tAeolian features and processes at the Mars Pathfinder landing site
The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-Triton's surface-atmosphere energy balance
We explore the energetics of Triton's surface-atmosphere system using a model that includes the turbulent transfer of sensible heat as well as insolation, reradiation, and latent heat transport. The model relies on a 1?? by 1?? resolution hemispheric bolometric albedo map of Triton for determining the atmospheric temperature, the N2 frost emissivity, and the temperatures of unfrosted portions of t