Soil Moisture Recognition and the Spatial Distribution of Storm Activity in the Mojave Desert Using High-Resolution ASTER and MODIS Imagery for Thermophysical Mapping

Climate models suggest that the Mojave Desert ecoregion is vulnerable to becoming drier in the future, and as the human population grows and development increases, environmental stresses will likely increase. Determining the spatial distribution and variation of soil moisture on a regional scale is an essential component to climate change, hydrologic, and habitat analyses. Soil permeability and sediment stability are characteristics that have been shown to be measurable from remote sensing observations. The primary objective of this project is to map the mechanical composition of the surface materials in the Mojave Desert ecoregion with implications for soil permeability, sediment stability, and soil moisture. We are using advanced mapping techniques to determine the surface mechanical compositions of the Mojave, with data provided by the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER), which provides the spatial resolution necessary to map the composition and thermal properties of arid surfaces and is well suited for mapping the spatial distribution of soil moisture. A full-resolution mosaic of thermal infrared (TIR) and visible to near infrared (VNIR) ASTER images has been constructed for the entire Mojave Desert for mapping surface components. With a 16-day repeat cycle, ASTER provides the high resolution mapping perspective, but lacks the temporal sampling to adequately quantify changes over days to weeks. Moderate Resolution Imaging Spectroradiometer (MODIS) data provides the temporal resolution needed to determine seasonal variations, although at a coarser spatial resolution. Our approach for mapping the Mojave Desert region involves using both ASTER and MODIS to provide the ideal spatial and temporal sampling to map individual storms and their effects on the seasonal conditions of the surface. The viability of the Mojave Desert ecosystem relies solely on infrequent storms and their temporal and spatial distribution over local regions and varied landscapes. Mapping the distribution of individual wetting events with regard to the geomorphology of the region can be a useful component for modeling potential changes as a function of climate change and human development providing a better understand of how random weather events contribute to the hydrologic cycle in the Mojave and potentially other arid regions around the world

Spatial Analysis of Common Raven Monitoring and Management Data for Desert Tortoise Critical Habitat Units in California

Common Ravens (Corvus corvax) are a native species in the Mojave Desert, but their populations have increased throughout the years due to resources provided by humans (ex. landfills, agriculture, standing water etc.). Increased densities of Ravens may have negative impacts on endangered or threatened species, such as the Desert Tortoise (Gopherus agassizii). We want to understand the Raven aggregations with respect to both anthropogenic and natural subsidies and their impacts on tortoise population. We have developed statistical models to provide spatial context to Raven nest density, nesting preferences, nesting success, and characteristics of offending nests throughout the Desert Tortoise Critical Habitat Units (CHU) in California. We analyzed nest survey data collected for nests on both anthropogenic and natural substrates using a variety of spatial methods to reduce autocorrelation bias, including spatial bootstrapping comparisons with null models, point process models, and geostatistical analyses. We found that nests on natural substrates tend to be located in areas that are have high Desert Tortoise suitability values, closer to agriculture, and in rougher terrain. Nests placed on anthropogenic substrates are more prominent in areas with high Desert Tortoise habitat suitability and closer to seasonal water resources. Fledgling success for both anthropogenic and natural nests were inversely correlated with temperature at the beginning of breeding season. We found negative effects on nest success relative to whether a nest was offending, indicating that these nests tended to be in areas with a suite of conditions that reduced success, and that the addition of tortoises into Raven diets did not in fact appear to improve the likelihood of success. This work will increase our understanding of the potential influence of anthropogenic features and subsidies in the desert, provide a spatial context on Raven threats to Desert Tortoise populations, and may have the potential to improve management tools and practices in managing Raven populations, which may ultimately aid in recovering Desert Tortoise populations

AEOLIAN SYSTEM DYNAMICS DERIVED FROM THERMAL INFRARED DATA

Thermal infrared (TIR) remote-sensing and field-based observations were used to study aeolian systems, specifically sand transport pathways, dust emission sources and Saharan atmospheric dust. A method was developed for generating seamless and radiometrically accurate mosaics of thermal infrared data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. Using a combination of high resolution thermal emission spectroscopy results of sand samples and mosaic satellite data, surface emissivity was derived to map surface composition, which led to improvement in the understanding of sand accumulation in the Gran Desierto of northern Sonora, Mexico. These methods were also used to map sand transport pathways in the Sahara Desert, where the interaction between sand saltation and dust emission sources was explored. The characteristics and dynamics of dust sources were studied at White Sands, NM and in the Sahara Desert. At White Sands, an application was developed for studying the response of dust sources to surface soil moisture based on the relationship between soil moisture, apparent thermal inertia and the erosion potential of dust sources. The dynamics of dust sources and the interaction with sand transport pathways were also studied, focusing on the Bodele Depression of Chad and large dust sources in Mali and Mauritania. A dust detection algorithm was developed using ASTER data, and the spectral emissivity of observed atmospheric dust was related to the dust source area in the Sahara. At the Atmospheric Observatory (IZO) in Tenerife, Spain where direct measurement of the Saharan Air Layer could be made, the cycle of dust events occurring in July 2009 were examined. From the observation tower at the IZO, measurements of emitted longwave atmospheric radiance in the TIR wavelength region were made using a Forward Looking Infrared Radiometer (FLIR) handheld camera. The use of the FLIR to study atmospheric dust from the Saharan is a new application. Supporting data from AERONET and other orbital data enabled study of net radiative forcing

The genes must flow: using movement ecology to understand connectivity of Mojave desert tortoise (Gopherus agassizii) populations in altered landscapes

Maintaining historic connectivity across animal populations is important to ensure a species can persist into the future. Human infrastructure and activities often fragment habitat, so understanding how connectivity functions is important in mitigation efforts. Connectivity arises from the movement of individuals within and between populations; understanding the movement ecology of a species can provide crucial information in how to best manage populations to maintain gene flow across a landscape. The Mojave desert tortoise (Gopherus agassizii) is a threatened species of the southwestern United States that historically had range-wide genetic connectivity. Human activity has and continues to alter and fragment tortoise habitat and maintaining/restoring connectivity across the range has been identified as an important conservation goal. In this work, I study the movement ecology of Mojave desert tortoises to understand how natural and anthropogenic features contribute to patterns of connectivity in the species. Corridors are important areas of a landscape that allow movement of animals between population centers through areas of unsuitable habitat. Due to assumed modest dispersal capabilities of the species, tortoises have been classified as corridor-dwellers that primarily rely on overlapping home ranges within an area for gene flow through a corridor. I studied tortoise movement selection and home ranges to understand what delineates both natural corridors through mountain passes and artificial corridors of suitable habitat left on the landscape after construction of utility-scale solar installations. Tortoises avoided areas of high slope and low perennial vegetation cover, avoided moving near low-density roads, and traveled along linear barriers. Results suggested that corridors through mountain passes can function differently in allowing tortoise movement, supporting prior findings using genetic differences. Artificial corridors created with fencing may not function the same way as natural corridors as a result of alteration of movement behavior. Although tortoises will avoid certain features such as roads, they will still interact with them. To better understand how anthropogenic and natural features alter tortoise movement behavior, I studied fine-scale tortoise movements using Hidden Markov movement models. My findings suggested that tortoises may respond to the same anthropogenic features (e.g. paved roads) differently depending on the context. Tortoises also alter movement in disturbed areas such as those with off-highway vehicle recreation or wildfire scars, suggesting that these disturbances degrade tortoise habitat. Using simulations of tortoise movement, I show that the behavioral responses to these disturbances may alter how tortoises are distributed on the landscape. Describing the long-term space use of individuals is key to understanding how genetic information flows across the landscape. Using historic and contemporary telemetry datasets (4,861 years of data from 950 tortoises), I related long-term site fidelity and dispersal in desert tortoises to intrinsic (size and sex) and extrinsic (seasonal precipitation) covariates. Tortoises display high site fidelity, though this fidelity is altered by seasonal precipitation and sex. Dispersal is more likely to occur in smaller tortoises and in years with high winter but low summer precipitation or years with low winter but high summer precipitation. I forecast future connectivity across the Ivanpah valley area with an agent-based model to estimate how future precipitation may influence connectivity by altering dispersal propensity. I found no differences in connectivity across emission scenarios, though other anthropogenic stressors will likely play a role in the future of connectivity in this species. This work provides insight into how tortoise movement at different spatial and temporal scales interact with habitat features and disturbances to alter connectivity of tortoise populations

Geology and Physical Properties Investigations by the InSight Lander

Although not the prime focus of the InSight mission, the near-surface geology and physical properties investigations provide critical information for both placing the instruments (seismometer and heat flow probe with mole) on the surface and for understanding the nature of the shallow subsurface and its effect on recorded seismic waves. Two color cameras on the lander will obtain multiple stereo images of the surface and its interaction with the spacecraft. Images will be used to identify the geologic materials and features present, quantify their areal coverage, help determine the basic geologic evolution of the area, and provide ground truth for orbital remote sensing data. A radiometer will measure the hourly temperature of the surface in two spots, which will determine the thermal inertia of the surface materials present and their particle size and/or cohesion. Continuous measurements of wind speed and direction offer a unique opportunity to correlate dust devils and high winds with eolian changes imaged at the surface and to determine the threshold friction wind stress for grain motion on Mars. During the first two weeks after landing, these investigations will support the selection of instrument placement locations that are relatively smooth, flat, free of small rocks and load bearing. Soil mechanics parameters and elastic properties of near surface materials will be determined from mole penetration and thermal conductivity measurements from the surface to 3–5 m depth, the measurement of seismic waves during mole hammering, passive monitoring of seismic waves, and experiments with the arm and scoop of the lander (indentations, scraping and trenching). These investigations will determine and test the presence and mechanical properties of the expected 3–17 m thick fragmented regolith (and underlying fractured material) built up by impact and eolian processes on top of Hesperian lava flows and determine its seismic properties for the seismic investigation of Mars’ interior

Mars in the Visible to Near Infrared: Two Views of the Red Planet

abstract: Remote sensing in visible to near-infrared wavelengths is an important tool for identifying and understanding compositional differences on planetary surfaces. Electronic transitions produce broad absorption bands that are often due to the presence of iron cations in crystalline mineral structures or amorphous phases. Mars’ iron-rich and variably oxidized surface provides an ideal environment for detecting spectral variations that can be related to differences in surface dust cover or the composition of the underlying bedrock. Several imaging cameras sent to Mars include the capability to selectively filter incoming light to discriminate between surface materials. At the coarse spatial resolution provided by the wide-angle Mars Color Imager (MARCI) camera aboard the Mars Reconnaissance Orbiter (MRO), regional scale differences in reflectance at all wavelengths are dominated by the presence or absence of Fe3+-rich dust. The dust cover in many regions is highly variable, often with strong seasonal dependence although major storm events can redistribute dust in ways that significantly alter the albedo of large-scale regions outside of the normal annual cycle. Surface dust reservoirs represent an important part of the martian climate system and may play a critical role in the growth of regional dust storms to planet-wide scales. Detailed investigation of seasonal and secular changes permitted by repeated MARCI imaging coverage have allowed the surface dust coverage of the planet at large to be described and have revealed multiannual replenishing of regions historically associated with the growth of storms. From the ground, rover-based multispectral imaging acquired by the Mastcam cameras allows compositional discrimination between bedrock units and float material encountered along the Curiosity rover’s traverse across crater floor and lower Mt. Sharp units. Mastcam spectra indicate differences in primary mineralogy, the presence of iron-bearing alteration phases, and variations in iron oxidation state, which occur at specific locations along the rover’s traverse. These changes represent differences in the primary depositional environment and the action of later alteration by fluids circulating through fractures in the bedrock. Loose float rocks sample materials brought into the crater by fluvial or other processes. Mastcam observations provide important constraints on the geologic history of the Gale Crater site.Dissertation/ThesisSupplemental Animations for Chapter 2Doctoral Dissertation Geological Sciences 201

Characterization of Impactite Clay Minerals with Implications for Mars Geologic Context and Mars Sample Return

Geological processes, including impact cratering, are fundamental throughout rocky bodies in the solar system. Studies of terrestrial impact structures, like the Ries impact structure, Germany, have informed on impact cratering processes – e.g., early hot, hydrous degassing, autometamorphism, and recrystallization/devitrification of impact glass – and products – e.g., impact melt rocks and breccias comprised of clay minerals. Yet, clay minerals of authigenic impact origin remain understudied and their formation processes poorly-understood. This thesis details the characterization of impact-generated clay minerals at Ries, showing that compositionally diverse, abundant Al/Fe/Mg smectite clays formed through these processes in thin melt-bearing breccia deposits of the ejecta, as well as at depth. The inherent complexity of smectites – their formation, type, structure, and composition – makes their provenance difficult to discern; these factors may explain why impact-generated and altered materials, which comprise an appreciable volume and extent of Mars’ ancient Noachian crust, are not generally recognized as a source of the enigmatic clays that are ubiquitous in those regions. Clay minerals can provide a defining window into a planet’s geologic and climatic past as an indicator of water availability and geochemistry; the presence of clay minerals on Mars has been used to support the hypothesis of climatically “warm, wet” ancient conditions. Yet, climate modeling of Early Mars suggests that the likely nature of the climate was not conducive to long-term aqueous activity. We suggest that the omission of impact-generated materials in current models of Mars clay mineral formation leaves a fundamental gap in our understanding of Noachian crustal materials – materials that were continually recycled and completely transformed on a global scale over millennia on Mars. The opportunity to investigate clay-bearing impactites and strata-bound clay minerals will be presented to the upcoming NASA Mars 2020 and ESA ExoMars rovers; this thesis offers caution in assigning clay mineral provenance until samples are returned to Earth from these missions. We furthermore suggest a methodological approach to augment current rover-based exploration frameworks to characterize potential impact-origin. Discerning clay species and provenance – and acknowledging the implications of that provenance – is central to understanding the geologic context of Mars, and thus its past climatic conditions and habitability potential

Annual Meeting of the Lunar Exploration Analysis Group : October 20 - 22, 2015, Columbia, Maryland, USRA Headquarters

The meeting goals are three-fold: 1. Integrate the perspectives and interests of the different stakeholders (science, engineering, government, and private sector) to explore common goals of lunar exploration. This meeting is focused around the identification, evaluation, extraction, and use of lunar resources. 2. Use the results of recent and ongoing missions to examine the dynamic nature of the Moon and how this could influence future science and exploration missions. 3. Provide a forum for community updates and input into the issues that affect lunar science and exploration.NASA Lunar Exploration Analysis Group (LEAG), Universities Space Research Association (USRA), Lunar and Planetary Institute (LPI), NASA Solar System Exploration Research Virtual Institute (SSERVI), National Aeronautics and Space Administration (NASA)Science Organizing Committee, James Carpenter, ESA-ESTE

Planetary Dunes Workshop, a record of climate change : April 29-May 2, 2008, Alamogordo, New Mexico

Sand dunes and other aeolian bedforms are a prominent part of landscapes shaped by wind action on several bodies in our solar system. Despite the three decades of study of these features, many questions regarding their composition and sediment sources, morphology, age, origins, and dynamics under present and past climatic conditions remain unanswered. Recently acquired data from orbiters and rovers together with innovative approaches using terrestrial analogs and numerical models are beginning to provide new insights into martian sand dunes, as well as aeolian bedforms on other terrestrial planetary bodies such as Titan.Lunar and Planetary Institute, NASA Mars Exploration ProgramScientific Organizing Committee Timothy Titus, U. S. Geological Survey, Rose Hayward, U. S. Geological Survey, Mary Bourke, Planetary Science Institute, Nick Lancaster, Desert Research Institute, Lori Fenton, Carl Sagan Center.PARTIAL CONTENTS: The Sand Seas of Titan: Discovery and Implications for Methane Climatology and Wind Patterns -- Comparative Point Pattern Analysis of Hyperboreae Undae, Mars, and the Rub'al Khali Sand Sea, Earth -- Hydrated Minerals in the North Polar Chasmata and Circum-Polar Erg -- Modeling 2-D Dune Interactions -- Global Survey of Martian Transverse Aeolian Ridges

Workshop on the Martian Surface and Atmosphere Through Time

The purpose of the workshop was to bring together the Mars Surface and Atmosphere Through Time (MSATT) Community and interested researchers to begin to explore the interdisciplinary nature of, and to determine the relationships between, various aspects of Mars science that involve the geological and chemical evolution of its surface, the structure and dynamics of its atmosphere, interactions between the surface and atmosphere, and the present and past states of its volatile endowment and climate system