Andrew D. Parsekian's research while affiliated with University of Wyoming and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (118)
Permafrost warming and degradation is well documented across the Arctic. However, observation‐ and model‐based studies typically consider thaw to occur at 0°C, neglecting the widespread occurrence of saline permafrost in coastal plain regions. In this study, we document rapid saline permafrost thaw below a shallow arctic lake. Over the 15‐year peri...
Integrated modeling of headwater watersheds in mountain environments is often limited by the lack of hydrological characterization and monitoring data. For the No-Name watershed in the Medicine Bow Mountains in Wyoming (USA), this research integrates regional surface and subsurface hydrological and geophysical measurements to create three-dimension...
Permafrost-affected ecosystems of the Arctic-boreal zone in northwestern North America are undergoing profound transformation as a result of rapid climate change. NASA’s Arctic Boreal Vulnerability Experiment (ABoVE) is investigating characteristics that make these ecosystems vulnerable or resilient to this change. ABoVE employs airborne synthetic...
Snowdrifts formed by wind transported snow deposition represent a vital component of the earth surface processes on Arctic tundra. Snow accumulation on steep slopes particularly at the margins of rivers, coasts, lakes, and drained lake basins (DLBs) comprise a significant water storage component for the ecosystem during spring and summer snowmelt....
Understanding the near-surface structure of the Earth requires accurate prediction of physical properties of the subsurface, such as velocity estimated from tomographic inversion of seismic refraction data. The predicted velocity values are often uncertain due to epistemic uncertainty in the inversion process (i.e., imperfectly known underlying phy...
Warming across the western United States continues to reduce snowpack, lengthen growing seasons, and increase atmospheric demand, leading to uncertainty about moisture availability in montane forests. As many upland forests have thin soils and extensive rooting into weathered bedrock, deep vadose‐zone water may be a critical late‐season water sourc...
Both hydrological and geophysical data can be used to calibrate hillslope hydrologic models. However, these data often reflect hydrological dynamics occurring at disparate spatial scales. Their use as sole objectives in model calibrations may thus result in different optimum hydraulic parameters and hydrologic model behavior. This is especially tru...
Seasonal subsidence induced by ground ice melt can be measured by interferometric synthetic aperture radar (InSAR) techniques to infer active layer thickness (ALT) in permafrost regions. The magnitude of subsidence depends on both how deep the soil thawed and how much ice/water content existed in the active layer soil. To provide the later, P‐band...
The hydrothermal system in Yellowstone National Park, arguably the most well-studied hydrothermal system in the world, offers a unique opportunity to study the complex interaction between deep, superheated, anoxic hydrothermal fluids and meteorically-sourced oxidizing waters in the near subsurface. Past research has established that hydrothermal wa...
Understanding the subsurface structure and function in the near-surface groundwater system, including fluid flow, geomechanical, and weathering processes, requires accurate predictions of the spatial distribution of petrophysical properties, such as rock and fluid (air and water) volumetric fractions. These properties can be predicted from geophysi...
Thermokarst lake dynamics, which play an essential role in carbon release due to permafrost thaw, are affected by various geomorphological processes. In this study, we derive a three-dimensional (3D) Stefan equation to characterize talik geometry under a hypothetical thermokarst lake in the continuous permafrost region. Using the Euler equation in...
Time‐lapse electrical resistivity tomography (ERT) data are increasingly used to inform the hydrologic dynamics of mountainous environments at the hillslope scale. Despite their popularity and recent advancements in hydrogeophysical inversion methods, few studies have shown how time‐lapse ERT data can be used to determine hydraulic parameters of su...
The formation, growth and drainage of lakes in Arctic and boreal lowland permafrost regions influence landscape and ecosystem processes. These lake and drained lake basin (L-DLB) systems occupy >20% of the circumpolar Northern Hemisphere permafrost region and ~50% of the area below 300 m above sea level. Climate change is causing drastic impacts to...
Snowdrift, which results from deposition of wind transported snow, has been primarily estimated empirically rather than using physically-based modeling since the snow redistribution process is extremely complex. This study demonstrates a practical predictive model for snow redistribution based on the Linear Particle Distribution (LPD) equation, whi...
Thermokarst lake dynamics, which plays an essential role in carbon release due to permafrost thaw, is affected by various geomorphological processes. In this study, we derive a three-dimensional (3D) Stefan equation to characterize talik geometry under a hypothetical thermokarst lake in the continuous permafrost region. Using the Euler equation in...
Abstract Interferometric synthetic aperture radar (InSAR) has been used to quantify a range of surface and near surface physical properties in permafrost landscapes. Most previous InSAR studies have utilized spaceborne InSAR platforms, but InSAR datasets over permafrost landscapes collected from airborne platforms have been steadily growing in rece...
In permafrost regions, active layer thickness (ALT) observations measure the effects of climate change and predict hydrologic and elemental cycling. Often, ALT is measured through direct ground-based measurements. Recently, synthetic aperture radar (SAR) measurements from airborne platforms have emerged as a method for observing seasonal thaw subsi...
Lake formation and drainage are pervasive phenomena in permafrost regions. Drained lake basins (DLBs) are often the most common landforms in lowland permafrost regions in the Arctic (50% to 75% of the landscape). However, detailed assessments of DLB distribution and abundance are limited. In this study, we present a novel and scalable remote sensin...
The occurrence and magnitude of natural fossil methane (CH4) emissions in the Arctic are poorly known. Emission of geologic CH4, a potent greenhouse gas, originating beneath permafrost is of particular interest due to the potential for positive feedback to climate warming, whereby accelerated permafrost thaw releases permafrost‐trapped CH4 in a fut...
Active layer thickness (ALT) is a critical metric for monitoring permafrost. How soil moisture influences ALT depends on two competing hypotheses: (a) increased soil moisture increases the latent heat of fusion for thaw, resulting in shallower active layers, and (b) increased soil moisture increases soil thermal conductivity, resulting in deeper ac...
Lakes and drained lake basins (DLBs) together cover up to ∼80% of the western Arctic Coastal Plain of Alaska. The formation and drainage of lakes in this continuous permafrost region drive spatial and temporal landscape dynamics. Postdrainage processes including vegetation succession and permafrost aggradation have implications for hydrology, carbo...
Agricultural water is of considerable interest to water managers and policymakers as irrigation—particularly flood irrigation—accounts for the largest portion of freshwater use. However, characterization of how and when flood applied water contributes to storage and adjacent surface water bodies via return flow remains limited, particularly relativ...
The belowground architecture of the Critical Zone consists of soil and rock in various stages of weathering and wetness that acts as a medium for biological growth, mediates chemical reactions, and controls partitioning of hydrological fluxes. Hydrogeophysical imaging provides unique insights into geometries and properties of the earth materials th...
A portion of water not consumed by crops during flood irrigation can flow back across the surface or through the subsurface to adjacent surface water bodies and streams as return flow. Few studies have directly addressed subsurface processes governing return flow and the importance of structural complexity on hydrologic process representation. It i...
Arctic lakes located in permafrost regions are susceptible to catastrophic drainage. In this study, we reconstructed historical lake drainage events on the western Arctic Coastal Plain of Alaska between 1955 and 2017 using USGS topographic maps, historical aerial photography (1955), and Landsat Imagery (ca. 1975, ca. 2000, and annually since 2000)....
The assessment of hydrologic ecosystem services associated with flood irrigation in the western United States is particularly limited by a lack of data about return flows. Return flows, the portion of applied water that returns to adjacent surface and groundwater hydrologic systems during flood irrigation, may provide wildlife habitat, recharge aqu...
Drought predisposes conifer forests to bark beetle attacks and mortality. Although plant hydraulic stress mechanistically links to tree mortality, its capacity to predict trees’ susceptibility to beetle attacks has not been evaluated. Further, both tree size and water supply could influence plant hydraulic stress, but their relative importance rema...
Core Ideas
Unsaturated saprolite, saturated saprolite, and fractured rock have unique NMR responses.
Surface NMR signals will be dominated by water in saturated saprolite.
The heterogeneous nature of fractured rock results in low‐amplitude surface NMR signals.
Understanding critical zone (CZ) structure below the first few meters of Earth's surface...
Flood irrigation is globally one of the most used irrigation methods. Typically, not all water that is applied during flood irrigation is consumed by plants or lost to evaporation. Return flow, the portion of applied water from flood irrigation that returns back to streams either via surface or subsurface flow, can constitute a large part of the wa...
Core Ideas
Time‐lapse imaging reveals subsurface flow paths driven by snowmelt.
Vertical flow occurs in the same location, but in a different amount, under varying water input.
Regolith geometry, observed by seismic refraction, drives partitioning to deep flow.
Understanding water partitioning and storage on mountain hillslopes is important for va...
![A schematic of fire response in permafrost [15]. (1) Fire removes...](publication/329765976/figure/fig3/AS:1132450797359108@1647008718253/A-schematic-of-fire-response-in-permafrost-15-1-Fire-removes-vegetation-and-part-of_Q320.jpg)
The Yukon–Kuskokwim (YK) Delta is a region of discontinuous permafrost in the subarctic of southwestern Alaska. Many wildfires have occurred in the YK Delta between 1971–2015, impacting vegetation cover, surface soil moisture, and the active layer. Herein, we demonstrate that the remotely sensed active layer thickness (ReSALT) algorithm can resolve...
Lakes in Arctic systems contribute to hydrologic storage, biogeochemical cycling, and permafrost thaw. Here, we have used surface nuclear magnetic resonance (NMR) measurements on lakes of Alaska’s North Slope to investigate the extent of permafrost thaw below lakes with different annual ice conditions. Our purpose is to understand if annual lake ic...
Strong winter warming has dominated recent patterns of climate change along the Arctic Coastal Plain (ACP) of northern Alaska. The full impact of arctic winters may be best manifest by freshwater ice growth and the extent to which abundant shallow ACP lakes freeze solid with bedfast ice by the end of winter. For example, winter conditions of 2016-1...
ERT IMAGING OF SUBSURFACE STRUCTURE OF A SINKHOLE IN GREENE COUNTY, MISSOURI
Shishay Kidanu, Missouri S&T; Evgeniy Torgashov, Missouri S&T; Neil Anderson, Missouri S&T
Thousands of sinkholes have been identified in the state of Missouri; Greene County, in particular, is one of the counties in the state most known for the occurrence of sinkholes....
Snow water equivalence (SWE) is typically computed from snow weight by the SNOTEL system in the US. However, a snow pillow, the main snow weight sensor used by SNOTEL, requires a large, open, flat area (at least 9 square meters) and substantial maintenance costs. This article presents the snow water equivalence estimation (SWEE) algorithm that esti...
Thermokarst lakes are prevalent in Arctic coastal lowland regions and sublake permafrost degradation and talik development contributes to greenhouse gas emissions by tapping the large permafrost carbon pool. Whereas lateral thermokarst lake expansion is readily apparent through remote sensing and shoreline measurements, sublake thawed sediment cond...
Ground penetrating radar (GPR) is a powerful hydrogeophysical tool for estimating porosity and water content of geologic materials using radar wave velocities and appropriate petrophysical relations. In substrates with more than one layer of interest, surface-based multi-offset measurements require careful analysis to accurately retrieve physical p...
In high‐mountain watersheds, the critical zone holds crucial life‐sustaining water stores in the form of shallow groundwater aquifers. To better understand role that the critical zone plays in moderating hydrologic response to fluxes at the surface and in the subsurface, the hydrologic properties must be characterized over large scales (i.e., that...
Small mountain lakes function as temporary storage basins for rain and snowmelt-derived water. Many small lakes lose water seasonally, but questions remain about the processes involved and effects on watershed hydrology. Evaporation and groundwater outflow from lakes may influence baseflow in streams, hydrologic connections among lakes, and water f...
In subalpine watersheds of the intermountain western United States, snowpack melt is the dominant water input to the hydrologic system. The primary focus of this work is to understand the partitioning of water from the snowpack during the snowmelt period and through the remainder of the growing season. We conducted a time-lapse electrical resistivi...
Ground penetrating radar (GPR) has emerged as an effective tool for estimating active layer thickness (ALT) and volumetric water content (VWC) within the active layer. In August 2013, we conducted a series of GPR and probing surveys using a 500 MHz antenna and metallic probe around Barrow, Alaska. We collected about 15 km of GPR data and 1.5 km of...
Mountain peatlands are susceptible to a changing climate via changes in the water cycle. Understanding the impacts of such changes requires knowledge of the hydrological processes within these peatlands and in the upland forests that supply them with water. We investigated hydrological processes in peatland catchments in the Rocky Mountains by deve...
Freshwater lakes are an important source of atmospheric methane (CH4); however, uncertainties associated with quantifying fluxes limit the accuracy of climate warming projections. Among emission pathways, ebullition (bubbling) is the principal and most challenging to account for given its spatial and temporal patchiness. When lakes freeze, many met...
In this investigation, we compare the results of electrical resistivity measurements made by six commercially available instruments on the same line of electrodes to determine if there are differences in the measured data or inverted results. These comparisons are important to determine whether measurements made between different instruments are co...
Dispersive Ground Penetrating Radar (GPR) signals can occur when a thin surficial layer overlies a basal layer of much greater or much smaller dielectric permittivity, such as a layer of ice overlying liquid water or a saturated zone overlying relatively dry soil. Dispersive signals can be analyzed using inversion of the phase velocity vs. frequenc...
Flood irrigation is one of the most common irrigation methods in the Intermountain West region of the United States. Return flow from flood irrigation to streams is an important component of the eco-hydrological cycle in agricultural areas. Return flow is often assumed to be approximately 50%, however, we need to improve our understanding of the ti...
Surface nuclear magnetic resonance (NMR) is a unique geophysical method due to its direct sensitivity to water. A key limitation to overcome is the difficulty of making surface NMR measurements in environments with anthropogenic electromagnetic noise, particularly constant frequency sources such as powerlines. Here we present a method of removing h...
Permafrost presence is determined by a complex interaction of climatic,
topographic, and ecological conditions operating over long time scales. In
particular, vegetation and organic layer characteristics may act to protect
permafrost in regions with a mean annual air temperature (MAAT) above
0 °C. In this study, we document the presence of residual...
Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0 °C. In this study, we document the presence of residual...
Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development b...
Infiltration rate is the key parameter that describes how water moves from the surface into a groundwater aquifer during managed aquifer recharge (MAR). Characterization of infiltration rate heterogeneity in space and time is valuable information for MAR system operation. In this study, we utilized fiber optic distributed temperature sensing (FO-DT...
Abstracts from SAGEEP 2016
Return flow is an important part of the water balance in semi-arid areas that rely on flood irrigation. We examine return flow processes from irrigated fields to streams, which can occur via different pathways: overland flow, near-surface return flow and via pathways below the vadose zone. The primary question to be addressed is how these different...
Active-layer thickness (ALT) is an important parameter for studying surface energy balance, ecosystems, and hydrologic processes in cold regions. We measured ALT along 10 routes with lengths ranging from 0.7 to 6.9 km located on the Alaska North Slope near Toolik Lake and the Happy Valley airstrip (between 68.475° and 69.150°N, and -149.512° and -1...
Spatial and temporal distribution of water flow paths in a high-mountain headwater (the ”NoName watershed”) in the Snowy Range are assessed using a parallel high performance integrated hydrologic model Parflow which simulates both surface and subsurface flow and their exchanges. The land surface of the model is defined by high resolution Lidar data...
Frozen regions of the earth are known as the cryosphere. The arctic, Antarctica, permafrost, ice sheets, and glaciers are some of the most challenging places to measure subsurface parameters, but they can also be some of the most important places to science and engineering research due to their susceptibility to environmental change. Ground-based,...
Surface Nuclear Magnetic Resonance (NMR) is a non-invasive geophysical technique providing the ability to image and investigate aquifer properties. In order to produce reliable images and interpretations of subsurface properties accurate modelling of the underlying physics is required. In magnetic environments, where the background magnetic field v...
This data set includes estimates of permafrost Active Layer Thickness (ALT; cm), and calculated uncertainties, derived using a ground-penetrating radar (GPR) system in the field in August 2014 near Toolik Lake and Happy Valley on the North Slope of Alaska. GPR measurements were taken along 10 transects of varying length (approx. 1 to 7 km). Traditi...