Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

2019

Hydrology

Discipline
Institution
Publication
Publication Type

Articles 1 - 30 of 35

Full-Text Articles in Physical Sciences and Mathematics

Employing Earth Observations And Artificial Intelligence To Address Key Global Environmental Challenges In Service Of The Sdgs, Wenzhao Li Dec 2019

Employing Earth Observations And Artificial Intelligence To Address Key Global Environmental Challenges In Service Of The Sdgs, Wenzhao Li

Computational and Data Sciences (PhD) Dissertations

Earth Observation (EO) data provides the capability to integrate data from multiple sources and helps to produce more relevant, frequent, and accurate information about complex processes. EO, empowered by methodologies from Artificial Intelligence (AI), supports various aspects of the UN’s Sustainable Development Goals (SDGs). This dissertation presents author’s major studies using EO to fill in knowledge gaps and develop methodologies and cloud-based applications in selected SDGs, including SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), SDG 14 (Life below Water) and SDG 15 (Life on Land). For SDG 6, the study focuses on spatiotemporal water recharge …


Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard Dec 2019

Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historically wildfires have been beneficial to forests, however, human developments have encroached on forests when wildfire was artificially suppressed by federal and state agencies. The area burned by wildfire each year has increased twenty-fold in the past three decades. Large, high severity fires pose increased threats to human and aquatic communities within and downstream of the burned area due to post-wildfire effects on flooding and sedimentation. We need to understand the impacts of wildfires to be able to mitigate their damages and to recognize their potential benefits. This research addresses the questions: 1) Do wildfires impact rural and urban economies …


Estimation Of Evapotranspiration And Other Water Budget Factors At Glacier Creek Preserve, Kian Paul Mcintosh Dec 2019

Estimation Of Evapotranspiration And Other Water Budget Factors At Glacier Creek Preserve, Kian Paul Mcintosh

Theses/Capstones/Creative Projects

A water budget of a watershed consists of the inputs and outputs of water to and from it, including precipitation, change in water storage, surface water flow, and evapotranspiration. Water budget estimates are of high importance as a result of increasing demand due to population growth and other factors. Improving estimate accuracy and precision of evapotranspiration and runoff to streams allows scientists to better determine the true availability of water for human and conservation use. At Glacier Creek Preserve, 6.5% of the incoming precipitation left the preserve as discharge from the stream and 95.9% of the incoming precipitation was lost …


Vegetation, Rainfall, And Pulsing Hydrology In The Pantanal, The World's Largest Tropical Wetland, Sarah J. Ivory, Michael M. Mcglue, Stephanie Spera, Aguinaldo Silva, Ivan Bergier Nov 2019

Vegetation, Rainfall, And Pulsing Hydrology In The Pantanal, The World's Largest Tropical Wetland, Sarah J. Ivory, Michael M. Mcglue, Stephanie Spera, Aguinaldo Silva, Ivan Bergier

Earth and Environmental Sciences Faculty Publications

Wetlands provide valuable ecosystem services and play a central role in global carbon cycling. Changes in rainfall and the flood-pulse are likely to disrupt the processes that maintain these landscapes; further, landscape modification may dramatically alter wetlands and promote terrestrialization. The Pantanal, South America, is the world's largest wetland due to flooding along the Upper Paraguay River. Predicting how water resources in the Pantanal may change is problematic due to a complex drainage network, resulting in the out-of-phase timing of rainfall and the flood pulse. We use remote sensing data of vegetation and climate to better understand the relationships among …


Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm Oct 2019

Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm

Masters Theses

Vernal pools are small, ephemeral wetlands lacking an inlet or outlet. These wetlands, also known as seasonal pools, are found in a wide range of biomes, and their characteristics vary based on location. While the vegetation of western U.S. pools, and amphibians of eastern U.S. pools have been extensively studied, many aspects of vernal pools have not been fully characterized. In particular, although the general seasonal wetting and drying cycle is understood qualitatively, few studies have attempted to quantify the hydrological regime of vernal pools in New England. As water level variation drives many, if not all, of the characteristics …


Snow Depth Variability In The Northern Hemisphere Mountains Observed From Space, Hans-Peter Marshall Oct 2019

Snow Depth Variability In The Northern Hemisphere Mountains Observed From Space, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Accurate snow depth observations are critical to assess water resources. More than a billion people rely on water from snow, most of which originates in the Northern Hemisphere mountain ranges. Yet, remote sensing observations of mountain snow depth are still lacking at the large scale. Here, we show the ability of Sentinel-1 to map snow depth in the Northern Hemisphere mountains at 1 km² resolution using an empirical change detection approach. An evaluation with measurements from ~4000 sites and reanalysis data demonstrates that the Sentinel-1 retrievals capture the spatial variability between and within mountain ranges, as well as their inter-annual …


Effects Of Stormwater Green Infrastructure On Watershed Outflow: Does Spatial Distribution Matter?, Benjamin Fahy, Heejun Chang Oct 2019

Effects Of Stormwater Green Infrastructure On Watershed Outflow: Does Spatial Distribution Matter?, Benjamin Fahy, Heejun Chang

International Journal of Geospatial and Environmental Research

Green Stormwater Infrastructure (GSI) has become a popular method in urban stormwater management. We examined how spatial distribution of GSI affected rainfall-runoff relationships in a recently developed neighborhood in Gresham, Oregon, USA for the 2017-2018 water year. Runoff ratio, peak discharge, and flashiness were compared under four precipitation scenarios (of differing intensity and duration) and different spatial arrangements of GSI. Distributed GSI reduced runoff ratio (10 - 20%), peak discharge (26 - 68%), and flashiness index (56 - 70%). Distributed GSI outperformed centralized structures for all metrics, reducing runoff ratio (22 - 32%), peak discharge 67 to 69%, and flashiness …


The Relationship Between Forest Management And Stream Discharge In Mazumbai And Baga Ii Forest Reserves, Tanga Region, Tanzania, Shannon Duffy Oct 2019

The Relationship Between Forest Management And Stream Discharge In Mazumbai And Baga Ii Forest Reserves, Tanga Region, Tanzania, Shannon Duffy

Independent Study Project (ISP) Collection

Deforestation is known to alter hydrology by reducing interception, transpiration and infiltration capacity, and increasing runoff which all leads to higher stream discharge. For rural Tanzanian communities, surface water resources are crucial for meeting basic needs, so the integrity of headwater catchments need to be maintained to ensure their reliability. The objectives of this study were to a) map the streams in the two forests because none currently exist and b) determine the effect of deforestation on discharge variability. Over fifteen days of data collection, this study analyzed variability of discharge and the degree of correlation between discharge and rainfall …


Unconventional Energy, Fall/Winter 2015, Issue 31 Sep 2019

Unconventional Energy, Fall/Winter 2015, Issue 31

Sustain Magazine

No abstract provided.


An Exploration Into The Controls And Extent Of Capillary Rise In Fine-Grained Sand, Neal S. Turluck Aug 2019

An Exploration Into The Controls And Extent Of Capillary Rise In Fine-Grained Sand, Neal S. Turluck

Masters Theses

Capillary rise in fine-grained sands is especially important due to the wide distribution of fine-grained sediment throughout the unconsolidated sedimentary layers blanketing the earth. The height to which water rises above the water table in porous media is known as the capillary fringe. Tension pulling on the water molecules from the solid surfaces of pores will cause water to rise in the unconsolidated fine-grained sands until the water reaches equilibrium with the downward force of gravity.

Researching the controls behind capillary rise and being able to predict the extent to which water will rise in fine-grained sand helped provide insight …


Evaluating Sources Of Hydrochemical Variability And Mixing In The Upper Gila River, New Mexico, Pavel Vakhlamov Jul 2019

Evaluating Sources Of Hydrochemical Variability And Mixing In The Upper Gila River, New Mexico, Pavel Vakhlamov

Earth and Planetary Sciences ETDs

This study of the upper reaches of the Gila River basin in southwestern New Mexico reveals both spatial and seasonal patterns in physical and hydrochemical parameters. Monsoonal precipitation, temporal variability in water chemistry of streams in the upper Gila watershed is significantly impacted by surface runoff due to variability in landscape cover features, as well as surface area of the catchment. However, during base flow regimes spring inputs are the dominant drivers of solute concentrations and chemical variability.

Geothermal sources play a major role in salinization of the southwestern stream systems. Prolonged water/rock interaction combined with high temperature, pressure result …


Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend Jul 2019

Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend

Earth and Planetary Sciences ETDs

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on …


Decadal Changes Of Soil Physiochemical Properties In A Freshwater Wetland After Hydrologic Reconnection, Alina Spera Jun 2019

Decadal Changes Of Soil Physiochemical Properties In A Freshwater Wetland After Hydrologic Reconnection, Alina Spera

LSU Master's Theses

Sediment, nutrient deprivation and salt water intrusion, among other factors, are driving widespread organic soil collapse and marsh loss in the Mississippi River Delta. Freshwater diversions were designed to reintroduce Mississippi River water and dissolved nutrients into the adjacent basins to manage salinity and slow land loss by maintaining marsh vegetation and nutrient cycling functions. These diversions are controversial by a few, suggesting that nutrient enrichment without a sediment subsidy can lead to further wetland loss in the receiving basins. In this study, a soil characterization is presented for the receiving marsh of the Davis Pond diversion in 2007, just …


Characterizing The Waters Of 6 Rivers In Upstate New York With A Focus On Physical Hydrology And Controls On Water Quality, Connor Horan Jun 2019

Characterizing The Waters Of 6 Rivers In Upstate New York With A Focus On Physical Hydrology And Controls On Water Quality, Connor Horan

Honors Theses

Rivers are key passageways connecting inland waters to the world’s oceans. They are responsible for the mobilization and transport of nutrients, sediments, and weathered materials. Rivers have been influential in the development of human civilization and are hubs for people and businesses to populate. As our population puts a heavier burden on these waterways, there is a need to better understand the controls on their water quality.

The overarching goal of this research is to improve our understanding of the hydrology and water resources of the Upper Hudson and Mohawk watersheds. This is critical to our understanding of the ecological …


Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai Jun 2019

Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai

Civil & Environmental Engineering Faculty Publications

Probability-based intensity-duration-frequency IDF curves are needed but currently lacking for Department of Defense DoD to construct and manage its infrastructure in changing climate. The objectives of this project were to 1 develop an innovative approach for considering rainfall non-stationarity in developing such IDF curves and 2 apply this approach to the state of Virginia. In this regard, the observed data on 15-min rainfall at 57 gauges and the precipitations projected by twelve pairs of Regional Climate Model RCM and Global Circulation Model GCM were used. For a given gauge or watershed, in terms of fitting the empirical exceedance probabilities, a …


Feature Identification In Time Series Data Sets, Justin Shaw, Marek Stastna, Aaron Coutino, Ryan K. Walter, Eduard Reinhardt May 2019

Feature Identification In Time Series Data Sets, Justin Shaw, Marek Stastna, Aaron Coutino, Ryan K. Walter, Eduard Reinhardt

Physics

We present a computationally inexpensive, flexible feature identification method which uses a comparison of time series to identify a rank-ordered set of features in geophysically-sourced data sets. Many physical phenomena perturb multiple physical variables nearly simultaneously, and so features are identified as time periods in which there are local maxima of absolute deviation in all time series. Unlike other available methods, this method allows the analyst to tune the method using their knowledge of the physical context. The method is applied to a data set from a moored array of instruments deployed in the coastal environment of Monterey Bay, California, …


River Hydrology, Morphology, And Dynamics In An Intensively Managed, Transient Landscape, Sara Ann Kelly May 2019

River Hydrology, Morphology, And Dynamics In An Intensively Managed, Transient Landscape, Sara Ann Kelly

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers create beautiful patterns and provide drinking water to millions. However an alarming number of rivers in the US and globally are threatened by excess sediment and nutrients. Agricultural rivers draining erodible soils are particularly vulnerable. Rivers of southern Minnesota provide a unique opportunity to study water and sediment dynamics in a naturally vulnerable system. Sediment reduction strategies are needed to ensure biological integrity and adequate water quality. Here, I address the questions: 1) have climate, land use practices, or both affected streamflows in Midwest agricultural rivers?, 2) which streamflows set the rate of river bluff erosion?, and 3) how …


Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare May 2019

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a …


Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar May 2019

Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accurately extracting a meaningful transmissivity, a target value within one order of magnitude of field estimates, in numerical models poses a significant challenge when modeling complex groundwater systems. Aquifer transmissivity is directly proportional to the aquifer thickness and the estimated aquifer hydraulic conductivity. In complex geologic conditions (especially in fractured systems) with multiple heterogeneous and anisotropic hydrogeologic units, transmissivity can vary over several orders of magnitude.

To extract a meaningful value of transmissivity from a numerical model, a simple five-layer MODFLOW model was constructed. Each layer in the model was assigned a fixed hydraulic conductivity and thickness. The model simulates …


Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin T. Lynch, Douglas R. Easure, Daniel D. Magoulick Mar 2019

Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin T. Lynch, Douglas R. Easure, Daniel D. Magoulick

United States Geological Survey: Staff Publications

We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. …


Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin Thomas Lynch, Douglas R. Leasure, Daniel D. Magoulick Mar 2019

Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin Thomas Lynch, Douglas R. Leasure, Daniel D. Magoulick

United States Geological Survey: Staff Publications

We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. …


Ground, Proximal, And Satellite Remote Sensing Of Soil Moisture, Ebrahim Babaeian, Morteza Sadeghi, Scott B. Jones, Carsten Montzka, Harry Vereecken, Markus Tuller Mar 2019

Ground, Proximal, And Satellite Remote Sensing Of Soil Moisture, Ebrahim Babaeian, Morteza Sadeghi, Scott B. Jones, Carsten Montzka, Harry Vereecken, Markus Tuller

Plants, Soils, and Climate Faculty Publications

Soil moisture (SM) is a key hydrologic state variable that is of significant importance for numerous Earth and environmental science applications that directly impact the global environment and human society. Potential applications include, but are not limited to, forecasting of weather and climate variability; prediction and monitoring of drought conditions; management and allocation of water resources; agricultural plant production and alleviation of famine; prevention of natural disasters such as wild fires, landslides, floods, and dust storms; or monitoring of ecosystem response to climate change. Because of the importance and wide‐ranging applicability of highly variable spatial and temporal SM information that …


Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman Mar 2019

Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman

LSU Master's Theses

Rivers serve as an important medium for the exchange of elements between land, ocean, and atmosphere. This thesis consists of three interconnected studies with the overarching goal of analyzing the environmental factors influencing dissolved carbon dynamics and river geochemistry in large rivers. These studies utilized river water samples and in-stream measurements collected from the Mississippi and Atchafalaya Rivers at hourly to monthly intervals between 2013 to 2018, along with ambient river and meteorological data downloaded from public-access databases. Results indicate substantially higher dissolved organic carbon concentrations (DOC, 611 ±181 µmol L-1) but lower concentrations of dissolved inorganic carbon …


Long Reach Lane At Long Marsh, Harpswell, 2018 Post-Project Monitoring Report; Year 5 Of 5, Matthew Craig Mar 2019

Long Reach Lane At Long Marsh, Harpswell, 2018 Post-Project Monitoring Report; Year 5 Of 5, Matthew Craig

Publications

No abstract provided.


2014 - State Of The Salinas River Groundwater Basin Report, Executive Summary Jan 2019

2014 - State Of The Salinas River Groundwater Basin Report, Executive Summary

Miscellaneous Monterey and San Luis Obispo County Documents and Reports

An examination of the state of the Salinas River Groundwater Basin (Basin) was conducted in the last half of 2014 as part of the larger Basin Investigation. This Executive Summary of the State of the Basin Report addresses the ramifications of prolonged drought by considering likely changes in groundwater head elevations, groundwater storage, and seawater intrusion in the event that the current drought continues. In addition, some steps are presented that could be taken to help alleviate the consequences of further depleting groundwater storage.


Twenty-Three Unsolved Problems In Hydrology (Uph) – A Community Perspective, Günter Blöschl, Christopher M. U. Neale, A Cast Of Thousands Jan 2019

Twenty-Three Unsolved Problems In Hydrology (Uph) – A Community Perspective, Günter Blöschl, Christopher M. U. Neale, A Cast Of Thousands

Daugherty Water for Food Global Institute: Faculty Publications

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused …


Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher Jan 2019

Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher

Dissertations and Theses

Hindu Kush Himalayan (HKH) glaciers serve as some of the most sensitive indicators of changes in global climate. These glaciers shape the hydrologic dynamics of river systems supplying freshwater to over 2 billion people throughout Asia and regulate the geochemistry of sensitive aquatic alpine ecosystems. As snowmelt onsets sooner, lasts longer, and snowfields retreat due to increases in global temperature, the hydrologic dynamics of catchments draining HKH threaten to change the availability of surface freshwater resources for nearly one fifth of the global population, disturb sensitive aquatic habitat, and precipitate hazards associated with glacier wasting. Informed planning and decision-making around …


Introductory R For Water Resources - Fall 2019 - University Of North Carolina At Chapel Hill, David Gorelick, Gregory Characklis Jan 2019

Introductory R For Water Resources - Fall 2019 - University Of North Carolina At Chapel Hill, David Gorelick, Gregory Characklis

All ECSTATIC Materials

This is all course material for R for Researchers, a one-credit course taught at UNC Chapel Hill in Fall 2019 to introduce upperclassmen and graduate students to the R programming language and apply learned skills in basic water resources applications, as well as other (semi-related) topics of interest to students.

Lecture notes were distributed before (as a subset of full lecture notes) and after lectures, and lectures involved collaborative coding exercises with students in class without any powerpoint material. Course material here includes:

Syllabus: rough schedule and description of lectures

Lectures: pdf lecture notes with embedded code, including …


Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi Jan 2019

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …


Ice Flow Impacts The Firn Structure Of Greenland's Percolation Zone, Rosemary C. Leone Jan 2019

Ice Flow Impacts The Firn Structure Of Greenland's Percolation Zone, Rosemary C. Leone

Graduate Student Theses, Dissertations, & Professional Papers

One dimensional simulations of firn evolution neglect horizontal transport as the firn column moves down slope during burial. This approach is justifiable near Greenland's ice divide, where ice flow is near vertical, but fidelity is lost in the percolation zone where horizontal ice flow advects the firn column through climate gradients. We simulate firn evolution processes under advection conditions using a transient, thermo-mechanically coupled model for firn densification and heat transfer with various schemes for meltwater penetration and refreezing. The simulations isolate processes in synthetic runs and investigate an ice core site and four transects of Greenland’s percolation zone. The …