nyuuzyou/wikis huggingface dataset:
CSDMS 2013 annual meeting poster Jun Cheng

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Cross-shore and Vertical Distribution of Turbulence Kinetic Energy in the surf zone generated by plunging breakers=
Jun Cheng, The Universtiy of South Florida Tampa Florida, United States. jun@mail.usf.eduPing Wang, The University of South Florida Tampa Florida, United States. pwang@usf.edu
Abstract:
Breaking waves, especially plunging breakers, generate intense turbulence and is crucial in dissipating incident wave energy, suspending and transporting sediment in the surf zone. Therefore quantifying breaking-induced turbulence kinetic energy (TKE) is essential in understanding surf zone processes. Surf zone hydrodynamic data collected at the Large-scale Sediment Transport Facility (LSTF) at the U.S. Army Engineer Research and Development center were used here. One LSTF case, with irregular waves (3 s peak period), is examined here. This case resulted in dominantly plunging type of breaker. Waves and currents were measured simultaneously at 10 cross-shore locations and throughout the water column, with a sampling rate of 20 Hz. In order to separate orbital wave motion from turbulent motion, an adaptive moving average filter is developed, involving a 5-point moving average, with additional 3-point moving average at sections with more fluctuations. This adaptive moving average filter is able to maintain more wave energy as compared with the results from 7-point moving average, while resolve more turbulence energy as compared with the result from 5-point moving average.The TKE was calculated based on the resolved turbulence. Large TKE was generated at the water surface associated with wave breaking and dissipated rapidly downward. The TKE decreased nearly one order of magnitude downward within 15 cm. The TKE reached a minimum value at approximately 50%-80% of the water depth, and increased towards the bottom due to the generation of bed-induced turbulence. The TKE flux during wave crest and tough indicate that, at the bottom and middle layers of the water column, the TKE is transported dominantly onshore, while for the top layer, it is transported mostly offshore.
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CSDMS 2013 annual meeting poster Kim Picard

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Insights into late Quaternary events on the Beaufort Shelf and Slope from sea level and stratigraphic modeling=
Kim Picard, Geoscience Australia Canberra NO STATE, Australia. kim.picard@ga.gov.auPhilip Hill, Geological Survey of Canada Sidney , Canada. phill@nrcan.gc.caAndrew Wickert, University of Colorado Boulder Colorado, United States. Andrew.Wickert@colorado.edu
Abstract:
This work aims to improve the late Quaternary stratigraphic framework for the outer shelf and slope of the Beaufort Sea and to assist in the assessment of geohazards, particularly those related to slope instability. Slope failures have been identified on the upper slope, but the age and triggers of slope failure are poorly understood. Existing conceptual models of late Quaternary stratigraphy of the Beaufort shelf and slope are quite generalized and based on a poorly constrained relative sea level curve. Sea level and stratigraphic modeling are used to test the relationships between glaciation, sea level and sedimentation. The results of the work suggest that glacio-isostatic effects cause the relative sea level (RSL) curve to vary significantly across the Beaufort Shelf particularly in the cross-shelf direction. Stratigraphic modeling with a variable RSL input successfully reproduces depositional patterns in the Mackenzie Trough including distinctive highstand and lowstand wedges and a retrogradational transgressive systems tract. However on the eastern shelf, more pronounced isostatic depression is required to match the known stratigraphy, suggesting deviation from the assumed ice loads or crustal properties in the model. Two outburst floods documented to have occurred in the region would have had a marked effect on shelf edge and slope sedimentation. Modeling suggests significant progradation of the shelf edge and rapid deposition on the slope and outer shelf at lowstand and in the early stage of transgression.
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CSDMS 2013 annual meeting poster Kimberly Rogers

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Modeling floodplain dynamics: Can the Ganges-Brahmaputra Delta keep pace with 21st century sea level rise?=
Kimberly Rogers, CSDMS/INSTAAR, University of Colorado Boulder Colorado, United States. kgrogers@colorado.eduIrina Overeem, CSDMS/INSTAAR, University of Colorado Boulder Colorado, United States. irina.overeem@colorado.edu
Abstract:
Sediment delivery to low-lying coastal zones must keep pace with, if not exceed, the rate of sea level rise in order to maintain a positive surface elevation. Deltaic lowlands are vulnerable to both sea-level rise and changes in river discharge, but whether the floodplains and coastal areas will ultimately drown depends on a balance of aggradation, eustatic sea level rise and subsidence. The Ganges-Brahmaputra (G-B) Delta is an example of a densely populated coastal system that could be flooded by rapid sea level rise within the next century. Annual monsoonal river flooding and cyclonic storm surges are the principal mechanisms by which sediment is distributed across the G-B floodplain and coastal plain. Stratigraphic reconstructions show that sedimentation in the upper floodplain was more than doubled under the Early Holocene enhanced monsoonal regime, suggesting that the delta may withstand an increase in monsoonal intensity, flooding, and tropical cyclones that are currently predicted in ensemble Community Climate System Model scenarios. 
In an effort to improve predictions of climatic forcing on aggradation rates in the G-B floodplain and lower delta, direct sedimentation measurements are paired with a series of model components coupled within the CSDMS Modeling Tool (CMT). A sediment flux model, a floodplain sedimentation model and a tidal-plain sedimentation model will be linked to explore the response of the G-B river system to a future sea-level rise and changes in river discharge. Model algorithms will be validated by sedimentation data collected in 2008 and 2012 from the tidal delta (The Sundarbans National Reserve mangrove forest) and the highly cultivated fluvial-dominated delta plain. Field data will also be compared to model outputs by constraining the spatial patterns of sedimentation across the delta front. In this talk, we present initial sedimentation results and discuss controls on heterogeneous patterns of deposition in the tidal versus fluvial dominated parts of the delta. Early results from individual model components will also be discussed in an attempt to integrate current understanding of the G-B System into a numerical modeling framework.
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CSDMS 2013 annual meeting poster Laurel Larsen

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Cellular automata modeling of flow-vegetation-sediment interactions in low-gradient environments=
Laurel Larsen, University of California Berkeley Berkeley California, United States. laurel@berkeley.edu
Abstract:
Cellular automata models have gained widespread popularity in fluvial geomorphology as a tool for testing hypotheses about the mechanisms that may be essential for the formation of landscape patterning. For instance, studies of braided rivers using cellular automata modeling suggested that erodible banks are an essential characteristic for formation of the braid-plain morphology. In wetlands with emergent vegetation and complicated flow patterns, distilling the relevant, nonlinear interactions to a relatively simple set of rules that can be used in cellular automata modeling poses challenges, but the advantage of doing so lies in the ability to perform sensitivity analyses or examine system evolution over millennia. Here I show how a hierarchical modeling strategy was used to develop a cellular automata simulation of the evolution of a regular, parallel-drainage patterned landscape in the Everglades. The Ridge and Slough Cellular Automata Landscape model (RASCAL) suggested that this landscape structure is stable only over a small range of water-surface slopes (the driving variable for flow)—a result that both explains the limited distribution of low-gradient parallel-drainage systems worldwide and would likely have not been detected had a non-hierarchical CAM been used. Additional sensitivity analyses with RASCAL show how interactions between flow, vegetation, and sediment transport can lead to a wide variety of other regular and amorphous landscape patterns, depending on the relative strength of physical and biological feedbacks. Comparisons between RASCAL and well-known CAM models of braided stream dynamics raise interesting questions about the level of complexity that need to be incorporated into models of transitional (low- to high-energy) environments such as wet meadows and small/intermittent streams.
Output of a RASCAL model of the Everglades ridge and slough landscape. Elevated ridges, colonized by sawgrass, are depicted in red. Flow, which is channeled preferentially through the blue sloughs, runs from top to bottom. Recent catastrophic loss of parallel-drainage sloughs in the Everglades has been attributed to reductions in flow velocities and mean water levels.
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CSDMS 2013 annual meeting poster Leif Anderson

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=The effects of interannual climate variability on the extraction of climate estimates from glacial moraines=
Leif S. Anderson, University of Colorado Department of Geological Sciences and INSTAAR Boulder Colorado, United States.leif@colorado.eduRoe H. Gerard, University of Washington Department of Earth and Planetary Sciences Seattle Washington, United States. gerard@ess.washington.eduRobert S. Anderson, University of Colorado Department of Geological Sciences and INSTAAR Boulder Washington, United States. robert.s.anderson@colorado.edu
Abstract:
In most mountainous regions reconstructed glacial histories are the primary record of past climate and are typically based on unsorted accumulations of debris (moraines) deposited at the terminus of glaciers. Former glacier geometries— preserved as moraines and trim lines— are the primary constraint for extracting paleoclimate estimates using either equilibrium-line altitudes or numerical glacier models.
It is an implicit assumption in the glacial geology community that terminal moraines were formed by glaciers responding to the mean value of summer temperature and winter precipitation at the time of formation. In reality glacier termini oscillate around a mean glacial length even in a steady climate, defined by a constant mean and constant standard deviation. These length oscillations are driven by the alignment of more negative (positive) periods of mass balance that arise out of random year-to-year climate variability. Because glaciers that override moraines almost always destroy them, the furthest terminal moraines from the headwall during the time period of interest represent the maximum excursion of the glacier from its mean length. This implies that paleoclimate estimates based upon the furthest terminal moraine are actually maximum estimates of climate change.
We use a linearized glacier model developed by Roe and O’Neal (2009) to determine the mean length of eleven Last Glacial Maximum (LGM) glaciers in the northern Front Range, Colorado. Mean glacier lengths during the LGM were ~15% upvalley from the LGM terminal moraines. In the Colorado Front Range estimating LGM paleoclimate from the furthest terminal moraine rather than the mean length adds an extra ~1°C temperature change or an additional 25% increase in precipitation to estimate of differences from the modern climate. Furthermore, it is possible that ‘recessional’ moraines were formed by length oscillations driven by interannual variability.
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CSDMS 2013 annual meeting poster Leslie Hsu

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Data Services for Long Tail Science at the Integrated Earth Data Applications (IEDA) Data Facility=
Leslie Hsu, Lamont-Doherty Earth Observatory Palisades New York, United States. lhsu@ldeo.columbia.eduKerstin Lehnert, Lamont-Doherty Earth Observatory Palisades New York, United States. lehnert@ldeo.columbia.edu
Abstract:
IEDA (Integrated Earth Data Applications, html://www.iedadata.org) is a data facility funded through a contract with the US National Science Foundation to operate data systems and data services for solid earth geoscience data. There are many similarities between IEDA and its community of data producers and users and CSDMS and its community of model creators and users. IEDA has developed a comprehensive suite of data services that are designed to address the concerns and needs of investigators, especially researchers working in the 'Long Tail of Science' (Heidorn 2008). IEDA provides a data publication service, registering data sources (including models) with DOI to ensure their proper citation and attribution. IEDA works with publishers on advanced linkages between datasets in the IEDA repository and scientific online articles to facilitate access to the data, enhance their visibility, and augment their use and citation. IEDA also developed a comprehensive investigator support that includes tools, tutorials, and virtual or face-to-face workshops that guide and assist investigators with data management planning, data submission, and data documentation. A relationship between IEDA and CSDMS benefits the scientists from both communities by providing them with a broader range of tools and data services.
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CSDMS 2013 annual meeting poster Li Li

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Integrated modeling of coupled flow, transport, and biogeochemical processes in the natural subsurface=
Li Li, Penn State University University Park Pennsylvania, United States. lili@eme.psu.edu
Abstract:
Reactive Transport Modeling (RTM) has been developed in the past decades and used extensively to understand the coupling between fluid flow, diffusive and dispersive transport, and biogeochemical processes in the natural subsurface in a wide range of applications relevant to earth and environmental sciences. Reactive transport modeling solves conservation equations of mass, momentum, and energy. Process-based reactive transport modeling allows the regeneration of spatial and temporal propagation of tightly coupled subsurface processes at spatial scales ranging from single pores (microns) to watershed scales (kilometers). RTM can keep track of evolving porous medium properties including porosity, permeability, surface area, and mineralogical composition. In this presentation I will introduce the general framework of RTM together with its advantages and challenges. The use of RTM at different spatial and temporal scales will be illustrated using two examples. A one-dimensional chemical weathering model for soil formation in Marcellus Shale will illustrate its use in Critical Zone (CZ) processes at the time scales of tens of thousands of years. A two dimensional biogeochemical transport model will exemplify its use in understanding engineered bioremediation processes in natural, heterogeneous porous media at the time scale of months to years.
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CSDMS 2013 annual meeting poster Mark Schmeeckle

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Turbulence- and particle-resolving numerical modeling of sediment transport=
Mark Schmeeckle, Arizona State University Tempe Arizona, United States. schmeeckle@asu.edu
Abstract:
The motion of sediment in water is caused by fluid pressure gradient forces, primarily drag, on sediment grains. Turbulence-resolving experiments show significant temporal and spatial variability of fluid and sediment motion and particle forces at all stages of sediment transport. The signature of turbulence structures and their modification by sediment is apparent from incipient motion to vigorous suspension.
This presentation introduces a numerical model that combines large eddy simulation (LES) of turbulence and the distinct element method (DEM) of granular motion. The LES and DEM models are fully coupled in momentum. Information from the LES is used to specify forces on the DEM particles, and those particle forces are given in an equal and opposite direction in the filtered and discretized Navier-Stokes equations at each grid cell in the finite volume LES.
Parameterization of turbulent sediment transport processes is the basis of any well founded model of morphodynamics in fluvial and marine environments. Current parameterizations rely on a mixture of theory and empirical evidence. LES-DEM simulations can be performed in conditions that are difficult to reproduce in the laboratory and that stretch the limits of theory. It is hard to build an apparatus that can produce sediment transport under field-scale cnoidal waves, on sloping beds, with currents of arbitrary direction, and a range grain size distributions. Further, even in simple unidirectional flows only rough empirical relations exist for the critically important suspended sediment rate of entrainment.
Validation of the LES-DEM approach is essential before development of transport relations for large-scale morphodynamic models. A series of LES-DEM simulations of unidirectional flow over flat beds of medium sand, ranging from no transport, to bedload, to vigorous suspension are presented. Simulations of flat sand beds under oscillatory waves and unidirectional flow downstream of a backward-facing step are compared to laboratory measurements. Simulations over ripples and through vegetation are also presented.
Examples of some of the simulations can be previewed at the links below.
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CSDMS 2013 annual meeting poster Nathan Lyons

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2013</font>
=Landscape Evolution Models as a Public Education Tool=
Nathan Lyons, NC State University Raleigh North Carolina, United States. njlyons@ncsu.eduWalt Gurley, Nature Research Center of North Carolina Museum of Natural Science Raleigh North Carolina, United States. walt.gurley@naturalsciences.orgHelena Mitasova, NC State University Raleigh North Carolina, United States. hmitaso@ncsu.edu
Abstract:
At the Visual World Investigation Lab of the Nature Research Center, we are developing a module where museum visitors investigate geomorphic and land-use scenarios through a landscape evolution model. Visitors use touchscreen computers to select simplified inputs for the CHILD model. Model visualizations will be produced for each trial in which they run the scenario. For example, visitors can explore the impact of the percentage of impervious surfaces in a section of urbanized Raleigh that will be adjusted by scaling infiltration parameters, and how the headwaters of the Little Tennessee River would differ if the southern Appalachians were still undergoing tectonic uplift. These scenarios provide relatable experiences to visitors, an opportunity to educate them upon the science behind the scenarios, and the purpose and limitations of models. We will first develop the framework of the module to be able to accept scenarios and its inputs, including digital elevation models, such that others can contribute scenarios. This module is early in its conception, thus we will present our initial framework with the intent to elicit feedback from the community.
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