Artificial Light At Night (ALAN)
Randall Walker, Kelly Ramirez
The University of Texas at El Paso
The University of Texas at El Paso
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Artificial light at night (ALAN) illuminates the night sky allowing humans to extend the day length for work, socializing and cultural activities. While ALAN is beneficial to our developing society, it takes a significant toll on biological organisms that use the moon and stars for cues. Negatively affecting the circadian rhythm of biological organisms, anthropogenic activity increase in areas that originally lacked light, and the amount of short or long pulses of light intensity. Previously research has shown that insects, birds, some mammals and even plants are significantly influenced by ALAN. Yet, there is a lack of understanding how ALAN varies among different classes of microorganisms, if or how Alan effects microorganisms better as a whole or individual species, how ALAN influences a plants fitness with seasonal or human changes, behavioral, physiological, or metabolic responses, and how spatial variations of light exposure affects microbial activity. Soil biodiversity, including bacteria, archaea, fungi, and other eukaryotes largely colonize the top 5-10cm of soils and are a significant contributor to ecosystem processes like nutrient cycling, supporting primary productivity, and water filtration. In dryland systems, this layer of soil biodiversity is congregated in soil crusts (or biocrusts or cryptobiotic soils). Since soils contain microbes with different types of metabolisms, previous work has shown that some microbes cue to light, this research will explore if ALAN can impact microbial community diversity at local, regional, or global scales. To address this question I will use 3 different microbial data sets: (1) central park, NYC; (2) tall-grass prairie in the midwestern USA, and (3) a global sample set ranging from Alaska to Antarctica.
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Multi-Physics Based Modelling Approach to Understand Plunging Flows in Scaled-Down Geometrically Similar Laboratory Experiment and Field–Scale Bedrock Rivers Using Eddy-Resolving Models
Jayanga T. Samarasinghe, Laura V. Alvarez
The University of Texas at El Paso
The University of Texas at El Paso
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Fluid flow-induces incisions in bedrock rivers have a significant role in landscape evolution. Yet, the influence of flows in bedrock rivers for incision mechanisms remains unclear. Field experiments conducted in the Fraser River suggest that these incisions are caused by plunging flows. Plunging flows are complex fluid flows often observed in bedrock rivers with constriction-pool-widening (CPW) channel morphology. These flows associated velocity inversions result in shear stresses at bed, responsible for sediment transport, and subsequent incisions. However, field experiments are complex and uncertain while laboratory experiments showed distortions in flow dynamics. Numerical modeling serves as a tool to address this issue. However, neither field-laboratory experiments nor numerical models can fully capture natural processes due to limitations and simplifications. Therefore, the combination of both would help to have a better understanding of the flow processes. Recently, Computational Fluid Dynamics (CFD) models have emerged as a method for accurately simulating turbulent flows. The present study is conducted to understand complex fluid dynamics in plunging flows, using CFD models. The computational domains for field-scale and laboratory experiment model were constructed from a structured hexagonal grid mesh. LES technique was employed to resolve anisotropic turbulence above a spatial filter, and pimpleFoam was used as the incompressible solver algorithm for velocity-pressure coupling. The boundary conditions imposed for the models at riverbed and sidewalls in the computational domain are set as non-slip and integrated with the rough-wall function, water surface is set as slip, and the inlet with velocities corresponds to high and low flows. CFD simulations show that CPW morphology and discharge govern the formation of plunging flows and velocity inversions. This velocity inversion causes high bed shear stresses, leading to erosion and incisions. Moreover, the developed CFD model can be used as a benchmark for understanding complex fluid dynamics and flow processes, in bedrock rivers.
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Preservation and Educational Development Of Dinosaur Tracks At Mt. Cristo Rey, Sunland Park, NM
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Alan Espino, Jason Ricketts
The University of Texas at El Paso The Community-Driven Inclusive Excellence and Leadership Opportunities in the Geosciences (CIELO-G) project aims to transform our geoscience community culture by intentionally engaging and interacting with our community. The primary motivation for this project is to promote, preserve, and contribute new data for this site. This study focuses on the Anapra Sandstone found inMt. Cristo Rey which is located in Sunland Park, New Mexico. The Anapra formation is orange to brown in color and consists of thin to massively bedded quartz sandstone with interlaminations of shale; it is early Cretaceous in age and about 60m thick. Dinosaur track sites and swimming traces of ornithopods, theropods, and ankylosaurs were discovered here within the past 20 years. This discovery eventually led to the donation of a land parcel to Insights Science Discovery for the purposes of educational outreach and preservation. Currently, various track sites have undergone notable deterioration due to both natural processes and the increase in human presence. Preservation of these tracks began by testing potential concrete sealants and dyes on the top part of the Anapra Sandstone where most of the tracks are found. There are three different concrete sealants and several dye colors being currently tested, two water-based and one solvent based. Thin sections of this unit will also be made in order to better understand the cement and porosity of this sandstone. Highresolution imaging from a drone survey will also be used to create a 3D model and DEM of the most prominent track site location. This will be used as an educational tool, and to monitor any subtle changes at this site. The preservation of these track sites in collaboration with a community partner, Insights Science Discovery, is centered on the CIELO-G goals of geoscience education and outreach in order to create meaningful community impacts.
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