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Full-Text Articles in Physical Sciences and Mathematics
Dispersal And Population Structure Of Euchlanis Chihuahuaensis Via Anemochory In The Chihuahuan Desert, Tristan Chavez-Poeschel
Dispersal And Population Structure Of Euchlanis Chihuahuaensis Via Anemochory In The Chihuahuan Desert, Tristan Chavez-Poeschel
Open Access Theses & Dissertations
Desert ecosystems present challenges for aquatic organisms as habitats are fragmented, both in space and time; however, diapausing stages of rotifers can travel hundreds of kilometers during wind events. I used the rotifer Euchlanis chihuahuaensis as a model species to investigate the influence of wind dispersal on gene flow and population genetics in Chihuahuan Desert populations. I hypothesized that anemochory facilitates gene flow from source populations in the Northern Chihuahuan Desert in Mexico and the western United States to habitats in the Trans-Pecos region via delineated wind corridors. To test this hypothesis, the genetic diversity of populations from both inside …
Understanding The Chemical Weathering Rate And Element Mobility Of Soils: Using U-Series, Nd-Sr Isotopes Ree And Quantum Chemistry Computational Simulation, Jiye Guo
Open Access Theses & Dissertations
Soil played as the central role in the interaction of biosphere, hydrosphere, lithosphere and atmosphere and is the heart of earth's critical zone study. The weathering and element mobility of soils have drawn considerable attention in soil studies since the complexity of these processes and the critical influence towards the earth and humanity, e.g., the global carbon cycles and fertilization. However, the interaction between soils and various factors including precipitation, bedrock ages, altitude is not well understood. Basse-Terre Island at French Guadeloupe, a small volcanic tropical island that has steep environmental gradients of bedrock ages, topography and precipitation, can be …
Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea
Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea
Open Access Theses & Dissertations
Dry deposition significantly affects evolution of the critical zone by nutrient supply and contributing to soil genesis. Dust influx and cycling in soils are difficult to quantify because dust sources can be chemically similar to local soils. White Sands, New Mexico, emits gypsum dust with a unique chemical and isotopic signature, providing an opportunity to investigate dust deposition and its movement in soils. This study evaluated the mobility of White Sands dust particles in the critical zone at White Mountain, New Mexico, a highland 100 km downwind. Four soil profiles were collected over limestone, igneous, mixed limestone and dolostone, and …
Uranium-Series And Strontium Isotope Ratios In Soils From Basse-Terre Island, French Guadeloupe: Insights For Rapid Soil Formation And Impact Of Dust In A Tropical Volcanic Setting, Yvette Pereyra
Open Access Theses & Dissertations
Chemical weathering of silicate rocks generates soils that contain mineral nutrients, sustain ecosystems, modify water chemistry in the hydrosphere, and regulate the global carbon cycle. Understanding the timescales of soil formation and sources of soil mineral nutrients has great implications for securing the future of agriculture and food production. However, few tools are currently available to directly quantify the rates of chemical weathering and timescales of soil formation. Uranium-series isotopes fractionate during chemical weathering and the activity ratios of (234U/238U), (230Th/238U), (238U/232Th) and (230Th/232Th) have great potential to constrain the rates and timescales of chemical weathering and soil formation in …
Heavy Metal Pollution In The Paso Del Norte Region:Historical Reconstruction And Source Interpretation, Eugenia G. Shekhter
Heavy Metal Pollution In The Paso Del Norte Region:Historical Reconstruction And Source Interpretation, Eugenia G. Shekhter
Open Access Theses & Dissertations
A unique and complex situation of heavy metal pollution arose in the El Paso del Norte region, one of the largest and oldest metropolitan areas on the US-Mexican border. This region with its complex topography is home to more than 2.2 million people sharing the same environment. Although many studies have been conducted in the region to identify the sources of environmental contamination, the cumulative history of heavy metal pollution is still incomplete. In order to identify the patterns of heavy metal dispersion and to test the hypothesis that the American Smelting and Refining Company (ASARCO) was a considerable contributor …
Analysis And Modeling Of Dust Event Data From El Paso, Texas, Nancy Ivette Rivera Rivera
Analysis And Modeling Of Dust Event Data From El Paso, Texas, Nancy Ivette Rivera Rivera
Open Access Theses & Dissertations
Wind erosion is a dynamic physical process that leads to environmental degradation when strong winds blow on loose, dry, bare soils, creating dust events that can impact human health, visibility and air quality. Since 1932, more than two thousand dust event days were recorded at El Paso, averaging 25 per year. This research analyzes and models data on dust events in the El Paso/Juarez metropolitan area for better understanding of their effects. The meteorological characteristics of these events are analyzed for variables such as the frequency, visibility, and average wind speeds associated with convective and non-convective events. These variables are …
Analysis Of Aerosol Particle Size Distributions Observed During Aerose V Campaign, Mariana Guereque
Analysis Of Aerosol Particle Size Distributions Observed During Aerose V Campaign, Mariana Guereque
Open Access Theses & Dissertations
The African continent is the principal contributor of mineral aerosols into the atmosphere. It is also a significant source of carbonaceous aerosols resulting from rampant biomass burning activities. Both aerosol types have a profound impact on climate change and are an important factor in climate modeling, regional weather forecasting, as well as health-impact studies. Due to their importance, it is beneficial to characterize the transport and evolution of these aerosols from their origins in Africa, across the Atlantic Ocean and into the Americas. In-situ aerosol number distributions were collected during the 2009 Aerosols and Ocean Science Expeditions (AEROSE) V campaign, …
Evaluating Suspended Dust Particulate Matter From Anthropogenically - Altered Lands, Roberto Velarde
Evaluating Suspended Dust Particulate Matter From Anthropogenically - Altered Lands, Roberto Velarde
Open Access Theses & Dissertations
Substantial dust loads are transported from drylands including the Saharan, Asian, and Chihuahuan Desert deposits by localized to planetary-scale processes to nearby and distal sites. These dusts may carry harmful constituents. To evaluate dust movement patterns and characteristics relative to carried constituents, three studies are presented comprising (A) Localized displacement of uranium and progeny radionuclides from high-grade uranium ore storage piles at Peña Blanca, Chihuahua, Mexico; (B) Long-distance transport of plutonium via Saharan and Asian aeolian pathways; and (C) Dust movement patterns in military maneuvering and non-maneuvering areas at White Sands Missile Range (WSMR), New Mexico. Study (A) evaluated surface …