Matching Items (6)
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- All Subjects: Climate
- Creators: School of Geographical Sciences and Urban Planning
- Creators: Arrowsmith, Ramon
- Creators: Davis, Jonathan
- Resource Type: Text
Description
The Himalaya are the archetypal example of a continental collision belt, formed by the ongoing convergence between India and Eurasia. Boasting some of the highest and most rugged topography on Earth, there is currently no consensus on how climatic and tectonic processes have combined to shape its topographic evolution. The Kingdom of Bhutan in the eastern Himalaya provides a unique opportunity to study the interconnections among Himalayan climate, topography, erosion, and tectonics. The eastern Himalaya are remarkably different from the rest of the orogen, most strikingly due to the presence of the Shillong Plateau to the south of the Himalayan rangefront. The tectonic structures associated with the Shillong Plateau have accommodated convergence between India and Eurasia and created a natural experiment to test the possible response of the Himalaya to a reduction in local shortening. In addition, the position and orientation of the plateau topography has intercepted moisture once bound for the Himalaya and created a natural experiment to test the possible response of the range to a reduction in rainfall. I focused this study around the gently rolling landscapes found in the middle of the otherwise extremely rugged Bhutan Himalaya, with the understanding that these landscapes likely record a recent change in the evolution of the range. I have used geochronometric, thermochronometric, and cosmogenic nuclide techniques, combined with thermal-kinematic and landscape evolution models to draw three primary conclusions. 1) The cooling histories of bedrock samples from the hinterland of the Bhutan Himalaya show a protracted decrease in erosion rate from the Middle Miocene toward the Pliocene. I have attributed this change to a reduction in shortening rates across the Himalayan mountain belt, due to increased accommodation of shortening across the Shillong Plateau. 2) The low-relief landscapes of Bhutan were likely created by backtilting and surface uplift produced by an active, blind, hinterland duplex. These landscapes were formed during surface uplift, which initiated ca. 1.5 Ma and has totaled 800 m. 3) Millennial-scale erosion rates are coupled with modern rainfall rates. Non-linear relationships between topographic metrics and erosion rates, suggest a fundamental difference in the mode of river incision within the drier interior of Bhutan and the wetter foothills.
ContributorsAdams, Byron A (Author) / Whipple, Kelin X (Thesis advisor) / Hodges, Kip V (Thesis advisor) / Heimsath, Arjun M (Committee member) / Arrowsmith, Ramon (Committee member) / Hurtado, Jose M (Committee member) / Arizona State University (Publisher)
Created2014
Description
Urban areas produce an urban heat island (UHI), which is manifest as warmer temperatures compared to the surrounding and less developed areas. While it is understood that UHI's are warmer than their surrounding areas, attributing the amount of heat added by the urban area is not easily determined. Current generation modeling systems require diurnal anthropogenic heating profiles. Development of diurnal cycle profiles of anthropogenic heating will help the modeling community as there is currently no database for anthropogenic heating profiles for cities across the United States. With more accurate anthropogenic heating profiles, climate models will be better able to show how humans directly impact the urban climate. This research attempts to create anthropogenic heating profiles for 61 cities in the United States. The method used climate, electricity, natural gas, and transportation data to develop anthropogenic heating profiles for each state. To develop anthropogenic heating profiles, profiles are developed for buildings, transportation, and human metabolism using the most recently available data. Since utilities are reluctant to release data, the building energy profile is developed using statewide electricity by creating a linear regression between the climate and electricity usage. A similar method is used to determine the contribution of natural gas consumption. These profiles are developed for each month of the year, so annual changes in anthropogenic heating can be seen. These profiles can then be put into climate models to enable more accurate urban climate modeling.
ContributorsMilne, Jeffrey (Author) / Georgescu, Matei (Thesis director) / Sailor, David (Committee member) / Brazel, Anthony (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Geographical Sciences and Urban Planning (Contributor)
Created2014-05
Description
The Great Plains region of the central United States and southern Canada is a promising location for wind energy resource development. Wind energy site assessments and forecasts can benefit from better understanding the variability that may result from several teleconnections affecting North America. This thesis investigates how the El Niño/Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the Pacific/North American Pattern (PNA) impact mean monthly wind speeds at 850 hPa over the Great Plains. Using wind speeds from the NCAR/NCEP Reanalysis 1, correlations were computed between the mean monthly wind speeds and average monthly teleconnection index values. A difference of means test was used to compute the change in wind speeds between the positive and negative phases of each index. ENSO was not found to have a significant impact on wind speeds, while the NAO and PNA patterns weakly affected wind speeds. The NAO index was positively (negatively) correlated with wind speeds over the northern (southern) plains, while the PNA index was negatively correlated with wind speeds over most of the plains. Even a small change in wind speed can have a large effect on the potential power output, so the effects of these teleconnections should be considered in wind resource assessments and climatologies.
ContributorsOrdonez, Ana Cristina (Author) / Cerveny, Randall (Thesis director) / Svoma, Bohumil (Committee member) / Balling, Robert (Committee member) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor)
Created2013-05
Description
The Phoenix area, is known for suburban sprawl which did not happen in isolation but was the result of many external factors. It was not just large environmental and cultural factors that changed over time, but the actual physical characteristics of sprawl that have changed from community to community over the decades. Characteristics like physical size of houses and lot size, along with changes in the residential and commercial design and building style have changed from around the 1950s to present day, with homes being larger and covering more of each parcel. These characteristics were analyzed in 21 communities in the Phoenix area that were built from 1950 to 2019 to find how these characteristics have changed over time. While the issue of sprawl will never fully go away, by learning what the characteristics are that make up the definition of sprawl, stakeholders like cities, planners, and developers will have better knowledge for planning for tomorrow.
ContributorsGallegos, Jairus Donald (Author) / King, David (Thesis director) / Davis, Jonathan (Committee member) / School of Geographical Sciences and Urban Planning (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Rivers in steep mountainous landscapes control how, where, and when signals of base-level fall are transmitted to the surrounding topography. In doing so rivers play an important role in determining landscape evolution in response to external controls of tectonics and climate. However, tectonics and climate often covary and understanding how they influence landscape evolution remains a significant challenge. The Hawaiian Islands, where tectonics are minimized but climate signals are amplified, provide an opportunity to better understand how signals of climate are recorded by landscapes. Focusing on the Hawaiian Islands, I examine (1) how variability in rock mass properties and thresholds in sediment mobility determine where waterfalls form or stall along the Nāpali coast of Kauaʻi, (2) I then extend these findings to other volcanoes to test if observed physical limits in flood size, climate, and volcano gradient can determine where waterfalls form, and (3) I explore how thresholds in river incision below waterfalls limit information about the influence of climate on river incision rates. Findings from this analysis show that waterfalls form or stall where the maximum unit stream power is at or below a critical unit stream power for bedrock river incision. Climate appears to have little effect in determining where these conditions are met but where waterfalls stall or form does record information about discharge-area scaling for global maximum observed floods. Below waterfalls the maximum incision depth for rivers on the island of Kauaʻi (which formed ~ 4-5 million years ago) is approximately proportional to the inverse square root of mean annual rainfall. Though maximum river incision depths for some of the younger volcanoes do not exhibit the same dependency on mean annual rainfall rates they are comparable to the maximum incision depths observed on Kauaʻi even though they are a quarter to one-tenth the age of Kauaʻi. Importantly, these patterns of incision can be explained by thresholds in sediment mobility as recorded by river longitudinal profiles and indicate that the Hawaiian Islands are dominated by threshold conditions where signals of climate are recorded in the topography through controls on incision depth but not incision rates.
ContributorsRaming, Logan Wren (Author) / Whipple, Kelin X (Thesis advisor) / Arrowsmith, Ramon (Committee member) / Heimsath, Arjun M. (Committee member) / DeVecchio, Duane E. (Committee member) / Schmeeckle, Mark (Committee member) / Arizona State University (Publisher)
Created2022
Description
The Barrett Honors College website contains a lot of information that isn’t easily accessible by Honors Students. Many honors students have trouble finding the correct information they need. Important information is scattered all over the website making it difficult for honors students to find and understand the information they need. One example of this is the requirements for Lower and Upper Division credit. This website displays the upper and lower division credit needed for a student to graduate from the honors college via a noninteractive flowchart. Many high school seniors find it difficult to understand the mundane flowchart outlining the required honors credit that is required for graduating from Barrett at Arizona State University. Also, it is confusing for many transfer students with unique circumstances to determine the necessary requirements for them to graduate as a Barrett student.
These difficult flowcharts and confusing websites have a huge impact on a student’s ability to adequately receive the information they need and, in the end, can have a negative impact on their ultimate decision when deciding if Barrett is right for them. A better user experience can be a more effective way of displaying information to students. A better design that allows to user more interaction would allow for the user to better understand the information they are presented. Instead of a monotone flowchart displaying the requirements necessary to graduate with honors status, A web application where a user can input their information and get an output of the necessary requirements tailored to the unique circumstance would be more informative, useful, and easier to use. The web app would take information such as a student’s year, whether it be an incoming freshman or transfer student, and their current and previous course credit to determine the specific number of honors credits, The Human Event courses, and Thesis project required for this user to complete the requirements for Barrett Honors College. This application would give the user a better understanding of what is required of them and in turn lead to a better user experience.
These difficult flowcharts and confusing websites have a huge impact on a student’s ability to adequately receive the information they need and, in the end, can have a negative impact on their ultimate decision when deciding if Barrett is right for them. A better user experience can be a more effective way of displaying information to students. A better design that allows to user more interaction would allow for the user to better understand the information they are presented. Instead of a monotone flowchart displaying the requirements necessary to graduate with honors status, A web application where a user can input their information and get an output of the necessary requirements tailored to the unique circumstance would be more informative, useful, and easier to use. The web app would take information such as a student’s year, whether it be an incoming freshman or transfer student, and their current and previous course credit to determine the specific number of honors credits, The Human Event courses, and Thesis project required for this user to complete the requirements for Barrett Honors College. This application would give the user a better understanding of what is required of them and in turn lead to a better user experience.
ContributorsGandhe, Nikhil (Author) / Menees, Jodi (Thesis director) / Barnett, Jessica (Committee member) / Davis, Jonathan (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05