Matching Items (4)
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- All Subjects: Climatic changes
- Genre: Academic theses
- Creators: Bolin, Bob
- Creators: Herrmann, Marcus
Description
The numerical climate models have provided scientists, policy makers and the general public, crucial information for climate projections since mid-20th century. An international effort to compare and validate the simulations of all major climate models is organized by the Coupled Model Intercomparison Project (CMIP), which has gone through several phases since 1995 with CMIP5 being the state of the art. In parallel, an organized effort to consolidate all observational data in the past century culminates in the creation of several "reanalysis" datasets that are considered the closest representation of the true observation. This study compared the climate variability and trend in the climate model simulations and observations on the timescales ranging from interannual to centennial. The analysis focused on the dynamic climate quantity of zonal-mean zonal wind and global atmospheric angular momentum (AAM), and incorporated multiple datasets from reanalysis and the most recent CMIP3 and CMIP5 archives. For the observation, the validation of AAM by the length-of-day (LOD) and the intercomparison of AAM revealed a good agreement among reanalyses on the interannual and the decadal-to-interdecadal timescales, respectively. But the most significant discrepancies among them are in the long-term mean and long-term trend. For the simulations, the CMIP5 models produced a significantly smaller bias and a narrower ensemble spread of the climatology and trend in the 20th century for AAM compared to CMIP3, while CMIP3 and CMIP5 simulations consistently produced a positive trend for the 20th and 21st century. Both CMIP3 and CMIP5 models produced a wide range of the magnitudes of decadal and interdecadal variability of wind component of AAM (MR) compared to observation. The ensemble means of CMIP3 and CMIP5 are not statistically distinguishable for either the 20th- or 21st-century runs. The in-house atmospheric general circulation model (AGCM) simulations forced by the sea surface temperature (SST) taken from the CMIP5 simulations as lower boundary conditions were carried out. The zonal wind and MR in the CMIP5 simulations are well simulated in the AGCM simulations. This confirmed SST as an important mediator in regulating the global atmospheric changes due to GHG effect.
ContributorsPaek, Houk (Author) / Huang, Huei-Ping (Thesis advisor) / Adrian, Ronald (Committee member) / Wang, Zhihua (Committee member) / Anderson, James (Committee member) / Herrmann, Marcus (Committee member) / Arizona State University (Publisher)
Created2013
Description
The manner in which land and water are used and managed is a major influencing factor of global environmental change. Globally, modifications to the landscape have drastically transformed social and ecological communities. Land and water management practices also influences people's vulnerability to hazards. Other interrelated factors are compounding problems of environmental change as a result of land and water use changes. Such factors include climate change, sea level rise, the frequency and severity of hurricanes, and increased populations in coastal regions. The implication of global climate change for small islands and small island communities is especially troublesome. Socially, small islands have a limited resource base, deal with varying degrees of insularity, generally have little political power, and have limited economic opportunities. The physical attributes of small islands also increase their vulnerability to global climate change, including limited land area, limited fresh water supplies, and greater distances to resources. The focus of this research project is to document place-specific - and in this case island-specific - human-environmental interactions from a political ecology perspective as a means to address local concerns and possible consequences of global environmental change. The place in which these interactions are examined is the barrier island and village of Ocracoke, North Carolina. I focus on the specific historical-geography of land and water management on Ocracoke as a means to examine relationships between local human-environmental interactions and environmental change.
ContributorsPompeii, Brian J (Author) / Bolin, Bob (Thesis advisor) / Boone, Christopher (Committee member) / Lukinbeal, Christopher (Committee member) / Arizona State University (Publisher)
Created2014
Description
Climate change poses a threat to the emotional well-being and livelihood strategies of individuals in biophysically vulnerable communities. While the biophysical effects and possibilities of climate change are well-documented, understanding the emotional impacts on individuals in these communities is an avenue of research that requires more exploration. Using an ethnographic approach, this study analyzes the emotional responses of individuals, first in three biophysically vulnerable communities in the United States, and second, in island communities. Study sites in the United States include Mobile, Alabama; Kodiak, Alaska; and Phoenix, Arizona, each of which have different vulnerabilities to the effects of climate change. Internationally, we conducted research in Viti Levu, Fiji; Nicosia, Cyprus; Wellington, New Zealand; and London, England. Using the 2014 Global Ethnohydrology Study Protocol respondents were asked about their emotional responses to the current effects of climate change, the effects of climate change on livelihoods in their area, and the effects of climate change on the younger generation. Using cross-cultural data allows for a broader understanding of emotional distress and wellbeing in response to climate change in areas with similar expected climate change outcomes, although with different levels of biophysical vulnerability, as well as understanding emotional distress and wellbeing in areas with different expected climate change outcomes, and similar levels of biophysical vulnerability. Results from this research can be used to understand possible mental health outcomes, the possibilities for political activism, and how to create mitigation strategies that resonate with local community members.
ContributorsDu Bray, Margaret V (Author) / Wutich, Amber (Thesis advisor) / BurnSilver, Shauna (Thesis advisor) / Bolin, Bob (Committee member) / Arizona State University (Publisher)
Created2017
Description
This study uses the Weather Research and Forecasting (WRF) model to simulate and predict the changes in local climate attributed to the urbanization for five desert cities. The simulations are performed in the fashion of climate downscaling, constrained by the surface boundary conditions generated from high resolution land-use maps. For each city, the land-use maps of 1985 and 2010 from Landsat satellite observation, and a projected land-use map for 2030, are used to represent the past, present, and future. An additional set of simulations for Las Vegas, the largest of the five cities, uses the NLCD 1992 and 2006 land-use maps and an idealized historical land-use map with no urban coverage for 1900.
The study finds that urbanization in Las Vegas produces a classic urban heat island (UHI) at night but a minor cooling during the day. A further analysis of the surface energy balance shows that the decrease in surface Albedo and increase effective emissivity play an important role in shaping the local climate change over urban areas. The emerging urban structures slow down the diurnal wind circulation over the city due to an increased effective surface roughness. This leads to a secondary modification of temperature due to the interaction between the mechanical and thermodynamic effects of urbanization.
The simulations for the five desert cities for 1985 and 2010 further confirm a common pattern of the climatic effect of urbanization with significant nighttime warming and moderate daytime cooling. This effect is confined to the urban area and is not sensitive to the size of the city or the detail of land cover in the surrounding areas. The pattern of nighttime warming and daytime cooling remains robust in the simulations for the future climate of the five cities using the projected 2030 land-use maps. Inter-city differences among the five urban areas are discussed.
The study finds that urbanization in Las Vegas produces a classic urban heat island (UHI) at night but a minor cooling during the day. A further analysis of the surface energy balance shows that the decrease in surface Albedo and increase effective emissivity play an important role in shaping the local climate change over urban areas. The emerging urban structures slow down the diurnal wind circulation over the city due to an increased effective surface roughness. This leads to a secondary modification of temperature due to the interaction between the mechanical and thermodynamic effects of urbanization.
The simulations for the five desert cities for 1985 and 2010 further confirm a common pattern of the climatic effect of urbanization with significant nighttime warming and moderate daytime cooling. This effect is confined to the urban area and is not sensitive to the size of the city or the detail of land cover in the surrounding areas. The pattern of nighttime warming and daytime cooling remains robust in the simulations for the future climate of the five cities using the projected 2030 land-use maps. Inter-city differences among the five urban areas are discussed.
ContributorsKamal, Samy (Author) / Huang, Huei-Ping (Thesis advisor) / Anderson, James (Thesis advisor) / Herrmann, Marcus (Committee member) / Calhoun, Ronald (Committee member) / Myint, Soe (Committee member) / Arizona State University (Publisher)
Created2015