Matching Items (3)
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- All Subjects: Meteorology
- Creators: Balling, Robert
Description
The North American Monsoon (NAM) is a late summer increase in precipitation fundamentally caused by a wind shift that is evident in the southwestern United States and northwest Mexico from approximately June-August. Increased precipitation during these months bring an increased regional threat from heavy rains, blowing dust, and damaging storms. (Adams and Comrie 1997). Researchers in Phoenix, AZ theorized that using surface dewpoint measurements was an objective way to officially mark the start of the NAM in Phoenix, AZ (and Tucson, AZ). Specifically, they used three consecutive days at or above a certain dewpoint temperature (Franjevic 2017). The justification for this method was developed by Reitan (1957) who established that 25.4mm (1.00”) of integrated precipitable water (IPW) was a sufficient threshold to create storm activity in the NAM region. He also determined (Reitan 1963) that a strong correlation existed between (IPW) and surface dewpoint (Td), whereas, Td could be used as a proxy to determine IPW.
I hypothesize that the correlation coefficients between IPW and Td will be greatest when using seasonal mean averages of IPW and Td, and they will decrease with shortened mean timescales (from seasonal to three-days). Second, I hypothesize that there is a unique relationship between IPW/Td that may signal monsoon onset. To conduct this study, I used the North American Regional Reanalysis (NARR) dataset (1979-2015). For ten locations in the Southwest, I conducted a series of statistical analyses between IPW, Td, and accumulated precipitation. I determined that there is a correlation between the two as set forth by Reitan (1963) as well as (Benwell 1965; Smith 1966; Ojo 1970). However, from the results I concluded this relationship is highly variable, spatially and temporally. Additionally, when comparing the three-hour, three-day, and the weekly mean measurements, I can conclude that, for my study, timescale averaging did enhance the IPW/Td relationship from three-hour to weekly as expected. The temporal and spatial evolution of the IPW/Td correlation as presented in this thesis may provide a framework for future research that reevaluates the NAM’s domain and the associated methods for determining its onset.
I hypothesize that the correlation coefficients between IPW and Td will be greatest when using seasonal mean averages of IPW and Td, and they will decrease with shortened mean timescales (from seasonal to three-days). Second, I hypothesize that there is a unique relationship between IPW/Td that may signal monsoon onset. To conduct this study, I used the North American Regional Reanalysis (NARR) dataset (1979-2015). For ten locations in the Southwest, I conducted a series of statistical analyses between IPW, Td, and accumulated precipitation. I determined that there is a correlation between the two as set forth by Reitan (1963) as well as (Benwell 1965; Smith 1966; Ojo 1970). However, from the results I concluded this relationship is highly variable, spatially and temporally. Additionally, when comparing the three-hour, three-day, and the weekly mean measurements, I can conclude that, for my study, timescale averaging did enhance the IPW/Td relationship from three-hour to weekly as expected. The temporal and spatial evolution of the IPW/Td correlation as presented in this thesis may provide a framework for future research that reevaluates the NAM’s domain and the associated methods for determining its onset.
ContributorsPanhans, Paul T (Author) / Cerveny, Randall (Thesis advisor) / Balling, Robert (Committee member) / Krahenbuhl, Daniel (Committee member) / Arizona State University (Publisher)
Created2017
Description
Meteorology is an uncommon term rarely resonating through elementary classrooms. However, it is a concept found in both fourth and sixth grade Arizona science standards. As issues involving the environment are becoming more pertinent, it is important to study and understand atmospheric processes along with fulfilling the standards for each grade level. This thesis project teaches the practical skills of weather map reading and weather forecasting through the creation and execution of an after school lesson with the aide of seven teen assistants.
ContributorsChoulet, Shayna (Author) / Walters, Debra (Thesis director) / Oliver, Jill (Committee member) / Balling, Robert (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12
Description
This study examines the linkage between surface level ozone and planetary boundary layer meteorological variables in the Phoenix Metropolitan region during the summer North American Monsoon period for years 2010 through 2020. Data used in this study was obtained and derived from both 1200 UTC radiosonde observations launched from the Phoenix National Weather Service office, and 8-hour average ozone concentration measurements from Maricopa County monitoring stations. Specific boundary layer meteorological variables examined in this study included inversion temperature, mixing level pressure, mixing level height, and the surface level variables of temperature, dew point temperature, pressure, wind speed, and meridional and zonal wind directions. The daily maximum, 8-hour average ozone concentrations among all Maricopa County monitoring stations were used in this study. To determine ozone’s linkage to meteorological variables, normality tests, determination of Pearson product moment correlation coefficient and/or the Spearman rank correlation coefficient, and the discriminative Student’s two-sided t-test statistic between ozone exceedance and non-exceedance days were used. Statistically significant coefficients indicate weak negative correlations between surface level ozone and surface level pressure, and mixing level pressure, and weak positive correlations between surface level ozone and surface level temperature, surface level zonal wind direction, mixing level height, and inversion temperature. These correlations were linear for surface level pressure, surface level temperature, and inversion temperature. The two-sided Student’s t-test statistic indicates a significant difference in the mean on ozone exceedance and non-exceedance days for surface level temperature, and the upper-air variables of mixing level height, mixing level pressure, and inversion temperature. Both correlations and differences in the mean of upper-air variables showed statistically significant results. These findings suggest that further research should be completed to determine the forecasting ability of morning sounding analyses on surface level ozone in locations exhibiting similar emissions and geographic features as the Phoenix Valley.
ContributorsLopez, David (Author) / Cerveny, Randall (Thesis director) / Balling, Robert (Committee member) / Barrett, The Honors College (Contributor) / School of Music, Dance and Theatre (Contributor) / Department of Physics (Contributor) / School of Geographical Sciences and Urban Planning (Contributor)
Created2023-05