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Automated Low-cost Instrument for Measuring Total Column Ozone

Description: Networks of ground-based and satellite borne instruments to measure ultraviolet (UV) sunlight and total column ozone have greatly contributed to an understanding of increased amounts of UV reaching the surface of the Earth caused by stratospheric ozone depletion. Increased UV radiation has important potential effects on human health, and agricultural and ecological systems. Observations from these networks make it possible to monitor total ozone decreases and to predict ozone recovery trends due to global efforts to curb the use of products releasing chemicals harmful to the ozone layer. Thus, continued and expanded global monitoring of ozone and UV is needed. However, existing automatic stratospheric ozone monitors are complex and expensive instruments. The main objective of this research was the development of a low-cost fully automated total column ozone monitoring instrument which, because of its affordability, will increase the number of instruments available for ground-based observations. The new instrument is based on a high-resolution fiber optic spectrometer, coupled with fiber optics that are precisely aimed by a pan and tilt positioning mechanism and with controlling programs written in commonly available software platforms which run on a personal computer. This project makes use of novel low-cost fiber optic spectrometer technology. A cost advantage is gained over available units by placing one end of the fiber outdoors to collect sunlight and convey it indoors, thereby allowing the spectrometer and computer to be placed in a controlled environment. This reduces the cost of weatherproofing and thermal compensation. Cost savings also result from a simplified sun targeting system, because only a small pan and tilt device is required to aim the lightweight fiber optic ends. Precision sun-targeting algorithms, optical filter selection, and software to derive ozone from spectral measurements by the spectrometer are a major contribution of this project. This system is a flexible platform ...
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Date: May 2006
Creator: Nebgen, Gilbert Bernard
Partner: UNT Libraries

Executive Order 2010-06 : Governor's Policy on Climate Change

Description: WHEREAS, Arizona was a founding member of the Western Climate Initiative (WCI) in February 2007; WHEREAS, the United States Environmental Protection Agency (USEPA) finalized regulations mandating GHG reporting, effective on December 29, 2009,...WHEREAS, it is critical that Arizona stay informed of and influence any federal regulation and legislation relating to climate change and capping of GHG emission...NOW, THEREFORE, I, Janice K. Brewer, Governor of the State of Arizona,...hereby order and direct as follows: 4. The Climate Change Oversight Group ("Group") is established and charged with monitoring the continued work of the WCI...11. The Group and this Executive Order shall expire December 31, 2012
Date: October 2010
Creator: Brewer, Janice K.
Partner: UNT Libraries

Environmental Effects of Ozone Depletion: 1994 Assessment

Description: A change in the composition of the stratosphere becomes relevant to society only if it has noticeable effects. This places the assessment of effects in a pivotal role in the problem of ozone depletion. Decreases in the quantity of total-column ozone, as now observed in many places, tend to cause increased penetration of solar UV-B radiation (290-315 nm) to the Earth's surface. UV-B radiation is the most energetic component of sunlight reaching the surface. It has profound effects on human health, animals, plants, microorganisms, materials and on air quality. Thus any perturbation which leads to an increase in UV-B radiation demands careful consideration of the possible consequences. This is the topic of the present assessment made by the Panel on Environmental Effects of Ozone Depletion.
Date: November 1994
Creator: United Nations Environment Programme
Partner: UNT Libraries

Ozone

Description: In the stratosphere, ozone is created primarily by ultraviolet radiation. When high-energy ultraviolet rays strike ordinary oxygen molecules (O2), they split the molecule into two single oxygen atoms, known as atomic oxygen. A freed oxygen atom then combines with another oxygen molecule to form a molecule of ozone. There is so much oxygen in our atmosphere, that these high-energy ultraviolet rays are completely absorbed in the stratosphere.
Date: 2002
Creator: NASA Earth Observatory
Partner: UNT Libraries

Ozone

Description: Although it represents only a tiny fraction of the atmosphere, ozone is crucial for life on Earth. Depending on where ozone resides, it can protect or harm life on Earth.
Date: 2002
Creator: NASA Earth Observatory
Partner: UNT Libraries

Ozone

Description: The term "ozone depletion" means more than just the natural destruction of ozone, it means that ozone loss is exceeding ozone creation.
Date: 2002
Creator: NASA Earth Observatory
Partner: UNT Libraries

Ozone

Description: The amount and distribution of ozone molecules in the stratosphere varies greatly over the globe. Ozone molecules are transported around the stratosphere much as water clouds are transported in the troposphere. Therefore, scientists observing ozone fluctuations over just one spot could not know whether a change in local ozone levels meant an alteration in global ozone levels, or simply a fluctuation in the concentration over that particular spot. Satellites have given scientists the ability to overcome this problem because they provide a picture of what is happening daily over the entire Earth.
Date: 2002
Creator: NASA Earth Observatory
Partner: UNT Libraries

An Evaluation of the Correlation Between Shale Gas Development and Ozone Pollution within the Barnett Shale Region

Description: Presentation for the 2014 Fracturing Impacts and Technologies Conference. This presentation discusses an evaluation of the correlation between shale gas development and ozone pollution within the Barnett Shale region.
Date: September 4, 2014
Creator: Ahmadi, Mahdi & John, Kuruvilla
Partner: UNT College of Arts and Sciences

Conceptual Framework for the Development of an Air Quality Monitoring Station in Denton, Texas

Description: Denton, Texas consistently reaches ozone nonattainment levels. This has led to a large focus of air pollution monitoring efforts in the region, with long-range transport being explored as a key contributor. For this study, the University of North Texas Discovery Park campus was chosen as a prospective location for an extensive air quality monitoring station. Sixteen years of ozone and meteorological data for five state-run monitoring sites within a 25 mile radius, including the nearest Denton Airport site, was gathered from TCEQ online database for the month of April for the years 2000 to 2015. The data was analyzed to show a historical, regional perspective of ozone near the proposed site. The maximum ozone concentration measured at the Denton Airport location over the 16 year period was measured at 96 ppb in 2001. Experimental ozone and meteorological measurements were collected at the Discovery Park location from March 26 to April 3 and April 8 to April, 2016 and compared to the Denton Airport monitoring site. A time lag in ozone trends and an increase in peak ozone concentrations at the proposed location were observed at the proposed site in comparison to the Denton Airport site. Historical and experimental meteorological data agreed in indicating that southern winds that rarely exceed 20 miles per hour are the predominant wind pattern. Back trajectories, wind roses, pollution roses, and bivariate plots created for peak ozone days during experimental periods support long range transport as a considerable cause of high ozone levels in Denton. Furthermore, a study of the precursor characteristics at the Denton Airport site indicated the site was being affected by a local source of nitrogen dioxide that was not affecting the proposed location. The differences in the Denton Airport site and the proposed site indicate that further monitoring at Discovery Park would ...
Date: August 2016
Creator: Boling, Robyn
Partner: UNT Libraries

Development of Wireless Sensor Network System for Indoor Air Quality Monitoring

Description: This thesis describes development of low cost indoor air quality (IAQ) monitoring system for research. It describes data collection of various parameters concentration present in indoor air and sends data back to host PC for further processing. Thesis gives detailed information about hardware and software implementation of IAQ monitoring system. Also discussed are building wireless ZigBee network, creating user friendly graphical user interface (GUI) and analysis of obtained results in comparison with professional benchmark system to check system reliability. Throughputs obtained are efficient enough to use system as a reliable IAQ monitor.
Date: December 2012
Creator: Borkar, Chirag
Partner: UNT Libraries

Ozone Pollution of Shale Gas Activities in North Texas

Description: The effect of shale gas activities on ground-level ozone pollution in the Dallas-Fort Worth area is studied in detail here. Ozone is a highly reactive species with harmful effects on human and environment. Shale gas development, or fracking, involves activities such as hydraulic fracturing, drilling, fluid mixing, and trucks idling that are sources of nitrogen oxides (NOX) and volatile organic compounds (VOC), two of the most important precursors of ozone. In this study two independent approaches have been applied in evaluating the influences on ozone concentrations. In the first approach, the influence of meteorology were removed from ozone time series through the application of Kolmogorov-Zurbenko low-pass filter, logarithmic transformation, and subsequent multi-linear regression. Ozone measurement data were acquired from Texas Commission on Environmental Quality (TCEQ) monitoring stations for 14 years. The comparison between ozone trends in non-shale gas region and shale gas region shows increasing ozone trends at the monitoring stations in close proximity to the Barnett Shale activities. In the second approach, the CAMx photochemical model was used to assess the sensitivity of ozone to the NOX and VOC sources associated with shale oil and gas activities. Brute force method was applied on Barnett Shale and Haynesville Shale emission sources to generate four hypothetical scenarios. Ozone sensitivity analysis was performed for a future year of 2018 and it was based on the photochemical simulation that TCEQ had developed for demonstrating ozone attainment under the State Implementation Plan (SIP). Results showed various level of ozone impact at different locations within the DFW region attributed to area and point sources of emissions in the shale region. Maximum ozone impact due to shale gas activities is expected to be in the order of several parts per billion, while lower impacts on design values were predicted. The results from the photochemical modeling can ...
Date: May 2016
Creator: Ahmadi, Mahdi
Partner: UNT Libraries

Evaluation of the Influence of Non-Conventional Sources of Emissions on Ambient Air Pollutant Concentrations in North Texas

Description: Emissions of air pollutants from non-conventional sources have been on the rise in the North Texas area over the past decade. These include primary pollutants such as volatile organic compound (VOC) and oxides of nitrogen (NOx) which also act as precursors in the formation of ozone. Most of these have been attributed to a significant increase in oil and gas production activities since 2000 within the Barnett Shale region adjacent to the Dallas-Fort Worth metroplex region. In this study, air quality concentrations measured at the Denton Airport and Dallas Hinton monitoring sites operated by the Texas Commission on Environmental Quality (TCEQ) were evaluated. VOC concentration data from canister-based sampling along with continuous measurement of oxides of nitrogen (NOx), ozone (O3), particulate matter (PM2.5), and meteorological conditions at these two sites spanning from 2000 through 2014 were employed in this study. The Dallas site is located within the urban core of one of the fastest growing cities in the United States, while the Denton site is an exurban site with rural characteristics to it. The Denton Airport site was influenced by natural gas pads surrounding it while there are very few natural gas production facilities within close proximity to the Dallas Hinton site. As of 2013, there were 1362 gas pads within a 10 mile radius to the Denton Airport site but there were only 2 within a 10 mile radius to Dallas Hinton site. The Dallas site displayed higher concentrations of NOx and much lower concentrations of VOC than the Denton site. Extremely high levels of VOC measured at the Denton site corresponded with the increase in oil and gas production activities in close proximity to the monitoring site. Ethane and propane are two major contributors to the measured VOC concentration, suggesting the influence of fugitive emissions of natural gas. ...
Date: August 2015
Creator: Lim, Guo Quan
Partner: UNT Libraries