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Full-Text Articles in Physical Sciences and Mathematics
Impact Of Solar Radiation On Perchlorate Formation In The Atmosphere: Evidence From Ice Core Measurements, Bishnu Kunwar
Impact Of Solar Radiation On Perchlorate Formation In The Atmosphere: Evidence From Ice Core Measurements, Bishnu Kunwar
Electronic Theses and Dissertations
Perchlorate, which derives from both anthropogenic and natural sources in the current environment, poses a substantial health hazard to humans as it competes with iodine uptake in the thyroid gland. Consequently, there has been considerable concern about minimizing human exposure to environmental perchlorate by restricting its release from man-made sources. However, the absence of a clear understanding regarding the respective contributions of man-made and natural sources has hindered widespread regulation efforts. A 300-year (1700–2007) Summit, Greenland ice core record from a previous study showed relatively stable perchlorate concentrations in Greenland snow prior to 1980, with some elevated perchlorate levels associated …
Volcanic Impact On Stratospheric Chlorine Chemistry And Perchlorate Formation: Evidence From Ice Cores, Joshua Andrew Kennedy
Volcanic Impact On Stratospheric Chlorine Chemistry And Perchlorate Formation: Evidence From Ice Cores, Joshua Andrew Kennedy
Electronic Theses and Dissertations
Perchlorate, suspected to be chemically formed in both the troposphere and stratosphere, has been recently measured in Arctic snow and ice cores. These comprise both discontinuous snow and ice cores from the Canadian Arctic and a continuous record of perchlorate was compiled from an analysis of Greenland ice cores. While the background perchlorate concentration typically is very low, a few spikes in concentration coinciding with deposition of volcanic sulfate were observed in the Greenland record, suggesting that perchlorate levels in the atmosphere may be impacted by volcanic eruptions. As of yet, no work has been done to investigate the connection …
Investigating The Atmospheric Production Of Perchlorate: Inference From Polar Ice Cores, Thomas S. Cox
Investigating The Atmospheric Production Of Perchlorate: Inference From Polar Ice Cores, Thomas S. Cox
Electronic Theses and Dissertations
Perchlorate (ClO4) in the environment is of concern, because of potential health risks to humans, among other reasons. Evidence suggests that the majority of environmental perchlorate is formed in the atmosphere (likely in the stratosphere), in chemical processes involving ozone and stratospheric chlorine. A lack of knowledge in regards to the processes has resulted in a limited understanding of the environmental conditions and variables that influence perchlorate production and consequently perchlorate prevalence and variability in the environment. In this study, perchlorate was measured, using an established ion chromatography-‐electrospray ionization-‐tandem mass spectrometry (IC-‐ESI-‐ MS/MS) technique, in over 1,600 snowpit …
Determination Of Volcanic Impact On Perchlorate Using Polar Ice Cores, Alex Georgiev, Collin Livingston, Cody Ward
Determination Of Volcanic Impact On Perchlorate Using Polar Ice Cores, Alex Georgiev, Collin Livingston, Cody Ward
The Journal of Undergraduate Research
Arctic (Greenland) ice core samples covering the time period of 1638-1646 were analyzed for perchlorate and sulfate concentrations. The sulfate data show a signal corresponding to the 1640 eruption of the Komaga-Take volcano in Japan. Perchlorate concentrations show a significant increase at the time of the Komaga-Take eruption. It is concluded that a positive correlation likely exists between stratospheric volcanic eruptions and perchlorate concentration in the environment. When a volcano has enough explosive force to inject substances into the stratosphere, some of the substances, such as sulfate, can remain in the stratosphere for months and spread all over the global …