Year

2001

Degree Name

Doctor of Philosophy

Department

Department of Chemistry

Abstract

The importance of ozone in the chemistry and the radiative balance of the atmosphere is well established. Several ground and satellite based methods are available for measuring total column or the vertical distribution of ozone. The most common ground based instruments that measure ozone are the Dobson and the Brewer instruments, while ozone sondes measure vertical distribution of ozone. There are six Dobson instruments located in Australia, and ozone sondes are launched from one location (Laverton, Victoria). Solar atmospheric spectroscopy is an established technique to measure the total column amounts of trace atmospheric gases and aerosols. Ozone has a rich spectrum extending from the far ultraviolet to the microwave region. At Wollongong University a high resolution Fourier transform infrared spectrometer (HR-FTIR), a diode array ultraviolet spectrometer and a diode array visible spectrometer have been coupled to the same solar tracker to ensure all three instruments are viewing the same atmospheric column. One aim of this thesis is to develop a rugged, reliable inexpensive solar ultraviolet and visible spectrometer system, suitable to determine total column atmospheric ozone, based on the diode array spectrometer. The shape of the absorption features of the infrared spectrum is influenced by the temperature and pressure environment of the absorbing molecule, and therefore potentially contains information on the vertical distribution of the absorbing molecule. In contrast, in the ultraviolet and visible regions of the spectrum, the environment of the absorbing molecules has limited influence on the shape of the absorption features, and there is greater potential for retrieving accurate total column atmospheric ozone. The thesis also aims to develop the techniques required to determine total column atmospheric ozone from ground based solar high resolution FTIR, and to assess if the complementary information available from solar infrared, ultraviolet and visible spectra can be used to determine some vertical information on atmospheric ozone. The analysis algorithm requires some prior knowledge of the pressure-temperature and ozone vertical profile. Monthly averaged profiles, compiled from data collected remote from the measurement site (Laverton, 1000km south, and Mascot airport, 80km north) are used.

Share

COinS