A ground-based, zenith-sky, UV-visible triple grating spectrometer was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic during polar springtime from 2004 to 2007 as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaigns. From the solar spectra,
ozone, NO2, and BrO vertical column densities (VCDs) have been retrieved using the DOAS (Differential Optical Absorption Spectroscopy) technique. This spectrometer, the UT-GBS (University of Toronto Ground-Based Spectrometer), was also deployed as part of the fourth Middle Atmosphere Nitrogen TRend Assessment (MANTRA) campaign in Vanscoy, Saskatchewan in August and September 2004.
A near-identical spectrometer, the PEARL-GBS, was permanently installed at PEARL
in August 2006 as part of the refurbishment of the laboratory by CANDAC (Canadian
Network for the Detection of Atmospheric Change). Since then, the instrument has been
making continuous measurements, with the exception of during polar night. Vertical
columns of ozone and NO2 can be retrieved year-round. During the 2007 sunrise campaign,
differential slant column densities (DSCDs) of OClO and VCDs of BrO were also
retrieved.
Ozone and NO2 DSCDs and VCDs from the UT-GBS were compared to the DSCDs and VCDs from three other UV-visible, ground-based, grating spectrometers that also participated in the MANTRA and Eureka campaigns. Two methods developed by the UV-visible Working Group of the NDACC (Network for the Detection of Atmospheric Composition Change) were followed. During MANTRA, the instruments were found to partially meet the NDACC standards. The comparisons from Eureka were an improvement on the MANTRA comparisons, and also partially met the NDACC standards. In 2007, the columns from the UT-GBS and PEARL-GBS were compared, and were found to agree within the NDACC standards for both species.
Ozone and NO2 VCDs from the ground-based instruments were also compared to
integrated partial columns from the ACE-FTS (ACE-Fourier Transform Spectrometer)
and ACE-MAESTRO (ACE-Measurements of Aerosol Extinction in the Stratosphere
and Troposphere Retrieved by Occultation) on board the ACE satellite. ACE-FTS partial
columns were found to agree with the ground-based total columns, while the ACE-MAESTRO
partial columns were found to be smaller than expected for ozone and larger than expected for NO2.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/17301 |
| Date | 26 February 2009 |
| Creators | Fraser, Annemarie |
| Contributors | Strong, Kimberly |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 16004551 bytes, application/pdf |
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