Sensitivity Study on Canadian Air Quality Measurements from Geostationary Orbit
Date
2020-01-31
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-7853-1149
Type
Thesis
Degree Level
Masters
Abstract
Tropospheric Emissions: Monitoring of Pollution (TEMPO) is a satellite-based remote sensing air quality instrument destined for geostationary orbit over North America beginning in 2022. TEMPO will take hourly measurements with unprecedented resolution which will greatly benefit air quality forecasting, monitoring of emission sources, and health impact studies related to air quality. The field of regard of TEMPO contains a significant portion of Canada, including regions of particular interest such as major population centers and the Alberta oil sands. However, the standard retrieval algorithms that will be used to process TEMPO data do not explicitly account for some of the challenges that exist for measurements over Canada, such as pervasive snow cover, shallow lines of sight, and limited daylight hours. With the ultimate goal of creating new or optimized algorithms that address these challenges and allow Canada to take full advantage of TEMPO, standard retrieval algorithms for nitrogen dioxide and ozone have been replicated and studied. These algorithms use differential optical absorption spectroscopy (DOAS), the technique that will be used to create the standard TEMPO products, and they will serve as a baseline for comparison with future algorithms. The SASKTRAN radiative transfer framework, developed at the University of Saskatchewan, has been utilized to calculate air mass factors, key quantities in the DOAS-style retrieval, using three complementary methods which are all in agreement with each other. End-to-end retrievals modelled after cutting-edge algorithms used by modern instruments have been implemented, and they have been used to conduct a preliminary sensitivity study that quantifies the major sources of uncertainty in DOAS retrievals using synthetic TEMPO measurements.
Description
Keywords
Remote sensing, Air quality, Differential optical absorption spectroscopy, Nitrogen dioxide
Citation
Degree
Master of Science (M.Sc.)
Department
Physics and Engineering Physics
Program
Physics