Primary Research Areas
Observing CO from Space Using the IASI Instrument
Carbon monoxide (CO) in the troposphere acts as a marker of large-scale influences of pollution on both the regional and global scale, as well as acting as a reference source for incomplete combustion processes. Through its reactions with the hydroxyl radical OH, the concentration of CO is also related to the oxidising capacity of the troposphere, hence providing a chemical marker for the 'local' chemical environment and its state. Investigations into perturbations of the sources, sinks and net surface fluxes of CO are therefore of
increasing importance. In addition to this CO is an ideal tracer for the long range transport of pollution, as the average lifetime of CO is neither too short to result in low concentrations nor too long to lead to a well-mixed tropospheric gas.
Whilst ground-based and in situ instruments are able to measure tropospheric concentrations of CO they are not able to provide global coverage. Observations from space allow for fully
global measurements of CO concentrations to be made over a reasonably short time period.
The Infrared Atmospheric Sounding Interferometer (IASI) is a high-resolution Michelson
interferometer which was launched in 2007 onboard the European polar Meteorological Operational Platform (METEOP-1) satellite. The IASI instrument has a swath of about 2200 km ensuring 99% global coverage twice a day, and is the first of a series of three instruments launched every five years, ensuring a continuity of data for a planned period of 15 years. The IASI instrument thus offers the possibility of high-spectral resolution infrared monitoring of
CO over a very long time period.
Earth observational satellites make measurements of the radiance spectra of the Earth. In order to obtain the atmospheric profiles of pressures, temperatures and the other composing factors of the atmosphere, retrievals must be performed using these radiometric measurements. In essence, the radiation measured by the satellites is an intricate function of all of the components that make up the atmosphere, as well as of the properties of the Earth's surface; retrieval theory ascertains which of these constituents have changed, and by how much, in order to reproduce the signal that has been observed.
My research is concerned with developing a retrieval algorithm which is able to ascertain the concentrations of CO in the troposphere to as accurate degree as possible, and the development of the University of Leicester IASI Retrieval Scheme (ULIRS) forms the fulcrum of my work within the EOS group.
Fires are well known to be a source of CO, and models require good emission estimates to reasonably represent regional and global CO concentrations. Recent satellite data sets for burnt area offer the opportunity to trace more closely the emissions of CO and relationships to fire activity. In particular, in the African continent bottom-up estimates of burnt areas are difficult to evaluate because of a lack of national data available for these countries. The characteristics of burning activity (size of fire, intensity of fire, number of fires, gas emissions) in agricultural and forest areas can be shown to differ greatly, and as such there are also large uncertainties associated with using active fires as a proxy for burnt area. I aim to investigate the short time-scale evolution of both the burnt area and fire products, in a selected area in Africa, and demonstrate any correlation between these measurements and that of the ULIRS retrieved CO product.
Selected Publications and Presentations
S. M. Illingworth, J.J. Remedios, and R. J. Parker, Intercomparison of integrated IASI and AATSR calibrated radiances at 11 and 12 μm, Atmospheric Chemistry and Physics , 9, 6677-6683 , 2009.
Conference Oral Presentations
Samuel Illingworth, Hartmut Bösch, John Remedios, Dave Moore, and Harjinder Sembhi, Tropospheric CO observations Using IASI, NCEO AC Theme Meeting, Edinburgh, UK, November 2009.
Samuel Illingworth, Hartmut Bösch, John Remedios, Dave Moore, and Harjinder Sembhi, Tropospheric CO observations Using IASI, EUMETSAT Conference, Bath, UK, September 2009.
Samuel Illingworth, Hartmut Bösch, John Remedios, Dave Moore, and Harjinder Sembhi, A New OEM Retrieval for IASI CO, NCEO AC Theme Meeting, Oxford, May 2009.
Samuel Illingworth, Hartmut Bösch, John Remedios, Dave Moore, Harjinder Sembhi, and Robert Parker, Tropospheric CO Observations Using IASI datasets and an Optimal Estimation
Retrieval Method, RMetSoc Student Conference, Manchester, UK, September 2008.
Conference Poster Presentations
John Remedios, Karen Veal, John Remedios, Gary Corlett, and David Llewellyn-Jones, Long-Term Satellite Monitoring of (Essential) Climate Variables with the ATSR and IASI Instruments, NCEO General Conference, Oxford, August 2009.
Samuel Illingworth, John Remedios, Hartmut Bösch, Dave Moore, Harjinder Sembhi, and Robert Parker, Tropospheric Observations Using IASI Datasets and an Optimal Estimation Retrieval Method, European Geosciences Union, Vienna, Austria, April 2009.
Samuel Illingworth, John Remedios, Dave Moore, Harjinder Sembhi, and Robert Parker, Tropospheric Observations Using IASI Datasets and an Optimal Estimation Retrieval Method, IGAC Conference, Annecy, France, September 2008. - Specially commended for scientific excellence.
Samuel Illingworth, John Remedios, Dave Moore, Harjinder Sembhi, and Robert Parker, The Importance of Carbon Monoxide in the Atmosphere, Postgraduate Festival, Leicester, UK, June 2008. - Winner of Master Prize for Best Presentation.