Ciarán McElroy

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P. F. Bernath, C. T. McElroy, M. C. Abrams, C. D. Boone, M. Butler, C. Camy-Peyret, M. Carleer, C. Clerbaux, P.-F. Coheur, R. Colin, P. DeCola, M. DeMazière, J. R. Drummond, D. Dufour, W. F. J. Evans, H. Fast, D. Fussen, K. Gilbert, D. E. Jennings, E. J. Llewellyn, R. P. Lowe, E. Mahieu, J. C. McConnell, M. McHugh, S. D. McLeod, R. Michaud, C. Midwinter, R.(More)
Spectral measurements of ultraviolet-B radiation made at Toronto since 1989 indicate that the intensity of light at wavelengths near 300 nanometers has increased by 35 percent per year in winter and 7 percent per year in summer. The wavelength dependence of these trends indicates that the increase is caused by the downward trend in total ozone that was(More)
Chemical ozone destruction occurs over both polar regions in local winter-spring. In the Antarctic, essentially complete removal of lower-stratospheric ozone currently results in an ozone hole every year, whereas in the Arctic, ozone loss is highly variable and has until now been much more limited. Here we demonstrate that chemical ozone destruction over(More)
Sparse matrix by vector multiplication (SMV) is a key operation of many scientific and engineering applications. Field programmable gate arrays (FPGAs) have the potential to significantly improve the performance of computationally intensive applications which are dominated by SMV. A shortcoming of most existing FPGA SMV implementations is that they use(More)
The Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument on the SCISAT satellite is a simple, compact spectrophotometer for the measurement of atmospheric extinction, ozone, nitrogen dioxide, and other trace gases in the stratosphere and upper troposphere as part of the Atmospheric Chemistry(More)
ER-2 aircraft observations of OH and HO2 concentrations in the upper troposphere during the NASA/STRAT campaign are interpreted u sing a photochemical model constrained by local observations of O3, H2O, NO, CO, hydrocarbons, albedo and overhead ozone column. We find that the reaction O(D) + H2O is minor compared to acetone photolysis as a primary source of(More)
Googlepsilas PageRank (PR) eigenvector problem is the worldpsilas largest matrix calculation. The algorithm is dominated by Sparse Matrix by Vector Multiplication (SMVM) where the matrix is very sparse, unsymmetrical and unstructured. The computation presents a serious challenge to general-purpose processors (GPP) and the result is a very lengthy(More)
An algorithm has been developed that retrieves water vapour profiles in the upper troposphere and lower stratosphere from optical depth spectra obtained by the Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument onboard the SCISAT satellite as part of the Atmospheric Chemistry Experiment (ACE)(More)
The importance of measurements of the vertical distribution of odd nitrogen in studies of ozone chemistry and climate change has long being recognized. In this paper, we use the optimal estimation method developed by Rodgers (1976, 1990) to retrieve NO2 vertical profiles from slant column observations made with a portable ultraviolet (UV)-visible zenith-sky(More)
This paper presents extensive validation analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: the ACE Fourier Transform Spectrometer (ACE-FTS) and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. 5 The ACE satellite instruments(More)