C. T. McElroy

York University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

K. A. Walker

University of Toronto

P. F. Bernath

Old Dominion University

Kimberly Strong

University of Toronto

J. R. Drummond

Dalhousie University

C. A. McLinden

Environment and Climate Change Canada

J. B. Kerr

Environment and Climate Change Canada

C. D. Boone

University of Waterloo

C. Midwinter

University of Toronto

Christopher E. Sioris

Environment and Climate Change Canada

F. Goutail

Sorbonne Université

Cooperative Institutions

University of Toronto

100

Jet Propulsion Laboratory

University of Colorado Boulder

National Oceanic and Atmospheric Administration

Goddard Space Flight Center

Environment and Climate Change Canada

Langley Research Center

Centre National de la Recherche Scientifique

Cooperative Institute for Research in Environmental Sciences

York University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Intercomparison of atmospheric water vapour measurements in the Canadian high Arctic

Dan Weaver Kimberly Strong Matthias Schneider Penny M. Rowe Christopher E. Sioris

Abstract. Water vapour is a critical component of the Earth system. Techniques to acquire and improve measurements of atmospheric water vapour and its isotopes are under active development. This work presents a detailed intercomparison of water vapour total column measurements taken between 2006 and 2014 at a Canadian high Arctic research site. Instruments include radiosondes, sun photometers, a microwave radiometer, and emission and solar absorption Fourier transform spectrometers (FTSs). Good agreement is observed between all combination of datasets, with correlation coefficients ≥ 0.90 showing high correlations. A variety of biases and calibration issues are revealed and discussed for all instruments. A new FTS dataset, resulting from the MUSICA (Multi-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) retrieval technique, is shown to offer accurate measurements of water vapour total columns; however, measurements show a small wet bias of approximately 6 %. A new dataset derived from Atmospheric Emitted Radiance Interferometer (AERI) measurements is also shown to provide accurate water vapour measurements, which usefully enables measurements to be taken during day and night (especially valuable during Polar Night). In addition, limited profile comparisons are conducted using radiosonde and ground-based FTS measurements. Results show MUSICA FTS profiles were within 15 % of radiosonde measurements throughout the troposphere.

Isotopologue

Microwave radiometer

10.5194/amt-2016-330

Cite

Citations (1)

Supplementary material to "A physically-based correction for stray light in Brewer spectrophotometer data analysis "

Vladimir Savastiouk Henri Diémoz C. T. McElroy

Stray light

10.5194/egusphere-2023-1461-supplement

Cite

Citations (0)

<title>ORACLE (Ozone Research with Advanced Cooperative Lidar Experiment): joint NASA-CSA development of a space-based ozone dial</title>

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1998)

D. Ball Alexander E. Dudelzak Fernand Rheault E. V. Browell Syed Ismail

This paper is presented to give a general description of the ORACLE project and of the technology development results obtained to date. ORACLE is a feasibility study of a fully automated differential absorption lidar for global measurements of tropospheric and stratospheric ozone and aerosols with high vertical and horizontal resolution. The proposed program includes both novel technology demonstrations and obtaining scientific data from spacecraft. These data are needed to address key issues in atmospheric research including the depletion of stratospheric ozone, global warming, atmospheric transport and dynamics, tropospheric ozone budgets, atmospheric chemistry, and the atmospheric impact of hazards. Only a space-based lidar system can provide the required spatial resolution for ozone and aerosols in both the stratosphere and the troposphere on a global scale at all required altitudes. To deliver these data, the most novel technologies such as all-solid-state lasers, photon-counting detectors and ultra-lightweight deployable telescopes must be employed in the mission payload.

Tropospheric ozone

Dial

Payload (computing)

10.1117/12.332422

Cite

Citations (4)

Wintertime measurements of stratospheric HNO3 as part of the ISY polar ozone project

Washington, DC International Astronautical Federation Congress (1992)

H. Fast C. T. McElroy D. I. Wardle

Ozone Depletion

Source

Cite

Citations (0)

Intercomparison of UV-visible measurements of ozone and NO<sub>2</sub> during the Canadian Arctic ACE validation campaigns: 2004–2006

A. Fraser F. Goutail Kimberly Strong P. F. Bernath C. D. Boone

Abstract. The first three Canadian Arctic ACE validation campaigns were held during polar sunrise at Eureka, Nunavut, Canada (80° N, 86° W) from 2004 to 2006 in support of validation of the ACE (Atmospheric Chemistry Experiment) satellite mission. Three or four zenith-sky viewing UV-visible spectrometers have taken part in each of the three campaigns. The differential slant column densities and vertical column densities from these instruments have been compared following the methods of the UV-visible Working Group of the NDACC (Network for Detection of Atmospheric Composition Change). The instruments are found to partially agree within the required accuracies for both species, although both the vertical and slant column densities are more scattered than required. This might be expected given the spatial and temporal variability of the Arctic stratosphere in spring. The vertical column densities are also compared to integrated total columns from ozonesondes and 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) instruments on board ACE. For both species, the columns from the ground-based instruments and the ozonesondes are found to generally agree within their combined error bars. The ACE-FTS ozone partial columns and the ground-based total columns agree within 4.5%, averaged over the three campaigns. The ACE-MAESTRO ozone partial columns are generally smaller than those of the ground-based instruments, by an average of 9.9%, and are smaller than the ACE-FTS columns by an average of 14.4%. The ACE-FTS NO2 partial columns are an average of 13.4% smaller than the total columns from the ground-based instruments, as expected. The ACE-MAESTRO NO2 partial columns are larger than the total columns of the ground-based instruments by an average of 2.5% and larger than the partial columns of the ACE-FTS by an average of 15.5%.

Sunrise

Occultation

Zenith

Atmospheric chemistry

10.5194/acpd-7-16283-2007

Cite

Citations (2)

An evaluation of Odin/OSIRIS limb pointing and stratospheric ozone through comparisons with ozonesondes

Canadian Journal of Physics (2007)

C. A. McLinden Vitali Fioletov C. S. Haley N. D. Lloyd Chris Roth

Five-plus years of Odin/OSIRIS (Optical Spectrograph and Infrared Imager System) ozone profiles (version 3.0 and SaskMART) have been compared with coincident ozonesonde profiles from the tropopause to the middle stratosphere (~10–35 km). The OSIRIS(v3.0)-sonde comparisons, together with the “knee” technique, suggest that OSIRIS pointing is stable with an accuracy (systematic uncertainty) of 100~m and a precision (random uncertainty) of 400 m. Comparison of coincident profiles revealed excellent overall agreement with differences generally not exceeding 10% between 10 and 35 km. During periods of satellite eclipse larger differences above 25 km were found and concluded to be the result of flexing of the spacecraft frame brought about by cooling. Uncertainties derived from the intercomparison suggest an OSIRIS precision of 25–30% at 10 km, reaching a minimum of about 4–6% in the middle-stratosphere (23–28 km), and 6–8% at 35 km. Ozonesonde uncertainties were also derived and found to be slightly larger in the tropics than mid-latitudes, possibly due to a lack of column normalization at some of the tropical stations. OSIRIS SaskMART ozone, an alternative ozone data product, was found to be very comparable with the v3.0 ozone, with slightly smaller biases relative to the ozonesondes. OSIRIS is concluded to be a robust and accurate source of stratospheric ozone profiles. PACS Nos.: 82.33.Tb, 95.75.Qr, 42.68.–w

Osiris

Tropopause

Microwave Limb Sounder

10.1139/p07-112

Cite

Citations (14)

Balloon-borne radiometer measurement of Northern Hemisphere mid-latitude stratospheric HNO₃ profiles spanning 12 years

M. Toohey B. M. Quine K. Strong P. F. Bernath C. D. Boone

Source

Cite

Citations (0)

Altitude distributions of stratospheric constituents from ground‐based measurements at twilight

Journal of Geophysical Research Atmospheres (1991)

Richard McKenzie P. V. Johnston C. T. McElroy J. B. Kerr Susan Solomon

A technique for extracting height profiles from ground‐based column measurements at twilight is introduced. Its sensitivities to chemical processes, initialization, and air mass factors are investigated. The method is applied to observations made at Lauder, New Zealand, in 1987. The technique provides information on the vertical structure of atmospheric absorbers such as ozone or NO 2 from the surface to about 50 km and is particularly valuable for identifying the influence of pollution on such measurements. When tropospheric pollution is low, it yields profiles in reasonable agreement with model predictions and with satellite measurements.

Twilight

Ground level

Initialization

10.1029/91jd01361

Cite

Citations (86)

Modernization of the Canadian Ozone Monitoring Network

Ozone in the Atmosphere (1989)

W. F. J. Evans J. B. Kerr D. I. Wardle C. T. McElroy

Source

Cite

Citations (1)

Measurements of Stratospheric Trace Gases Column Density and J-values Using UV-Visible Photodiode Array Spectroscopy during the MANTRA 2002 Balloon Campaign

Hongjiang Wu Caroline R. Nowlan Kimberly Strong C. T. McElroy C. Midwinter

Three spectrophotometers were used to measure stratospheric constituents during the MANTRA2002 balloon campaign. The instrument, calibration, and observations are described. The raw data are now being analyzed, and the results will be compared with previous balloon flights.

Trace gas

Mantra

Photodiode

10.1364/ors.2003.owb4

Cite

Citations (0)