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278 results on '"Mcelroy, C. T."'

1. Hydrogen Radicals, Nitrogen Radicals, and the Production of O$_3$ in the Upper Troposphere

Author

Wennberg, P. O., Hanisco, T. F., Jaeglé, L., Jacob, D. J., Hintsa, E. J., Lanzendorf, E. J., Anderson, J. G., Keim, E. R., Donnelly, S. G., Del Negro, L. A., Fahey, D. W., McKeen, S. A., Salawitch, R. J., Webster, C. R., May, R. D., Herman, R. L., Proffitt, M. H., Margitan, J. J., Atlas, E. L., Schauffler, S. M., Flocke, F., McElroy, C. T., and Bui, T. P.

Published
1998

4. Past Changes in the Vertical Distribution of Ozone Part 1: Measurement Techniques, Uncertainties and Availability

Author

Hassler, B, Petropavlovskikh, I, Staehelin, J, August, T, Bhartia, P. K, Clerbaux, C, Degenstein, D, Maziere, M. De, Dinelli, B. M, Dudhia, A, Dufour, G, Frith, S. M, Froidevaux, L, Godin-Beekmann, S, Granville, J, Harris, N. R. P, Hoppel, K, Hubert, D, Kasai, Y, Kurylo, M. J, Kyrola, E, Lambert, J.-C, Levelt, P. F, McElroy, C. T, McPeters, R. D, Munro, R, Nakajima, H, Parrish, A, Raspollini, P, Remsberg, E. E, Rosenlof, K. H, Rozanov, A, Sano, T, Sasano, Y, Shiotani, M, and Zawodny, J. M

Subjects
Earth Resources And Remote Sensing
Abstract

Peak stratospheric chlorofluorocarbon (CFC) and other ozone depleting substance (ODS) concentrations were reached in the mid- to late 1990s. Detection and attribution of the expected recovery of the stratospheric ozone layer in an atmosphere with reduced ODSs as well as efforts to understand the evolution of stratospheric ozone in the presence of increasing greenhouse gases are key current research topics. These require a critical examination of the ozone changes with an accurate knowledge of the spatial (geographical and vertical) and temporal ozone response. For such an examination, it is vital that the quality of the measurements used be as high as possible and measurement uncertainties well quantified. In preparation for the 2014 United Nations Environment Programme (UNEP)/World Meteorological Organization (WMO) Scientific Assessment of Ozone Depletion, the SPARC/IO3C/IGACO-O3/NDACC (SI2N) Initiative was designed to study and document changes in the global ozone profile distribution. This requires assessing long-term ozone profile data sets in regards to measurement stability and uncertainty characteristics. The ultimate goal is to establish suitability for estimating long-term ozone trends to contribute to ozone recovery studies. Some of the data sets have been improved as part of this initiative with updated versions now available. This summary presents an overview of stratospheric ozone profile measurement data sets (ground and satellite based) available for ozone recovery studies. Here we document measurement techniques, spatial and temporal coverage, vertical resolution, native units and measurement uncertainties. In addition, the latest data versions are briefly described (including data version updates as well as detailing multiple retrievals when available for a given satellite instrument). Archive location information for each data set is also given.

Published
2014
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7. The NOx-HNO3 system in the lower stratosphere: Insights from in situ measurements and implications of J(sub HNO3)-[OH] relationship

Author

Perkins, K. K., Koch, L. C., Bonne, G. P., Wennberg, P. O., Salawitch, R. J., McElroy, C. T., Cohen, R. C., Hanisco, T. F., Hinsta, E. J., Voss, P. B., Stimpfle, R. M., Anderson, J. G., Lanzendorf, E. J., Del Negro, L. A., Gao, R. S., Bui, T. P., and Loewenstein, M.

Subjects
Photolysis -- Methods, Stratosphere -- Research, Nitric acid -- Research, Chemicals, plastics and rubber industries
Abstract

The situ observations were used to evaluate the primary mechanisms that control NOx-HNO3 exchange and to understand their control over the partitioning between NO2 and HNO3 in regions of continuous sunlight. The steady-state description of NOx-HNO3 exchange reveals the significant influence of the tight correlation between the photolysis rate of HNO3 and [OH] established in situ measurements throughout the lower stratosphere.

Published
2001

8. Sources, sinks, and the distribution of OH in the lower stratosphere

Author

Hanisco, T. F., Perkins, K. K., Anderson, J. G., Gao, R. S., Margitan, J. J., Wennberg, P. O., Lanzendorf, E. J., Voss, P. B., Stimpfle, R. M., Fahey, D., Cohen, R. C., Salawitch, R. J., Hintsa, E. J., Midwinter, C., and McElroy, C. T.

Subjects
United States. National Aeronautics and Space Administration -- Research, Hydroxylation -- Research, Stratosphere -- Research, Chemicals, plastics and rubber industries
Abstract

The extensive measurement campaigns by the NASA ER-2 research aircraft have obtained a nearly pole-to-pole database of the species that control HOx (OH + HO2) chemistry. The measurements in the lower stratosphere shows a remarkably tight correlation of OH concentration with the solar zenith angle (SZA).

Published
2001

9. Slant Column Measurements of O3 and NO2 During the NDSC Intercomparison of Zenith-Sky UV-Visible Spectrometers in June 1996

Author

Roscoe, H. K., Johnston, P. V., Van Roozendael, M., Richter, A., Sarkissian, A., Roscoe, J., Preston, K. E., Lambert, J-C., Hermans, C., DeCuyper, W., Dzienus, S., Winterrath, T., Burrows, J., Goutail, F., Pommereau, J-P., D'Almeida, E., Hottier, J., Coureul, C., Didier, R., Pundt, I., Bartlett, L. M., McElroy, C. T., Kerr, J. E., Elokhov, A., Giovanelli, G., Ravegnani, F., Premuda, M., Kostadinov, I., Erle, F., Wagner, T., Pfeilsticker, K., Kenntner, M., Marquard, L. C., Gil, M., Puentedura, O., Yela, M., Arlander, D. W., Kastad Hoiskar, B. A., Tellefsen, C. W., Karlsen Tornkvist, K., Heese, B., Jones, R. L., Aliwell, S. R., and Freshwater, R. A.

Published
1999
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17. The Atmospheric Imaging Mission for Northern Regions: AIM-North

Author

Nassar, Ray, primary, McLinden, Chris, additional, Sioris, Christopher E., additional, McElroy, C. T., additional, Mendonca, Joseph, additional, Tamminen, Johanna, additional, MacDonald, Cameron G., additional, Adams, Cristen, additional, Boisvenue, Céline, additional, Bourassa, Adam, additional, Cooney, Ryan, additional, Degenstein, Doug, additional, Drolet, Guillaume, additional, Garand, Louis, additional, Girard, Ralph, additional, Johnson, Markey, additional, Jones, Dylan B.A., additional, Kolonjari, Felicia, additional, Kuwahara, Bruce, additional, Martin, Randall V., additional, Miller, Charles E., additional, O’Neill, Norman, additional, Riihelä, Aku, additional, Roche, Sébastien, additional, Sander, Stanley P., additional, Simpson, William R., additional, Singh, Gurpreet, additional, Strong, Kimberly, additional, Trishchenko, Alexander P., additional, van Mierlo, Helena, additional, Zanjani, Zahra Vaziri, additional, Walker, Kaley A., additional, and Wunch, Debra, additional

Published
2019
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20. Stratospheric Ozone Intercomparison Campaign (STOIC) 1989: Overview

Author

Margitan, J. J, Barnes, R. A, Brothers, G. B, Butler, J, Burris, J, Connor, B. J, Ferrare, R. A, Kerr, J. B, Komhyr, W. D, McCormick, M. P, McDermid, I. S, McElroy, C. T, McGee, T. J, Miller, A. J, Owens, M, Parrish, A. D, Parsons, C. L, Torres, A. L, Tsou, J. J, and Walsh, T. D

Subjects
Geophysics
Abstract

The NASA Upper Atmosphere Research Program organized a Stratospheric Ozone Intercomparison Campaign (STOIC) held in July-August 1989 at the Table Mountain Facility (TMF) of the Jet Propulsion Laboratory (JPL). The primary instruments participating in this campaign were several that had been developed by NASA for the Network for the Detection of Stratospheric Change: the JPL ozone lidar at TMF, the Goddard Space Flight Center trailer-mounted ozone lidar which was moved to TMF for this comparison, and the Millitech/LaRC microwave radiometer. To assess the performance of these new instruments, a validation/intercomparison campaign was undertaken using established techniques: balloon ozonesondes launched by personnel from the Wallops Flight Facility and from NOAA Geophysical Monitoring for Climate Change (GMCC) (now Climate Monitoring and Diagnostics Laboratory), a NOAA GMCC Dobson spectrophotometer, and a Brewer spectrometer from the Atmospheric Environment Service of Canada, both being used for column as well as Umkehr profile retrievals. All of these instruments were located at TMF and measurements were made as close together in time as possible to minimize atmospheric variability as a factor in the comparisons. Daytime rocket measurements of ozone were made by Wallops Flight Facility personnel using ROCOZ-A instruments launched from San Nicholas Island. The entire campaign was conducted as a blind intercomparison, with the investigators not seeing each others data until all data had been submitted to a referee and archived at the end of the 2-week period (July 20 to August 2, 1989). Satellite data were also obtained from the Stratospheric Aerosol and Gas Experiment (SAGE 2) aboard the Earth Radiation Budget Satellite and the Total Ozone Mapping Spectrometer (TOMS) aboard Nimbus 7. An examination of the data has found excellent agreement among the techniques, especially in the 20- to 40-km range. As expected, there was little atmospheric variability during the intercomparison, allowing for detailed statistical comparisons at a high level of precision. This overview paper summarizes the campaign and provides a 'road map' to subsequent papers in this issue by the individual instrument teams which will present more detailed analysis of the data and conclusions.

Published
1995
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21. Improved retrieval of nitrogen dioxide (NO2) column densities by means of MKIV Brewer spectrophotometers

Author

Diémoz, H., Siani, Anna Maria, Redondas, A., Savastiouk, V., Mcelroy, C. T., Navarro Comas, M., and Hase, F.

Subjects
Spectrophotometers, Espectrofotómetros, Dióxido de nitrógeno, Nitrogen dioxide
Abstract

A new algorithm to retrieve nitrogen dioxide (NO2) column densities using MKIV ("Mark IV") Brewer spectrophotometers is described. The method includes several improvements, such as a more recent spectroscopic data set, the reduction of measurement noise, interference by other atmospheric species and instrumental settings, and a better determination of the zenith sky air mass factor. The technique was tested during an ad hoc calibration campaign at the high-altitude site of Izaña (Tenerife, Spain) and the results of the direct sun and zenith sky geometries were compared to those obtained by two reference instruments from the Network for the Detection of Atmospheric Composition Change (NDACC): a Fourier Transform Infrared Radiometer (FTIR) and an advanced visible spectrograph (RASAS-II) based on the differential optical absorption spectrometry (DOAS) technique. To determine the extraterrestrial constant, an easily implementable extension of the standard Langley technique for very clean sites without tropospheric NO2 was developed which takes into account the daytime linear drift of stratospheric nitrogen dioxide due to photochemistry. The measurement uncertainty was thoroughly determined by using a Monte Carlo technique. Poisson noise and wavelength misalignments were found to be the most influential contributors to the overall uncertainty, and possible solutions are proposed for future improvements. The new algorithm is backward-compatible, thus allowing for the reprocessing of historical data sets.

Published
2018

22. Visible light nitrogen dioxide spectrophotometer intercomparison: Mount Kobau, British Columbia, July 28 to August 10, 1991

Author

Mcelroy, C. T, Elokhov, A. S, Elansky, N, Frank, H, Johnston, P, and Kerr, J. B

Subjects
Meteorology And Climatology
Abstract

Under the auspices of the World Meteorological Organization, Environment Canada hosted an international comparison of visible light spectrophotometers at Mt. Kobau, British Columbia in August of 1991. Instruments from four countries were involved. The intercomparison results have indicated that some significant differences exist in the responses of the various instruments, and have provided a basis for the comparison of the historical data sets which currently exist as a result of the independent researches carried out in the past in the former Soviet Union, New Zealand, and Canada.

Published
1994

23. SPEAM-II experiment for the measurement of stratospheric NO2, O3 and aerosols

Author

Mcelroy, C. T, Mcarthur, L. J. B, Kerr, J. B, Wardle, D. I, Tarasick, D, and Midwinter, C

Subjects
Geophysics
Abstract

Following the success of the Sunphotometer Earth Atmosphere Measurement (SPEAM-I) experiment, a more involved experiment was developed to fly as part of the second set of Canadian Experiments (CANEX-2) which will fly on the US Space Shuttle in the fall of 1992. The instrument complement includes an IBM-PC compatible control computer, a hand-held diode array spectrophotometer, and an interference-filter, limb imaging radiometer for the measurement of the atmospheric airglow. The hand-held spectrometer will measure nitrogen dioxide, ozone and aerosols. The limb imaging radiometer will observe emissions from the O2(1 DELTA) and O2(1 SIGMA) airglow bands. Only the spectrophotometer will be discussed here.

Published
1994

24. The determination of HNO3 column amounts from tunable diode laser heterodyne spectrometer spectra taken at Jungfruajoch, Switzerland

Author

Fogal, P. F, Murcray, D. G, Martin, N. A, Swann, N. R, Woods, P. T, and Mcelroy, C. T

Subjects
Meteorology And Climatology
Abstract

In May of 1991 a tunable diode laser heterodyne spectrometer built by the National Physical Laboratory was operated at the International Scientific Station of the Jungfraujoch (46.5 deg N, 8.0 deg E, altitude 3.56 km). Nitric acid spectra in the region of 868 wavenumbers were recorded at sunset and sunrise on two separate days at a resolution of 0.0013 wavenumbers with a signal-to-noise ratio of approximately 130:1. A vertical column amount of HNO3 of 1.61 x 10(exp 16) molecules/sq cm was determined using an atmospheric transmission model developed at the University of Denver. The mean of a number of mid-latitude, northern hemisphere profiles was used as the initial profile for the inversion. A comparison of different initial profiles provides information on the sensitivity of the retrieved column amount of 1.61 x 10(exp 16) molecules/sq cm lies within the range of values published in the World Meteorological Organization Report no. 16 (1986), but is considerably larger than the value of (0.99 - 1.29) x 10(exp 16) reported by Rinsland et al. (1991) for June during the period 1986 to 1990.

Published
1994

25. Ozone trends estimated from Umkehr observations made at Edmonton, Alberta, Canada

Author

Mcelroy, C. T, Hare, E. W, and Kerr, J. B

Subjects
Meteorology And Climatology
Abstract

A Brewer Ozone Spectrophotometer has been in service at the Canadian ozone monitoring station at Stony Plain (53.55 deg N, 114.10 deg W), near Edmonton, Alberta, since 1984. During that time, the instrument has been operated in a fully automated mode that includes the collection of morning and evening Umkehr observations. Some 197 Umkehr observations have been analyzed to make an estimate of the temporal trend in ozone amount at high altitude over the station during the last 8 years. This work has shown that at 40 km the trend in the ozone concentration has been observed to be 0.14 plus or minus 0.10 percent per year.

Published
1994

26. The Canadian Ozone Watch and UV-B advisory programs

Author

Kerr, J. B, Mcelroy, C. T, Tarasick, D. W, and Wardle, D. I

Subjects
Meteorology And Climatology
Abstract

The Ozone Watch, initiated in March, 1992, is a weekly bulletin describing the state of the ozone layer over Canada. The UV-B advisory program, which started in May, 1992, produces daily forecasts of clear-sky UV-B radiation. The forecast procedures use daily ozone measurements from the eight-station monitoring network, the output from the Canadian operational forecast model and a UV-B algorithm based on three years of spectral UV-B measurements with the Brewer spectrophotometer.

Published
1994

27. Stratospheric Ozone Intercomparison Campaign (STOIC) 1989: Overview

Author

Whiteman, D, Walsh, T. D, Tsou, J. J, Torres, A. L, Parson, C. L, Parrish, A. D, Owens, M, Miller, A. J, McGee, T. J, McElroy, C. T, McDermid, I. S, McCormick, M. P, Kohmyr, W. D, Kerr, J. B, Ferrare, R. A, Connor, B. J, Burris, J, Butler, J, Brothers, G. B, Barnes, R. A, and Margitan, J. J

Abstract

The NASA Upper Atmosphere Research Program organized a Stratospheric Ozone Intercomparison Campaign (STOIC) held in July-August 1989 at the Table Mountain Facility (TMF) of the Jet Propulsion Laboratory (JPL).

Published
1994

28. Stratospheric Ozone Intercomparison Campaign (STOIC) 1989: Overview

Author

Margitan, J. J, Barnes, R. A, Brothers, G. B, Butler, J, Burris, J, Connor, B. J, Ferrare, R. A, Kerr, J. B, Kohmyr, W. D, McCormick, M. P, McDermid, I. S, McElroy, C. T, McGee, T. J, Miller, A. J, Owens, M, Parrish, A. D, Parson, C. L, Torres, A. L, Tsou, J. J, Walsh, T. D, and Whiteman, D

Published
1994

29. Heterodyne spectrophotometry of ozone in the 9.6-micron band using a tunable diode laser

Author

Mcelroy, C. T, Goldman, A, Fogal, P. F, and Murcray, D. G

Subjects
Geophysics
Abstract

Tunable diode laser heterodyne spectrophotometry (TDLHS) has been used to make extremely high resolution (0.0003/cm) solar spectra in the 9.6-micron ozone band. Observations have shown that a signal-to-noise ratio of 120:1 (about 30 percent of theoretical) for an integration time of 1/8 s can be achieved at a resolution of 0.0013 wave numbers. The spectral data have been inverted to yield a total column amount of ozone, in good agreement with that measured at the nearby NOAA ozone monitoring facility in Boulder, Colorado. Line positions for several ozone lines in the spectral region 996-997/cm are reported. Recent improvements have produced a signal-to-noise ratio of 95:1 (about 40 percent of theoretical) at 0.0003/cm and extended the range of wavelengths which can be observed.

Published
1990

30. SI2N overview paper: ozone profile measurements: techniques, uncertainties and availability

Author

Hassler B., Petropavlovskikh I., Staehelin J., August T., Bhartia P. K., Clerbaux C., Degenstein D., Mazière M. De, Dinelli B. M., Dudhia A., Dufour G., Frith S. M., Froidevaux L., Godin-Beekmann S., Granville J., Harris N. R. P., Hoppel K., Hubert D., Kasai Y., Kurylo M. J., Kyrölä E., Lambert J. C., Levelt P. F., McElroy C. T., and McPeters R. D.

Published
2014

33. Balloon-borne radiometer measurements of Northern Hemisphere mid-latitude stratospheric HNO3 profiles spanning 12 years

Author

Toohey, M., Quine, B. M., Strong, K., Bernath, P. F., Boone, C. D., Jonsson, A. I., McElroy, C. T., Walker, K. A., and Wunch, D.

Subjects
lcsh:Chemistry, lcsh:QD1-999, Caltech Library Services, lcsh:Physics, lcsh:QC1-999
Abstract

Low-resolution atmospheric thermal emission spectra collected by balloon-borne radiometers over the time span of 1990–2002 are used to retrieve vertical profiles of HNO3, CFC-11 and CFC-12 volume mixing ratios between approximately 10 and 35 km altitude. All of the data analyzed have been collected from launches from a Northern Hemisphere mid-latitude site, during late summer, when stratospheric dynamic variability is at a minimum. The retrieval technique incorporates detailed forward modeling of the instrument and the radiative properties of the atmosphere, and obtains a best fit between modeled and measured spectra through a combination of onion-peeling and optimization steps. The retrieved HNO3 profiles are consistent over the 12-year period, and are consistent with recent measurements by the Atmospheric Chemistry Experiment-Fourier transform spectrometer satellite instrument. We therefore find no evidence of long-term changes in the HNO3 summer mid-latitude profile, although the uncertainty of our measurements precludes a conclusive trend analysis.

Published
2007

34. Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

Author

Fraser, A., Bernath, P. F., Blatherwick, R. D., Drummond, J. R., Fogal, P. F., Fu, D., Goutail, F., Kerzenmacher, T. E., McElroy, C. T., Midwinter, C., Olson, J. R., Strong, K., Walker, K. A., Wunch, D., and Young, I. J.

Subjects
lcsh:Chemistry, lcsh:QD1-999, Caltech Library Services, lcsh:Physics, lcsh:QC1-999
Abstract

The MANTRA (Middle Atmosphere Nitrogen TRend Assessment) 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W) from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs) that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change) standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%). NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%).

Published
2007

35. Tropospheric emissions: Monitoring of pollution (TEMPO)

Author

Zoogman, P., Liu, X., Suleiman, R. M., Pennington, W. F., Flittner, D. E., Al-Saadi, J. A., Hilton, B. B., Nicks, D. K., Newchurch, M. J., Carr, J. L., Janz, S. J., Andraschko, M. R., Arola, A., Baker, B. D., Canova, B. P., Chan Miller, C., Cohen, R. C., Davis, J. E., Dussault, M. E., Edwards, D. P., Fishman, J., Ghulam, A., González Abad, G., Grutter, M., Herman, J. R., Houck, J., Jacob, Daniel J., Joiner, J., Kerridge, B. J., Kim, J., Krotkov, N. A., Lamsal, L., Li, C., Lindfors, A., Martin, R. V., McElroy, C. T., McLinden, C., Natraj, V., Neil, D. O., Nowlan, C. R., O'Sullivan, E. J., Palmer, P.I., Pierce, Robert Bradley, Pippin, M. R., Saiz-Lopez, A., Spurr, R. J. D., Szykman, J. J., Torres, O., Veefkind, J. P., Zoogman, P., Liu, X., Suleiman, R. M., Pennington, W. F., Flittner, D. E., Al-Saadi, J. A., Hilton, B. B., Nicks, D. K., Newchurch, M. J., Carr, J. L., Janz, S. J., Andraschko, M. R., Arola, A., Baker, B. D., Canova, B. P., Chan Miller, C., Cohen, R. C., Davis, J. E., Dussault, M. E., Edwards, D. P., Fishman, J., Ghulam, A., González Abad, G., Grutter, M., Herman, J. R., Houck, J., Jacob, Daniel J., Joiner, J., Kerridge, B. J., Kim, J., Krotkov, N. A., Lamsal, L., Li, C., Lindfors, A., Martin, R. V., McElroy, C. T., McLinden, C., Natraj, V., Neil, D. O., Nowlan, C. R., O'Sullivan, E. J., Palmer, P.I., Pierce, Robert Bradley, Pippin, M. R., Saiz-Lopez, A., Spurr, R. J. D., Szykman, J. J., Torres, O., and Veefkind, J. P.

Abstract

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O), nitrogen dioxide (NO), sulfur dioxide (SO), formaldehyde (HCO), glyoxal (CHO), bromine monoxide (BrO), IO (iodine monoxide), water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O chemistry cycle. Multi-spectral observations provide sensitivity to O in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the

Published
2017

36. Correcting Stray Light in Single-monochromator Brewer Spectrophotometers

Author

Karppinen, Tomi, Redondas, Alberto, García Cabrera, Rosa Delia, Lakkala, Kaisa, McElroy, C. T., and Kyrö, Esko

Subjects
Ozone measurements, Brewer spectrophotometers, Stray light
Abstract

Póster presentado en: Quadrennial Ozone Symposium 2012 (QOS 2012), celebrado del 27 al 31 de agosto de 2012 en Toronto, Canada.

Published
2012

37. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

Author

Adams, C., Strong, K., Batchelor, R. L., Bernath, P. F., Brohede, S., Boone, C., Degenstein, D., Daffer, W. H., Drummond, J. R., Fogal, P. F., Farahani, E., Fayt, C., Fraser, A., Goutail, Florence, Hendrick, F., Kolonjari, F., Lindenmaier, R., Manney, G., Mcelroy, C. T., Mclinden, C. A., Mendonca, J., Park, J.-H., Pavlovic, B., Pazmino, Andrea, Roth, C., Savastiouk, V., Walker, K. A., Weaver, D., Zhao, X., Department of Physics [Toronto], University of Toronto, NCAR Earth Systems Laboratory (NESL), National Center for Atmospheric Research [Boulder] (NCAR), Department of Chemistry [York, UK], University of York [York, UK], Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Department of Chemistry and Biochemistry [Norfolk], Old Dominion University [Norfolk] (ODU), Department of Earth and Space Sciences [Göteborg], Chalmers University of Technology [Göteborg], University of Saskatchewan [Saskatoon] (U of S), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), School of Geosciences [Edinburgh], University of Edinburgh, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT), Air Quality Research Division [Toronto], Environment and Climate Change Canada, York University [Toronto], Full Spectrum Science Inc. [Toronto], National Aeronautics and Space Administration (NASA), Belgian PRODEX SECPEA and A3C projects, European Commission, European Project: GEOMON, European Project: 284421,EC:FP7:SPA,FP7-SPACE-2011-1,NORS(2011), and California Institute of Technology (CALTECH)-NASA

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], lcsh:TA715-787, lcsh:Earthwork. Foundations, lcsh:TA170-171, lcsh:Environmental engineering
Abstract

The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC). The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS) instruments, one Bruker Fourier transform infrared spectrometer (FTIR) and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC) guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14-52 km ozone and 17-40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2) plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% for ozone and -0.2 ± 0.1% for v2.2 minus v3.3 NO2. Ozone columns were constructed from 14-52 km satellite and 0-14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree with the ground-based ozone total columns with mean relative differences of 0.1-7.3%. For NO2, partial columns from 17 km upward were scaled to noon using a photochemical model. Mean relative differences between OSIRIS, ACE-FTS and ground-based NO2 measurements do not exceed 20%. ACE-MAESTRO measures more NO2 than the other instruments, with mean relative differences of 25-52%. Seasonal variation in the differences between partial columns is observed, suggesting that there are systematic errors in the measurements, the photochemical model corrections, and/or in the coincidence criteria. For ozone spring-time measurements, additional coincidence criteria based on stratospheric temperature and the location of the polar vortex were found to improve agreement between some of the instruments. For ACE-FTS v2.2 minus Bruker FTIR, the 2007-2009 spring-time mean relative difference improved from -5.0 ± 0.4% to -3.1 ± 0.8% with the dynamical selection criteria. This was the largest improvement, likely because both instruments measure direct sunlight and therefore have well-characterized lines-of-sight compared with scattered sunlight measurements. For NO2, the addition of a ±1° latitude coincidence criterion improved spring-time intercomparison results, likely due to the sharp latitudinal gradient of NO2 during polar sunrise. The differences between satellite and ground-based measurements do not show any obvious trends over the missions, indicating that both the ACE and OSIRIS instruments continue to perform well.

Published
2012
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38. Intercomparison of ground-based and satellite NO2measurements above eureka, Nunavut

Author

Adams, C., Strong, K., Lindenmaier, Rodica, Batchelor, R., Park, J.-H., Weaver, D., Fraser, A., Mendonca, J., Drummond, J. R., Goutail, Florence, Pazmino, Andrea, Walker, K. A., Bernath, P., Boone, C., Mcelroy, C. T., Degenstein, D., Mclinden, C. A., Manney, G., Daffer, W., Adams, Christopher, Department of Physics [Toronto], University of Toronto, National Center for Atmospheric Research [Boulder] (NCAR), Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry [York, UK], University of York [York, UK], Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Air Quality Research Division [Toronto], Environment and Climate Change Canada, University of Saskatchewan [Saskatoon] (U of S), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Facultad de Quimica [Santiago], Pontificia Universidad Católica de Chile (UC), and Cardon, Catherine

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Published
2010

41. Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records

Author

Hubert, D., primary, Lambert, J.-C., additional, Verhoelst, T., additional, Granville, J., additional, Keppens, A., additional, Baray, J.-L., additional, Cortesi, U., additional, Degenstein, D. A., additional, Froidevaux, L., additional, Godin-Beekmann, S., additional, Hoppel, K. W., additional, Kyrölä, E., additional, Leblanc, T., additional, Lichtenberg, G., additional, McElroy, C. T., additional, Murtagh, D., additional, Nakane, H., additional, Russell III, J. M., additional, Salvador, J., additional, Smit, H. G. J., additional, Stebel, K., additional, Steinbrecht, W., additional, Strawbridge, K. B., additional, Stübi, R., additional, Swart, D. P. J., additional, Taha, G., additional, Thompson, A. M., additional, Urban, J., additional, van Gijsel, J. A. E., additional, von der Gathen, P., additional, Walker, K. A., additional, Wolfram, E., additional, and Zawodny, J. M., additional

Published
2015
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42. Validation of water vapour profiles from the Atmospheric Chemistry Experiment (ACE)

Author

Carleer, M. R., Boone, C. D., Walker, K. A., Bernath, P. F., Strong, K., Sica, R. J., Randall, C. E., Vömel, H., Kar, J., Höpfner, M., Milz, M., Von Clarmann, T., Kivi, R., Valverde-Canossa, J., Sioris, C. E., Izawa, M. R. M., Dupuy, E., Mcelroy, C. T., Drummond, J. R., Nowlan, C. R., Zou, J., Nichitiu, F., Lossow, S., Urban, Jakub, Murtagh, D., Dufour, D. G., Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Department of Physics [Toronto], University of Toronto, Department of Chemistry, Department of Physics and Astronomy [London, ON], University of Western Ontario (UWO), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Forschungszentrum Karlsruhe and Universität Karlsruhe, Finnish Meteorological Institute (FMI), Universidad Nacional, UNIVERSIDAD NACIONAL, Environment and Climate Change Canada, Department of Earth Sciences [London, ON], Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], Department of Meteorology [Stockholm] (MISU), Stockholm University, Department of Radio and Space Science [Göteborg], Chalmers University of Technology [Göteborg], Picomole Instruments Inc., and EGU, Publication

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; The Atmospheric Chemistry Experiment (ACE) mission was launched in August 2003 to sound the atmosphere by solar occultation. Water vapour (H2O), one of the most important molecules for climate and atmospheric chemistry, is one of the key species provided by the two principal instruments, the infrared Fourier Transform Spectrometer (ACE-FTS) and the MAESTRO UV-Visible spectrometer (ACE-MAESTRO). The first instrument performs measurements on several lines in the 1362?2137 cm?1 range, from which vertically resolved H2O concentration profiles are retrieved, from 7 to 90 km altitude. ACE-MAESTRO measures profiles using the water absorption band in the near infrared part of the spectrum at 926.0?969.7 nm. This paper presents a comprehensive validation of the ACE-FTS profiles. We have compared the H2O volume mixing ratio profiles with space-borne (SAGE II, HALOE, POAM III, MIPAS, SMR) observations and measurements from balloon-borne frostpoint hygrometers and a ground based lidar. We show that the ACE-FTS measurements provide H2O profiles with small retrieval uncertainties in the stratosphere (better than 5% from 15 to 70 km, gradually increasing above). The situation is unclear in the upper troposphere, due mainly to the high variability of the water vapour volume mixing ratio in this region. A new water vapour data product from the ACE-MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) is also presented and initial comparisons with ACE-FTS are discussed.

Published
2008

43. Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE)

Author

Kerzenmacher, T., Wolff, M. A., Strong, K., Dupuy, E., Walker, K. A., Amekudzi, L. K., Batchelor, R. L., Bernath, P. F., Berthet, Gwenaël, Blumenstock, T., Boone, C. D., Bramstedt, K., Brogniez, C., Brohede, S., Burrows, J. P., Catoire, Valéry, Dodion, J., Drummond, J. R., Dufour, D. G., Funke, B., Fussen, D., Goutail, Florence, Griffith, D. W. T., Haley, C. S., Hendrick, F., Höpfner, M., Huret, Nathalie, Jones, N., Kar, J., Kramer, I., Llewellyn, E. J., López-Puertas, M., Manney, G., Mcelroy, C. T., Mclinden, C. A., Melo, S., Mikuteit, S., Murtagh, D., Nichitiu, F., Notholt, J., Nowlan, C., Piccolo, C., Pommereau, Jean-Pierre, Randall, C., Raspollini, P., Ridolfi, M., Richter, A., Schneider, M., Schrems, O., Silicani, M., Stiller, G. P., Taylor, James, Tétard, C., Toohey, M., Vanhellemont, F., Warneke, T., Zawodny, J. M., Zou, J., Department of Physics [Toronto], University of Toronto, Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Institut für Umweltphysik [Bremen] (IUP), Universität Bremen, Department of Chemistry [York, UK], University of York [York, UK], Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Radio and Space Science [Göteborg], Chalmers University of Technology [Göteborg], Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], Picomole Instruments Inc., Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Chemistry [Wollongong], University of Wollongong [Australia], Centre for Research in Earth and Space Science [Toronto] (CRESS), York University [Toronto], Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT), Environment and Climate Change Canada, Canadian Space Agency (CSA), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Atmospheric and Oceanic Sciences [Boulder] (ATOC), Istituto di Fisica Applicata 'Nello Carrara' (IFAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Dipartimento di Chimica Fisica e Inorganica [Bologna], Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), NASA Langley Research Center [Hampton] (LaRC), Institut für Umweltphysik [Bremen] ( IUP ), Laboratoire de physique et chimie de l'environnement ( LPCE ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Institut für Meteorologie und Klimaforschung ( IMK ), Karlsruher Institut für Technologie ( KIT ), Laboratoire d’Optique Atmosphérique - UMR 8518 ( LOA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Service d'aéronomie ( SA ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), University of Wollongong, Centre for Research in Earth and Space Science [Toronto] ( CRESS ), Institute of Space and Atmospheric Studies [Saskatoon] ( ISAS ), University of Saskatchewan [Saskatoon] ( U of S ), Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), New Mexico Institute of Mining and Technology [New Mexico Tech] ( NMT ), Canadian Space Agency ( CSA ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], Laboratory for Atmospheric and Space Physics [Boulder] ( LASP ), University of Colorado Boulder [Boulder], Department of Atmospheric and Oceanic Sciences [Boulder] ( ATOC ), Istituto di Fisica Applicata 'Nello Carrara' ( IFAC ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Università di Bologna [Bologna] ( UNIBO ), Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research ( AWI ), NASA Langley Research Center [Hampton] ( LaRC ), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Meteorologie und Klimaforschung (IMK), Karlsruher Institut für Technologie (KIT), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), California Institute of Technology (CALTECH)-NASA, Consiglio Nazionale delle Ricerche [Roma] (CNR), and Università di Bologna [Bologna] (UNIBO)

Subjects
lcsh:Chemistry, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:QD1-999, lcsh:Physics, lcsh:QC1-999
Abstract

Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE), using an infrared Fourier Transform Spectrometer (ACE-FTS) and (for NO2) an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation). In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY), stellar occultation measurements (GOMOS), limb measurements (MIPAS, OSIRIS), nadir measurements (SCIAMACHY), balloon-borne measurements (SPIRALE, SAOZ) and ground-based measurements (UV-VIS, FTIR). Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR) profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS) and SAGE II (for ACE-FTS (sunrise) and MAESTRO) and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average) agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.

Published
2008

44. Validation of GOMOS-Envisat vertical profiles of O3, NO2, NO3, and aerosol extinction using balloon-borne instruments and analysis of the retrievals

Author

Bernath, P. F., Mcelroy, C. T., Abrams, M. C., Boone, C. D., Butler, M., Camy-Peyret, C., Carleer, M., Clerbaux, Cathy, Coheur, P.-F., Colin, R., De Cola, P., De Mazière, M., Drummond, J. R., Dufour, D., Evans, W. F. J., Fast, H., Fussen, D., Gilbert, K., Jennings, D. E., Llewellyn, E. J., Lowe, R. P., Mahieu, E., Mcconnell, J. C., Mchugh, M., Mcleod, S. D., Michaud, R., Midwinter, C., Nassar, R., Nichitiu, F., Nowlan, C., Rinsland, C. P., Rochon, Y. J., Rowlands, N., Semeniuk, K., Simon, P., Skelton, R., Sloan, J. J., Soucy, M.-A., Strong, K., Tremblay, P., Turnbull, D., Walker, K. A., Walkty, I., Wardle, D. A., Wehrle, V., Zander, R., Zou, J., Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Meteorological Service of Canada, Environment and Climate Change Canada, FastMetrix Inc., Laboratoire de Physique moléculaire et applications (LPMA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA Headquarters, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Department of Physics [Toronto], University of Toronto, Department of Physics and Astronomy [Peterborough], Trent University, Department of Physics and Astronomy [London, ON], University of Western Ontario (UWO), NASA Goddard Space Flight Center (GSFC), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Department of Earth and Space Science and Engineering [York University - Toronto] (ESSE), York University [Toronto], GATS Inc., Canadian Space Agency (CSA), NASA Langley Research Center [Hampton] (LaRC), EMS Technologies Canada Ltd., ABB Bomem Inc., Département de génie électrique et de génie informatique (GEL-GIF), Université Laval [Québec] (ULaval), Bristol Aerospace Ltd., and the European Space Agency (ESA), the French Space Agency (CNES) and the German Space Agency (DLR)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU]Sciences of the Universe [physics], stratosphere, Validation, balloon
Abstract

The UV-visible Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument onboard Envisat performs nighttime measurements of ozone, NO2, NO3 and of the aerosol extinction, using the stellar occultation method. We have conducted a validation exercise using various balloon-borne instruments in different geophysical conditions from 2002 to 2006, using GOMOS measurements performed with stars of different magnitudes. GOMOS and balloon-borne vertical columns in the middle stratosphere are in excellent agreement for ozone and NO2. Some discrepancies can appear between GOMOS and balloon-borne vertical profiles for the altitude and the amplitude of the concentration maximum. These discrepancies are randomly distributed, and no bias is detected. The accuracy of individual profiles in the middle stratosphere is 10 % for ozone and 25 % for NO2. On the other hand, the GOMOS NO3 retrieval is difficult and no direct validation can be conducted. The GOMOS aerosol content is also well estimated, but the wavelength dependence can be better estimated if the aerosol retrieval is performed only in the visible domain. We can conclude that the GOMOS operational retrieval algorithm works well and that GOMOS has fully respected its primary objective for the study of the trends of species in the middle stratosphere, using the profiles in a statistical manner. Some individual profiles can be partly inaccurate, in particular in the lower stratosphere. Improvements could be obtained by reprocessing some GOMOS transmissions in case of specific studies in the middle and lower stratosphere when using the individual profiles.

Published
2008
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45. Vertical profiles of lightning-produced NO2 enhancements in the upper troposphere observed by OSIRIS

Author

Sioris, C. E., Mclinden, C. A., Martin, R. V., Sauvage, B., Haley, C. S., Lloyd, N. D., Llewellyn, E. J., Bernath, P. F., Boone, C. D., Brohede, S., Mcelroy, C. T., EGU, Publication, Atomic and Molecular Physics Division [Cambridge] (AMP), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution-Harvard University [Cambridge]-Smithsonian Institution, Institute of Space and Atmospheric Studies [Saskatoon] (ISAS), Department of Physics and Engineering Physics [Saskatoon], University of Saskatchewan [Saskatoon] (U of S)-University of Saskatchewan [Saskatoon] (U of S), Experimental Studies Section, Environment and Climate Change Canada, Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], Department of Chemistry [York, UK], University of York [York, UK], Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Department of Radio and Space Science [Göteborg], Chalmers University of Technology [Göteborg], Experimental Studies Sect., Centre for Research in Earth and Space Science [Toronto] (CRESS), and York University [Toronto]

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; The purpose of this study is to perform a global search of the upper troposphere (z?10 km) for enhancements of nitrogen dioxide and determine their sources. This is the first application of satellite-based limb scattering to study upper tropospheric NO2. We have searched two years (May 2003?May 2005) of OSIRIS (Optical Spectrograph and Infrared Imager System) operational NO2 concentrations (version 2.3/2.4) to find large enhancements in the observations by comparing with photochemical box model calculations and by identifying local maxima in NO2 volume mixing ratio. We find that lightning is the main production mechanism responsible for the large enhancements in OSIRIS NO2 observations as expected. Similar patterns in the abundances and spatial distribution of the NO2 enhancements are obtained by perturbing the lightning within the GEOS-Chem 3-dimensional chemical transport model. In most cases, the presence of lightning is confirmed with coincident imagery from LIS (Lightning Imaging Sensor) and the spatial extent of the NO2 enhancement is mapped using nadir observations of tropospheric NO2 at high spatial resolution from SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) and OMI (Ozone Monitoring Instrument). The combination of the lightning and chemical sensors allows us to investigate globally the role of lightning to the abundance of NO2 in the upper troposphere (UT). Lightning contributes 60% of the tropical upper tropospheric NO2 in GEOS-Chem simulations. The spatial and temporal distribution of NO2 enhancements from lightning (May 2003?May 2005) is investigated. The enhancements generally occur at 12 to 13 km more frequently than at 10 to 11 km. This is consistent with the notion that most of the NO2 is forming and persisting near the cloud top altitude in the tropical upper troposphere. The latitudinal distribution is mostly as expected. In general, the thunderstorms exhibiting weaker vertical development (e.g. 11?z?13 km) extend latitudinally as far poleward as 45° but the thunderstorms with stronger vertical development (z?14 km) tend to be located within 33° of the equator. There is also the expected hemispheric asymmetry in the frequency of the NO2 enhancements, as most were observed in the northern hemisphere for the period analyzed.

Published
2007

46. Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model

Author

Melo, S. M. L., Blatherwick, R., Davies, J., Fogal, P., Grandpré, J., Mcconnell, J., Mcelroy, C. T., Mclandress, C., Murcray, F. J., Olson, J. R., Semeniuk, K., Shepherd, T. G., Strong, K., David Tarasick, Williams-Rioux, B. J., EGU, Publication, Canadian Space Agency (CSA), Department of Physics [Toronto], University of Toronto, Department of Physics and Astronomy [Hanover], Dartmouth College [Hanover], Environment and Climate Change Canada, Department of Earth and Space Science and Engineering [York University - Toronto] (ESSE), York University [Toronto], Department of Atmospheric and Oceanic Sciences [Montréal], and McGill University = Université McGill [Montréal, Canada]

Subjects
lcsh:Chemistry, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:QD1-999, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:Physics, lcsh:QC1-999
Abstract

International audience; In this paper we report on a study conducted using the Middle Atmospheric Nitrogen TRend Assessment (MANTRA) balloon measurements of stratospheric constituents and temperature and the Canadian Middle Atmosphere Model (CMAM). Three different kinds of data are used to assess the inter-consistency of the combined dataset: single profiles of long-lived species from MANTRA 1998, sparse climatologies from the ozonesonde measurements during the four MANTRA campaigns and from HALOE satellite measurements, and the CMAM climatology. In doing so, we evaluate the ability of the model to reproduce the measured fields and to thereby test our ability to describe mid-latitude summertime stratospheric processes. The MANTRA campaigns were conducted at Vanscoy, Saskatchewan, Canada (52° N, 107° W) in late August and early September of 1998, 2000, 2002 and 2004. During late summer at mid-latitudes, the stratosphere is close to photochemical control, providing an ideal scenario for the study reported here. From this analysis we find that: (1) reducing the value for the vertical diffusion coefficient in CMAM to a more physically reasonable value results in the model better reproducing the measured profiles of long-lived species; (2) the existence of compact correlations among the constituents, as expected from independent measurements in the literature and from models, confirms the self-consistency of the MANTRA measurements; and (3) the 1998 measurements show structures in the chemical species profiles that can be associated with transport, adding to the growing evidence that the summertime stratosphere can be much more disturbed than anticipated. The mechanisms responsible for such disturbances need to be understood in order to assess the representativeness of the measurements and to isolate long-term trends.

Published
2007

48. Record Arctic ozone loss in spring 2011 compared with Antarctic ozone hole conditions

Author

Rex, Markus, Wohltmann, Ingo, Lehmann, Ralph, Deckelmann, Holger, von der Gathen, Peter, Balis, D., De Backer, H., Davis, J., Dorokhov, V., Eriksen, P., Gerding, M., Gernandt, Hartwig, Godin-Beekmann, S., Hardadottic, J., Jepsen, N., Johnson, B., Kivi, R., Kyrö, E., Larsen, N., Livesey, N. J., Makshtas, A., Manney, G. L., McElroy, C. T., Moore, D., Nakajima, H., Parrondo, M., Santee, M. L., Skrivankova, P., Stübi, R., Tarasick, D. W., Varghese, S., Varotsos, C., Vömel, H., Walker, K. A., Yushkov, V., Zerefos, C., Zinoviev, Nikita S., Rex, Markus, Wohltmann, Ingo, Lehmann, Ralph, Deckelmann, Holger, von der Gathen, Peter, Balis, D., De Backer, H., Davis, J., Dorokhov, V., Eriksen, P., Gerding, M., Gernandt, Hartwig, Godin-Beekmann, S., Hardadottic, J., Jepsen, N., Johnson, B., Kivi, R., Kyrö, E., Larsen, N., Livesey, N. J., Makshtas, A., Manney, G. L., McElroy, C. T., Moore, D., Nakajima, H., Parrondo, M., Santee, M. L., Skrivankova, P., Stübi, R., Tarasick, D. W., Varghese, S., Varotsos, C., Vömel, H., Walker, K. A., Yushkov, V., Zerefos, C., and Zinoviev, Nikita S.

Abstract

The Arctic winter 2010/2011 was characterized by an unusually stable and cold polar vortex in the lower stratosphere. Meteorological data shows that conditions for the formation of polar stratospheric clouds, and hence the activation of chlorine from reservoir species through heterogeneous processes, were widespread. Values of Vpsc, a temperature based parameter that characterizes the winter average extent of such conditions were in the range of the extreme values reached in the coldest winters on record, i.e., 2000 and 2005. However, in contrast to these previous winters, when the ozone loss period was ended by major stratospheric warmings in March, in 2011 the very stable polar vortex stayed intact and cold well into April. The combination of extremely cold conditions throughout the winter with a long lived and stable vortex in spring led to record chemical destruction of ozone in the Arctic. Based on the measurements of the Match ozonesonde network and the Microwave Limb Sounder (MLS) instrument on Aura we will discuss the degree and the time evolution of this record loss and compare the Arctic ozone loss in 2011 with the range of ozone losses that occurred in early and recent Antarctic ozone holes.

Published
2012

49. Validation of ozone measurements from the Atmospheric Chemistry Experiment (ACE)

Author

Burrows, J. P., Christensen, T., Dupuy, E., Walker, K. A., Kar, J., Boone, C. D., McElroy, C. T., Bernath, P. F., Drummond, J. R., Skelton, R., McLeod, S. D., Hughes, R. C., Nowlan, C. R., Dufour, D. G., Zou, J., Nichitiu, F., Strong, K., Baron, P., Bevilacqua, R. M., Blumenstock, T., Bodeker, G. E., Borsdorff, T., Bourassa, A. E., Bovensmann, H., Boyd, I. S., Bracher, Astrid, Brogniez, C., Catoire, V., Ceccherini, S., Chabrillat, S., Coffey, M. T., Cortesi, U., Davies, J., De Clercq, C., Degenstein, D. A., De Maziere, M., Demoulin, P., Dodion, J., Firanski, B., Fischer, Hubertus, Forbes, G., Froidevaux, L., Fussen, D., Gerard, P., Godin-Beekmann, S., Goutail, F., Granville, J., Griffith, D., Haley, C. S., Hannigan, J. W., Höpfner, M., Jin, J. J., Jones, A., Jones, N. B., Jucks, K., Kagawa, A., Kasai, Y., Kerzenmacher, T. E., Kleinböhl, A., Klekociuk, A. R., Kramer, I., Küllmann, H., Kuttippurath, J., Kyrölä, E., Lambert, J. C., Livesey, N. J., Llewellyn, E. J., Lloyd, N. D., Mahieu, E., Manney, G. L., Marshall, B. T., McConnell, J. C., McCormick, M. P., McDermid, I. S., McHugh, M., McLinden, C. A., Mellqvist, J., Mizutani, K., Murayama, Y., Murtagh, D. P., Oelhaf, H., Parrish, A., Petelina, S. V., Piccolo, C., Pommereau, J.-P., Randall, C. E., Robert, C., Roth, C., Russell III, J. M., Schneider, M., Senten, C., Steck, T., Strandberg, A., Strawbridge, K. B., Sussmann, R., Swart, D. P. J., Tarasick, D. W., Taylor, James, Tétard, C., Thomason, L. W., Thompson, A. M., Tully, M. B., Urban, J., Vanhellemont, F., von Clarmann, T., von der Gathen, Peter, von Savigny, C., Waters, J. W., Witte, J. C., Wolff, Martha Maria, Zawodny, J. M., Burrows, J. P., Christensen, T., Dupuy, E., Walker, K. A., Kar, J., Boone, C. D., McElroy, C. T., Bernath, P. F., Drummond, J. R., Skelton, R., McLeod, S. D., Hughes, R. C., Nowlan, C. R., Dufour, D. G., Zou, J., Nichitiu, F., Strong, K., Baron, P., Bevilacqua, R. M., Blumenstock, T., Bodeker, G. E., Borsdorff, T., Bourassa, A. E., Bovensmann, H., Boyd, I. S., Bracher, Astrid, Brogniez, C., Catoire, V., Ceccherini, S., Chabrillat, S., Coffey, M. T., Cortesi, U., Davies, J., De Clercq, C., Degenstein, D. A., De Maziere, M., Demoulin, P., Dodion, J., Firanski, B., Fischer, Hubertus, Forbes, G., Froidevaux, L., Fussen, D., Gerard, P., Godin-Beekmann, S., Goutail, F., Granville, J., Griffith, D., Haley, C. S., Hannigan, J. W., Höpfner, M., Jin, J. J., Jones, A., Jones, N. B., Jucks, K., Kagawa, A., Kasai, Y., Kerzenmacher, T. E., Kleinböhl, A., Klekociuk, A. R., Kramer, I., Küllmann, H., Kuttippurath, J., Kyrölä, E., Lambert, J. C., Livesey, N. J., Llewellyn, E. J., Lloyd, N. D., Mahieu, E., Manney, G. L., Marshall, B. T., McConnell, J. C., McCormick, M. P., McDermid, I. S., McHugh, M., McLinden, C. A., Mellqvist, J., Mizutani, K., Murayama, Y., Murtagh, D. P., Oelhaf, H., Parrish, A., Petelina, S. V., Piccolo, C., Pommereau, J.-P., Randall, C. E., Robert, C., Roth, C., Russell III, J. M., Schneider, M., Senten, C., Steck, T., Strandberg, A., Strawbridge, K. B., Sussmann, R., Swart, D. P. J., Tarasick, D. W., Taylor, James, Tétard, C., Thomason, L. W., Thompson, A. M., Tully, M. B., Urban, J., Vanhellemont, F., von Clarmann, T., von der Gathen, Peter, von Savigny, C., Waters, J. W., Witte, J. C., Wolff, Martha Maria, and Zawodny, J. M.

Abstract

This paper presents extensive {bias determination} 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. Here we compare the latest ozone data products from ACE-FTS and ACE-MAESTRO with coincident observations from nearly 20 satellite-borne, airborne, balloon-borne and ground-based instruments, by analysing volume mixing ratio profiles and partial column densities. The ACE-FTS version 2.2 Ozone Update product reports more ozone than most correlative measurements from the upper troposphere to the lower mesosphere. At altitude levels from 16 to 44 km, the average values of the mean relative differences are nearly all within +1 to +8%. At higher altitudes (4560 km), the ACE-FTS ozone amounts are significantly larger than those of the comparison instruments, with mean relative differences of up to +40% (about +20% on average). For the ACE-MAESTRO version 1.2 ozone data product, mean relative differences are within ±10% (average values within ±6%) between 18 and 40 km for both the sunrise and sunset measurements. At higher altitudes (~3555 km), systematic biases of opposite sign are found between the ACE-MAESTRO sunrise and sunset observations. While ozone amounts derived from the ACE-MAESTRO sunrise occultation data are often smaller than the coincident observations (with mean relative differences down to −10%), the sunset occultation profiles for ACE-MAESTRO show results that are qualitatively similar to ACE-FTS, indicating a large positive bias (mean relative differences within +10 to +30%) in the 4555 km altitude range. In contrast, there is no significant systematic difference in bias found for the ACE-FTS sunrise and sunset measurements.

Published
2009

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