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144 results on '"Drummond, J.R."'

6. Design of a difference-frequency infrared laser spectrometer for absorption line-shape studies

Author

Wehr, R., Drummond, J.R., and May, A.D.

Subjects
Atmospheric gases -- Optical properties, Optical spectrometers -- Design and construction, Astronomy, Physics
Abstract

An infrared laser spectrometer based on difference-frequency generation in LiI[O.sub.3] is described. The spectrometer has a frequency uncertainty of less than 1 MHz and a signal-to-noise ratio between 3000:1 and 10,000:1. These properties allow the spectrometer to be used for studies of the non-Lorentzian and non-Voigt character of absorption line shapes in atmospheric trace gases. OCIS codes: 300.1030, 300.6190, 300.6320, 300.6340, 300.6360, 300.6390.

Published
2007

10. Dental Health

Author

Drummond, J.R., primary, Chadwick, R.G., additional, Gilbert, A.D., additional, Hanson, C.J., additional, and Scott, B.J.J., additional

Published
2007
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15. Spectroscopic technique for measuring the temperature and pressure cycle of a pressure modulator radiometer

Author

Berman, R., Duggan, P., Le Flohic, M.P., May, A.D., and Drummond, J.R.

Subjects
Radiometers -- Evaluation, Temperature measurements -- Methods, Pressure -- Measurement, Spectrum analysis -- Methods, Astronomy, Physics
Abstract

Precise spectral line measurements of carbon monoxide in an operating pressure modulator cell permit independent determinations of the instantaneous gas temperature and pressure.

Published
1993

16. The Influence of Biomass Burning on the Arctic: Pan-Arctic FTIR Observations and Model Results

Author

Strong, Kimberly, Lutsch, Erik, Conway, S., Drummond, J.R., Hannigan, J.W., Ortega, I., Blumenstock, Thomas, Mahieu, Emmanuel, Makarova, M., Notholt, Justus, Palm, M., Sussmann, R., Kasai, Y., Fisher, J., D.B.A., Jones, Clarisse, Lieven, Clerbaux, Cathy, Coheur, Pierre-François, Dammers, E., Evans, M., Morris, E., Parrington, Mark, Shephard, M.W., Van Damme, Martin, Whitburn, Simon, Department of Physics [Toronto], University of Toronto, Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], National Center for Atmospheric Research [Boulder] (NCAR), Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF), Karlsruher Institut für Technologie (KIT), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, St Petersburg State University (SPbU), Institute of Environmental Physics [Bremen] (IUP), University of Bremen, Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), Centre for Atmospheric Chemistry [Wollongong] (CAC), University of Wollongong [Australia], Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Environment and Climate Change Canada, Wolfson Atmospheric Chemistry Laboratories (WACL), University of York [York, UK], and European Centre for Medium-Range Weather Forecasts (ECMWF)

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

International audience; Transport of biomass burning emissions into the Arctic can cause episodic enhancements of multiple trace gas species. We present a multi-year time series of the total columns of carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C2H6) measured using Fourier Transform Infrared (FTIR) solar absorption spectroscopy at six high-latitude sites: Eureka, Nunavut; Ny Alesund, Norway; Thule, Greenland; Kiruna, Sweden; Poker Flat, Alaska; and St. Petersburg, Russia, and at three mid-latitude sites; Zugspitze, Germany; Jungfraujoch, Switzerland; and Toronto, Ontario. For each site, the inter-annual trends and seasonal variabilities of the CO total column time series are determined and enhancements above ambient levels are used to identify possible wildfire pollution events. Correlations of HCN and C2H6 with CO, back-trajectories from HYSPLIT and FLEXPART, and fire locations from the Moderate Resolution Spectroradiometer (MODIS) confirm the detections and identify the source regions. The GEOS-Chem chemical transport model is run in tagged mode to determine the relative contributions to the observed enhancements from continental-scale biomass burning source regions.Exceptional emissions of CO, HCN, C2H6, and ammonia (NH3) from the 2017 North American wildfires were measured at Eureka and Thule, indicating that wildfires may be a major source of NH3 in the summertime high Arctic. The enhancement ratios of the long- lived species HCN and C2H6 are found to be comparable between sites, but for NH3, the enhancement ratios are strongly dependent on the transport patterns of the smoke plumes. Satellite measurements of NH3 from the Infrared Atmospheric Sounding Instrument (IASI) and Cross-track Infrared Sounder (CrIS) are used to examine the spatial and temporal variabilities of NH3. Comparisons to a high-resolution (0.25° x 0.3125°) nested run of GEOS-Chem using emissions from the Global Fire Assimilation System (GFAS) are performed to evaluate the emission inventories and assess the long-range transport of NH3 to the high Arctic.

Published
2018

23. The polar environment atmospheric research laboratory UV-visible ground-based spectrometer: First measurements of O3, NO2, BrO, and OClO columns

Author

Fraser, A., Adams, C., Drummond, J.R., Goutail, Florence, Manney, G., Strong, K., Department of Physics [Toronto], University of Toronto, 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), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), and New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Arctic, Stratosphere, Ozone, DOAS, Remote sensing, ComputingMilieux_MISCELLANEOUS, UV-visible spectroscopy
Abstract

International audience

Published
2009
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24. 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, G., Blumenstock, T., Boone, C.D., Bramstedt, K., Brogniez, C., Brohede, S., Burrows, J.P., Catoire, V., Dodion, J., Drummond, J.R., Dufour, D.G., Funke, B., Fussen, D., Goutail, F., Griffith, D.W.T., Haley, C.S., Hendrick, F., Höpfner, M., Huret, N., Jones, N., Kar, J., Kramer, I., Llewellyn, E.J., Lopez-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, J.P., Randall, C., Raspollini, P., Ridolfi, M., Richter, A., Schneider, M., Schrems, O., Silicani, M., Stiller, G.P., Taylor, J., Tetard, C., Toohey, M., Vanhellemont, F., Warneke, T., Zawodny, J.M., and Zou, J.

Subjects
Earth sciences, ddc:550
Published
2008

25. Intercomparison of UV-visible measurements of ozone and NO2 during the Canadian Arctic ACE validation campaigns: 2004–2006

Author

Fraser, A., Goutail, Florence, Strong, K., Bernath, P.F., Boone, C., Daffer, W.H., Drummond, J.R., Dufour, D.G., Kerzenmacher, T.E., Manney, G.L., Mcelroy, C.T., Midwinter, C., Mclinden, C.A., Nichitiu, F., Nowlan, C.R., Walker, J., Walker, K.A., Wu, H., Zou, J., EGU, Publication, Department of Physics [Toronto], University of Toronto, 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), Department of Chemistry [Waterloo], University of Waterloo [Waterloo], Department of Chemistry [York, UK], University of York [York, UK], Columbus Technologies and Services Inc., Department of Physics and Atmospheric Science [Halifax], Dalhousie University [Halifax], Picomole Instruments Inc., 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, 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), and Department of Chemistry [University of Toronto]

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; 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 of ozone and NO2 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 are larger than the partial columns of the ACE-FTS by an average of 15.5%.

Published
2007
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26. Relationship between variability of the semidiurnal tide in the Northern Hemisphere mesosphere and quasi-stationary planetary waves throughout the global middle atmosphere

Author

Xu, X., Manson, A.H., Meek, C.E., Chshyolkova, T, Drummond, J.R., Hall, C.M., Jacobi, Ch., Riggin, D., Hibbins, Robert E., Tsutsumi, M., Hocking, W.K., Ward, W.E., Xu, X., Manson, A.H., Meek, C.E., Chshyolkova, T, Drummond, J.R., Hall, C.M., Jacobi, Ch., Riggin, D., Hibbins, Robert E., Tsutsumi, M., Hocking, W.K., and Ward, W.E.

Abstract

To investigate possible couplings between planetary waves and the semidiurnal tide (SDT), this work examines the statistical correlations between the SDT amplitudes observed in the Northern Hemisphere (NH) mesosphere and stationary planetary wave (SPW) with wavenumber S=1 (SPW1) amplitudes throughout the global stratosphere and mesosphere. The latter are derived from the Aura-MLS temperature measurements. During NH summer-fall (July–October), the mesospheric SDT amplitudes observed at Svalbard (78° N) and Eureka (80° N) usually do not show persistent correlations with the SPW1 amplitudes in the opposite hemisphere. Although the SDT amplitudes observed at lower latitudes (~50–70° N), especially at Saskatoon (52° N), are often shown to be highly and positively correlated with the SPW1 amplitudes in high southern latitudes, these correlations cannot be sufficiently explained as evidence for a direct physical link between the Southern Hemisphere (SH) winter-early spring SPW and NH summer-early fall mesospheric SDT. This is because the migrating tide's contribution is usually dominant in the mid-high latitude (~50–70° N) NH mesosphere during the local late summer-early fall (July–September). The numerical correlation is dominated by similar low-frequency variability or trends between the amplitudes of the NH SDT and SH SPW1 during the respective equinoctial transitions. In contradistinction, during NH winter (November–February), the mesospheric SDT amplitudes at northern mid-high latitudes (~50–80° N) are observed to be significantly and positively correlated with the SPW1 amplitudes in the same hemisphere in most cases. Because both the SPW and migrating SDT are large in the NH during the local winter, a non-linear interaction between SPW and migrating SDT probably occurs, thus providing a global non-migrating SDT. This is consistent with observations of SDT in Antarctica that are large in summer than in winter. It is suggested that climatological hemispheric asymmetry

Published
2009

27. Vertical and interhemispheric links in the stratosphere-mesosphere as revealed by the day-to-day variability of Aura-MLS temperature data

Author

Xu, X., Manson, A.H., Meek, C.E., Chshyolkova, T., Drummond, J.R., Hall, C.M., Riggin, D.M., Hibbins, R.E., Xu, X., Manson, A.H., Meek, C.E., Chshyolkova, T., Drummond, J.R., Hall, C.M., Riggin, D.M., and Hibbins, R.E.

Abstract

The coupling processes in the middle atmosphere have been a subject of intense research activity because of their effects on atmospheric circulation, structure, variability, and the distribution of chemical constituents. In this study, the day-to-day variability of Aura-MLS (Microwave Limb Sounder) temperature data are used to reveal the vertical and interhemispheric coupling processes in the stratosphere-mesosphere during four Northern Hemisphere winters (2004/2005–2007/2008). The UKMO (United Kingdom Meteorological Office) assimilated data and mesospheric winds from MF (medium frequency) radars are also applied to help highlight the coupling processes. In this study, a clear vertical link can be seen between the stratosphere and mesosphere during winter months. The coolings and reversals of northward meridional winds in the polar winter mesosphere are often observed in relation to warming events (Sudden Stratospheric Warming, SSW for short) and the associated changes in zonal winds in the polar winter stratosphere. An upper-mesospheric cooling usually precedes the beginning of the warming in the stratosphere by 1–2 days. Inter-hemispheric coupling has been identified initially by a correlation analysis using the year-to-year monthly zonal mean temperature. Then the correlation analyses are performed based upon the daily zonal mean temperature. From the original time sequences, significant positive (negative) correlations are generally found between zonal mean temperatures at the Antarctic summer mesopause and in the Arctic winter stratosphere (mesosphere) during northern mid-winters, although these correlations are dominated by the low frequency variability (i.e. the seasonal trend). Using the short-term oscillations (less than 15 days), the statistical result, by looking for the largest magnitude of correlation within a range of time-lags (0 to 10 days; positive lags mean that the Antarctic summer mesopause is lagging), indicates that the temporal variability of

Published
2009

28. Digital divider circuit for a laser-beam-pointing stabilization system

Author

Sinclair, P.M., Drummond, J.R., and May, A.D.

Subjects
Digital electronics -- Usage, Laser beams -- Research, Astronomy, Physics
Abstract

A digital divider circuit is used in a feedback circuit that is designed to stabilize laser-beam pointing. Key words: Digital divider, beam-pointing stability.

Published
1995

31. Fowler, Wirth see difficulties ahead; keynoter Reuss urges telcos to make capital recovery a priority

Author

Myers, Del and Drummond, J.R.

Subjects
Telephone, Business, Telecommunications industry, United States Independent Telephone Association
Abstract

Fowler assures crowd that deregulation will not proceed without consideration of impact on industry ... Wirth expresses concern for the transitional period ... Reuss sets telco priorities as recovery of capital investments, upgrading and maintenance of plants, competitive pricing, and fair competition with alternate distribution systems.

Published
1981

33. 'Show Me State' is affable host to 1st regional showcase of '82

Author

Drummond, J.R. and Myers, Del

Subjects
Telephone, Telecommunications equipment industry, Business, Telecommunications industry, United States Independent Telephone Association, United States Telecommunications Suppliers Association
Published
1982

48. Line mixing in the Raman Q branch in D[sub 2] and mixtures of D[sub 2] in He and Ar.

Author

Sheldon, G.D., Fakhr-Eslam, S.H., Sinclair, P.M., Drummond, J.R., and May, A.D.

Subjects
RAMAN effect, NOBLE gases, ASYMMETRY (Chemistry)
Abstract

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2001
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49. Broadening and shifting of four rovibrational Raman lines of D[sub 2] at 100.7 K.

Author

Forsman, J.W., Sheldon, G.D., Fakhr-Eslam, S.H., Drummond, J.R., and May, A.D.

Subjects
RAMAN effect, RAMAN spectroscopy, SPECTROMETERS
Abstract

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2001
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50. Lineshifts in the Fundamental Band of CO: Confirmation of Experimental Results for N2and Comparison with Theory

Author

Luo, Caiyan, Berman, R., Predoi-Cross, Adriana, Drummond, J.R., and May, A.D.

Abstract

We have used a three-channel version of a tunable difference frequency laser spectrometer to measure the collisionally induced lineshifts at room temperature for 26 lines of the fundamental band of CO perturbed by nitrogen. Each lineshift was obtained directly by comparing the line center positions of two simultaneous recordings, one for a pressure-shifted line, and the other for the same line in pure CO line at very low pressure. The experimental results are found to be in complete agreement with earlier measurements and confirm that shifts as small as 3 MHz may be measured in such a system. Our results are compared with theoretical calculations. The part of the shifting coefficient antisymmetric with respect to a change in sign of the line number m, is in disagreement with the calculations.

Published
1999
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