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1. Temperatures in the upper mesosphere and lower thermosphere from OSIRIS observations of [O.sub.2] A-band emission spectra

Author

Sheese, P.E., Llewellyn, E.J., Gattinger, R.L., Bourassa, A.E., Degenstein, D.A., Lloyd, N.D., and McDade, I.C.

Subjects
Spectra (Spectroscopy) -- Research, Mesosphere -- Observations -- Research, Atmospheric temperature -- Research, Physics
Abstract

Temperatures in the mesosphere--lower thermosphere region (MLT) have been derived from the Optical Spectrograph and InfraRed Imaging System (OSIRIS) observations of [O.sub.2] A-band ([b.sup.1][∑.sup.+.sub.g]-[X.sup.3] [∑.sup.-.sub.g])O-O emission spectra. The observed OSIRIS spectra are inverted pixel by pixel, producing inverted volume emission rate spectra at altitudes between 90 and 110 km, which are compared to modelled temperature dependent [O.sub.2] A-band spectra. The estimated accuracy of the retrieved temperatures is approximately ± 2 K near 90 km and up to ± 6 K at higher altitudes. The developed temperature retrieval technique is presented, and some initial retrieval results are briefly discussed. Nous obtenons les temperatures dans la mesosphere-region de basse thermosphere (la basse atmosphere) a partir des observations, par le spectrographe optique et le systeme d'imagerie infrarouge (OSIRIS), des spectres d'emission ([b.sup.1][[suma].sup.+.sub.g][X.sup.3][[suma].sup.-.sub.g])O-O de la bande A de [O.sub.2]. Les spectres observeis par OSIRIS sont inverses pixel par pixel, produisant des spectres de taux d'emission en volume inverse; a des altitudes entre 90 et 110 km, qui sont alors compare;sa des spectres modelises dependant en temperature de la bande A de [O.sub.2]. Les precisions estimeees des temperatures obtenues est approximativement ±2 K pres de 90 km, jusqu'a ±6 K aux altitudes plus elevees. Nous presentons la technique pour obtenir les temperatures et nous discutons quelques resultats preliminaires. [Traduit par la Redaction], 1. Introduction A detailed understanding of the physics and chemistry of the mesosphere--lower thermosphere (MLT) region of the Earth's atmosphere requires an accurate knowledge of the temperature profile in the [...]

Published
2010
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2. Observation of the 557.7 nm to 297.2 nm brightness ratio in the auroral spectrum with OSIRIS on Odin

Author

Gattinger, R.L., Lloyd, N.D., Bourassa, A.E., Degenstein, D.A., McDade, I.C., and Llewellyn, E.J.

Subjects
Infrared imaging -- Usage -- Analysis, Radiation, Spectrum analysis -- Usage, Physics, Usage, Analysis
Abstract

The two optically forbidden lines of atomic oxygen, O(¹S-¹D) at 557.7 nm and O([1.sup.S] - ³P) at 297.2 nm, serve as important diagnostics in atmospheric, planetary, and cometary studies. Originating from the same upper state, the emission brightness ratio, B(557.7)B(297.2), must necessarily be constant. The reported emission ratio of these two lines from both theoretical and experimental investigations varies by approximately a factor of two. These two emissions are observed simultaneously in aurora] spectra by the OSIRIS spectrograph on the Odin spacecraft, offering another opportunity to perform the ratio measurement. Because of the considerable wavelength separation between these two atomic lines, precise instrumental relative response calibrations can be problematic. To maintain accurate on-orbit spectral calibrations, an atmospheric radiation model with multiple Rayleigh scatter is employed to constantly track instrumental response. An example of a calibrated single bright aurora] spectrum over the full OSIRIS wavelength range of 275 to 815 nm, limb tangent altitude 105 km, is presented. Using a number of individual auroral spectra, the observed 01557.7 nm brightness is plotted versus the observed 01297.2 nm brightness to both verify the required linear relationship and to experimentally determine the brightness ratio. Spectral contamination by other auroral emission features is removed. From the linear fit, the observed B(557.7)B(297.2) ratio is 9.3 ± 0.5. By comparison, a ratio of 9.8 ± 1 was recently reported, determined by combining results from a number of observational databases separated in time and in wavelength coverage. PACS Nos: 32.30-r, 32.70.Fw, 92.60.hc, 92.60.hw Les deux lignes optiques de l'atome d'oxygene, O(¹S - ¹D) a 557,7 nm et O(¹S - ³P) a 297,2 nm sont d'importants outils de diagnostique dans les etudes sur l'atmosphere, les planetes et les cometes. Provenant du meme etat superieur, le rapport d'emission B(557,7) / B(297,2) doit necessairement etre constant. Il y a un facteur de pres de deux entre les valeurs experimentale et theorique du rapport d'emission de ces deux lignes. Elles sont obseevves simultanement par le spectrographe OSIRIS a bord du satellite Odin, ce qui offre une autre possibilite de mesurer ce rapport. A cause de la grande difference en longueur d'onde entre ces deux lignes atomiques, une calibration instrumentale precise sera problematique. Dans le but de maintenir une calibration precise en orbite, nous utilisons un modele de radiation atmospherique avec diffusion Rayleigh multiple, afm de faire un suivi constant de la reponse instrumentale. Nous presentons un exemple d'un spectre auroral calibre sur l'ensemble du domaine spectral d'OSIRIS, de 275 nm a 815 nm, pris dans le limbe tangent a 105 km d'altitude. Utilisant un certain nombre de spectres d'aurore individuels, nous comparons les graphes d'observation de la brillance d'OI 557,5 et de OI 297,2, pour verifier la linearite et determiner experimental ement le rapport de brillance. Nous eliminons la contamination spectrale provenant d'autres emission aurorales. A partir d'un ajustement numerique lineaire, nous avons determine la valeur du rapport B(557,7) / B(297,2) = 9,3 ± 0,5. Pour fin de comparaison, on a recemment rapporte un rapport de 9,8 ± 1, obtenu en combinant des bases de donnees experimentales separees dans le temps et portant sur diverses longueurs d'onde. [Traduit par la Redaction], 1. Introduction The ratio between the O(¹S-¹D) and O(¹S - ³P) transitions has been the subject of numerous investigations. Some of the early theoretical calculations were conducted by Condon [1] [...]

Published
2009
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3. The retrieval of vertical profiles of the ozone number density using Chappuis band absorption information and a multiplicative algebraic reconstruction technique (1)

Author

Roth, C.Z., Degenstein, D.A., Bourassa, A.E., and Llewellyn, E.J.

Subjects
Atmospheric ozone -- Properties -- Models -- Usage, Absorption -- Models -- Usage, Algorithms -- Usage -- Models, Physics, Algorithm, Usage, Models, Properties
Abstract

Abstract: A new algorithm, SaskMART, is presented that uses observations of limb-scattered sunlight and a radiative transfer model to determine the ozone number-density profile up to 35 km altitude. In [...]

Published
2007

4. The impact of sea-glint upon limb radiance (1)

Author

Degenstein, D.A., Bourassa, A.E., Llewellyn, E.J., and Lloyd, N.D.

Subjects
Arabian Sea -- Models, Spectrograph -- Usage -- Equipment and supplies -- Models -- 2002 AD, Radiative transfer -- Models -- Equipment and supplies -- 2002 AD, Ocean -- Properties -- Models -- Equipment and supplies -- 2002 AD, Artificial satellites, European -- Equipment and supplies -- Models -- 2002 AD, Meteorological satellites -- Equipment and supplies -- Usage -- Models -- 2002 AD, Physics, Usage, Models, Properties, Equipment and supplies
Abstract

Abstract: A simple radiative transfer model is developed to calculate the contribution of sea-glint to limb radiance. It is shown that the absolute sea-glint signal peaks between 70. and 80. [...]

Published
2007

6. Effect of volcanic aerosol on stratospheric NO2 and N2O5 from 2002-2014 as measured by Odin-OSIRIS and Envisat-MIPAS

Author

Adams, C., Bourassa, A.E., McLinden, C.A., Sioris, C.E., Von Clarmann, T., Funke, Bernd, Rieger, L.A., Degenstein, D.A., Natural Sciences and Engineering Research Council of Canada, Canadian Space Agency, Swedish National Space Board, Centre National D'Etudes Spatiales (France), Finnish Funding Agency for Innovation, and Ministerio de Economía, Industria y Competitividad (España)

Abstract

Following the large volcanic eruptions of Pinatubo in 1991 and El Chichón in 1982, decreases in stratospheric NO2 associated with enhanced aerosol were observed. The Optical Spectrograph and Infrared Imaging Spectrometer (OSIRIS) measured the widespread enhancements of stratospheric aerosol following seven volcanic eruptions between 2002 and 2014, although the magnitudes of these eruptions were all much smaller than the Pinatubo and El Chichón eruptions. In order to isolate and quantify the relationship between volcanic aerosol and NO2, NO2 anomalies were calculated using measurements from OSIRIS and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). In the tropics, variability due to the quasi-biennial oscillation was subtracted from the time series. OSIRIS profile measurements indicate that the strongest anticorrelations between NO2 and volcanic aerosol extinction were for the 5km layer starting ∼ 3km above the climatological mean tropopause at the given latitude. OSIRIS stratospheric NO2 partial columns in this layer were found to be smaller than background NO2 levels during these aerosol enhancements by up to ∼ 60% with typical Pearson correlation coefficients of R ∼ -0. 7. MIPAS also observed decreases in NO2 partial columns during periods affected by volcanic aerosol, with percent differences of up to ∼ 25% relative to background levels. An even stronger anticorrelation was observed between OSIRIS aerosol optical depth and MIPAS N2O5 partial columns, with R ∼ -0. 9, although no link with MIPAS HNO3 was observed. The variation in OSIRIS NO2 with increasing aerosol was found to be consistent with simulations from a photochemical box model within the estimated model uncertainty.© Author(s) 2017. ., This work was supported by the Natural Sciences and Engineering Research Council (Canada) and the Canadian Space Agency. Odin is a Swedish-led satellite project funded jointly by Sweden (SNSB), Canada (CSA), France (CNES), and Finland (Tekes). Bernd Funke was supported by the Spanish MINECO under grant ESP2014-54362-P.

Published
2017

7. Effect of volcanic aerosol on stratospheric NO2 and N2O5 from 2002-2014 as measured by Odin-OSIRIS and Envisat-MIPAS

Author

Natural Sciences and Engineering Research Council of Canada, Canadian Space Agency, Swedish National Space Board, Centre National D'Etudes Spatiales (France), Finnish Funding Agency for Innovation, Ministerio de Economía, Industria y Competitividad (España), Adams, C., Bourassa, A.E., McLinden, C.A., Sioris, C.E., Von Clarmann, T., Funke, Bernd, Rieger, L.A., Degenstein, D.A., Natural Sciences and Engineering Research Council of Canada, Canadian Space Agency, Swedish National Space Board, Centre National D'Etudes Spatiales (France), Finnish Funding Agency for Innovation, Ministerio de Economía, Industria y Competitividad (España), Adams, C., Bourassa, A.E., McLinden, C.A., Sioris, C.E., Von Clarmann, T., Funke, Bernd, Rieger, L.A., and Degenstein, D.A.

Abstract

Following the large volcanic eruptions of Pinatubo in 1991 and El Chichón in 1982, decreases in stratospheric NO2 associated with enhanced aerosol were observed. The Optical Spectrograph and Infrared Imaging Spectrometer (OSIRIS) measured the widespread enhancements of stratospheric aerosol following seven volcanic eruptions between 2002 and 2014, although the magnitudes of these eruptions were all much smaller than the Pinatubo and El Chichón eruptions. In order to isolate and quantify the relationship between volcanic aerosol and NO2, NO2 anomalies were calculated using measurements from OSIRIS and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). In the tropics, variability due to the quasi-biennial oscillation was subtracted from the time series. OSIRIS profile measurements indicate that the strongest anticorrelations between NO2 and volcanic aerosol extinction were for the 5km layer starting ∼ 3km above the climatological mean tropopause at the given latitude. OSIRIS stratospheric NO2 partial columns in this layer were found to be smaller than background NO2 levels during these aerosol enhancements by up to ∼ 60% with typical Pearson correlation coefficients of R ∼ -0. 7. MIPAS also observed decreases in NO2 partial columns during periods affected by volcanic aerosol, with percent differences of up to ∼ 25% relative to background levels. An even stronger anticorrelation was observed between OSIRIS aerosol optical depth and MIPAS N2O5 partial columns, with R ∼ -0. 9, although no link with MIPAS HNO3 was observed. The variation in OSIRIS NO2 with increasing aerosol was found to be consistent with simulations from a photochemical box model within the estimated model uncertainty.© Author(s) 2017. .

Published
2017

8. Validation of ACE-FTS version 3.5 NOy species profiles using correlative satellite measurements

Author

National Aeronautics and Space Administration (US), Swedish National Space Board, Centre National D'Etudes Spatiales (France), European Space Agency, Canadian Space Agency, German Centre for Air and Space Travel, University of Bremen, Sheese, P.E., Walker, K.A., Boone, C.D., McLinden, C.A., Bernath, P.E., Bourassa, A.E., Burrows, J.P., Degenstein, D.A., Funke, Bernd, Fussen, D., Manney, G.L., Thomas McElroy, C., Murtagh, D., Randall, C.E., Raspollini, P., Rozanov, A., Russell, J.M., Suzuki, M., Shiotani, M., Urban, J., Von Clarmann, T., Zawodny, J.M., National Aeronautics and Space Administration (US), Swedish National Space Board, Centre National D'Etudes Spatiales (France), European Space Agency, Canadian Space Agency, German Centre for Air and Space Travel, University of Bremen, Sheese, P.E., Walker, K.A., Boone, C.D., McLinden, C.A., Bernath, P.E., Bourassa, A.E., Burrows, J.P., Degenstein, D.A., Funke, Bernd, Fussen, D., Manney, G.L., Thomas McElroy, C., Murtagh, D., Randall, C.E., Raspollini, P., Rozanov, A., Russell, J.M., Suzuki, M., Shiotani, M., Urban, J., Von Clarmann, T., and Zawodny, J.M.

Abstract

The ACE-FTS (Atmospheric Chemistry Experiment-Fourier Transform Spectrometer) instrument on the Canadian SCISAT satellite, which has been in operation for over 12 years, has the capability of deriving stratospheric profiles of many of the NO (N+NO+NO+NO+2×NO+HNO+HNO+ClONO+BrONO) species. Version 2.2 of ACE-FTS NO, NO, HNO, NO, and ClONO has previously been validated, and this study compares the most recent version (v3.5) of these five ACE-FTS products to spatially and temporally coincident measurements from other satellite instruments-GOMOS, HALOE, MAESTRO, MIPAS, MLS, OSIRIS, POAM III, SAGE III, SCIAMACHY, SMILES, and SMR. For each ACE-FTS measurement, a photochemical box model was used to simulate the diurnal variations of the NOy species and the ACE-FTS measurements were scaled to the local times of the coincident measurements. The comparisons for all five species show good agreement with correlative satellite measurements. For NO in the altitude range of 25-50 km, ACE-FTS typically agrees with correlative data to within .10 %. Instrumentaveraged mean relative differences are approximately.10% at 30-40 km for NO, within-7% at 8-30 km for HNO, better than.7% at 21-34 km for local morning NO, and better than.8% at 21-34 km for ClONO. Where possible, the variations in the mean differences due to changes in the comparison local time and latitude are also discussed.©2016 Author(s).

Published
2016

9. The OSIRIS instrument on the Odin spacecraft.

Author

Llewellyn, E.J., Lloyd, N.D., Degenstein, D.A., Gattinger, R.L., Petelina, S.V., Bourassa, A.E., Wiensz, J.T., Ivanov, E.V., McDade, I.C., Solheim, B.H., McConnell, J.C., Haley, C.S., von Savigny, C., Sioris, C.E., McLinden, C.A., Griffioen, E., Kaminski, J., Evans, W.F.J., Puckrin, E., and Strong, K.

Subjects
OSIRIS (Electronic computer system), SPECTROGRAPHS, IMAGING systems, SPACE vehicle electronics, SPACE vehicle control systems, TOMOGRAPHY
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
2004
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10. Validation of ozone measurements from the atmospheric chemistry experiment (ACE)

Author

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, A., Brogniez, C., Burrows, J.P., Catoire, V., Ceccherini, S., Chabrillat, S., Christensen, T., Coffey, M.T., Cortesi, U., Davies, J., De Clercq, C., Degenstein, D.A., De Maziere, M., Demoulin, P., Dodion, J., Firanski, B., Fischer, H., Forbes, G., Froidevaux, L., Fussen, D., Gerard, P., Godin-Beekman, 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., Schneider, M., Senten, C., Steck, T., Strandberg, A., Strawbridge, K.B., Sussmann, R., Swart, D.P.J., Tarasick, D.W., Taylor, J.R., Tetard, C., Thomason, L.W., Thompson, A.M., Tully, M.B., Urban, J., Vanhellemont, F., Vigouroux, C., Clarmann, T.Von, Von Der Gathen, P., Savigny, C., Waters, J.W., Witte, J.C., Wolff, M., and Zawodny, J.M.

Subjects
13. Climate action
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 (45–60 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 (~35–55 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 45–55 km altitude range. In contrast, there is no significant systematic difference in bias found for the ACE-FTS sunrise and sunset measurements.

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