Search Results - "Sprague, A.L."

Mercury's exosphere origins and relations to its magnetosphere and surface by Leblanc, F., Chassefière, E., Johnson, R.E., Hunten, D.M., Kallio, E., Delcourt, D.C., Killen, R.M., Luhmann, J.G., Potter, A.E., Jambon, A., Cremonese, G., Mendillo, M., Yan, N., Sprague, A.L.

“…Mariner 10, the only spacecraft that ever passed close to Mercury, revealed several unexpected characteristics: an intrinsic magnetosphere, the highest mean…”
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Distribution and Abundance of Sodium in Mercury's Atmosphere, 1985–1988 by Sprague, A.L., Kozlowski, R.W.H., Hunten, D.M., Schneider, N.M., Domingue, D.L., Wells, W.K., Schmitt, W., Fink, U.

“…We report spectroscopic measurements of sodium in Mercury's atmosphere for the period July 1985–May 1988. Na abundance varies from <1 × 1010atoms cm−2in…”
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Origin and character of the lunar and mercurian atmospheres by Hunten, D.M, Sprague, A.L

“…This article presents a description of the lunar and mercurian atmospheres and the outstanding, unanswered questions. In that spirit we will not repeat the…”
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Observations of Sodium in the Lunar Atmosphere during International Lunar Atmosphere Week, 1995 by Sprague, A.L., Hunten, D.M., Kozlowski, R.W.H., Grosse, F.A., Hill, R.E., Morris, R.L.

“…We report results of a part of an organized effort of five observing groups to simultaneously observe sodium in the lunar atmosphere. International Lunar…”
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Spectral emissivity measurements of Mercury's surface indicate Mg- and Ca-rich mineralogy, K-spar, Na-rich plagioclase, rutile, with possible perovskite, and garnet by Sprague, A.L., Donaldson Hanna, K.L., Kozlowski, R.W.H., Helbert, J., Maturilli, A., Warell, J.B., Hora, J.L.

“…Mid-infrared 2-D spectroscopic measurements from 8.0 to 12.7 μm of Mercury were taken using Boston University's Mid-Infrared Spectrometer and Imager (MIRSI)…”
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Interannual similarity and variation in seasonal circulation of Mars' atmospheric Ar as seen by the Gamma Ray Spectrometer on Mars Odyssey by Sprague, Ann L., Boynton, William V., Forget, Francois, Lian, Yuan, Richardson, Mark, Starr, Richard, Metzger, Albert E., Hamara, David, Economou, Thanasis

“…More than 3 Mars' years (MY) of atmospheric argon (Ar) measurements are used to study annual and seasonal variations in atmospheric transport and mixing. Data…”
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The 0.7–5.3 μm IR spectra of Mercury and the Moon: Evidence for high-Ca clinopyroxene on Mercury by Warell, J., Sprague, A.L., Emery, J.P., Kozlowski, R.W.H., Long, A.

“…We present infrared spectra of Mercury and the Moon in the wavelength range 0.7–5.3 μm obtained with the SpeX spectrograph at the NASA Infrared Telescope…”
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Techniques and methods in ground-based observation of Mercury by Cremonese, G., Warell, J., Harmon, J.K., Leblanc, F., Mendillo, M., Sprague, A.L.

“…Modern telescopes and equipments have permitted excellent ground-based observations of Mercury, despite its proximity to the Sun. This is one of the main…”
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Comparison of Laboratory Emission Spectra with Mercury Telescopic Data by Sprague, A.L., Roush, T.L.

“…Thermal emission spectra from four locations on Mercury's surface are compared with three new laboratory emission spectra: two spinels (gahnite and magnetite)…”
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Mars atmospheric water vapor abundance: 1991–1999, emphasis 1998–1999 by Sprague, A.L., Hunten, D.M., Doose, L.R., Hill, R.E., Boynton, W.V., Smith, M.D., Pearl, J.C.

“…Our ground-based measurements of martian atmospheric water vapor, made throughout L s = 34 ° to 249°, 24 September 1998 to 23 November 1999, during Mars year…”
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Mercury: Thermal Modeling and Mid-infrared (5–12 μm) Observations by Emery, J.P., Sprague, A.L., Witteborn, F.C., Colwell, J.E., Kozlowski, R.W.H., Wooden, D.H.

“…We present and use a new rough-surface thermal model to aid in the analysis of new mid-infrared spectral measurements of Mercury from 5–12.5 μm. The model…”
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Mid-Infrared (8.1–12.5 μm) Imaging of Mercury by Sprague, A.L., Deutsch, L.K., Hora, J., Fazio, G.G., Ludwig, B., Emery, J., Hoffmann, W.F.

“…The first images of Mercury to be obtained in thermal emission are discussed. Images at 22 wavelengths between 8.1 and 13.25 μm obtained with MIRAC…”
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Mercury: Sodium Atmospheric Enhancements, Radar-Bright Spots, and Visible Surface Features by Sprague, A.L., Schmitt, W.J., Hill, R.E.

“…Telescopic observations of Mercury's sodium atmosphere were made to test the theory that two mid-latitude radar-bright spots centered near ∼345° longitude and…”
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Mars atmospheric water vapor abundance: 1996–1997 by Sprague, A.L., Hunten, D.M., Doose, L.R., Hill, R.E.

“…Measurements of martian atmospheric water vapor made throughout L s = 18.0°–146.4° (October 3, 1996–July 12, 1997) show changes in Mars humidity on hourly,…”
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The Leonid Meteor Shower and the Lunar Sodium Atmosphere by Hunten, D.M., Cremonese, G., Sprague, A.L., Hill, R.E., Verani, S., Kozlowski, R.W.H.

“…Observations of lunar sodium were made on November 16–18, 1997, at Asiago and Mount Lemmon Observatories. A small enhancement was observed, and we suggest that…”
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Mars' South Polar Ar Enhancement: A Tracer for South Polar Seasonal Meridional Mixing by Sprague, A. L., Boynton, W. V., Kerry, K. E., Janes, D. M., Hunten, D. M., Kim, K. J., Reedy, R. C., Metzger, A. E.

“…The gamma ray spectrometer on the Mars Odyssey spacecraft measured an enhancement of atmospheric argon over southern high latitudes during autumn followed by…”
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Water Vapor Abundances over Mars North High Latitude Regions: 1996–1999 by Sprague, A.L, Hunten, D.M, Hill, R.E, Doose, L.R, Rizk, B

“…We present column abundances of water vapor in Mars' atmosphere over high north latitudes for L s 46°–146° during 1996–1997 and L s 34°–180° during 1998–1999…”
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Correction for Dust Opacity of Martian Atmospheric Water Vapor Abundances by Hunten, D.M., Sprague, A.L., Doose, L.R.

“…A method is presented to correct for the effects of dust opacity on the derivation of water-vapor abundances from observed spectral absorption lines. We show…”
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Mercury's feldspar connection mid-ir measurements suggest plagioclase by Sprague, A.L, Nash, D.B, Witteborn, F.C, Cruikshank, D.P

“…Mid-infrared (7.5 – 13.5 μm) spectra of Mercury at two equatorial longitudes obtained at the Infrared Telescope Facility (IRTF) at Mauna Kea Hawaii show…”
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Response to Comment on “Comparison of Laboratory Emission Spectra with Mercury Telescopic Data” by Melissa Lane by Sprague, A.L., Roush, T.L., Downs, R.T., Righter, K.

“…The laboratory spectrum published in Fig. 3 of A. L. Sprague and T. L. Roush (1998, Icarus 133, 174–183) is a mixture of magnetite and hematite (∼34–45%…”
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