SA32A-01 

Winter Upper Mesosphere Interannual Variability Determined from TIMED/SABER Measurements

* Winick, J R (jeremy.winick@hanscom.af.mil), Air Force Research Laboratory Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731-3010, United States Wintersteiner, P P (winters@arcon.com), Arcon Corporation, 260 Bear Hill Rd., Waltham, MA 02451, Picard, R H), Air Force Research Laboratory Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731-3010, United States Esplin, D), Utah State University, 4140 Old Main Hill, Logan, UT 84332, United States Mlynczak, M G), Atmospheric Sciences Division, NASA Langley Research Center, Hampton, VA 23681, United States Mertens, C J), Atmospheric Sciences Division, NASA Langley Research Center, Hampton, VA 23681, United States Russell, J M), Hampton University, Center for Atmospheric Sciences, Hampton, VA 23668, United States

Northern Hemisphere winter interannual variability in the troposphere and stratosphere has been studied for many years. TIMED/SABER data has allowed extension of this work into the middle and upper mesosphere, where large interannual variations are now also being observed. Retrieved OH volume emission rate (VER) profiles show that the altitude and brightness of the OH layer at northern high latitudes are distinctly different in the winters of 2004 and 2005. The mean altitude of the VER peak in the 70-80N latitude range is about 5 km lower in 2004 than 2005 for all night-time local times (20-06 hrs). The variation of the actual altitude with longitude is as much as 8 km that year. At the same time, retrieved SABER temperature is anomalously high in the mesosphere. We map the OH heights and temperature showing clear planetary wave patterns and strong correlation of low OH altitude with high temperatures. These patterns coincide with anomalous behavior in the stratosphere in which the cold polar vortex is displaced to about 45 km altitude. The lowered OH layer along with increased temperature indicates enhanced downward transport that can affect mesospheric and stratospheric chemistry. This behavior appears also in 2006, while 2002, 2003 and 2005 have OH emission heights near 87 km and temperature profiles in the more "normal" range.

SA32A-02 

Long term variability in migrating diurnal tide observed by the TIMED Doppler Interferometer (TIDI)

* Killeen, T L (killeen@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Wu, Q (qwu@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Solomon, S C (stans@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Ortland, D A (ortland@nwra.com), Northwest Research Associates, P.O.Box 3027, Bellevue, Wa 98009-3027, United States Skinner, W R (wskinner@umich.edu), Space Physics Research Lab. The University of Michigan, 2455 Hayward St., Ann Arbor, Mi 48109-2143, United States Niciejewski, R J (niciejew@umich.edu), Space Physics Research Lab. The University of Michigan, 2455 Hayward St., Ann Arbor, Mi 48109-2143, United States

We will examine the temporal variations of migrating diurnal tide in the mesosphere and lower thermosphere using the TIMED Doppler interferometer neutral wind data. The stratosphere QBO is the major source for the interannual variability of the migrating tide in the mesosphere and lower thermosphere. Buy examine the tidal variations using spectral analysis method, we plan to examine long term variations in the migrating diurnal tides beyond these related to the QBO. The TIDI data will allow us to examine the diurnal tide variation at different latitudes and altitudes. We will also study stratosphere observations in search of possible connections to changes in the stratosphere.

SA32A-03 

Nonmigrating diurnal tide long term variability observed by the TIMED Doppler Interferometer (TIDI)

* Wu, Q (qwu@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Killeen, T L (killeen@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Solomon, S C (stans@ucar.edu), HAO/NCAR, P.O.Box 3000, Boulder, Co 80307-3000, United States Ortland, D A (ortland@nwra.com), Northwest Research Associates, P.O.Box 3027, Bellevue, Wa 98009-3027, United States Skinner, W R (wskinner@umich.edu), Space Physics Research Lab. The University of Michigan, 2455 Hayward St., Ann Arbor, Mi 48109-2143, United States Niciejewski, R J (niciejew@umich.edu), Space Physics Research Lab. The University of Michigan, 2455 Hayward St., Ann Arbor, Mi 48109-2143, United States

We will examine the temporal variations of nonmigrating diurnal tide in the mesosphere and lower thermosphere using the TIMED Doppler interferometer neutral wind data. The stratosphere QBO is the major source for the interannual variability of migrating tide in the mesosphere and lower thermosphere. There are reports of the possible QBO related the nonmigrating diurnal tide interannual variabilities. Buy examine the tidal variations using spectral analysis method, we plan to examine long term variations in the nonmigrating diurnal tides beyond these related to the QBO. The TIDI data will allow us to examine the diurnal tide variation at different latitudes and altitudes. We will also examine changes in the mean zonal winds in search of possible connection between mean zonal wind and nonmigrating diurnal tides.

SA32A-04 

Diagnostic Analysis of the Eliassen-Palm Flux and Momentum Deposition in the Mesosphere and Lower Thermosphere by the SABER Measured Migrating Tides

* Zhu, X (xun.zhu@jhuapl.edu), Johns Hopkins University, Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, United States Yee, J), Johns Hopkins University, Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, United States Talaat, E R), Johns Hopkins University, Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, United States Mlynczak, M G), NASA/Langley, Langley Research Center, NASA 21 Langley Boulevard, Mail Stop 410B, Hampton, VA 23681, United States Russell, J M), Hampton University, Center for Atmospheric Sciences, Hampton University, 23 Tyler Street, Hampton, VA 23668,

Tidal and planetary-scale waves in temperatures and winds are the largest features of mesosphere and lower thermosphere (MLT) dynamics and its variability observable from satellites. Such waves play important roles in maintaining zonal mean atmospheric states, modulating the energetic balance, and transporting tracers in the MLT region. SABER on TIMED has been providing accurate and stable measurements of the temperature fields for over five years. The extracted zonal mean and tidal temperature fields from our newly developed algorithm are consistent with those derived from general circulation models. A spectral module is developed to derive tidal winds from the measured tidal temperature fields that effectively eliminates the error amplification near the apparent singularities. Using the SABER measured temperatures and the derived winds for both the zonal mean and migrating tidal fields we conduct a diagnostic analysis of the Eliassen-Palm flux and momentum deposition in the MLT region. Implications of the diagnostic results in association with the wave dynamics will be discussed.

SA32A-05 

Analysis of High-Latitude Neutral Wind in the Lower Thermosphere: Comparison of Fall and Spring Equinoxes

McCready, M (mary.mccready@sri.com), SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, United States * Saotome, R (Ryo.Saotome@trincoll.edu), Trinity College, 300 Summit Street, Hartford, CT 06106, United States Goncharenko, L (lpg@haystack.mit.edu), Massachusetts Institute of Technology, Haystack Observatory, Off Route 40, Westford, MA 01886, United States Hagan, M (hagan@ucar.edu), National Center for Atmospheric Research, High Altitude Observatory, PO Box 3000, Boulder, Co 80309, United States

Data obtained by the Sondrestrom incoherent scatter radar (67N, 309E) from campaigns during September 1-30, 2005 and March 6 - April 6, 2006 were analyzed to characterize neutral wind dynamics in the lower thermosphere at altitudes of 95-125 km. Lomb-Scargle spectral analysis revealed several significant waves in the data from both campaigns including 8-hour, semidiurnal and diurnal tides, as well as quasi 5-day and quasi-8 day planetary waves. Various harmonic components derived from the spectral analysis were then fit to the data over a range of altitudes in order to extract the amplitude and phase of the tidal components. During the spring equinox, a peak in the amplitude of the semi-diurnal tide is seen at around 110 km, in agreement with the Global Scale Wave Model. However, a peak seen in the diurnal tide for meridional equinox winds at 110 km is severely underestimated by the GSWM. For the meridional equinox winds in both the fall and spring, the amplitude of the semidiurnal tide is stronger than the diurnal component at altitudes below 105 km, while the opposite is shown to be true for higher altitudes. This is also in disagreement with the GSWM, which predicts a larger semi-diurnal component at all altitudes. Daily variations in the mean winds and amplitudes for both the diurnal and semi- diurnal components are also observed, especially in the semi-diurnal tide amplitudes near the spring equinox and the diurnal tide amplitudes in meridional equinox winds. The presence and phase progression of an 8-hour wave, also not predicted by theoretical models, is discussed as well.

SA32A-06 

Imaging of Atmospheric Gravity Waves in the Stratosphere and Upper Mesosphere using Satellite and Ground-Based Observations Over Australia During the TWP-ICE Campaign

* Hecht, J H (james.hecht@aero.org), Space Science Applications Laboratory, The Aerospace Corporation, PO Box 92957, Los Angeles, CA 90009, Aleaxander, M J (alexand@cora.nwra.com), NWRA/CoRA, 3380 Mitchell Lane, Boulder, CO 80301, Gelinas, L J (lynette.gelinas@aero.org), Space Science Applications Laboratory, The Aerospace Corporation, PO Box 92957, Los Angeles, CA 90009, Walterscheid, R L (richard.walterscheid@aero.org), Space Science Applications Laboratory, The Aerospace Corporation, PO Box 92957, Los Angeles, CA 90009,

The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua satellite can provide high spatial resolution (13.5 km pixels at nadir) images of infrared radiances originating near 40 km altitude over an approximately 1600-km cross track swath. Perturbations in these images are due to atmospheric gravity waves (AGWs). Traditionally, imaging of airglow emissions that originate near 90 km have been used to observe the horizontal structure of AGWs. Here we examine simultaneous images of AGWs using AIRS data obtained over Australia and airglow image data from the Aerospace camera located at Alice Springs, Australia. The period chosen is during the Tropical Warm Pool International Cloud Experiment (TWP-ICE) in late January/early February of 2006. During this period a tropical low that was associated with widespread deep convection and torrential rain established itself as an almost stationary feature situated between Darwin (12 S, 130 E) and Alice Springs (28 S, 134 E). We report on AGWs seen by both instruments, concentrating especially on the evening period of 1/31 UT where the Aqua overpass occurred during a period of active rainfall associated with this low, and clear skies over Alice Springs.

SA32A-07 

Consistent Satellite and Ground Based Observations and Model Simulations of Tides - CAWSES Global Tidal Campaign Results

Ward, W E (wward@unb.ca), Department of Physics, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada * Goncharenko, L (lpg@haystack.mit.edu), MIT Haystack Observatory, Off Route 40, Westford, MA 01886, United States Oberheide, J (joberh@uni-wuppertal.de), Physics Department, University of Wuppertal, Gauss Strasse 20, Wuppertal, 42097, Germany Nakamura, T (nakamura@rish.kyoto-u.ac.jp), Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Uji, Kyoto, 611- 0011, Japan Hoffmann, P (hoffmann@iap-kborn.de), Leibniz- Institute of Atmospheric Physics, Schloss-Straße 6, Kühlungsborn, 18255, Germany Chang, L (Loren.Chang@Colorado.EDU), Department of Aerospace Engineering Sciences University of Colorado, 429 UCB, Boulder, CO 80309-0429, United States Du, J (p531w@unb.ca), Department of Physics, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada Greiger, N (grieger@iap-kborn.de), Leibniz- Institute of Atmospheric Physics, Schloss-Straße 6, Kühlungsborn, 18255, Germany Haefele, A (haefele@mw.iap.unibe.ch), Institute of Applied Physics, University of Bern, Sidlerstr. 5, Bern, 3012, Switzerland Wang, D (dwang@uunb.ca), Department of Physics, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada Shei, C (joeshe@lamar.colostate.edu), Colorado State University, 1875 Campus Delivery, Fort Collins, CO 80523, United States Yuan, T (titus@lamar.colostate.edu), Colorado State University, 1875 Campus Delivery, Fort Collins, CO 80523, United States

A persistent issue in the study of atmospheric tides has been differences in tidal signatures deduced from different observing systems and models. Recent analyses during the Second CAWSES Global Tidal Campaign Workshop show consistency between satellite observations (primarily from TIMED), ground based radars, lidar wind measurements and model analyses (likely) for the first time. This agreement required suitable reconstruction of components from the satellite and model analyses at the location of the ground based station. In this paper, we describe the campaigns and observations, summarize the analysis process and illustrate the extent to which tidal signatures from the various data types agree.

SA32A-08 

Extended CMAM: Impacts of thermospheric neutral and ion chemistry on the middle atmosphere.

* Beagley, S (beagley@nimbus.yorku.ca), centre of Earth and Space Science, York University 4700 Keele Street, Toronto, ON M3J 1P3, Canada McConnell, J C (jcmcc@yorku.ca), centre of Earth and Space Science, York University 4700 Keele Street, Toronto, ON M3J 1P3, Canada Fomichev, V (victor@nimbus.yorku.ca), centre of Earth and Space Science, York University 4700 Keele Street, Toronto, ON M3J 1P3, Canada Semeniuk, K (kirill@nimbus.yorku.ca), centre of Earth and Space Science, York University 4700 Keele Street, Toronto, ON M3J 1P3, Canada Jonsson, A I (andreas@atmosp.physics.utoronto.ca), University of Toronto, University of Toronto 60 St. George Street, Toronto, ON M5S 1A7, Canada Garcia Munoz, A (antonio.garcia-munoz@anu.edu.au), Australian National University, Canberra, Canberra, ACT ACT 0200, Australia McLandress, C (charles@mam.atmosp.physics.utoronto.ca), University of Toronto, University of Toronto 60 St. George Street, Toronto, ON M5S 1A7, Canada Shepherd, T (tgs@atmosp.physics.utoronto.ca), University of Toronto, University of Toronto 60 St. George Street, Toronto, ON M5S 1A7, Canada

The Canadian Middle Atmosphere Model (CMAM) is a chemistry-climate model with comprehensive gas phase and heterogeneous chemistry for middle atmosphere applications with a vertical domain from the surface to about 95 km. The extended version of CMAM has a vertical domain which encompasses the thermosphere and a nominal top at about 250 km, the exact height depending on solar cycle related EUV heating. Certain improvements have been reported in the dynamical version of extended CMAM (Fomichev et al., 2002). In this report we have added thermospheric gas phase and ion-molecule chemistry to study solar cycle effects of changing EUV solar flux and also auroral ionization (Semeniuk et al., 2007). The physical processes necessary to add have included molecular diffusion for minor and major species (N2, O2, and O) and we allow the model to internally derive its own mean-molecular mass and related parameters such as gas-constant in a consistent manner: 99% of the atmospheric gases are advected. The model has also includes improvements to the earlier extended dynamical CMAM version with changes to the GWD schemes. We have run an 8 year time-slice for assessment and the results will be presented here: current analysis indicates quite a good agreement with MSIS and satellite measurements. We will also present results to indicate the impact of a realistic thermosphere on the middle atmosphere as opposed to a CMAM version with a standard vertical domain at 95 km where boundary conditions are stipulated.

Author(s) (2007), Title, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract #####-##.