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Comparisons Of Long-Term Trends And Variability In The Middle Atmosphere, Troy Wynn, Joshua P. Herron, Vincent B. Wickwar

Posters

The USU Rayleigh Lidar (41.74°N 111.81°W) has been regularly used to measure temperatures in the middle atmosphere from 45 to 90 km. It is well suited for nightly observation; provides excellent vertical temperature resolution; and does not need external calibration. It began operation in August 1993 and a dataset spanning more than ten years has been collected. The analysis here includes 593 nightly temperature profiles from September 1993 through July 2003.

With many sources of variation in the atmosphere, all temperature effects cannot be easily detected. The largest source of temperature variation, and the easiest to measure, is the annual …

Rayleigh-Lidar Observations Of Mesospheric Mid-Latitude Density Climatology Above Utah State University, Eric M. Lundell, Vincent B. Wickwar

Posters

Data from Rayleigh lidars have been used extensively to derive temperatures in the mesospheric region of the atmosphere. However, these data have not been used extensively in a similar way to derive neutral densities. We report on one such mid-latitude, density climatology between 45 and ~90 km, based on nearly 600 good nights of observations carried out since 1993 at the Atmospheric Lidar Observatory (ALO) at Utah State University (41.7°N 111.8°W). They produce relative density profiles that are then normalized at 45 km to an empirical model, in this case the MSISe00 model. Despite this normalization, significant differences are found …

Seasonal Variations Of The Gravity Wave Momentum Flux In The Antarctic Mesosphere And Lower Thermosphere, P. J. Espy, G. O.L. Jones, G. R. Swenson, J. Tang, Michael J. Taylor

All Physics Faculty Publications

Airglow imager and dynasonde/imaging Doppler interferometer (IDI) radar wind measurements at Halley Station, Antarctica (75.6S, 26.6W) have been used to estimate the seasonal variation of the vertical fluxes of horizontal momentum carried by highfrequency atmospheric gravity waves. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from sodium (Na) airglow imager data collected during the austral winter seasons of 2000 and 2001. These were combined with wind velocity variances from coincident radar measurements to estimate the daily averaged upper limit of the vertical flux of horizontal momentum due to gravity waves. The resulting momentum flux at the …

Results From The Middle Atmosphere With The Rayleigh-Scatter Lidar At Usu’S Atmospheric Lidar Observatory, Vincent B. Wickwar, Joshua P. Herron, Troy A. Wynn, Eric M. Lundell

Posters

No abstract provided.

Comparisons Of Long-Term Trends And Variability In The Middle Atmosphere, Troy Wynn, Joshua P. Herron, Vincent B. Wickwar

Posters

Rayleigh Lidar is routinely used to measure temperatures in the middle atmosphere from 45 to 90 km. It is well adapted for nightly observation, provides excellent vertical temperature resolution, and does not need external calibration. The USU Rayleigh Lidar (41.74°N 111.81°W) dataset spans more than ten years from September 1993 to July 2003 with 62 monthly profiles (about 5 years of data) spread over that period.

With many sources of variation in the atmosphere, all temperature effects cannot be detected. The largest source, and the easiest to measure, is the seasonal variation. In addition there are semiannual variation, secular trends, …

Mesospheric Mid-Latitude Density Climatology Above Utah State University, Eric M. Lundell, Vincent B. Wickwar

Posters

Lidars have been used extensively to derive temperatures, but not absolute densities, in the mesospheric region of the atmosphere. We used observations since 1993 with the Rayleigh- scatter lidar at the Atmospheric Lidar Observatory (ALO) at Utah State University (41.7oN, 111.8oW) to create an absolute density climatology between 45 and ~95 km. The observations provide profiles of relative density to which an absolute scale is attached by normalizing the profiles at 45 km to the densities in the MSISe00 empirical model. We examine the density variations on several time scales—during the climatological year, from year to year, and over several …

Atmospheric Lidar Observatory (Alo) Ten-Year Mesospheric Temperature Climatology, Joshua P. Herron, Vincent B. Wickwar

Posters

The Rayleigh-scatter lidar at the Atmospheric Lidar Observatory (ALO) on the Utah State University (USU) (41.7°N, 111.8°W) campus has been in operation since 1993. The temperature database now contains over ten years of Rayleigh-scatter temperatures. A multi-year temperature climatology has been calculated from these observations along with the RMS and interannual variability. These temperatures and the climatology are currently being used in a number of mesospheric studies, including mesospheric inversion layers, tides, planetary waves, cyclical variations, trends, longitudinal comparisons, and validation studies.

Examples Of Alo Results, Vincent B. Wickwar, Joshua P. Herron, Karen M. Nelson, Troy A. Wynn, Kristina Thomas, Eric M. Lundell

Presentations

No abstract provided.

Tomex: Mesospheric And Lower Thermospheric Diffusivities And Instability Layers, R. L. Bishop, M. F. Larsen, J. H. Hecht, Alan Z. Liu, C. S. Gardner

Physical Sciences - Daytona Beach

The Turbulent Oxygen Mixing Experiment (TOMEX), which was carried out at White Sands Missile Range in New Mexico on 26 October 2000, included a rocketborne trimethyl aluminum (TMA) chemical tracer experiment. The subsequent TMA trails provided detailed information about the horizontal neutral wind, turbulence, and diffusivity properties of the atmosphere between approximately 85 and 140 km altitude. Measurements with the University of Illinois Na wind/temperature lidar located at the Starfire Optical Range, NM, provided a detailed time history of the stability properties between 85 and 105-km altitude, including high-resolution wind and temperature measurements prior to and during the chemical tracer …

Mesospheric Temperature Climatology Above Utah State University, Joshua P. Herron

Physics

A Rayleigh-scatter lidar has been in operation at Utah State University (41.7o N, 111.8 ° W) starting in September 1993 until the present (October 2003). The return profiles from the atmosphere have been analyzed to provide temperature measurements of the middle atmosphere from 45 to 90 km. Various methods of averaging were used to construct a temperature climatology of the region based on these observations. The data analysis algorithm has been critically analyzed to find possible sources of error, and has been compared to an independently derived technique. The resulting temperatures have been compared to other mid-latitude lidars with good …