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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
On The Variability Of Mesospheric Oh Emission Profiles, Romina Nikoukar, Gary R. Swenson, Alan Z. Liu, Farzad Kamalabadi
On The Variability Of Mesospheric Oh Emission Profiles, Romina Nikoukar, Gary R. Swenson, Alan Z. Liu, Farzad Kamalabadi
Physical Sciences - Daytona Beach
Mesospheric OH radiance limb profiles measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) spacecraft were inverted to yield altitude profiles of OH volume emission rates. The Abel inversion results of two months of data (from 1 June to 31 July 2004) were analyzed for the layer mean and standard deviation as a function of latitude and local time. Statistical analysis of SABER data shows that the global difference between the mean and standard deviation profiles for the OH(vu = 7, 8, 9; ∆v …
Characteristics Of Short-Period Wavelike Features Near 87 Km Altitude From Airglow And Lidar Observations Over Maui, J. H. Hecht, A. Z. Liu, R. L. Walterscheid, S. J. Franke, R. J. Rudy, M. J. Taylor, P. -D. Pautet
Characteristics Of Short-Period Wavelike Features Near 87 Km Altitude From Airglow And Lidar Observations Over Maui, J. H. Hecht, A. Z. Liu, R. L. Walterscheid, S. J. Franke, R. J. Rudy, M. J. Taylor, P. -D. Pautet
Physical Sciences - Daytona Beach
Small-scale (less than 15 km horizontal wavelength) wavelike structures known as ripples are a common occurrence in OH airglow images. Recent case studies attribute their origin to the presence of either convective or dynamical instabilities. However, little is known about their frequency of occurrence and period. The Maui-MALT Observatory, located at Mt. Haleakala, is instrumented with a Na wind/temperature lidar, which allows the determination of whether the atmosphere is dynamically or convectively unstable, and a fast OH airglow camera which takes images every 3 s with a sensitivity high enough to see the ripples. This study reports on 2 months …
Measurements Of Mesospheric Sodium Abundance Above The Hawaiian Islands, Lewis C. Roberts, Jr., L. William Bradford, Christopher R. Neyman, Alan Z. Liu
Measurements Of Mesospheric Sodium Abundance Above The Hawaiian Islands, Lewis C. Roberts, Jr., L. William Bradford, Christopher R. Neyman, Alan Z. Liu
Physical Sciences - Daytona Beach
Laser guide stars have increased the utility of adaptive optics systems by expanding the number of observable objects. The most common type of laser excites sodium in the mesosphere, and mesospheric sodium density is key to the performance of the laser. While a variety of observatories have conducted studies of the mesospheric sodium density, there are no published studies from Hawaii, which is home to some of the largest telescopes in the world. This paper presents mesospheric sodium densities measured by the University of Illinois lidar for 165 hr spanning 25 nights over 3 years. The mean sodium column density …
O(1s), Oh, And O2(B) Airglow Layer Perturbations Due To Agws And Their Implied Effects On The Atmosphere, Fabio Vargas, Gary Swenson, Alan Liu, Delano Gobbi
O(1s), Oh, And O2(B) Airglow Layer Perturbations Due To Agws And Their Implied Effects On The Atmosphere, Fabio Vargas, Gary Swenson, Alan Liu, Delano Gobbi
Physical Sciences - Daytona Beach
The O(1S) (green line) night airglow emission in response to atmospheric gravity wave (AGW) perturbations was simulated with a linear, one-dimensional model. The results were combined with previously modeled O2(b, 0–1) atmospheric band and OH Meinel band emission response (Liu and Swenson, 2003) to derive amplitude and phase relations among multiple airglow layers in response to gravity waves with various intrinsic parameters and damping rates (β). The simulations show that the vertical profile of the standard deviation of the perturbed green line volume emission rate (VER) has a centroid altitude that is 3 km …
Seasonal Variations Of The Vertical Fluxes Of Heat And Horizontal Momentum In The Mesopause Region At Starfire Optical Range, New Mexico, Chester S. Gardner, Alan Z. Liu
Seasonal Variations Of The Vertical Fluxes Of Heat And Horizontal Momentum In The Mesopause Region At Starfire Optical Range, New Mexico, Chester S. Gardner, Alan Z. Liu
Physical Sciences - Daytona Beach
Lidar observations of wind and temperature profiles between 85 and 100 km, conducted at the Starfire Optical Range (SOR), New Mexico, are used to characterize the seasonal variations of the vertical fluxes of heat and horizontal momentum and their relationships to gravity wave activity in this region. The wind and temperature variances exhibit strong 6-month oscillations with maxima during the summer and winter that are about 3 times larger than the spring and fall minima. The vertical heat flux also exhibits strong 6-month oscillations with maximum downward flux during winter and summer. The downward heat flux peaks near 88 km …
Investigation Of A “Wall” Wave Event, Feng Li, Gary R. Swenson, Alan Z. Liu, Michael Taylor, Yucheng Zhao
Investigation Of A “Wall” Wave Event, Feng Li, Gary R. Swenson, Alan Z. Liu, Michael Taylor, Yucheng Zhao
Physical Sciences - Daytona Beach
A bright airglow event was observed at Maui, Hawaii, on the night of 11–12 August 2004 with multiple instruments including a Na wind/temperature lidar, an airglow imager, and a mesospheric temperature mapper. The characteristics of this event were investigated with measurements from these instruments. Analysis showed that this event was caused by a large-amplitude, upward-propagating gravity wave with a period of about 4–5 hours and a vertical wavelength of about 20 km, i.e., a “wall” wave. This wall wave induced dramatic changes in temperature (60 K), airglow intensity (doubled in the OH and tripled in the O2 emissions), and …