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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
Alan Z Liu
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 …
First Observations Of Long-Lived Meteor Trains With Resonance Lidar And Other Optical Instruments, M. C. Kelley, C. Gardner, J Drummond, T Armstrong, A Liu, Chu G. Papen, C Kruschwitz, P. Loughmiller, B Grime, J. Engelman
First Observations Of Long-Lived Meteor Trains With Resonance Lidar And Other Optical Instruments, M. C. Kelley, C. Gardner, J Drummond, T Armstrong, A Liu, Chu G. Papen, C Kruschwitz, P. Loughmiller, B Grime, J. Engelman
Alan Z Liu
In November 1998 the earth passed through a maximum in the cometary material responsible for the yearly Leonids meteor shower. The meteor storm event produced numerous examples of long-lived chemiluminescent trails--visible to the naked eye over New Mexico, where a major observation campaign was centered. One trail was detected for over an hour with a CCD camera employing a narrow sodium filter, and many others were observed for over ten minutes each. For the first time, sodium densities in such trails were measured while also being imaged in sodium light. We have verified one source of long-lived light emissions--a sodium-catalyzed …
Lidar Observations Of Elevated Temperatures In Bright Chemiluminescent Meteor Trails During The 1998 Leonid Shower, Xinzhao Chu, Alan Z. Liu, George Papen, Chester S. Gardner
Lidar Observations Of Elevated Temperatures In Bright Chemiluminescent Meteor Trails During The 1998 Leonid Shower, Xinzhao Chu, Alan Z. Liu, George Papen, Chester S. Gardner
Alan Z Liu
Seven persistent trails associated with bright fireballs were probed with a steerable Na wind/temperature lidar at Starfire Optical Range, NM during the 17/18 Nov peak of the 1998 Leonid meteor shower. These chemiluminescence trails were especially rich in Na. The average Na abundance within the trails was 52% of the background Na layer abundance, which suggests that the corresponding masses of the meteors were from 1 g up to 1 kg. CCD images show that the chemiluminescent emissions (including Na and OH) are confined to the walls of a tube, which expands with time by molecular diffusion. Lidar profiles within …
Comparison Of Meteor Radar And Na Doppler Lidar Measurements Of Winds In The Mesopause Region Above Maui, Hawaii, S. J. Franke, X. Chu, A. Z. Liu, W. K. Hocking
Comparison Of Meteor Radar And Na Doppler Lidar Measurements Of Winds In The Mesopause Region Above Maui, Hawaii, S. J. Franke, X. Chu, A. Z. Liu, W. K. Hocking
Alan Z Liu
The coincident measurements span 96 hours and altitudes between 80 and 100 km. Statistical comparisons are carried out on radar/lidar winds with 1 hour and 4 km time and height resolution, respectively. The RMS radar/lidar wind component differences observed in this study are in the range 12–17 m/s at altitudes below 96 km. This is smaller than the RMS differences observed in a previous Na lidar and meteor radar comparison. Lidar wind component variances exceed radar variances, and radar/lidar covariance, is nearly equal to the radar variance. Excess variance observed by the lidar is consistent with the fact that the …
Observations Of Persistent Leonid Meteor Trails 2. Photometry And Numerical Modeling, C. A. Kruschwitz, M. C. Kelley, C. S. Gardner, G. Swenson, A. Z. Liu, X. Chu, J. D. Drummond, B. W. Grime, W. T. Armstrong, J. M. C. Plane, P. Jenniskens
Observations Of Persistent Leonid Meteor Trails 2. Photometry And Numerical Modeling, C. A. Kruschwitz, M. C. Kelley, C. S. Gardner, G. Swenson, A. Z. Liu, X. Chu, J. D. Drummond, B. W. Grime, W. T. Armstrong, J. M. C. Plane, P. Jenniskens
Alan Z Liu
During the 1998 Leonid meteor shower, multi-instrument observations of persistent meteor trains were made from the Starfire Optical Range on Kirtland Air Force Base, New Mexico, and from a secondary site in nearby Placitas, New Mexico. The University of Illinois Na resonance lidar measured the Na density and temperature in the trains, while various cameras captured images and videos of the trains, some of which were observed to persist for more than 30 min. The Na density measurements allow the contribution of Na airglow to the observed train luminescence to be quantified for the first time. To do this, persistent …