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JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D09S03, doi:10.1029/2004JD004891, 2005

Nocturnal thermal structure of the mesosphere and lower thermosphere region at Maui, Hawaii (20.7°N), and Starfire Optical Range, New Mexico (35°N)

Xinzhao Chu

Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA


Chester S. Gardner

Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA


Steven J. Franke

Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA


Abstract

The nighttime thermal structure of the mesosphere and lower thermosphere (MLT) region at the Starfire Optical Range (SOR), New Mexico (35.0°N, 106.5°W), and at Maui, Hawaii (20.7°N, 156.3°W), are characterized using Na lidar observations. Both locations exhibit mesospheric temperature inversion layers (MILs) between 85 and 100 km that are not predicted by the MSIS-00 model. The amplitudes of the Maui MILs (∼5.8 K) are about half of those at SOR (∼9.8 K), and the Maui MILs have a smaller width (∼11.1 km) compared to the SOR MILs (∼14.5 km). The Maui lidar temperatures are generally warmer than the MSIS-00 predictions, while the SOR lidar data are comparable to the MSIS-00, except in the MIL altitude range. Both SOR and Maui mesopause temperatures are coldest in midsummer and are warmest during the mesopause transition periods. However, the Maui mesopause is warmer than the SOR, and the amplitude of the mesopause temperature variations at Maui (∼9 K) is much smaller than at SOR (∼19 K). Two distinct levels of mesopause altitudes are clearly shown in the SOR seasonal data with a low altitude around 86.5 km in summer (May through August) and a high altitude around 101 km during the rest of the year. Abrupt transitions between the two stable levels occur in early May and early September. The lidar measurements indicate a low mesopause altitude near 87.5 km in July at Maui when averaging over a 10-hour period centered at local midnight.

Received 10 April 2004; accepted 12 November 2004; published 29 January 2005.

Keywords: lidar; thermal structure; mesosphere and lower thermosphere region.

Index Terms: 0350 Atmospheric Composition and Structure: Pressure, density, and temperature; 3360 Atmospheric Processes: Remote sensing; 3334 Atmospheric Processes: Middle atmosphere dynamics (0341, 0342); 3319 Atmospheric Processes: General circulation (1223); 0394 Atmospheric Composition and Structure: Instruments and techniques.

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 3153422 bytes)

Citation: Chu, X., C. S. Gardner, and S. J. Franke (2005), Nocturnal thermal structure of the mesosphere and lower thermosphere region at Maui, Hawaii (20.7°N), and Starfire Optical Range, New Mexico (35°N), J. Geophys. Res., 110, D09S03, doi:10.1029/2004JD004891.