scholarly journals A comparison of mesosphere and lower thermosphere neutral winds as determined by meteor and medium-frequency radar at 70°N

Radio Science ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
C. M. Hall ◽  
T. Aso ◽  
M. Tsutsumi ◽  
S. Nozawa ◽  
A. H. Manson ◽  
...  
2004 ◽  
Vol 75 (7) ◽  
pp. 2346-2350 ◽  
Author(s):  
Yoshiko Koizumi ◽  
Manabu Shimoyama ◽  
Koh-Ichiro Oyama ◽  
Yasuhiro Murayama ◽  
Toshitaka Tsuda ◽  
...  

2011 ◽  
Vol 29 (4) ◽  
pp. 623-629 ◽  
Author(s):  
N. Venkateswara Rao ◽  
Y. Shibagaki ◽  
T. Tsuda

Abstract. We study short period gravity waves (20–120 min) in the equatorial Mesosphere and Lower Thermosphere (MLT) using a Medium Frequency (MF) radar at Pameungpeuk (7.4° S, 107.4° E), Indonesia. In particular, we study local time and seasonal variation of the gravity wave variance and its relation to tropical convection. The gravity wave variance at 88 km enhances between 20:00 LT and 07:00 LT, with a peak at 02:00–03:00 LT. The enhancement is mainly observed during February–April and September–October and shows inter-annual variability. Convective activity over the same location persists from 16:00–21:00 LT with a peak activity ~18:00 LT and enhances between November–April. Time delay between the peak of convection and that of gravity wave activity ranges 1–15 h, which is consistent with theoretical calculations and previous reports based on reverse ray tracing analysis.


1997 ◽  
Vol 102 (A6) ◽  
pp. 11507-11519 ◽  
Author(s):  
Q. H. Zhou ◽  
M. P. Sulzer ◽  
C. A. Tepley ◽  
C. G. Fesen ◽  
R. G. Roble ◽  
...  

2005 ◽  
Vol 62 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Rolando R. Garcia ◽  
Ruth Lieberman ◽  
James M. Russell ◽  
Martin G. Mlynczak

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.


2015 ◽  
Vol 56 (7) ◽  
pp. 1354-1365 ◽  
Author(s):  
Xin Yao ◽  
Tao Yu ◽  
Biqiang Zhao ◽  
You Yu ◽  
Libo Liu ◽  
...  

1994 ◽  
Vol 56 (13-14) ◽  
pp. 1731-1752 ◽  
Author(s):  
Yu.I. Portnyagin ◽  
N.A. Makarov ◽  
R.P. Chebotarev ◽  
A.M. Nikonov ◽  
E.S. Kazimirovsky ◽  
...  

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