scholarly journals Overview of the temperature response in the mesosphere and lower thermosphere to solar activity

2008 ◽  
Vol 46 (3) ◽  
Author(s):  
G. Beig ◽  
J. Scheer ◽  
M. G. Mlynczak ◽  
P. Keckhut
2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Igor Mingalev ◽  
Victor Mingalev

The nonhydrostatic model of the global neutral wind system of the earth’s atmosphere, developed earlier in the Polar Geophysical Institute, is utilized to investigate how solar activity affects the formation of the large-scale global circulation of the mesosphere and lower thermosphere. The peculiarity of the utilized model consists in that the internal energy equation for the neutral gas is not solved in the model calculations. Instead, the global temperature field is assumed to be a given distribution, that is, the input parameter of the model. Moreover, in the model calculations, not only the horizontal components but also the vertical component of the neutral wind velocity is obtained by means of a numerical solution of a generalized Navier-Stokes equation for compressible gas, so the hydrostatic equation is not applied. The simulation results indicate that solar activity ought to influence considerably on the formation of global neutral wind system in the mesosphere and lower thermosphere. The influence is conditioned by the vertical transport of air from the lower thermosphere to the mesosphere and stratosphere. This transport may be rather different under distinct solar activity conditions.


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 ◽  
...  

1999 ◽  
Vol 24 (11) ◽  
pp. 1571-1576 ◽  
Author(s):  
P.J.S. Williams ◽  
N.J. Mitchell ◽  
A.G. Beard ◽  
V.St.C. Howells ◽  
H.G. Muller

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