scholarly journals Mesospheric Inversion Layers at Chatanika, Alaska (65°N, 147°W): Rayleigh lidar observations and analysis

2014 ◽  
Vol 119 (19) ◽  
pp. 11,235-11,249 ◽  
Author(s):  
Brita K. Irving ◽  
Richard L. Collins ◽  
Ruth S. Lieberman ◽  
Brentha Thurairajah ◽  
Kohei Mizutani
2019 ◽  
Vol 124 (2) ◽  
pp. 451-467 ◽  
Author(s):  
P. Llamedo ◽  
J. Salvador ◽  
A. Torre ◽  
J. Quiroga ◽  
P. Alexander ◽  
...  

1999 ◽  
Vol 51 (7-8) ◽  
pp. 825-832 ◽  
Author(s):  
S. P. Namboothiri ◽  
N. Sugimoto ◽  
H. Nakane ◽  
I. Matsui ◽  
Y. Murayama

2001 ◽  
Vol 28 (18) ◽  
pp. 3597-3600 ◽  
Author(s):  
Thomas J. Duck ◽  
Dwight P. Sipler ◽  
Joseph E. Salah ◽  
John W. Meriwether

2009 ◽  
Vol 27 (1) ◽  
pp. 373-379 ◽  
Author(s):  
S. Sridharan ◽  
S. Sathishkumar ◽  
K. Raghunath

Abstract. Rayleigh lidar observations of temperature structure and gravity wave activity were carried out at Gadanki (13.5° N, 79.2° E) during January–February 2006. A major stratospheric warming event occurred at high latitude during the end of January and early February. There was a sudden enhancement in the stratopause temperature over Gadanki coinciding with the date of onset of the major stratospheric warming event which occurred at high latitudes. The temperature enhancement persisted even after the end of the high latitude major warming event. During the same time, the UKMO (United Kingdom Meteorological Office) zonal mean temperature showed a similar warming episode at 10° N and cooling episode at 60° N around the region of stratopause. This could be due to ascending (descending) motions at high (low) latitudes above the critical level of planetary waves, where there was no planetary wave flux. The time variation of the gravity wave potential energy computed from the temperature perturbations over Gadanki shows variabilities at planetary wave periods, suggesting a non-linear interaction between gravity waves and planetary waves. The space-time analysis of UKMO temperature data at high and low latitudes shows the presence of similar periodicities of planetary wave of zonal wavenumber 1.


1998 ◽  
Vol 16 (2) ◽  
pp. 229-237 ◽  
Author(s):  
A. J. McDonald ◽  
L. Thomas ◽  
D. P. Wareing

Abstract. Observations made with the co-located Rayleigh lidar and MST radar systems at Aberystwyth (52.4°N, 4.1°W) in Wales and radiosondes from Valentia (51.9°N, 10.2°W) in Eire are used to investigate the changes in the vertical propagation of gravity waves during periods of 4 days in June 1995 and February 1993. In each month, the lidar observations show that the wave activity in the upper stratosphere and lower mesosphere changes between two pairs of days. The radar and radiosonde measurements indicate that mountain waves make no contribution to the changes in intensity. Instead, the changes seem to arise largely from the presence or absence of long-period waves with vertical wavelengths near 8 and 10 km in June and February, respectively. The influence of such waves on the vertical wavenumber spectra is examined and related to the evidence for convective instabilities provided by the temperature profiles.Key words. Rayleigh lidar · MST radar systems · Radiosondes · Gravity waves


2017 ◽  
Vol 35 (6) ◽  
pp. 1177-1194 ◽  
Author(s):  
Nelson Bègue ◽  
Nkanyiso Mbatha ◽  
Hassan Bencherif ◽  
René Tato Loua ◽  
Venkataraman Sivakumar ◽  
...  

Abstract. In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs) over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Réunion (20.8° S, 55.5° E) and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W) together with SABER observations at these two locations. MILs appear in 10 and 9.3 % of the observed temperature profiles recorded by Rayleigh lidar at Réunion and Mauna Loa, respectively. The parameters defining MILs show a semi-annual cycle over the two selected sites with maxima occurring near the equinoxes and minima occurring during the solstices. Over both sites, the maximum mean amplitude is observed in April and October, and this corresponds to a value greater than 35 K. According to lidar observations, the maximum and minimum mean of the base height ranged from 79 to 80.5 km and from 76 to 77.5 km, respectively. The MILs at Réunion appear on average ∼ 1 km thinner and ∼ 1 km lower, with an amplitude of ∼ 2 K higher than Mauna Loa. Generally, the statistical results for these two tropical locations as presented in this investigation are in fairly good agreement with previous studies. When compared to lidar measurements, on average SABER observations show MILs with greater amplitude, thickness and base altitudes of 4 K, 0.75 and 1.1 km, respectively. Taking into account the temperature error by SABER in the mesosphere, it can therefore be concluded that the measurements obtained from lidar and SABER observations are in significant agreement. The frequency spectrum analysis based on the lidar profiles and the 60-day averaged profile from SABER confirms the presence of the semi-annual oscillation where the magnitude maximum is found to coincide with the height range of the temperature inversion zone. This connection between increases in the semi-annual component close to the inversion zone is in agreement with most previously reported studies over tropics based on satellite observations. Results presented in this study confirm through the use of the ground-based Rayleigh lidar at Réunion and Mauna Loa that the semi-annual oscillation contributes to the formation of MILs over the tropical region.


2003 ◽  
Vol 108 (D24) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. Rajeev ◽  
K. Parameswaran ◽  
M. N. Sasi ◽  
Geetha Ramkumar ◽  
B. V. Krishna Murthy

2002 ◽  
Author(s):  
K. Parameswaran ◽  
K. Rajeev ◽  
M. N. Sasi ◽  
Geetha Ramkumar ◽  
B. V. Krishna Murthy ◽  
...  

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