scholarly journals Temperature tele‐connections between the tropical and polar middle atmosphere in the Southern Hemisphere during the 2010 minor sudden stratospheric warming

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Sunkara Eswaraiah ◽  
Changsup Lee ◽  
Wonseok Lee ◽  
Yong Ha Kim ◽  
Kondapalli Niranjan Kumar ◽  
...  
2013 ◽  
Vol 31 (10) ◽  
pp. 1709-1719
Author(s):  
N. Mbatha ◽  
V. Sivakumar ◽  
H. Bencherif ◽  
S. Malinga

Abstract. Using absorption data measured by imaging riometer for ionospheric studies (IRIS) located at the South Africa National Antarctic Expedition (SANAE), Antarctica (72° S, 3° W), we extracted the parameters of gravity waves (GW) of periods between 40 and 50 min during late winter/spring of the year 2002, a period of the unprecedented major sudden stratospheric warming (SSW) in the Southern Hemisphere middle atmosphere. During this period, an unprecedented substantial increase of temperature by about 25–30 K throughout the stratosphere was observed. During the period of the occurrence of the major stratospheric warming, there was a reduction of both the GW horizontal phase speeds and the horizontal wavelengths at 90 km. The GW phase speeds and horizontal wavelengths were observed to reach minimum values of about 7 m s−1 and 19 km, respectively, while during the quiet period the average value of the phase speed and horizontal wavelength was approximately 23 m s−1 and 62 km, respectively. The observed event is discussed in terms of momentum flux and also a potential interaction of gravity waves, planetary waves and mean circulation.


2020 ◽  
Vol 65 (21) ◽  
pp. 1800-1802 ◽  
Author(s):  
Xiaocen Shen ◽  
Lin Wang ◽  
Scott Osprey

2020 ◽  
Author(s):  
Y.Y. Kulikov ◽  
◽  
A.F. Andriyanov ◽  
V.G. Ryskin ◽  
V.M. Demkin ◽  
...  

We present data continuous series of microwave observations of the middle atmosphere in winters 2017-2018, 2018-2019 and 2019-2020. In each of these winters sudden stratospheric warming were marked.Measurements were carried out with the help of mobile ozonemeter (observation frequency 110836.04 MHz), which was established at Polar Geophysical Institute in Apatity (67N, 33E). The parameters of the device allow to measure a spectrum of the ozone emission line for time about 15 min a precision of 2%. On the measured spectra were appreciated of ozone vertical profiles in the layer of 22 60 km which were compared to satellite data MLS/Aura and with the data of ozonesonde at station Sodankyla (67N, 27E). The microwave data on the behavior of mesospheric ozone (altitude 60 km) indicate the presence of bothphotochemical and dynamic components in its changes.


2021 ◽  
Author(s):  
Guangyu Liu ◽  
Toshihiko Hirooka ◽  
Nawo Eguchi ◽  
Kirstin Krüger

Abstract. This study analyzes the Japanese 55-year Reanalysis (JRA-55) dataset from 2002 to 2019 to examine the sudden stratospheric warming event that occurred in the Southern Hemisphere (SH) in 2019 (hereafter referred to as SSW2019). Strong warming at the polar cap and decelerated westerly winds were observed, but since there was no reversal of westerly winds to easterly winds at 60° S in the middle to lower stratosphere, the SSW2019 is classified as a minor warming event. The results show that quasi-stationary planetary waves of zonal wavenumber 1 developed during the SSW2019. The strong vertical component of the Eliassen–Palm flux with zonal wavenumber 1 is indicative of pronounced propagation of planetary waves to the stratosphere. The wave driving in September 2019 shows that the values are larger than those of the major SSW event in 2002 (hereafter referred to as SSW2002). Since there was no pronounced preconditioning (as in SSW2002) and the polar vortex was already strong before the SSW2019 occurred, a major disturbance of the polar vortex was unlikely to have taken place. The strong wave driving in SSW2019 occurred in high latitudes. Waveguides (i.e., positive values of the refractive index) are found at high latitudes in the upper stratosphere during the warming period, which provided favorable conditions for quasi-stationary planetary waves to propagate upward and poleward.


2009 ◽  
Vol 27 (3) ◽  
pp. 975-987 ◽  
Author(s):  
D. Pancheva ◽  
P. Mukhtarov ◽  
B. Andonov

Abstract. This paper is focused on the nonmigrating tidal activity seen in the SABER/TIMED temperatures that is related to the major sudden stratospheric warming (SSW) taking place in the Arctic winter of 2003/2004. The emphasis is on the nonmigrating diurnal tides observed in the stratosphere and lower mesosphere which is usually accepted to be insignificant in comparison with that in the upper mesosphere and thermosphere. By using different independent spectral methods we found a significant amplification in December–January of the following nonmigrating 24-h tides: zonally symmetric (s=0), eastward propagating with zonal wavenumber 1 (E1), and westward propagating with zonal wavenumbers 2 and 3 (W2 and W3) tides. It has been found that the double peak nonmigrating tidal amplifications located in the stratosphere (~40 km) and in the lower mesosphere (~70 km) are a consequence of the maintained hydrostatic relation. By detailed comparison of the evolution and spatial structure of the nonmigrating diurnal tides with those of the migrating diurnal tide and stationary planetary waves (SPWs) evidence for a SPW-migrating tide interaction as a source of nonmigrating tides has been presented. Therefore, the nonmigrating 24-h tides turn out to be an important component of the middle atmosphere dynamics during the major SSW in the Arctic winter of 2003/2004.


2021 ◽  
Author(s):  
Jack Wang ◽  
Scott Palo ◽  
Jeffrey Forbes ◽  
John Marino ◽  
Tracy Moffat-Griffin

<div> <p>An unusual sudden stratospheric warming (SSW) occurred in the Southern hemisphere in September 2019. Ground-based and satellite observations show the presence of a transient westward-propagating quasi-10 day planetary wave with zonal wavenumber one during the SSW. The planetary wave activity maximizes in the MLT region approximately 10 days after the SSW onset. Analysis indicates the quasi-10 day planetary wave is symmetric about the equator which is contrary to theory for such planetary waves. </p> </div><div> <p>Observations from MLS and SABER provide a unique opportunity to study the global structure and evolution of the symmetric quasi-10 day wave with observations of both geopotential height and temperature during these unusual atmospheric conditions. The space-based measurements are combined with meteor radar wind measurements from Antarctica, providing a comprehensive view of the quasi-10 day wave activity in the southern hemisphere during this SSW. We will also present the results of our mesospheric and lower thermospheric analysis along with a preliminary analysis of the ionospheric response to these wave perturbations.</p> </div>


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