scholarly journals Inertia-gravity waves in the troposphere and lower stratosphere associated with a jet stream exit region

1999 ◽  
Vol 17 (1) ◽  
pp. 115 ◽  
Author(s):  
L. Thomas ◽  
R. M. Worthington ◽  
A. J. McDonald
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Jet Stream ◽  
Exit Region ◽  
Inertia Gravity Waves

scholarly journals Inertia-gravity waves in the troposphere and lower stratosphere associated with a jet stream exit region

1999 ◽  
Vol 17 (1) ◽  
pp. 115-121 ◽  
Author(s):  
L. Thomas ◽  
R. M. Worthington ◽  
A. J. McDonald
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
Vertical Shear ◽  
Jet Stream ◽  
Mesoscale Meteorology ◽  
Perturbation Velocity ◽  
Waves And Tides ◽  
Radar Measurements ◽  
Inertia Gravity Waves

Abstract. Radar measurements at Aberystwyth (52.4° N, 4.1° W) of winds at tropospheric and lower stratospheric heights are shown for 12-13 March 1994 in a region of highly curved flow, downstream of the jet maximum. The perturbations of horizontal velocity have comparable amplitudes in the troposphere and lower stratosphere with downward and upward phase propagation, respectively, in these two height regions. The sense of rotation with increasing height in hodographs of horizontal perturbation velocity derived for hourly intervals show downwards propagation of energy in the troposphere and upward propagation in the lower stratosphere with vertical wavelengths of 1.7 to 2.3 km. The results indicate inertia-gravity waves propagating in a direction similar to that of the jet stream but at smaller velocities. Some of the features observed contrast with those of previous observations of inertia-gravity waves propagating transverse to the jet stream. The interpretation of the hodographs to derive wave parameters has taken account of the vertical shear of the background wind transverse to the direction of wave propagation.Key words. Meteorology and atmospheric dynamics (mesoscale meteorology; middle atmosphere dynamics; waves and tides)

An investigation into the characteristics of inertia gravity waves in the upper troposphere/lower stratosphere using a 205 MHz wind profiling radar

2017 ◽  
Vol 9 (3) ◽  
pp. 284-293 ◽  
Author(s):  
Ajil Kottayil ◽  
Karathazhiyath Satheesan ◽  
Kesavapillai Mohankumar ◽  
Sivan Chandran ◽  
Titu Samson
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Upper Troposphere ◽  
Inertia Gravity Waves

scholarly journals Internal Inertia–Gravity Waves in the Tropical Lower Stratosphere Observed by the Arecibo Radar

1984 ◽  
Vol 41 (15) ◽  
pp. 2359-2367 ◽  
Author(s):  
Yasuyuki Maekawa ◽  
Shoichiro Fukao ◽  
Toru Sato ◽  
Susumu Kato ◽  
Ronald F. Woodman
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Internal Inertia ◽  
Inertia Gravity Waves

scholarly journals A Study of Multiple Tropopause Structures Caused by Inertia–Gravity Waves in the Antarctic

2015 ◽  
Vol 72 (5) ◽  
pp. 2109-2130 ◽  
Author(s):  
Ryosuke Shibuya ◽  
Kaoru Sato ◽  
Yoshihiro Tomikawa ◽  
Masaki Tsutsumi ◽  
Toru Sato
Keyword(s):  
Gravity Waves ◽  
General Circulation ◽  
Climate Models ◽  
Lower Stratosphere ◽  
Circulation Model ◽  
Cold Bias ◽  
Syowa Station ◽  
Dynamical Mechanism ◽  
The Antarctic ◽  
Inertia Gravity Waves

Abstract Multiple tropopauses (MTs) defined by the World Meteorological Organization are frequently detected from autumn to spring at Syowa Station (69.0°S, 39.6°E). The dynamical mechanism of MT events was examined by observations of the first mesosphere–stratosphere–troposphere (MST) radar in the Antarctic, the Program of the Antarctic Syowa MST/Incoherent Scatter (IS) Radar (PANSY), and of radiosondes on 8–11 April 2013. The MT structure above the first tropopause is composed of strong temperature fluctuations. By a detailed analysis of observed three-dimensional wind and temperature fluctuation components, it is shown that the phase and amplitude relations between these components are consistent with the theoretical characteristics of linear inertia–gravity waves (IGWs). Numerical simulations were performed by using a nonhydrostatic model. The simulated MT structures and IGW parameters agree well with the observation. In the analysis using the numerical simulation data, it is seen that IGWs were generated around 65°S, 15°E and around 70°S, 15°E, propagated eastward, and reached the region above Syowa Station when the MT event was observed. These IGWs were likely radiated spontaneously from the upper-tropospheric flow around 65°S, 15°E and were forced by strong southerly surface winds over steep topography (70°S, 15°E). The MT occurrence is attributable to strong IGWs and the low mean static stability in the polar winter lower stratosphere. It is also shown that nonorographic gravity waves associated with the tropopause folding event contribute to 40% of the momentum fluxes, as shown by a gravity wave–resolving general circulation model in the lower stratosphere around 65°S. This result indicates that they are one of the key components for solving the cold-bias problem found in most climate models.

scholarly journals Identification of the sources of inertia-gravity waves in the Andes Cordillera region

2008 ◽  
Vol 26 (9) ◽  
pp. 2551-2568 ◽  
Author(s):  
A. Spiga ◽  
H. Teitelbaum ◽  
V. Zeitlin
Keyword(s):  
Gravity Waves ◽  
Mesoscale Model ◽  
Jet Stream ◽  
Earth Atmosphere ◽  
Jet Streams ◽  
The Andes ◽  
Wave Parameters ◽  
The Earth ◽  
Andes Cordillera ◽  
Inertia Gravity Waves

Abstract. Four major sources of inertia-gravity waves are known in the Earth atmosphere: upper-tropospheric jet-streams, lower-tropospheric fronts, convection and topography. The Andes Cordillera region is an area where all of these major sources are potentially present. By combining ECMWF and NCEP-NCAR reanalysis, satellite and radiosoundings data and mesoscale WRF simulations in the Andes Cordillera region, we were able to identify the cases where, respectively, the jet-stream source, the convective source and the topography source are predominantly in action. We retrieve emitted wave parameters for each case, compare them, and analyse possible emission mechanisms. The WRF mesoscale model shows very good performance in reproducing the inertia-gravity waves identified in the data analysis, and assessing their likely sources.

scholarly journals Observations and Numerical Simulations of Inertia–Gravity Waves and Shearing Instabilities in the Vicinity of a Jet Stream

2004 ◽  
Vol 61 (22) ◽  
pp. 2692-2706 ◽  
Author(s):  
Todd P. Lane ◽  
James D. Doyle ◽  
Riwal Plougonven ◽  
Melvyn A. Shapiro ◽  
Robert D. Sharman
Keyword(s):  
Numerical Simulations ◽  
Gravity Waves ◽  
Jet Stream ◽  
Sheared Flow ◽  
Mesoscale Structure ◽  
Air Turbulence ◽  
Research Aircraft ◽  
Wave Development ◽  
Upper Level ◽  
Inertia Gravity Waves

Abstract The characteristics and dynamics of inertia–gravity waves generated in the vicinity of an intense jet stream/ upper-level frontal system on 18 February 2001 are investigated using observations from the NOAA Gulfstream-IV research aircraft and numerical simulations. Aircraft dropsonde observations and numerical simulations elucidate the detailed mesoscale structure of this system, including its associated inertia–gravity waves and clear-air turbulence. Results from a multiply nested numerical model show inertia–gravity wave development above the developing jet/front system. These inertia–gravity waves propagate through the highly sheared flow above the jet stream, perturb the background wind shear and stability, and create bands of reduced and increased Richardson numbers. These bands of reduced Richardson numbers are regions of likely Kelvin–Helmholtz instability and a possible source of the clear-air turbulence that was observed.

Characterization of inertia gravity waves and associated dynamics in the lower stratosphere over the Indian Antarctic station, Bharati (69.4°S, 76.2°E) during austral summers

2019 ◽  
Vol 53 (5-6) ◽  
pp. 2887-2903 ◽  
Author(s):  
N. Koushik ◽  
Karanam Kishore Kumar ◽  
K. V. Subrahmanyam ◽  
Geetha Ramkumar ◽  
I. A. Girach ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Inertia Gravity Waves

scholarly journals Investigation of inertia-gravity waves in the upper troposphere/lower stratosphere over northern Germany observed with collocated VHF/UHF radars

2004 ◽  
Vol 4 (4) ◽  
pp. 4339-4381 ◽  
Author(s):  
A. Serafimovich ◽  
P. Hoffmann ◽  
D. Peters ◽  
V. Lehmann
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Wave Parameter ◽  
Data Sets ◽  
Northern Germany ◽  
Vhf Radar ◽  
Upper Troposphere ◽  
Rossby Wave Breaking ◽  
Uhf Wind Profiler ◽  
Inertia Gravity Waves

Abstract. A case study to investigate the properties of inertia-gravity waves in the upper troposphere/lower stratosphere has been carried out over Northern Germany during the occurrence of an upper tropospheric jet in connection with a poleward Rossby wave breaking event from 17-19 December 1999. The investigations are based on continuous radar measurements with the OSWIN VHF radar at Kühlungsborn (54.1° N, 11.8° E) and the 482 MHz UHF wind profiler at Lindenberg (52.2° N, 14.1° E). Both radars are separated by about 265 km. Based on wavelet transformations of both data sets, the dominant vertical wavelengths of about 2–4 km for fixed times as well as the dominant observed periods of about 11 h for the altitude range between 5 and 8 km are comparable. Gravity wave parameter have been estimated at both locations separately and by a complex cross-spectral analysis of the data of both radars. The results show the appearance of dominating inertia-gravity waves with characteristic horizontal wavelengths between 600 and 300 km moving in the opposite direction than the mean background wind and a secondary less pronounced wave with a horizontal wavelength in the order of about 200 km moving with the wind. Temporal and spatial differences of the observed waves are discussed.

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