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Global analysis of scintillation variance: Indication of gravity wave breaking in the polar winter upper stratosphere
Author(s) -
Sofieva V. F.,
Kyrölä E.,
Hassinen S.,
Backman L.,
Tamminen J.,
Seppälä A.,
Thölix L.,
Gurvich A. S.,
Kan V.,
Dalaudier F.,
Hauchecorne A.,
Bertaux J.L.,
Fussen D.,
Vanhellemont F.,
Fanton d' Andon O.,
Barrot G.,
Mangin A.,
Guirlet M.,
Fehr T.,
Snoeij P.,
Saavedra L.,
Koopman R.,
Fraisse R.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl028132
Subject(s) - stratosphere , scintillation , gravity wave , atmospheric sciences , physics , turbulence , jet stream , polar night , environmental science , gravitational wave , atmosphere (unit) , polar , jet (fluid) , meteorology , astrophysics , optics , astronomy , thermodynamics , detector
Stellar scintillations observed through the Earth atmosphere are caused by air density irregularities generated mainly by internal gravity waves and turbulence. We present global analysis of scintillation variance in two seasons of year 2003 based on GOMOS/Envisat fast photometer measurements. Scintillation variance can serve as a qualitative indicator of intensity of small‐scale processes in the stratosphere. Strong increase of scintillation variance at high latitudes in winter is observed. The maximum of scintillation variance can be associated with the polar night jet. The simplified spectral analysis has shown the transition of scintillation spectra toward small scales with altitude, which is probably related with turbulence appearing as a result of wave breaking. The breaking of gravity waves in the polar night jet seems to start in the upper stratosphere, a predicted, but not confirmed by observations before, feature. Weaker enhancements in tropics are also observed; they might be related to tropical convection.