Abstract
The reaction to p e r t u r b a t i o n s at the b o t t om of a stably s t r a t i f i e d layer characterized by small periodical variations of the thermal s t a b i l i t y p a r a m e t e r and capped by a, less stable, semi-infinite layer has been studied. When resonance conditions for internal zero order waves (represented by solutions obtained neglecting the small periodical variations of the s t a b i l i t y p a r a m e t e r itself) t r a p p e d in t h e lower layer are satisfied, secondary waves, generated by the i n t e r a c t i o n of zero order waves and t h e small variations af t h e s t a b i l i t y p a r a m e t e r , t u r n out to be resonant too. Some information can then be obtained on the localization along the vertical of convective breaking (and turbulent patches) in the lower layer, t a k i n g into account t h e superposition of zero order and secondary waves. These results seem to be relevant for t h e comprehension of t h e dynamics of t h e atmospheric inversions as well as of the oceanic thermocline.
Highlights
The reaction of a non rotating stratified atmosphere to external perturbations is most commonly analyzed assuming the constancy of the stratification parameter along the vertical direction
Experimental data show how the thermal stability parameter pattern is characterized by variations on many length scales along the vertical direction in the atmosphere as well as in the ocean, in those zones characterized by strong mean thermal stratification (13)
The pattern of the thermal stratification parameters in the stable layers could be properly represented by a constant positive value plus a random function; this case has been analyzed theoretically by different author (2'1>5); and some results have been obtained suggesting the important role played by such random variations in the propagations of internal waves
Summary
SUMMARY. — Thereaction to perturbationsatthebottom of astablystratifiedlayercharacterizedbysmallperiodicalvariations of thethermal stability parameter and capped by a, less stable, semi-infinite layer has been studied. When resonance conditions for internal zero order waves (represented b y solutions obtainedneglectingthesmall periodical variations of t h e stability parameter itself) trapped in the lower layer are satisfied, secondary waves , generatedbytheinteraction of zero orderwavesandthesmallvaria tions af t h e stability parameter , turnout to be resonant too. Viene messo in evidenza il fatto che, quando le condizioni di risonanza per le onde interne di ordine zero (rappresentate dalle soluzioni ottenute trascurando le piccole variazioni periodiche del parametro di stabilità) intrappolate nello strato inferiore sono soddisfatte, le onde secondarie generate dalla interazione delle onde di ordine zero e le variazioni periodiche del parametro di stabilità, risultano essere anch'esse risonanti. Da questa analisi teorica è possibile ottenere informazioni sulla localizzazione (lungo la verticale) delle instabilità convettive (strati turbolenti) nello strato più basso.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
