Stratospheric Horizontal Wavenumber Spectra of Winds, Potential Temperature, and Atmospheric Tracers Observed by High-Altitude Aircraft

• Main Authors: Bacmeister, Julio T., Eckermann, Stephen D., Newman, Paul A., Lait, Leslie, Chan, K. R., Loewenstein, Max, Proffitt, Michael H., Gary, Bruce L.
• Other Authors: NAVAL RESEARCH LAB WASHINGTON DC E O HULBURT CENTER FOR SPACE RESEARCH
• Format: Text
• Language: English
• Published: 1996
• Subjects: Atmospheric Physics; Fluid Mechanics; *WIND; *GRAVITY WAVES; *TEMPERATURE; TURBULENCE; PRESSURE; WAVELET TRANSFORMS; FAST FOURIER TRANSFORMS; STRATIFICATION; OZONE; STRATOSPHERE; ATMOSPHERICS; INTERACTIONS; AIRCRAFT; REPRINTS; WIND VELOCITY; HORIZONTAL WAVENUMBER SPECTRA OF WINDS; LUMLEY SHUR WEINSTOCK BUOYANT SUBRANGE OF TURBULENCE; NONLINEAR GRAVITY WAVES; GRAVITY WAVE AIR PARCEL DISPLACEMENTS; TRACE GAS MIXING RATIO FIELDS; LAMINAR STRUCTURES; FILAMENTARY STRUCTURES; ENSTROPY CASCADING TWO DIMENSIONAL TURBULENCE; AASE II(SECOND ARCTIC AIRBORNE STRATOSPHERIC EXPEDITION); SPADE(STRATOSPHERIC PHOTOCHEMISTRY AEROSOL AND DYNAMICS EXPERIMENT); ASHOE(AIRBORNE SOUTHERN HEMISPHERE OZONE EXPERIMENT); MAESA(MEASUREMENTS FOR ASSESSING THE EFFECTS OF STRATOSPHERIC AIRCRAFT); ASHOE/MAESA; DWT(DISCRETE WAVELET TRANSFORMS); POWER SPECTRAL DENSITIES; BRUNT VAISALA FREQUENCIES; TAYLORS HYPOTHESIS; AIRCRAFT SPECTRA; ATMOSPHERIC TRACERS; Arctic
• Online Access: http://www.dtic.mil/docs/citations/ADA530959; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA530959

Horizontal wavenumber power spectra of vertical and horizontal wind velocities, potential temperatures, and ozone and N(2)O mixing ratios, as measured in the mid-stratosphere during 73 ER-2 flights (altitude approx. 20km) are presented. The velocity and potential temperature spectra in the 100 to 1-km wavelength range deviate significantly from the uniform -5/3 power law expected for the inverse energy-cascade regime of two-dimensional turbulence and also for inertial-range, three-dimensional turbulence. Instead, steeper spectra approximately consistent with a -3 power law are observed at horizontal scales smaller than 3 km for all velocity components as well as potential temperature. Shallower spectra are observed at scales longer than 6 km. For horizontal velocity and potential temperature the spectral indices at longer scales are between -1.5 and -2.0. For vertical velocity the spectrum at longer scales become flat. It is argued that the observed velocity and potential temperature spectra are consistent with gravity waves. At smaller scales, the shapes are also superficially consistent with a Lumley-Shur-Weinstock buoyant subrange of turbulence and/or nonlinear gravity waves. Contemporaneous spectra of ozone and N(sub 2)O mixing ratio in the 100 to 1-km wavelength range do conform to an approximately uniform -5/3 power law. It is argued that this may reflect interactions between gravity wave air-parcel displacements and laminar or filamentary structures in the trace gas mixing ratio field produced by enstropy-cascading two-dimensional turbulence. Published in the Journal of Geophysical Research, v101 nD5 p9441-9470, 27 Apr 1996. Paper number 95JD03835.