Two Comments on the Surface Quasigeostrophic Model for the Atmospheric Energy Spectrum
2009 (English)In: Journal of Atmospheric Sciences, ISSN 0022-4928, E-ISSN 1520-0469, Vol. 66, no 4, 1069-1072 p.Article in journal (Refereed) Published
The horizontal wavenumber spectra of wind and temperature in the upper troposphere and lower stratosphere display a narrow k(-3) range at scales on the order of 1000 km and a broad k(-5/3) range at mesoscales on the order of 1 to 500 km. Recently, Tulloch and Smith suggested that a surface quasigeostrophic (SQG) turbulence model can explain the observed spectra. Here, it is first argued that the mesoscale spectra are not likely to be explained by any quasigeostrophic model because the Rossby number corresponding to the mesoscale dynamics is on the order of unity or larger. Then it is argued that the SQG model in particular cannot explain the observations because its mesoscale spectrum displays a k(-5/3) dependence only in a very thin layer just below the tropopause. The thickness of this layer can be estimated to be of the order of 10 m, whereas aircraft measurements are typically performed several hundred meters away from the tropopause.
Place, publisher, year, edition, pages
2009. Vol. 66, no 4, 1069-1072 p.
wave-number spectra, lower stratosphere, upper troposphere, turbulence, temperature, climatology
IdentifiersURN: urn:nbn:se:kth:diva-18373DOI: 10.1175/2008jas2972.1ISI: 000265639800018ScopusID: 2-s2.0-69849092287OAI: oai:DiVA.org:kth-18373DiVA: diva2:336419
QC 201005252010-08-052010-08-052011-01-12Bibliographically approved