Abstract
Transient and stationary spectra of kinetic energy (KE), available potential energy (APE) and enstrophy (EN), and their spectral fluxes as a function of the two-dimensional wavenumbern were computed for July 1979. Triangular truncation at zonal wavenumber 42 was used for computation. The slopes of various spectra in the wavenumber range 14≤n≤25 were obtained by fitting a straight line in log-log scale by the least square method. The transientKE, APE andEN spectra in the lower (upper) troposphere had slopes −2·21 (−2·30), −2·65 (−2·64) and −0·36 (−0·46), respectively. The effect of stationary and divergent motion on the slope values was investigated. The possible correlation between the slope and percentage of transient component in the combined energy and enstrophy was examined to identify the transient motion of the atmosphere with the two-dimensional homogeneous isotropic turbulence. The vertically averaged slope of kinetic energy and enstrophy in the lower (upper) troposphere was close to the value at 700 (200) hPa level.
The spectral fluxes of kinetic energy and enstrophy in the wavenumber range 14≤n≤25 satisfied, to a very rough approximation, the criteria of inertial subrange. The stationary fluxes were small. The estimated stationary-transient component of flux was larger, comparable and less than the corresponding transient flux of APE, KE and EN.
Representative levels for computation of energy and enstrophy spectra and their fluxes in the lower and upper troposphere were identified.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Baer F 1972 An alternate scale representation of atmospheric energy spectra;J. Atmos. Sci. 29 649–664
Baer F 1974 Hemispheric spectral statistics of available potential energy;J. Atmos. Sci. 31 932–941
Boer G J and Shepherd T G 1983 Large-scale two-dimensional turbulence in the atmosphere;J. Atmos. Sci. 40 164–184
Charney J G 1971 Geostrophic turbulence;J. Atmos. Sci. 28 1087–1095
Chen T C and Wiin-Nielsen A 1978 On nonlinear cascades of atmospheric energy and enstrophy in a two-dimensional spectral index;Tellus 30 313–322
Eliasen E B, Machenhauer B and Rasmussen E 1970 On a numerical method for integration of the hydrodynamical equations with a spectral representation of the horizontal fields;Rept No 2 Inst. Theor. Meteor. Copenhagen University 35
Fjortoft R 1953 On the changes in spectral distribution of kinetic energy for two-dimensional, nondivergent flow;Tellus 5 225–230
Gates W L 1961 Static stability measures in the atmosphere;J. Meteorol. 18 526–533
Kraichnan R H 1967 Inertial subranges in two-dimensional turbulence;Phys. Fluids 10 1417–1423
Lambert S J 1984 A global available potential energy-kinetic energy budget in terms of the two-dimensional wavenumber for the FGGE year;Atmosphere-Ocean 22 265–282
Leith C E 1968 Diffusion approximation for two-dimensional turbulence;Phys. Fluids 11 671–673
Leith C E 1971 Atmospheric predictability and two-dimensional turbulence;J. Atmos. Sci. 28 145–161
Lesieur M 1987Turbulence in fluids (eds) R J Moreau and G A Oravas, (The Netherlands: Martinus Nijhoff Publishers) pp. 187
Merilees P E 1979 On the kinematic properties of the—3 law for kinetic energy;Tellus 31 487–492
Robert A J 1966 The integration of a low order spectral form of the primitive meteorological equation;J. Meteorol. Soc. Jpn. 44 237–245
Shepherd T G 1987 A spectral view of nonlinear fluxes and stationary-transient interaction in the atmosphere;J. Atmos. Sci. 44 1166–1178
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Desai, S.S., Mishra, S.K. Global spectra of energy and enstrophy and their fluxes during July 1979. Proc. Indian Acad. Sci. (Earth Planet Sci.) 102, 329–350 (1993). https://doi.org/10.1007/BF02861507
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02861507