Horizontal variability of temperature, specific humidity, and cloud liquid water as derived from spaceborne observations

In an effort to assess the information content of spaceborne data wavenumber spectra of temperature, moisture and cloud liquid water are calculated from high-resolution infrared sounder (HIRS), as archived in the International Satellite Cloud Climatology Project - TIROS-N operational vertical sounder (ISCCP-TOVS) data set and special sensor microwave/imager (SSM/I) observations. The region under consideration is the southern hemispheric storm track, defined as the region extending from 38° to 58°S. The observational period is July 1989. In general, we find that the ISCCP-TOVS temperature spectrum has two distinct regimes, one where it follows a m−3, and one where it follows m−5/3 power law. These results are consistent with theoretical results for enstrophy and inverse energy cascade respectively in two-dimensional turbulence. The ISCCP-TOVS specific humidity spectra are more difficult to interpret. There is some indication that especially for layers near the surface, these spectra has two regimes similar to the tempererature spectra, but this is not unambiguous. For layers in the upper troposphere or lower stratosphere, the m−3 regime is not visible. The spatial variance and the shape of the columnar water vapor spectrum derived from these two sources are very similar. Some differences exists, at high wavenumber domain, but this could be the result of the employed method to construct the SSM/I daily mean distribution. Finally, there is some indication that the cloud liquid water spectrum follows the theoretical spectrum for the diffusion of a passive admixture in two-dimensional turbulence.

[1]  Chris Koen,et al.  Significance testing of periodogram ordinates , 1990 .

[2]  Steve Smith,et al.  Evidence for a Saturated Spectrum of Atmospheric Gravity Waves. , 1987 .

[3]  C. Leith.  Diffusion Approximation for Two‐Dimensional Turbulence , 1968 .

[4]  G. Manney,et al.  Wave number spectra from temperature‐humidity infrared radiometer 6.7‐μm water vapor data , 1990 .

[5]  Chester S. Gardner,et al.  Gravity wave models for the horizontal wave number spectra of atmospheric velocity and density fluctuations , 1993 .

[6]  Darren L. Jackson,et al.  A physical retrieval of cloud liquid water over the global oceans using special sensor microwave/imager (SSM/I) observations , 1993 .

[7]  P. Waldteufel,et al.  The Dynamics of Polar Jet Streams as Depicted by the METEOSAT WV Channel Radiance Field , 1981 .

[8]  R. Kraichnan.  Inertial Ranges in Two‐Dimensional Turbulence , 1967 .

[9]  G. D. Nastrom,et al.  Theoretical Interpretation of Atmospheric Wavenumber Spectra of Wind and Temperature Observed by Commercial Aircraft During GASP , 1986 .

[10]  D. Lilly.  Two-dimensional turbulence generated by energy sources at two scales , 1989 .

[11]  Douglas K. Lilly,et al.  Stratified Turbulence and the Mesoscale Variability of the Atmosphere , 1983 .

[12]  K. S. Gage,et al.  Evidence far a k−5/3 Law Inertial Range in Mesoscale Two-Dimensional Turbulence , 1979 .

[13]  William L. Smith,et al.  The Use of Eigenvectors of Statistical Covariance Matrices for Interpreting Satellite Sounding Radiometer Observations , 1976 .

[14]  Ronald N. Bracewell,et al.  The Fourier Transform and Its Applications , 1966 .

[15]  N. Lomb.  Least-squares frequency analysis of unequally spaced data , 1976 .

[16]  T. V. Zandt.  Spectral description of the gravity wave field , 1990 .

[17]  W. Rossow,et al.  The International Satellite Cloud Climatology Project (ISCCP): The First Project of the World Climate Research Programme , 1983 .

[18]  G. D. Nastrom,et al.  Spectrum of atmospheric vertical displacements and spectrum of conservative scalar passive additives due to quasi‐horizontal atmospheric motions , 1986 .

[19]  G. D. Nastrom,et al.  Horizontal spectra of atmospheric tracers measured during the Global Atmospheric Sampling Program , 1986 .

[20]  S. Baliunas,et al.  A Prescription for period analysis of unevenly sampled time series , 1986 .

[21]  G. D. Nastrom,et al.  A Climatology of Atmospheric Wavenumber Spectra of Wind and Temperature Observed by Commercial Aircraft , 1985 .

[22]  J. Scargle.  Studies in astronomical time series analysis. II - Statistical aspects of spectral analysis of unevenly spaced data , 1982 .

[23]  H. Tennekes.  Turbulent Flow In Two and Three Dimensions. , 1978 .

[24]  K. Trenberth,et al.  Implications of global atmospheric spatial spectra for processing and displaying data , 1993 .

[25]  Marcel Lesieur,et al.  Diffusion of a passive scalar in two-dimensional turbulence , 1985, Journal of Fluid Mechanics.

[26]  E. Groth.  Probability distributions related to power spectra. , 1975 .

[27]  D. Lilly,et al.  Mesoscale Variability of the Atmosphere , 1983 .

[28]  Darren L. Jackson,et al.  A comparison of SSM/I and TOVS column water vapor data over the global oceans , 1994 .