Solar system

Abstract:

The study of baroclinic instability has its origins in attempts to explain the genesis of midlatitude synoptic storm systems. The authors provide an account of the fundamental material and unfamiliar aspects of the linear theory. Essential observational background is provided in section 2, and the mathematical basics are laid out in section 3. The review for the most part focuses on quasigeostrophic dynamics, considering only dry dynamics. Discussion is slanted towards the terrestrial atmosphere. Stability criteria are treated in section 4, and normal modes are discussed in section 5. Aspects of the linear initial value problem are taken up in section 6. Section 7 considers briefly the difficult subject of nonlinear equilibration. Finally, section 8, takes stock of where the subject stands and where it is going. (from Authors)

Abstract:

The study of baroclinic instability has its origins in attempts to explain the genesis of midlatitude synoptic storm systems. The authors provide an account of the fundamental material and unfamiliar aspects of the linear theory. Essential observational background is provided in section 2, and the mathematical basics are laid out in section 3. The review for the most part focuses on quasigeostrophic dynamics, considering only dry dynamics. Discussion is slanted towards the terrestrial atmosphere. Stability criteria are treated in section 4, and normal modes are discussed in section 5. Aspects of the linear initial value problem are taken up in section 6. Section 7 considers briefly the difficult subject of nonlinear equilibration. Finally, section 8, takes stock of where the subject stands and where it is going. (from Authors)

Abstract:

An analysis of thermal profiles and dynamics over a wide range of latitudes for the venusian atmosphere between 70 and 90 km is presented based on high spatial resolution infrared spectra of the night side obtained by the near infrared mapping spectrometer (NIMS) experiment during the Galileo-Venus encounter in February 1990. Using the 4.3-μm CO2 absorption band, the temperature profile is retrieved in the 75- to 91-km altitude region over a latitudinal range of -59· to + 64·. Compared to earlier observations from the Pioneer Venus mission, the temperature at 91 km is about 10 K higher and between 74 and 83 km about 3.6 K colder. An equator to pole warming at constant pressure levels is found and implications for the zonal wind profiles are drawn under the assumption that the atmosphere is in cyclostrophic balance in the region of 70 to 90 km. The results are in correspondence with direct wind measurements from ground-based observations at 95 km and 105 km altitude. © 1995 Academic Press, Inc.