Studying Specific Features of the Propagation of Atmospheric Waves Generated by Tropospheric Sources and Variations in the Surface Pressure.

Autor: Kshevetskii, S. P., Kurdyaeva, Y. A., Kulichkov, S. N.
Předmět:
Zdroj: Izvestiya, Atmospheric & Oceanic Physics; Feb2022, Vol. 58 Issue 1, p30-43, 14p
Abstrakt: The generation and propagation of waves from model tropospheric meteorologic heat sources are theoretically studied. The processes of gas heating/cooling in water phase transitions at tropospheric altitudes are assumed to be the wave sources. In an analytical part of the study, equations are derived which describe the generation and propagation of acoustic and internal gravity waves separately. It is shown that powers of partial sources of acoustic and internal gravity waves always approximately coincide, regardless of wave frequencies, and the generation of internal gravity waves cannot occur without the generation of acoustic waves, and vice versa. Explicit analytical expressions are obtained for the generated waves. Due to resonant properties of the atmosphere, the high-frequency sources generate predominantly acoustic waves. The low-frequency sources generate mainly internal gravity waves if the sources work long enough for the resonance properties of atmosphere to be manifested. Using numerical experiments, the issue of error is investigated which is introduced if a tropospheric source is replaced with a surface one in which the pressure fluctuations on the surface are the recorded pressure fluctuations caused by the tropospheric source. It is shown that, if a tropospheric source operates at the infrasonic wave frequencies, then the wave patterns generated in the upper atmosphere from the tropospheric source and from the surface pressure fluctuations are almost identical. In the case of a tropospheric source operating at frequencies of internal gravity waves, the amplitude of waves from the surface pressure may be overestimated no more than twice. It is shown that, based on pressure fluctuations on the Earth's surface, some corrected surface pressure source can be constructed which takes into account the phase shifts of interfering waves that propagate into the upper atmosphere. This provides a significant improvement in the simulation of waves from meteorological sources based on data on atmospheric pressure fluctuations. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: