A non-hydrostatic and compressible 2-D model simulation of Internal Gravity Waves generated by convection

• Goya Kenshi

  Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University

• Miyahara Saburo

  Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University

Bibliographic Information

Other Title

• non-hydrostatic and compressible 2-D model simulation of Internal Gravity Waves generated by convection

Abstract

Generation of internal gravitywaves (IGWs) by tropospheric convections and vertical propagation of the generated IGWs throughout the middle atmosphere are simulated by a non-hydrostatic compressible nonlinear two-dimensional numerical model. The present simulation demonstrates that (i) IGWs are generated by the tropospheric dry convections, (ii) zonal mean wind is decelerated by critical layer absorption of the generated IGWs in the upper tropospheric shear zone, (iii) secondary IGWs are radiated by the critical layer instability, and (iv) the secondary IGWs break down and accelerate zonal mean winds in the upper middle atmosphere. The detailed analyses show that (1) eastward propagating IGWs generated by the convection in tropospheric westerly with small wavelength of the order of 10 km and short period of the order of 10 min are dominant. It is found that the dominant waves are selected by a filtering effects of the prescribed westerly. (2) Several secondary IGWs with smaller horizontal wavelength than the primary IGW are radiated. The secondary IGWs propagate vertically in the form of wavepackets and break in the upper middle atmosphere due to local convective instability because of the exponential growth of the wave amplitudes with height. In the breaking region, the observed and theoretically predicted universal power law of the wind fluctuation, which states the m-3 dependence for the power spectra versus the vertical wavenumber m due to the wave saturation and breakdown, is also realized in the present model simulation.

Journal

• Earth, Planets and Space

  Earth, Planets and Space 51 (7-8), 485-498, 1999

  Society of Geomagnetism and Earth, Planetary and Space Sciences, The Seismological Society of Japan, The Volcanological Society of Japan , The Geodetic Society of Japan , The Japanese Society for Planetary Sciences

Keywords

• Space and Planetary Science
• Geology

Details

• CRID: 1390001206510484480
• NII Article ID: 10002697149
• NII Article ID: 130003956005
• NII Book ID: AA11211921
• DOI: 10.1186/bf03353210
• ISSN: 18805981
• ISSN: 13438832
• NDL BIB ID: 4863897
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4863897
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03353210.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03353210/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03353210
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed