JpGU-AGU Joint Meeting 2020

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM12] 大気圏ー電離圏結合

コンビーナ:Huixin Liu(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、大塚 雄一(名古屋大学宇宙地球環境研究所)、Yue Deng(University of Texas at Arlington)、Loren Chang(Institute of Space Science, National Central University)

[PEM12-P10] Spatial and temporal distributions of atmospheric gravity wave potential energy evaluated using ERA-5 temperature data over the equatorial latitudes

*楊 時賢1Pan Chen-Jeih1Das Uma2林 千喬3 (1.國立中央大學、2.Department of Physics, Indian Institute of Information Technology, India、3.長榮大學)

キーワード:Atmospheric gravity waves、Potential energy、Zonal wind、Wave-mean flow interactions、ERA-5

In this study, we used the temperature profiles retrieved from ERA5, the newest atmospheric reanalysis dataset issued by the European Centre for Medium-Range Weather Forecasts (ECMWF), to evaluate the potential energy (EP) in the atmosphere from the near ground surface to ~80 km altitude over the equatorial latitudes of ±10°. EP is calculated from the fluctuation of temperature, which is considered to be generated by atmospheric gravity waves (AGWs), and we have constructed the spatial and temporal distributions of EP over the equatorial latitudes using the high-resolution data from ERA5. In this study, we will present the variations of EP in time, altitude, and longitude. Overall, EP is controlled by the zonal flow of the background atmosphere. Especially the time-varied descending structures of high EP value coincide with the westerly shear of zero-wind in the stratosphere, which implies the Kelvin wave-mean flow interactions in the stratospheric altitudes. Besides, the longitudinal analysis shows that EP is higher in the eastern Pacific at all altitudes except around the tropopause. In addition, we checked the EP values during different atmospheric and oceanic conditions, to examine the possible relationship between El Niño/La Niña and atmospheric gravity waves. With regards to the EP distribution caused by Kelvin waves in the stratosphere, we will also compare the results with the Kelvin wave amplitudes obtained by the two-dimensional fast Fourier transform (2D-FFT) method in this presentation.