1993 Fiscal Year Final Research Report Summary
Study of frequency and vertical wavenumber spectra of wind velocity flucutations due to atmospheric gravity waves
| Project/Area Number |
04640425
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Space and upper atmospheric physics
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
TSUDA Toshitaka Kyoto University, Radio Atmospheric Science Center, Associate Professor, 超高層電波研究センター, 助教授 (30115886)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Takuji Kyoto University, Radio Atmospheric Science Center, Research Associate, 超高層電波研究センター, 助手 (40217857)
YAMAMOTO Mamoru Kyoto University, Radio Atmospheric Science Center, Research Associate, 超高層電波研究センター, 助手 (20210560)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | atmospheric gravity waves / middle atmosphere / MU radar / meteor wind radar / atmospheric turbulence / jet stream / cumulous convection / spectral analysis |
|---|
| Research Abstract |
We have reviewed in this study recent observational studies on gravity wave characteristics, focussing on their excitation, propagation aud dissipation proccsses. Since gravity waves are normally observed as superpositioning of many components with different frequencies and wavenumbers, we employed a spectral analysis of wind velocity and temperature fluctuations, obatined with an MST radar, rocketsonde and radiosondes. It has been found that a linear saturation theory of gravity waves sucessfully explained fundamental characteristics of gravity waves, such as height variations of energy and dominant wavelengths.
We also delineated latitudinal variations of gravity wave activity through comparative studies between the MU radar at Shigaraki (35ﾟN, 136ﾟE), MF radars at Adelaide (35ﾟS, 139ﾟE) and Saskatchewan (52ﾟN, 107ﾟW). Comparisons were further extended to equatorial regions, by including radiosnde measurements in East Jawa, Indonesia (7ﾟS, 113ﾟE).
|
