| タイトル | A preliminary theory of the origin of the 40-50 day oscillation |
| 著者（英） | Lau, K. M.; Peng, L. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 1986-07-01 |
| 言語 | eng |
| 内容記述 | A theory of the 40 to 50 day oscillation in the tropical atmosphere which encompasses predominantly eastward propagation along the equator, spatial scales of wavenumber 1 and 2, slow time scales (20 to 70 days), and strong amplitude modulation in associated large-scale convective activity as a function of geographical location, i.e., pronounced convection is confined to the Indian Ocean and western Pacific, is presented. An initial disturbance generated near the equator disperses away from the source region, eastward by Kelvin waves and westward by Rossby waves. When the eastward disturbance passes over warm water it is expected to amplify by CISK due to enhanced supply of moisture from the ocean surface. Over cold water, its amplitude is expected to reduce due to decreased moisture supply. The climatological sea surface temperature contrast between the Indian Ocean/western Pacific and the eastern Pacific sets the spatial scale of the wave and its modulation to low wavenumbers and confines pronounced convection to the warm sector. If the eastward propagating wave can maintain itself over dissipation one circuit around the globe, it has a good chance to continue the process indefinitely, provided it is rejunvenated over the warm water with enough energy to go around for the next cycle. |
| NASA分類 | GEOPHYSICS |
| レポートNO | 87N23044 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/233732 |
|
