期刊文献+
共找到1篇文章
< 1 >
每页显示 20 50 100
A Special MJO Event with a Double Kelvin Wave Structure
1
作者 Lili ZHU Tim LI 《Journal of Meteorological Research》 SCIE CSCD 2017年第2期295-308,共14页
The second Madden–Julian Oscillation(MJO)event during the field campaign of the Dynamics of the MJO/Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011(DYNAMO/CINDY2011)exhibi ted an... The second Madden–Julian Oscillation(MJO)event during the field campaign of the Dynamics of the MJO/Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011(DYNAMO/CINDY2011)exhibi ted an unusual double rainband structure.Using a wavenumber-frequency spectral filtering method,we unveil that this double rainband structure arises primarily from the Kelvin wave component.The zonal phase speed of the double rainbands is about 7.9 degree per day in the equatorial Indian Ocean,being in the range of convectively coupled Kelvin wave phase speeds.The convection and circulation anomalies associated with the Kelvin wave component are characterized by two anomalous convective cells,with low-level westerly(easterly)and high(low)pressure anomalies to the west(east)of the convective centers,and opposite wind and pressure anomalies in the upper troposphere.Such a zonal wind–pressure phase relationship is consistent with the equatorial free-wave dynamics.While the freeatmospheric circulation was dominated by the first baroclinic mode vertical structure,moisture and vertical motion in the boundary layer led the convection.The convection and circulation structures derived based on the conventional MJO filter show a different characteristic.For example,the phase speed is slower(about 5.9 degree per day),and there were no double convective branches.This suggests that MJO generally involves multi-scales and it is incomplete to extract its signals by using the conventional filtering technique. 展开更多
关键词 Madden–Julian Oscillation(MJO) double Kelvin wave structure Wheeler–Kiladis spacetime spectra evolution characteristics
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部