摘要
利用逐日的向外长波辐射资料OLR和再分析资料ERA-Interim研究并揭示了2000—2001年发生的一次继发性MJO和一次原发性MJO的初始对流发生的物理过程。研究发现继发性MJO对流事件主要是由边界层低层异常的水平温度平流引发边界层低层异常的垂直上升运动造成的。在异常的垂直上升运动与异常的水平湿度平流共同作用下,加湿了边界层大气,导致了上干下湿的大气的不稳定条件,从而触发了MJO对流。而原发性MJO对流事件的发生主要是由三支低频的对流耦合的湿波在印度洋相遇,即一支向东移动的Kelvin波,一支向西移动的Rossby波,一支向东传播的MJO模态,这三支波动相遇,其各自携带的湿度振幅叠加导致了大尺度对流不稳定层结,形成了有利于向东传播的行星尺度的MJO模态的对流发展。
Observed outgoing longwave radiation （OLR） and ERA-Interim reanalysis data were analyzed to reveal the initiation processes associated with a successive and a primary MJO event during 2000 -2001. It was found that the initiation of the successive event was caused by anomalous ascending motion induced by low-level horizontal temperature advection. The anomalous ascending motion, together with horizontal moisture advection, moistened lower troposphere and led to an unstable stratification＇and triggered convection. The initiation of the primary MJO event, on the other hand, was caused by the accumulation of anomalous moisture associated with three low-frequency modes, a convectively coupled Kelvin wave （CCKW）, an westward-propagating equatorial Rossby wave （ER） and a weak planetary-scale MJO mode. It is the merging of the low-level specific humidity anomalies of the three modes that led to the rapid setup of large-scale eonvectively unstable stratification and favored the development of the eastward-propagating planetary-scale MJO mode.
出处
《热带气象学报》
CSCD
北大核心
2016年第6期841-854,共14页
Journal of Tropical Meteorology
基金
China National 973 project(2015CB453200)
China National project(41575070)
NSFC(41475084)
OLR(N00014-16-12260)
NRL(N00173-13-1-G902)
Jiangsu NSF Key Project(BK20150062)
Jiangsu Shuang-Chuang Team(R2014SCT001)
Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
China Special Fund for Meteorological Research in the Public Interest(GYHY201306028)
Colleges and Universities in Jiangsu Province Plans to Graduate Research and Innovation(CXLX13_486)
