HR: 0830h
AN: A41B-03 [Abstracts]
TI: MJO-Related Oceanic Kelvin Waves and ENSO Cycle: A Study With NCEP Global Ocean Data Assimilation System
AU: Seo, K
EM: Kyong-Hwan.Seo@noaa.gov
AF: Climate Prediction Center, NCEP/NOAA, 5200 Auth Road, Room 605, Camp Springs, MD 20746 United States
AU: * Xue, Y
EM: yan.xue@noaa.gov
AF: Climate Prediction Center, NCEP/NOAA, 5200 Auth Road, Room 605, Camp Springs, MD 20746 United States
AB:
The surface wind anomalies associated with the Madden-Julian oscillation(MJO) appear to play a critical role during the onset and termination phases of ENSO. The characteristics of the MJO-related oceanic Kelvin waves have not been systematically
studied due to a lack of ocean reanalysis that resolves intraseasonal variability. This study uses the operational ocean
reanalysis for 1982-2003 produced by the state-of-art global ocean data assimilation system at NCEP to explore the
relationship between SST anomalies of ENSO and MJO-related oceanic Kelvin waves. The first four extended empirical orthogonal functions of the depth of 20° C isotherm are used to represent the dominant oceanic Kelvin waves. The wave activity is
measured by seasonal variance of oceanic Kelvin waves (SVKW) at 130° W. SVKW peaks are associated with the onset stage of
warm ENSO events since they occur during the transition period and tend to produce positive tendency in NINO3.4 and heat
content, and lead mature phases by 5-11 months. MJO-related oceanic Kelvin wave activity is also shown to impact the growth
and termination of warm events. The consistent relationships do not occur in cold events. A real time monitoring tool using
SVKW index is proposed to support the official ENSO forecast at NCEP.
DE: 1704 Atmospheric sciences
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly