HR: 0800h
AN: OS31A-0552    [Abstracts]
TI: The 1997-99 abrupt change of the upper ocean temperature in the northcentral Pacific
AU: * Kim, S
EM: sk@pacific.jpl.nasa.gov
AF: Jet Propulsion Lab/California Inst. Technology, 4800 Oak Grove Drive MS300-323, Pasadena, CA 91109 United States
AU: Lee, T
EM: tlee@pacific.jpl.nasa.gov
AF: Jet Propulsion Lab/California Inst. Technology, 4800 Oak Grove Drive MS300-323, Pasadena, CA 91109 United States
AU: Fukumori, I
EM: if@pacific.jpl.nasa.gov
AF: Jet Propulsion Lab/California Inst. Technology, 4800 Oak Grove Drive MS300-323, Pasadena, CA 91109 United States
AB: The abrupt warming of the northcentral Pacific Ocean from 1997 to 1999 is studied using an ocean data assimilation product. During this period, the average mixed-layer temperature in the region of 170-210E, 25-40N rises by 1.8K. The major contributors to the warming are surface heat flux (1.3K), geostrophic advection (0.7K) and entrainment (0.7K). For the geostrophic advection, the contributions by the zonal, meridional, and vertical components are 0.4, -0.1 and 0.3K, respectively. Mixing and meridional Ekman advection cool the domain. The significance of the geostrophic advection indicates the importance of ocean dynamics in controlling the abrupt warming tendency during the 1997-99 period and the inadequacy of a slab mixed-layer model in simulating such warming tendency. To the extent that this event reflects a phase switch of Pacific decadal variability, ocean dynamics cannot be ignored in studying such variability.
DE: 4215 Climate and interannual variability (3309)
DE: 4255 Numerical modeling
DE: 4572 Upper ocean processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting