Small-scale variability and model error in tropical Pacific sea level

LDEO Publication: 
Publication Type  Journal Article
Year of Publication  2004
Authors  Kaplan, A.; Cane, M. A.; Chen, D.; Witter, D. L.; Cheney, R. E.
Journal Title  Journal of Geophysical Research-Oceans
Volume  109
Issue  C2
Pages  -
Journal Date  Feb 4
ISBN Number  0148-0227
Accession Number  ISI:000189044800001
LDEO Publication Number  6493
Key Words  tropical sea level; small-scale variability; ocean modeling; data assimilation; nino southern-oscillation; data assimilation system; el-nino; ocean circulation; coupled model; topex/poseidon; initialization; prediction; resolution; topex

[1] Monthly interannual anomalies of tropical Pacific sea level height from TOPEX/ Poseidon altimetry are compared with simulation and assimilation products from a variety of models, ranging from a simple linear long wave approximation to ocean general circulation models. Major spatial similarities in the error patterns are identified. These include zonally elongated maxima in the northwest and southwest tropical Pacific Ocean, a band of high values near 10 degreesN, slightly inclined toward the equator from the Central American coast, and low values on the equator and in the southeastern tropical Pacific. These features are also present in the pattern of small-scale variability (SSV) of sea level height. Spatial and temporal components of this SSV are analyzed for predominant variability types. Monte Carlo experiments identify the areas where high SSV is wind-driven, caused by a similar pattern of variability in the wind stress. Model products systematically underestimate signal variance in such areas. Variability in other areas is due to the instability of ocean currents. The major component of uncertainty in the gridded satellite altimeter analyses is due to sampling error, for which estimates are developed and verified.


775MMTimes Cited:3Cited References Count:35

URL  <Go to ISI>://000189044800001
DOI  Doi 10.1029/2002jc001743