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Dynamic and Regression Modeling of Ocean Variability in the Tide-Gauge Record at Seasonal and Longer PeriodsComparison of monthly mean tide-gauge time series to corresponding model time series based on a static inverted barometer (IB) for pressure-driven fluctuations and a ocean general circulation model (OM) reveals that the combined model successfully reproduces seasonal and interannual changes in relative sea level at many stations. Removal of the OM and IB from the tide-gauge record produces residual time series with a mean global variance reduction of 53%. The OM is mis-scaled for certain regions, and 68% of the residual time series contain a significant seasonal variability after removal of the OM and IB from the tide-gauge data. Including OM admittance parameters and seasonal coefficients in a regression model for each station, with IB also removed, produces residual time series with mean global variance reduction of 71%. Examination of the regional improvement in variance caused by scaling the OM, including seasonal terms, or both, indicates weakness in the model at predicting sea-level variation for constricted ocean regions. The model is particularly effective at reproducing sea-level variation for stations in North America, Europe, and Japan. The RMS residual for many stations in these areas is 25-35 mm. The production of "cleaner" tide-gauge time series, with oceanographic variability removed, is important for future analysis of nonsecular and regionally differing sea-level variations. Understanding the ocean model's strengths and weaknesses will allow for future improvements of the model.
Document ID
20080034471
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Hill, Emma M.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Ponte, Rui M.
(Atmospheric and Environmental Research, Inc. Lexington, MA, United States)
Davis, James L.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
August 24, 2013
Publication Date
May 1, 2007
Publication Information
Publication: Journal of Geophysical Research
Volume: 112
Subject Category
Oceanography
Funding Number(s)
CONTRACT_GRANT: NNG04GF09G
Distribution Limits
Public
Copyright
Other
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