Interannual and Decadal Variability in Tropical Pacific Sea Level
AbstractA notable feature in the first 20-year satellite altimetry records is an anomalously fast sea level rise (SLR) in the western Pacific impacting island nations in this region. This observed trend is due to a combination of internal variability and external forcing. The dominant mode of dynamic sea level (DSL) variability in the tropical Pacific presents as an east-west see-saw pattern. To assess model skill in simulating this variability mode, we compare 38 Coupled Model Intercomparison Project Phase 5 (CMIP5) models with 23-year satellite data, 55-year reanalysis products, and 60–year sea level reconstruction. We find that models underestimate variance in the Pacific sea level see-saw, especially at decadal, and longer, time scales. The interannual underestimation is likely due to a relatively low variability in the tropical zonal wind stress. Decadal sea level variability may be influenced by additional factors, such as wind stress at higher latitudes, subtropical gyre position and strength, and eddy heat transport. The interannual variability of the Niño 3.4 index is better represented in CMIP5 models despite low tropical Pacific wind stress variability. However, as with sea level, variability in the Niño 3.4 index is underestimated on decadal time scales. Our results show that DSL should be considered, in addition to sea surface temperature (SST), when evaluating model performance in capturing Pacific variability, as it is directly related to heat content in the ocean column. View Full-Text
Share & Cite This Article
Peyser, C.E.; Yin, J. Interannual and Decadal Variability in Tropical Pacific Sea Level. Water 2017, 9, 402.
Peyser CE, Yin J. Interannual and Decadal Variability in Tropical Pacific Sea Level. Water. 2017; 9(6):402.Chicago/Turabian Style
Peyser, Cheryl E.; Yin, Jianjun. 2017. "Interannual and Decadal Variability in Tropical Pacific Sea Level." Water 9, no. 6: 402.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.