Sea Level Swings in the Pacific—A Review

Y. Tony Song (JPL/NASA, United States)

CoAuthors

J.-H. Moon (JNU, Korea)

Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)

Session: Science II: Large Scale Ocean Circulation Variability and Change

Presentation type: Type Forum

Over the past decades, the sea level in the western Pacific rose up to three times faster than the global mean, while its counterpart in the eastern Pacific including U.S. west coast was nearly stationary or decreasing [Moon and Song, 2013]. In fact, the regional seal-level trends have undergone two shifts, during the mid-1970s and in the early 1990s, with an east-west dipole pattern in the tropical Pacific. In each of these phases, the regional sea levels accelerated on one side of the Pacific, but decelerated on the other side [Moon et al., 2013]. It is puzzling how long this pattern of regional sea level changes has been gone, what is the dynamic cause, and how these can affect deep ocean. These regional sea level changes, when superimposed on the global trend of sea level rise, could have profound implications for coastal communities and the health of marine and estuarial habitats. Combining recently reconstructed long-term sea level data products, upper-ocean measurements, recent satellite data, and a non-Boussinesq ocean circulation model [Song and Colberg, 2011], we will show that (1) the multi-decadal sea-level swings are the consequence of upper-ocean heat changes, closely related to the Pacific Decadal Oscillation (PDO)-induced ocean circulations; (2) the dueling climate cycles, PDO and ENSO, may have intensified the sea level swings in the tropical Pacific since 1980s [Moon et al., 2015]; and (3) differently, the deep ocean has shown a cooling trend in the tropics while a warming trend in the northern Pacific. Their underling dynamic mechanisms will be discussed.

Reference:
Moon, J.-H., Y. T. Song, and H. Lee (2015), PDO and ENSO modulations intensified decadal sea level variability in the tropical Pacific, J. Geophys. Res. Oceans, 120, doi:10.1002/2015JC011139.
Moon, J.-H., Y. T. Song, P. D. Bromirski, and A. J. Miller (2013), Multidecadal regional sea level shifts in the Pacific over 1958–2008, J. Geophys. Res. Oceans, 118, doi:10.1002/2013JC009297.
Moon, J.-H. and Y. T. Song (2013), Sea level and heat content changes in the western North Pacific. J. Geophys. Res. Oceans, 118, 2014-2022, doi:10.1002/jgrc.200.
Song, Y. T. and F. Colberg (2011), Deep ocean warming assessed from altimeters, Gravity Recovery and Climate Experiment, in situ measurements, and a non-Boussinesq ocean general circulation model, J. Geophys. Res., 116, C02020, doi:10.1029/2010JC006601.
 
Y. Tony Song
JPL/NASA
United States
Tony.Song@jpl.nasa.gov