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Bottom‐pressure signature of annual baroclinic R ossby waves in the northeast tropical P acific O cean
Author(s) -
Piecuch Christopher G.
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010667
Subject(s) - baroclinity , rossby wave , climatology , altimeter , geology , latitude , middle latitudes , sea level , annual cycle , oceanography , atmospheric sciences , geodesy
The annual cycle in bottom pressure ( p b ) in the northeast tropical Pacific Ocean (NTPO) is studied. Focus is on a zonal section along 12°N between 105°W and 145°W that is characterized by a strong annual cycle in sea level from satellite altimetry. Estimates of p b from the Gravity Recovery and Climate Experiment (GRACE), a state estimate produced by the Estimating the Circulation and Climate of the Ocean (ECCO) consortium, and a linear Rossby wave model (LRWM) are used. The GRACE NTPO p b annual cycle shows amplitudes as large as 1 cm water equivalent. The GRACE data also evidence westward propagation that is consistent with the behavior of long mode‐1 Rossby waves at this latitude, with phase increasing from east to west at a rate of ∼0.34 m s −1 . The ECCO and LRWM p b estimates corroborate the notion that GRACE reveals the p b signature of annual Rossby waves driven by interior wind stress curl and possibly damped by frictional processes. Results have implications for attempts to constrain global ocean mass using a single point mooring.