HR: 16:45h
AN: G34A-04 INVITED     [Abstracts]
TI: Low Frequency Inverted Barometer Signals and the Sea Level Record
AU: * Ponte, R M
EM: ponte@aer.com
AF: Atmospheric and Environmental Research, Inc., 131 Hartwell Avenue, Lexington, MA 02421 United States
AB: A dynamical interpretation of sea level records requires knowledge of the inverted barometer signals (η^ib) associated with the ocean response to atmospheric pressure. Variability in η^ib is estimated over the global ocean for the period 1958-2000 using monthly sea level pressure fields from two different atmospheric reanalyses. Low frequency η^ib signals and linear trends based on the two reanalyses are in good agreement over most regions. Uncertainties in estimates of η^ib seem to be largest in the Southern Ocean, where atmospheric pressure values are less well determined. Seasonal and interannual slib ~variability have weak rms amplitudes in equatorial regions <1 cm but can reach values >7 cm at high latitudes. Joint analyses with the global tide gauge dataset reveal the importance of both seasonal and interannual η^ib signals as contributors to observed sea level variance in many locations. Correcting the data for η^ib effects can lead to changes in variance of 40% or more. Linear trends in η^ib are mostly negative at low and mid latitudes and can cause negative biases in tide gauge estimates of global mean sea level rise, which are comparable in magnitude to the effects of post-glacial rebound. Removal of η^ib variability can reduce formal trend uncertainties, particularly when analyzing relatively short (decadal) records such as those available from satellite altimetry.
DE: 1640 Remote sensing (1855)
DE: 4275 Remote sensing and electromagnetic processes (0689, 2487, 3285, 4455, 6934)
DE: 4556 Sea level: variations and mean (1222, 1225, 1641)
DE: 4594 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005