Variations of observed correlations between satellite altimetry and tide gauge data along the U.S. east coast

Yongcun Cheng (Center for Coastal Physical Oceanography, Old Dominion University, United States)

CoAuthors

Plag Hans-Peter (Mitigation and Adaptation Research Institute, Old Dominion University, United States); Ezer Tal (Center for Coastal Physical Oceanography, Old Dominion University, United States); Benjamin D. Hamlington (Center for Coastal Physical Oceanography, Old Dominion University, United States)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: The Geoid, Mean Sea Surfaces and Mean Dynamic Topography

Presentation type: Type Oral

Understanding the regional sea level variability is significant for coastal planning and implementing local sea level change adaptation and mitigation. The accelerated sea level rise has been detected between Cape Hatteras and Cape Cod at the U.S. east coast based on tide gauge data. Satellite altimeter provides accurate near global sea surface height data. Are there high correlations between low frequency tide gauge data and altimetry data over deep water regions in the North Atlantic? Do the correlations vary on decadal time scale?
In the present study, the CSEOF (cyclostationary empirical orthogonal function) method is used to remove the annual signal in tide gauge and satellite altimetry data (e.g., Absolute Dynamic topography from DUACS). Then the low frequency sea level variations are calculated from the EMD (empirical mode decomposition) analysis. Significant correlations and correlation variations between tide gauge data at the north of Cape Hatteras and altimeter data in the Northern and subtropical Atlantic Ocean are observed in the last two decades. The slowing down of Atlantic Meridional Overturning Circulation (AMOC) might be related with the phase reversal of correlations between composite tide gauge in the north of Cape Hatteras and satellite altimeter data in the subpolar Atlantic Ocean as well as strengthening of positive correlations in the subtropical regions of the mid-Atlantic Ocean. The sea level variations in the Labrador Sea are highly correlated to local sea level variations at the north of Cape Hatteras with phase leading of about 3 years. The spatial distribution characteristics of the correlation variations are linked to the variations of winter NAO, atmospheric forcing and Ocean Heat Content in the North Atlantic Ocean.
 

Oral presentation show times:

RoomStart DateEnd Date
Grand Ballroom 2 Wed, Oct 21 2015,17:30 Wed, Oct 21 2015,17:45
Yongcun Cheng
Center for Coastal Physical Oceanography, Old Dominion University
United States
y1cheng@odu.edu