Causes : regional scale
OBSERVATIONS CAUSES:GLOBAL SCALE CAUSES: REGIONAL SCALE DATA AND MAPS
The geographical distribution of thermal expansion trends for 1993-2003 correlates with regional sea level trends observed by Topex/Poseidon (Figure 1). This indicates that while other phenomena contribute to regional variations in sea level (atmospheric pressure variations, wind stress, etc.), the steric effect is dominant and responsible for the spatial patterns detected by satellite altimetry. |
EOF (Empirical Orthogonal Functions) analyses of the thermal expansion grids over the 1950-2000 period demonstrate that the steric variations in sea level are dominated by interannual/decadal oscillations associated with the main climate perturbations of the ocean-atmosphere coupled system (ENSO, PDO and NAO phenomena) (Figure 2: thermal expansion varies in space and time in response to these climate fluctuations). |
Figure 1: Comparison of sea level trends for 1993-2003, by Topex/Poseidon (right) and thermal expansion according to temperature and salinity data from the CLS Armor database (left) |
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Figure 2 : EOF 1 of thermal expansion for 1950-1998. Upper panel: spatial patterns |
Figure 3 : Geographical distribution of thermal expansion for 1955-2003 - according to Ishii et al. temperature data
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