Open AccessEstimation of the sea level trend south of Japan by combining satellite altimeter data with in situ hydrographic data
Author(s) -
Uchida Hiroshi,
Imawaki Shiro
Publication year - 2008
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008jc004796
Subject(s) - altimeter , bathythermograph , argo , hydrography , sea level , tide gauge , geology , geodesy , climatology , sea surface height , dynamic height , ocean surface topography , environmental science , oceanography
The sea level trend from1992 to 2006 was estimated by combining satellite altimeter data with in situ hydrographic data along the TOPEX/POSEIDON and Jason‐1 subsatellite track south of Japan. The sea level trend estimates from the altimeter data were consistent with those from the coastal tide gauge data. The mean sea level trend along the hydrographic observation line was 4.2 ± 0.8 mm a –1 . By assuming that the sea level trend due to large‐scale deformation of ocean basins from glacial isostatic adjustment is –0.3 mm a –1 , the sea level trend by the ocean mass change was estimated to be 1.3 ± 0.4 mm a –1 , and the steric height trend was estimated to be 3.2 ± 0.9 mm a –1 (2.8 ± 0.9 mm a –1 between 0 and 1800 dbar plus 0.4 ± 0.2 mm a –1 between 1800 and 4500 dbar). Steric height estimated from the altimeter data agreed well with that estimated from the conductivity‐temperature‐depth profiler and expendable bathythermograph data. However, steric height estimated from the Argo float data over year 2004–2006 was significantly biased of about –10 mm on average with respect to that estimated from the altimeter data. A systematic pressure error of about –2 dbar in the Argo float profiles could account for this negative bias in steric height.