TY - JOUR
T1 - Estimating the geostrophic velocity obtained by HF radar observations in the upstream area of the Kuroshio
AU - Tokeshi, Ryoko
AU - Ichikawa, Kaoru
AU - Fujii, Satoshi
AU - Sato, Kenji
AU - Kojima, Shoichiro
N1 - Funding Information:
The authors would like to thank Professor Shiro Imawaki for his invaluable comments. Discussions with Dr. Shinichiro Umatani and Dr. Yutaka Yoshikawa were especially useful in interpreting the results. The authors also appreciate helpful suggestions from anonymous reviewers. This work is part of a project called “Monitoring and prediction of marine and atmospheric environmental changes in the East Asia” of the Research Insti- tute for Applied Mechanics, Kyushu University. This paper is also partially sponsored by Hydrospheric Atmospheric Research Center, Nagoya University, as a part of collaborative research programs.
PY - 2007
Y1 - 2007
N2 - A method to extract geostrophic current in the daily mean HF radar data in the Kuroshio upstream region is established by comparison with geostrophic velocity determined from the along-track altimetry data. The estimated Ekman current in the HF velocity is 1.2% (1.5%) and 48° (38°)-clockwise rotated with respect to the daily mean wind in (outside) the Kuroshio. Furthermore, additional temporal smoothing is found necessary to remove residual ageostrophic currents such as the inertial oscillation. After removal of the ageostrophic components, the HF geostrophic velocity agrees well with that from the altimetry data with rms difference 0.14 (0.12) m/s in (outside) the Kuroshio.
AB - A method to extract geostrophic current in the daily mean HF radar data in the Kuroshio upstream region is established by comparison with geostrophic velocity determined from the along-track altimetry data. The estimated Ekman current in the HF velocity is 1.2% (1.5%) and 48° (38°)-clockwise rotated with respect to the daily mean wind in (outside) the Kuroshio. Furthermore, additional temporal smoothing is found necessary to remove residual ageostrophic currents such as the inertial oscillation. After removal of the ageostrophic components, the HF geostrophic velocity agrees well with that from the altimetry data with rms difference 0.14 (0.12) m/s in (outside) the Kuroshio.
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U2 - 10.1007/s10872-007-0062-1
DO - 10.1007/s10872-007-0062-1
M3 - Article
AN - SCOPUS:54949127516
SN - 0916-8370
VL - 63
SP - 711
EP - 720
JO - Journal of Oceanography
JF - Journal of Oceanography
IS - 4
ER -