TY - JOUR
T1 - Examination of the merged sea surface temperature using wavelet analysis
AU - Hosoda, Kohtaro
AU - Kawamura, Hiroshi
PY - 2004/1/1
Y1 - 2004/1/1
N2 - In the previous study, merged sea surface temperature (SST) dataset called "New Generation SST" has been produced from several infrared and microwave satellite SSTs through an objective mapping. Here we examine the merged SST by comparison with moored buoy SST at 1 m depth, which is treated as true sea surface temperature. Comparison between wavelet spectra of merged and buoy SSTs shows that the former have larger amplitudes than those of the latter, which is partly explained as an aliasing effect due to TRMM Microwave Imager (TMI) aboard Tropical Rainfall Measuring Mission (TRMM) sampling on merged products. Coherency between wavelet-decomposed merged and buoy SSTs has high values in autumn and low ones in winter to spring. In winter, phase differences between them are positive, meaning that wavelet components of merged SST lag those of buoy SST. Reasons for delay and low coherency are: (1) seasonal components of merged SSTs are strongly affected by a lack of infrared SSTs due to clouds in winter, and (2) small-scale oceanic features, undetectable by coarse-resolution microwave SSTs, are blurred by the merging process. Improvements of merging methodology are discussed with regard to present study results.
AB - In the previous study, merged sea surface temperature (SST) dataset called "New Generation SST" has been produced from several infrared and microwave satellite SSTs through an objective mapping. Here we examine the merged SST by comparison with moored buoy SST at 1 m depth, which is treated as true sea surface temperature. Comparison between wavelet spectra of merged and buoy SSTs shows that the former have larger amplitudes than those of the latter, which is partly explained as an aliasing effect due to TRMM Microwave Imager (TMI) aboard Tropical Rainfall Measuring Mission (TRMM) sampling on merged products. Coherency between wavelet-decomposed merged and buoy SSTs has high values in autumn and low ones in winter to spring. In winter, phase differences between them are positive, meaning that wavelet components of merged SST lag those of buoy SST. Reasons for delay and low coherency are: (1) seasonal components of merged SSTs are strongly affected by a lack of infrared SSTs due to clouds in winter, and (2) small-scale oceanic features, undetectable by coarse-resolution microwave SSTs, are blurred by the merging process. Improvements of merging methodology are discussed with regard to present study results.
KW - Kuroshio recirculation region
KW - Merged SST
KW - Satellite SST
KW - Wavelet analysis
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U2 - 10.1007/s10872-005-5777-2
DO - 10.1007/s10872-005-5777-2
M3 - Article
AN - SCOPUS:10044263317
VL - 60
SP - 843
EP - 852
JO - Journal of Oceanography
JF - Journal of Oceanography
SN - 0916-8370
IS - 5
ER -