TY - JOUR
T1 - Upper ocean heat content and atmospheric anomaly fields in the off-equatorial North Pacific related to ENSO
AU - Hasegawa, Takuya
AU - Hanawa, Kimio
N1 - Funding Information:
The authors wish to express their sincere thanks to the members of the Physical Oceanography Laboratory, Tohoku University, and the Oceanographic Research Department at Meteorological Research Institute/Japan Meteorological Agency for their useful discussion. The manuscript was improved through the comments of the anonymous reviewers. The first author (TH) was financially supported by the Earth Science 21st Century COE program at Tohoku University and he is now supported by Research Fellowships of the Japan Society for the Promotion of Science (JSPS) for Young Scientists.
PY - 2007
Y1 - 2007
N2 - We have investigated interannual-scale variations of oceanic and atmospheric anomaly fields, such as upper ocean heat content (OHC), sea surface temperature (SST), latent heat flux (LHF) through the sea surface, sea level pressure (SLP) and wind stress curl (WSC) in the tropical Pacific and their relationships to El Niño/Southern Oscillation (ENSO) events. The results reported here show that the OHC and SST anomalies are almost in phase and lead LHF anomalies in the western tropical Pacific (WTP) region, which are preferable to the generation of subsequent atmospheric anomalies in the WTP. We also describe linear relationships between the amplitudes of these variables in the WTP. In addition, the results show that the both WSC and LHF anomalies are in phase with the temporal trend of OHC anomalies in the WTP, and suggest a combined effect of the local WSC and LHF anomaly in the WTP and ENSO-related, off-equatorial, westward propagating OHC anomaly to generate a large OHC anomaly in the WTP. In contrast to the WTP, OHC and SST anomalies are not in phase to the east of the WTP. The results also indicate that OHC anomalies in the WTP have a potential effect on the generation of an equatorial OHC anomaly via both a reflection of waves at the western boundary and atmospheric variations, which force the enhancement of western equatorial OHC anomaly. Therefore, the WTP is a key region where ENSO events are significantly modulated, and OHC anomalies in the WTP play an important role in the subsequent ENSO event.
AB - We have investigated interannual-scale variations of oceanic and atmospheric anomaly fields, such as upper ocean heat content (OHC), sea surface temperature (SST), latent heat flux (LHF) through the sea surface, sea level pressure (SLP) and wind stress curl (WSC) in the tropical Pacific and their relationships to El Niño/Southern Oscillation (ENSO) events. The results reported here show that the OHC and SST anomalies are almost in phase and lead LHF anomalies in the western tropical Pacific (WTP) region, which are preferable to the generation of subsequent atmospheric anomalies in the WTP. We also describe linear relationships between the amplitudes of these variables in the WTP. In addition, the results show that the both WSC and LHF anomalies are in phase with the temporal trend of OHC anomalies in the WTP, and suggest a combined effect of the local WSC and LHF anomaly in the WTP and ENSO-related, off-equatorial, westward propagating OHC anomaly to generate a large OHC anomaly in the WTP. In contrast to the WTP, OHC and SST anomalies are not in phase to the east of the WTP. The results also indicate that OHC anomalies in the WTP have a potential effect on the generation of an equatorial OHC anomaly via both a reflection of waves at the western boundary and atmospheric variations, which force the enhancement of western equatorial OHC anomaly. Therefore, the WTP is a key region where ENSO events are significantly modulated, and OHC anomalies in the WTP play an important role in the subsequent ENSO event.
KW - ENSO
KW - Upper ocean heat content
KW - Western tropical Pacific
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U2 - 10.1007/s10872-007-0050-5
DO - 10.1007/s10872-007-0050-5
M3 - Article
AN - SCOPUS:35348999226
VL - 63
SP - 561
EP - 572
JO - Journal of Oceanography
JF - Journal of Oceanography
SN - 0916-8370
IS - 4
ER -