TY - JOUR
T1 - Assessment of Northeastern Japan Tree-Ring Oxygen Isotopes for Reconstructing Early Summer Hydroclimate and Spring Arctic Oscillation
AU - Sakashita, Wataru
AU - Yokoyama, Yusuke
AU - Miyahara, Hiroko
AU - Aze, Takahiro
AU - Obrochta, Stephen P.
AU - Ohyama, Motonari
AU - Yonenobu, Hitoshi
N1 - Funding Information:
The authors are deeply grateful to Y. Ueno of Tokyo Institute of Technology for offering us with his laboratory space to measure the tree-ring cellulose δ18O. This study was funded by the Japan Society for the Promotion of Science (JSPS) KAKENHI program (grant JP15H05816, JP25287051, JP25247082, JP26247085, JP15KK0151, JP16K05571, JP26101002, JP16H03098, and JP17H04492) and the program for JSPS Research Fellows DC1 (JP12J10623). Our tree-ring cellulose δ18O data sets (NI01B, NI03C, and NI7A) can be obtained from Table S1.
Funding Information:
The authors are deeply grateful to Y. Ueno of Tokyo Institute of Technology for offering us with his laboratory space to measure the tree-ring cellulose δ18O. This study was funded by the Japan Society for the Promotion of Science (JSPS) KAKENHI program (grant JP15H05816, JP25287051, JP25247082, JP26247085, JP15KK0151, JP16K05571, JP26101002, JP16H03098, and JP17H04492) and the program for JSPS Research Fellows DC1 (JP12J10623). Our tree-ring cellulose δ18O data sets (NI01B, NI03C, and NI7A) can be obtained from Table S1.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/9
Y1 - 2018/9
N2 - The spring Arctic Oscillation (AO) significantly affects the subsequent summer rainfall in the East Asian summer monsoon (EASM) region, and analysis of meteorological data indicates this teleconnection strength varied on interdecadal timescales during the late 20th century. Tree-ring records may be able to extend the relatively short observational record, but the extent to which these proxy reconstructions correspond to AO variability has yet to be explored in this region. Therefore, we present new tree-ring cellulose oxygen isotope (δ18O) records from northeastern Japan (Akita, northern limit of EASM), spanning a.d. 1950 to 2003 which overlaps with the instrumental record. Tree-ring δ18O is used for reconstructing the past hydroclimate variability and allows us to consider whether tree-ring δ18O has the potential to clarify the longer-term interdecadal changes in the spring AO-EASM relationship. Measurements and analyses show that our tree-ring δ18O data sets have a significant negative correlation with May-June-July relative humidity, and the tree-ring δ18O in northeastern Japan also significantly correlates with the summer EASM index. Temporal comparisons between our record and observed monthly AO index indicate that reconstructed following early summer relative humidity significantly correlates to the previous March-April-May AO. This linkage changes on interdecadal timescales, and the linkage is relatively strong during early 1970s through early 1990s. Similar results are also obtained using a separate tree-ring δ18O record from a separate location about 200 km to the southeast, suggesting that tree-ring cellulose δ18O in northeastern Japan is indeed useful for better understanding the long-term teleconnection between the spring AO and EASM.
AB - The spring Arctic Oscillation (AO) significantly affects the subsequent summer rainfall in the East Asian summer monsoon (EASM) region, and analysis of meteorological data indicates this teleconnection strength varied on interdecadal timescales during the late 20th century. Tree-ring records may be able to extend the relatively short observational record, but the extent to which these proxy reconstructions correspond to AO variability has yet to be explored in this region. Therefore, we present new tree-ring cellulose oxygen isotope (δ18O) records from northeastern Japan (Akita, northern limit of EASM), spanning a.d. 1950 to 2003 which overlaps with the instrumental record. Tree-ring δ18O is used for reconstructing the past hydroclimate variability and allows us to consider whether tree-ring δ18O has the potential to clarify the longer-term interdecadal changes in the spring AO-EASM relationship. Measurements and analyses show that our tree-ring δ18O data sets have a significant negative correlation with May-June-July relative humidity, and the tree-ring δ18O in northeastern Japan also significantly correlates with the summer EASM index. Temporal comparisons between our record and observed monthly AO index indicate that reconstructed following early summer relative humidity significantly correlates to the previous March-April-May AO. This linkage changes on interdecadal timescales, and the linkage is relatively strong during early 1970s through early 1990s. Similar results are also obtained using a separate tree-ring δ18O record from a separate location about 200 km to the southeast, suggesting that tree-ring cellulose δ18O in northeastern Japan is indeed useful for better understanding the long-term teleconnection between the spring AO and EASM.
KW - Arctic Oscillation
KW - East Asian summer monsoon
KW - Northeastern Japan
KW - oxygen isotopes
KW - tree-ring
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U2 - 10.1029/2018GC007634
DO - 10.1029/2018GC007634
M3 - Article
AN - SCOPUS:85053890175
VL - 19
SP - 3520
EP - 3528
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
SN - 1525-2027
IS - 9
ER -