研究者詳細 - 中塚　武

Tree-rings stable isotope (d(18)O and d(2)H) based 368 years long term precipitation reconstruction of South Eastern Kashmir Himalaya 査読有り国際共著

Pandey Uttam, Nakatsuka Takeshi, Mehrotra Nivedita, Zhen Li, Kato Yoshikazu, Sano Masaki, Shah Santosh K.

SCIENCE OF THE TOTAL ENVIRONMENT 892 巻頁： 164640 2023年9月

TWO NEW MILLENNIUM-LONG TREE-RING OXYGEN ISOTOPE CHRONOLOGIES (2349-1009 BCE AND 1412-466 BCE) FROM JAPAN 査読有り

Sano Masaki, Kimura Katsuhiko, Miyake Fusa, Tokanai Fuyuki, Nakatsuka Takeshi

RADIOCARBON 65 巻 ( 3 ) 頁： 721 - 732 2023年6月

Tree ring oxygen isotope dating of wood recovered from a canal in the ancient capital of Japan 査読有り

Sano Masaki, Li Zhen, Murakami Yumiko, Jinno Megumi, Ura Yoko, Kaneda Akihiro, Nakatsuka Takeshi

JOURNAL OF ARCHAEOLOGICAL SCIENCE-REPORTS 45 巻 2022年10月

樹木年輪セルロースの酸素同位体比からみた古代日本の気候変動招待有り査読有り

中塚武

国立歴史民俗博物館研究報告 232 巻頁： 11 - 30 2022年3月

年輪酸素同位体比を用いた弥生・古墳時代の気候・農業生産・人口の変動シミュレーション招待有り査読有り

中塚武

国立歴史民俗博物館研究報告 231 巻頁： 317 - 336 2022年2月

Tree-ring oxygen isotope across monsoon Asia: Common signal and local influence 査読有り

Xu Chenxi, Zhao Qingyu, An Wenling, Wang Simon, Tan Ning, Sano Masaki, Nakatsuka Takeshi, Borhara Krishna, Guo Zhengtang

QUATERNARY SCIENCE REVIEWS 269 巻 2021年10月

記述言語：英語出版者・発行元：Quaternary Science Reviews

Tree-ring cellulose oxygen isotope (δ18O) in monsoon Asia (MA) is affected collectively by local hydroclimate and remote oceanic-atmospheric variations. Variations of tree-ring δ18O have been widely used for quantitative reconstructions of monsoon-season precipitation, relative humidity and drought severity. However, local hydroclimate and remote large-scale circulation's influences on tree-ring δ18O has not been fully resolved. Here, we collected 24 tree-ring δ18O chronologies covering the period of 1884–1999 across a wide range of MA and investigated the common signals of these chronologies using principal component analysis. The first principal component (PC1) of the 24 tree-ring δ18O chronologies explained 25.2% of the total variances and showed significant positive correlations with the observed Asian summer monsoon oxygen isotope index (r = 0.69) during the period of 1978–1999, suggesting that a common signal of precipitation δ18O does exist in MA and that it is highly correlated with El Niño–Southern Oscillation (ENSO) (r = 0.72) and the South Asian summer monsoon precipitation (r = −0.66). South Asian summer monsoon precipitation and ENSO are the main factors controlling this common signal of tree-ring δ18O across MA. PC1 of tree-ring δ18O chronologies in MA also depicted a negative (positive) correlation with the Atlantic Multidecadal Oscillation (Pacific Decadal Oscillation), indicating the large-scale circulation influences. After removing the large-scale circulation influences on tree-ring δ18O chronologies, however, the residual tree-ring δ18O chronologies exhibit negative correlations with the regional hydroclimate, highlighting the role local hydroclimate on the individual tree-ring δ18O variations.

DOI： 10.1016/j.quascirev.2021.107156

Reconstruction of drought and long-rain chronologies since the 17th century in central Japan using intra-annual tree-ring oxygen isotope ratios and documentary records 査読有り

古気候学者から歴史学者への協働の呼びかけ―現代の諸問題に対峙するために－招待有り

中塚武

日本史研究 700 巻頁： 147 - 162 2020年12月

酸素同位体比年輪年代法－高精度編年への挑戦招待有り

中塚武

季刊考古学 150 巻頁： 142-145 2020年2月

年輪を用いた南アルプスにおける1774 年以降の夏期気温の復元査読有り

安江恒, 久保典子, 赤尾実紀子, 佐野雅規, 中塚武

地学雑誌 128 巻 ( 1 ) 頁： 49-59 2019年2月

Seasonal changes of δD and δ18O in tree-ring cellulose of Quercus crispula suggest a change in post-photosynthetic processes during earlywood growth. 査読有り国際共著国際誌

Nabeshima E, Nakatsuka T, Kagawa A, Hiura T, Funada R

Tree physiology 38 巻 ( 12 ) 頁： 1829 - 1840 2018年12月

A 180-year-long isotopic record of tree-ring cellulose on Okinawa Island, Japan. 査読有り国際誌

Ryu Uemura, Miki Uemura, Masaki Sano, Takeshi Nakatsuka

Geochemical Journal 52 巻頁： e21-e27 2018年11月

酸素同位体比年輪年代法による池島・福万寺遺跡の弥生時代水田に関する年代観の構築

井上智博, 中塚武, 李貞, 對馬あかね, 佐野雅規, 遠部慎, 中原計

大阪文化財研究 51 巻頁： 1-26 2018年3月

酸素同位体比年輪年代法の誕生と展開招待有り査読有り

中塚　武

考古学と自然科学 76 巻頁： 1-13 2018年3月

『CD-ROM版鎌倉遺文』に収録された古文書件数と気候復元データの関係の定量的分析招待有り査読有り

伊藤啓介, 中塚武

鎌倉遺文研究 40 巻頁： 23-53 2017年10月

Recent enhancement of central Pacific El Niño variability relative to last eight centuries. 査読有り国際共著国際誌

Liu Y, Cobb KM, Song H, Li Q, Li CY, Nakatsuka T, An Z, Zhou W, Cai Q, Li J, Leavitt SW, Sun C, Mei R, Shen CC, Chan MH, Sun J, Yan L, Lei Y, Ma Y, Li X, Chen D, Linderholm HW

Nature communications 8 巻頁： 15386 2017年5月

Tree-ring oxygen isotope cross-dating between southeastern China and central Japan 査読有り国際共著

Shi S., Shi J., Nakatsuka T., Sano M., Li Z., Shu J., Wang X., Huang J., Li J., Lu H.

Dendrochronologia 91 巻 2025年6月

Iizuka, H; Sho, K; Li, Z; Sano, M; Kato, Y; Nakatsuka, T

CLIMATE OF THE PAST 21 巻 ( 1 ) 頁： 133 - 144 2025年1月

Method to measure tree-ring width, density, elemental composition, and stable carbon and oxygen isotopes using one sample 査読有り国際共著

Xu, CX; Zhao, YR; An, WL; Zhao, QY; Liu, YC; Sano, M; Nakatsuka, T

JOURNAL OF FORESTRY RESEARCH 35 巻 ( 1 ) 2024年12月

Methodological constrains of tree-ring stable isotope chronologies 査読有り

Tito Arosio, Max Torbenson, Tatiana Bebchuk, Alexander Kirdyanov, Jan Esper, Takeshi Nakatsuka, Masaki Sano, Otmar Urban, Kurt Nicolussi, Markus Leuenberger, Ulf Büntgen

Quaternary Science Reviews 340 巻頁： 108861 2024年9月

A 1179-yr (417-1595 CE) tree-ring oxygen isotope chronology for northern Japan validated using the 774-775 CE radiocarbon spike 査読有り

Sano, M; Li, Z; Tsushima, A; Kimura, K; Nakamura, T; Ohyama, M; Sakamoto, M; Nakatsuka, T; Hakozaki, M

RADIOCARBON 2024年5月

Summer climate information recorded in tree-ring oxygen isotope chronologies from seven locations in the Republic of Korea 査読有り国際共著 Open Access

Choi, EB; Park, JH; Sano, M; Nakatsuka, T; Seo, JW

FRONTIERS IN FORESTS AND GLOBAL CHANGE 7 巻 2024年4月

学際研究・市民科学の国際連携に向けて招待有り査読有り

中塚武

日本の科学者 59 巻 ( 5 ) 頁： 32 - 37 2024年

京都府芦生研究林の広葉樹サワグルミの年層内同位体比変動による高分解能古気候復元の可能性

渡邊裕美子, 片山喜登, 李貞, 中塚武

日本地球化学会年会要旨集 71 巻 ( 0 ) 頁： 121 2024年

記述言語：日本語出版者・発行元：一般社団法人日本地球化学会

アジアモンスーン地域において、樹木年輪の年輪幅や同位体比などを用いて、過去の水文気候を復元する研究が盛んに行われている。そのなかでもセルロース酸素同位体比は異なる樹種であっても個体間相関が良く、降水量や相対湿度と有意な相関を示すため、優れた水文プロキシとされている。それらのほとんどは年層毎に同位体比を測定した研究であり、より高い時間分解能で降水情報をえるため、年層内同位体比に注目が集まっている。本研究では、広葉樹であるサワグルミの年層を6分割して同位体比分析し、気象観測データと精密に対比することにより、高時間分解能な水文プロキシとしての可能性を検証した

DOI： 10.14862/geochemproc.71.0_121

Intra-Annual Isotope Records from Japanese Cedar Tree Samples in Akita Prefecture

羅銘浩, 渡邊裕美子, Zhen Li, 中塚武

日本地球化学会年会要旨集 71 巻 ( 0 ) 頁： 120 2024年

記述言語：日本語出版者・発行元：一般社団法人日本地球化学会

Tree-ring width, density, and isotopic data can be used for paleoclimate reconstruction. Recently, due to the advantage of being less affected by tree physiological factors, the use of tree-ring cellulose isotope ratios in paleoclimate reconstruction has become a new research focus. Specifically, intra-annual isotope ratios have shown high-resolution potential for paleoclimate reconstruction, with feasibility demonstrated in multiple studies in central Japan. However, such high-resolution paleoclimate reconstruction studies in the relatively high-latitude region of northern Japan are still relatively scarce. Therefore, in this study, we collected tree-ring samples from northern Japan to explore whether the same reconstruction methods are applicable to this colder climate region.

DOI： 10.14862/geochemproc.71.0_120

Assessments of tree-ring intra-annual & delta;O-18 record for reconstructing hydroclimate with high temporal resolution 査読有り

RADIOCARBON DATING OF TREE RINGS FROM THE BEGINNING AND END OF THE YAYOI PERIOD, JAPAN 査読有り

Sakamoto Minoru, Hakozaki Masataka, Nakatsuka Takeshi, Ozaki Hiromasa

RADIOCARBON 2023年8月

Watanabe Yumiko, Katayama Yoshito, Li Zhen, Nakatsuka Takeshi, Tazuru Suyako

GEOSCIENCE LETTERS 10 巻 ( 1 ) 2023年6月

大湫神明神社および伊勢神宮のスギ巨木に含まれる硫黄同位体比の変遷

塩出晏弓, 谷川東子, 平野恭弘, 中塚武, 加藤義和, 石田卓也, 佐瀬裕之

日本森林学会大会発表データベース 134 巻 ( 0 ) 頁： 503 2023年5月

記述言語：英語掲載種別：研究論文（研究会，シンポジウム資料等）出版者・発行元：日本森林学会

イオウは産業革命以降、地球の循環量が2倍になった元素として、人間活動の影響を色濃く受けていることが指摘されている。イオウ酸化物が大気汚染の原因物質の１つとして各種生態系に降り注ぐと生態系がダメージを受けることも、数多くの研究が明らかにしている。樹木はイオウを根から、あるいは気孔から吸収する。これまで、樹木の年輪に含まれるイオウ濃度やイオウ安定同位体比の分析に基づき、過去のイオウ沈着量や発生源の変遷についての研究が行われているが、1本の樹木から得られる円盤試料で数百年を超える年輪を含む個体は非常に貴重なため、化石燃料が大量に使われるようになる以前の期間を含む長期的な分析の報告は見当たらない。本研究の目的は、中部日本の森林に影響を与えたイオウ源とイオウによる大気汚染を考察することである。この目的のため、2020年の豪雨時に倒壊した岐阜県瑞浪市大湫町の神明神社スギと、2009年の台風により倒壊した三重県伊勢市の伊勢神宮スギという2本の巨樹の年輪を5年ごとに分割し、湿式灰化法により酸分解し、1700年代以降のイオウ濃度とそのδ34S値を分析した。今回はイオウについて特に注目したい年代を8つ選びその結果を報告する。

DOI： 10.11519/jfsc.134.0_503

A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD FROM THAILAND: INVESTIGATING THE C-14 OFFSET INDUCED BY AIR MASS TRANSPORT FROM THE INDIAN OCEAN 査読有り国際共著

Sano Masaki, Pumijumnong Nathsuda, Fujita Koji, Hakozaki Masataka, Miyake Fusa, Nakatsuka Takeshi

RADIOCARBON 65 巻 ( 2 ) 頁： 505 - 519 2023年4月

Asian-Australian summer monsoons linkage to ENSO strengthened by global warming 査読有り国際共著

Xu Chenxi, Wang S. -Y. Simon, Borhara Krishna, Buckley Brendan, Tan Ning, Zhao Yaru, An Wenling, Sano Masaki, Nakatsuka Takeshi, Guo Zhengtang

NPJ CLIMATE AND ATMOSPHERIC SCIENCE 6 巻 ( 1 ) 2023年2月

The modulation of Pacific Decadal Oscillation on ENSO-East Asian summer monsoon relationship over the past half-millennium 査読有り国際共著

Hau Nguyen-Xuan, Sano Masaki, Nakatsuka Takeshi, Chen Shin-Hao, Chen I. -Ching

SCIENCE OF THE TOTAL ENVIRONMENT 857 巻 ( Pt 2 ) 頁： 159437 2023年1月

愛知県出土材の年輪幅に基づく中世ヒノキ標準年輪曲線（1087–1574 年）の構築．査読有り

佐野雅規・大石恭平・樋上　昇・中塚　武

文化財科学 86 巻頁： 37 - 38 2023年

樹木年輪酸素同位体比を用いた歴史資料の旱魃・長雨記録の客観化

飯塚比呂人, 庄建治朗, 李貞, 加藤義和, 中塚武

水文・水資源学会研究発表会要旨集 36 巻 ( 0 ) 頁： 17 2023年

記述言語：日本語出版者・発行元：水文・水資源学会

歴史上，旱魃・長雨は人々の生活に多大な影響を与え，数々の古文書記録に記されている．またこれらの記録から災害の周期性を検討した研究も行われている．しかしながら古文書記録は書き手の主観が混じった定性的なデータであることが多く，記述が断続的な期間も多い．またどのような気象現象が旱魃・長雨と判断されたかを客量的に評価する研究は進んでいない．そこで本研究では，岐阜県東濃地方を対象として，定量的な古気候代替データである樹木年輪酸素同位体比を用いて，歴史資料における旱魃や長雨の記録の客観的評価を試みた．　歴史資料として東濃地方の市史・町史等21点を収集した．また樹木年輪酸素同位体比は岐阜県瑞浪市大湫町のスギ(Cryptomeria japonica)から409年分を連続的に測定した．特に樹木年輪酸素同位体比は1年輪を主に6分割することで，数週間単位の時間分解能を得た．これらのデータを比較した結果，酸素同位体比が旱魃・長雨の影響を反映していたことや，当該年の前数年間と比較した梅雨の降水の過多が，旱魃・長雨の判断要因になっていた可能性が示された．このように本研究では，樹木年輪酸素同位体比の活用が，歴史資料の非連続性・非客観性を補完する際に有効な手段であることが示唆された．

DOI： 10.11520/jshwr.36.0_17

Different moisture regimes during the last 150 years inferred from a tree-ring δ18O network over the transitional zone of the Asian summer monsoon

Interdecadal to Multidecadal Variability of East Asian Summer Monsoon Over the Past Half Millennium 査読有り国際共著

Shi Feng, Goosse Hugues, Li Jianping, Yin Qiuzhen, Ljungqvist Fredrik Charpentier, Lian Tao, Sun Cheng, Wang Lin, Wu Zhiwei, Li Juan, Zhao Sen, Xu Chenxi, Liu Wei, Liu Ting, Nakatsuka Takeshi, Guo Zhengtang

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 127 巻 ( 20 ) 2022年10月

Different moisture regimes during the last 150 years inferred from a tree-ring delta O-18 network over the transitional zone of the Asian summer monsoon 査読有り国際共著

Fan Haowen, Gou Xiaohua, Nakatsuka Takeshi, Li Zhen, Fang Keyan, Su Jiajia, Gao Linlin, Liu Wenhuo

JOURNAL OF HYDROLOGY 613 巻 2022年10月

Fan H., Gou X., Nakatsuka T., Li Z., Fang K., Su J., Gao L., Liu W.

Journal of Hydrology 613 巻 2022年10月

出版者・発行元：Journal of Hydrology

The East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) are two interactive climate systems dominating the moisture variability of Monsoon Asia. However, ISM-EASM interactions and their effects on regional moisture dynamics remain unclear. This study investigated the spatiotemporal characteristics of monsoon-related hydroclimate variability by establishing a new tree-ring oxygen isotope ratio (δ18Otree) network of eight δ18Otree records covering the last 150 years in southern China, which differs from previous studies that used data from individual sites. The δ18Otree chronologies were found to be sensitive to regional hydroclimatic changes during the monsoon season. The δ18Otree network indicated an east–west clustering pattern in the ISM-EASM transitional zone, which demonstrates an asynchrony in δ18Otree variability in the west and east of this region. Regional variability of the west and east δ18Otree modes reflected the different moisture signals, as indicated by their significant correlations with modern observations and paleo-δ18O records in disparate upstream regions of moisture transport (the Indochina Peninsula and Southeast China). This finding was confirmed by the east–west distinct pattern of spatial isotopic depletion of monsoon rainfall that originates from coastal areas of tropical oceans (Bay of Bengal and South China Sea) to the study area, as well as the consistent present-day pattern of atmospheric vapor transport during the monsoon season. In addition, the west and east modes exhibited stronger associations with ISM variability, whereas the east–west δ18Otree gradient captured the EASM-related hydroclimatic signal, suggesting that summer moisture variability in the ISM-EASM transitional zone was regulated more by ISM than by EASM during the last 150 years. The relationships between δ18Otree and large-scale ocean–atmosphere interaction modes revealed that the El Niño-Southern Oscillation (ENSO) dominantly modulates δ18Otree variability across southern China.

DOI： 10.1016/j.jhydrol.2022.128484

Water Resource Management Implications for a Desert Oasis From Tree-Ring delta O-18 Variations in Populus Euphratica in Northwest China 査読有り国際共著

Li Qiang, Liu Yu, Meko David M., Nakatsuka Takeshi, Pan Yingnan, Song Huiming, Liu Ruoshi, Sun Changfeng, Fang Congxi

WATER RESOURCES RESEARCH 58 巻 ( 4 ) 2022年4月

[書評１] 樹木年輪古気候学の現状と課題－バレリー・トロエ『年輪で読む世界史』招待有り

中塚　武

史苑（立教大学史学会誌） 82 巻 ( 2 ) 頁： 155 - 161 2022年3月

気候変動と人間社会の歴史的関係から学ぶ－「変化」の速さに着目して招待有り

中塚武

学術の動向 27 巻 ( 2 ) 頁： 31 - 35 2022年2月

気候変動と人間社会の歴史的関係から学ぶ

中塚武

学術の動向 27 巻 ( 2 ) 頁： 2_31 - 2_35 2022年2月

記述言語：日本語出版者・発行元：公益財団法人日本学術協力財団

樹木年輪等を使った高時間分解能での古気候復元の進展で、気候変動の自然科学的メカニズムが理解されると同時に、気候変動が人間社会に与えた影響についても詳細に明らかになってきた。その中では「数十年周期」での気候変動の振幅拡大が飢饉や紛争を生み、やがて社会体制の転換を促すという普遍的なメカニズムの存在が示唆されている。前近代の農業社会では気候変動が農業生産量を変化させて社会に大きな影響を与えるが、「数年周期」の変動であれば穀物備蓄で対応でき、「数百年周期」の変動なら出生率の調整や技術開発に時間的余裕がある。しかし「数十年周期」の変動の場合は、気候環境の好適期に拡大した人口や生活水準が気候環境の悪化期に維持できなくなり社会が危機に陥ったと考えられる。これは温暖化を含む現在の地球環境問題と時間スケールも含めて同じ構図であり、その破滅的な影響を回避するために歴史の教訓に学ぶことが求められている。

DOI： 10.5363/tits.27.2_31

奄美リュウキュウマツ年輪酸素同位体比データと海洋変動指数との関連性

増岡晃大, 庄建治朗, 中塚武, 李貞

水文・水資源学会研究発表会要旨集 35 巻 ( 0 ) 頁： 115 2022年

記述言語：日本語出版者・発行元：水文・水資源学会

樹木年輪セルロース酸素同位体比は過去の気候変動をよく反映していることが確かめられている。近年では，年輪に含まれる酸素同位体比の測定手法の発達により，より純粋な気象因子との結びつきを検討できる可能性が期待されている．一方で樹木年輪の既往研究の多くは１年輪の測定により行われており，１年の時間分解能を持つデータが一般的である．そのため気候変動や海洋変動が日本陸域へ及ぼす季節ごとの影響を検討することが困難な場合がある．本研究では１年輪を年層内分割し得られた酸素同位体比データを用いて，気象代替データの時間分解能向上と年輪から考えられる海洋変動による陸域での季節変動について検討する．奄美大島の樹齢２００年のリュウキュウマツ３個体を対象として、年輪を形成するセルロースの抽出を行う。セルロース試料から測定サンプルを切り分ける際に、各年輪を成長方向へ分割する。測定データを用いて海洋変動が南西諸島陸域にもたらす影響を検討するために複数の海洋因子との相関分析を行う．結果としてENSO、PDOとの強い関連は得られなかった。一部年層内の成長期の終わり（11月頃）に相当する部分の酸素同位体比とENSOの間で正相関が得られた。ラニーニャ発生時期に奄美周辺の11月頃の日照時間が低下することが、同位体比変動に現れたと考えられる。一方でNPGOに関しては、1年遅いNPGOと梅雨入りに相当する部分の酸素同位体比、４年先行したNPGOと年層内の成長期の始まり（4月頃）に相当する部分の酸素同位体比との正相関が得られた。先行研究で東北地方を対象とした年輪同位体比と初夏の報告があり、東北地方のみならず南西諸島にも関連した指標であると考えられる。以上のように年輪の年層内分割は季節性の代替データを提供するとともに、大規模な海洋変動が陸域へ及ぼす関係を検討するのに有効な手段になると考えられる。

DOI： 10.11520/jshwr.35.0_115

樹木年輪古気候学の現状と課題：バレリー・トロエ『年輪で読む世界史』

中塚武

史苑 82/2 巻頁： 155 - 161 2022年

纒向遺跡の出土材年輪年代決定に向けて―酸素同位体比の年層内変動解析

中塚武

纒向学研究 10 巻頁： 309 - 316 2022年

温暖化が駆動する大気海洋相互作用－樹木とサンゴの年輪共同研究の重要性

中塚武

月刊海洋 622 巻頁： 441 - 451 2022年

樹木年輪の水素・酸素同位体比の統合による長期気候変動の復元

中塚武

月刊地球 44 巻頁： 255 - 266 2022年

シリーズ『気候変動から読みなおす日本史』をめぐって

中塚武, 三木敦朗

日本の科学者 57 巻 ( 1 ) 頁： 46 - 51 2022年

[書評] 樹木年輪古気候学の現状と課題－バレリー・トロエ『年輪で読む世界史』

中塚武

史苑 82 巻頁： 155 - 161 2022年

樹木年輪酸素同位体比の周期性からみた「高地性集落」の背景

中塚武

古代文化 74 巻頁： 68 - 75 2022年

Spatial synchrony in delta O-18 time-series from a tree-ring network are driven by synchronous hydroclimate variability in the transitional zone of the Asian summer monsoon 査読有り国際共著国際誌

Fan Haowen, Gou Xiaohua, Nakatsuka Takeshi, Li Zhen, Su Jiajia, Sano Masaki, Liu Wenhuo, Fang Keyan

AGRICULTURAL AND FOREST METEOROLOGY 311 巻 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Owing to the increased need to assess global forest behavior under changing climatic conditions within a long-term context, spatial coherence in tree-ring records is of widespread interest. Spatial networks of tree growth have been widely discussed from regional to global scales, but few studies have reported stable oxygen isotopes in networks of tree rings (δ18Otree), thus impeding a comprehensive hydroclimatic interpretation of δ18Otree records over large spatial scales, i.e., isoscapes. In this study, a network of four annually resolved δ18Otree chronologies (1805–2016) was developed for Southwest China, the transitional zone of the Asian summer monsoon, to test spatial coherence in δ18Otree variations and to explore the climatic factors driving synchrony at different spatial scales. The quantitative analyses show that the four chronologies exhibit consistent annual variations, with the first principal component (PC1) accounting for 70% of the total variance, which uniformly respond to local relative humidity (RH) and precipitation δ18O during the monsoon season. This confirms the spatial coherence in δ18Otree records. Furthermore, significant inter-site correlations of local RH and precipitation δ18O are also detected, revealing that it is the regionally homogeneous year-to-year variations in the hydroclimate that should be responsible for spatial coherence. For a larger spatial perspective, spatial correlation analyses reveal that the most prominent correlations between δ18Otree and hydroclimate fields occur in the Indochina Peninsula, in which δ18Otree changes are synchronized with those in Southwest China and the synchrony temporally varies with the Indian summer monsoon (ISM) intensity, indicating that coherent δ18Otree variations are linked to ISM-related moisture transport. In addition, δ18Otree records have shown strong in-phase relationships with the natural variabilities of the ISM and El Niño-Southern Oscillation (ENSO) across interannual and interdecadal timescales over the last 150 years, suggesting that spatial coherence in δ18Otree records can be utilized to reflect the long-term history of large-scale atmospheric circulation.

DOI： 10.1016/j.agrformet.2021.108687

あらゆる周期の気候変動のシームレスな復元－文理双方が見過ごしてきた数十年周期変動の発見－招待有り

中塚武

日本地球化学会年会要旨集 68 巻 ( 0 ) 頁： 53 2021年9月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）出版者・発行元：一般社団法人日本地球化学会

樹木年輪の酸素と水素の同位体比を組み合わせることで、中部日本の夏の気候の変動を過去2600年間に亘って、あらゆる周期で復元することに成功した。そのデータを周波数分解することにより、約400年に一度、数十年周期の気候変動の振幅が拡大し、その都度、東アジアの社会転換が促されてきたことが、初めて明らかとなった。総合地球環境学研究所の文理融合研究の成果をもとに、その発見の自然科学及び人文科学的意義について議論する。

DOI： 10.14862/geochemproc.68.0_53

Onset and maturation of Asian summer monsoon precipitation reconstructed from intra-annual tree-ring oxygen isotopes from the southeastern Tibetan Plateau

Xu Chenxi, Zhu Haifeng, Wang S-Y Simon, Shi Feng, An Wenling, Li Zhen, Sano Masaki, Nakatsuka Takeshi, Guo Zhengtang

QUATERNARY RESEARCH 103 巻頁： 139 - 147 2021年9月

記述言語：日本語出版者・発行元：Quaternary Research (United States)

We present a long-term seasonal tree ring cellulose oxygen isotope (δ18Oc) time series created by analyzing four segments (S1, S2, S3, and S4) per year during the period of 1951-2009 from southeastern Tibetan Plateau. This intraseasonal δ18Oc reveals the onset and mature phase of the summer monsoon precipitation in this region. Analysis indicates that the δ18Oc of S1 has the strongest correlation with precipitation during the regional monsoon onset (29-33 pentads, May 21-June 10, r =-0.69), and the δ18Oc values for S2, S3, and S4 correlate strongly with June, July, and August precipitation, respectively. Combined δ18Oc of S2, S3, and S4 shows the most robust correlation (r =-0.82) with the mature-phase monsoon precipitation (June-July-August, JJA), passing rigorous statistical tests for calibration and verification in dendroclimatology. These results demonstrate the feasibility in using long-term intraseasonal δ18Oc to reconstruct the Asian summer monsoon's intraseasonal variations.

DOI： 10.1017/qua.2020.28

Oxygen Isotopes in Tree Rings from Greenland: A New Proxy of NAO 査読有り国際共著国際誌

Xu Chenxi, Buckley Brendan M., Wang Shih-Yu Simon, An Wenling, Li Zhen, Nakatsuka Takeshi, Guo Zhengtang

ATMOSPHERE 12 巻 ( 1 ) 2021年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Atmosphere

We present the first Greenlandic tree ring oxygen isotope record (δ18OGTR), derived from four birch trees collected from the Qinguadalen Valley in southwestern Greenland in 1999. Our δ18O record spans from 1950–1999 and is significantly and positively correlated with winter ice core δ18O from southern Greenland. δ18OGTR records are positively correlated with southwestern Greenland January–August mean temperatures. North Atlantic Oscillation (NAO) reconstructions have been developed from a variety of proxies, but never with Greenlandic tree rings, and our δ18OGTR record is significantly correlated with NAO (r = −0.64), and spatial correlations with sea-level pressure indicate a classic NAO pressure seesaw pattern. These results may facilitate a longer NAO reconstruction based on long time series of tree ring δ18O records from Greenland, provided that subfossil wood can be found in areas vacated by melting glaciers.

DOI： 10.3390/atmos12010039

大規模土砂移動発生履歴の高精度復元に向けた埋没樹木の年代測定－歴史時代に中部山岳地域で発生した事例－査読有り

山田隆二・木村　誇・苅谷愛彦・佐野雅規・對馬あかね・李　貞・中塚　武・國分（齋藤）陽子・井上公夫

砂防学会誌 73 巻頁： 3 - 14 2021年1月

Delayed warming in Northeast China: Insights from an annual temperature reconstruction based on tree-ring delta O-18 査読有り国際共著国際誌

Li Qiang, Liu Yu, Nakatsuka Takeshi, Liu Ruoshi, Cai Qiufang, Song Huiming, Wang Shengjie, Sun Changfeng, Fang Congxi

SCIENCE OF THE TOTAL ENVIRONMENT 749 巻頁： 141432 2020年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Science of the Total Environment

Global warming has had an unprecedented impact on environmental changes and thus human life in mid-high latitude regions. As one of the areas most affected by global warming, Northeast China has suffered from a series of ecological crises, including warming-induced water deficits, permafrost thaw, and extended growing seasons. The change in annual average temperature (annual T) variations in Northeast China since the Industrial Revolution are still not fully understood, mainly because of the lack of long-term instrumental data and high-resolution annual T reconstructions. Here, we present the first annual T reconstruction (r = −0.683, p <.001, n = 60) for 1818–2012 in Northeast China, which may also be the first temperature reconstruction based on tree-ring δ18O in China. The reconstruction is significantly related to temperature variations over mid-high latitude Eurasia and agree (p <.01) with several long-term hydroclimatic reconstructions in the surrounding area. When the internal variability in the reconstruction was high, the decadal to multidecadal cycles were significant. Further analysis found that the reconstruction was mainly affected by the East Asian Summer Monsoon (EASM) and North Atlantic Oscillation (NAO). The reconstruction was significantly negatively correlated with several time series of annual T in the Northern Hemisphere, which showed that there is a substantial difference in annual T between Northeast China and other regions of the Northern Hemisphere. The difference mainly existed before the 1950s. From the 1850s to the 1950s, the annual T in Northeast China decreased slightly. However, extreme warming began in the 1950s in Northeast China, and this warming has been unprecedented during the past two centuries. If the warming trend since the 1950s continues, then it will lead to devastating disasters to forest and permafrost ecosystems in Northeast China.

DOI： 10.1016/j.scitotenv.2020.141432

PubMed

Unstable relationship between tree-ring delta O-18 in the transitional zone of the Asian summer monsoon and the Indian summer monsoon 査読有り国際共著国際誌

Fan Haowen, Gou Xiaohua, Su Jiajia, Liu Wenhuo, Gao Linlin, Nakatsuka Takeshi, Li Zhen, Sano Masaki, Lin Wei

JOURNAL OF HYDROLOGY 590 巻 2020年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Hydrology

The Asian Summer Monsoon system (ASM) affects a large population in the monsoonal Asia. Previous studies have thoroughly discussed the temporally unstable response of tree-ring oxygen isotope (δ18O) to the regional climate variables and ocean–atmosphere interaction modes, however, the response to the ASM remains ambiguous. In this study, an annually resolved tree-ring δ18O chronology is developed from eastern Yunnan-Guizhou Plateau, in the transitional zone of the ASM. Based on the results from response analyses, the climatic controls of tree-ring δ18O is considered to be the moisture-related variables of the monsoon season. Spatial correlations suggest that in the study area, the water vapor is mainly originated from the Bay of Bengal and transported by the Indian Summer Monsoon (ISM). Furthermore, the temporal stability in relationships between the tree-ring δ18O and the ISM variability are explored. Our findings suggest that on interannual to decadal timescales, the tree-ring δ18O is significantly anti-correlated, but temporally unstable with respect to the ISM. The strength of interannual relationship is affected by the ISM intensity, which is modulated by the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) variability. Moreover, the strength of decadal relationship is associated with the phase shift of the Pacific Decadal Oscillation (PDO). Additionally, the decreasing trend of tree-ring δ18O after the late 1970 s that diverges from the simultaneous normal level of the ISM is caused by the isotopically-depleted trend in upstream precipitation of the moisture source. The opposite patterns of correlations between the tree-ring δ18O and the ENSO and IOD in recent decades demonstrate that the regional hydroclimate in the study region has been undergoing significant secular variations that are characterised by an increasing effect of the IOD and a decreasing effect of the ENSO. The findings from this study further improve our understanding of the tree-ring δ18O response to the ASM, at multi-time scales, and shed light on the impact of the ASM on regional hydroclimate variability, across the transitional zone of the ASM.

DOI： 10.1016/j.jhydrol.2020.125522

Synchronizations of tree-ring delta O-18 time series within and between tree species and provinces in Korea: a case study using dominant tree species in high elevations 査読有り国際共著国際誌

Choi En-Bi, Sano Masaki, Park Jun-Hui, Kim Yo-Jung, Li Zhen, Nakatsuka Takeshi, Hakozaki Masataka, Kimura Katsuhiko, Jeong Hyun-Min, Seo Jeong-Wook

JOURNAL OF WOOD SCIENCE 66 巻 ( 1 ) 2020年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Wood Science

The current study was initiated to test the synchronizations of tree-ring δ18O (hereafter δ18OTR) time series within and between tree species and provinces, which are about 144 km apart from each other in Korea. For the test, a 50-year δ18OTR time series (1966–2015) was developed using four trees from each tree species which are Pinus densiflora and Quercus mongolica from Songnisan National Park and Taxus cuspidata, Pinus koraiensis, Abies koreana, and Quercus mongolica from Jirisan National Park. Their synchronizations were evaluated using t-value, Gleichläufigkeit (Glk), and Expressed Population Signal (EPS). The mean t-values and Glk scores within the tree species ranged 5.2–11.2 (p < 0.05) and 69–83%, and between the tree species ranged 6.1–13.2 (p < 0.05) and 73–81%, respectively. The mean t-value and Glk score between the regions were 4.3 (p < 0.05) and 72%, respectively. Furthermore, the EPS showed higher than 0.85, which is the generally accepted threshold value in dendrochronology, except for Q. mongolica at Songnisan National Park for which the value is 0.83 calculated by only two δ18OTR time series. Based on the statistical results, we concluded that a δ18OTR chronology established using more than four trees could serve as a promising reference for dating an undated wood without considering the tree species, as well as for research on climate in the past.

DOI： 10.1186/s10086-020-01901-3

An assessment of diatom assemblages in the Sea of Okhotsk as a proxy for sea-ice cover 査読有り国際共著国際誌

Nakamura Hiroki, Okazaki Yusuke, Konno Susumu, Nakatsuka Takeshi

JOURNAL OF MICROPALAEONTOLOGY 39 巻 ( 1 ) 頁： 77 - 92 2020年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Micropalaeontology

Knowledge of past variations in sea-ice extent is crucial for understanding the relationship between climate change and changes in sea ice. Diatom assemblages could be applied as a proxy for paleo-sea-ice extent; this requires accurate information on the modern species that are indicative of sea ice. Scanning electron microscope observations were performed on modern diatom assemblages in sea ice, sinking particles, and surface sediments in the Sea of Okhotsk. A sea-ice sample was collected in the southwestern Sea of Okhotsk near Hokkaido island in February 2013. Fragilariopsis cylindrus was the dominant diatom species in the sea-ice sample, accounting for 87 % of the total diatom assemblage. Time-series sediment traps were deployed during 1998-2000 at two stations, M4 and M6, off Sakhalin island. Total diatom fluxes ranged from 105 to 108 valves m-2 d-1 with noticeable seasonality. During the sea-ice covering period, the total diatom flux decreased by 1 or 2 orders of magnitude. The highest diatom fluxes were observed in spring and summer. The diatom species composition in sinking particles also showed pronounced seasonal changes. During summer and fall, the Shionodiscus trifultus group and Neodenticula seminae were the major diatom taxa. During the sea-ice covering period, Fragilariopsis cylindrus and Bacterosira bathyomphala resting spores were abundant. Both the sea-ice-related species showed similar flux patterns except for the spring bloom after sea-ice retreat: F. cylindrus fluxes exhibited pronounced spring bloom peaks of 108 valves m-2 d-1; in contrast, the fluxes of Bacterosira bathyomphala resting spores during the spring bloom were 1 order of magnitude lower than those of F. cylindrus. Surface-sediment core XP98-MC4 was obtained near station M6 sediment-trap site off Sakhalin island. The relative abundance of Fragilariopsis cylindrus in the surface-sediment diatom assemblage was only 6.4 %, markedly lower than that in the sediment-trap samples (43.4 %). In the surface sediment, the relative abundances of diatom taxa with heavily silicified valves such as B. bathyomphala resting spores, Shionodiscus variantius, and Thalassionema nitzschioides were greater than their relative abundances in sinking particles.

DOI： 10.5194/jm-39-77-2020

A 338-year tree-ring oxygen isotope record from Thai teak captures the variations in the Asian summer monsoon system 査読有り国際共著国際誌

Pumijumnong Nathsuda, Brauning Achim, Sano Masaki, Nakatsuka Takeshi, Muangsong Chotika, Buajan Supaporn

SCIENTIFIC REPORTS 10 巻 ( 1 ) 頁： 8966 2020年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Scientific Reports

A 338-year oxygen isotope record from teak tree-ring cellulose collected from Mae Hong Son province in northwestern Thailand was presented. The tree-ring series preserves the isotopic signal of the regional wet season rainfall and relative humidity. Tree-ring δ18O correlates strongly with regional rainfall from May to October, showing coherent variations over large areas in Southeast Asia. We reconstructed the summer monsoon season (May to October) rainfall based on a linear regression model that explained 35.2% of the actual rainfall variance. Additionally, we found that in the 19th century, there was a remarkable drought during many years that corresponded to regional historic drought events. The signals of the June to September Indian summer monsoon (ISM) for the period between 1948 and 2009 were clearly found. Spatial correlations and spectral analyses revealed a strong impact of the El Niño-Southern Oscillation (ENSO) on tree-ring δ18O. However, ENSO influenced the tree-ring δ18O more strongly in the 1870–1906, 1907–1943, and 1944–1980 periods than in the 1981–2015 period, which corresponded to periods of weaker and stronger ISM intensity.

DOI： 10.1038/s41598-020-66001-0

PubMed

Oxygen stable isotopes of a network of shrubs and trees as high-resolution plaeoclimatic proxies in Northwestern China 査読有り国際共著国際誌

Li Qiang, Liu Yu, Nakatsuka Takeshi, Zhang Qi-Bin, Ohnishi Keiko, Sakai Akiko, Kobayashi Osamu, Pan Yingnan, Song Huiming, Liu Ruoshi, Sun Changfeng, Fang Congxi

AGRICULTURAL AND FOREST METEOROLOGY 285 巻 2020年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Agricultural and Forest Meteorology

Tree rings play an important role in high-resolution paleoclimate reconstruction over large areas. Nevertheless, the sampling sites of most existing tree-ring networks are unevenly distributed due to the limitations of the availability of appropriate tree species and sampling conditions. In light of the good spatial representation provided by tree-ring stable oxygen isotope ratio (δ18O), we selected several shrubs (Hippophae rhamnoides L.) found in near-glacier valleys, conifer (Picea crassifolia Komarov) trees in alpine meadows, and broad-leaved (Populus euphratica Olivier) trees found in deserts. Although the three sampling sites were each 250–360 km apart, with varied site conditions and very distinct species, we observed coherent variations in the δ18O of the three species within a common time interval. The average correlation coefficient was found to be 0.674 (p < 0.001, n = 30) among annual-ring δ18O series of three species. All annual-ring δ18O of three species demonstrated significant negative correlations with relative humidity (RH) and precipitation, and significant positive correlations with temperature, in spring and summer. The correlation coefficient between the first principal component (PC1) of the δ18O variations in the three species and the regional summer (June to August) RH was found to be −0.855 (p < 0.001, n = 30). In addition, PC1 showed variations similar to those of δ18O in precipitation. Spatial correlation demonstrated that PC1 represents the hydroclimatic variability that occurs in most of central-western China. Significant correlations with sea-level pressure and several East Asian Summer Monsoon indices indicated that PC1 was affected by the large-scale atmospheric circulation pattern and could be used as an indicator of monsoon moisture. PC1 correlated significantly with ten annually resolved hydroclimatic series in central-western China, demonstrating the potential of establishing a tree-ring climate network with uniform spatial distribution using multi-species tree-ring δ18O. The results from these series suggest that an abrupt climate change occurred in 1979. After 1979, PC1 correlated significantly with the summer-season EI Nino Modoki index (r = 0.474, p < 0.02, n = 24). This implied that the effect of the central Pacific ENSO on the variability in monsoon moisture in China became more prominent after the abrupt climate change in 1979.

DOI： 10.1016/j.agrformet.2020.107929

Climate variability over the past 100 years in Myanmar derived from tree-ring stable oxygen isotope variations in Teak 査読有り国際共著国際誌

Pumijumnong Nathsuda, Muangsong Chotika, Buajan Supaporn, Sano Masaki, Nakatsuka Takeshi

THEORETICAL AND APPLIED CLIMATOLOGY 139 巻 ( 3-4 ) 頁： 1401 - 1414 2020年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Theoretical and Applied Climatology

We present a 100-year oxygen isotope record from teak tree-ring cellulose (δ18O), originating from a site in southern Myanmar that preserves the isotopic ratios of the regional wet season’s rainfall. Tree-ring δ18O correlates strongly with regional rainfall during the months of May to October (r = − 0.353, p < 0.01). We found the tree-ring δ18O had clear signals of the June to September Indian Summer Monsoon (ISM) over the years 1948–1998 (r = − 0.53, p < 0.01). The δ18O has a significant and negative correlation with the minimum temperature in September and has a significant positive correlation with maximum temperature in November and December. The study found that δ18O has a significant positive correlation with the difference between the maximum temperature and the minimum temperature (DTR) in August to October. Based on our results, it can be concluded that tree-ring δ18O in teak in southern Myanmar is controlled by the amount of rainfall during the monsoon season and the temperature in the November and December. Spatial correlation and spectral analyses revealed a strong impact of the El Niño-Southern Oscillation (ENSO) on tree-ring δ18O of teak. In addition, tree-ring δ18O also captures the signal of the Indian Ocean Dipole (IOD).

DOI： 10.1007/s00704-019-03036-y

酸素同位体比年輪年代法－高精度編年への挑戦招待有り

中塚　武

季刊考古学 150 巻頁： 142-145 2020年2月

Reconstruction of multi-millennial summer climate variations in central Japan by integrating tree-ring cellulose oxygen and hydrogen isotope ratios 査読有り国際共著国際誌

Nakatsuka, T, Sano, M, Li, Z, Xu, C, Tsushima, A, Shigeoka, Y, Sho, K, Ohnishi, K, Sakamoto, M, Ozaki, H, Higami, N, Nakao, N, Yokoyama, M, Mitsutani, T

Climate of the Past Discussion 2020年2月

Specific response of earlywood and latewood δ18O from the east and west of Mt. Qomolangma to the Indian summer monsoon. 査読有り国際共著国際誌

An W, Xu C, Liu X, Tan N, Sano M, Li M, Shao X, Nakatsuka T, Guo Z

The Science of the total environment 689 巻頁： 99 - 108 2019年11月

Oxygen isotope ratios of subalpine conifers in Jirisan National Park, Korea and their dendroclimatic potential. 査読有り国際共著国際誌

Jeong-Wook Seo, Masaki Sano, Hyun-Min Jeong, Kwang-Hee Lee, Hong-Chul Park, Takeshi Nakatsuka, Chang-Seob Shin

Dendrochronologia 57 巻 2019年10月

Sampling strategy and climatic implication of tree-ring cellulose oxygen isotopes of Hippophae tibetana and Abies georgei on the southeastern Tibetan Plateau. 国際共著国際誌

Xu C, Zhu H, Nakatsuka T, Sano M, Li Z, Shi F, Liang E, Guo Z

International journal of biometeorology 63 巻 ( 5 ) 頁： 679 - 686 2019年5月

Increased drought events in southwest China revealed by tree ring oxygen isotopes and potential role of Indian Ocean Dipole. 査読有り国際共著国際誌

Xu C, An W, Wang SS, Yi L, Ge J, Nakatsuka T, Sano M, Guo Z

The Science of the total environment 661 巻頁： 645 - 653 2019年4月

Increased variability of Thailand's Chao Phraya River peak-season flow and its association with ENSO variability: Evidence from tree ring δ18O. 査読有り国際共著国際誌

Chenxi Xu, Brendan M. Buckley, Parichart, Promchote, S. Y, Simon Wang, Nathsuda Pumijumnong, Wenling An, Masaki Sano, Takeshi Nakatsuka, Zhengtang Guo

Geophysical Research Letters 2019年4月

島根県出土材の酸素同位体比年輪年代法による年代決定

中塚武

古代文化研究（島根県古代文化センター） 27 巻頁： 1 - 16 2019年

酸素同位体比年輪年代法による高屋敷館遺跡東壕橋脚の年代検証

木村勝彦, 佐野雅規, 中塚武

青森市埋蔵文化財調査報告書 124 巻頁： 77 - 80 2019年

Cellulose oxygen isotopic composition of teak (Tectona grandis) collected from Java Island: a tool for dendrochronological and dendroclimatological analysis 国際共著国際誌

Hisamochi Ryo, Watanabe Yumiko, Sano Masaki, Nakatsuka Takeshi, Kurita Naoyuki, Matsuo-Ueda Miyuki, Yamamoto Hiroyuki, Tazuru Suyako, Sugiyama Junji, Subiyanto Bambang, Marsoem Sri Nugroho, Tsuda Toshitaka, Tagami Takahiro

DENDROCHRONOLOGIA 52 巻頁： 80 - 86 2018年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Dendrochronologia

The oxygen isotopic composition (δ18O) of tree-ring cellulose has been recognized as a powerful tool for dendroclimatological and dendrochronological investigations in Asia. Only a few studies of cellulose δ18O so far published, however, have been conducted in Indonesia, and the spatial coherence of cellulose δ18O has yet to be clarified. In this study we measured cellulose δ18O of teak (Tectona grandis) collected from four sites on Java Island to evaluate the similarity between the different teak δ18O values and the potential for using teak δ18O both as a climate proxy and as a tool for cross-dating. Cellulose δ18O time series of Javanese teaks were found to be significantly correlated in all of the comparisons between sites, even between sites separated by a distance as great as 400 km. While significant correlations did not appear in the ring width data between our samples (expressed population signal (EPS) = 0.64; Rbar = 0.23; sample depth = 10), they were found between the cellulose δ18O values (EPS = 0.89; Rbar = 0.58; sample depth = 10). These results suggest that teak δ18O variations have higher spatial coherence and might be a useful tool for cross-dating. A significant negative correlation was observed between cellulose δ18O and the relative humidity/precipitation during the rainy season, indicating that the cellulose δ18O of Javanese teak is an effective proxy for relative humidity/precipitation during the rainy season. Cellulose δ18O was found to be positively correlated with precipitation during the dry season preceding the growing season, whereas it showed no correlations with the temperature and Palmer Drought Severity Index (PDSI), the key constraints of δ18O on the Indochina Peninsula.

DOI： 10.1016/j.dendro.2018.09.010

樹木年輪セルロースの酸素・水素同位体比の統合による中部日本の短周期及び長周期の夏季降水量変動の復元

East Asian Summer Monsoon moisture sustains summer relative humidity in the southwestern Gobi Desert, China: evidence from δ18O of tree rings. 査読有り

Qiang Li, Yu Liu, Takeshi Nakatsuka, Keyan Fang, Huiming Song, Ruoshi Liu, Changfeng Sun, Gang Li, Ke Wang

Climate Dynamics 2018年10月

Evaluation of the effect of the 2011 Tsunami on coastal forests by means of multiple isotopic analyses of tree-rings. 国際共著国際誌

Lopez Caceres ML, Nakano S, Ferrio JP, Hayashi M, Nakatsuka T, Sano M, Yamanaka T, Nobori Y

Isotopes in environmental and health studies 54 巻 ( 5 ) 頁： 494 - 507 2018年10月

Inter-annual and multi-decadal variability of monsoon season rainfall in central Thailand during the period of 1804-1999-inferred from tree ring oxygen isotopes. 査読有り

Chenxi Xu, Nathsuda Pumijumnong, Takeshi Nakatsuka, Masaki Sano, Zhengtang Guo

International Journal of Climatology 38 巻 ( 15 ) 頁： 5766-5776 2018年9月

Decreasing Indian summer monsoon on the northern Indian sub-continent during the last 180 years: evidence from five tree-ring cellulose oxygen isotope chronologies. 査読有り

Chenxi Xu, Masaki Sano, Ashok Priyadarshan Dimri, Rengaswamy Ramesh, Takeshi Nakatsuka, Feng Shi, and Zhengtang Guo

Climate of the Past 14 巻頁： 653-664 2018年5月

Early summer precipitation in the lower Yangtze River basin for AD 1845-2011 based on tree-ring cellulose oxygen isotopes 査読有り

Chenxi Xu, Jiangfeng Shi, Yesi Zhao, Takeshi Nakatsuka, Masaki Sano, Shiyuan Shi and Zhengtang Guo

Climate Dynamics 2018年4月

多賀城跡出土西辺柵木の樹種招待有り

箱崎真隆・木村勝彦・中塚　武

多賀城跡（宮城県多賀城跡調査研究所年報） 2017 巻頁： 40-41 2018年3月

年輪酸素同位体比分析による多賀城跡西辺の柵木の年代決定招待有り

斉藤颯人, 木村勝彦, 箱崎真隆, 佐野雅規, 對馬あかね, 李貞, 中塚武

多賀城跡（宮城県多賀城跡調査研究所年報） 2017 巻頁： 42-45 2018年3月

三内丸山遺跡出土木材の酸素同位体分析招待有り

小林謙一・木村勝彦・佐野雅規・箱崎真隆・中塚　武

特別史跡三内丸山遺跡年報 21 巻頁： 43-61 2018年3月

Age determination on a catastrophic rock avalanche using tree-ring oxygen isotope ratios - the scar of a historical gigantic earthquake in the Southern Alps, central Japan 査読有り

Ryuji Yamada, Yoshihiko Kariya, Takashi Kimura, Masaki Sano, Zhen LI, Takeshi Nakatsuka

Quaternary Geochronology 44 巻頁： 47-54 2018年3月

樹木年輪セルロースの酸素同位体比が明らかにした日本史の背後にある気候変動．

中塚武

海洋化学研究 31 巻頁： 101 - 106 2018年

三内丸山遺跡出土木材の酸素同位体分析と年代研究

小林謙一, 木村勝彦, 箱崎真隆, 佐野雅規, 中塚武

特別史跡三内丸山遺跡年報 21 巻頁： 62 - 80 2018年

Relationship between the Northern Paciic Gyre Oscillation and tree-ring cellulose oxygen isotopes in northeastern Japan. 査読有り

Wataru Sakashita, Hiroko Miyahara, Yusuke Yokoyama, Takahiro Aze, Stephen P. Obrochta and Takeshi Nakatsuka

Geoscience Letter 4 巻 ( 29 ) 2017年12月

Fine structure and reproducibility of radiocarbon ages of middle to early modern Japanese tree rings. 査読有り

Minoru Sakamoto, Masataka Hakozaki, Nanae Nakao and Takeshi Nakatsuka

Radiocarbon 59 巻頁： 1907-1917 2017年12月

高分解能古気候データを『日本書紀』の解釈に利用する際の留意点招待有り

中塚　武

日本書紀研究 32 巻頁： 155-171 2017年11月

Negligible local-factor influences on tree ring cellulose δ18O of Qilian juniper in the Animaqing Mountains of the eastern Tibetan Plateau. 査読有り

Chenxi Xu, Xuemei Shao, Wenling An, Takeshi Nakatsuka, Yong Zhang, Masaki Sano and Zhengtang Guo

Tellus B: Chemical and Physical Meteorology 69 巻頁： 1391663 2017年11月

原始・古代史の時間認識と気候変動招待有り

中塚　武

歴博 204 巻頁： 15-18 2017年9月

中塚武, 佐野雅規, 李貞, 對馬あかね, 重岡優希

日本地球化学会年会要旨集 64 巻 ( 0 ) 2017年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本地球化学会

本州の中部及び近畿地方の多数の地点から得られた、様々な時代の約70個体の長樹齢(百～九百年)の木材年輪試料から、年層毎にセルロースを抽出して酸素同位体比を測定し、過去2600年間に及ぶ高精度の酸素同位体比クロノロジーを完成させると共に、同時に測定した水素同位体比と組み合わせることで、酸素同位体比に含まれる樹齢効果を理論的に削除し、純粋に気候(降水量)変動の成分のみを計算することに成功した。その方法の詳細、及び得られた成果の気候学的、歴史学的、考古学的意義について紹介する。

DOI： 10.14862/geochemproc.64.0_15

Moisture source signals preserved in a 242-year tree-ring δ18O chronology in the western Himalaya. 査読有り

Masaki Sano, A P Dimri, R. Ramesh, Chenxi Xu, Zhen Li, Takeshi Nakatsuka

Global and Planetary Change 157 巻頁： 73-82 2017年8月

Hydroclimate reconstruction in central Japan over the past four centuries from tree-ring cellulose δ18O. 査読有り

Wataru Sakashita, Hiroko Miyahara, Yusuke Yokoyama, Takahiro Aze, Takeshi Nakatsuka, Yasuharu Hoshino, Motonari Ohyama, Hitoshi Yonenobu, Keiji Takemura

Quaternary International 2017年6月

Assessment of sungkai tree-ring delta O-18 proxy for paleoclimate reconstruction in western Java, Indonesia 査読有り国際共著国際誌

Harada Mao, Watanabe Yumiko, Nakatsuka Takeshi, Tazuru-Mizuno Suyako, Horikawa Yoshiki, Subiyanto Bambang, Sugiyama Junji, Tsuda Toshitaka, Tagami Takahiro

QUATERNARY INTERNATIONAL 432 巻頁： 33 - 38 2017年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Quaternary International

To assess the reproducibility of sungkai δ18O as paleoclimate proxies, we measured annual δ18O variations of two sungkai trees that had been collected in the same area as in a previous study. Two sungkai δ18O variations showed significant mutual correlation (r = 0.80; P < 0.001) and correlation with results of earlier analyses, suggesting that external climatic factors affect the δ18O values of sungkai. The annual δ18O of SungkaiNAN7 shows significant, positive correlation with temperature, sunlight hours, and air pressure. It shows significant, negative correlation with relative humidity and SOI. Moreover, the seasonal δ18O variation acquired during severe drought of the 1997–1998 El Niño event shows that the maximum δ18O value around 1997 latewood corresponds to the rainfall/relative humidity minimum and corresponds to the temperature/sunlight hours/air pressure maximum with a considerable time lag.

DOI： 10.1016/j.quaint.2015.03.038