研究者詳細 - 中塚　武

論文 - 中塚　武

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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

CiNii Research

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

Web of Science

Scopus

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

CiNii Research

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

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Scopus

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

Web of Science

Scopus

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

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Scopus

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

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Scopus

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

Web of Science

Scopus

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

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Scopus

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