Variations of atmospheric 14C andthe climate in Yayoi period
太陽活動は弥生時代の気候にどう影響したのか？
Mineo Imamura

The talk aims at obtaining some hints of
the Sun’s influence on climate in history
and hopefully in the future through thecorrelation between 14C records in treerings and the climatic proxy data in EastAsia.

Sunspots have been depicted inhistory as early as more than 2000years ago.

Wall Painting Depicting Sun and Moon (Fragment), Han Dynasty, 1c.BC‐1c.AD:
from “The Birth of Chinese Civilization”, Tokyo National Museum, p.128, 2010.

1. 14C production rate in the earth’s
atmosphere as an indicator of pastsolar activity

Column density:
per 1 cm2

(From W F Libby, Nobel lecture, 1960)

14C production rates, P(14C)

14C in the atmosphere has its origin mostly inmarine 14C. It goes back to the ocean.
During the residence time (τ） of atmosphericcarbon, neutron-induced 14C is accumulated in theatmosphere, so that

Δ(14C/12C) atm -Δ(14C/12C)marine = P(14C) .τ(co2) /m12,atm+ (decay corr. terms)
P(14C) can be calculated using INTCAL datasets underassumption of constant τ and m.

INTCAL radiocarbon
calibration datasets(calibration curve)
Given for 14C dates andΔ14C
Also given for marine 14C(modeled)Obtained from tree-rings
14C dates
Evaluated by 10-yearsmean• In the 14C calibration curve, calendar ages of annual treerings are obtained by dendrochronology.
• Patterns of treering width are used to connect historicaland archaeological tree-rings. （back to ~12400 cal BP forINTCAL09）「弥生はいつから？！」（国立歴史民俗博物館）p.14, 2007より：図は光谷拓実作成.

14C has been measured

traditionally by radiometric method, butcurrently byaccelerator mass
spectrometry (AMS)

名古屋大学のAMS

Nagoya U.

U. Of Tokyo

Compact AMS（NEC, USA）

P(14C) = f (solar activity) +f (earth’s dipole moment)
Variations of atmospheric

14C production rates in the past 3500 years

１４

C production rate（２nd millennium=１）

1.40

INTCAL98

1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
0.50
-1500

-1000

-500

BC/AD

500

Cal Year（-BC/+AD）

1000

1500

2. Correlations between past climate
proxies (East Asia) and 14Cproduction rates

(“H-res” data from Bao Yang et al. GRL, GL014485, 2002)

Paleotemperature

1.00.5
0.0-0.5-1.0-1.5

Production Rate (14C)

0200

400600

800

1000

1200

1400

1600

1800

2000

Cal Year (AD)

0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

Production rate

0200

400600

800

1000

1200

Cal Year (AD)

1400

1600

1800

Solar activity →Temperature anomaly

1.5

2000

Temperature anomaly

1.5

Paleotemperature

1.00.5
0.0-0.5-1.0-1.5

Production Rate (14 C)

0200

400600

800

1000

1200

1400

1600

1800

2000

Cal Year (AD)

0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

Production rate0200

400

600

800

1000

1200

Cal Year (AD)

1400

1600

1800

2000

Temperature anomaly

1.5

Paleotemperature

1.0
0.5
0.0-0.5-1.0-1.5

Production Rate (14C)

0Temperature anomaly

1.5
1.0
0.5
0.0-0.5-1.0-1.5

200

400

600

800

0.7

0.80.9

1200

1400

1600

1800

2000

Cal Year (AD)Correlation
between temperature and P(14 C)
0.6

0.7
0.8
0.9
1.0
1.1
1.2
y 1.3
= -1.8867x + 1.8536
R2 = 0.2289
0200

1000

Production rate

950-1890AD
線形 (950-1890AD)

400
1.0P(14 C)

600
1.1

1.2

800
1.3

1000

1200Cal Year (AD)

1400

1600

1800

2000

Temperature anomaly

1.5

Paleotemperature

1.0
0.5
0.0
-0.5
-1.0
-1.5
200400

600

800

1000

1200

1400

1600

1800

2000

Cal Year (AD) Correlation between temperature and P(14C)

0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

1.5

Production rate
1-940AD

Temperature anomaly

Production Rate (14C)

00

200

400

600

800

1000

線形 (1-940AD)

1.0

y = -1.2319x + 1.134
R2 = 0.0408

0.5
0.0
-0.5
-1.0

1200
0.7

Cal Year (AD)

1400
0.8

1600
0.9
14P( C)1800
1.02000 1.2
1.1

Winter-time Temperature(Q. Ge et al., Holocene13, 933, 2003)
Temp Anomaly (℃)

1.0
0.5
0.0

-0.5
-1.0

East China (central) Winter-time Temperature-1.5Production Rate (14C)

0200

400

600

800 1000 1200
Cal Year (AD)

0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3

1400

1600

1800

2000

1600

1800

2000

Production rate

0200

400

Correlation is weak !

600

800

1000

1200

Cal Year (AD)1400

We observe that• The periods of high summer temperaturerecords in East Asia for the last 2000years
coincide with the high solar activity periods,
showing that the sun played a significant role in
the East Asian summer climate.
• There are a few exceptional periods (2/16) whenhigh summer temperature prevailed in the low
solar activity periods. (It is noted that these
exceptions have taken place in phases of strong
East Asian Monsoon estimated from stalagmitedata.)

3. Sun-climate correlations inshorter timescale

Sunspot number max.

δ18O in tree-ring cellulose of Japanesecedar from Kiso district

Rainfall (mm) reconstructed from old diaries

Rainfall/Humidity in late 18th c. to early 19th c. in Kinki& Tokai districts, Japan (from T. Nakatuka,2010)

Heliospheric magnetic field strenth HMF B

EL Nino (■） and La Nina (▲) tend to occur in low solar
magnetic activity
Cf. HMF B data from Svalgaard and Cliver(2010)←Failed crops

YearEl Nino and La Nina (from 気象庁資料（理科年表,2010))

Sea Surface Temperature (SST) distribution(Nino.3 area in red)from 佐伯理郎2001『エルニーニョ現象を学ぶ』盛山堂書店

Summer temperature (July~August)during El Nino
North Japan
East JapanlowWest JapannormalNansei-shoto
highfrom 佐伯理郎2001『エルニーニョ現象を学ぶ』盛山堂書店

Ending of Rainy Season (Baiu) during El NinoNorthJapanearlynormalCentralJapan

delayedSouthJapanfrom 佐伯理郎2001『エルニーニョ現象を学ぶ』盛山堂書店

4. East Asian summer monsoon asdemonstrated by regional offsets** atmospheric 14C difference from northernhemispheric 14C, IntCal09

14C dates in northern hemisphere. Atmospheric 14C in summer (tree growingseason) is generally assumed to beconstant throughout the mid-lattude, i.e.
Δ14C~1 permil.
. Basic assumption for radiocarbon dating.

Historical documents (papers) in Japan have given
concordant
14Ｃ年代
奥書＋書風から書写年代判定が可能な古文書等の14C dates with those expected from the description/sign（名古屋大学・小田寛貴氏による）(by courtesy of Dr. H. Oda)

奥書年代,

14C wiggle-matching of 9 single-year treerings from Miki family house, Tokusima
三木家（Regional effect= 10 14C-years)
RHC3.2w & Stuiver et al.(1998)

500

300
200

14C Age (BP)400

Probablity Distribution

100
0
1500

1550

1600

1650

1700

1750

(95.4% cf97.1% )Calibrated Age( calAD)

tpeak
1651

=
cal AD

1655〜1657

Results
cal AD
cal AD

Wiggle matching of 8 single-year samples from a Korean statue
to the IntCal04 calibration curve(Y. Kim et al., 2012)

Dendrodate
1517AD

14C wiggle matching of 6 five-year treerings from Horyuji

temple, Nara (法隆寺,NRHRJ-E）-200-100

0

100

200

RHcal3.2w & IntCal041490

IntCal04 (Reimer et al.,2004)

1440
1390
14 C Age (BP)

200

100

1340

01290
1240

-100

1190
Probablity

1140
1090
495

-200
545

595

645

695

745

795

845

895

cal AD
14C wiggle-match date is shown in relative probability for the outermost ring.

Data points given for the most probable date

14C dates of Japanese treerings are generally consistentwith INTCAL datasets
IntCal04
300 014C age (BP)

NNMSM

HKN

250 0200 0

NNIH 8C8A

HRHH C261

C569

AKNKH
150 01000BC500BC

BC/AD

Calendar Year(from H. Ozaki et al., 2009 Radiocarbon Conference, Hawaii)

AD500

However, significant deviations fromINTCAL are observed ranging up to ~70
14C-years¾Deviation in 1st~2nd century was first suggested(M.Sakamoto et al.,2003) using decadal sample ofJapanese cedars for 240BC~AD900.
¾It was confirmed in measurements withimproved precision (+/-20~30 14C-years) forJapanese cedars and cypresses (5-years treering)for 1060BC~AD400. (H.Ozaki et al. 2009, 20th
Raiocarbon conference)

240BC~AD400
Sources of INTCAL datasets for 240BC~AD400
from Stuiver and Pearson (Radiocarbon 28, 1986)
Lab code

Species

Locality

Dendro ages usedRC

Sequoia

Sequoia Natl Park,CA(36.5N, 118.5W)

AD265-AD935(decadal)SC

Sequoia

Sequoia Natl Park,CA(36.5N, 118.5W)

145BC-AD265(decadal)

BK

OakSouthern Germany

495BC-AD45

Japanese tree-rings for 240BC~AD400
Spl CodeAMS Lab

Species

Locality

Dendro ages usedHKN
Paleo LabJapanesecedarHakone, Kanagawa
Central Honshu Is.

240 BC – AD 200(5-years)

NNMSM
Paleo LabJapanesecypress

Minami-shinano, Nagano
Central Hoshu Is.

153BC – 400AD(5-years)

We find¾General correlations of wiggles
between Beijing warm time climate
proxies and 14C offsets in theJapanese tree-rings for the periods
between 240BC and 400AD.
¾Large offsets take place whentemperature is substantially high,particularly in the periods of1~200AD.

> Tan et al.(2003) reported a 2650-years paleotemperature reconstruction from stalagmite
lamina thickness in Shihua Cave, Beijing : GRL 30,1617-1620.
> Effect of rainfall was suggested(F.Ban et al.2008).
45N
Shihua Cave, Beijing, (115 56E, 39 47N）251
m above sea level at the entrance
40N
35N
30N
25N
20N
105E

115E

125E

135E

TemperatureAnomaly(.℃）

21.5
10.5
0-0.5
-1-1.5-2

Beijing Summer Temperature Record from Stalagmite (Tan et al, 2003)

150
Regional Offset
14（ C-years)

Regional Offset in Japanese Tree-rings
100
500-50
300BC

200BC

100BC

BC/AD

100AD

200AD

300AD

400AD

Callendar AgeBeijing summer temperature/precipitation proxy records (Tan et al.2003,upper) compared with the regional offsets measured for Japanese cedarsand cypress ( Both data are given in 10-years running averages)..Age
uncertainty for the proxy records : ±5-years

¾Synchronous behavior of time series
for Beijing warm time climate
proxies and 14C offsets in theJapanese tree-rings strongly
suggests the effect of Eat Asiansummer monsoon.

East Asian Summer Monsoon (EASM) isa subdivision of Asian Summer Monsoon

EASM is seasonal wind (May~August) in East Asia region mainly
caused by the temperature (pressure) difference between Tibet
plateau and Indian and western North Pacific Ocean. From Yuhuiand Chang (2005).

Beijing

Latitude-time section of 5-day mean rainfall over eastern
China (110-120E) averaged for 1961-1990. Heavy rainfall
regions are shaded (uni:mm). From Fig.7 of Yuhui andChang (2005).

Rain belt (Baiu/Meiyu) formed by
East Asian summer monsoon

Cold air (heavy)North

Warm, moist air (light)
South(from weather news, Japan)
July 5th 2012)

EASA front (Rain belt)
Average rainy season (1951-2011)
Okinawa (26N)

May 9 - June 23

South Kyushu (~31N)

May 3! - July 14

Central Japan (~35 N)

June 8 - July 21

North Japan (~39 N)

June 14 - July 28

2000 yr ago
How early did it started ? How far did it move ?

Ferrel Cell
Cold air (heavy)North

Hadley Cell
Warm, moist air (light)South5. Climates in the Yayoi period andthe role of solar activity

Yayoi period/Yayoi culture
Characterized by wet-rice agriculture, anduse of metal
Particularly, irrigated paddy-rice
technique↓Requires warm and wet climates

Winter-summer temperature difference

Prepared from 佐伯理郎2001『エルニーニョ現象を学ぶ』盛山堂書店

Spread of wet-rice cultivation in East Asiaand Japanese archipelago「弥生はいつから？！」（国立歴史民俗博物館）p.32, 2007：藤尾慎一郎作成図より作成.

The ages are estimated from radiocarbon dates ofpottery (soots) and artefacts (stakes etc.) found inarchaeological sites related with rice fields.
The ages of earliest Yayoi periods coincide with thoseof the Dolmen appeared in northern Kyushu, Japan.

(Satodabaru site, Nagasaki Pref.)Pottery used in the earliest stageof paddy-rice cultivation

Yamanotera-type：2730±40 14C BP(end of 10th c.BC～early 9th c.BC）

Yuusu I-type：2765±40 14C BP（latter half of 10th c. BC）

Itazuke I -type pottery, ca.800 BC
遠賀川系土器（板付I 、 2800年前)「弥生はいつから？！」（国立歴史民俗博物館）p.47, 2007より：藤尾慎一郎撮影.

14C dates in N. Kyushu districts in Jomon to Yayoi transition periods
14

C ages of pottery（Northen Kyushu）

3000

INTCAL04
黒川式古 Kurokawa-old type2900

黒川式新 Kurokawa-new type
山ノ寺式 Yamanotera type
夜臼Ⅰ式 Yuusu I type2700

夜臼Ⅱa式 Yuusu IIa type
夜臼 2b式 Yuusu 2b type

2600

板付Ⅰ式 Itazuke I type14

C age (BP)

2800

2500
2400
2300
1100BC

1000BC

900BC

800BC

700BCFinal Jomon pottery
Earliest stage of irrigated rice field
Spread of irrigated rice field
1100BC

1000BC

900BC

800BC700BC

Transition age of one pottery-type to another seems tocorrelate with climatic changes estimated from 14C records.

Variations of atmospheric 14C production rates in the past 3500 years

１４

C production rate（２nd millennium=１）

1.40

INTCAL98

1.30

Akita Chokai, Japanese cedar

1.20
1.10
1.00
0.90
0.80
0.70
0.60
0.50
-1500

-1000

-500

BC/AD

500

Cal Year（-BC/+AD）

1000

1500

Spread of wet-rice cultivation in East Asia
and Japanese archipelago
Sunazawa(砂沢)site
End of 5c.～early 4c.
Taruyanagi(垂柳)site
3rd c.

In 5th~ 4th c.BC and 3rd c. BC,
Aomori was warm enough to produce rice.
Sunazawa site (~400 BC) and Taruyanagi site (3rd c.BC)

Rice fields excavated（津軽平野・田舎館村で発見された弥生中期の水田跡)

Sunazawa

Taruyanagi

Variations of atmospheric 14 C production rate (relative to 100-y running av.）
0.7P(14C)

0.8
0.9
1
1.1
1.2

Temp anomaly（℃)

1.3
0.8

Temperature anomaly in Yamal Peninsula (based on tree-ring）

0.4
0-0.4-0.8-500-400-300-200-100

BC/AD

100

200

300

400

Cal Year（-BC/+AD)

Yamal Peninsula (North-west Siberia) data of lower figure are from Hantemirov,
R.M. and S.G. Shiyatov, 2002500

High P(14C)

倭国大乱; extended war
in western Honshu is.

Rainfall/Humidity in late Yayoi period (Kiso , centralJapan) (from T. Nakatuka,2010)

TemperatureAnomaly(.℃）

21.5
10.5
0-0.5
-1-1.5-2

Beijing Summer Temperature Record from Stalagmite (Tan et al, 2003)

High P(14C)150
Regional Offset
14（ C-years)

Regional Offset in Japanese Tree-rings
100500-50300BC

200BC

100BC

BC/AD

100AD

200AD

300AD

400AD

Callendar Age

倭国大乱
Beijing summer temperature/precipitation proxy records (Tan et al.2003,upper) compared with the regional offsets measured for Japanese cedars
and cypress

400

Effect of huge volcanic Eruptions
350

Sulfate Ion(ppb)

300
250
200
150
100
500-500 -300 -100

100

300

500

700

900

1100 1300 1500 1700 1900

Year (-BC/+AD)
From Zielinski G.A. et al. 1994, Record of volcanism since 7000 B.C. from GISP GreenlandIce Core and implications for the volcano-climate system, Science 264, pp. 948-952

Summary• High summer temperature periods in East Asia for the last2000 years coincide in most cases with the high solar
activity periods estimated from variations of 14C
production rates.
• EL Nino and La Nina tend to occur in low solar magnetic
activity, suggesting more stable climates in the high solar
activity periods than in the low solar activity periods.
• Japanese tree-rings for the periods particularly in 1c.
AD~2nd c. AD show deviations (offsets) in 14C from INTCAL.
• Synchronous behavior of time series for Beijing warm time
climate proxies from stalagmites and 14C offsets in theJapanese tree-rings strongly suggests the effect of Eat
Asian summer monsoon in these periods.
• Timing of wet-rice cultivation introduced to Japanesearchipelago in 10~9c. BC and its spread to north in 5th c.
BC ~4th c. BC seem to correlate with the climatesestimated from 14C records.