what can be learnt from oxygen isotopes composition of teak tree rings from india? rainfall...
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What can be learnt from oxygen isotopes composition of teak tree rings from India?
Rainfall reconstruction up to AD 1743.
Shreyas R. Managave
Department of Earth SciencesPondicherry University, India
CollaboratorsProf. R. Ramesh, Physical Research Laboratory, Ahmedabad, India
Dr. H. P. Borgaonkar, Indian Institute of Tropical Meteorology, Pune, IndiaDr. A. Bhattacharyya, Birbal Sahani Institute of Palaeobotany, Lucknow, India
Teak (Tectona grandis)
Chhattisgarh I Chhattisgarh II Kerala
Jagadalpur
Hanamkonda
Perambikulum
Sample Locations
(1532 mm; 82 days, NE/SW=0.11)
(940 mm, 53 days, NE/SW=0.17)
(2163 mm, 102 days, NE/SW=0.27)
Objectives
To understand what governs isotopic composition of teak growing in different meteorological settings in India
To check whether trees growing in the southern part of India show isotopic signature of SW and
NE monsoons
Reconstruction of high resolution past monsoon rainfall
Rationale behind the data interpretation
Amount effect and passage of water in plant
d18Orain Amount of rainfall
1
Precipitation
H2O
CO2
Importance of relative humidity
1816
16
16
1616
Relatively 16O enriched
Relatively 18O enriched
6CO2 + 6H2O + sunlight = C6H12O6 + 6O2
Results from intra-ring studies
Results from inter-ring studies
Results from intra-ring studies
1 ~ Early growing season (May)2-6 ~ Main growing season (June-Sept)7-8 ~ Late growing season (Oct-Dec)
Pit
h s
ide B
ark side
1 2 34 5 6
7 8
time
Tree from central India & southern India
Percent distance from the pith side
0 25 50 75 100
-c
ell
ulo
se 1
8 O
23
24
25
26
27
28
29
30
1995 19721971197019691963183918341833
Intra-ring d18O analysis of teak sample from central India
Percent distance from the pith side
0 25 50 75 100
-c
ell
ulo
se 1
8 O
22.0
24.0
26.0
28.0
30.0
32.0
1985 (6-parts)1977 (6-parts)1970 (12-parts)1971 (16-parts)
Coarse resolution studies High resolution studies
June to Sept June to SeptOct-Dec Oct-Dec
Pith side
Bark side
4mmtime
Sample location: Jagdalpur
Managave et al., GRL 2010
IN D IA
M um ba i
Thane
H yderabad
S a lag iriJagdalpur
K ozh ikodeP a lakkad
H anam kondaAP
0 200 400
km
Perambikulam10 0 N
20 0 N
10 0 N
15 0 N
20 0 N
80 0 E 85 0 E
70 0 E 80 0 E 85 0 E
15 0 N
75 0 E70 0 E
75 0 E
-c
ellu
lose
18
O
22
24
26
28
30
32
-c
ellu
lose
18
O
22
24
26
28
30
32
1995 19721971197019691963184818441843
Jagdalpur (Jag03)
Percent distance from the pith side
0 25 50 75 100
-c
ellu
lose
18
O
22
24
26
28
30
32
Hanamkonda (AP1)
18921886188218811878
19641956
19691979 1925
190919051895
Jagdalpur (Jag04)
a)
b)
c)
Managave et al., GRL 2010
22 24 26 28 30 3260
64
68
72
76
76
78
80
82
84
86
Cellulose O (‰)
R = -0.54P<0.015
(e)
R = -0.57P<0.08
(f)
RH
(%)
40
45
50
55
60
65
70
R = -0.62P<0.058
(d)
- Jag04- Jag03
Percent distance from the pith side
0 25 50 75 100
Cel
lulo
se
O
22
24
26
28
30
32
Cel
lulo
se
O
22
24
26
28
30
32
22
24
26
28
30
32
Jagdalpur (Jag03)
Jagdalpur (Jag04)
Hanamkonda (AP1)
My June July Aug Sept Oct DcNv
18921886188218811878
1925190919051895
19641956
19691979
184818441843
1995 19721971197019691963
Cel
lulo
se
O
(a)
(b)
(c)
Relative humidity controls intra-annual d18O variations
26 28 30 32R
H (
%)
40
50
60
70
22 24 26 28 30 3276
80
84
88
24 26 28 30 3260
64
68
72
76
22 24 26 28 30 3278
80
82
84
86
22 24 26 28 30 3240
50
60
70
80
90
23 24 25 26 27 28 29 30 3176
78
80
82
84
86
Cellulose O (‰)
R = -0.58P<0.0001
R = -0.54P<0.015
R = -0.62P<0.058
R = -0.76P<0.01
R = -0.38P<0.28
R = -0.57P<0.08
(a) (b)
(c) (d)
(e) (f)
- Jag03 - Jag04
26 28 30 32
RH
(%
)
40
50
60
70
22 24 26 28 30 32
76
80
84
88
24 26 28 30 32
60
64
68
72
76
22 24 26 28 30 32
78
80
82
84
86
22 24 26 28 30 32
40
50
60
70
80
90
23 24 25 26 27 28 29 30 31
76
78
80
82
84
86
Cellulose O (‰)
R = -0.58P<0.0001
R = -0.54P<0.015
R = -0.62P<0.058
R = -0.76P<0.01
R = -0.38P<0.28
R = -0.57P<0.08
(a) (b)
(c) (d)
(e) (f)
- Jag03 - Jag04
Managave et al., GRL 2010
Break monsoons and intra-ring d18O variations
3 to 17 days (average 5.8 days) (Ramamurthy, 1969)
Goswami and Mohan, 2001; Gadgil and Joseph 2003
Break monsoons and relative humidity
Rainfall Relative humidity
(Krishnamurthy and Biswas, 2006)
Break monsoon over central India
Break monsoons and relative humidity
22 24 26 28 30 3260
64
68
72
76
76
78
80
82
84
86
Cellulose O (‰)
R = -0.54P<0.015
(e)
R = -0.57P<0.08
(f)
RH
(%
)
40
45
50
55
60
65
70
R = -0.62P<0.058
(d)
- Jag04- Jag03
Percent distance from the pith side
0 25 50 75 100
Ce
llu
los
e
O
22
24
26
28
30
32
Ce
llu
los
e
O
22
24
26
28
30
32
22
24
26
28
30
32
Jagdalpur (Jag03)
Jagdalpur (Jag04)
Hanamkonda (AP1)
My June July Aug Sept Oct DcNv
18921886188218811878
1925190919051895
19641956
19691979
184818441843
1995 19721971197019691963
Ce
llu
los
e
O
(a)
(b)
(c)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
(a) (b)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
(a) (b)
Year with break-monsoon(19th July to 3rd Aug 1972 A.D.)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
(a) (b)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
Year with active monsoon (1st Aug to 31st Sept 1971 A.D.)
Year with break-monsoon (19th July to 3rd Aug 1972 A.D.)
(a) (b)
Year with active monsoon(1st Aug to 31st Sept 1971 A.D.)
Managave et al., GRL 2010
13C
-29 -28 -27 -26 -25 -24 -23
18O
22
24
26
28
30
32
Location: Jagadalpur, Chattisgarh
Intra-annual carbon and oxygen isotopic composition of teak
Positive correlation indicates control of relative humidity
Intra-annual d18O variations
Location: Perambikulum, south India
c
ellu
los
e1
8 O
25.0
26.0
27.0
28.0
29.0
30.0 Q RSP
0 25 50 75 100
-c
ellu
los
e 1
8O
25.0
26.0
27.0
28.0
29.0
30.0
Percent distance from pith side
# 217(6-parts)# 219 (6-parts)# 220 (6-parts)
# 226 (6-parts)# 235 (6-parts)# 237 (8-parts)
(b)
# 207# 208
# 217# 218# 228# 235# 237
# 164# 178# 179# 192# 195# 196# 204
(a)
June to Sept Oct-Dec
Percent distance from the pith side
0 25 50 75 100
-c
ellu
lose
18
O
22.0
24.0
26.0
28.0
30.0
32.0
1985 (6-parts)1977 (6-parts)1970 (12-parts)1971 (16-parts)
Location: Jagadalpur, central India
Percent distance from the pith side
0 25 50 75 100
-c
ell
ulo
se
1
8 O
23
24
25
26
27
28
29
30
1995 19721971197019691963183918341833
June to Sept Oct-Dec
Managave et al., Clim dyn 2011
Winter (NE) monsoon rain is depleted in 18O
Location: KozhikodeGNIP data
Modeled climatological d18O profiles for Palakkad area
May Jun Jul Aug Sep Oct Nov Dec
Prec
ipita
tion
(mm
)
0
200
400
600
800
60
70
80
90
18O
rain
-8
-6
-4
-2
-2
0
2
4
6
Rel
ativ
e
18O
Relative H
umidity (%
)
-2
0
2
4
6
Modelled 18O cellulose considering monthly 18O of rain
Modelled 18O cellulose considering constant 18O of rain
(a)
(b)
(c)
Relative
18O
Rain 18O Precipitation Relative humidity
Trees from southern India samples both the SW (Jun-Sept) and NE (Oct-Dec) monsoons
d18O of whole ring is likely affected by (NE/SW) ratio
Monthly weather data Palakkad (Rainfall, RH)
(1950-1980);& Kozhikode (d18O)
(1996-2001)
Climatological intra-ringd18O profiles
Managave et al., Clim dyn 2011
Significance of plants having signature of both the monsoons
Spatial distribution of (d18Osummer – d18Owinter) rainfall
Araguas-Araguas et al., 1998
Summary of intra-ring studies Teak from central India:
Relative humidity decides intra-ringd18O variations Time resolution: pre-, main- and post-monsoonPossibility of detecting major break-monsoons
Teak from southern India: Winter monsoon signature is preserved Possibility of reconstructed both the monsoons
using intra-ring studies Care should be taken while interpreting annual d18O variations
Results from inter-ring studies
a) Tree from Jagadalpur, central India
b) Tree from Perambikulum, southern India
Location: Jagadalpur, central India
7000
9000
11000
13000
15000
17000
19000
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
24.0
25.0
26.0
27.0
28.0
29.0
30.0
Rainfall
Cellulose d18O
Sub-
divi
sion
al ra
infa
lld
18O
(r = 0.5, P<0.005)
Positive correlation between rainfall & d18O
Managave et al., Dendrochronologia, 2011
Why positive correlation between cell. d18O and rainfall?
Leaf areaindex
Leaf areaindex
Soil moisture
Soil moisture
Yoshifuji et al., 2003 data
Higher the length of growing season, more positive d18O values
Relative humidity conditions during monsoon and post-monsoon season
Lower d18O Higher d18O
20.0
22.0
24.0
26.0
28.0
30.0
32.0
1855 1875 1895 1915 1935 1955 1975 1995
Year AD
18 O
23.0
25.0
27.0
29.0
31.0
33.0
18 O
Location: Jagadalpur, Chattisgarh
5-yr running mean
Comparison between two trees from Jagadalpur
r=0.5 P<0.005r=0.7 P<0.005
Managave et al., Dndrochronologia, 2011
Location: Perambikulum Kerala
Negative correlation between rainfall & d18O
r = −0.5, p<0.005
Managave et al., Dndrochronologia, 2011
Temporally varying strength of correlation
Managave et al., Dndrochronologia, 2011
Higher rainfall during the later part of the Little Ice Age
Comparison with regional rainfall record
Extended local and regional rainfall record by 128 and 70 years, respectively
Managave et al., Dndrochronologia, 2011
Thank you
Other evidences of higher rainfall
Borgaonkar et al., 2007
Bhattacharyya et al., 2007
-8.4
-7.8
-7.2
-6.6
-6.0
-30
-28
-26
-24
-22
Mean of intra-annual C values
C of atmospheric CO2
1
3CC
O2
Year (A.D.)
1750 1800 1850 1900 1950 2000
C
teak
-30
-28
-26
-24
-22
-8.4
-7.8
-7.2
-6.6
-6.0
13C
-29 -28 -27 -26 -25 -24 -23
18O
22
24
26
28
30
32
Observed and modeled Intra-ring d18O variations
Models can be used to interpret intra-ring d18O variations
Resolution of main- and post-monsoon season can be achieved
Possibility of achieving ~20 days of time resolution
0 20 40 60 80 100
Rel
ativ
e 1
8O
0
4
8
12
Prec
ipita
tion
(mm
)
0
40
80 R H
(%)
40
80
Relative
18O
0
4
8
12
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
??
(a)
(c)
(b)
Percent distance from the pith side
Jagdalpur sampleObserved
Ring = 1971
Modeled
Daily weather, 1971,Jagadalpur
Under review: Current Science
1920
1922
1924
1926
1928
1930
1932
1934
1936
1938
1940
1942
1944
1946
1948
1950
1952
1954
1956
1958
1960
1962
%d
epar
ture
an
amo
ly
-40
-30
-20
-10
0
10
20
30
40
50
60
24
26
28
30
32
34
36%departure anamoly 18O
No amount effect By and large positive correlation between rainfall & d18O
(r = 0.4, P<0.005)
% r
ain
fall
dep
artu
re
ano
mal
y
d18O
Location: Thane, western India
Under review: Dendrochronologia