GEOG3839.9: Climate from trees

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Scott St. George

Tree growth is correlated with climate factors like temperature and precipitation. By analyzing tree ring widths and comparing them to historical climate records, researchers have developed climate reconstructions extending back centuries. The technique involves cross-dating multiple tree ring records to find shared variance representing regional climate signals, then using regression models to estimate past climate values from that shared variance. When done properly across many tree ring sites, this allows empirical reconstruction of climate over periods without direct instrumental records.

Educación Tecnología Empresariales

temperature water day length

THE PRINCIPLE OF
CROSS-DATING
THE PRINCIPLE OF
AGGREGATE TREE GROWTH
THE PRINCIPLE OF
REPLICATION

STANDARDIZATION
THE PRINCIPLE OF
ECOLOGICAL AMPLITUDE
THE PRINCIPLE OF
SITE SELECTION

White pine 1714

Photograph: Kurt Kipfmueller

C L I M AT E F R O M T R E E S

Photograph: RawheaD Rex

empirical Information gained by means of
observation, experience or experiment.

Photograph: Minyoung Choi

h p://sokar.geo.umn.edu/weather/

Single-site reconstruction

A time series is a set of observations
ordered in time.

time span
resolution
10
last century
annual
5
PDSI

0
chronological uncertainty
-5 sub-annual
-10
1900 1920 1940 1960 1980 2000
Year (A.D.)

variance a statistical measure that describes how a
set of numbers vary around their mean.

The second moment of a distribution.

variance observation

sample
mean
sample
size

Variance

10

5
PDSI

0

-5

-10
1900 1920 1940 1960 1980 2000
Year (A.D.)

empirical comparisons

thermometers

tree rings

Source: Hughes et al., 1999

rain gauges

tree rings

Source: Hughes and Funkhouser, 1998

correlation The Pearson product-moment
correlation coeﬃcient is probably the single
most widely used statistic for summarizing
the relationship between two variables.

covariance

product of both standard deviations

Correlation Pearson’s product-moment correlation

variable ‘Y’
r = +1.0

variable ‘X’

variable ‘Y’
r = -1.0

variable ‘X’

variable ‘Y’
r = +0.85

variable ‘X’

Ring-width
index

“SHARED”
VARIANCE

10 3

2
5

Ringwidth
1
PDSI

0 0

-1
-5
-2

-10 -3
1900 1920 1940 1960 1980 2000
Year (A.D.)
St. George et al., (2009), Journal of Climate

r = 0.62
r2 = 0.62 2

r2 = 0.38

38% shared variance
10 3

2
5

Ringwidth
1
PDSI

0 0

-1
-5
-2

-10 -3
1900 1920 1940 1960 1980 2000
Year (A.D.)
St. George et al., (2009), Journal of Climate

covariance

product of both standard deviations

Correlation Pearson’s product-moment correlation

r = 0.816

Source: Wikipedia

Single-site reconstruction

CORRELATION
FUNCTION

Source: Kipfmueller, 2008

LINEAR
REGRESSION

yt = axt + b + ε

the climate variable
of interest (at year t)

yt = axt + b + ε

yt = axt + b + ε

the tree-ring
variable (at year t)

regression weight
for the tree-ring
variable

yt = axt + b + ε

constant

yt = axt + b + ε

yt = axt + b + ε
error of the residual

yt = axt + b + ε

Ring-width
index

CLIMATE
RECONSTRUCTION

never trust
one tree

Multiple-site reconstruction

‘multiple’ linear regresson

yt = a1x1t + a2x2t + a3x3t ... + b + ε

Network reconstruction

yt = axt + b + ε

average tree-ring
width at many sites
(in year t)

‘SHARED’ VARIANCE

CORRELATION FUNCTION

LINEAR REGRESSION

CLIMATE RECONSTRUCTION

Tree rings can provide extra-ordinarily good estimates (sometimes)

Source: Woodhouse et al., 2006

White pine 1714

Photograph: Kurt Kipfmueller

GEOG3839.9: Climate from trees

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Klinik_ Apotek Onlin 085657271886 Solusi Menggugurkan Masalah Kehamilan Anda Jual Obat Aborsi Asli KLINIK ABORSI TERPEECAYA _ Jual Obat Aborsi Cytotec Misoprostol Asli 100% Ampuh Hanya 3 Jam Langsung Gugur || OBAT PENGGUGUR KANDUNGAN AMPUH MANJUR OBAT ABORSI OLINE" APOTIK Jual Obat Cytotec, Gastrul, Gynecoside Asli Ampuh. JUAL ” Obat Aborsi Tuntas | Obat Aborsi Manjur | Obat Aborsi Ampuh | Obat Penggugur Janin | Obat Pencegah Kehamilan | Obat Pelancar Haid | Obat terlambat Bulan | Ciri Obat Aborsi Asli | Obat Telat Bulan | Pil Aborsi Asli | Cara Menggugurkan Konten | Cara Aborsi Tuntas | Harga Obat Aborsi Asli | Pil Aborsi | Jual Obat Aborsi Cytotec | Cara Aborsi Sendiri | Cara Aborsi Usia 1 Bulan | Cara Aborsi Usia 2 Tahun | Cara Aborsi Usia 3 Bulan | Obat Aborsi Usia 4 Bulan | Cara Abrasi Usia 5 Bulan | Cara Menggugurkan Konten | Kandungan Obat Penggugur | Cara Menghitung Usia Konten | Cara Mengatasi Terlambat Bulan | Penjual Obat Aborsi Asli | Obat Aborsi Garansi | Kandungan Obat Peluntur | Obat Telat Datang Bulan | Obat Telat Haid | Obat Aborsi Paling Murah | Klinik Jual Obat Aborsi | Jual Pil Cytotec | Apotik Jual Obat Aborsi | Kandungan Dokter Abrasi | Cara Aborsi Cepat | Jual Obat Aborsi Bergaransi | Jual Obat Cytotec Asli | Obat Aborsi Aman Manjur | Obat Misoprostol Cytotec Asli. "APA ITU ABORSI" “Aborsi Adalah dengan membendung hormon yang di perlukan untuk mempertahankan kehamilan yaitu hormon progesteron, karena hormon ini dibendung, maka jalur kehamilan mulai membuka dan leher rahim menjadi melunak,sehingga mengeluarkan darah yang merupakan tanda bahwa obat telah bekerja || maksimal 1 jam obat diminum || PENJELASAN OBAT ABORSI USIA 1 _7 BULAN Pada usia kandungan ini, pasien akan merasakan sakit yang sedikit tidak berlebihan || sekitar 1 jam ||. namun hanya akan terjadi pada saatdarah keluar merupakan pertanda menstruasi. Hal ini dikarenakan pada usiakandungan 3 bulan,janin sudah terbentuk sebesar kepalan tangan orang dewasa. Cara kerja obat aborsi : JUAL OBAT ABORSI AMPUH dosis 3 bulan secara umum sama dengan cara kerja || DOSIS OBAT ABORSI 2 bulan”, hanya berbedanya selain mengisolasijanin juga menghancurkan janin dengan formula methotrexate dikandungdidalamnya. Formula methotrexate ini sangat ampuh untuk menghancurkan janinmenjadi serpihan-serpihan kecil akan sangat berguna pada saat dikeluarkan nanti. APA ALASAN WANITA MELAKUKAN ABORSI? Aborsi di lakukan wanita hamil baik yang sudah menikah maupun belum menikah dengan berbagai alasan , akan tetapi alasan yang utama adalah alasan-alasan non medis (termasuk aborsi sendiri / di sengaja/ buatan] MELAYANI PEMESANAN OBAT ABORSI SETIAP HARI, SIAP KIRIM KESELURUH KOTA BESAR DI INDONESIA DAN LUAR NEGERI. HUBUNGI PEMESANAN LEBIH NYAMAN VIA WA/: 085657271886

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GEOG3839.9: Climate from trees

1.

2.

3. temperature water day length

4. THE PRINCIPLE OF CROSS-DATING THE PRINCIPLE OF AGGREGATE TREE GROWTH THE PRINCIPLE OF REPLICATION STANDARDIZATION THE PRINCIPLE OF ECOLOGICAL AMPLITUDE THE PRINCIPLE OF SITE SELECTION

5. White pine 1714 Photograph: Kurt Kipfmueller

6. C L I M AT E F R O M T R E E S Photograph: RawheaD Rex

7. empirical Information gained by means of observation, experience or experiment.

8.

9. Photograph: Minyoung Choi

10. h p://sokar.geo.umn.edu/weather/

11. Single-site reconstruction

12. A time series is a set of observations ordered in time.

13. time span resolution 10 last century annual 5 PDSI 0 chronological uncertainty -5 sub-annual -10 1900 1920 1940 1960 1980 2000 Year (A.D.)

14. variance a statistical measure that describes how a set of numbers vary around their mean. The second moment of a distribution.

15. variance observation sample mean sample size Variance

16. 10 5 PDSI 0 -5 -10 1900 1920 1940 1960 1980 2000 Year (A.D.)

17. empirical comparisons

18. thermometers tree rings Source: Hughes et al., 1999

19. rain gauges tree rings Source: Hughes and Funkhouser, 1998

20. correlation The Pearson product-moment correlation coeﬃcient is probably the single most widely used statistic for summarizing the relationship between two variables.

21. covariance product of both standard deviations Correlation Pearson’s product-moment correlation

22. variable ‘Y’ r = +1.0 variable ‘X’

23. variable ‘Y’ r = -1.0 variable ‘X’

24. variable ‘Y’ r = +0.85 variable ‘X’

25. Ring-width index

26. “SHARED” VARIANCE

27. 10 3 2 5 Ringwidth 1 PDSI 0 0 -1 -5 -2 -10 -3 1900 1920 1940 1960 1980 2000 Year (A.D.) St. George et al., (2009), Journal of Climate

28. r = 0.62 r2 = 0.62 2 r2 = 0.38

29. 38% shared variance 10 3 2 5 Ringwidth 1 PDSI 0 0 -1 -5 -2 -10 -3 1900 1920 1940 1960 1980 2000 Year (A.D.) St. George et al., (2009), Journal of Climate

30. covariance product of both standard deviations Correlation Pearson’s product-moment correlation

31. r = 0.816 Source: Wikipedia

32. Single-site reconstruction

33. CORRELATION FUNCTION

34. Source: Kipfmueller, 2008

35. LINEAR REGRESSION

36. yt = axt + b + ε

37. the climate variable of interest (at year t) yt = axt + b + ε

38. yt = axt + b + ε the tree-ring variable (at year t)

39. regression weight for the tree-ring variable yt = axt + b + ε

40. constant yt = axt + b + ε

41. yt = axt + b + ε error of the residual

42. yt = axt + b + ε

43. Ring-width index

44. CLIMATE RECONSTRUCTION

45.

46. never trust one tree

47. Multiple-site reconstruction

48. ‘multiple’ linear regresson yt = a1x1t + a2x2t + a3x3t ... + b + ε

49. Network reconstruction

50. yt = axt + b + ε average tree-ring width at many sites (in year t)

51. ‘SHARED’ VARIANCE CORRELATION FUNCTION LINEAR REGRESSION CLIMATE RECONSTRUCTION

52. Tree rings can provide extra-ordinarily good estimates (sometimes) Source: Woodhouse et al., 2006

53. White pine 1714 Photograph: Kurt Kipfmueller