large-scale dendrochronology and low-frequency climate variability
TRANSCRIPT
![Page 1: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/1.jpg)
LARGE-SCALE DENDROCHRONOLOGY AND LOW-FREQUENCY CLIMATE VARIABILITY
KlimaCampus Colloquium, University of Hamburg | July 9 2015
Sco! St. George University of Minnesota
![Page 2: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/2.jpg)
![Page 3: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/3.jpg)
![Page 4: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/4.jpg)
DECADAL VARIABILITY
![Page 5: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/5.jpg)
Source: Mohino et al., Climate Dynamics, 2011
SAHEL PRECIPITATION ANOMALIES (FILTERED TO EMPHASIZE LOW-FREQUENCY VARIABILITY)
![Page 6: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/6.jpg)
PACIFIC DECADAL
OSCILLATION
![Page 7: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/7.jpg)
1900 1920 1940 1960 1980 2000 2020
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000discharge (cfs) at Grand Forks, North Dakota
Source: United States Geological Survey
THE RED RIVER OF THE NORTH, LEAST STATIONARY RIVER IN THE USA
![Page 8: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/8.jpg)
DECADAL PREDICTION, A NEW FIELD OF STUDY,
FOCUSES ON TIME-EVOLVING REGIONAL CLIMATE CONDITIONS
OVER THE NEXT 10-30 YR, WHICH IS A TIME PERIOD OF INTEREST
TO INFRASTRUCTURE PLANNERS, WATER RESOURCES MANAGERS, AND OTHERS.
“ ”
Meehl et al., 2009 Bulletin of the American Meteorological Society
![Page 9: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/9.jpg)
INSTRUMENTAL CLIMATE OBSERVATIONS
![Page 10: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/10.jpg)
-34°CFORT SNELLING, MINNESOTA
30.1.1820
![Page 11: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/11.jpg)
1900 1920 1940 1960 1980 2000 2020-4
-3
-2
-1
0
1
2
3
4
Source: Dr. Nate Mantua, University of Washington
LOW-FREQUENCY VARIABILITY IN THE NORTH PACIFIC AS REPRESENTED BY THE PACIFIC DECADAL OSCILLATION INDEX
![Page 12: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/12.jpg)
A LIMITATION OF THE INSTRUMENTAL RECORD
IS THAT IT SPANS AT MOST
A FEW REALIZATIONS OF DECADAL VARIABILITY.
“ ”Solomon et al., 2011
Bulletin of the American Meteorological Society
![Page 13: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/13.jpg)
Source: Deser et al., Annual Review of Marine Science, 2010
DISTRIBUTION OF SEA-SURFACE TEMPERATURE OBSERVATIONS FROM THE INTERNATIONAL COMPREHENSIVE
OCEAN ATMOSPHERE DATA SET
Percentage of months with at least one measurement
![Page 14: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/14.jpg)
MODEL SIMULATIONS
![Page 15: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/15.jpg)
![Page 16: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/16.jpg)
Source: Delworth and Zeng, Geophysical Research Le!ers, 2012
INVESTIGATING DECADAL TO MULTICENTENNIAL VARIABILITY OF NORTHERN HEMISPHERE SURFACE AIR TEMPERATURES
IN A 4000-YR CONTROL SIMULATION
![Page 17: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/17.jpg)
IN CCSM4, CENTENNIAL VARIABILITY ARISES PRIMARILY AS A THERMODYNAMIC RESPONSE TO EXPLOSIVE VOLCANISM.
Source: Ault et al., Geophysical Research Le!ers, 2013
![Page 18: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/18.jpg)
… THE USE OF HIGH-RESOLUTION PROXY DATA
SHOULD BE EXPANDED BECAUSE THE SHORT OBSERVATIONAL RECORD
AND MODEL UNCERTAINTY ARE UNABLE TO SIMULATE
[DECADAL CLIMATE VARIABILITY]…
“ ”
Mehta et al., 2011 Bulletin of the American Meteorological Society
![Page 19: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/19.jpg)
![Page 20: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/20.jpg)
Because temperate and boreal forests are so extensive, trees that form annual rings are very common.
Trees routinely a!ain ages in excess of several hundred years.
ADVANTAGES OF TREE-RING WIDTHSAS CLIMATE PROXIES
Source: St. George, Quaternary Science Reviews, 2014
Tree-ring records have annual resolution and the accuracy of their dating is confirmed by a rigorous cross-comparison procedure.
![Page 21: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/21.jpg)
Tree-ring display at elementary school
Photograph: Tom Swetnam
![Page 22: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/22.jpg)
Dr. David Meko University of Arizona
![Page 23: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/23.jpg)
Source: Meko et al., Geophysical Research Le!ers, 2007
MULTI-CENTURY RECONSTRUCTIONS OF COLORADO RIVER FLOW FROM TREE-RING WIDTHS
![Page 24: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/24.jpg)
PROXY ARCHIVES
![Page 25: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/25.jpg)
![Page 26: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/26.jpg)
… PRECIPITATION RECONSTRUCTIONS THAT ARE ENTIRELY BASED ON
TREE-RING WIDTH CHRONOLOGIES MAY CONSIDERABLY OVERESTIMATE
THE TRUE PERSISTENCE OF REGIONAL RAINFALL REGIMES.
“ ”Bunde et al., 2013
Nature Climate Change
![Page 27: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/27.jpg)
![Page 28: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/28.jpg)
THESE LARGE VALUES OF SERIAL CORRELATION SUGGEST THAT THE NON-RANDOMNESS
OF TREE-RING SEQUENCES IS DUE TO THE STORAGE OF FOOD PRODUCTS IN THE TREE
RATHER THAN THE YEAR TO YEAR VARIATIONS OF RAINFALL OR SOIL MOISTURE.
“ ”
Matalas, 1962 International Association of Scientific Hydrology. Bulletin
![Page 29: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/29.jpg)
ADVANTAGE
DISADVANTAGE Short relative to decadal timescales
Firmly grounded in reality
Too sensitive to volcanic forcing?
Simulations are much longer than the timescale of interest
Long records grounded in reality
Proxy systems may distort or exaggerate decadal signals
THE DECADAL CLIMATE “CONUNDRUM”
![Page 30: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/30.jpg)
Dr. Toby Ault Cornell University
![Page 31: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/31.jpg)
1DECVAR ALONG THE CENTRAL PACIFIC COAST
![Page 32: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/32.jpg)
2THE FIDELITY OF PALEO-PDO ESTIMATES
![Page 33: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/33.jpg)
3STRATEGIES TO TRACK PALEO-DECVAR
![Page 34: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/34.jpg)
![Page 35: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/35.jpg)
RINGS IN THE BRANCHES OF SAWED TREES SHOW
THE NUMBER OF YEARS AND, ACCORDING TO THEIR
THICKNESS, THE YEARS WHICH WERE
MORE OR LESS DRY.
“ ”
Leonardo da Vinci
![Page 36: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/36.jpg)
36
EARLYWOOD
LATEWOOD
ONE GROWTH RING
![Page 37: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/37.jpg)
HOW MANY (COMPLETE) TREE RINGS
ARE VISIBLE IN THIS MICROPHOTOGRAPH?
![Page 38: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/38.jpg)
![Page 39: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/39.jpg)
HOW MANY (COMPLETE) TREE RINGS
ARE VISIBLE IN THIS MICROPHOTOGRAPH?
![Page 40: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/40.jpg)
1871 1872 1873 1874
Source: Dr. Dan Griffin, University of Minnesota
![Page 41: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/41.jpg)
Source: Dr. Dan Griffin, University of Minnesota
NORTHWESTERN NEW MEXICO
![Page 42: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/42.jpg)
CRATER LAKE NATIONAL PARK
![Page 43: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/43.jpg)
1809 1811 181218081807
Source: Sarah Appleton, University of Minnesota
![Page 44: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/44.jpg)
![Page 45: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/45.jpg)
![Page 46: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/46.jpg)
IF NO RING WAS FORMED IN A GIVEN YEAR THAT CREATES A FURTHER COMPLICATION
INTRODUCING AN ERROR IN THE CHRONOLOGY ESTABLISHED BY
COUNTING RINGS BACK IN TIME.
“ ”
Dr. Michael Mann Penn State News, February 6. 2012
![Page 47: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/47.jpg)
Source: Esper et al., Dendrochronologia, 2013
If tree-ring records from Europe are shi#ed back one year, their strong correlation with long temperature records disappears.
![Page 48: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/48.jpg)
0% 2% 4% 6% 8%
20°N
40°N
60°N
80°N
Latit
ude
Percentage of locally-absent rings
0% 2% 4% 6% 8%
b
a
Picea Quercus
Pinus Pseudotsuga
Larix Other genera
1500
1000
500
0
# re
cord
s
Source: St. George et al., Geophysical Research Le!ers, 2013
![Page 49: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/49.jpg)
![Page 50: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/50.jpg)
Source: Büntgen et al., Nature Climate Change, 2014
Radiocarbon measurements of a subfossil pine (Pinus cembra) show the same 1.2% increase in 14C from AD 774 to 775.
![Page 51: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/51.jpg)
±0
![Page 52: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/52.jpg)
1DECVAR ALONG THE CENTRAL PACIFIC COAST
![Page 53: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/53.jpg)
Source: Dr. Greg Brooks, Geological Survey of Canada
RED RIVER, CENTRAL CANADA
![Page 54: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/54.jpg)
Source: Flickr user kc7cbf
![Page 55: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/55.jpg)
‘WHITE’total annual precipitation (mm)
ANNUAL PRECIPITATION IN DES MOINES, IOWA
Source: Global Historical Climate Network
![Page 56: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/56.jpg)
Central Pacific Coast
![Page 57: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/57.jpg)
1920 1960 2000
−400
0
400Regional winter precipitation anomalies (mm)
Ault and St. George, Journal of Climate, 2010
CENTRAL PACIFIC COAST
![Page 58: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/58.jpg)
1920 1960 2000
−400
0
400Regional winter precipitation anomalies (mm)
Ault and St. George, Journal of Climate, 2010
CENTRAL PACIFIC COAST
![Page 59: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/59.jpg)
THE HISTORY OF METEOROLOGY IS LITTERED WITH
THE WHITENED BONES OF CLAIMS TO HAVE DEMONSTRATED
THE EXISTENCE OF RELIABLE CYCLES IN THE WEATHER.
“ ”
William James Burroughs Weather Cycles: Real or Imaginary?
![Page 60: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/60.jpg)
![Page 61: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/61.jpg)
Source: California Department of Water Resources
Florsheim, JL, De!inger, MD, 2007. Climate and floods still govern California levee breaks.
Geophysical Research Le!ers.
![Page 62: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/62.jpg)
Source: Ault and St. George, Journal of Climate, 2010
STRONG DECADAL VARIABILITY SYNCHRONIZES RAINFALL, STREAMFLOW, AND HAZARDS IN NORTHERN CALIFORNIA.
![Page 63: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/63.jpg)
A STRONG ATMOSPHERIC RIVERCAN TRANSPORT 7-15X
THE WATER IN THE MISSISSIPPI RIVER
![Page 64: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/64.jpg)
… IN TODAY’S EMBANKED SYSTEM, 81% OF LEVEE BREAKS ALONG CENTRAL VALLEY RIVERS
OCCURRED FLOODS GENERATED BY WINTERTIME [ATMOSPHERIC RIVERS]
WITH ONLY 15% OCCURRING DURING SNOWMELT FLOODS.
“ ”
Florsheim and De!inger, 2015 Geomorphic Approaches to Integrated Floodplain Management
of Lowland Fluvial Systems in North America and Europe,
![Page 65: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/65.jpg)
![Page 66: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/66.jpg)
UNDER THE ‘HASSELMANN’ PARADIGM, THE LOW-FREQUENCY COMPONENTS
ARE DRIVEN BY THE STOCHASTIC HIGHER-FREQUENCY ONES
AND ARE NOT PREDICTABLE.
daysTIMESCALE
VARIANCE
decades
high
low
months
![Page 67: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/67.jpg)
ARE TREE-RING WIDTH RECORDS
ABLE TO TRACK THIS PARTICULAR
NARROWBAND FEATURE?
![Page 68: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/68.jpg)
CRATER LAKE NATIONAL PARK
![Page 69: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/69.jpg)
(a) Winter precipitation
(b) Summer precipitation
(c) Summer temperature
-0.8 +0.8-0.6 -0.4 -0.2 +0.2 +0.4 +0.6
Source: St. George, Quaternary Science Reviews, 2014
WINTER PRECIPITATION
![Page 70: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/70.jpg)
Source: Dr. Dan Griffin, University of Minnesota
QUERCUS DOUGLASII
![Page 71: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/71.jpg)
1700 1750 1800 1850 1900 1950 2000
Tree growth (anomalies)
−0.4
0.4
0
1650
ring-width records
mean of set
Source: St. George and Ault, Journal of Geophysical Research - Atmospheres, 2011
TREE-RING WIDTH RECORDS FROM BLUE OAKS INDICATE THE 20TH CENTURY WAS UNUSUALLY DECADAL.
![Page 72: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/72.jpg)
Source: Dr. Kevin Anchukaitis, University of Arizona
✔
![Page 73: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/73.jpg)
days decadesmonths
UNDER THE ‘BJERKNES’ PARADIGM, THE LONGER TIMESCALES MODULATE THE SHORTER ONES
THROUGH OCEAN PROCESSES AND THEREFORE MAY BE PREDICTABLE.
TIMESCALE
VARIANCE
high
low
![Page 74: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/74.jpg)
Source: NASA
![Page 75: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/75.jpg)
2THE FIDELITY OF PALEO-PDO ESTIMATES
![Page 76: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/76.jpg)
![Page 77: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/77.jpg)
PEYTO LAKE, CANADA
![Page 78: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/78.jpg)
(a) Winter precipitation
(b) Summer precipitation
(c) Summer temperature
-0.8 +0.8-0.6 -0.4 -0.2 +0.2 +0.4 +0.6Source: St. George, Quaternary Science Reviews, 2014
SUMMER TEMPERATURE
![Page 79: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/79.jpg)
Source: Fri!s et al., Journal of Applied Meteorology, 1971
SEASONAL PRESSURE ANOMALIES OVER THE NORTH AMERICAN SECTOR RECONSTRUCTED FROM 49 RING-WIDTH RECORDS
![Page 80: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/80.jpg)
A LONG CLIMATIC RECORD CAN SERVE TO IDENTIFY
THE RANGE OF POSSIBLE CLIMATESAND THE CHARACTERISTICS OF
POSSIBLE CLIMATE “MODES”.
“ ”Fri!s et al., 1971
Journal of Applied Meteorology
![Page 81: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/81.jpg)
![Page 82: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/82.jpg)
(a) El Niño-Southern Oscillation
(b) Pacific Decadal Oscillation
(c) Atlantic Multidecadal Oscillation
-0.8 +0.8-0.6 -0.4 -0.2 +0.2 +0.4 +0.6
Source: St. George, Quaternary Science Reviews, 2014
ENSO
![Page 83: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/83.jpg)
PACIFIC DECADAL
OSCILLATION
![Page 84: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/84.jpg)
PDOD’ARRIGO AND WILSON, 2006
“ON THE ASIAN EXPRESSION OF THE PDO”
D’ARRIGO ET AL., 2001 “TREE-RING ESTIMATES OF
PACIFIC DECADAL CLIMATE VARIABILITY”
BIONDI ET AL., 2001 “NORTH PACIFIC DECADAL CLIMATE VARIABILITY
SINCE 1661”
GEDALOF AND SMITH, 2001 “INTERDECADAL CLIMATE VARIABILITY AND
REGIME-SCALE SHIFTS IN PACIFIC NORTH AMERICA”
MACDONALD AND CASE, 2005 “VARIATIONS IN THE PACIFIC DECADAL OSCILLATION
OF THE PAST MILLENNIUM”
![Page 85: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/85.jpg)
Source: Newman et al,, in revision
![Page 86: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/86.jpg)
![Page 87: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/87.jpg)
… DROUGHTS OCCURRED DURING PERIODS OF BOTH WARM AND COOL KUROSHIO EXTENSION SSTS
AND PERHAPS DURING POSITIVE AND NEGATIVE PDO,
ALTHOUGH THIS IS DEPENDENT ON WHICH PDO RECONSTRUCTION IS USED.
“ ”
McCabe-Glynn et al., 2013 Nature Geoscience
![Page 88: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/88.jpg)
Source: Newman et al,, in revision
POOR REPRODUCIBILITY BETWEEN VARIOUS PDO RECONSTRUCTIONS CALLS TO QUESTION THEIR COLLECTIVE FIDELITY.
![Page 89: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/89.jpg)
Source: Michael Chow
BOULDER, COLORADO
![Page 90: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/90.jpg)
Source: Kipfmueller et al., Geophysical Research Le!ers, 2012
BLACK : WARM PHASE WHITE: COLD PHASE
GREY: NO DATA
ANY CONCLUSION THAT EXTENSIVE WILDFIRES ARE MORE OR LESS COMMON WHEN THE PDO IS IN ONE PHASE OR THE OTHER
DEPENDS ENTIRELY ON THE CHOICE OF PDO RECONSTRUCTION.
![Page 91: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/91.jpg)
WHY HAS IT BEEN SUCH A CHALLENGE
TO RECONSTRUCT THIS ASPECT OF DECADAL VARIABILITY IN THE NORTH PACIFIC?
![Page 92: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/92.jpg)
![Page 93: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/93.jpg)
OCEAN SURFACE HEAT FLUX (VIA THE ALEUTIAN LOW)
OCEAN MEMORY
THE KUROSHIO-OYASHIO CURRENT
+
+
THE PDO =
Source: Newman et al,, in revision
![Page 94: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/94.jpg)
SMALL SETS OF TREE-RING WIDTH
DATA
LARGE-SCALE GEOPHYSICAL PHENOMENA
![Page 95: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/95.jpg)
(a) El Niño-Southern Oscillation
(b) Pacific Decadal Oscillation
(c) Atlantic Multidecadal Oscillation
-0.8 +0.8-0.6 -0.4 -0.2 +0.2 +0.4 +0.6
Source: St. George, Quaternary Science Reviews, 2014
PDO
![Page 96: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/96.jpg)
PinusPicea
QuercusPseudotsuga
Larix
NothofagusAustrocedrisPhyllocladus
Agathis
Source: St. George, PAGES Magazine, 2014
There are more than 3,200 publicly-available tree-ring records (and many more held by individual investigators).
![Page 97: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/97.jpg)
![Page 98: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/98.jpg)
![Page 99: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/99.jpg)
3STRATEGIES TO TRACK PALEO-DECVAR
![Page 100: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/100.jpg)
Source: Gray et al., Geophysical Research Le!ers, 2003
Most dendroclimatic studies first reconstruct an annually-resolved target variable, and then apply some form of filter to emphasize decadal behavior.
![Page 101: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/101.jpg)
IMPROVING ESTIMATES OF INTERMEDIATE-SCALE
VARIABILITY
![Page 102: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/102.jpg)
TREE-RING WIDTHS BECOME SMALLER AS THE TREE GETS OLDER
BECAUSE OF THE GEOMETRICAL CONSTRAINT CREATED BY ADDING A VOLUME OF WOOD
TO A STEM OF INCREASING RADIUS.
![Page 103: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/103.jpg)
[AGE-SIZE TRENDS IN TREE-RING WIDTH] SHOULD BE THOUGHT OF AS
A NONSTATIONARY, STOCHASTIC PROCESS THAT MAY, AS A SPECIAL CASE,
BE MODELED AS A DETERMINISTIC PROCESS.
“ ”Cook and Briffa, 1990
Methods of Dendrochronology
![Page 104: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/104.jpg)
(A) the ‘raw’ ring-width data
![Page 105: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/105.jpg)
(B) the ‘detrended’ ring-width
index
![Page 106: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/106.jpg)
THE MOST OBVIOUS SOURCE OF NONCLIMATIC PERSISTENCE
IN TREE-RING DATAIS ERROR IN REMOVAL OF
THE GROWTH TREND WHEN CONVERTING ANNUAL RING WIDTHS
TO TREE-RING INDICES.
“ ”
Meko, 1981 Doctoral dissertation, University of Arizona
![Page 107: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/107.jpg)
![Page 108: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/108.jpg)
![Page 109: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/109.jpg)
PRESERVING DECADAL VARIANCE IN DENDROCLIMATIC RECONSTRUCTIONS
![Page 110: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/110.jpg)
Dr. Toby Ault Cornell University
![Page 111: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/111.jpg)
CHRONOLOGY RECONSTRUCTIONmean-value function
representing annual tree growth across many dozens or hundreds of trees
quantitative estimate of a climate variable
derived from one or several tree-ring chronologies
![Page 112: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/112.jpg)
Source: Adapted from Ault et al., Journal of Climate, 2013
PALEO-PRECIPITATION RECONSTRUCTIONS FROM TREE RINGS HAVE LESS VARIANCE AT LOW FREQUENCIES
THAN THE ORIGINAL TREE-RING CHRONOLOGIES.
![Page 113: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/113.jpg)
Chronology ‘A’
Chronology ‘B’
Chronology ‘C’
Chronology ‘D’
Chronology ‘E’
Chronology ‘F’
Chronology ‘G’
Chronology ‘H’
Chronology ‘I’
Chronology ‘J’
Reconstruction10 predictors76421
THE NESTED RECONSTRUCTION APPROACH GENERATES A NEW MODEL FOR EACH SUBSET OF PREDICTORS.
![Page 114: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/114.jpg)
Source: Cook et al., Journal of Quaternary Sciences, 2010
THE NORTH AMERICAN DROUGHT ATLAS USES A NETWORK OF MOISTURE-SENSITIVE TREE-RING RECORDS TO ESTIMATE CHANGES IN DROUGHT CONDITIONS
ACROSS THE CONTINENT.
![Page 115: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/115.jpg)
450 km
A FIXED SEARCH RADIUS AROUND EACH GRID POINT DEFINES THE ZONE OF LOCAL CONTROL
EXERCISED BY THE METHOD IN SELECTING CANDIDATE TREE-RING PREDICTORS
OF PDSI.
Source: Cook et al., Journal of Climate, 1999
![Page 116: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/116.jpg)
CHOOSING ALTERNATIVE DECADAL TARGETS
FOR RECONSTRUCTION
![Page 117: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/117.jpg)
OCEAN SURFACE HEAT FLUX (VIA THE ALEUTIAN LOW)
OCEAN MEMORY
THE KUROSHIO-OYASHIO CURRENT
+
+
THE PDO =
Source: Newman et al,, in revision
![Page 118: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/118.jpg)
IF THE RELATIVE IMPORTANCE OF THESE CONTRIBUTIONS VARIES,
THEN THE APPARENT TELECONNECTION FROM THEIR SUM (THE PDO) COULD BE
NONSTATIONARY EVEN IF TELECONNECTIONS
TO THE INDIVIDUAL PDO PROCESSES WERE FIXED.
“ ”
Newman et al., in revision Bulletin of the American Meteorological Society
![Page 119: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/119.jpg)
![Page 120: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/120.jpg)
Source: Zanche!in et al., Climate of the Past, 2015
PACIFIC/ NORTH AMERICAN
PATTERN
![Page 121: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/121.jpg)
THESE RESULTS CALL FOR STRENGTHENED COOPERATION BETWEEN THE CLIMATE PROXY
AND CLIMATE MODELING COMMUNITIES IN ORDER TO IMPROVE OUR KNOWLEDGE ABOUT THE EARLY 19TH-CENTURY PNA
AND TO SOLVE THE RELATED RECONSTRUCTION-SIMULATED DISCREPANCY.
“ ”
Zanche!in et al., 2015 Climate of the Past
![Page 122: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/122.jpg)
![Page 123: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/123.jpg)
Dr. David Meko University of Arizona
![Page 124: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/124.jpg)
Source: Meko, Ph.D. dissertation, 1981
![Page 125: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/125.jpg)
TREE-RING RECORDS ARE ABLE TO TRACK DECADAL CLIMATE VARIABILITY, AT LEAST IN SOME CASES.
BUT WE NEED TO SPECIFICALLY TEST THEIR FIDELITY AT THOSE TIMESCALES.
![Page 126: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/126.jpg)
TREE-RING ESTIMATES OF DECADAL CLIMATE MODES ARE NOT CONSISTENT PRIOR TO THE 20TH CENTURY.
THAT LACK OF AGREEMENT COULD TELL US SOMETHING ABOUT THE STABILITY OF TELECONNECTIONS
ASSOCIATED WITH DECADAL MODES.
![Page 127: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/127.jpg)
ACCURATELY EXTRACTING DECADAL SIGNALS FROM TREE-RING PROXIES IS A LONGSTANDING PROBLEM.
THE PALEO-COMMUNITY MIGHT NEED TO ADOPT (AND TEST) NEW STRATEGIES TO DEAL WITH
OUR PARTICULAR DECADAL ‘CONUNDRUM’.
![Page 128: Large-scale dendrochronology and low-frequency climate variability](https://reader037.vdocuments.net/reader037/viewer/2022102816/55be3a37bb61eba6458b476f/html5/thumbnails/128.jpg)
SCOTT ST. GEORGE DEPARTMENT OF GEOGRAPHY, ENVIRONMENT AND SOCIETY
UNIVERSITY OF MINNESOTA
@SCOTTSTGEORGE