What do tree rings tell us about drought and climate ... - Colorado
What do tree rings tell us about drought and climate ... - Colorado
What do tree rings tell us about drought and climate ... - Colorado
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Prehistoric Context for<br />
Western Drought<br />
Histories of<br />
Climate<br />
Fire<br />
Insect<br />
outbreaks<br />
Tree<br />
demography<br />
Julio Betancourt, Steve Gray<br />
Greg McCabe, Hugo Hidalgo<br />
GreatDrought<br />
AD1266-1299<br />
AD1266 1299<br />
Cross-dating<br />
Last beam<br />
cut in<br />
AD 1286<br />
Betatakin
NE Utah Monthly Precipitation 1895-2002<br />
1895 2002
July-July Precipitation (cm)<br />
Tree-Ring Tree Ring width series capture both interannual<br />
<strong>and</strong> interdecadal variations in <strong>climate</strong><br />
Calibration for the NE Utah/SW Wyoming Precipitation Reconstruction<br />
35<br />
30<br />
25<br />
20<br />
15<br />
Observed vs<br />
10<br />
Predicted<br />
1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995
Corona<strong>do</strong>’s<br />
Entrada<br />
?<br />
Significant Cultural Events
Connie Woodho<strong>us</strong>e<br />
www.ncdc.noaa.gov/paleo/streamflow
Ni, Cavazos, Hughes, Comrie & Funkho<strong>us</strong>er (2002)<br />
http://www.ngdc.noaa.gov/paleo/<br />
November-April precipitation (mm)<br />
140<br />
120<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
1000 1200 1400 1600 1800 2000
http://www.ngdc.noaa.gov/paleo/
Some applications of <strong>tree</strong>-ring <strong>tree</strong> ring data<br />
towards underst<strong>and</strong>ing <strong>drought</strong><br />
- structure of <strong>drought</strong>s<br />
- how representative is instrumental record?<br />
- worst <strong>and</strong> best-case scenarios for management<br />
- geography of <strong>drought</strong><br />
- patterns <strong>and</strong> sources of synchroneity of<br />
decadal to centennial oscillations at<br />
regional to subcontinental scales<br />
- temperature reconstructions from upper <strong>tree</strong>line<br />
- ecological impacts of <strong>drought</strong>
Reconstructed July-July precipitation<br />
40<br />
30<br />
20<br />
10<br />
0<br />
Use of the <strong>tree</strong>-ring<br />
record to underst<strong>and</strong><br />
structure of <strong>drought</strong>s<br />
NE Utah reconstruction<br />
1578-1579<br />
1550 1560 1570 1580 1590 1600<br />
We tend to celebrate<br />
too early, <strong>and</strong> let a little<br />
rain spoil our resolve
Bighorn Basin<br />
(Upper Missouri)<br />
Uinta Basin<br />
(Upper Colora<strong>do</strong>)<br />
Middle<br />
Rio Gr<strong>and</strong>e
Bighorn River Basin<br />
30% of Yellowstone R.<br />
contribution to<br />
Upper Missouri River<br />
Gray, Jackson,<br />
Fastie & Betancourt<br />
(2004) J. Climate<br />
Great<br />
Drought<br />
Late 16 th cent<br />
Mega<strong>drought</strong><br />
Variability<br />
dampened in<br />
20 th century<br />
Bighorn<br />
Lake
Lake Powell Delta June 02 March 03<br />
Uinta Basin<br />
Great<br />
Drought<br />
Late 16 th<br />
Century<br />
Mega<strong>drought</strong><br />
20 th<br />
Cent.<br />
Gray, Jackson &<br />
Betancourt (2004)<br />
JAWRA
Sept 1951 Elephant Butte, NM Jan 2003<br />
Reconstructed PDSI<br />
Middle Rio Gr<strong>and</strong>e Basin, NM AD<br />
Great<br />
Drought<br />
Late 16 th cent<br />
Mega<strong>drought</strong><br />
Late 16 th cent<br />
Mega<strong>drought</strong><br />
Grissino-Mayer, Baisan,<br />
Morino, & Swetnam, 2001<br />
Highly<br />
variable<br />
Large 20 Great<br />
Drought<br />
th cent. variability
Worst Case Scenarios for Water & L<strong>and</strong> Managers<br />
Uinta Basin<br />
(Upper Colora<strong>do</strong>)<br />
AD 1226-2001<br />
Gray, Jackson, &<br />
Betancourt (2004)<br />
Central Rio<br />
Gr<strong>and</strong>e Basin<br />
AD 622-1992<br />
Grissino-Mayer,Baisan<br />
& Swetnam (2001)<br />
(1) 1250-1288<br />
(2) 1437-1477<br />
(3) 1772-1786<br />
(4) 1566-1593<br />
(5) 1625-1640<br />
(1) 1571-1593<br />
(2) 1272-1297<br />
(3) 1945-1963<br />
(4) 701-712<br />
(5) 1131-1151
Best Case Scenarios for Water & L<strong>and</strong> Managers<br />
Uinta Basin<br />
(Upper Colora<strong>do</strong>)<br />
AD 1226-2001<br />
Gray, Jackson, Betancourt<br />
& Eddy (2004)<br />
Central Rio<br />
Gr<strong>and</strong>e Basin<br />
AD 622-1992<br />
Grissino-Mayer,Baisan<br />
& Swetnam (2001)<br />
(1) 1594-1624<br />
(2) 1837-1868<br />
(3) 1965-1987<br />
(4) 1478-1492<br />
(5) 1330-1346<br />
(1) 1553-1557<br />
(2) 1627-1653<br />
(3) 1978-1992<br />
(4) 724-733<br />
(5) 1377-1396
5,000,000<br />
4,500,000<br />
4,000,000<br />
3,500,000<br />
3,000,000<br />
2,500,000<br />
2,000,000<br />
1,500,000<br />
1,000,000<br />
500,000<br />
0<br />
1860<br />
Population Growth in Colora<strong>do</strong><br />
(Should this really be our reference period?)<br />
3 rd 1965-1995 1965 1995<br />
wettest period<br />
in last 1000 yrs<br />
Colora<strong>do</strong> population <strong>do</strong>ubled<br />
From 2 to 4 million<br />
1880<br />
1900<br />
1920<br />
1940<br />
1960<br />
1980<br />
2000
LATITUDE<br />
60<br />
50<br />
40<br />
30<br />
20<br />
OLD (425) AND NEW (835) TREE-RING CHRONOLOGY<br />
NETWORK FOR RECONSTRUCTING DROUGHT<br />
OLD NETWORK<br />
NEW NETWORK<br />
CHRONOLOGIES<br />
-140 -120 -100 -80 -60<br />
LONGITUDE<br />
Cook, Meko, Stahle, & Cleavel<strong>and</strong> (1999) J. Climate<br />
1700-2000, http://www.ngdc.noaa.gov/paleo/<br />
Kr<strong>us</strong>ik & Cook (2004) North American Drought Atlas;<br />
last 2005 years
Western<br />
U.S. grid<br />
Kr<strong>us</strong>ik & Cook (2004) North American Drought Atlas; last 2005 years
1941<br />
1941<br />
Instrumental<br />
Tree-Ring Tree Ring
1954<br />
1954<br />
Instrumental<br />
Tree-Ring Tree Ring
Severe Droughts = Widespread Droughts<br />
Cook, Meko, Stahle, & Cleavel<strong>and</strong> (1999)
1950’s 1950<br />
1930’s 1930<br />
In Cook et et al. al<br />
gridded PDSI<br />
reconstructions<br />
1950’s-type<br />
1950 type<br />
<strong>drought</strong>s<br />
6X more common<br />
than 1930’s-type<br />
1930 type<br />
<strong>drought</strong>s
RWI<br />
Period (Years)<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2 4<br />
8<br />
16<br />
32<br />
64<br />
128<br />
256<br />
512<br />
Strong evidence for multidecadal (30-70 yr) persistence <strong>and</strong><br />
cross-regional synchrony<br />
a. Climate Regions<br />
Yellowstone Bighorn<br />
Basin<br />
Colora<strong>do</strong><br />
Plateau<br />
d. Colora<strong>do</strong> Plateau<br />
SW<br />
Rockies<br />
SE<br />
Rockies<br />
1400 1600 1800<br />
0 0.003 0.04 0.15 0.49<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2 4<br />
8<br />
16<br />
32<br />
64<br />
128<br />
256<br />
512<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2 4<br />
8<br />
16<br />
32<br />
64<br />
128<br />
256<br />
512<br />
b. Yellowstone<br />
1400 1600 1800<br />
0 0.016 0.06 0.24 0.98<br />
e. SE Rocky Mountains<br />
1400 1600 1800<br />
0 0.006 0.05 0.15 0.45<br />
Power (RWI) 2<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2 4<br />
8<br />
16<br />
32<br />
64<br />
128<br />
256<br />
512<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2 4<br />
8<br />
16<br />
32<br />
64<br />
128<br />
256<br />
512<br />
c. Bighorn Basin<br />
1400 1600 1800<br />
0 0.077 0.28 1.1 1.9<br />
f. SW Rocky Mountains<br />
1400 1600 1800<br />
0 0.057 0.18 0.39 0.80<br />
Gray, Betancourt, Fastie, & Jackson (2003) GRL
<strong>What</strong> ca<strong>us</strong>es multidecadal<br />
precip variability?<br />
<strong>What</strong> controls the synchrony<br />
across large basins?<br />
Yellowstone Bighorn<br />
Basin<br />
Colora<strong>do</strong><br />
Plateau<br />
SW<br />
Rockies<br />
SE<br />
Rockies<br />
Gray, Betancourt, Fastie,<br />
& Jackson (2003) GRL<br />
2.0<br />
2.0<br />
1.5<br />
1.0 0.5<br />
0.5<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
2.0<br />
1.5<br />
1.5<br />
1.0<br />
1.00.5<br />
0.5<br />
Yellowstone<br />
Bighorn Basin<br />
Colora<strong>do</strong> Plateau<br />
SE Rocky Mountains<br />
SW Rocky Mountains<br />
1300 1400 1500 1600 1700 1800 1900
PDO reconstruction from SW USA/N Mexico <strong>tree</strong> <strong>rings</strong><br />
Biondi, Gershunov & Cayan (2001)
Tree-Ring Tree Ring Sites for AMO Reconstruction<br />
SST anomaly<br />
0.4<br />
0.2<br />
0<br />
-0.2<br />
-0.4<br />
Instrumental<br />
AMO<br />
1850 1900 1950 2000<br />
Gray, Graumlich,<br />
Betancourt, & Pederson<br />
In press GRL
Weak AMO<br />
1550 1600 1650 1700 1750 1800 1850 1900 1950 2000<br />
Gray, Graumlich, Betancourt & Pederson, in press GRL
PDO<br />
AMO<br />
Range 1-31 1 31 yrs<br />
Average 6 yrs<br />
Range 9-53 9 53 yrs<br />
Average 23 yrs
20-yr 20 yr moving average of PDSI reconstructions<br />
Vs. 20-yr 20 yr moving average of AMO 1567-1900 1567 1900
PCA of 20-yr 20 yr smoothed, reconstructed PDSI<br />
1536-1967 1536 1967<br />
=PDO =AMO =ENSO<br />
Hidalgo (2004) WRR<br />
WRR
Percentage of total power present at bidecadal <strong>and</strong><br />
multidecadal b<strong>and</strong>s in gridded PDSI <strong>tree</strong>-ring reconstructions<br />
Bidecadal b<strong>and</strong><br />
(8-32 yrs)<br />
Multidecadal<br />
(32-64 yrs)<br />
Hidalgo 2004<br />
WRR<br />
1525-1650 1525 to 1650 1700-1825 1700 to 1825 1700-1975<br />
1850 to 1975<br />
60%<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0
Tree-ring regions<br />
Gray, Graumlich, Betancourt<br />
& Pederson, in prep<br />
Wavelet analysis of AMO proxy
11-yr moving<br />
departures<br />
of annual PDO,<br />
AMO & Colora<strong>do</strong><br />
River streamflow<br />
at Lee’s Ferry<br />
1661-1961<br />
PDO departures<br />
departures<br />
McCabe, Hidalgo,<br />
Gray & Betancourt in prep.<br />
+PDO<br />
-AMO AMO<br />
-PDO PDO<br />
-AMO AMO<br />
AMO Departures<br />
+PDO<br />
+AMO<br />
-PDO PDO<br />
+AMO
Western<br />
U.S. grid<br />
Kr<strong>us</strong>ik & Cook (2004) North American Drought Atlas; last 2005 years
Percent Area of Drought<br />
Western US Drought Area Index (-1 PDSI)<br />
936 1034<br />
1150 1253<br />
Medieval Warm Period<br />
80 yr lowpass<br />
Little Ice Age<br />
1829<br />
1321 1613 1915<br />
800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000<br />
Cook, Woodho<strong>us</strong>e, Eakin, Meko & Stahle (2004) Long-term<br />
aridity changes in the Western United States. Science
Million Acre Feet<br />
8<br />
6<br />
4<br />
2<br />
0<br />
Combined Water Year totals for<br />
Salt, Verde, Tonto & Gila Rivers<br />
Medieval Warm<br />
Period<br />
2.5 maf<br />
600 800 1000 1200 1400 1600 1800 2000<br />
Graybill, Gregory, Funkho<strong>us</strong>er & NialsF. L. (in press)
Uniform heating<br />
Larger<br />
temperature<br />
response in<br />
the West<br />
0 m<br />
50<br />
100<br />
150<br />
~20ºC<br />
Warm, mixed<br />
Surface layer<br />
~20ºC<br />
Deep, cold<br />
ocean waters<br />
Coupled interactions<br />
(i.e. i.e. the the Bjerknes Bjerknes<br />
feedback) feedback)<br />
amplify the<br />
East/west temperature<br />
difference<br />
Cooling by upwelling<br />
opposes forcing in the<br />
East, reducing<br />
temperature response<br />
Ocean dynamical ‘thermostat<br />
thermostat’ (Clement et al. 1996)
Medieval Warm<br />
Period<br />
NH temperature<br />
Palmyra<br />
Coral<br />
Little Ice Age<br />
Wolfe Spörer Sp rer Maunder<br />
Solar Irradiance<br />
Volcanic activity<br />
Cobb et al. (2003) Nature<br />
Nature
Hypothesis: Atlantic & Pacific SST variations<br />
also govern centennial-scale centennial scale trends<br />
in western U.S. <strong>drought</strong><br />
Medieval Warm Period<br />
AD 900-1300 900 1300<br />
Cool<br />
D<br />
R<br />
Y<br />
Warm<br />
Warm<br />
Little Ice Age<br />
AD 1400-1850 1400 1850<br />
W<br />
E<br />
T<br />
Cool
St<strong>and</strong>ardized Units<br />
3<br />
2<br />
1<br />
0<br />
-1<br />
-2<br />
-3<br />
Natural precip. variability will modulate warming impacts<br />
warm wet<br />
dry cool<br />
warm<br />
/wet<br />
cold<br />
/dry<br />
600 800 1000 1200<br />
Salzer & Kipfmueller, in press<br />
Temperature & Precipitation Reconstructions<br />
from S Colora<strong>do</strong> Plateau<br />
1400 1600 1800 2000
Ecological Role of Severe Drought<br />
Significant Ecological Resetting Events
Longer, hotter growing seasons accelerate disturbance/<br />
succession cycles <strong>and</strong> produce greater ecological synchrony<br />
Disturbances<br />
Broadscale<br />
Mortality<br />
Dry & Hot<br />
Hydrologic<br />
Effects??<br />
Lots of<br />
open niches<br />
Increased<br />
Synchrony<br />
Accelerated<br />
Regeneration<br />
of Incumbent<br />
Warm &<br />
Wet<br />
Invasion by<br />
Native &<br />
Non-native<br />
Non native<br />
Species
Demographic clocks are being reset by wildfires & dieoffs<br />
Can we predict the outcomes of succession?<br />
Courtesy of Neil Cobb
•El Niños impose short-lived breaks in even the most severe<br />
<strong>drought</strong>s, testing the resolve of <strong>drought</strong> planners<br />
•Climate variability is a spatially moving target; we should<br />
generalize only from regionally integrated <strong>tree</strong>-ring records<br />
•There appear to be inherent statistical relationships<br />
between <strong>drought</strong> location, extent, duration & severity<br />
•1950’s <strong>and</strong> 1999-2004 were 6X more common than 1930’stype<br />
<strong>drought</strong>s in last 500 years<br />
•1965-1995 one of wettest periods in last 1000 years<br />
•AMO influenced frequency, persistence, extent &<br />
multi-basin synchrony of <strong>drought</strong> & fire in last millennium<br />
•AMO/PDO induces D2M fluctuations in water availability &<br />
Ecosystems; complicated by warming trends<br />
•Risk increases with time that extraction leases authorized<br />
in periods of surpl<strong>us</strong> will carry over into deficit periods