Kelly Redmond - US Drought Monitor Forum Presentation - April 14, 2015
Diagnosis of the US Drought of 2012:
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Eugene S. Takle Professor Department of Agronomy Department of Geological and Atmospheric Science Director, Climate Science Program Iowa State University Ames, IA 50011 [email protected] Diagnosis of the US Drought of 2012: Climate Change, Agriculture, and Drought: Lessons from the 2012 Growing Season
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Diagnosis of the US Drought of 2012:. Eugene S. Takle Professor Department of Agronomy Department of Geological and Atmospheric Science Director, Climate Science Program Iowa State University Ames, IA 50011 [email protected]. Climate Change, Agriculture, and Drought: - PowerPoint PPT Presentation
Transcript of Diagnosis of the US Drought of 2012:
Eugene S. TakleProfessor
Department of AgronomyDepartment of Geological and Atmospheric Science
Director, Climate Science ProgramIowa State University
Ames, IA 50011
Diagnosis of the US Drought of 2012:
Climate Change, Agriculture, and Drought: Lessons from the 2012 Growing Season
Historical Perspective: Relevant Recent Climate
Conditions
Iowa State-Wide Average Data
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
0
2
4
6
8
10
12
14
Number of Days with a Maximum Temperature Greater Than or Equal to 100°F
Year
Num
ber o
f Day
s
Des Moines, Iowa Airport Data
1974: 71977: 8
1983: 13
1988: 10
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
0
2
4
6
8
10
12
14
Number of Days with a Maximum Temperature Greater Than or Equal to 100°F
Year
Num
ber o
f Day
s 1974: 71977: 8
1983: 13
1988: 10
6 days ≥ 100oF in 23 years
Des Moines, Iowa Airport Data
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
0
2
4
6
8
10
12
14
Number of Days with a Maximum Temperature Greater Than or Equal to 100°F
Year
Num
ber o
f Day
s 1974: 71977: 8
1983: 13
1988: 1011 days in 2012
6 days ≥ 100oF in 23 years
Des Moines, Iowa Airport Data
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
0.0
5.0
10.0
15.0
20.0
25.0
R² = 0.0354248508187915
Winter Average State-Wide Temperature Minimum
Year
Min
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
15.0
20.0
25.0
30.0
35.0
40.0
45.0
R² = 0.013473121517232
Winter Average State-Wide Temperature Maximum
Year
Max
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
70.0
75.0
80.0
85.0
90.0
95.0
R² = 0.0574177778298495
Summer Average State-Wide Temperature Maximum
Year
Max
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
52.0
54.0
56.0
58.0
60.0
62.0
64.0
66.0
R² = 0.0382239214204405
Summer Average State-Wide Temperature Minimum
Year
Min
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
0.0
5.0
10.0
15.0
20.0
25.0
R² = 0.0354248508187915
Winter Average State-Wide Temperature Minimum
Year
Min
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
15.0
20.0
25.0
30.0
35.0
40.0
45.0
R² = 0.0134731215172317
Winter Average State-Wide Temperature Maximum
Year
Max
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
70.0
75.0
80.0
85.0
90.0
95.0
R² = 0.057417777829848
Summer Average State-Wide Temperature Maximum
Year
Max
Tem
pera
ture
(°F)
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
52.0
54.0
56.0
58.0
60.0
62.0
64.0
66.0
R² = 0.0382239214204407
Summer Average State-Wide Temperature Minimum
Year
Min
Tem
pera
ture
(°F)
Iowa State-Wide Average Data
18701877188418911898190519121919192619331940194719541961196819751982198919962003201010.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
R² = 0.010782029618847
Total Annual State-Wide Average Precipitation
Year
Tota
l Ave
rage
Pre
cipi
tatio
n (in
ches
)
Iowa State-Wide Average Data
18701877188418911898190519121919192619331940194719541961196819751982198919962003201010.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
R² = 0.010782029618847
Total Annual State-Wide Average Precipitation
Year
Tota
l Ave
rage
Pre
cipi
tatio
n (in
ches
) 1 yearTotals above 40”
5 years
Iowa State-Wide Average Data
18701877188418911898190519121919192619331940194719541961196819751982198919962003201010.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
R² = 0.010782029618847
Total Annual State-Wide Average Precipitation
Year
Tota
l Ave
rage
Pre
cipi
tatio
n (in
ches
)
1990-2011 highly favorable precip for crops
Cedar Rapids, Iowa Data
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
10
20
30
40
50
60
70
R² = 0.185027251740679
Cedar Rapids Total Annual Precipitation (inches)
Year
Tota
l Pre
cipi
tatio
n (in
ches
)
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
10
20
30
40
50
60
70
R² = 0.185027251740679
Cedar Rapids Total Annual Precipitation (inches)
Year
Tota
l Pre
cipi
tatio
n (in
ches
)
28.0” 39% increase 39.0”
Cedar Rapids, Iowa Data
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
10
20
30
40
50
60
70
R² = 0.185027251740679
Cedar Rapids Total Annual Precipitation (inches)
Year
Tota
l Pre
cipi
tatio
n (in
ches
)
Years with more than 40 inches
2
18
Cedar Rapids, Iowa Data
“One of the clearest trends in the United States observational record is an increasing frequency and intensity of heavy precipitation events… Over the last century there was a 50% increase in the frequency of days with precipitation over 101.6 mm (four inches) in the upper midwestern U.S.; this trend is statistically significant “
Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.
Cedar Rapids, Iowa Data
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
2
4
6
8
10
12
14
Cedar Rapids PrecipitationDays per Year with Greater Than or Equal to 1.25 inches
Year
Num
ber o
f Day
s
Cedar Rapids, Iowa Data
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
2
4
6
8
10
12
14
Cedar Rapids PrecipitationDays per Year with Greater Than or Equal to 1.25 inches
Year
Num
ber o
f Day
s
Creates runoff
Cedar Rapids, Iowa Data
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
2
4
6
8
10
12
14
Cedar Rapids PrecipitationDays per Year with Greater Than or Equal to 1.25 inches
Year
Num
ber o
f Day
s
3.6 days 6.1 days69% increase
1890189619021908191419201926193219381944195019561962196819741980198619921998200420100
2
4
6
8
10
12
14
Cedar Rapids PrecipitationDays per Year with Greater Than or Equal to 1.25 inches
Year
Num
ber o
f Day
s
Number of Years with More than 8 Occurrences
0 9
Cedar Rapids, Iowa Data
Amplification of the Seasonality of PrecipitationSpring
WinterSummer
Fall
21.2 => 25.3 inches (22% increase) 12.1 => 10.5 inches (13% decrease)
Amplification of the Seasonality of PrecipitationSpring
WinterSummer
Fall
2012 1988
1988 wasHotter inAugust
2012 1988
Precip
Stress
Normal 2012 Normal 1988
NormalNormal
2012 1988
Accumdeficit
Accumstress
2012 1988
1988 wasHotter inAugust
2012 1988
Precip
Stress
Normal 2012 Normal 1988
NormalNormal
2012 1988
Accumstress
12 inches (30 cm) below normal
going into 2013
Mean Summer (JJA) Dew-Point Temperatures for Des Moines, IA
Rise of 3oF in 42 years
12% rise in water content in 42 years
19701972
19741976
19781980
19821984
19861988
19901992
19941996
19982000
20022004
20062008
20102012
52.0
54.0
56.0
58.0
60.0
62.0
64.0
66.0
R² = 0.0382239214204407
Summer Average State-Wide Temperature Minimum
Year
Min
Tem
pera
ture
(°F)
Iowa Statewide Summer Minimum Daily
Temperature
Illinois Yield Decline with Increasing Minimum Daily
Temperature during Grain-Fill Period
Illinois Decline of Length of Grain-Fill Period with Increasing Minimum Daily Temperature
High nighttime temperatures reduce the length of the grain filling period Extreme high temperatures during pollination Changes in planting dates due to wet soils Increased damage due to pests and pathogens resulting from pest overwintering in antecedent warmer winters and/or higher July-August humidity
Yield declines from potential are caused by many factors in addition to reduced precipitation
2012 Anecdotes from Iowa Producers
Dewfall may have contributed to soil moisture (moist rings observed in soil around plant stem that persists into mid-morning hours)
Pattern subsurface drainage tile may be drying out high locations in fields (high-yielding well drained areas have lowest yields)
2012 Anecdotes from Iowa Producers
Fields with corn-after-corn had reduced yields
Extremely dry conditions exposed differences in management (tillage methods, residue management, planting dates)
2012 Anecdotes from Iowa Producers
High within-field variability (soils, other); 0-200 bu/acre on one combine round
Most producers were expecting yields to be much lower and were pleasantly surprised at harvest
Iowa Agricultural Producers are Adapting to Climate Change:
Longer growing season: plant earlier, plant longer season hybrids, harvest later
Wetter springs: larger machinery enables planting in smaller weather windows
More summer precipitation: higher planting densities for higher yields Wetter springs and summers: more subsurface drainage tile is being
installed, closer spacing, sloped surfaces Fewer extreme heat events: higher planting densities, fewer pollination
failures Higher humidity: more spraying for pathogens favored by moist
conditions. more problems with fall crop dry-down, wider bean heads for faster harvest due to shorter harvest period during the daytime.
Drier autumns: delay harvest to take advantage of natural dry-down conditions, thereby reducing fuel costs
So what about droughts in the future?
Iowa State-Wide Average Data
18701877188418911898190519121919192619331940194719541961196819751982198919962003201010.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
R² = 0.010782029618847
Total Annual State-Wide Average Precipitation
Year
Tota
l Ave
rage
Pre
cipi
tatio
n (in
ches
) 1 yearTotals above 40”
5 years
Iowa State-Wide Average Data
18701877188418911898190519121919192619331940194719541961196819751982198919962003201010.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
R² = 0.010782029618847
Total Annual State-Wide Average Precipitation
Year
Tota
l Ave
rage
Pre
cipi
tatio
n (in
ches
) 1 yearTotals above 40”
7 years3 years
5 years
Totals below 25”2012
Projected Future Variability in Growing Season Precipitation for Iowa
More extreme high precip years
More extreme low precip years
CJ Anderson, ISU
Future Variability in Growing Season Precipitation for Iowa
More extreme high precip years
More extreme low precip years
CJ Anderson, ISU
Lines drawn by eye
Summary
The climate of 1990-2011 has been highly favorable for agriculture in Iowa and the US Midwest
Higher precipitation of the last 40 years has suppressed Iowa daily max temperatures in summer; dry summers in the future will unmask underlying climate warming trend
Frequency of precipitation extremes has increased
Recent trends and future projections suggest higher frequency of both floods and droughts
For More Information:
Climate Science ProgramIowa State University
http://climate.engineering.iastate.edu/http://www.meteor.iastate.edu/faculty/takle/
Acknowledgements: R Elmore for producer comments; discussions with C J Anderson, S E Taylor
