recipitation extremes during 1895-2003 in the continental United States P

Precipitation
extremes during
1895-2003 in the continental
United States
Kenneth E. Kunkel
Illinois State Water Survey
Collaborators: Dave Easterling, Kelly
Redmond, Ken Hubbard, Connie
Woodhouse, Ed Cook
Questions
• Are the frequency and intensity of extremes
changing?
• What is the magnitude of natural variability
in the frequency and intensity of extremes
• What are the implications for the global
change debate?
• Trends in extreme precipitation
• Characteristics of early 20th Century pluvial
• Causes of observed trends
U.S. Climate Data
• U.S. Cooperative Observer Network in
operation since late 1880s
• Daily Observations – Max and Min Temp,
Precip, Snowfall, Snow Depth
• Digitizing of Observations began in 1948
• Miscellaneous projects resulted in the
digitizing of selected data prior to 1948
Until recently, digital
availability of pre-1948 daily
climate data has been deficient
Climate Database
Modernization Project
• U.S. Congress has appropriated funds to
NOAA NESDIS to digitize data records
• One of the first data sets chosen for
digitization was the daily cooperative
records. Digitization of these records
finished for the most part in 2001.
Daily Precipitaiton in TD3200, TD3205, and TD3206
10000
9000
Number of Stations
8000
7000
6000
5000
4000
3000
TD3206
TD3200+TD3205
2000
1000
0
1890
1910
1930
1950
Year
1970
1990
Long-term Stations: 1895-2003
Red – new; Blue - old
Data Set Quality Control
• Basic QC of data performed by National Climatic
Data Center
• A collaborative project, partially funded by NOAA
OGP CCDD, to more completely QC these data
has been completed
• Illinois State Water Survey, National Climatic
Data Center (Dave Easterling), U. of NebraskaLincoln (Ken Hubbard), Desert Research Institute
(Kelly Redmond)
Extremes Definition
•
•
•
•
•
Event Duration – days
Recurrence (threshold exceedance) –years
1,5,10,30-day duration
1,5,20-year recurrence
National index
60
EPI Anomaly (%)
1-day duration
40
20
0
-20
-40
-60
1895 1910 1925 1940 1955 1970 1985 2000
Year
1-yr
5-yr
20-yr
60
EPI Anomaly (%)
40
1d1y
1d5y
1d20y
5d1y
5d5y
5d20y
10d1y
10d5y
10d20y
30d5y
30d20y
20
0
-20
-40
-60
1895
1910
1925
1940
1955
Year
1970
1985
2000
1-dy,1-yr Extreme Precipitation: 1895-1905
Blue = positive anomaly
Red = negative anomaly
1-dy, 1-yr Extreme Precipitation: 1990-2000
Blue = positive anomaly
Red = negative anomaly
Winter
EPI Anomaly (%)
30
20
1d1y
1d5y
10
1d20y
5d1y
0
5d5y
5d20y
-10
10d1y
10d5y
-20
10d20y
30d5y
30d20y
-30
1895
1910
1925
1940
1955
Year
1970
1985
2000
Spring
EPI Anomaly (%)
30
20
1d1y
1d5y
10
1d20y
5d1y
0
5d5y
5d20y
10d1y
-10
10d5y
10d20y
-20
30d5y
30d20y
-30
1895
1910
1925
1940
1955
Year
1970
1985
2000
Summer
30
1d1y
1d5y
EPI Anomaly (%)
20
1d20y
10
5d1y
5d5y
0
5d20y
10d1y
-10
10d5y
10d20y
-20
30d5y
30d20y
-30
1895
1910
1925
1940
1955
Year
1970
1985
2000
Fall
EPI Anomaly (%)
30
20
1d1y
1d5y
10
1d20y
5d1y
0
5d5y
5d20y
-10
10d1y
10d5y
-20
10d20y
30d5y
30d20y
-30
1895
1910
1925
1940
1955
Year
1970
1985
2000
Current Drought in West
• High frequencies in western U.S. occurred shortly
before 1922 Colorado River compact
• Analysis of this period reveals role of extreme
seasons
• Compact based on 16.5 maf annual flow; 19062001 average was 15.1 maf; paleoclimatic
reconstructions indicate 400-year average of only
13.5 maf
West
460
Precipitation (mm)
440
420
400
Total
380
360
340
1895
1910
1925
1940
1955
Year
1970
1985
2000
Tree ring reconstruction
• Tree-ring reconstruction of western US climate
recently extended back to more than 1000 years
before present (Cook et al, Science, in press)
• Comparative analysis tree-ring reconstruction for
early 20th Century pluvial (consecutive years of
positive PDSI, cumulative PDSI sum) – Connie
Woodhouse, Dave Easterling, Ed Cook
Western United States Tree-Ring Climate Reconstruction
Consecutive Years of Positive Palmer Drought Severity Index
# of years
period
cumulative sum average annual
value
9
9
8
7
7
1076-1084
1112-1120
1424-1431
1615-1621
1911-1917
12.86
8.99
6.46
11.51
12.22
1.129
1.000
0.807
1.645
1.750
West (5-day periods)
Precipitation Departure from Normal (mm)
60
40
20
Total
0-12
12-25
0
25-50
>50
-20
-40
-60
1895
1910
1925
1940
1955
Year
1970
1985
2000
West
Precipitation Departure from Normal (mm)
30
20
10
0
-10
-20
-30
1895
1910
1925
1940
1955
1970
Year
Winter
Spring
Summer
Fall
1985
2000
West
250
225
200
Precipitation (mm)
175
150
125
100
75
50
25
0
1880
1900
1920
1940
1960
1980
Summer
Fall
Year
Winter
Spring
2000
2020
Wettest Seasons in Western U.S.
season
precipitation (mm)
*winter 1908-09
winter 1968-69
winter 1939-40
spring 1995
*winter 1915-16
*winter 1913-14
*winter 1914-15
winter 1997-98
winter 1995-96
*spring 1906
winter 1940-41
winter 1979-80
*winter 1910-11
*winter 1905-06
winter 1935-36
209
201
196
189
182
182
182
181
180
178
178
177
176
176
175
Causes
• Studies with GISS GCM
• North Pacific Index
• Cyclone tracks
Klein, W. H., 1957: Principal tracks and mean frequencies of cyclones and
anticyclones in the Northern Hemisphere. U.S. Weather Bureau Research
Paper 40, 60 pp.
U.S. Weather Bureau, Daily Synoptic Series, Historical Weather Maps, Northern
Hemisphere Sea Level, January 1899 to June 1939, Cooperative project of
U.S. Army Air Force and U.S. Weather Bureau, Washington DC 1944.
November-March North Pacific Index
6
4
NPI
2
0
-2
-4
-6
1900
1910 1920
1930
1940
1950
Year
1960 1970
1980
1990
2000
18
Cyclone Frequency
16
14
12
10
8
6
4
2
0
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Year
CONCLUSIONS
• Heavy Precipitation Frequencies were highest
during the late 20th Century but also rather high
during the late 19th and early 20th Century
• The late 20th Century peak may be caused by
Tropical Pacific SST anomalies. The early 20th
Century peak occurs at a time of large positive
values of the NPI and above normal frequency of
cyclones coming ashore in the Pacific Northwest.
Atlantic Multi-decadal Oscillation
0.5
0.4
0.3
AMO
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990
Year
THE END