Drought! Bill Patzert [email protected] 26 February 2014 How Long Will this Drought Last? Let’s Look at the Data!
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Drought!
Bill [email protected]
26 February 2014
How Long Will this Drought Last?Let’s Look at the Data!
January 18, 2013 January 18, 2014
Record Drought in 2013-2014• L.A. (CA) Calendar Year 2013
- Jan – Dec = 3.60” - Driest in 135 yrs
• CA Water/Snow Year 2013 – 2014 - L.A. = 1.20” (~12% of norm, 10.72”)
• Most of West in 3+ year drought
• Drought started in 1999? - 11 of last 15 years below normal
L.A. Resident,
MWD Customer
Strongly Modulates:• Precipitation/Snow• Water Supply• Global Temperature• Land & Ocean Ecosystems
Why? Pacific DecadalOscillation & Drought
The Pacific Decadal OscillationSea Surface Temperature Pattern
Warms Pacific (Earth) Cools Pacific (Earth)
• No Trend!
• Highly variable
- 38.32” wettest yr (2006–2007)
- 3.21” driest yr (2004–2005)
- 11 of past 16 yrs below ‘normal’
• Strongly Modulated by:
- ‘Events’ (Atmospheric River, 30-70%)
- Interannual (El Niño, La Niña & La Nada)
- Decadal (Pacific Decadal Oscillation)
California Precipitation
December 2010 ‘Atmospheric River’ Event
Heavy Winter Rains (50% Annual Rain)13 Wet, Cold Days last two weeks of December
‘10 14.40”at JPL (2.86” normal)
Accounts for 30 to 70% Of Our Rain & Snow!
18
78
18
81
18
84
18
87
18
90
18
93
18
96
18
99
19
02
19
05
19
08
19
11
19
14
19
17
19
20
19
23
19
26
19
29
19
32
19
35
19
38
19
41
19
44
19
47
19
50
19
53
19
56
19
59
19
62
19
65
19
68
19
71
19
74
19
77
19
80
19
83
19
86
19
89
19
92
19
95
19
98
20
01
20
04
20
07
20
10
20
13
0
5
10
15
20
25
30
35
40
45
SEASONAL RAINFALL
Linear (SEASONAL RAINFALL)
10 Year Mean
Year
Inc
he
s
LA Downtown (USC) Annual Rain (12 month total ending June
30th of the year indicated)
38.18"'84
'90
'93
'41
'52'69
'78
'83
'93
'98
'14'58 '66 '73
'86
'92
'95
Data: NOAA NWS(Los Angeles/Oxnard)
'26
Major El Nino's years are indicated
'02
'61'99 Rainfall Rollercoaster!
38.32" '05
3.21" '07
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 460
5
10
15
20
25
Frequency of total rainFrequency of El NinoFrequency of La Nina
Fre
qu
ency
Average of all years: 15.1 inchesAverage of El Nino years: 20.7 inchesAverage of La Nina years: 12.5 inches
Los Angeles Annual Rainfall (1878-2009)Relationship to ENSO
Rain (inches)
Ocean-driven Drought?
El NiñoPositive PDO
La NiñaNegative PDO
Winter 2013–2014 Jet Stream Pattern
Orl
ea
ns
(5
1.9
", 1
31
8m
m)
Sc
oti
a (
47
.3",
12
02
mm
)
Uk
iah
(3
7.2
", 9
45
mm
)
Gra
ton
(4
0.8
", 1
03
7m
m)
Sa
nta
Ro
sa
(2
9.9
",7
60
mm
)
Na
pa
(2
5.2
", 6
39
mm
)
Sa
cra
me
nto
(1
8.3
", 4
64
mm
)
Co
alin
ga
(7
.6",
19
1m
m)
Lo
s B
an
os
(9
.1",
23
0m
m)
Ha
nfo
rd (
8.1
", 2
07
mm
)
Alt
ad
en
a (
20
.2",
51
4m
m)
Lo
s A
ng
ele
s (
15
.0",
38
0m
m)
Sa
nta
An
a (
13
.5",
34
4m
m)
Sa
n D
ieg
o (
10
.1",
25
6m
m)
-10
-5
0
5
10
15
Pe
rce
nt
Ch
an
ge
(%
)California Rainfall ‘No’ Trends
1925-2007From NoCal (left) to SoCal (right)
187818961914193219501968198620040
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
f(x) = 2.47599792431961 x + 4453.84228980321R² = 0.00332183187670054
Sacramento
To
tal A
nn
ua
l Ra
infa
ll (m
m)
1878 1896 1914 1932 1950 1968 1986 20040
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
f(x) = − 1.12954714662207 x + 3858.23364579605R² = 0.000563542652161075
Los Angeles
To
tal A
nn
ua
l Ra
infa
ll (m
m)
Sacramento & Los Angeles Rainfall (1878 – 2004)(Yearly, 10 Year Running Mean & Trend)
If trend is 2.5 cm (1”)/century and
variability
is similar, trend is significant in ~270
years!
Colorado River
190519061907190819091910191119121913191419151916191719181919192019211922192319241925192619271928192919301931193219331934193519361937193819391940194119421943194419451946194719481949195019511952195319541955195619571958195919601961196219631964196519661967196819691970197119721973197419751976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020110.00
5.00
10.00
15.00
20.00
25.00
30.00
0
5
10
15
20
25
30
Colorado River at Lees Ferry, AZAnnual Natural Flow in MAF (1905 -
2013)10-yr Average
Calendar YearProvisional data, subject to change Estimated values for 2011-2013
Co
lora
do
Riv
er
An
nu
al F
low
(M
AF
)
Positive PDO - 1983
The Pacific Decadal Oscillation
Negative PDO - 2014
Anasazi disperse
Megadroughts
Global Temperature
• Global is Warming (Trend is 0.012°F/yr.)
- CO2 increased from 280 to 400 ppm
• Strongly Modulated by:
- ‘Events’ (Weather)
- Interannual (El Niño, La Niña & La
Nada)
- Decadal (Pacific Decadal Oscillation)
- PDO Phase Shift causes ‘GW Hiatus’
or
‘GW Acceleration’
0.012°F/yr.
-PDO -PDO+PDO
Global Annual Temperature Anomalies vs 1951–1980 Average (°C)*
ENSO Modulates Global Temps
*NASA’s Goddard Institute for Space Studies (GISS)
Negative PDO = Hiatus Positive PDO =Rapid Increase
Negative PDO =Recent Hiatus
Global Temperature Anomalies since 1950Pacific Decadal Oscillation Modulates Global Temperatures
Strongly Modulates:• Precipitation/Snow• Water Supply• Global Temperatures• Lots of Other Stuff
Why Drought?Pacific Decadal Oscillation
When Does Drounght End?
September 21, 2002
Since 2005, 250 billion gallons H2O
used in 80,000 wells in 17 States!
Fracking = H2O
6X 4X 2X
CA Population ExplosionStresses Everything!
L.A.-2010
L.A.-1902
It’s us!
• (Naturally) Varying Climate• Global Warming Accelerating• Environment Stressed Out• Expanding Agricultural Demands• Growing Urban Population• Changing Economy• Technology Explosion• New Users (Frackers)
Managing Waterin Semi-Arid CA
Our water management policy is tailored for more wet years than dry years.
The reality is just the opposite.
Even when nature behaves, there are too many water demands
to satisfy all of them.
This drought is a great opportunity to start a real conversation about fundamental changes
in California water policy
Ignoring Reality = Dire Consequences
• Politicians• Lawyers
What’s your worst nightmare?
The Great Flood of 1938
76th Anniversary
February 27 – March 4, 1938
~10.0” of Rain
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