Extreme Events and Climate Variability

Extreme Events and Climate

Variability

Issues:

Scientists are telling us that global warming means more extreme weather.

Every year we seem to experience weather extremes.

What is the origin of extreme events?

1 8 8 0 1 9 0 0 1 9 2 0 1 9 4 0 1 9 6 0 1 9 8 0 2 0 0 0 - 1 . 2

- 0 . 9 - 0 . 6 - 0 . 3 0 . 0 0 . 3 0 . 6 0 . 9 1 . 2 - 0 . 4 - 0 . 1 0 . 2 0 . 5 0 . 8

Anomaly (°C)

- 0 . 6 - 0 . 3 0 . 0 0 . 3 0 . 6 0 . 9

L a n d O c e a n

L a n d a n d O c e a n

Anomaly (°C)Anomaly (°C)

a

b

c

1 8 8 0 1 9 0 0 1 9 2 0 1 9 4 0 1 9 6 0 1 9 8 0 2 0 0 0

1 8 8 0 1 9 0 0 1 9 2 0 1 9 4 0 1 9 6 0 1 9 8 0 2 0 0 0

A Major Issue for All Countries Is Global Warming and Its Regional Impacts

Seasonal Climate Impacts Depend on the Simultaneous Influences of:

Natural Climate Variability El Nino/La Nina

Pacific Decadal Oscillation (PDO)

Arctic Oscillation (weak impact in Tropics) Climate Change

Atmospheric Noise

Extreme Events are Mostly Related to Circulation Changes, i.e. to Variability

The El Nino/Southern Oscillation (ENSO) is a major factor in

global climate variability.

R e f e r e n c e : N a t h a n M a n t u a U n i v e r s i t y o f W a s h i n g t o n

The Pacific Decadal Oscillation (PDO)

Typical wintertime Sea Surface Temperature (colors), Sea Level Pressure (contours) and surface windstress

(arrows) anomaly patterns during warm and cool phases of PDO

D e p a r t u r e f r o m N o r m a l ( m m ) E l N i n o ( J u l y 1 9 9 7 - J u n e 1 9 9 8 )~

R a i n f a l l C h a n g e s A s s o c i a t e d w i t h E N S O a r e t h e L a r g e s t S o u r c e o f V a r i a b i l i t y i n t h e T r o p i c s

E N S O A l s o I m p a c t s H u r r i c a n e A c t i v i t y

L a N i n a ( J u l y 1 9 9 8 - J u n e 1 9 9 9 )~

Societal Impacts from 1997/98 El Nino

1 . C r o p / S t o c k D a m a g e 2 . E n e r g y S a v i n g s 3 . F a m i n e

4 . F i r e s

5 . F i s h e r i e s D i s r u p t i o n 6 . H e a l t h R i s k s

7 . H u m a n F a t a l i t i e s

8 . P e s t s I n c r e a s e d 9 . P r o p e r t y D a m a g e 1 0 . T o u r i s m D e c r e a s e d 1 1 . T r a n s p o r t a t i o n P r o b l e m s 1 2 . S o c i a l D i s r u p t i o n s

1 3 . W i l d l i f e F a t a l i t i e s 1 4 . W a t e r R a t i o n i n g

C l i m a t e P r e d i c t i o n C e n t e r

1

1 ⁸

1 0 1 1 1 3 ⁶

4 41

6

1 0 1 1

1 4 3

4 7

1 1 1 2

1

5 1 4 1 4

1 1 1

1 4 4 3 6 8

9

9 9

1 0 1 3 1 2

5 1

1 4

6 9

9

1 1

7 8 9 1 9

4 7

8 9 1 3 1 1

5 2

Major Weather-Related Natural Disasters (1999 La Nina)

6 0 N 5 0 N 4 0 N 3 0 N 2 0 N 1 0 N E Q 1 0 S 2 0 S 3 0 S 4 0 S 5 0 S 6 0 S

0 6 0 E 1 2 0 E 1 8 0 1 2 0 W 6 0 W 0

C l i m a t e P r e d i c t i o n C e n t e r

S S

S S S

S S

F F F F F F

F

F F F

F F F F

F F

F F F F F F

F

F F

F F

F

H H

H H

D D

S S t o r m s , H a i l , T o r n a d o e s

F F l o o d s , L a n d s l i d e s

H H u r r i c a n e s , T y p h o o n s

D D r o u g h t

F l o o d 5 5 , 3 6 0 $ 1 . 3 B S t o r m s 1 6 , 8 6 3 $ 1 7 . 0 B D r o u g h t s 4 0 4 - C o l d W a v e s 4 0 9 $ 1 . 3 B

V i c t i m s I n s u r e d L o s s e s

R e g i o n a l 1 9 9 9 F l o o d s P o s s i b l y L i n k e d t o L a N i n a D a t e E v e n t

A p r i l 9 - 1 6 M u d s l i d e s & h e a v y r a i n s C o l u m b i a : C a u c a , A r g e l i a

M a y 5 - 1 5 H i g h w a t e r i n A m a z o n a s , P e r u A u g u s t 1 5 - 2 2 F l o o d i n g i n e a s t e r n V e n e z u e l a

A u g 3 0 - S e p t 1 1 F l o o d i n g i n C o l u m b i a : A n t i o q u i a , C o r d o b a , C h o c o

S e p t 1 2 - 2 9 P e r s i s t e n t r a i n s , f l o o d s , m u d s l i d e s i n C o l u m b i a , H o n d u r a s , N i c a r a g u a ,

G u a t a m a l a

D e c 1 2 - 1 9 M a j o r f l o o d i n g a n d m u d s l i d e s i n V e n e z u e l a ( 5 0 , 0 0 0 + v i c t i m s )

Impacts of December 1999 Floods in Venezuela

Typical winter Weather

Anomalies and Atmosphere Circulation Changes During El Nino & La Nina

E x t e n d e d P a c i f i c J e t S t r e a m

& A m p l i f i e d S t o r m T r a c k

L

L o w P r e s s u r e

P o l a r J e t S t r e a m W a r m

C o l d D r y

D r y W e t

P e r s is t e n t

E l N i n o^~

H

V a r i a b l e P a c i f i c J e t S t r e a m B l o c k i n g

H i g h P r e s s u r e P o l a r

J e t S t r e a m

C o l d

D r y

D r y W e t

W a r m W e t

V a r i a b l e

L a N i n a~

J e t S t r e a m S h i f t s A s s o c i a t e d w i t h C l i m a t e V a r i a b i l i t y P r o d u c e R e g i o n a l C h a n g e s I n E x t r e m e W e a t h e r E v e n t s

L o c a t i o n s F o r M a j o r S t o r m s ( D a y s P e r W i n t e r S e a s o n ) E x t e n s iv e S t o r m s

D e c 9 7 - M a r 9 8

M a s s i v e I c e S t o r m J a n 9 8 S t r o n g

“ N o r t h e a s t e r ” S t o r m s J a n - F e b 9 8 T o r n a d o O u t b r e a k

F e b 9 8

F r e q u e n t S t o r m s N o v 9 7 - M a r 9 8

E x a m p l e s o f C l i m a t e C o n t r o l O v e r W e a t h e r P a t t e r n s . T h e B a s i s o f L i n k i n g C l i m a t e a n d W e a t h e r

L A N i n a 1 9 9 8 - 1 9 9 9~

A b o v e A v e r a g e S t o r m s , H u r r i c a n e

F o r c e W i n d s N o v 9 8 - F e b 9 9

A c t i v e H u r r i c a n e S e a s o n A u g - N o v 9 8

T o r n a d o e s J a n 1 9 9 9

N o M a j o r “ N o r t h e a s t e r s ”

B e l o w N o r m a l S t o r m i n e s s D e c 9 8 - F e b 9 9

M a j o r I c e S t o r m J a n 9 9 M a j o r

S n o w S t o r m J a n 9 9

E x t e n s i v e I c e S t o r m D e c 9 8 D r o u g h t

S p r i n g 1 9 9 9

D i m i n i s h e d H u r r i c a n e

T h r e a t

T h e P a c i f i c D e c a d a l O s c i l l a t i o n ( P D O )

t y p i c a l w i n t e r t i m e S e a S u r f a c e T e m p e r a t u r e ( c o l o r s ) , S e a L e v e l P r e s s u r e ( c o n t o u r s ) a n d s u r f a c e w i n d s t r e s s ( a r r o w s ) a n o m a l y p a t t e r n s d u r i n g w a r m a n d c o o l p h a s e s o f P D O

w a r m p h a s e c o o l p h a s e

R e f e r e n c e : N a t h a n M a n t u a U n i v e r s i t y o f W a s h i n g t o n

Contributions to Surface Temperature Trend from 1950-1999

T o t a l T r e n d P a c i f i c D e c a d e l O s c i l l a t i o n

A r c t i c O s c i l l a t i o n G l o b a l W a r m i n g

SUMMARY

Extremes result from:

- major climate anomalies (e.g. especially El Nino and La Nina in Tropics)

- unusual atmospheric circulation patterns (mostly related to climate variability)

- factors acting together for air temperature (e.g. ENSO, PDO, AO, global warming)

The impacts of the warming trend on circulation changes, i.e. also extremes, is still a research issue