Extreme precipitation over the Ukraine and global climate

change

Vyshkvarkova O., Voskresenskaya E.

Marine Hydrophysical Institute National Academy of Sciences of Ukraine

Sevastopol, Ukraine

The aim of presentation is to study the precipitation inequality, precipitation extremes and their trends over the Ukraine associated with climate change

Data: daily precipitation from Ukrainian hydrometeorological stations for period 1951 - 2005

Methods: 1) concentration index (CI); 2) climate indices

Ukraine topographic map

Precipitation inequality

Concentration index or Gini index (well known in economics)

characterizes the inequality of the share of precipitation intensity into the total amount

Definition of Concentration index (CI)

The line at 45 degrees represents perfect equality. The CI here can be thought of as the ratio of the area that lies between the line of equality and the Lorenz curve over the total area under the line of equality

Martin-Vide J., 2004

Annual CI distributions (1951 – 2005)

CI varies from 0.58 in Carpathian region to 0.64 in the Black Sea and Azov coastal region

minmax

Seasonal CI distributions0.54

The minimum CI value (0.54) is typical for the foothill of Carpathian Mountains in winter season and maximum CI value reached 0.71 in

spring in boundary region between steppe and marine zones

0.71

CI trends distributions in 1951-2005

Negative Positive

Linear trends are mainly negative in the all of seasons The highest values of negative CI trend are typical for the west region, especially in autumn. Positive CI trends are located in south-eastern

Ukraine

year winter spring

summer autumn

Pacific Decadal Oscillation (PDO)

Izmail

0,56

0,58

0,6

0,62

0,64

0,66

w inter spring summer autumn year

CI

PDO - PDO +

Kerch

0,48

0,5

0,52

0,54

0,56

0,58

0,6

0,62

0,64

0,66

w inter spring summer autumn year

CI

PDO - PDO +

Precipitation inequality in positive ( ) and negative phase ( )

Mantua N.J., et al., 1997

Climate shift 1976/1977

How does it work?

А+

А+А-

А-

А-А+

Voskresenskaya E.N., Maslova V.N., 2011

Scheme of storm tracks in positive and negative PDO phases

(PDO -)

0

0,1

0,2

0,3

0,4

С Л Б К Т Ч Л С В Ж Л Г

Час

тота

1948-1976 (ТДО-)

1977-2001 (ТДО+)

Cyc

lone

s fr

eque

ncy

1 2 3 4 5 6 7 8 9 10 11 12

(PDO+)

Vinnitsa

0,54

0,56

0,58

0,6

0,62

0,64

0,66

w inter spring summer autumn year

CI

PDO - PDO +

Kiev

0,54

0,56

0,58

0,6

0,62

0,64

w inter spring summer autumn year

CI

PDO - PDO +

Lvov

0,5

0,52

0,54

0,56

0,58

0,6

0,62

w inter spring summer autumn year

CI

PDO - PDO +

Askaniya Nova

0,52

0,54

0,56

0,58

0,6

0,62

0,64

0,66

w inter spring summer autumn year

CI

PDO - PDO +

Lugansk

0,54

0,56

0,58

0,6

0,62

w inter spring summer autumn year

CI

PDO - PDO +

Ukraine. Precipitation inequality

Climate indices

Precipitation extremes

Absolute thresholds:

The percentile threshold (95th percentile)

1960 1980 2000

0

10

20

30

40

50

60

70

80

90

100

Pre

cip

itat

ion

, mm

Kerch

R30mm

R20mm0

10

20

30

40

50

60

70

80

90

100

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29

Precipitation, mm

Fre

qu

ency

, %

Indices of extreme precipitation

R20mm R30mm

1960 1980 2000

0

1

2

3

4

num

be

r of

ca

ses

Sevastopolwinter, > 20 mm

1960 1980 2000

0

2

4

6

num

ber

of c

ases

Sevastopolsum m er, > 20 m m

1960 1980 2000

0

1

2

num

be

r o

f ca

ses

Sevastopol> 30 m m , sum m er

winter summer summer

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

negative positive

Trends of R20mm and R30mm

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

Precipitation 95th percentile

winter

The maximum values are in Crimea Mountains and the north-west coast of the Black Sea while minimum in north-west (forest zone).

Linear trend are predominantly negative

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 3 8 4 0 4 24 4

4 6

4 8

5 0

5 2

5 4

summerPrecipitation 95th percentile

Summer precipitation of 95th percentile is characterized by a homogeneous distribution with values about 23 – 24 mm.

Linear trends are predominantly positive

Conclusions• Precipitation inequality increases southward of

Ukraine from the north-west and the north-east. Annual and seasonal inequality linear trends are predominantly negative for the most part of the country.

• Precipitation inequality is more strong over the Ukraine in negative phase of Pacific Decadal Oscillation than in the positive phase.

• Linear trends of precipitation extremes are negative in winter and positive in summer on the most territory of Ukraine.

Thank you!