Extreme precipitation over the Ukraine and global climate change

1. Marine Hydrophysical Institute National Academy of Sciences of Ukraine Sevastopol, Ukraine Extreme precipitation over the Ukraine and global climate change Vyshkvarkova O., Voskresenskaya E.

2. 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

3. Ukraine topographic map

4. Precipitation inequalityConcentration index or Gini index (well known in economics)characterizes the inequality of the share of precipitation intensity into the total amount

5. Definition of Concentration index (CI) The line at 45 degrees represents perfect equality. The CIhere 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

6. Annual CI distributions (1951 – 2005) min max CI varies from 0.58 in Carpathian region to 0.64 in the Black Sea and Azov coastal region

7. Seasonal CI distributions 0.54 0.71 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

8. CI trends distributions in 1951-2005 year spring winter summer autumn 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

9. Pacific Decadal Oscillation (PDO) Precipitation inequality in positive ( ) and negative phase ( )

10. А- А+ А+ А+ А- А- How does it work? Scheme of storm tracks in positive andnegative PDO phases Climate shift 1976/1977 (PDO+) (PDO -) Mantua N.J., et al., 1997 Cyclones frequency Voskresenskaya E.N., Maslova V.N., 2011 1 2 3 4 5 6 7 8 9 10 11 12

11. Ukraine. Precipitation inequality

12. Climate indices Precipitation extremes

13. Indices of extreme precipitation Absolute thresholds: The percentile threshold (95th percentile) R30mm R20mm

14. R20mm R30mm summer summer winter Trends of R20mm and R30mm negative positive

15. 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

16. Precipitation 95th percentile summer Summer precipitation of 95th percentile is characterized by a homogeneous distribution with values about 23 – 24 mm. Linear trends are predominantly positive

17. 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.

18. Thank you!