1. V.N. Maslova, E.N. Voskresenskaya, E.V. Dunaevskaya 10 September 2012 Łódź, Poland Joint AMO and PDO manifestations in the winter wheat yield in Ukraine Marine Hydrophysical Institute of the National Academy of Sciences of Ukraine

2. Aim  to study how Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) influence on low- frequency variability of winter wheat yield in Ukraine

3. Data sets  Regional winter wheat yield (1945–2008) in different agroclimatic zones of Ukraine: woodland, forest steppe, steppe  Monthly AMO and PDO indices (1990–2008)  Long-term series of monthly in-situ precipitation & temperature (1990–2008)  Frequency and depth of cyclones and anticyclones (1948–2006) over Ukraine obtained using NCEP/NCAR reanalysis data sets

4. Agroclimatic zones of Ukraine

5. Winter wheat yield in 1945-2008

6. Regional factors  t air and p are mean values for the vegetation period of winter wheat c d – depth of cyclones a f – frequency of anticyclones AIR TEMPERATURE & PRECIPITATION SINOPTIC SYSTEMS (CYCLONES & ANTICYCLONES)

7. Global factors [http://atmoz.org/blog/2008/05/14/timescale-of-the-pdo-nao-and-amo/] Atlantic Multidecadal OscillationPacific Decadal Oscillation [http://jisao.washington.edu/pdo/]

8. 1970 1965-1970 1965 Climate shift in XX century  The climate shift in 1965–75 was found in the variability of winter wheat yield

9. Association with AMO R=-0,6 Average long-term differences Error bars correspond to 99% confidence level

10. Association with PDO Average long-term differences R=0,4 Error bars correspond to 99% confidence level

11. What are the joint AMO and PDO manifestations?

12. PDO-AMO index as an indicator of joint influence

13. Joint AMO & PDO manifestations R=-0,57

14. Conclusions  The climatic shift in 1965–75 associated with multidecadal processes in the ocean-atmosphere system was found in the variability winter wheat yield in Ukraine  During AMO+ or PDO- phases the winter wheat yield is 10–15 centners/ha higher than during AMO- or PDO+ phase  The joint influence of AMO and PDO determines about 30% of the variability of winter wheat yield in Ukraine

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