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

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

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

Agroclimatic zones of Ukraine

Winter wheat yield in

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)

Global factors [ Atlantic Multidecadal OscillationPacific Decadal Oscillation [

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

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

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

What are the joint AMO and PDO manifestations?

PDO-AMO index as an indicator of joint influence

Joint AMO & PDO manifestations R=-0,57

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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