Drought and Grain Crop Yields over the East European Plain under Influence of Quasibiennial Oscillation of Global Atmospheric Processes

Figure 2

Frequency of severe drought (per/100 years) in the westward QBO phase ((a), (b)) and in the eastward phase ((c), (d)) in May (on the left) and in June (on the right) in the period 1953–2011 according to the SPI data.

(a)

(b)

(c)

(d)