GROWING-SEASON TEMPERATURES OVER THE FORMER SOVIET-UNION

Analyses of daily mean temperatures during the growing season (days > 5 degrees C) from about 200 stations over the former Soviet Union indi cate that little change has taken place in a number of growing-season- related variables during the last 110 years. We have considered the st art (STR), end (END), duration (DUR), and the number of degree-days ab ove 5 degrees C (DD). Annual average temperatures in the region have w armed by about 1 degrees C, but this increase has been confined to the October-to-April period. Time series of the variables at individual s tations show that there is little correlation between the start and en d dates of the growing season and between the duration and the number of degree-days in the season. Mean May-to-September temperatures at in dividual stations are shown to be highly correlated with the number of degree-days, implying that the average of an appropriate combination of monthly temperatures can be used as a proxy for the number of degre e-days when daily data are not available. The low correlation between degree-day counts and growing season duration in time series at all th e stations is surprising given the strong spatial dependence between t he 1950-1989 averages of the variables at all the stations. The result s have implications for studies concerned with the impacts on growing season temperatures of future climate change.