Rates of change in the potentially effective pre-season temperature (Teff) and in the SOS in relation to the SOSmean during 1982–2008, in the Northern Hemisphere (NH), Eurasia, and North America (NA), respectively.
All regressions shown are significant (P<0.01) ((A) (C) and (E)). The number of pixels in each SOSmean bin, in the NH, Eurasia, and NA, respectively ((B), (D), and (F)). Only pixels with a positive change rate in Teff and a negative SOS-Teff correlation that is significant at P<0.10 level are included. Here Teff is the mean temperature of the pre-season period that has most negative correlation coefficient (closest to −1) with SOS (see details in section 2.2).