Sack Lunch Seminar (SLS)

There is considerable interest in determining how the full distribution of surface temperature changes with warming. Model ensembles project that extratropical land temperature variability will decrease in the future, consistent with simple physical arguments related to polar amplification. However, observational studies have thus far come to conflicting conclusions. Several analytical pitfalls in interpreting observational records lead to these discrepancies, and highlight the importance of accounting for non-normality and the effects of filtering, time-averaging, gridding, and smoothing. I will present a set of methods designed to overcome these challenges, which I apply to a large set of daily temperature observations to show that a decrease in temperature variability is already robustly detectable in the extratropics.