Cold extremes in North America vs. mild weather in Europe: the winter 2013/2014 in the context of a warming world
Post date: Jan 5, 2015 10:19:00 AM
We all know that temperatures vary on a range of time and spatial scales. Well known examples are the daily and seasonal cycles, associated with the amount of incoming solar radiation. When averaged over an entire season (for example the winter), variations are also observed. In a gradually warming world the winters get milder, but superposed on this "trend" a considerable amount of variability occurs: every winter is different. Why? One of the reasons is that the circulation is an important driver of temperature variability. In this way it can happen (and in fact it does happen) that the large-scale circulation patterns may lead to record-cold conditions in some regions, while leading to record-mild conditions in other places. We have analysed this for the winter 2013/2014, which for the Netherlands was characterized by a complete absence of Hellmann-days (days where mean daily temperature is below freezing), while on "the other side of the lake" it was seemingly very cold in the US. But how exceptional were the winters and does climate change play any role in this? This is where the paper is all about. And it is out now in early online press with BAMS (Bulletin of the American Meteorological Society). The abstract is given below as well as one of the figures. Click on the abstract to go the paper. E-mail me if you can not access it.
Caption: Fig. 2d from the paper. Data: climate explorer.