Exploring and characterizing the life cycles of tracked anticyclones on the northern hemisphere

Summer heat waves are among the most severe natural hazards in the mid-latitudes and known to be strongly associated with anticyclonic activity. Despite their frequent occurrence, gaps remain in the understanding of the processes that drive persistent heat outbreaks during the lifetime and in the vicinity of some anticyclones. A closer look at the life cycles of these anticyclones could be beneficial for understanding the circumstances under which there is an increased likelihood of near-surface extremes.
To date, numerous studies have performed some form of feature tracking on anticyclones, but many are limited to a specific region or context, while those that take a broader view focus on climatology rather than individual life cycles.
In this work, mid-tropospheric anticyclones are identified though geopotential height anomalies, tracked over time and analyzed based on their shape, propagation speed and overlap with other atmospheric phenomena, such as heat waves, droughts and blocking. Using 40 years of northern hemisphere reanalysis data, a detailed track dataset for around 5900 individual anticyclones is examined. It is shown that the most extreme temperature anomalies are systematically more likely to be associated with anticyclones with longer life times. Furthermore there is evidence that the probability for a heat wave maximum is higher in the early and late phases of the anticyclonic life cycles, with the former (latter) being particularly true for shorter-lived (longer-lived) high pressure systems.