2024 Summer Heat in Svalbard: Atmospheric & Marine Drivers Behind Extreme Temperatures

The Svalbard archipelago in the high Arctic is one of the fastest warming regions on Earth, warming approximately five times faster than the global average. The most dramatic warming in recent decades has been observed in the coldest months, that occur during the winter and early spring. Despite an evident warming trend, the warming in summer has been less pronounced. Still, recent summers have also seen increasingly frequent and extreme warm anomalies, with 2024 being the third consecutive record warm summer. During this summer, both seasonal and monthly summer temperature records were shattered by exceptional margins at various weather stations across the archipelago. We present the atmospheric drivers behind these extreme conditions, with focus on the warmest month in Svalbard’s measurement history: August 2024.

Synoptic analyses, based on ERA5 and ORAS5 reanalysis products and LAGRANTO (Sprenger & Wernli, 2015) back trajectories reveal an unusual persistence of pressure systems and an exceptionally strong and persistent southerly flow. Sea surface temperatures were exceptionally high too, both amplifying and being amplified by the synoptic heat transport. Together, these conditions sustained pronounced warmth over the region far beyond what would be expected from the long-term warming trend alone.

These findings highlight the importance of atmospheric circulation, persistence of weather and ocean–atmosphere interactions in driving extreme Arctic summer temperatures. Accordingly, we recommend research to the potential increase in persistence of summer weather at high latitudes, the extreme events it may cause, and the consequences thereof.

Sprenger, M., & Wernli, H. (2015). The LAGRANTO Lagrangian analysis tool–version 2.0. Geoscientific Model Development, 8(8), 2569-2586.