Different Atmospheric Circulation Patterns Associated With Heatwaves Over Northeastern Siberia in July and August

ABSTRACT Globally, heatwaves have become more frequent over recent decades. Summer Siberian heatwaves have received less attention, even though ecosystems are vulnerable to high temperatures. This study investigates and compares the atmospheric circulation patterns associated with northeastern Siberian heatwaves in July and August. The results suggest a strong teleconnection between eastern Europe and northeastern Siberia, similar to the British–Okhotsk Corridor pattern, along a strengthened polar jet when frequent heatwaves occur in July. However, this teleconnection is less clear in northeastern Siberia in August due to weak Rossby wave activity linked to the waveguide effect. Instead, the formation of northeastern Siberian heatwaves in August is related to abnormally low pressure over the Arctic, as supported by a linear baroclinic model experiment. Additionally, the abnormally high pressure over northeastern Siberia may influence weather in the northwestern Pacific. These findings enhance the current understanding of summer Siberian heatwaves, suggesting their connection to Arctic atmospheric circulation and their importance for subseasonal weather predictions in the northwestern Pacific.