The role of the North Atlantic Oscillation for projections of winter mean precipitation in Europe

Abstract

The North Atlantic Oscillation (NAO) is the dominant mode of atmospheric circulation variability in the North Atlantic sector and exerts a strong influence on European winter weather and climate (Hurrell et al., 2003). A positive NAO phase is associated with a stronger North Atlantic eddy-driven jet stream and a northward displaced storm track. In winter, this brings mild and wet weather to northern Europe, and cold and dry weather to southern Europe.The NAO is associated with the leading mode of interannual variability in European winter precipitation (Álvarez-García et al., 2019;Qian et al., 2000;Seager et al., 2020;Zveryaev, 2006) and can have significant societal impacts. For example, on interannual timescales the NAO influences precipitation and river flows in the Iberian Peninsula, with consequences for water availability for hydroelectricity production and intensive agriculture (Trigo et al., 2004). Prolonged winter periods with a predominantly positive NAO state are also connected to the occurrence of catastrophic flood events in northern Europe, with significant impacts on flood economic losses (Zanardo et al., 2019).On longer timescales, climate models generally project an increase in the winter NAO index by the late 21st century under a high-emissions scenario (

Active around the year: Butterflies and moths adapt their life cycles to a warming world

“…Annual mean temperatures are increasing and extreme weather conditions occur more frequently (McKenna & Maycock, 2022;Rumpf et al, 2022;Van Der Wiel et al, 2023). Summers are becoming hotter and drier, winters wet and mild (Christidis & Stott, 2021).…”