Euro-Atlantic weather Regimes in the PRIMAVERA coupled climate simulations: impact of resolution and mean state biases on model performance

• DOI: 10.1007/s00382-020-05271-w
• Publication Date: 2020-05-20T16:52:18Z
• Authors: F. Fabiano; H. M. Christensen; K. Strommen; P. Athanasiadis; A. Baker; R. Schiemann; S. Corti
• Keywords: Atmospheric Circulation; Jet stream; Middle latitudes

Abstract Recently, much attention has been devoted to better understand the internal modes of variability climate system. This is particularly important in mid-latitude regions like North-Atlantic, which characterized by a large natural and intrinsically difficult predict. A suitable framework for studying atmospheric circulation look recurrent patterns, commonly referred as Weather Regimes. Each regime specific large-scale pattern, thus influencing regional weather extremes over Europe. The focus present paper study Euro-Atlantic wintertime Regimes models participating PRIMAVERA project. We analyse here set coupled historical simulations (hist-1950), have performed both at standard increased resolution, following HighresMIP protocol. models’ performance reproducing observed assessed terms different metrics, focussing on systematic biases impact resolution. also connection with Jet Stream latitude blocking frequency North-Atlantic sector. find that—for most models—the patterns are represented higher resolution version, all regimes but NAO-. On other side, no clear seen occurrence persistence. Also, models, tend be more tightly clustered simulations, closely resembling ones. However, horizontal not only factor determining model performance, we some evidence that SSTs mean geopotential field might play role.