Interannual and decadal variability of Arctic summer sea ice associated with atmospheric teleconnection patterns during 1850-2017

Abstract The interannual and decadal variability of summer Arctic sea ice is analyzed, using the longest reconstruction (1850-2017) extent available, its relationship with dominant internal variabilities climate system further investigated quantitatively. leading empirical orthogonal function (EOF) mode captures an in-phase fluctuation over Basin. second characterizes a dipolar pattern out-of-phase between Pacific Atlantic Arctic. Summer impacted by major patterns: Multidecadal Oscillation (AMO), North (NAO), (AO), Decadal (PDO) Dipole Anomaly (DA), descending order importance based on multiple regression analyses. five teleconnection patterns accounts for up to 46% total variance in 1 (thermodynamical effect), 30% 2 (dynamical effect). Furthermore, decreased from during 1953-2017 28% 1979-2017, while increased 11% 1979-2017. increasingly greater reduction recent four decades was enhanced positive ice/ocean albedo feedback loop being accelerated amplification, contributed part atmospheric thermodynamical forcing -AO, +NAO, +DA, +AMO, –PDO dynamical transpolar advection outflow driven +DA- +AMO-derived strong anomalous meridional winds. Further analysis, large ensembles simulations single-forcing ensembles, indicates that ice, dominated multidecadal oscillation, partially forced response anthropogenic warming.