North Atlantic atmospheric and ocean inter-annual variability over the past fifty years – Dominant patterns and decadal shifts

A new collective view of oceanography of the Arctic and North Atlantic basins

“…They also document decadal and multidecadal changes in the frequency of occurrence of atmospheric states, typically referred to as atmospheric circulation regimes (Molteni et al, 2006). The authors (Hauser et al, 2015) demonstrate, in particular, that the strong upward trend in the NAO index observed in the late 1980s and early 1990s (Hurrell and van Loon, 1997) was associated with a multidecadal shift in the frequency distributions of the dominant atmospheric circulation regimes over the North Atlantic (see Fig. 21 by Hauser et al, 2015).…”

“…The authors (Hauser et al, 2015) demonstrate, in particular, that the strong upward trend in the NAO index observed in the late 1980s and early 1990s (Hurrell and van Loon, 1997) was associated with a multidecadal shift in the frequency distributions of the dominant atmospheric circulation regimes over the North Atlantic (see Fig. 21 by Hauser et al, 2015). The period after the mid-1980s was characterized by strong positive NAO and cold winters between the late 1980s and early 1990s (e.g., Figs.…”

“…This Special Issue focuses on the historical framework and recent advances in the understanding of the physical oceanography of the North Atlantic, including Mediterranean Sea, Nordic and Barents Seas, and of the Arctic Ocean. The issue presents the major results of studying the long-term variability of atmospheric forcing (Hauser et al, 2015), and the characteristics of the ocean response to the climate change in the SPNA (Hauser et al, 2015;Kieke and Yashayaev, 2015;Fischer et al, 2015;Mercier et al, 2015;Desbruyères et al, 2015;Wang et al, 2015), Nordic Seas (Yashayaev and Seidov, 2015;Seidov et al, 2015), Arctic Ocean (Rudels, 2015;Rudels et al, 2015;Seidov et al, 2015;Yashayaev and Seidov, 2015) and Mediterranean Sea (Pinardi et al, 2015;Houpert et al, 2015). Two articles (Hu et al, 2015;Sevellec and Fedorov, 2015) focus on the AMOC and on various processes in the Arctic and SPNA connected to its functionality.…”

“…To the contrary, it is highly variable, tending to change its phase from one month to another, and its longer-term time-average behavior reflects the combined effect of residence time in any given phase and its amplitude therein.' ' Hauser et al (2015) study the relationship between the longterm NAO-related variability in atmospheric forcing and oceanographic characteristics over the past fifty years. They also document decadal and multidecadal changes in the frequency of occurrence of atmospheric states, typically referred to as atmospheric circulation regimes (Molteni et al, 2006).…”

“…The processes within each component of the climate system are determined by the specific properties and nonlinear dynamics of each component and, at the same time, are strongly influenced by the interactions with other components as well as by radiative forcing from outside of the climate system. The Earth's climate is a nonlinear dynamical system that is inherently multi-scale with large numbers of degrees of freedom and complex interaction between its elements (Palmer, 1999;Hauser et al, 2015). In many instances, the stories of the long-term (decades and longer) climate changes are mostly drawn on the oceans' canvas.…”