Basin have increased winter ventilation in the ocean interior, making this region 46 structurally similar to that of the western Eurasian Basin. The associated enhanced 47 release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to 48 losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in 49 sea-ice cover in the eastern Eurasian Basin. This encroaching "atlantification" of the 50Eurasian Basin represents an essential step toward a new Arctic climate state, with a 51 substantially greater role for Atlantic inflows. 52 53 3 Over the last decade, the Arctic Ocean has experienced dramatic losses of sea-ice loss in 54 the summers, with record-breaking years in 2007 and 2012 for both the Amerasian Basin 55 and the Eurasian Basin (EB). More remarkably, the eastern EB has been nearly ice-free 56 (<10 % ice coverage) at the end of summer since 2011 (Fig. 1). Most sea ice-mass loss 57 results from summer solar heating of the surface mixed layer (SML) through cracks in the 58 ice and open water, and consequent melting of the lower surface of the ice (1-3). Heat 59 advected into the EB interior by Atlantic water (AW) generally has not been considered 60 an important contributor to sea-ice reduction, due to effective insulation of the overlying 61 cold halocline layer (CHL) (4) that separates the cold and fresh SML and pack ice from 62 heat carried by the warm and saline AW. 63There are, however, reasons to believe the role of AW heat in sea-ice reduction is not 64 negligible, and may be increasingly important (5). Nansen (6) warming has slowed slightly since 2008 (Fig. 2c). 74Strong stratification, which is found in most of the Arctic Ocean, prevents vigorous 75 ventilation of the AW. One notable exception is the western Nansen Basin, north and 76 4 northeast of Svalbard, where proximity to the sources of inflowing AW makes possible 77 significant interactions between the SML and the ocean interior (5). Specifically, weakly 78 stratified AW entering the Nansen Basin through Fram Strait is subject to direct 79 ventilation in winter, caused by cooling and haline convection associated with sea ice 80 formation (15). This ventilation leads to the reduction of sea-ice thickness along the 81 continental slope off Svalbard (16, 17). In the past, these conditions have been limited to 82 the western EB, since winter ventilation of AW in the eastern EB was constrained by 83 stronger stratification there. However, newly acquired data show that conditions 84 previously only identified in the western Nansen Basin now can be observed in the 85 eastern EB as well. We call this eastward progression of the western EB conditions the 86 "atlantification" of the EB of the Arctic Ocean. 87 Overview of sea ice state 88The progressive decline in sea ice coverage of the Arctic Ocean during the satellite era, at 89 13.4 % per decade during September (18), has been accompanied by decreases in average 90 sea ice thickness of at least 1.7 m in the central Arctic (19, 20). In the region of t...

[1] To determine whether deep background mixing has increased with the diminishment of the Arctic sea ice, we compare recent internal wave energy and mixing observations with historical measurements. Since 2007, the North Pole Environmental Observatory has launched expendable current probes (XCPs) as a part of annual airborne hydrographic surveys in the central Arctic Ocean. Mixing in the upper 500 m is estimated from XCP shear variance and Conductivity-Temperature-Depth (CTD) derived Brunt-V€ ais€ al€ a frequency. Internal wave energy levels vary by an order of magnitude between surveys, although all surveys are less energetic and show more vertical modes than typical midlatitude Garrett-Munk (GM) model spectra. Survey-averaged mixing estimates also vary by an order of magnitude among recent surveys. Comparisons between modern and historical data, reanalyzed in identical fashion, reveal no trend evident over the 30 year period in spite of drastic diminution of the sea ice. Turbulent heat fluxes are consistent with recent double-diffusive estimates. Both mixing and internal wave energy in the Beaufort Sea are lower when compared to both the central and eastern Arctic Ocean, and expanding the analysis to mooring data from the Beaufort Sea reveals little change in that area compared to historical results from Arctic Internal Wave Experiment. We hypothesize that internal wave energy remains lowest in the Beaufort Sea in spite of dramatic declines in sea ice there, because increased stratification amplifies the negative effect of boundary layer dissipation on internal wave energy.

The properties of a polymeric system are a consequence of the interactions that occur between the various components of these complex systems. These components may vary significantly in terms of chemical nature (e.g. organic/inorganic), physical properties (e.g. particle size, surface area, molecular weight), structural characteristics and proportion in the formulations composition. This review paper addresses the major approaches in use regarding the analysis of the interactions that occur between the polymeric system components and the use of such approaches in the interpretation of the chemical, physical and thermodynamic properties of these systems. Special attention is given to the technique of inverse gas chromatography.A case study is presented, where use was made of inverse gas chromatography to characterize thermodynamically the surface of the major components of pigmented PC/PBT blends. The concept of Lewis acidity/basicity was used in the interpretation of the intermolecular interactions nature and potential in these blends, as encountered in phase separation and phase preferences phenomena and as expressed in the morphology, the physical and the mechanical properties of these commercially important composites. #