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The northern limb of the Atlantic thermohaline circulation and its transport of heat and salt towards the Arctic strongly modulate the climate of the Northern Hemisphere. The presence of warm surface waters prevents ice formation in parts of the Arctic Mediterranean, and ocean heat is directly available for sea-ice melt, while salt transport may be critical for the stability of the exchanges. Through these mechanisms, ocean heat and salt transports play a disproportionally strong role in the climate system, and realistic simulation is a requisite for reliable climate projections. Across the Greenland-Scotland Ridge (GSR) this occurs in three well-defined branches where anomalies in the warm and saline Atlantic inflow across the shallow Iceland-Faroe Ridge (IFR) have been shown to be particularly difficult to simulate in global ocean models. This branch (IF-inflow) carries about 40% of the total ocean heat transport into the Arctic Mediterranean and is well constrained by observation during the last 2 decades but associated with significant interannual fluctuations. The inconsistency between model results and observational data is here explained by the inability of coarse-resolution models to simulate the overflow across the IFR (IF-overflow), which feeds back onto the simulated IFinflow. In effect, this is reduced in the model to reflect only the net exchange across the IFR. Observational evidence is presented for a substantial and persistent IF-overflow and mechanisms that qualitatively control its intensity. Through this, we explain the main discrepancies between observed and simulated exchange. Our findings rebuild confidence in modelled net exchange across the IFR, but reveal that compensation of model deficiencies here through other exchange branches is not effective. This implies that simulated ocean heat transport to the Arctic is biased low by more than 10% and associated with a reduced level of variability, while the quality of the simulated salt transport becomes critically dependent on the link between IF-inflow and IF-overflow. These features likely affect sensitivity and stability of climate models to climate change and limit the predictive skill. [ABSTRACT FROM AUTHOR]

Throughout much of the Quaternary Period, inhospitable environmental conditions above the Arctic Circle have been a formidable barrier separating most marine organisms in the North Atlantic from those in the North Pacific. Rapid warming has begun to lift this barrier, potentially facilitating the interchange of marine biota between the two seas. Here, we forecast the potential northward progression of 515 fish species following climate change, and report the rate of potential species interchange between the Atlantic and the Pacific via the Northwest Passage and the Northeast Passage. For this, we projected niche-based models under climate change scenarios and simulated the spread of species through the passages when climatic conditions became suitable. Results reveal a complex range of responses during this century, and accelerated interchange after 2050. By 2100 up to 41 species could enter the Pacific and 44 species could enter the Atlantic, via one or both passages. Consistent with historical and recent biodiversity interchanges, this exchange of fish species may trigger changes for biodiversity and food webs in the North Atlantic and North Pacific, with ecological and economic consequences to ecosystems that at present contribute 39% to global marine fish landings. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to estimate the prevalent use of drugs targeting obstructive lung diseases among adults aged 50 or above in Greenland and to assess the use of spirometry testing among these medication users., Study Design: Observational cross-sectional study based on reviews of electronic medical records., Methods: The study was performed in the 6 largest primary healthcare clinics in Greenland, representing approximately 67.0% of the population in Greenland. Adults aged 50 years or above, who had at least one electronically prescribed drug targeting obstructive lung diseases within a 15-month time interval, were identified. We assessed whether a spirometry test was registered in their medical records within previous 2- and 4-year periods., Results: A total of 565 persons were identified. This corresponds to a prevalent medication use of 6.1% (565/9,023) among adults aged 50 years or above. Among these medication users, 14.1% (80/565) had a spirometry test performed within 2 years. Within the 4-year period this increased to 17.9% (101/565)., Conclusion: The use of medication targeting obstructive lung diseases in Greenland among adults aged 50 years or above is common. However, spirometry testing among medication users is low and interventions aiming to increase focus on spirometry testing should be integrated in the primary healthcare system.