The Summer North Atlantic Oscillation, Arctic sea ice, and Arctic jet Rossby wave forcing.

We use Coupled Model Intercomparison Project Phase 6 (CMIP6) coupled and Atmospheric Model Intercomparison Project (AMIP) climate models, dynamical analyses, and observations to investigate interactions between summer Arctic sea ice concentration (SIC) variations and the Summer North Atlantic Oscillation (SNAO). Observations suggest that SIC-SNAO relationships mainly come from the East Siberian to Arctic Canada (ESAC) region where a weak atmospheric jet stream exists in summer. Twelve CMIP6 models with the most realistic atmospheric climatologies over the North Atlantic and Europe agree well with reanalyses on relationships between SIC and Northern Hemisphere atmospheric circulation.

Predictability of European winter 2016/2017.

Winter 2016/2017 was one of the driest on record for central Europe and the United Kingdom. This was the result of blocked atmospheric circulation with high pressure centred over North-West Europe dominating the winter mean circulation pattern. Using large ensembles of simulated winters, we find that the observed winter 2016/2017 circulation was very similar in pattern and strength to the circulation associated with the top 10% of driest Central European winters.

A successful prediction of the record CO rise associated with the 2015/2016 El Niño.

In early 2016, we predicted that the annual rise in carbon dioxide concentration at Mauna Loa would be the largest on record. Our forecast used a statistical relationship between observed and forecast sea surface temperatures in the Niño 3.4 region and the annual CO rise.

Tobacco and alcohol use among firefighters during their first 3 years of service.

Firefighters constitute an understudied occupational group that are exposed to a great deal of occupational stress including potentially traumatic stress. As such, higher prevalence rates of posttraumatic stress disorder (PTSD) and substance use disorders have been observed within this population; however, very little is known about the trajectories of health-risk behaviors among firefighters in response to occupational stress over time. The present study enrolled 322 fire service recruits from 7 urban U.

Erratum: Strong constraints on aerosol-cloud interactions from volcanic eruptions.

This corrects the article DOI: 10.1038/nature22974.

Strong constraints on aerosol-cloud interactions from volcanic eruptions.

Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosol-cloud interactions. Here we show that the massive 2014-2015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud droplets-consistent with expectations-but had no discernible effect on other cloud properties.

An unexpected disruption of the atmospheric quasi-biennial oscillation.

One of the most repeatable phenomena seen in the atmosphere, the quasi-biennial oscillation (QBO) between prevailing eastward and westward wind jets in the equatorial stratosphere (approximately 16 to 50 kilometers altitude), was unexpectedly disrupted in February 2016. An unprecedented westward jet formed within the eastward phase in the lower stratosphere and cannot be accounted for by the standard QBO paradigm based on vertical momentum transport. Instead, the primary cause was waves transporting momentum from the Northern Hemisphere.

Global impacts of the 1980s regime shift.

Despite evidence from a number of Earth systems that abrupt temporal changes known as regime shifts are important, their nature, scale and mechanisms remain poorly documented and understood. Applying principal component analysis, change-point analysis and a sequential t-test analysis of regime shifts to 72 time series, we confirm that the 1980s regime shift represented a major change in the Earth's biophysical systems from the upper atmosphere to the depths of the ocean and from the Arctic to the Antarctic, and occurred at slightly different times around the world. Using historical climate model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and statistical modelling of historical temperatures, we then demonstrate that this event was triggered by rapid global warming from anthropogenic plus natural forcing, the latter associated with the recovery from the El Chichón volcanic eruption.

Regional climate impacts of a possible future grand solar minimum.

Any reduction in global mean near-surface temperature due to a future decline in solar activity is likely to be a small fraction of projected anthropogenic warming. However, variability in ultraviolet solar irradiance is linked to modulation of the Arctic and North Atlantic Oscillations, suggesting the potential for larger regional surface climate effects. Here, we explore possible impacts through two experiments designed to bracket uncertainty in ultraviolet irradiance in a scenario in which future solar activity decreases to Maunder Minimum-like conditions by 2050.

Forecast cooling of the Atlantic subpolar gyre and associated impacts.

Decadal variability in the North Atlantic and its subpolar gyre (SPG) has been shown to be predictable in climate models initialized with the concurrent ocean state. Numerous impacts over ocean and land have also been identified. Here we use three versions of the Met Office Decadal Prediction System to provide a multimodel ensemble forecast of the SPG and related impacts.

Understanding unassisted falls: effects of nurse staffing level and nursing staff characteristics.

Hierarchical Poisson modeling was used to explore hospital and nursing unit characteristics as predictors of the unassisted fall rate. Longitudinal data were collected from 1502 units in 248 US hospitals. The relation between the fall rate and total nurse staffing was positive at lower staffing levels and negative for levels around and above the median.

Aspergillus mastoiditis in a patient with systemic lupus erythematosus: a case report.

Fungal mastoiditis caused by Aspergillus fumigatus predominantly occurs in immunocompromised patients. Invasive temporal bone mycoses are rare. They are usually associated with host immunodeficiency, are difficult to diagnose, and many cases are fatal.

A cadaver model to evaluate the accuracy and reproducibility of plain radiograph step and gap measurements for intra-articular fracture of the distal radius.

Purpose: The purpose of this study was to determine the accuracy and reproducibility of intra-articular step-off and gap displacements measured on plain radiographs using a standard cadaver model.

Methods: Twenty-two physicians, in a blinded randomized fashion using a standard technique, examined the radiographs of 12 unique combinations of step and gap displacement created by a 3-part intra-articular osteotomy of the distal radius. Observer accuracy, inter- and intraobserver agreement, and tolerance limits were calculated.

Central placement of the screw in simulated fractures of the scaphoid waist: a biomechanical study.

Background: Recent reports on internal fixation of acute fractures of the scaphoid waist have demonstrated higher rates of central placement of the screw when cannulated screws were used than when noncannulated screws were used. This cadaveric study was designed to determine whether central placement in the proximal fragment of the scaphoid offers a biomechanical advantage.

Methods: Eleven matched pairs of scaphoids were removed from fresh cadaveric wrists.

Comparison of bipolar scissors and bipolar forceps in tonsillectomy.

Bipolar diathermy scissors tonsillectomy is a relatively new surgical technique. We conducted a prospective study of 90 patients to compare this technique with bipolar forceps tonsillectomy. We found that the use of the bipolar scissors required significantly less operating time (mean: 3.