Dependence of Present and Future European Temperature Extremes on the Location of Atmospheric Blocking.

The impact of atmospheric blocking on European heat waves (HWs) and cold spells (CSs) is investigated for present and future conditions . A 50-member ensemble of the second generation Canadian Earth System Model is used to quantify the role of internal variability in the response to blocking. We find that the present blocking-extreme temperature link is well represented compared to ERA-Interim, despite a significant underestimation of blocking frequency in most ensemble members. Our results show a strong correlation of blocking with northern European HWs in summer, spring, and fall. However, we also find a strong anticorrelation between blocking and HW occurrence in southern Europe in all seasons. Blocking increases the CS frequency particularly in southern Europe in fall, winter, and spring but reduces it in summer. For the future we find that blocking will continue to play an important role in the development of both CSs and HWs in all seasons.

Pitfalls in diagnosing temperature extremes.

Worsening temperature extremes are among the most severe impacts of human-induced climate change. These extremes are often defined as rare events that exceed a specific percentile threshold within the distribution of daily maximum temperature. The percentile-based approach is chosen to follow regional and seasonal temperature variations so that extremes can occur globally and in all seasons, and frequently uses a running seasonal window to increase the sample size for the threshold calculation. Here, we show that running seasonal windows as used in many studies in recent years introduce a time-, region-, and dataset-depended bias that can lead to a striking underestimation of the expected extreme frequency. We reveal that this bias arises from artificially mixing the mean seasonal cycle into the extreme threshold and propose a simple solution that essentially eliminates it. We then use the corrected extreme frequency as reference to show that the bias also leads to an overestimation of future heatwave changes by as much as 30% in some regions. Based on these results we stress that running seasonal windows should not be used without correction for estimating extremes and their impacts.

Spring frost risk for regional apple production under a warmer climate.

Spring frosts, as experienced in Europe in April 2016 and 2017, pose a considerable risk to agricultural production, with the potential to cause significant damages to agricultural yields. Meteorological blocking events (stable high-pressure systems) have been shown to be one of the factors that trigger cold spells in spring. While current knowledge does not allow for drawing conclusions as to any change in future frequency and duration of blocking episodes due to climate change, the combination of their stable occurrence with the biological system under a warming trend can lead to economic damage increases. To evaluate future frost risk for apple producers in south-eastern Styria, we combine a phenological sequential model with highly resolved climate projections for Austria. Our model projects a mean advance of blooming of -1.6 ± 0.9 days per decade, shifting the bloom onset towards early April by the end of the 21st century. Our findings indicate that overall frost risk for apple cultures will remain in a warmer climate and potentially even increase due to a stronger connection between blocking and cold spells in early spring that can be identified from observational data. To prospectively deal with frost risk, measures are needed that either stabilize crop yields or ensure farmers' income by other means. We identify appropriate adaptation measures and relate their costs to the potential frost risk increase. Even if applied successfully, the costs of these measures in combination with future residual damages represent additional climate change related costs.

In vitro study of ingested coins: leave them or retrieve them?

BACKGROUND: Objects and notably coins are frequently swallowed by children 3 to 5 years old. Precisely how they should be managed after passing the gastroesophageal junction without causing symptoms remains controversial. This study was performed to assess dissolution of specific metals from coins immersed in simulated gastric juice. METHODS: Four types of euro and US coins were immersed in simulated gastric juice for 4, 24, 72, and 120 hours. Six metals were evaluated by inductively coupled plasma-atomic emission spectrometry. Weight loss and corrosive behavior were also determined. RESULTS: After only 4 hours, metals had dissolved from euro (Cu, 2.86-7.85 mg; Ni, 0.23-0.52 mg; Zn, 0.09-0.99 mg; Al, 0.24 mg; Sn, 0.02 mg) and US (Cu, 1.45-6.65 mg; Ni, 0-0.62 mg; Zn, 0-0.14 mg) coins. Their concentrations in simulated gastric juice peaked after 24 to 72 hours (milligrams/hours) in euro (Cu, 218/48; Ni, 82.50/72; Zn, 83.00/72; Al, 14.65/72; Sn, 0.66/72) and US (Cu, 126.50/24; Ni, 88.00/72; Zn, 149.00/24) coins. All coins underwent corrosion and weight loss (by 2.56%-4.8%). CONCLUSIONS: Coins retained in the stomach will release a number of heavy metals well known to cause dose-dependent poisoning. Studies to evaluate their toxicity and absorption are needed to optimize treatment.