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The January 2017 wintry weather spread over the south‐eastern Europe and Turkey ‐which led to extremely low temperatures (−40°C) and snowstorms. This study strived to draw together key prominent dynamical mechanisms governing seasonal temperature variability in a warming climate, which can serve as a recognizable flow pattern and yield insights into their most important triggering mechanisms and maintenance. The connection between cold spells and atmospheric blocking was elucidated by utilizing an objective cold‐wave indicator and a two‐dimensional blocking indicator. The cold‐wave indicator ‐which uses a non‐parametric approach to diagnose a spatiotemporally varying minimum temperature threshold‐ gave an objective account of cold spells of January 2017. An analysis of cold‐wave activities indicated that parts of Europe and Turkey went through very cold weather conditions for approximately 7–12 days. Cold spells were closely related to the position of the blocking and the 500 hPa geopotential height anomalies. The horizontal distribution of surface temperature anomalies indicated that associated temperature anomalies were quite large in the south‐eastern Europe and Turkey. The persistence of the anticyclone over the eastern Atlantic steered the low pressure system towards the south‐eastern Europe and Turkey. The collocation of prominent atmospheric patterns led to the formation of extreme cold spells. Our results of two‐dimensional atmospheric blocking index revealed that blocking lasted for 5 days over the eastern Atlantic ‐which enabled anticyclonic conditions persisting. Diagnostics indicate that the imposed blocking over the north‐east Atlantic alters the direction and strength of the zonal flow in the south‐eastern Europe, which influences the behaviour of synoptic‐scale flow in its downstream. These results are consistent with the inferences drawn from surface temperature analyses, which accentuate the role of blocking imposed circulation on the anomalous low temperature anomalies. Characteristics of blocking at the north‐eastern Atlantic shed light on the winter climate variability over Europe and Turkey. [ABSTRACT FROM AUTHOR]

It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) for northern growing areas requires cold tolerance for extending the vegetative period. Our objectives were to evaluate two large panels of maize inbred lines adapted to Europe for cold tolerance and to estimate the effects of cold-related traits on biomass production. Two inbred panels were evaluated for cold tolerance per se and in testcrosses under cold and control conditions in a growth chamber and under field conditions. Comparisons of inbreds and groups of inbreds were made taking into account the single nucleotide polymorphisms (SNP)-based genetic structure of the panels, and the factors affecting biomass production were studied. Eight flint and one dent inbred with diverse origins were the most cold tolerant. The most cold-tolerant dent and flint groups were the Iodent Ph207 and the Northern Flint D171 groups, respectively. The relationships between inbred per se and testcross performance and between controlled and field conditions were low. Regressions with dry matter yield in the field as dependent variable identified plant height (R² = 0.285) as the main independent variable, followed by quantum efficiency of photosystem II (R² = 0.034) and other traits with minor contributions. Cold-tolerance- related traits had low and negative effects on dry matter yield. Models intending the prediction of final performance from traits scored in early developmental stages are not expected to be precise enough for breeding. For improving cold tolerance, inbreds released from crosses among the No Iodent group and the Northern Flint group may show high combining ability, as well as between both groups and the Northern Flint D171 group. [ABSTRACT FROM AUTHOR]

This paper describes seasonal peculiarities of modern climate warming in the European region. It is shown that warming scenarios considerably differ in cold and warm periods of the year. The warming is accompanied with growth and considerable change in the phase of the yearly cycle in solarity data. A strong half-year cycle is recognized in seasonal variation of long-term trends over the last few years. Peculiarities of climate change in Europe and the increased influence of the tropics are discussed in view of the results obtained. [ABSTRACT FROM AUTHOR]

Atmospheric blocking is an important source of low-frequency variability. We apply a blocking detection and tracking method to ERA-40 data for the Atlantic-European region to assess linkages to extreme events, that is, cold and dry spells in the extended winter season (November-April). The method is feature-oriented, identifies 500-hPa geopotential height maxima, and connects them with a next-neighbourhood search in time. The analysis reveals a statistically significant decrease of number of blocking events over the period of ERA-40. Winters with an increased number of blocking events are associated with negative temperature anomalies over Central to Eastern Europe and dryer conditions, whereas Southern Europe experiences warmer and wetter conditions during such episodes. Using extreme value statistics we show evidence that cold spells, and to some extent dry spells, are strongly associated with extremes in blocking frequency. The number of cold spell days increases with the duration of blocking events indicating that cold spells need time to establish during blocking events, thus return periods of cold spells are longer than those for blocking events. This behaviour is not found for the relation of dry spells with blocking events. Still, blocking episodes have a higher occurrence of dry spells than climatology. [ABSTRACT FROM AUTHOR]

The article discusses the so-called Little Ice Age in Europe and its effect on agriculture. Specifically focused on is the crisis of the year 1570, which was preceded by an extremely cold and long winter during 1568 and 1569 in Central Europe and resulted in subsequent damp seasons and poor harvests, as well as frozen rivers and flooding. Contemporary source documents on weather, failed harvests, hunger, and poverty during the era are cited. Climate change in the decades after 1570 is also traced, and statistics on rising grain prices are related to those changes.

A major perceived cost of migration in birds is the associated mortality. This mortality has proved difficult to measure and separate from mortality during stationary periods of the annual cycle. This paper reviews some major recorded mortality incidents among migratory birds attributed to inclement weather and other factors, including: (1) in-flight losses, caused by storms and other adverse weather en route, usually over water; (2) unseasonable cold weather soon after arrival in breeding areas; and (3) unseasonable cold weather before departure from breeding areas. Cold weather often kills migrants in their breeding areas, but not the local resident species which can better withstand it at those times. For migrants, cold and snow act to cut off the food supply, and can have a major selective effect on the seasonal timing of migration. Records of in-flight weather-induced mortality, involving up to hundreds or thousands of birds at a time, have affected mainly small passerines, but also larger birds, including eagles and swans. Most occurred in conditions of mist, rain or snow storms, and some involved nocturnal collisions with illuminated masts and other tall structures. Records of post-arrival mortality in breeding areas have involved mainly small insectivores (especially hirundines), but also waders and waterfowl. Such incidents, associated with cold and snow, have reduced local breeding densities from the previous year by 25–90%, depending on species and area, with up to several years required for recovery. Records of pre-departure mortality on breeding areas have mainly affected hirundines. Two major incidents in central Europe in September 1931 and 1974 killed hundreds of thousands, or even millions, of swallows and martins. After the latter incident, House Martin Delichon urbicum populations in Switzerland the following year were reduced by an estimated 25–30%. Such climatic extremes that occurred in spring or late summer in particular parts of the breeding range have been recorded at approximate mean frequencies of 2–10 per century. Average daily mortality in many bird species can clearly be much greater during migration periods than during stationary periods. Despite the heavy losses of birds on migration, it may be assumed that migration persists in the long term because the fitness costs (in terms of associated mortality) are more than offset by the fitness benefits (in terms of improved overall survival and breeding success) that accrue from migration. [ABSTRACT FROM AUTHOR]

Weather-related health effects have attracted renewed interest because of the observed and predicted climate change. The authors studied the short-term effects of cold weather on mortality in 15 European cities. The effects of minimum apparent temperature on cause- and age-specific daily mortality were assessed for the cold season (October–March) by using data from 1990–2000. For city-specific analysis, the authors used Poisson regression and distributed lag models, controlling for potential confounders. Meta-regression models summarized the results and explored heterogeneity. A 1°C decrease in temperature was associated with a 1.35% (95% confidence interval (CI): 1.16, 1.53) increase in the daily number of total natural deaths and a 1.72% (95% CI: 1.44, 2.01), 3.30% (95% CI: 2.61, 3.99), and 1.25% (95% CI: 0.77, 1.73) increase in cardiovascular, respiratory, and cerebrovascular deaths, respectively. The increase was greater for the older age groups. The cold effect was found to be greater in warmer (southern) cities and persisted up to 23 days, with no evidence of mortality displacement. Cold-related mortality is an important public health problem across Europe. It should not be underestimated by public health authorities because of the recent focus on heat-wave episodes. [ABSTRACT FROM AUTHOR]