Rüdiger Glaser

Variations in Reconstructed Ice Winter Severity in the Western Baltic from 1501 to 1995, and their implications for the North Atlantic Oscillation

Variations in ice winter severity in the Western Baltic between 1501 and 1995 were investigated using an index time series derived from classified values of accumulated areal ice volume along the German Baltic coast, the time series back to 1701, having been extended to the beginning of the 16th century. When compared with the 1501–1995 mean, the Gaussian lowpass-filtered time series of the ice winter index numerals with a 40-year cutoff period shows increased severity (strong phases) in 1554–1576, 1593–1630, 1655–1710, and 1763–1860, while periods of decreased severity occurred in 1501–1553, 1577–1592, 1631–1654, 1711–1762, and from 1861 to the present. During the latter part of the ‘Little Ice Age’, especially during the 1655–1710 and 1763–1860 phases, the lowpass-filtered time series lay more than half a standard deviation above the arithmetic mean of the reference period 1901–1960, representing the present regime, for more than three decades. Between 1501 and 1860, the ice winter severity in the Western Baltic fluctuated around a level 55% higher than that during the present period. Using the contingency table published by Koslowski and Loewe, the frequency of events of weak westerly flow above the northeastern North Atlantic during the ‘Little Ice Age’ was estimated. The calculated values of weak westerly flow expected per decade suggest that strong phases of increased ice winter severity were characterized by frequent blocking situations (weak westerly flow), and that, contrarily, the weak phases of reduced ice winter severity between about 1575 and 1860 may be regarded as phases of increased zonal circulation.

Seasonal Temperature and Precipitation Fluctuations in Selected Parts of Europe During the Sixteenth Century

The article in hand presents a comparative analysis of unweighted thermic and hygric index series of different European regions (northern Switzerland, Germany, the Czech Republic, northern Italy, ancient Hungary, Poland and Spain). Besides methodological aspects about the formation of indices, especially the progress as well as the question of similarity development of these series in the 16th century are discussed and shown on the balance sheet. It becomes evident that with respect to the temperature on the level of unweighted indices the European regions of Germany, the Czech Republic and Switzerland are very similar during all seasons. In winter and summer these correlations are especially evident, during the transitional seasons they are smaller. Larger differences exist between the central European core region and the adjacent areas of research. In principle, the hygric differences are larger than the thermic ones.In the course of the sixteenth century marked cooling phases occurred during all seasons with increasing accentuation. These phases were typical for the climate of the Little Ice Age. In addition to this long-term analysis, some outstanding years of extreme weather like those of 1540, 1573 and 1587 are presented, in the course of which questions of climatic impact are included. Finally, recent instrumental data was used to conduct an analysis that compared the similarities between the respective regions and the similarities between the empirical data and indices. On the one hand, this confirmed the spatial pattern, on the other hand the usability of the indices.

Spatial Distribution of, and Risk Factors for, Opisthorchis viverrini Infection in Southern Lao PDR

Background Opisthorchis viverrini is a food-borne trematode species that might give rise to biliary diseases and the fatal cholangiocarcinoma. In Lao PDR, an estimated 2.5 million individuals are infected with O. viverrini, but epidemiological studies are scarce and the spatial distribution of infection remains to be determined. Our aim was to map the distribution of O. viverrini in southern Lao PDR, identify underlying risk factors, and predict the prevalence of O. viverrini at non-surveyed locations. Methodology A cross-sectional parasitological and questionnaire survey was carried out in 51 villages in Champasack province in the first half of 2007. Data on demography, socioeconomic status, water supply, sanitation, and behavior were combined with remotely sensed environmental data and fed into a geographical information system. Bayesian geostatistical models were employed to identify risk factors and to investigate the spatial pattern of O. viverrini infection. Bayesian kriging was utilized to predict infection risk at non-surveyed locations. Principal Findings The prevalence of O. viverrini among 3,371 study participants with complete data records was 61.1%. Geostatistical models identified age, Lao Loum ethnic group, educational attainment, occupation (i.e., rice farmer, fisherman, and animal breeder), and unsafe drinking water source as risk factors for infection. History of praziquantel treatment, access to sanitation, and distance to freshwater bodies were found to be protective factors. Spatial patterns of O. viverrini were mainly governed by environmental factors with predictive modeling identifying two different risk profiles: low risk of O. viverrini in the mountains and high risk in the Mekong corridor. Conclusions/Significance We present the first risk map of O. viverrini infection in Champasack province, which is important for spatial targeting of control efforts. Infection with O. viverrini appears to be strongly associated with exposure to the second intermediate host fish, human behavior and culture, whereas high transmission is sustained by the lack of sanitation.

The year-long unprecedented European heat and drought of 1540 – a worst case

The heat waves of 2003 in Western Europe and 2010 in Russia, commonly labelled as rare climatic anomalies outside of previous experience, are often taken as harbingers of more frequent extremes in the global warming-influenced future. However, a recent reconstruction of spring–summer temperatures for WE resulted in the likelihood of significantly higher temperatures in 1540. In order to check the plausibility of this result we investigated the severity of the 1540 drought by putting forward the argument of the known soil desiccation-temperature feedback. Based on more than 300 first-hand documentary weather report sources originating from an area of 2 to 3 million km2, we show that Europe was affected by an unprecedented 11-month-long Megadrought. The estimated number of precipitation days and precipitation amount for Central and Western Europe in 1540 is significantly lower than the 100-year minima of the instrumental measurement period for spring, summer and autumn. This result is supported by independent documentary evidence about extremely low river flows and Europe-wide wild-, forest- and settlement fires. We found that an event of this severity cannot be simulated by state-of-the-art climate models.

Reconstruction of the ice winter severity since 1701 in the Western Baltic

AbstractThis reconstruction of the ice winter severity in the Western Baltic is based for the period 1878-1993 on the accumulated areal ice volume along the German Baltic coast with observations from 13 coastal stations; for the period 1701-1877 it is based on the accumulated areal ice volume divided into 7 classes (ice winter severity types). The various types of data consulted in the latter case provided ice data of good spatial and temporal resolution.Speerschneiders compilation of data relating to ice conditions in Danish Baltic waters was found to be a valuable source of information. Using a classification table for the periods 1907-1943 and 1947-1992, five of the seven ice winter types have been derived with certainty as they are characterized by typical stages of maximum ice cover throughout the Western Baltic.The Gaussian lowpass-filtered time series of the ice winter index numerals with a 20 year cutoff period shows four periods of varying ice winter severity over a secular range: 1701-1720: slightly increased ice winter severity with regard to the mean of the 1701-1993 time series; this period can be assigned to the end of a cooling phase during ‘Little Ice Age’ which in central Europe peaked in the second half of the 17th c. 1721-1760: ice winter severity is clearly reduced in this period. 1761-1860: ice winter severity is clearly increased (maximum occurs around 1800) towards the end of the ‘Little Ice Age’, associated with increased variability of ice production. 1861-1993: the present-day ice winter regime when three short intervals with increased ice winter severity (the 1890s, 1940s and 1980s) and a period of greatly reduced ice winter severity (between 1900 and the mid-1920s) stand out.

Hydrometeorological reconstruction of the 1824 flood event in the Neckar River basin (southwest Germany)

Abstract The integration of extreme historical floods in contemporary flood protection contributes towards improved risk management and safer handling of floods in the future. As a case study within the “Xfloods” project at the University of Freiburg (Germany), the discharges of the extreme flood in 1824 in the Neckar River basin (Baden-Württemberg/southwest Germany) were reconstructed using historical data. Quantitative and qualitative historical sources were applied to model the regional atmospheric circulation pattern, the weather conditions and the precipitation distribution associated with the event. Discharges were simulated using the water-balance model LARSIM (Large Area Runoff Simulation Model), the operational flood forecasting model in Baden-Württemberg. The developed methodology shows potential for wider use in assessing extreme historical floods and for application to contemporary flood management.

Mapping atmospheric corrosion in coastal regions: methods and results

Corrosion can seriously affect the service life of components for solar energy con- version. We present results of mapping the potential of atmospheric corrosion in coastal regions with the aid of a Geographical Information System (GIS). Concentration of sea salt aerosols, which are the main atmospheric pollutants in maritime coastal regions, gives an indication of the probability of the atmospheric corrosion leading to PV-module degradation. Two approaches to estimate the distribution of sea salt aerosol across the coastal regions worldwide are investigated. The first approach is a geo-statistical analysis that has been used for interpolating chloride deposition data. The second approach is based on modeling the environmental conditions, which are affecting source and distribution of airborne salinity. The comparison of these two approaches provides high accuracy in the description of the variation in airborne salinity across the coastal regions. The assessment of the atmospheric corrosion in coastal regions is based on the international standard ISO 9223. The corrosivity classification is simply defined by three parameters: SO2 pollution, airborne salinity, and relative humidity. A combination of the results from the geo-statistical approach and modeling is used; the result is a map of atmospheric corrosion in coastal regions.

Tree-rings and people – different views on the 1540 Megadrought. Reply to Büntgen et al. 2015

Buntgen et al. (2015; hereinafter B15) present the result of new research which question the results of Wetter et al. 2014, (hereinafter W14) and Wetter et al. (2013, hereinafter W13)regarding European climate in 1540. B15 conclude from tree-ring evidence that the results based on documentary data of W14 probably overstated the intensity and duration of the 1540 drought event. W14 termed it Megadrought because of its extreme duration and spatial extent compared to other drought events in central Europe, although they note that the term is generally used for decadal rather than for single-year droughts (Seneviratne et al. 2012). We take the opportunity to recall the following issues. Firstly, when dealing with drought the complexity of this phenomenon should be kept in mind. Meteorological drought defined as a large negative precipitation anomaly during a certain period can trigger agricultural, hydrological, groundwater and socioeconomic droughts. Lloyd-Hughes (2013] and references cited herein) concluded that any workable objective definition of drought does not exist. To quantify droughts, various indices based on precipitation, temperature and evapotranspiration are used such as the Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Z-index and PDSI. Their calculation depends on different periods (seasons, combination of months) and so different indices may classify the same drought episode differently (e.g. Brazdil et al.2014).

Food coping strategies in northern Ghana. A socio-spatial analysis along the urban–rural continuum

BackgroundFood insecurity is a worrying challenge worldwide, with sub-Sahara Africa most affected. Literature reveals that in developing countries, food insecurity is a largely ‘‘managed process’’, meaning people are active participants in responding to the risks they face in life. This paper focuses on how households cope with food shortages and how these food coping strategies vary along the urban–rural continuum. A transect approach was used to guide data collection in and around the city of Tamale in northern Ghana. A total of 19 Focus Group discussions, having eight participants each (four women, four men), were conducted between March and May 2014. Additionally, three qualitative in-depth interviews were also conducted, one each in the urban, periurban and rural area.ResultsIn periurban and rural areas, gathering of wild food and selling of charcoal was widely practised, while in urban areas, most households tended to reduce the number of meals as a more frequent coping strategy. The study identified five coping strategies along the urban–rural continuum as the most severe in times of food insecurity, namely skipping a whole day without food, borrowing, buying food on credit, consuming seed stock and restricting adult intake in favour of children. Hunting, consuming less preferred food, taking occasional jobs and engaging in small trading were considered as not severe.ConclusionsStudy results reveal that food coping strategies vary from one spatial entity to another in terms of frequency, severity and coping strategy indices along the urban–rural continuum. This information is useful for indicators to predict crisis (early warning), to understand shortfalls in access to adequate food (assessment), to allocate resources (targeting) or to track the impact of interventions (monitoring and evaluation).

Women’s dietary diversity scores and childhood anthropometric measurements as indices of nutrition insecurity along the urban-rural continuum in Ouagadougou, Burkina Faso

Background Malnutrition is still prevalent worldwide, and its severity, which differs between regions and countries, has led to international organisations proposing its inclusion in the global development framework that will succeed the Millennium Development Goals (post-2015 framework). In Sub-Saharan Africa, malnutrition is particularly severe, among women and children under 5 years. The prevalence of malnutrition has been reported worldwide, differing from region to region and country to country. Nevertheless, little is known about how malnutrition differs between multiple locations along an urban–rural continuum. Objective A survey was carried out in and around Ouagadougou, Burkina Faso, between August and September 2014 to map household nutrition insecurity along the urban–rural continuum, using a transect approach to guide the data collection. Design Transects of 70 km long and 2 km wide directed radially from the city centre outwards were laid, and data were collected from randomly selected households along these transects. Womens dietary diversity scores (WDDSs) were calculated from a sample of 179 women of reproductive age (15–49 years) from randomly selected households. Additionally, anthropometric data (height/length and weight) of 133 children under 5 years of age were collected along the same transects for the computation of anthropometric indices. Results We found that relative proportions of the nutrition indices such as stunting, wasting and underweight varied across the urban–rural continuum. Rural households (15%) had the highest relative proportion of WDDS compared with urban households (11%) and periurban households (8%). There was a significant association between children under 5 years’ nutritional status (wasting, stunting and underweight) and spatial location (p=0.023). The level of agricultural activities is a possible indicator of wasting in children aged 6–59 months (p=0.032). Conclusion Childhood undernutrition certainly has a spatial dimension that is highly influenced by the degree of urbanity, which should be taken into consideration in policy formulation and implementation.