THE VARIABILITY OF HEAT WAVES AND DRY SPELLS IN THE FLAT AND MONTAINOUS REGIONS OF AUSTRIA

Abstract. Based on quality checked time series of daily maximum temperature and 24h precipitation sums, heat waves at 12 stations up to an elevation of 800m and dry spells at 30 stations up to 3000m in Austria over the past 50 years were calculated and analysed. The analysis of the frequencies of heat waves and dry spells showed very differentiated results, because local environmental effects can partly compensate the given dependence on elevation. Since the 1950ies the number of hot days has increased. The largest increase (~25 days) occurred in regions of lower elevation, but an increase of 1 to 2 days can also be observed at elevations of about 700m above sea level. The variability of the number of dry spells is dependant on the location, on the duration of the period and on the season. Only the autumn season can be seen as consistent for the whole country concerning the decreases in the frequency of occurrence of dry spells lasting almost 10 to 30 days. As a result, the well known “Altweibersommer” is not to happen with the same reliability nowadays than in former times

EXPLORING PAST CLIMATE VARIABILITY IN THE GREATER ALPINE REGION

The presentation discusses the potential, the needs and the state of the art of climate variability data quality and analysis in the instrumental period. The greater alpine region is used as an example. Problems and solutions concerning the non climatic noise in time series is discussed (the homogeneity and outlier problem) and some first results based on the new HISTALP datasets are shown

THE NEW CENTENNIAL SNOW INITIATIVE FOR THE GREATER ALPINE REGION (GAR). STATUS REPORT AND FIRST RESULTS

Snow is a significant element in the climate system and has great impact on ecosystem and economy in the Alps, too. Astonishingly there is still a strong gap between the data potential and the data availability. Caused by the existing deficits we started a digitising, quality evaluation, homogenising and analysing initiative for the Alpine region. For the first time we can present a 21-year (1895-1915) daily, high density dataset that was electronically scanned from historic hydro-yearbooks for recent Austria and additional some surrounding regions in Italy, Slovenia, Croatia and Czech Republic. We hope that our snow initiative will grow to a pan-alpine effort to fill the existing lack of information

A NEW HIGH-RESOLUTION BI-CENTENNIAL (1800–2003) PRECIPITATION DATASET FOR THE GREATER ALPINE REGION

A new precipitation dataset for the Greater Alpine Region (GAR; 4°E–19°E, 43°N–49°N) has been developed. It provides monthly precipitation totals for the 1800–2003 period on a 10-min resolution grid. The new ‘HISTALP 10-min-grid’ dataset is based on long-term homogenized precipitation series from meteorological stations across the study domain and a high-resolution precipitation climatology dataset for the 1971–1990 period. The effective coverage of the dataset depends on the observations available in the station network which progressively decline back to the early 19th Century (from 192 to 5 stations). To aid the use of these data in other studies, an accompanying dataset has also been developed, which provides a measure of quality of each monthly precipitation estimate over the grid: the explained variance, relative to the 1931–2000 (maximum data availability) period. The computed quality score illustrates the comparatively poorer accuracy of the dataset for regions and months with less coherent precipitation fields (i.e., over the Alps and in summer) and when the number of stations is reduced, particularly before 1840. The derived gridded field has been compared with other independently-developed datasets and is found to provide a similar description of the precipitation in the GAR for places and periods of common coverage

PATTERNS OF PRECIPITATION VARIABILITY IN THE GREATER ALPINE REGION

A recently set up and homogenised new precipitation dataset for the Greater Alpine Region (GAR) is presented here with some first preliminary analyses. Climate change patterns within the study region are analysed in terms of regionally different evolutions, seasonality, and short to long-term trends. It will be shown that precipitation presents pronouncedly different variability patterns in space as well as in terms of seasonality and at different time scales

Tree-Ring Amplification of the Early Nineteenth-Century Summer Cooling in Central Europe

Les prokinéticines sont des facteurs angiogènic potentiels qui se liant aux récepteurs couplés aux protéines G (PKR1 et PKR2) pour initier leurs effets biologiques. Nous avons montré que le transfert transitoire du gène PKR1 après ligation de l’artère coronaire réduit la mortalité et préserve la fonction du ventricule gauche en favorisant la néovascularisation et protegé des cardiomyocytes. Nous avons montré que des souris transgéniques (TG) surexprimant PKR1 dans le coeur aucune anomalie spontanée dans les cardiomyocytes, mais on observe une augmentation de néovascularization. Cependant des souris TG surexprimant PKR2 dans le coeur ont montré de l'hypertrophie excentrique et la perméabilité vasculaire. Pour la première fois nous avons montré que la balance entre l'activation de la voie de signalisation de PKR1 et de PKR2 pouvait être très importante pour protéger les cardiomyocytes des lésions causées par l'ischémie et/ou d’induire la neovascularisation dans le coeur.Cardiovascular disease is first cause of mortality worldwide. Prokineticins are potent angiogenic factors that bind to two G protein-coupled receptors (PKR1 and PKR2) to initiate their biological effects. We showed that transient PKR1 gene transfer after coronary ligation reduces mortality and preserves left ventricular function by promoting neovascularization and protecting cardiomyocytes. Next we showed that transgenic (TG) mice overexpressing PKR1 in heart exhibit neovascularization without inducing any spontaneous pathology in cardiomyocytes. However TG mice overexpressing PKR2 in heart exhibit eccentric hypertrophy in cardiomyocyte and vascular leakage. As a conclusion, for the first time we have shown that the balance between the activation of PKR1 and PKR2 signaling could be very important to prevent cardiomyocytes from ischemic insult and/or to induce neovascularization in heart

Benchmarking homogenization algorithms for monthly data

The COST (European Cooperation in Science and Technology) Action ES0601: Advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies. The algorithms were validated against a realistic benchmark dataset. Participants provided 25 separate homogenized contributions as part of the blind study as well as 22 additional solutions submitted after the details of the imposed inhomogeneities were revealed. These homogenized datasets were assessed by a number of performance metrics including i) the centered root mean square error relative to the true homogeneous values at various averaging scales, ii) the error in linear trend estimates and iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that currently automatic algorithms can perform as well as manual ones

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference