| Type | Journal Article |
|---|---|
| Author | Pascale Affolter |
| Author | Ulf Büntgen |
| Author | Jan Esper |
| Author | Andreas Rigling |
| Author | Pascale Weber |
| Author | Jürg Luterbacher |
| Author | David Frank |
| URL | http://link.springer.com/article/10.1007/s10342-009-0327-x |
| Volume | 129 |
| Issue | 3 |
| Pages | 289-298 |
| Publication | European Journal of Forest Research |
| ISSN | 1612-4669, 1612-4677 |
| Date | 2010/05/01 |
| Journal Abbr | Eur J Forest Res |
| DOI | 10.1007/s10342-009-0327-x |
| Accessed | 7. duben 2014 13:52:52 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | Tree rings from the Alpine area have been widely used to reconstruct variations in summer temperature. In contrast, estimates of changes in the hydrological cycle are rather scarce. In order to detect altitudinal and species-specific patterns of growth responses to anomalous dry and wet conditions, a large network of 53 tree-ring width site chronologies along the Rhone valley (Valais, Switzerland) covering the 1751–2005 period was compiled and analyzed. A total of 1,605 measurement series from four conifer species—pine, larch, spruce, fir—were detrended to allow inter-annual to multi-decadal scale variability to be preserved. Site chronologies were combined to four altitudinal (colline: <800 m asl, sub-montane: 800–1,000 m asl, montane: 1,000–1,450 m asl, sub-alpine: >1,450 m asl) and species-specific mean time-series. These records were compared with temperature, precipitation, and drought (scPDSI) data. Among the altitudinal records, the colline chronologies showed highest correlation with June precipitation and scPDSI (0.5 and 0.7). Altitudinal effects, via control on climatic conditions, were superimposed upon species-specific characteristics in affecting tree growth and response to moisture variations. In particular, species-specific differences affected the significance level of drought response, with decreasing drought sensitivity towards higher elevations. Growth conditions were found to be optimal at ~1,300 m asl, with precipitation/drought limiting tree growth below and temperature above. Common years of extreme drought and low growth for the colline sites occurred in 1921, 1944, 1976, 1992, and 1998. Our results demonstrate the potential of lower elevation conifers for reconstructing long-term changes in Alpine hydro-climate. |
| Date Added | 7. duben 2014 13:52:52 |
| Modified | 7. duben 2014 13:52:52 |
| Type | Journal Article |
|---|---|
| Author | David Barriopedro |
| Author | Ricardo García-Herrera |
| Author | Radan Huth |
| URL | http://onlinelibrary.wiley.com/doi/10.1029/2008JD009789/abstract |
| Rights | Copyright 2008 by the American Geophysical Union. |
| Volume | 113 |
| Issue | D14 |
| Pages | D14118 |
| Publication | Journal of Geophysical Research: Atmospheres |
| ISSN | 2156-2202 |
| Date | July 27, 2008 |
| Journal Abbr | J. Geophys. Res. |
| DOI | 10.1029/2008JD009789 |
| Accessed | 7. duben 2014 14:18:29 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | The blocking response to the 11-year solar cycle is investigated for 44 winters (1955–1999) and stratified according to the level of solar activity and the phase of the Quasi-Biennial Oscillation (QBO). Several blocking features are modulated by solar activity, irrespective of the QBO phase, but the responses amplify under the QBO-west phases. Solar activity modulates the preferred locations for blocking occurrence over both Oceans, causing local frequency responses therein. Over the Pacific Ocean high/low solar activity induces an enhanced blocking activity over its eastern/western part. Atlantic blocking occurrence increases for both (high/low) solar phases, with a spatial dependent response confined to western/eastern Atlantic. Although solar effects are negligible in blocking frequency for the entire Atlantic sector, other blocking features exhibit significant responses. Low solar Atlantic blocking episodes last longer, are located further east and become more intense than high solar blocking events. The implications of these solar-related changes are discussed. Our results suggest that the excessively cold conditions recorded in Europe during the Maunder Minimum may have arisen from an eastward shift of long-lasting blockings with near-normal frequencies. |
| Date Added | 7. duben 2014 14:18:29 |
| Modified | 7. duben 2014 14:18:29 |
| Type | Journal Article |
|---|---|
| Author | R. Brázdil |
| Author | M. Trnka |
| Author | P. Dobrovolný |
| Author | K. Chromá |
| Author | P. Hlavinka |
| Author | Z. Žalud |
| URL | http://link.springer.com/article/10.1007/s00704-008-0065-x |
| Volume | 97 |
| Issue | 3-4 |
| Pages | 297-315 |
| Publication | Theoretical and Applied Climatology |
| ISSN | 0177-798X, 1434-4483 |
| Date | 2009/08/01 |
| Journal Abbr | Theor Appl Climatol |
| DOI | 10.1007/s00704-008-0065-x |
| Accessed | 6. duben 2014 22:45:59 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | We analyze droughts in the Czech Republic from 1881–2006 based on the Palmer drought severity index (PDSI) and the Z-index using averaged national temperature and precipitation series for the calculations. The standardized precipitation index (SPI), PDSI and Z-index series show an increasing tendency towards longer and more intensive dry episodes in which, for example, droughts that occurred in the mid-1930s, late 1940s–early 1950s, late 1980s–early 1990s and early 2000s were the most severe. Cycles at periods of 3.4–3.5, 4.2–4.3, 5.0–5.1 and 15.4 years exceeded 95% confidence levels in application of maximum entropy spectral analysis. These are expressed at different intensities throughout the period studied. The occurrence of extremely dry and severely dry months is associated with a higher frequency of anticyclonic situations according to the classification employed by the Czech Hydrometeorological Institute. Principal component analysis documents the importance of the ridge from the Siberian High over Central Europe when extreme and severe droughts in months of the winter half-year are considered in terms of sea-level pressure. In the summer half-year, the ridge of the Azores High over Central Europe is the most important. Drought episodes have a profound effect on national and regional agricultural production, with yields being consistently lower than in normal years, as is documented through the example of spring barley, winter wheat, forage crops on arable land, and hay from meadows. Seasons with pronounced drought during the April–June period (e.g., 1947 and 2000) show the most significant yield decreases. Forests appear to be very vulnerable to long-term drought episodes, as it was the case during the dry years of 1992–1994. This study clearly confirms the statistically significant tendency to more intensive dry episodes in the region, driven by temperature increase and precipitation decrease, which has already been suggested in other studies. |
| Date Added | 6. duben 2014 22:45:59 |
| Modified | 6. duben 2014 22:45:59 |
| Type | Journal Article |
|---|---|
| Author | Rudolf Brázdil |
| Author | Zbigniew W. Kunziewicz |
| Author | Gerardo Benito |
| URL | http://link.springer.com/article/10.1007/s10584-005-5924-1 |
| Volume | 51 |
| Issue | 5 |
| Pages | 739-764 |
| Publication | Hydrological Sciences Journal |
| ISSN | 0262-6667 |
| Date | 2006 |
| DOI | 10.1623/hysj.51.5.739 |
| Accessed | 6. duben 2014 23:33:13 |
| Library Catalog | Taylor and Francis+NEJM |
| Abstract | Abstract Historical hydrology can be defined as a research field occupying the interface between hydrology and history, with the objectives: to reconstruct temporal and spatial patterns of river flow and, in particular, extreme events (floods, ice phenomena, hydrological droughts) mainly for the period prior to the creation of national hydrological networks; and to investigate the vulnerability of past societies and economies to extreme hydrological events. It is a significant tool for the study of flood risk. Basic sources of documentary data on floods and methods of data collection and analysis are discussed. Research progress achieved in Europe in reconstructing past runoff conditions, hydrological and hydraulic analyses of historical floods, their meteorological causes, impacts and relation to climate change, as well as use of combined series of palaeofloods, instrumental and historical floods for reconstructing long-term flood records, is reviewed. Finally, the future research needs of historical hydrology are discussed. |
| Date Added | 6. duben 2014 23:33:13 |
| Modified | 7. duben 2014 0:10:54 |
| Type | Book Section |
|---|---|
| Author | Rudolf Brázdil |
| Author | Zbigniew W. Kundzewicz |
| Author | Gerardo Benito |
| Author | Gaston Demarée |
| Author | Neil Macdonald |
| Author | Lars A. Roald |
| Series | Special Publication |
| Place | Walligford (UK) |
| Publisher | IAHS |
| Pages | 121-166 |
| ISBN | 978-1-907161-28-5 |
| Date | 2012 |
| Series Number | 10 |
| Language | en |
| Abstract | The paper focuses on floods in Europe derived from documentary evidence during the past millennium. The beginnings of early-instrumental and systematic-instrumental hydrological observations in Europe are discussed. Basic sources of documentary evidence related to floods and the problems that may be encountered in the use of historical source materials are described. An overview of documentary-based flood research in the form of long-term frequency and severity series, as well as a summary of the most disastrous floods in the Mediterranean, Western, Central and Northern Europe, is presented. The role and value of floods described in the documentary record to better understanding current flood risks in Europe are discussed. |
| Book Title | Changes in Flood Risk in Europe |
| Date Added | 6. duben 2014 23:40:56 |
| Modified | 6. duben 2014 23:48:35 |
| Type | Journal Article |
|---|---|
| Author | Rudolf Brázdil |
| Author | Christian Pfister |
| Author | Heinz Wanner |
| Author | Hans Von Storch |
| Author | Jürg Luterbacher |
| URL | http://link.springer.com/article/10.1007/s10584-005-5924-1 |
| Volume | 70 |
| Issue | 3 |
| Pages | 363-430 |
| Publication | Climatic Change |
| ISSN | 0165-0009, 1573-1480 |
| Date | 2005/06/01 |
| Journal Abbr | Climatic Change |
| DOI | 10.1007/s10584-005-5924-1 |
| Accessed | 7. duben 2014 22:02:26 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | This paper discusses the state of European research in historical climatology. This field of science and an overview of its development are described in detail. Special attention is given to the documentary evidence used for data sources, including its drawbacks and advantages. Further, methods and significant results of historical-climatological research, mainly achieved since 1990, are presented. The main focus concentrates on data, methods, definitions of the “Medieval Warm Period” and the “Little Ice Age”, synoptic interpretation of past climates, climatic anomalies and natural disasters, and the vulnerability of economies and societies to climate as well as images and social representations of past weather and climate. The potential of historical climatology for climate modelling research is discussed briefly. Research perspectives in historical climatology are formulated with reference to data, methods, interdisciplinarity and impacts. |
| Date Added | 7. duben 2014 22:02:26 |
| Modified | 7. duben 2014 22:03:46 |
| Type | Journal Article |
|---|---|
| Author | Ulf Büntgen |
| Author | Christoph C. Raible |
| Author | David Frank |
| Author | Samuli Helama |
| Author | Laura Cunningham |
| Author | Dominik Hofer |
| Author | Daniel Nievergelt |
| Author | Anne Verstege |
| Author | Mauri Timonen |
| Author | Nils Chr. Stenseth |
| Author | Jan Esper |
| URL | http://dx.doi.org/10.1371/journal.pone.0025133 |
| Volume | 6 |
| Issue | 9 |
| Pages | e25133 |
| Publication | PLoS ONE |
| Date | September 22, 2011 |
| Journal Abbr | PLoS ONE |
| DOI | 10.1371/journal.pone.0025133 |
| Accessed | 6. duben 2014 22:38:59 |
| Library Catalog | PLoS Journals |
| Abstract | Tree rings dominate millennium-long temperature reconstructions and many records originate from Scandinavia, an area for which the relative roles of external forcing and internal variation on climatic changes are, however, not yet fully understood. Here we compile 1,179 series of maximum latewood density measurements from 25 conifer sites in northern Scandinavia, establish a suite of 36 subset chronologies, and analyse their climate signal. A new reconstruction for the 1483–2006 period correlates at 0.80 with June–August temperatures back to 1860. Summer cooling during the early 17th century and peak warming in the 1930s translate into a decadal amplitude of 2.9°C, which agrees with existing Scandinavian tree-ring proxies. Climate model simulations reveal similar amounts of mid to low frequency variability, suggesting that internal ocean-atmosphere feedbacks likely influenced Scandinavian temperatures more than external forcing. Projected 21st century warming under the SRES A2 scenario would, however, exceed the reconstructed temperature envelope of the past 1,500 years. |
| Date Added | 6. duben 2014 22:38:59 |
| Modified | 6. duben 2014 22:38:59 |
| Type | Journal Article |
|---|---|
| Author | Ulf Büntgen |
| Author | Willy Tegel |
| Author | Kurt Nicolussi |
| Author | Michael McCormick |
| Author | David Frank |
| Author | Valerie Trouet |
| Author | Jed O. Kaplan |
| Author | Franz Herzig |
| Author | Karl-Uwe Heussner |
| Author | Heinz Wanner |
| Author | Jürg Luterbacher |
| Author | Jan Esper |
| URL | http://www.sciencemag.org/content/331/6017/578 |
| Volume | 331 |
| Issue | 6017 |
| Pages | 578-582 |
| Publication | Science |
| ISSN | 0036-8075, 1095-9203 |
| Date | 02/04/2011 |
| Extra | PMID: 21233349 |
| Journal Abbr | Science |
| DOI | 10.1126/science.1197175 |
| Accessed | 6. duben 2014 22:42:47 |
| Library Catalog | www.sciencemag.org |
| Language | en |
| Abstract | Climate variations influenced the agricultural productivity, health risk, and conflict level of preindustrial societies. Discrimination between environmental and anthropogenic impacts on past civilizations, however, remains difficult because of the paucity of high-resolution paleoclimatic evidence. We present tree ring–based reconstructions of central European summer precipitation and temperature variability over the past 2500 years. Recent warming is unprecedented, but modern hydroclimatic variations may have at times been exceeded in magnitude and duration. Wet and warm summers occurred during periods of Roman and medieval prosperity. Increased climate variability from ~250 to 600 C.E. coincided with the demise of the western Roman Empire and the turmoil of the Migration Period. Such historical data may provide a basis for counteracting the recent political and fiscal reluctance to mitigate projected climate change. |
| Date Added | 6. duben 2014 22:42:47 |
| Modified | 6. duben 2014 22:42:47 |
| Type | Journal Article |
|---|---|
| Author | Ulf Büntgen |
| Author | David C. Frank |
| Author | Daniel Nievergelt |
| Author | Jan Esper |
| URL | http://journals.ametsoc.org/doi/abs/10.1175/JCLI3917.1 |
| Volume | 19 |
| Issue | 21 |
| Pages | 5606-5623 |
| Publication | Journal of Climate |
| ISSN | 0894-8755, 1520-0442 |
| Date | 11/2006 |
| DOI | 10.1175/JCLI3917.1 |
| Accessed | 7. duben 2014 21:40:48 |
| Library Catalog | CrossRef |
| Language | en |
| Short Title | Summer Temperature Variations in the European Alps |
| Date Added | 7. duben 2014 21:40:48 |
| Modified | 7. duben 2014 21:42:48 |
| Type | Journal Article |
|---|---|
| Author | Ulf Büntgen |
| Author | Jan Esper |
| Author | David C. Frank |
| Author | Kurt Nicolussi |
| Author | Martin Schmidhalter |
| URL | http://link.springer.com/article/10.1007/s00382-005-0028-1 |
| Volume | 25 |
| Issue | 2-3 |
| Pages | 141-153 |
| Publication | Climate Dynamics |
| ISSN | 0930-7575, 1432-0894 |
| Date | 2005/08/01 |
| Journal Abbr | Clim Dyn |
| DOI | 10.1007/s00382-005-0028-1 |
| Accessed | 7. duben 2014 21:44:33 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | A June–August Alpine temperature proxy series is developed back to AD 951 using 1,527 ring-width measurements from living trees and relict wood. The reconstruction is composed of larch data from four Alpine valleys in Switzerland and pine data from the western Austrian Alps. These regions are situated in high elevation Alpine environments where a spatially homogenous summer temperature signal exists. In an attempt to capture the full frequency range of summer temperatures over the past millennium, from inter-annual to multi-centennial scales, the regional curve standardization technique is applied to the ring width measurements. Correlations of 0.65 and 0.86 after decadal smoothing, with high elevation meteorological stations since 1864 indicate an optimal response of the RCS chronology to June–August mean temperatures. The proxy record reveals warm conditions from before AD 1000 into the thirteenth century, followed by a prolonged cool period, reaching minimum values in the 1820s, and a warming trend into the twentieth century. This latter trend and the higher frequency variations compare well with the actual high elevation temperature record. The new central Alpine proxy suggests that summer temperatures during the last decade are unprecedented over the past millennium. It also reveals significant similarities at inter-decadal to multi-centennial frequencies with large-scale temperature reconstructions, however, deviating during certain periods from H.H. Lamb‘s European/North Atlantic temperature history. |
| Date Added | 7. duben 2014 21:44:33 |
| Modified | 7. duben 2014 21:44:33 |
| Type | Journal Article |
|---|---|
| Author | Ulf Büntgen |
| Author | David Frank |
| Author | Rob Wilson |
| Author | Marco Carrer |
| Author | Carlo Urbinati |
| Author | Jan Esper |
| URL | http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2008.01640.x/abstract |
| Rights | © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd |
| Volume | 14 |
| Issue | 10 |
| Pages | 2443-2453 |
| Publication | Global Change Biology |
| ISSN | 1365-2486 |
| Date | October 1, 2008 |
| DOI | 10.1111/j.1365-2486.2008.01640.x |
| Accessed | 7. duben 2014 21:48:09 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | Evidence for reduced sensitivity of tree growth to temperature has been reported from multiple forests along the high northern latitudes. This alleged circumpolar phenomenon described the apparent inability of temperature-sensitive tree-ring width and density chronologies to parallel increasing instrumental temperature measurements since the mid-20th century. In addition to such low-frequency trend offset, the inability of formerly temperature-sensitive tree growth to reflect high-frequency temperature signals in a warming world is indicated at some boreal sites, mainly in Alaska, the Yukon and Siberia. Here, we refer to both of these findings as the ‘divergence problem’ (DP), with their causes and scale being debated. If DP is widespread and the result of climatic forcing, the overall reliability of tree-ring-based temperature reconstructions should be questioned. Testing for DP benefits from well-replicated tree-ring and instrumental data spanning from the 19th to the 21st century. Here, we present a network of 124 larch and spruce sites across the European Alpine arc. Tree-ring width chronologies from 40 larch and 24 spruce sites were selected based on their correlation with early (1864–1933) instrumental temperatures to assess their ability of tracking recent (1934–2003) temperature variations. After the tree-ring series of both species were detrended in a manner that allows low-frequency variations to be preserved and scaled against summer temperatures, no unusual late 20th century DP is found. Independent tree-ring width and density evidence for unprecedented late 20th century temperatures with respect to the past millennium further reinforces our results. |
| Date Added | 7. duben 2014 21:48:09 |
| Modified | 7. duben 2014 21:48:09 |
| Type | Journal Article |
|---|---|
| Author | C. Corona |
| Author | J. Guiot |
| Author | J. L. Edouard |
| Author | F. Chalié |
| Author | U. Büntgen |
| Author | P. Nola |
| Author | C. Urbinati |
| URL | http://www.clim-past.net/6/379/2010/ |
| Volume | 6 |
| Issue | 3 |
| Pages | 379-400 |
| Publication | Clim. Past |
| ISSN | 1814-9332 |
| Date | June 25, 2010 |
| Journal Abbr | Clim. Past |
| DOI | 10.5194/cp-6-379-2010 |
| Accessed | 6. duben 2014 23:54:31 |
| Library Catalog | Copernicus Online Journals |
| Abstract | This paper presents a reconstruction of the summer temperatures over the Greater Alpine Region (44.05°–47.41° N, 6.43°–13° E) during the last millennium based on a network of 38 multi-centennial larch and stone pine chronologies. Tree ring series are standardized using an Adaptative Regional Growth Curve, which attempts to remove the age effect from the low frequency variations in the series. The proxies are calibrated using the June to August mean temperatures from the HISTALP high-elevation temperature time series spanning the 1818–2003. The method combines an analogue technique, which is able to extend the too short tree-ring series, an artificial neural network technique for an optimal non-linear calibration including a bootstrap technique for calculating error assessment on the reconstruction. About 50% of the temperature variance is reconstructed. Low-elevation instrumental data back to 1760 compared to their instrumental target data reveal divergence between (warmer) early instrumental measurements and (colder) proxy estimates. The proxy record indicates cool conditions, from the mid-11th century to the mid-12th century, related to the Oort solar minimum followed by a short Medieval Warm Period (1200–1420). The Little Ice Age (1420–1830) appears particularly cold between 1420 and 1820 with summers that are 0.8 °C cooler than the 1901–2000 period. The new record suggests that the persistency of the late 20th century warming trend is unprecedented. It also reveals significant similarities with other alpine reconstructions. |
| Date Added | 6. duben 2014 23:54:31 |
| Modified | 6. duben 2014 23:54:31 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | Ulf Büntgen |
| Author | Jürg Luterbacher |
| Author | Paul J. Krusic |
| URL | http://www.sciencedirect.com/science/article/pii/S1125786513000258 |
| Volume | 31 |
| Issue | 3 |
| Pages | 216-222 |
| Publication | Dendrochronologia |
| ISSN | 1125-7865 |
| Date | 2013 |
| Journal Abbr | Dendrochronologia |
| DOI | 10.1016/j.dendro.2012.11.002 |
| Accessed | 7. duben 2014 0:01:44 |
| Library Catalog | ScienceDirect |
| Abstract | The precise, annual dating control, inherent to dendrochronology, has recently been questioned through a combined analysis of tree-growth and coupled climate models (Mann et al. (2012; hereafter MAN12)) suggesting single tree-rings in temperature limited environments are missing following large volcanic events. We test this hypothesis of missing, post-volcanic rings by using a compilation of maximum latewood density (MXD) records that are typically used for reconstructing temperature and the detection of volcanic events, together with a unique set of long instrumental station data from Europe reaching back into the early 18th century. We investigate the temporal coherence between tree-ring MXD and observed summer temperatures before and after the most significant, precisely dated, volcanic event of the past 1000 years, the 1815 Tambora eruption widely known as the cause for the 1816 “year without a summer”. Comparison of existing and newly developed MXD chronologies from cold environments in Northern Scandinavia (<img height="13" border="0" style="vertical-align:bottom" width="87" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S1125786513000258-si2.gif">r¯North=0.70, N = 3) and the European Alps, including the Pyrenees, (<img height="14" border="0" style="vertical-align:bottom" width="95" alt="View the MathML source" title="View the MathML source" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S1125786513000258-si3.gif">r¯Central=0.46, N = 4) reveals significant interseries correlations over the 1722–1976 common period, suggesting coherence among these independently developed timeseries. Comparisons of these data with observed JJA temperatures – from 1722 to 1976, a 94-year pre-Tambora (1722–1815), and a 94-year post-Tambora (1817–1910) period – reveals significant and temporally stable correlations ranging from 0.32 to 0.68. However, if we assume the 1816 ring is missing in the MXD chronologies (i.e., shift the pre-Tambora data by one year), all proxy/instrumental correlations fall apart approaching zero. Results from an additional experiment, where the long instrumental record is replaced by an annually resolved, 500-year, summer temperature reconstruction derived from documentary evidence, corroborates the findings from the first experiment: significant positive correlations with the unmolested chronologies and zero correlation with the perturbed chronologies back to 1500 AD. These elementary analyses indicate that either the tree-ring chronologies are correctly dated, i.e., no is ring missing in the year without a summer, or that both the long instrumental and documentary records contain dating uncertainties. As the latter is unlikely, we conclude the MAN12 hypothesis on post-volcanic missing rings can be rejected based on simple comparisons of tree-ring, instrumental and documentary data over the past 300–500 years from Central and Northern Europe. |
| Date Added | 7. duben 2014 0:01:44 |
| Modified | 7. duben 2014 0:01:44 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | David C. Frank |
| Author | Mauri Timonen |
| Author | Eduardo Zorita |
| Author | Rob J. S. Wilson |
| Author | Jürg Luterbacher |
| Author | Steffen Holzkämper |
| Author | Nils Fischer |
| Author | Sebastian Wagner |
| Author | Daniel Nievergelt |
| Author | Anne Verstege |
| Author | Ulf Büntgen |
| URL | http://www.nature.com/nclimate/journal/v2/n12/abs/nclimate1589.html |
| Rights | © 2012 Nature Publishing Group |
| Volume | 2 |
| Issue | 12 |
| Pages | 862-866 |
| Publication | Nature Climate Change |
| ISSN | 1758-678X |
| Date | December 2012 |
| Journal Abbr | Nature Clim. Change |
| DOI | 10.1038/nclimate1589 |
| Accessed | 7. duben 2014 14:00:24 |
| Library Catalog | www.nature.com |
| Language | en |
| Abstract | Solar insolation changes, resulting from long-term oscillations of orbital configurations, are an important driver of Holocene climate. The forcing is substantial over the past 2,000 years, up to four times as large as the 1.6 W m−2 net anthropogenic forcing since 1750 (ref. 4), but the trend varies considerably over time, space and with season. Using numerous high-latitude proxy records, slow orbital changes have recently been shown to gradually force boreal summer temperature cooling over the common era. Here, we present new evidence based on maximum latewood density data from northern Scandinavia, indicating that this cooling trend was stronger (−0.31 °C per 1,000 years, ±0.03 °C) than previously reported, and demonstrate that this signature is missing in published tree-ring proxy records. The long-term trend now revealed in maximum latewood density data is in line with coupled general circulation models indicating albedo-driven feedback mechanisms and substantial summer cooling over the past two millennia in northern boreal and Arctic latitudes. These findings, together with the missing orbital signature in published dendrochronological records, suggest that large-scale near-surface air-temperature reconstructions relying on tree-ring data may underestimate pre-instrumental temperatures including warmth during Medieval and Roman times. |
| Date Added | 7. duben 2014 14:00:24 |
| Modified | 7. duben 2014 14:00:24 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | David Frank |
| Author | Ulf Büntgen |
| Author | Anne Verstege |
| Author | Rashit M. Hantemirov |
| Author | Alexander V. Kirdyanov |
| URL | http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2009.01913.x/abstract |
| Rights | © 2009 Blackwell Publishing Ltd |
| Volume | 16 |
| Issue | 1 |
| Pages | 386-398 |
| Publication | Global Change Biology |
| ISSN | 1365-2486 |
| Date | January 1, 2010 |
| DOI | 10.1111/j.1365-2486.2009.01913.x |
| Accessed | 7. duben 2014 14:01:30 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | Estimates of past climate and future forest biomass dynamics are constrained by uncertainties in the relationships between growth and climatic variability and uncertainties in the instrumental data themselves. Of particular interest in this regard is the boreal-forest zone, where radial growth has historically been closely connected with temperature variability, but various lines of evidence have indicated a decoupling since about the 1960s. We here address this growth-vs.-temperature divergence by analyzing tree-ring width and density data from across Siberia, and comparing 20th century proxy trends with those derived from instrumental stations. We test the influence of approaches considered in the recent literature on the divergence phenomenon (DP), including effects of tree-ring standardization and calibration period, and explore instrumental uncertainties by employing both adjusted and nonadjusted temperature data to assess growth-climate agreement. Results indicate that common methodological and data usage decisions alter 20th century growth and temperature trends in a way that can easily explain the post-1960 DP. We show that (i) Siberian station temperature adjustments were up to 1.3 °C for decadal means before 1940, (ii) tree-ring detrending effects in the order of 0.6–0.8 °C, and (iii) calibration uncertainties up to about 0.4 °C over the past 110 years. Despite these large uncertainties, instrumental and tree growth estimates for the entire 20th century warming interval match each other, to a degree previously not recognized, when care is taken to preserve long-term trends in the tree-ring data. We further show that careful examination of early temperature data and calibration of proxy timeseries over the full period of overlap with instrumental data are both necessary to properly estimate 20th century long-term changes and to avoid erroneous detection of post-1960 divergence. |
| Date Added | 7. duben 2014 14:01:30 |
| Modified | 7. duben 2014 14:01:30 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | Ulf Büntgen |
| Author | Mauri Timonen |
| Author | David C. Frank |
| URL | http://www.sciencedirect.com/science/article/pii/S0921818112000070 |
| Volume | 88–89 |
| Pages | 1-9 |
| Publication | Global and Planetary Change |
| ISSN | 0921-8181 |
| Date | May 2012 |
| Journal Abbr | Global and Planetary Change |
| DOI | 10.1016/j.gloplacha.2012.01.006 |
| Accessed | 7. duben 2014 14:02:56 |
| Library Catalog | ScienceDirect |
| Abstract | Palaeoclimatic evidence revealed synchronous temperature variations among Northern Hemisphere regions over the past millennium. The range of these variations (in degrees Celsius) is, however, largely unknown. We here present a 2000-year summer temperature reconstruction from northern Scandinavia and compare this timeseries with existing proxy records to assess the range of reconstructed temperatures at a regional scale. The new reconstruction is based on 578 maximum latewood density profiles from living and sub-fossil Pinus sylvestris samples from northern Sweden and Finland. The record provides evidence for substantial warmth during Roman and Medieval times, larger in extent and longer in duration than 20th century warmth. The first century AD was the warmest 100-year period (+ 0.60 °C on average relative to the 1951–1980 mean) of the Common Era, more than 1 °C warmer than the coldest 14th century AD (− 0.51 °C). The warmest and coldest reconstructed 30-year periods (AD 21–50 = + 1.05 °C, and AD 1451–80 = − 1.19 °C) differ by more than 2 °C, and the range between the five warmest and coldest reconstructed summers in the context of the past 2000 years is estimated to exceed 5 °C. Comparison of the new timeseries with five existing tree-ring based reconstructions from northern Scandinavia revealed synchronized climate fluctuations but substantially different absolute temperatures. Level offset among the various reconstructions in extremely cold and warm years (up to 3 °C) and cold and warm 30-year periods (up to 1.5 °C) are in the order of the total temperature variance of each individual reconstruction over the past 1500 to 2000 years. These findings demonstrate our poor understanding of the absolute temperature variance in a region where high-resolution proxy coverage is denser than in any other area of the world. |
| Date Added | 7. duben 2014 14:02:56 |
| Modified | 7. duben 2014 14:02:56 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | David C. Frank |
| Author | Robert J. S. Wilson |
| Author | Ulf Büntgen |
| Author | Kerstin Treydte |
| URL | http://link.springer.com/article/10.1007/s00468-006-0104-0 |
| Volume | 21 |
| Issue | 2 |
| Pages | 141-150 |
| Publication | Trees |
| ISSN | 0931-1890, 1432-2285 |
| Date | 2007/03/01 |
| Journal Abbr | Trees |
| DOI | 10.1007/s00468-006-0104-0 |
| Accessed | 7. duben 2014 21:49:49 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | We present an analysis of 28 juniper tree-ring sites sampled over the last decades by several research teams in the Tien Shan and Karakorum mountains of western central Asia. Ring-width chronologies were developed on a site-by-site basis, using a detrending technique designed to retain low-frequency climate variations. Site chronologies were grouped according to their distance from the upper timberline in the Tien Shan (∼3,400 m a.s.l.) and Karakorum (∼4,000 m), and low- and high-elevation composite chronologies combining data from both mountain systems developed. Comparison of these elevational subsets revealed significant coherence (r = 0.72) over the 1438–1995 common period, which is inconsistent with the concept of differing environmental signals captured in tree-ring data along elevational gradients. It is hypothesized that the uniform growth behavior in central Asian juniper trees has been forced by solar radiation variations controlled via cloud cover changes, but verification of this assumption requires further fieldwork. The high-elevation composite chronology was further compared with existing temperature reconstructions from the Karakorum and Tien Shan, and long-term trend differences discussed. We concluded that the extent of warmth during medieval times cannot be precisely estimated based on ring-width data currently available. |
| Date Added | 7. duben 2014 21:49:49 |
| Modified | 7. duben 2014 21:49:49 |
| Type | Journal Article |
|---|---|
| Author | Jan Esper |
| Author | David Frank |
| Author | Ulf Büntgen |
| Author | Anne Verstege |
| Author | Jürg Luterbacher |
| Author | Elena Xoplaki |
| URL | http://onlinelibrary.wiley.com/doi/10.1029/2007GL030844/abstract |
| Rights | Copyright 2007 by the American Geophysical Union. |
| Volume | 34 |
| Issue | 17 |
| Pages | L17702 |
| Publication | Geophysical Research Letters |
| ISSN | 1944-8007 |
| Date | September 1, 2007 |
| Journal Abbr | Geophys. Res. Lett. |
| DOI | 10.1029/2007GL030844 |
| Accessed | 7. duben 2014 21:50:52 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | Cedrus atlantica ring width data are used to reconstruct long-term changes in the Palmer Drought Severity Index (PDSI) over the past 953 years in Morocco, NW Africa. The reconstruction captures the dry conditions since the 1980s well and places this extreme period within a millennium-long context. PDSI values were above average for most of the 1450–1980 period, which let recent drought appear exceptional. However, our results also indicate that this pluvial episode of the past millennium was preceded by generally drier conditions back to 1049. Comparison of PDSI estimates with large-scale pressure field reconstructions revealed steady synoptic patterns for drought conditions over the past 350 years. The long-term changes from initially dry to pluvial to recent dry conditions are similar to PDSI trends reported from N America, and we suggest that they are related to long-term temperature changes, potentially teleconnected with ENSO variability and forced by solar irradiance changes. |
| Date Added | 7. duben 2014 21:50:52 |
| Modified | 7. duben 2014 21:50:52 |
| Type | Journal Article |
|---|---|
| Author | Adrien C. Finzi |
| Author | Richard J. Norby |
| Author | Carlo Calfapietra |
| Author | Anne Gallet-Budynek |
| Author | Birgit Gielen |
| Author | William E. Holmes |
| Author | Marcel R. Hoosbeek |
| Author | Colleen M. Iversen |
| Author | Robert B. Jackson |
| Author | Mark E. Kubiske |
| Author | Joanne Ledford |
| Author | Marion Liberloo |
| Author | Ram Oren |
| Author | Andrea Polle |
| Author | Seth Pritchard |
| Author | Donald R. Zak |
| Author | William H. Schlesinger |
| Author | Reinhart Ceulemans |
| URL | http://www.pnas.org/content/104/35/14014 |
| Volume | 104 |
| Issue | 35 |
| Pages | 14014-14019 |
| Publication | Proceedings of the National Academy of Sciences |
| ISSN | 0027-8424, 1091-6490 |
| Date | 08/28/2007 |
| Extra | PMID: 17709743 |
| Journal Abbr | PNAS |
| DOI | 10.1073/pnas.0706518104 |
| Accessed | 7. duben 2014 21:34:54 |
| Library Catalog | www.pnas.org |
| Language | en |
| Abstract | Forest ecosystems are important sinks for rising concentrations of atmospheric CO2. In previous research, we showed that net primary production (NPP) increased by 23 ± 2% when four experimental forests were grown under atmospheric concentrations of CO2 predicted for the latter half of this century. Because nitrogen (N) availability commonly limits forest productivity, some combination of increased N uptake from the soil and more efficient use of the N already assimilated by trees is necessary to sustain the high rates of forest NPP under free-air CO2 enrichment (FACE). In this study, experimental evidence demonstrates that the uptake of N increased under elevated CO2 at the Rhinelander, Duke, and Oak Ridge National Laboratory FACE sites, yet fertilization studies at the Duke and Oak Ridge National Laboratory FACE sites showed that tree growth and forest NPP were strongly limited by N availability. By contrast, nitrogen-use efficiency increased under elevated CO2 at the POP-EUROFACE site, where fertilization studies showed that N was not limiting to tree growth. Some combination of increasing fine root production, increased rates of soil organic matter decomposition, and increased allocation of carbon (C) to mycorrhizal fungi is likely to account for greater N uptake under elevated CO2. Regardless of the specific mechanism, this analysis shows that the larger quantities of C entering the below-ground system under elevated CO2 result in greater N uptake, even in N-limited ecosystems. Biogeochemical models must be reformulated to allow C transfers below ground that result in additional N uptake under elevated CO2. |
| Date Added | 7. duben 2014 21:34:54 |
| Modified | 7. duben 2014 21:34:54 |
| Type | Journal Article |
|---|---|
| Author | David C. Frank |
| Author | Jan Esper |
| Author | Christoph C. Raible |
| Author | Ulf Büntgen |
| Author | Valerie Trouet |
| Author | Benjamin Stocker |
| Author | Fortunat Joos |
| URL | http://www.nature.com/nature/journal/v463/n7280/abs/nature08769.html |
| Rights | © 2010 Nature Publishing Group |
| Volume | 463 |
| Issue | 7280 |
| Pages | 527-530 |
| Publication | Nature |
| ISSN | 0028-0836 |
| Date | January 28, 2010 |
| Journal Abbr | Nature |
| DOI | 10.1038/nature08769 |
| Accessed | 7. duben 2014 14:06:00 |
| Library Catalog | www.nature.com |
| Language | en |
| Abstract | The processes controlling the carbon flux and carbon storage of the atmosphere, ocean and terrestrial biosphere are temperature sensitive and are likely to provide a positive feedback leading to amplified anthropogenic warming. Owing to this feedback, at timescales ranging from interannual to the 20–100-kyr cycles of Earth's orbital variations, warming of the climate system causes a net release of CO2 into the atmosphere; this in turn amplifies warming. But the magnitude of the climate sensitivity of the global carbon cycle (termed γ), and thus of its positive feedback strength, is under debate, giving rise to large uncertainties in global warming projections. Here we quantify the median γ as 7.7 p.p.m.v. CO2 per °C warming, with a likely range of 1.7–21.4 p.p.m.v. CO2 per °C. Sensitivity experiments exclude significant influence of pre-industrial land-use change on these estimates. Our results, based on the coupling of a probabilistic approach with an ensemble of proxy-based temperature reconstructions and pre-industrial CO2 data from three ice cores, provide robust constraints for γ on the policy-relevant multi-decadal to centennial timescales. By using an ensemble of >200,000 members, quantification of γ is not only improved, but also likelihoods can be assigned, thereby providing a benchmark for future model simulations. Although uncertainties do not at present allow exclusion of γ calculated from any of ten coupled carbon–climate models, we find that γ is about twice as likely to fall in the lowermost than in the uppermost quartile of their range. Our results are incompatibly lower (P < 0.05) than recent pre-industrial empirical estimates of ~40 p.p.m.v. CO2 per °C (refs 6, 7), and correspondingly suggest ~80% less potential amplification of ongoing global warming. |
| Date Added | 7. duben 2014 14:06:00 |
| Modified | 7. duben 2014 14:06:00 |
| Type | Book Section |
|---|---|
| Author | C. M. Goodess |
| Author | D. Jacob |
| Author | M. Déqué |
| Author | J. M. Guttiérrez |
| Author | R. Huth |
| Author | E. Kendon |
| Author | G. C. Leckebusch |
| Author | P. Lorenz |
| Author | V. Pavan |
| URL | http://ensembles-eu.metoffice.com/docs/Ensembles_final_report_Nov09.pdf |
| Place | Exeter |
| Publisher | Met Office Hadley Centre |
| Pages | 59-78 |
| Date | 2009 |
| Book Title | ENSEMBLES: Climate change and its impacts at seasonal, decadal and centennial timescales |
| Date Added | 7. duben 2014 14:34:25 |
| Modified | 7. duben 2014 14:42:29 |
| Type | Journal Article |
|---|---|
| Author | Martin Hirschi |
| Author | Sonia I. Seneviratne |
| Author | Vesselin Alexandrov |
| Author | Fredrik Boberg |
| Author | Constanta Boroneant |
| Author | Ole B. Christensen |
| Author | Herbert Formayer |
| Author | Boris Orlowsky |
| Author | Petr Stepanek |
| URL | http://www.nature.com/ngeo/journal/v4/n1/abs/ngeo1032.html |
| Rights | © 2010 Nature Publishing Group |
| Volume | 4 |
| Issue | 1 |
| Pages | 17-21 |
| Publication | Nature Geoscience |
| ISSN | 1752-0894 |
| Date | January 2011 |
| Journal Abbr | Nature Geosci |
| DOI | 10.1038/ngeo1032 |
| Accessed | 7. duben 2014 16:24:58 |
| Library Catalog | www.nature.com |
| Language | en |
| Abstract | Climate change is expected to affect not only the means of climatic variables, but also their variabilities and extremes such as heat waves. In particular, modelling studies have postulated a possible impact of soil-moisture deficit and drought on hot extremes. Such effects could be responsible for impending changes in the occurrence of heat waves in Europe. Here we analyse observational indices based on measurements at 275 meteorological stations in central and southeastern Europe, and on publicly available gridded observations. We find a relationship between soil-moisture deficit, as expressed by the standardized precipitation index, and summer hot extremes in southeastern Europe. This relationship is stronger for the high end of the distribution of temperature extremes. We compare our results with simulations of current climate models and find that the models correctly represent the soil-moisture impacts on temperature extremes in southeastern Europe, but overestimate them in central Europe. Given the memory associated with soil moisture storage, our findings may help with climate-change-adaptation measures, such as early-warning and prediction tools for extreme heat waves. |
| Date Added | 7. duben 2014 16:24:58 |
| Modified | 7. duben 2014 16:24:58 |
| Type | Journal Article |
|---|---|
| Author | M. A. Iqbal |
| Author | J. Eitzinger |
| Author | H. Formayer |
| Author | A. Hassan |
| Author | L. K. Heng |
| URL | http://dx.doi.org/10.1017/S0021859610001243 |
| Volume | 149 |
| Issue | 02 |
| Pages | 129-143 |
| Publication | The Journal of Agricultural Science |
| Date | 2011 |
| DOI | 10.1017/S0021859610001243 |
| Library Catalog | Cambridge Journals Online |
| Date Added | 7. duben 2014 15:21:55 |
| Modified | 7. duben 2014 15:25:39 |
| Type | Journal Article |
|---|---|
| Author | A. Klik |
| Author | J. Eitzinger |
| URL | http://dx.doi.org/10.1017/S0021859610000158 |
| Volume | 148 |
| Issue | 05 |
| Pages | 529-541 |
| Publication | The Journal of Agricultural Science |
| Date | 2010 |
| DOI | 10.1017/S0021859610000158 |
| Library Catalog | Cambridge Journals Online |
| Date Added | 7. duben 2014 14:11:24 |
| Modified | 7. duben 2014 15:30:55 |
| Type | Journal Article |
|---|---|
| Author | E. Kocmánková |
| Author | M. Trnka |
| Author | J. Eitzinger |
| Author | H. Formayer |
| Author | M. Dubrovsk |
| Author | D. Semerdov |
| Author | Z. alud |
| Author | J. Juroch |
| Author | M. Mon |
| URL | http://www.int-res.com/abstracts/cr/v44/n1/p95-105/ |
| Volume | 44 |
| Issue | 1 |
| Pages | 95-105 |
| Publication | Climate Research |
| Date | October 28, 2010 |
| Journal Abbr | Clim Res |
| DOI | 10.3354/cr00905 |
| Accessed | 6. duben 2014 22:52:18 |
| Library Catalog | Inter-Research Science Center |
| Abstract | ABSTRACT: The intensity and area of occurrence of pest species are strongly determined by the overall climate conditions of a locality and the weather pattern within a given season in combination with other factors (e.g. host plant abundance). While inter-seasonal weather variability and consequent fluctuations of individual pest species are well-known phenomena, changes in overall climate conditions and associated range shifts of particular species have likewise become important areas of research, especially during the last decade. The present study demonstrates the methodology and benefits of climate-driven modelling tools using the European corn borer (ECB) Ostrinia nubilalis (Hübner, 1796) and Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say, 1824) as examples. CLIMEX models of the potential geographical distributions of each species were created and validated under present climate conditions. Both models were then used to study the effects of climate change on ECB and CPB by estimating changes in population dynamics and/or infestation pressure during the first half of the 21st century. Simulations were conducted using 3 global circulation models (HadCM3, NCAR-PCM, and ECHAM4) and scaled by low and high values of global temperature change. The results predict an increase in newly established areas and in the number of pest generations per year. The ratio of arable land affected by a particular number of generations is also expected to increase. Under the HadCM3-high 2050 scenario, this ratio increases by about 43 and 48% for the second generations of CPB and ECB, respectively. Another significant result is shown for higher altitudes currently unoccupied by pests. We recorded rapid generation increase (from 0 to 2), which supports the hypothesis that these areas are more affected by increased temperatures. |
| Date Added | 6. duben 2014 22:52:18 |
| Modified | 7. duben 2014 13:54:24 |
| Type | Journal Article |
|---|---|
| Author | Jan Kyselý |
| Author | Romana Beranová |
| URL | http://link.springer.com/article/10.1007/s00704-008-0014-8 |
| Volume | 95 |
| Issue | 3-4 |
| Pages | 361-374 |
| Publication | Theoretical and Applied Climatology |
| ISSN | 0177-798X, 1434-4483 |
| Date | 2009/03/01 |
| Journal Abbr | Theor Appl Climatol |
| DOI | 10.1007/s00704-008-0014-8 |
| Accessed | 7. duben 2014 21:52:47 |
| Library Catalog | link.springer.com |
| Language | en |
| Abstract | Observations as well as most climate model simulations are generally in accord with the hypothesis that the hydrologic cycle should intensify and become highly volatile with the greenhouse-gas-induced climate change, although uncertainties of these projections as well as the spatial and seasonal variability of the changes are much larger than for temperature extremes. In this study, we examine scenarios of changes in extreme precipitation events in 24 future climate runs of ten regional climate models, focusing on a specific area of the Czech Republic (central Europe) where complex orography and an interaction of other factors governing the occurrence of heavy precipitation events result in patterns that cannot be captured by global models. The peaks-over-threshold analysis with increasing threshold censoring is applied to estimate multi-year return levels of daily rainfall amounts. Uncertainties in scenarios of changes for the late 21st century related to the inter-model and within-ensemble variability and the use of the SRES-A2 and SRES-B2 greenhouse gas emission scenarios are evaluated. The results show that heavy precipitation events are likely to increase in severity in winter and (with less agreement among models) also in summer. The inter-model and intra-model variability and related uncertainties in the pattern and magnitude of the change is large, but the scenarios tend to agree with precipitation trends recently observed in the area, which may strengthen their credibility. In most scenario runs, the projected change in extreme precipitation in summer is of the opposite sign than a change in mean seasonal totals, the latter pointing towards generally drier conditions in summer. A combination of enhanced heavy precipitation amounts and reduced water infiltration capabilities of a dry soil may severely increase peak river discharges and flood-related risks in this region. |
| Short Title | Climate-change effects on extreme precipitation in central Europe |
| Date Added | 7. duben 2014 21:52:47 |
| Modified | 7. duben 2014 21:52:47 |
| Type | Journal Article |
|---|---|
| Author | Marion Liberloo |
| Author | Sebastiaan Luyssaert |
| Author | Valentin Bellassen |
| Author | Sylvestre Njakou Djomo |
| Author | Martin Lukac |
| Author | Carlo Calfapietra |
| Author | Ivan A. Janssens |
| Author | Marcel R. Hoosbeek |
| Author | Nicolas Viovy |
| Author | Galina Churkina |
| Author | Giuseppe Scarascia-Mugnozza |
| Author | Reinhart Ceulemans |
| URL | http://dx.doi.org/10.1371/journal.pone.0011648 |
| Volume | 5 |
| Issue | 7 |
| Pages | e11648 |
| Publication | PLoS ONE |
| Date | July 19, 2010 |
| Journal Abbr | PLoS ONE |
| DOI | 10.1371/journal.pone.0011648 |
| Accessed | 6. duben 2014 23:49:46 |
| Library Catalog | PLoS Journals |
| Abstract | Background If biofuels are to be a viable substitute for fossil fuels, it is essential that they retain their potential to mitigate climate change under future atmospheric conditions. Elevated atmospheric CO2 concentration [CO2] stimulates plant biomass production; however, the beneficial effects of increased production may be offset by higher energy costs in crop management. Methodology/Main Findings We maintained full size poplar short rotation coppice (SRC) systems under both current ambient and future elevated [CO2] (550 ppm) and estimated their net energy and greenhouse gas balance. We show that a poplar SRC system is energy efficient and produces more energy than required for coppice management. Even more, elevated [CO2] will increase the net energy production and greenhouse gas balance of a SRC system with 18%. Managing the trees in shorter rotation cycles (i.e., 2 year cycles instead of 3 year cycles) will further enhance the benefits from elevated [CO2] on both the net energy and greenhouse gas balance. Conclusions/Significance Adapting coppice management to the future atmospheric [CO2] is necessary to fully benefit from the climate mitigation potential of bio-energy systems. Further, a future increase in potential biomass production due to elevated [CO2] outweighs the increased production costs resulting in a northward extension of the area where SRC is greenhouse gas neutral. Currently, the main part of the European terrestrial carbon sink is found in forest biomass and attributed to harvesting less than the annual growth in wood. Because SRC is intensively managed, with a higher turnover in wood production than conventional forest, northward expansion of SRC is likely to erode the European terrestrial carbon sink. |
| Date Added | 6. duben 2014 23:49:46 |
| Modified | 6. duben 2014 23:49:46 |
| Type | Journal Article |
|---|---|
| Author | Mariano H. Masiokas |
| Author | Ricardo Villalba |
| Author | Brian H. Luckman |
| Author | Marcelo E. Lascano |
| Author | Silvia Delgado |
| Author | Petr Stepanek |
| URL | http://www.sciencedirect.com/science/article/pii/S0921818107000185 |
| Series | Historical and Holocene glacier – climate variations |
| Volume | 60 |
| Issue | 1–2 |
| Pages | 85-100 |
| Publication | Global and Planetary Change |
| ISSN | 0921-8181 |
| Date | January 2008 |
| Journal Abbr | Global and Planetary Change |
| DOI | 10.1016/j.gloplacha.2006.07.031 |
| Accessed | 7. duben 2014 21:33:05 |
| Library Catalog | ScienceDirect |
| Abstract | This paper documents the occurrence of significant glacier and hydroclimatic changes in northwestern Patagonia during the past century. Drastic, widespread glacier recession is documented by repeat photography of some of the earliest glacier images from southern South America. Linear trends in regionally-averaged annual and seasonal temperature and precipitation records indicate significant warming and decreasing precipitation over the 1912–2002 interval. A climatic index is developed, based on winter precipitation and summer temperature records, that mimics glacier mass balance relationships and shows a strong negative trend which agrees with the drastic glacier recession shown by the photographic comparisons. Short positive periods of this climatic index broadly correspond with known evidence of glacier advances in the region. Regionally-averaged mean annual streamflow records east of the mountains were used in an independent verification check of the climatic series used in this study. This regional runoff record shows a strong negative trend, remarkable similarities with the climatic index, and highly significant positive (negative) correlations with the regional precipitation (temperature) series. This highlights the existence of a strong, regionally coherent hydroclimatic signal across this region and supports the utility of these records as environmental indicators for northwestern Patagonia between ca. 38° and 45°S. Given the significant socio-economic importance of rivers and glaciers in this area, further research is needed to evaluate the full range of natural hydroclimate variability and improve understanding of potential impacts of the future warmer and drier climates projected for this region. |
| Date Added | 7. duben 2014 21:33:05 |
| Modified | 7. duben 2014 21:33:05 |
| Type | Journal Article |
|---|---|
| Author | J. E. Olesen |
| Author | M. Trnka |
| Author | K. C. Kersebaum |
| Author | A. O. Skjelvåg |
| Author | B. Seguin |
| Author | P. Peltonen-Sainio |
| Author | F. Rossi |
| Author | J. Kozyra |
| Author | F. Micale |
| URL | http://www.sciencedirect.com/science/article/pii/S1161030110001061 |
| Volume | 34 |
| Issue | 2 |
| Pages | 96-112 |
| Publication | European Journal of Agronomy |
| ISSN | 1161-0301 |
| Date | February 2011 |
| Journal Abbr | European Journal of Agronomy |
| DOI | 10.1016/j.eja.2010.11.003 |
| Accessed | 6. duben 2014 22:55:03 |
| Library Catalog | ScienceDirect |
| Abstract | The studies on anthropogenic climate change performed in the last decade over Europe show consistent projections of increases in temperature and different patterns of precipitation with widespread increases in northern Europe and decreases over parts of southern and eastern Europe. In many countries and in recent years there is a tendency towards cereal grain yield stagnation and increased yield variability. Some of these trends may have been influenced by the recent climatic changes over Europe. A set of qualitative and quantitative questionnaires on perceived risks and foreseen impacts of climate and climate change on agriculture in Europe was distributed to agro-climatic and agronomy experts in 26 countries. Europe was divided into 13 Environmental Zones (EZ). In total, we had 50 individual responses for specific EZ. The questionnaires provided both country and EZ specific information on the: (1) main vulnerabilities of crops and cropping systems under present climate; (2) estimates of climate change impacts on the production of nine selected crops; (3) possible adaptation options as well as (4) adaptation observed so far. In addition we focused on the overall awareness and presence of warning and decision support systems with relevance for adaptation to climate change. The results show that farmers across Europe are currently adapting to climate change, in particular in terms of changing timing of cultivation and selecting other crop species and cultivars. The responses in the questionnaires show a surprisingly high proportion of negative expectations concerning the impacts of climate change on crops and crop production throughout Europe, even in the cool temperate northern European countries. The expected impacts, both positive and negative, are just as large in northern Europe as in the Mediterranean countries, and this is largely linked with the possibilities for effective adaptation to maintain current yields. The most negative effects were found for the continental climate in the Pannonian zone, which includes Hungary, Serbia, Bulgaria and Romania. This region will suffer from increased incidents of heat waves and droughts without possibilities for effectively shifting crop cultivation to other parts of the years. A wide range of adaptation options exists in most European regions to mitigate many of the negative impacts of climate change on crop production in Europe. However, considering all effects of climate change and possibilties for adaptation, impacts are still mostly negative in wide regions across Europe. |
| Date Added | 6. duben 2014 22:55:03 |
| Modified | 6. duben 2014 22:55:03 |
| Type | Journal Article |
|---|---|
| Author | Taru Palosuo |
| Author | Kurt Christian Kersebaum |
| Author | Carlos Angulo |
| Author | Petr Hlavinka |
| Author | Marco Moriondo |
| Author | Jørgen E. Olesen |
| Author | Ravi H. Patil |
| Author | Françoise Ruget |
| Author | Christian Rumbaur |
| Author | Jozef Takáč |
| Author | Miroslav Trnka |
| Author | Marco Bindi |
| Author | Barış Çaldağ |
| Author | Frank Ewert |
| Author | Roberto Ferrise |
| Author | Wilfried Mirschel |
| Author | Levent Şaylan |
| Author | Bernard Šiška |
| Author | Reimund Rötter |
| URL | http://www.sciencedirect.com/science/article/pii/S1161030111000542 |
| Volume | 35 |
| Issue | 3 |
| Pages | 103-114 |
| Publication | European Journal of Agronomy |
| ISSN | 1161-0301 |
| Date | October 2011 |
| Journal Abbr | European Journal of Agronomy |
| DOI | 10.1016/j.eja.2011.05.001 |
| Accessed | 6. duben 2014 22:59:35 |
| Library Catalog | ScienceDirect |
| Abstract | We compared the performance of eight widely used, easily accessible and well-documented crop growth simulation models (APES, CROPSYST, DAISY, DSSAT, FASSET, HERMES, STICS and WOFOST) for winter wheat (Triticum aestivum L.) during 49 growing seasons at eight sites in northwestern, Central and southeastern Europe. The aim was to examine how different process-based crop models perform at the field scale when provided with a limited set of information for model calibration and simulation, reflecting the typical use of models for large-scale applications, and to present the uncertainties related to this type of model application. Data used in the simulations consisted of daily weather statistics, information on soil properties, information on crop phenology for each cultivar, and basic crop and soil management information. Our results showed that none of the models perfectly reproduced recorded observations at all sites and in all years, and none could unequivocally be labelled robust and accurate in terms of yield prediction across different environments and crop cultivars with only minimum calibration. The best performance regarding yield estimation was for DAISY and DSSAT, for which the RMSE values were lowest (1428 and 1603 kg ha−1) and the index of agreement (0.71 and 0.74) highest. CROPSYST systematically underestimated yields (MBE – 1186 kg ha−1), whereas HERMES, STICS and WOFOST clearly overestimated them (MBE 1174, 1272 and 1213 kg ha−1, respectively). APES, DAISY, HERMES, STICS and WOFOST furnished high total above-ground biomass estimates, whereas CROPSYST, DSSAT and FASSET provided low total above-ground estimates. Consequently, DSSAT and FASSET produced very high harvest index values, followed by HERMES and WOFOST. APES and DAISY, on the other hand, returned low harvest index values. In spite of phenological observations being provided, the calibration results for wheat phenology, i.e. estimated dates of anthesis and maturity, were surprisingly variable, with the largest RMSE for anthesis being generated by APES (20.2 days) and for maturity by HERMES (12.6). The wide range of grain yield estimates provided by the models for all sites and years reflects substantial uncertainties in model estimates achieved with only minimum calibration. Mean predictions from the eight models, on the other hand, were in good agreement with measured data. This applies to both results across all sites and seasons as well as to prediction of observed yield variability at single sites – a very important finding that supports the use of multi-model estimates rather than reliance on single models. |
| Short Title | Simulation of winter wheat yield and its variability in different climates of Europe |
| Date Added | 6. duben 2014 22:59:35 |
| Modified | 6. duben 2014 22:59:35 |
| Type | Journal Article |
|---|---|
| Author | R. P. Rötter |
| Author | T. Palosuo |
| Author | N. K. Pirttioja |
| Author | M. Dubrovsky |
| Author | T. Salo |
| Author | S. Fronzek |
| Author | R. Aikasalo |
| Author | M. Trnka |
| Author | A. Ristolainen |
| Author | T. R. Carter |
| URL | http://www.sciencedirect.com/science/article/pii/S1161030111000694 |
| Volume | 35 |
| Issue | 4 |
| Pages | 205-214 |
| Publication | European Journal of Agronomy |
| ISSN | 1161-0301 |
| Date | November 2011 |
| Journal Abbr | European Journal of Agronomy |
| DOI | 10.1016/j.eja.2011.06.003 |
| Accessed | 6. duben 2014 23:00:26 |
| Library Catalog | ScienceDirect |
| Abstract | In research to date, projected climate change has been considered to be beneficial for agriculture under Nordic conditions, where crop production is mainly limited by low temperatures resulting in short growing seasons. However, with the rapid increases in global mean temperature implied at the high end of the uncertainty range of current projections, which are typically amplified at high latitudes, conditions for crop production could change so dramatically that yields would be reduced, even accounting for the positive effects of CO2 fertilization. In this study, we used the WOFOST crop growth simulation model to examine crop yield responses to a set of plausible scenarios of climate change for Finland up to 2100, including some that exceed 4 °C global mean temperature increase relative to pre-industrial. We selected spring barley (Hordeum vulgare L.) as an indicator crop and calculated water-limited yields for two Finnish locations, Jokioinen and Jyväskylä and for a clay and a sandy soil. Scenarios included systematic increases in temperatures, changes in precipitation distribution and altered daily climatic variability using the M&Rfi weather generator. We also examined the effectiveness of a few adaptation options, such as shifts in sowing dates and hypothetical new crop cultivars. Increasing temperature reduced total growth duration and yield considerably, even with adjusted earlier sowing. A reduced number of rainy days had marked negative effects only in combination with increases in temperature of 4 °C or greater, leading to distinctly higher yield losses on the sandy soil than on the clay. Prolonged dry spells clearly increased yield variability. For scenarios with temperature increases of +6 °C and + 7°C, yield losses at Jokioinen were highest; losses at Jyväskylä were generally less pronounced. Neither CO2 fertilization nor adjusted sowing could compensate the yield losses from temperature changes exceeding +4 °C. On clay soils, yield loss could be compensated by new cultivars. For sandy soils even with new cultivars, there would be yield loss at temperature increases exceeding +3 °C. It can be concluded that the positive effects of climate warming and elevated CO2 concentrations on cereal production at high latitudes are likely to be reversed at temperature increases exceeding 4 °C, with a high risk of marked yield loss. Only plant breeding efforts aimed at increasing yield potential jointly with drought resistance and adjusted agronomic practices, such as sowing, and adequate nitrogen fertilizer management and plant protection, holds a prospect of partly restoring yield levels and reducing the risks of yield shortfall. |
| Short Title | What would happen to barley production in Finland if global warming exceeded 4 °C? |
| Date Added | 6. duben 2014 23:00:26 |
| Modified | 6. duben 2014 23:00:26 |
| Type | Journal Article |
|---|---|
| Author | Eva Svobodová |
| Author | Miroslav Trnka |
| Author | Martin Dubrovský |
| Author | Daniela Semerádová |
| Author | Josef Eitzinger |
| Author | Petr Štěpánek |
| Author | Zdeněk Žalud |
| URL | http://doi.wiley.com/10.1002/ps.3622 |
| Pages | n/a-n/a |
| Publication | Pest Management Science |
| ISSN | 1526498X |
| Date | 09/2013 |
| DOI | 10.1002/ps.3622 |
| Accessed | 6. duben 2014 23:31:00 |
| Library Catalog | CrossRef |
| Language | en |
| Short Title | Determination of areas with the most significant shift in persistence of pests in Europe under climate change |
| Date Added | 6. duben 2014 23:31:00 |
| Modified | 6. duben 2014 23:31:00 |
| Type | Journal Article |
|---|---|
| Author | M. Trnka |
| Author | E. Kocmánková |
| Author | J. Balek |
| Author | J. Eitzinger |
| Author | F. Ruget |
| Author | H. Formayer |
| Author | P. Hlavinka |
| Author | A. Schaumberger |
| Author | V. Horáková |
| Author | M. Možný |
| Author | Z. Žalud |
| URL | http://www.sciencedirect.com/science/article/pii/S0168192310001218 |
| Volume | 150 |
| Issue | 7–8 |
| Pages | 1115-1127 |
| Publication | Agricultural and Forest Meteorology |
| ISSN | 0168-1923 |
| Date | July 15, 2010 |
| Journal Abbr | Agricultural and Forest Meteorology |
| DOI | 10.1016/j.agrformet.2010.04.012 |
| Accessed | 6. duben 2014 23:01:04 |
| Library Catalog | ScienceDirect |
| Abstract | This study was aimed to develop, test and provide access to a snow cover model for agrometeorological use (snowMAUS) that would rely strictly on the weather data used by all crop simulation models, i.e., diurnal temperature extremes and total daily precipitation. Such snow model can easily be used to preprocess input data in order to account for the presence or absence of snow cover whenever required by the crop modeler, without necessitating the acquisition of additional data. The snow cover model was tested across 65 sites across Austria with considerable variability in elevation (155–3111 m a.s.l.). In addition 7 sites in the Czech Republic were used to evaluate snowMAUS reliability in assessing frost damage to winter wheat crop. For illustration a case study documenting the benefit of coupling snowMAUS with process based crop model (STICS) was also included in the study. The presented work complements previous snow cover modeling studies with its focus on the development of a simple snow cover model for areas under intensive agricultural use (mostly lowlands) with 65% of stations providing weather data being located at altitudes below 800 m. The presented results proved that SnowMAUS can estimate with reasonable precision snow cover presence/absence, and to a large extent snow cover depth. The model also accurately represented seasonal variations in the number of snow days or in the volume of precipitation in the form of snow. The simplicity of the model and the fact that it relies only on the daily data is a great advantage. We have demonstrated that in areas with a high probability of winter temperatures dropping below frost-tolerance thresholds and that tend to have considerable snow cover (e.g., Central Europe), the information about snow cover presence/absence is essential for estimating potential frost damage to winter crops. The snow cover model tested in this study could be easily implemented in most crop growth models and would enhance their performance in the Central European region. The up-to-date version of the model is freely available to users in the scientific community, which should allow for model testing in different climate conditions and application with various types of agrometeorological models. |
| Date Added | 6. duben 2014 23:01:04 |
| Modified | 6. duben 2014 23:01:04 |
| Type | Journal Article |
|---|---|
| Author | M. Trnka |
| Author | Jørgen Eivind Olesen |
| Author | K. C. Kersebaum |
| Author | A. O. Skjelvåg |
| Author | J. Eitzinger |
| Author | B. Seguin |
| Author | P. Peltonen-Sainio |
| Author | R. Rötter |
| Author | Ana Iglesias |
| Author | S. Orlandini |
| Author | M. Dubrovský |
| Author | P. Hlavinka |
| Author | J. Balek |
| Author | H. Eckersten |
| Author | E. Cloppet |
| Author | P. Calanca |
| Author | A. Gobin |
| Author | V. Vučetić |
| Author | P. Nejedlik |
| Author | S. Kumar |
| Author | B. Lalic |
| Author | A. Mestre |
| Author | F. Rossi |
| Author | J. Kozyra |
| Author | V. Alexandrov |
| Author | D. Semerádová |
| Author | Z. Žalud |
| URL | http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02396.x/abstract |
| Rights | © 2011 Blackwell Publishing Ltd |
| Volume | 17 |
| Issue | 7 |
| Pages | 2298-2318 |
| Publication | Global Change Biology |
| ISSN | 1365-2486 |
| Date | July 1, 2011 |
| DOI | 10.1111/j.1365-2486.2011.02396.x |
| Accessed | 6. duben 2014 23:19:20 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | To date, projections of European crop yields under climate change have been based almost entirely on the outputs of crop-growth models. While this strategy can provide good estimates of the effects of climatic factors, soil conditions and management on crop yield, these models usually do not capture all of the important aspects related to crop management, or the relevant environmental factors. Moreover, crop-simulation studies often have severe limitations with respect to the number of crops covered or the spatial extent. The present study, based on agroclimatic indices, provides a general picture of agroclimatic conditions in western and central Europe (study area lays between 8.5°W–27°E and 37–63.5°N), which allows for a more general assessment of climate-change impacts. The results obtained from the analysis of data from 86 different sites were clustered according to an environmental stratification of Europe. The analysis was carried for the baseline (1971–2000) and future climate conditions (time horizons of 2030, 2050 and with a global temperature increase of 5 °C) based on outputs of three global circulation models. For many environmental zones, there were clear signs of deteriorating agroclimatic condition in terms of increased drought stress and shortening of the active growing season, which in some regions become increasingly squeezed between a cold winter and a hot summer. For most zones the projections show a marked need for adaptive measures to either increase soil water availability or drought resistance of crops. This study concludes that rainfed agriculture is likely to face more climate-related risks, although the analyzed agroclimatic indicators will probably remain at a level that should permit rainfed production. However, results suggests that there is a risk of increasing number of extremely unfavorable years in many climate zones, which might result in higher interannual yield variability and constitute a challenge for proper crop management. |
| Date Added | 6. duben 2014 23:19:20 |
| Modified | 6. duben 2014 23:19:20 |
| Type | Journal Article |
|---|---|
| Author | M. Trnka |
| Author | F. Muška |
| Author | D. Semerádová |
| Author | M. Dubrovský |
| Author | E. Kocmánková |
| Author | Z. Žalud |
| URL | http://www.sciencedirect.com/science/article/pii/S0304380007002414 |
| Volume | 207 |
| Issue | 2–4 |
| Pages | 61-84 |
| Publication | Ecological Modelling |
| ISSN | 0304-3800 |
| Date | October 10, 2007 |
| Journal Abbr | Ecological Modelling |
| DOI | 10.1016/j.ecolmodel.2007.04.014 |
| Accessed | 6. duben 2014 23:20:24 |
| Library Catalog | ScienceDirect |
| Abstract | Predicting the potential distribution of agricultural pests, both indigenous and introduced, plays a key role in determining the impact of global change on agricultural, horticultural and forestry ecosystems. This study investigates changes in the climatic niche of one of the most important agricultural pests, the European Corn Borer (Ostrinia nubilalis, Hubner), using the multi-generational phenology model ECAMON. The model enables us to predict the development of the European Corn Borer (ECB), to estimate the risk of its establishing a permanent population, and to give an indication of climate-related stress factors affecting the species. The evaluation of ECAMON demonstrated that it provides accurate predictions of the onset and duration of the key phenological stages over a broad range of sites. It explains over 70% of the variation in the timing of key developmental stages based only on daily weather data. ECAMON simulations correctly predicted the presence/absence of the ECB over the study region during the 1961–1990 reference period. It also helped to explain the sudden increase in the maize infestation over the territory of the Czech Republic during the unusually warm period of 1991–2000. The ECAMON results demonstrated that the effect of climate will be significant and complex. According to our estimates, the extent of the climate niche will expand within the next 20–30 years to cover almost the entire area suitable for agriculture by 2040–2075. The establishment of a bivoltine population is not imminent within the next decade, but it is likely to take place during the period of 2025–2050. The timing and extent of these changes will be affected not only by changes in the means of key meteorological parameters, but also in their variability. These shifts will be clearly accompanied by an earlier onset of key developmental stages of the pest. The study demonstrated that the level of uncertainty caused both by emission scenarios and by differences in global circulation models (GCMs) are of the same order of magnitude. Thus, only the combination of a wide range of emission scenarios and GCMs can provide insight into the potential effect of climate change on any particular species. Under future climate conditions, grain maize is expected to partly replace traditional cereals (e.g. winter wheat, rye, etc.); thus the establishment of a national or international monitoring scheme is desirable, and an ECAMON-like tool might serve as the basic modeling platform for such an effort. |
| Short Title | European Corn Borer life stage model |
| Date Added | 6. duben 2014 23:20:24 |
| Modified | 6. duben 2014 23:20:24 |
| Type | Journal Article |
|---|---|
| Author | M. Trnka |
| Author | J. Eitzinger |
| Author | P. Hlavinka |
| Author | M. Dubrovsky |
| Author | D. Semeradova |
| Author | P. Stepanek |
| Author | S. Thaler |
| Author | Z. Zalud |
| Author | M. Mozny |
| Author | H. Formayer |
| URL | http://agris.fao.org/agris-search/search.do?f=2009/CZ/CZ0907.xml;CZ2009000825 |
| Volume | 55 |
| Issue | 6 |
| Pages | 257-266 |
| Publication | Plant, Soil and Environment - UZEI (Czech Republic) |
| ISSN | 1214-1178 |
| Date | Jun 2009 |
| Accessed | 6. duben 2014 23:23:21 |
| Library Catalog | agris.fao.org |
| Language | English |
| Abstract | The presented work complements studies on agroclimatic zoning that were performed during 19th and 20th century in the Czech Republic and Austria and allows estimating the effect of climate change on the spatial distribution of agroclimatic conditions within both countries. The main conclusions of the study are: (1) The combination of increased air temperature and changes in the amount and distribution of precipitation will lead to significant shifts in the agroclimatic zones by the 2020's. The current most productive areas will be reduced and replaced by warmer but drier conditions, which are considered less suitable for rainfed farming. (2) While trends in the changes expected in lowlands are mostly negative (especially for non-irrigated crops), higher elevations might experience improvement in their agroclimatic production potential. However, the production potential of these regions is usually limited by other factors such as the soil quality and terrain accessibility. Additionally, these positive effects might be short-lived, as by the 2050's, even the areas in higher altitudes might experience much drier conditions than nowadays. (3) Dairy-oriented agriculture (based on permanent grassland production) at higher altitudes could suffer through an increased evapotranspiration demand combined with a decrease in precipitation, leading to higher water deficits and yield variations. (4) All above listed changes will most likely occur within less than four decades. The rate of change might be so high that the concept of agroclimatic zoning itself might lose its relevance due to the perpetual change. |
| Date Added | 6. duben 2014 23:23:21 |
| Modified | 6. duben 2014 23:27:28 |
| Type | Journal Article |
|---|---|
| Author | Miroslav Trnka |
| Author | Jan Kyselý |
| Author | Martin Možný |
| Author | Martin Dubrovský |
| URL | http://onlinelibrary.wiley.com/doi/10.1002/joc.1703/abstract |
| Rights | Copyright © 2008 Royal Meteorological Society |
| Volume | 29 |
| Issue | 5 |
| Pages | 655-672 |
| Publication | International Journal of Climatology |
| ISSN | 1097-0088 |
| Date | April 1, 2009 |
| Journal Abbr | Int. J. Climatol. |
| DOI | 10.1002/joc.1703 |
| Accessed | 7. duben 2014 21:56:01 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | Relationships between the soil moisture availability atmospheric and the atmospheric circulation in Central Europe were analyzed for the period 1881–2005. The analysis was based on the Hess-Brezowsky catalogue of circulation types and series of weekly self-calibrated Palmer Z-index (scZ-index) and Palmer Drought Severity index (scPDSI) at seven stations where high-quality daily data had recently become available. The results show that the large scale droughts during spring months (MAM) were associated with east (E), south (S), and south-east (SE) Grosswettertypen (GWT), whereas during summer (JJA) and the whole growing season, i.e., April-September (VEG), the Central Europe high pressure systems (HM) and east (E) GWT were conducive to drought. Statistically significant drying trends were noted at a majority of the stations, especially during MAM and JJA over the whole period for which the scPDSI and scZ-index series were available (1875–2005). Although almost no statistically significant tendencies were found prior to 1940, after this year a significant tendency towards more intense drought was present at all sites. The largest drying trend was noted during the VEG and AMJ seasons. The overall drying trend might be associated with shifts in the GWT frequency, especially during AMJ. Although the aggregate frequency of occurrence of drought conducive GWT (i.e. E, S and HM) remained stable at approximately 30% up to the 1940s, afterwards a steady increase to the present 55% is observed. Higher frequencies of S and HM types drove the observed increase of drought conducive GWT at the expense of N types that are associated with wet conditions. The long-term shifts in the frequency of circulation types conducive to drought explain more than 50% of the long-term variations of both scZ-index and PDSI values over the territory of the Czech Republic, and they are likely to affect neighboring regions as well. Copyright © 2008 Royal Meteorological Society |
| Date Added | 7. duben 2014 21:56:01 |
| Modified | 7. duben 2014 21:56:01 |
| Type | Journal Article |
|---|---|
| Author | R. Wilson |
| Author | R. D'Arrigo |
| Author | B. Buckley |
| Author | U. Büntgen |
| Author | J. Esper |
| Author | D. Frank |
| Author | B. Luckman |
| Author | S. Payette |
| Author | R. Vose |
| Author | D. Youngblut |
| URL | http://onlinelibrary.wiley.com/doi/10.1029/2006JD008318/abstract |
| Rights | Copyright 2007 by the American Geophysical Union. |
| Volume | 112 |
| Issue | D17 |
| Pages | D17103 |
| Publication | Journal of Geophysical Research: Atmospheres |
| ISSN | 2156-2202 |
| Date | September 16, 2007 |
| Journal Abbr | J. Geophys. Res. |
| DOI | 10.1029/2006JD008318 |
| Accessed | 7. duben 2014 13:58:16 |
| Library Catalog | Wiley Online Library |
| Language | en |
| Abstract | No current tree ring (TR) based reconstruction of extratropical Northern Hemisphere (ENH) temperatures that extends into the 1990s captures the full range of late 20th century warming observed in the instrumental record. Over recent decades, a divergence between cooler reconstructed and warmer instrumental large-scale temperatures is observed. We hypothesize that this problem is partly related to the fact that some of the constituent chronologies used for previous reconstructions show divergence against local temperatures in the recent period. In this study, we compiled TR data and published local/regional reconstructions that show no divergence against local temperatures. These data have not been included in other large-scale temperature reconstructions. Utilizing this data set, we developed a new, completely independent reconstruction of ENH annual temperatures (1750–2000). This record is not meant to replace existing reconstructions but allows some degree of independent validation of these earlier studies as well as demonstrating that TR data can better model recent warming at large scales when careful selection of constituent chronologies is made at the local scale. Although the new series tracks the increase in ENH annual temperatures over the last few decades better than any existing reconstruction, it still slightly under predicts values in the post-1988 period. We finally discuss possible reasons why it is so difficult to model post-mid-1980s warming, provide some possible alternative approaches with regards to the instrumental target and detail several recommendations that should be followed in future large-scale reconstruction attempts that may result in more robust temperature estimates. |
| Short Title | A matter of divergence |
| Date Added | 7. duben 2014 13:58:16 |
| Modified | 7. duben 2014 13:58:16 |
| Type | Journal Article |
|---|---|
| Author | Pascal Yiou |
| Author | Pierre Ribereau |
| Author | Philippe Naveau |
| Author | Marta Nogaj |
| Author | Rudolf Brázdil |
| URL | http://www.tandfonline.com/doi/abs/10.1623/hysj.51.5.930 |
| Volume | 51 |
| Issue | 5 |
| Pages | 930-945 |
| Publication | Hydrological Sciences Journal |
| ISSN | 0262-6667 |
| Date | 2006 |
| DOI | 10.1623/hysj.51.5.930 |
| Accessed | 7. duben 2014 22:00:48 |
| Library Catalog | Taylor and Francis+NEJM |
| Abstract | Abstract This study focuses on two main rivers of Bohemia (Czech Republic): the Vltava and the Elbe. Flows are determined for the Elbe at Děčín (discharges) and Litoměřice (water stages), and for the Vltava at Prague (discharges). Extreme flows have an important socio—economic impact; hence modelling their occurrence accurately is crucial. We identify the meteorological causes for floods: (a) the winter type due to snowmelt, ice damming, and usually rain, and (b) the summer type due to continuous heavy rains. The amplitude and frequency of floods are analysed using extreme value theory, in a non-stationary context. This allows the determination of the trends of flood features during the instrumental period and their dependence on atmospheric circulation patterns. |
| Date Added | 7. duben 2014 22:00:48 |
| Modified | 7. duben 2014 22:10:27 |