HR: 0800h
AN: GC11A-0125    [Abstracts]
TI: Changes in Central European Soil Moisture Availability and Atmospheric Circulation Patterns between 1875 and 2005 - Regional Climate Change in Progress?
AU: * Trnka, M
EM: mirek_trnka@yahoo.com
AF: Institute for Agrosystems and Bioclimatology, Mendel University of Agriculture and Forestry Brno Zemedelska 1, Brno, 61300, Czech Republic
AU: * Trnka, M
EM: mirek_trnka@yahoo.com
AF: Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic Bocni II 1401, Prague, 14131, Czech Republic
AU: Kysely, J
EM: honza@ufa.cas.cz
AF: Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic Bocni II 1401, Prague, 14131, Czech Republic
AU: Dubrovsky, M
EM: dub@ufa.cas.cz
AF: Institute for Agrosystems and Bioclimatology, Mendel University of Agriculture and Forestry Brno Zemedelska 1, Brno, 61300, Czech Republic
AU: Dubrovsky, M
EM: dub@ufa.cas.cz
AF: Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic Bocni II 1401, Prague, 14131, Czech Republic
AU: Mozny, M
EM: martin.mozny@chmi.cz
AF: Czech Hydrometeorological Institute, Na Sabatce 17, Komorany, Prague, 14306, Czech Republic
AU: Hostynek, J
EM: hostynek@chmi.cz
AF: Czech Hydrometeorological Institute, Na Sabatce 17, Komorany, Prague, 14306, Czech Republic
AU: Svoboda, M
EM: msvoboda@unlnotes.unl.edu
AF: National Drought Mitigation Center, of Natural Resources, University of Nebraska 819 Hardin Hall 3310 Holdrege St, Lincoln, 68583, United States
AU: Hayes, M J
EM: mjhayes@unlnotes.unl.edu
AF: National Drought Mitigation Center, of Natural Resources, University of Nebraska 819 Hardin Hall 3310 Holdrege St, Lincoln, 68583, United States
AU: Zalud, Z
EM: zalud@mendelu.cz
AF: Institute for Agrosystems and Bioclimatology, Mendel University of Agriculture and Forestry Brno Zemedelska 1, Brno, 61300, Czech Republic
AB: Relationships between the soil moisture availability 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 (CTs), and a series of weekly self-calibrated Palmer Z-index (scZ-index) and Palmer Drought Severity Index (scPDSI) values at seven stations where high-quality daily data has 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) circulation types, whereas during summer (JJA) and the whole vegetation season, i.e., April-September (VEG), the Central Europe high pressure systems (HM) and east (E) circulation types 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, a significant tendency towards more intense drought was present at all sites after this year. The largest drying trend was noted during the VEG and AMJ seasons. The overall drying trend might be associated with shifts in the frequency of CTs, especially during AMJ. Although the aggregate frequency of occurrence of drought-conducive CTs (i.e. E, S and HM) remained stable at approximately 30% up to the 1940s, a steady increase to the present 55% frequency is observed afterwards. Higher frequencies of S and HM types drove the observed increase of drought-conducive CTs 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 whole central European region as well. Acknowledgement: This study was conducted with support of the 6th FP EU research project CECILIA (no GOCE 037005) and by the Research plan No. MSM6215648905 "Biological and technological aspects of sustainability of controlled ecosystems and their adaptability to climate change", which is financed by the Ministry of Education, Youth and Sports of the Czech Republic. The weekly drought indicators were parameterized with the help of KONTAKT project no. ME 844.
DE: 1637 Regional climate change
DE: 1812 Drought
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3319 General circulation (1223)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting