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Impacts of hydrometeorological extremes in South Moravia based on documentary evidence
Chromá, Kateřina; Dolák, Lukáš; Brázdil, Rudolf; Řezníčková, Ladislava
2017 - English
Hydrometeorological extremes have influenced human lives significantly in the past, just as they continue\nto do today. To analyse these influences in the past, information is needed from before the start of systematic\nmeteorological and hydrological observations. Documentary evidence constitutes a very rich source of\ninformation about past hydrometeorological extremes. This paper focuses on impacts of hydrometeorological\nextremes on agriculture and material property and their socio-economic consequences. It also discusses\nthe potential and limitations of such documentary evidence. Despite documentary evidence’s several\nlimitations (e.g. spatial and temporal uncertainty, uncertainty in the annual distribution of records, in\nthe type of extreme, etc.), it is a promising source of information useful for future studies.
Keywords:
documentary evidence; hydrometeorological extremes; impacts; South Moravia
Available at various institutes of the ASCR
Impacts of hydrometeorological extremes in South Moravia based on documentary evidence
Hydrometeorological extremes have influenced human lives significantly in the past, just as they continue\nto do today. To analyse these influences in the past, information is needed from before the ...
Comparison of leaf area index dynamics and radiation use efficiency of C3 crops in the Czech Republic
Tripathi, Abishek; Pohanková, Eva; Trnka, Miroslav; Klem, Karel
2017 - English
Leaf area index (LAI) and radiation use efficiency (RUE) are key parameters for plant growth and productivity.\nBecause of irregularities in weather conditions, accurate estimation of crop production requires\nunderstanding relationships between weather, LAI, RUE, and final production. It is thus important to\nstudy how the LAI dynamics, leaf area duration (LAD), and RUE are related to aboveground biomass production\nfor different crops. In our study, we compared aboveground dry mass production, LAI dynamics,\nRUE, and LAD in three C3 crops (spring barley [SB], winter wheat [WW], and oilseed rape [OSR]) in the\nCzech Republic. LAI was measured on the basis of transmitted photosynthetically active radiation, LAD\nwas calculated by counting the number of days in the growing season, RUE was measured using Beer’s\nlaw, and the aboveground dry mass was estimated at the time of harvest. Results of our study showed high\nbiomass production and RUE in SB while there was highest maximum LAI (LAImax) and LAD in OSR. We\nconcluded that LAI dynamics or LAImax do not fully reflect the crop production and that RUE may be considered\nas a better indicator for aboveground dry mass production.
Keywords:
leaf area; index dynamics; radiations use efficiency; Czech Republic
Available at various institutes of the ASCR
Comparison of leaf area index dynamics and radiation use efficiency of C3 crops in the Czech Republic
Leaf area index (LAI) and radiation use efficiency (RUE) are key parameters for plant growth and productivity.\nBecause of irregularities in weather conditions, accurate estimation of crop production ...
Stem emissions from poplar hybrids grown in a shortrotation plantation contribute to ecosystem balance of nitrous oxide and methane
Macháčová, Kateřina; Kreuzwieser, J.; Rennenberg, H.
2017 - English
The expansion of short-rotation coppices (SRCs) of fast-growing trees can affect the global balance of greenhouse\ngases (GHGs). These include not only carbon dioxide (CO2) but also methane (CH4) and nitrous oxide\n(N2O), both naturally produced by soil microorganisms. Trees are known to exchange CH4 and N2O with\nthe atmosphere. To date, however, the fluxes of these gases from fast-growing trees have been excluded from\nestimation of the GHGs balance for SRCs. Our objectives were to quantify and scale up CH4 and N2O fluxes\nfrom stems of the fast-growing poplar hybrids Max4 and Monviso at an SRC in southwest Germany. Our\ncase study shows that the stems of both hybrids were sources of N2O and CH4, even though consumption of\nCH4 was also observed. The hybrids did not differ in their exchange capacity. Nitrogen fertilization resulted in\nhigher stem N2O emissions compared to non-fertilized trees. The emissions of N2O and CH4 from stems contributed\nas much as 1.5% and 1.2% of soil N2O emission and soil CH4 uptake, respectively.
Keywords:
stem emission; poplar hybrids grown; short-rotation plantation; ecosystem balance; nitrous oxide
Available at various institutes of the ASCR
Stem emissions from poplar hybrids grown in a shortrotation plantation contribute to ecosystem balance of nitrous oxide and methane
The expansion of short-rotation coppices (SRCs) of fast-growing trees can affect the global balance of greenhouse\ngases (GHGs). These include not only carbon dioxide (CO2) but also methane (CH4) and ...
Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces
Fischer, Milan; Katul, G.; Pozníková, Gabriela; Noormets, A.; Domec, J.-C.; Trnka, Miroslav; King, J.
2017 - English
Two alternative micrometeorological methods, flux-variance (FV) and surface renewal (SR), based on\nmeasurements of high-frequency temperature fluctuation and Obukhov length stability parameter, were\ntested against eddy covariance (EC) sensible heat flux (H) measurements. The study was conducted at\nthree sites representing agricultural, forestry, and agroforestry systems. In terms of measurement setup,\nthese sites represented surface, roughness, and canopy top layer, respectively. As expected, the best match\nof all the methods was in the surface layer, whilst it was poorer in the roughness and canopy sublayers.\nSystematic deviation from EC across all three investigated surfaces was within 16% and 8% for FV and SR,\nrespectively. While FV resulted in higher correlation with EC measurements (0.93–0.98 vs. 0.89–0.97),\nSR provided less systematic biases (1.02–1.08 vs. 0.94–1.16). In general, both FV and SR provided slightly\nhigher H as compared to EC. We suggest that parallel deployment of FV and SR is useful, as both methods\nrequire the same instrumentation yet they are based on sufficiently different theories. Therefore, the agreement\nbetween FV and SR increases confidence in the results obtained and vice versa.
Keywords:
Temperature fluctuation; flux variance; agriculture and forest surface
Available at various institutes of the ASCR
Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces
Two alternative micrometeorological methods, flux-variance (FV) and surface renewal (SR), based on\nmeasurements of high-frequency temperature fluctuation and Obukhov length stability parameter, ...
Do Invasive Alien Species Affect Diversity of Local Communities?
Kindlmann, Pavel; Honěk, A.; Martinková, Z.
2017 - English
Here we present results of simulation models to investigate the diversity dynamics in a theoretical system consisting of an "original" community of native species and an invasive alien species that invades this community, thus creating a "new" community. See Kindlmann et al. (2017) for full details of the simulations and results.
Keywords:
invasive species; local diversity
Available at various institutes of the ASCR
Do Invasive Alien Species Affect Diversity of Local Communities?
Here we present results of simulation models to investigate the diversity dynamics in a theoretical system consisting of an "original" community of native species and an invasive alien species that ...
Výskyt silných mrazů koncem měsíce dubna 2016 s ohledem na škody způsobené v ovocnářství
Zahradníček, Pavel; Rožnovský, J.; Štěpánek, Petr; Chuchma, F.
2017 - Czech
Výskyty teplot vzduchu pod bodem mrazu na počátku a konci vegetace, tedy výskyty tzv. vegetačních mrazů, byly vždy v našich klimatických podmínkách nebezpečím. Zima 2015/2016 byla relativně teplá, podobně také počátek jara a též měsíc duben. Vysoké škody v sadech způsobilo prudké ochlazení od 25. do 30. dubna 2016, kdy se na naše území dostal velmi studený vzduch od severu. Minimální teploty v noci a ráno klesly pod bod mrazu. Příliv studeného vzduchu začal 19. 4. 2016, ale pod bodem mrazu byly jen přízemní teploty vzduchu. Ovšem v období 25. až 30. 4. 2016 poklesly pod 0°C i teploty vzduchu měřené ve 2 metrech. Na celém území ČR byla nejnižší naměřená minima pod bodem mrazu a nejčastěji se pohybovala mezi -2 až -4°C. Nejnižší minimální přízemní teploty vzduchu za dané období klesly pod -5°C na 85 % území ČR. Na Moravě byla přízemní minimální teplota vzduchu nižší než 0°C v pěti dnech, v Čechách každý den ze sledovaného období 25. až 30. 4. 2016. Je nutné zdůraznit, že v době květu ovocných stromů bez listů tvoří květy aktivní povrch. Vyzařováním jsou teploty květů často ještě nižší než naměřená minima přízemní teploty vzduchu. V tomto hodnocení není zahrnut vliv reliéfu, díky kterému dochází k výskytu mrazových kotlin. Air temperatures below 0°C, the so-called vegetation period frosts, have always been a problem in the climate conditions of the Czech Republic. The 2015/2016 winter as relatively mild, as well as the following beginning of spring and April. Major damages were caused by sudden rapid drop in air temperatures in the period between 25th and 30th April 2016, as a result of very cold air from the North. Air temperature began to fall on 19th April 2016, but only ground temperatures were below freezing point. Between 25th and 30th April, however, even air temperatures measured at 2m above the ground dropped below 0°C. All over the country, the minimum temperatures were below 0°C, usually between -2 and -4°C. The lowest minimum ground air temperatures were below -5°C at 85% of the area of the Czech Republic. In Moravia, the minimum ground air temperature was below 0°C on five days, in Bohemia it was every day in the period between 25th and 30th April 2016. It should be emphasized that during the flowering time of fruit trees without leaves, the flowers form an active surface. Due to radiation the flower temperature is often even lower than the measured ground air temperature minimum. This analysis does not include the effects of terrain, which determines positions of frost basins.
Keywords:
vegetation period frost; minimum ground air temperature; April 2016; fruit farming
Available at various institutes of the ASCR
Výskyt silných mrazů koncem měsíce dubna 2016 s ohledem na škody způsobené v ovocnářství
Výskyty teplot vzduchu pod bodem mrazu na počátku a konci vegetace, tedy výskyty tzv. vegetačních mrazů, byly vždy v našich klimatických podmínkách nebezpečím. Zima 2015/2016 byla relativně teplá, ...
Highly time resolved measurement of atmospheric elemental and organic carbon at a typical background site in Central Europe.
Mbengue, Saliou; Fusek, M.; Schwarz, Jaroslav; Holoubek, Ivan
2017 - English
Atmospheric organic (OC) and elemental (EC) carbon play an important role in atmospheric chemistry, climate change and public health. There have been relatively few studies dealing with EC and OC in rural background sites which are less influenced by urban and industrial emissions. Nevertheless, measurements at background areas are important for understanding the transport and transformation characteristics of anthropogenic air pollutants, and their effects on various aspects of regional and global environment changes. In this study, we focus on variability of EC and OC concentrations (considering various day categories and seasons) from a rural background site which is representative for Central European rural areas.\n
Keywords:
organic carbon and elemental carbon; rural background; OC/EC ratio; variability
Fulltext is available at external website.
Highly time resolved measurement of atmospheric elemental and organic carbon at a typical background site in Central Europe.
Atmospheric organic (OC) and elemental (EC) carbon play an important role in atmospheric chemistry, climate change and public health. There have been relatively few studies dealing with EC and OC in ...
Využití modelů Euro-CORDEX pro predikci sucha s ohledem na holomrazy a srážkový deficit v chladném období roku
Potopová, V.; Štěpánek, Petr; Zahradníček, Pavel; Farda, Aleš; Türkot, L.; Hiřmanová, D.
2017 - Czech
Příspěvek se zaměřuje na analýzu změny v rozložení četnosti, délky trvání a závažnosti sucha v různých časových měřítkách pro historické i budoucí běhy regionálních klimatických modelů v rámci aktivity Euro-CORDEX. Analýzy jsou založené na experimentech se scénáři vývoje skleníkových plynů RCP4.5 a RCP8.5 v budoucích obdobích 2041 - 2070 a 2071 - 2100 včetně porovnání s referenčním obdobím 1981 - 2010. Pro kvantifikaci sucha byl z řady různých charakteristik zvolen standardizovaný srážkový evapotranspirační index (SPEI) a standardizovaný srážkový index (SPI) v pěti časových intervalech – 1, 3, 6, 12 a 24 měsíců. Odhady budoucích projekcí sucha dle SPI, mají tendenci podceňovat rizika sucha, zatímco riziko závažnosti sucha dle SPEI se zvyšuje do konce tohoto století, i přes mírný nárůst srážek. This paper focuses on the analysis of changes in the distribution of frequency, duration and magnitude of drought for various time scales for two future time periods, 2041 - 2070 and 2071 - 2100 and compared to the reference period 1981 - 2010 under the two Representative Concentration scenarios RCP4.5 and RCP8.5. Dry events are calculated and analysed according to the classification of the standardized precipitation evapotranspiration index (SPEI) and the standardized precipitation index (SPI). Estimates of future drought projections based on the SPI tend to underestimate risk, while risk of the SPEI drought magnitude increases by the end of the century, even if precipitation increases moderately.
Keywords:
regional climate models; SPEI; SPI; RCP4.5; RCP8.5
Available at various institutes of the ASCR
Využití modelů Euro-CORDEX pro predikci sucha s ohledem na holomrazy a srážkový deficit v chladném období roku
Příspěvek se zaměřuje na analýzu změny v rozložení četnosti, délky trvání a závažnosti sucha v různých časových měřítkách pro historické i budoucí běhy regionálních klimatických modelů v rámci ...
Stanovení a změna tuhosti jednotlivých zim za období 1961-2015
Zahradníček, Pavel; Rožnovský, J.; Brzezina, J.; Štěpánek, Petr; Farda, Aleš; Chuchma, F.; Potopová, V.
2017 - Czech
Hodnoty minimálních teplot vzduchu v chladném období, ale zvláště v zimě mají často velmi negativní dopady na celý soubor našich aktivit. Je mnoho dokladů z předcházejících let, kdy prudké ochlazení způsobilo škody na technice, zastavilo dopravu apod. Každou zimní sezónu či chladný půlrok lze ohodnotit podle několika parametrů. Pro tento článek byly vybrány tři klimatické charakteristiky. První je základní, a to průměrná teplota vzduchu. Dále byla použita suma efektivních teplot vzduchu pod 0°C a -5°C. Poslední charakteristikou, která určuje extremitu daného roku, je absolutní minimální teplota vzduchu. U všech parametrů byla provedena časoprostorová analýza. K největší statisticky významné změně dochází u průměrné teploty vzduchu, kdy od roku 1961 dochází k postupnému oteplování. Velký vliv na teploty vzduchu v zimních měsících má kontinentalita podnebí, kdy v Čechách se otepluje rychleji než na Moravě a zároveň na západním okraji republiky jsou nejnižší absolutní minimální teploty vzduchu. Při víceparametrické analýze klimatických charakteristik vyšel jako rok s nejchladnější zimou a chladným půlrokem rok 1963. Naopak nejméně drsná zima byla v roce 2007. Podle klimatologických modelů lze očekávat zimy do roku 2100 v průměru teplejší o 2,4 °C až 4,9 °C, což by znamenalo výraznou změnu dosavadních zimních podmínek. Values of the minimum air temperatures during cold periods, especially winter, have often negative impacts on a wide range of human activities. In the past there have been many cases when rapid decrease in air temperature caused damages to machines, halted traffic etc. Every winter or cold half-year can be assessed using several parameters. In this article, three climatological characteristics were used. First was the average air temperature. Second was the sum of effective air temperatures below 0°C and -5°C. Last characteristic, which determines the extremity of that particular period, is the absolute minimum air temperature. Space-time analysis was performed for all the three characteristics. Statistically, the most significant change was found in case of the average air temperature – there is a gradual warming since 1961. Air temperatures during winter are to a large extent affected by the continentality of the climate. In Bohemia, the warming is faster than in Moravia and the western part of the country has the lowest absolute minimum air temperatures. Using multiparametric analysis of climatological characteristics it was found that the coldest winter and coldest half-year from the analyzed years was in 1963. In contrast, mildest winter was in 2007. Current climatological models predict that winter temperatures by the end of 21st century will be higher by 2.4°C to 4.9°C, which would mean a significant change in the current winter conditions.\n
Keywords:
winter severity; EURO-CORDEX; absolute minimum; effective temperature; winter climate
Available at various institutes of the ASCR
Stanovení a změna tuhosti jednotlivých zim za období 1961-2015
Hodnoty minimálních teplot vzduchu v chladném období, ale zvláště v zimě mají často velmi negativní dopady na celý soubor našich aktivit. Je mnoho dokladů z předcházejících let, kdy prudké ochlazení ...
Mrazové indexy v chladném půlroce na území České republiky
Zahradníček, Pavel; Rožnovský, J.; Brzezina, J.; Štěpánek, Petr; Farda, Aleš; Chuchma, F.; Potopová, V.
2017 - Czech
Největší škody vyvolávají poklesy minimální teploty vzduchu na mimořádně nízké hodnoty. V současné změně klimatu se projevuje růst teplot vzduchu i v zimě, ale tento fakt se nemusí zcela odrážet v poklesu výskytu velice nízkých teplot vzduchu. Vyjádřit jednoduchou charakteristikou průběh teplot vzduchu v chladném období v celé jejich šíři není jednoduché. Meteorology a klimatology jsou využívány různé charakteristiky, které můžeme označit jako mrazové indexy. Cílem tohoto zpracování je analyzovat časoprostorovou změnu standardních mrazových indexů, jako je počet mrazových, ledových a arktických dnů. Jelikož tyto indexy nemusí vždy zcela vyjadřovat reakci přírody na teplotní limit, byly dále zkoumány počty dnů s minimální teplotou vzduchu pod -3, -5, -7, -10, -15 , -20 a -25°C. V posledních 15 letech (2001-2015) byl zaznamenán pokles těchto mrazových indexů oproti normálu 1961-1990, ale ne vždy jde o statisticky významný trend. Ten byl nalezen hlavně u počtu dnů s vyšší teplotní hranicí (mrazový, ledový den a minimální teplota vzduchu nad -3 až -10°C). Naopak dnů s extrémně nízkými teplotami je za rok pouze velmi málo (nebo se objevují jednou za několik let), takže zde hraje dominantní roli spíše variabilita. Součásti článku je i analýza možného vývoje do budoucnosti na základě nejnovější klimatických modelů. The dynamics of air temperatures during cold half-year to a large extent affect all human activities. Most significant damages are caused by minimum air temperatures dropping to very low values. Due to the current ongoing climate change, air temperatures in winter in general are increasing, however, this does not necessarily mean the frequency of these very low temperatures decreases. It is not easy to express the course of air temperatures during cold periods using some simple characteristic. Meteorologists and climatologists use various characteristics, which can be referred to as frost indexes. These include the number of frost, ice or arctic days. Since these indexes not always perfectly reflect reaction of the nature to a particular temperature threshold, the analysis also included number of days with minimum air temperature below -3, -5, -7, -10, -15, -20 and -25°C. In the last 15 years (2001-2015), there has been a decrease in the frost indexes in comparison to the normal period 1961-1990, this trend however, is not always statistically significant. Significant changes were found in particular in case of the number of days with a higher temperature threshold (frost, ice days and minimum air temperature above -3 to -10°C). In contrast, days with extremely low temperatures are relatively rare (sometimes only observed once in several years), so the dominant factor here is rather variability. The paper also includes an analysis of possible future development based on the most recent climatological models.
Keywords:
frost; typical days; trend; EURO-CORDEX; climate change
Available on request at various institutes of the ASCR
Mrazové indexy v chladném půlroce na území České republiky
Největší škody vyvolávají poklesy minimální teploty vzduchu na mimořádně nízké hodnoty. V současné změně klimatu se projevuje růst teplot vzduchu i v zimě, ale tento fakt se nemusí zcela odrážet v ...
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