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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 ...
USE OF NORWAY SPRUCE AS ADMIXTURE IN SUBURBAN FORESTS AT LOWER ALTITUDES
Novosadová, K.; Knott, R.; Szatniewska, Justyna
2017 - English
In suburban forestry there is a need not only to manage a maximum financial result, but also to support recreational and aesthetic forest functions. Thus, these forests need professional treatments in the form of proper silvicultural methods to maintain stand stability. One of these methods is cultivation of mixed stands with Norway spruce. This study examines the mortality of spruce growing in stands in lower forest vegetation zones with time series of 50 years and the changes in biomass production in young variously mixed stands in three different vegetation zones. According to the results, it is beneficial to grow spruce in the range from 5 to 10% of admixture in stand establishment stage. Due to silvicultural treatments and inter species interactions, spruce representation in a stand may increase to 30% in the mature stands. Spruce trees tended this way in young age partly will be outcompeted by other species, but the remaining individuals will adapt to the existing environmental conditions and thus the whole stand will be more stable. Biomass production of spruce trees depends on its representation in the stand. The higher the spruce admixture, the lower will be average spruce tree biomass. The study indicated that in young stands up to 30% of spruce representation, its biomass was up to 100% greater than in spruce monocultures.
Keywords:
growth; climate; europe; stands; recreational forests; biomass; mortality
Available at various institutes of the ASCR
USE OF NORWAY SPRUCE AS ADMIXTURE IN SUBURBAN FORESTS AT LOWER ALTITUDES
In suburban forestry there is a need not only to manage a maximum financial result, but also to support recreational and aesthetic forest functions. Thus, these forests need professional treatments in ...
Statistical analyses of Land Surface Temperature in Local Climate Zones: Case study of Brno and Prague (Czech Republic)
Geletič, Jan; Dobrovolný, Petr; Lehnert, M.
2017 - English
The classification of "local climate zones" (LCZs) emerged in urban climatology to standardize description of urban climate research sites. One of the goals of classification was to get beyond urban-rural dichotomy which enabled to study urban air temperature field in more detail. Based on empirical and modelling work LCZ have proven effective in examining intra-urban air temperature differences, however a robust examination of intra-urban land surface temperatures using the LCZ framework remains elusive. In this study a GIS-based method is used for LCZ delimitation in Prague and Brno (Czech Republic), while land surface temperatures (LSTs) derived from LANDSAT and ASTER satellite data are employed for exploring the extent to which LCZ classes discriminate with respect to LSTs. Results indicate that LCZs demonstrate the features typical of LST variability, and thus typical surface temperatures differ significantly among most LCZs. ANOVA and subsequent multiple comparison tests demonstrated that significant temperature differences between the various LCZs prevail in both cities (89.3% and 91.6% significant LST differences for Brno and Prague respectively). In general, LCZ 8 (large low-rise buildings), LCZ 10 (heavy industry) and LCZ D (low plants) are well-distinguishable, while LCZ 2 (compact midrise), LCZ 4 (open high-rise), and LCZ 9 (sparsely built-up) are less distinguishable in terms of their LST. In most of the scenes LCZ 10 (heavy industry), LCZ 2 (mid-rise buildings) and LCZ 3 (low-rise building) are the warmest and LCZ G (water bodies) and LCZ A (dense forest) are the coolest zones in term of their LST. Further studies are needed to account for observational errors (such as seasons differences or thermal anisotropy) on LCZ LST patterns.
Keywords:
Land Surface Temperature; Local Climate Zones; aster; landsat; Analysis of variance
Available at various institutes of the ASCR
Statistical analyses of Land Surface Temperature in Local Climate Zones: Case study of Brno and Prague (Czech Republic)
The classification of "local climate zones" (LCZs) emerged in urban climatology to standardize description of urban climate research sites. One of the goals of classification was to get beyond ...
Využití dat z ceilometru při intepretaci vývoje koncentrací látek v ovzduší během dne
Komínková, Kateřina; Holoubek, Ivan
2017 - Czech
Pro interpretaci naměřených koncentrací látek znečišťujících atmosféru je jedním z klíčových parametrů výška mezní vrstvy atmosféry a její vývoj během dne. Planetární mezní vrstva (angl. Planetary Boundary Layer - PBL) atmosféry je široký pojem, který v sobě zahrnuje různé stavy dynamiky proudění vzduchu v části troposféry nejblíže při zemském povrchu (0 – 2 km nad povrchem), jehož bezprostřední vliv se v této oblasti projevuje. Během dne dochází v PBL ke změnám proudění. Pro měření koncentrací látek v ovzduší je velmi podstatný především vývoj (konvektivní) směšovací vrstvy (angl. Mixing Layer - ML) ve světelné části dne. Existuje řada nepřímých technik umožňujících stanovení vývoje výšky PBL, jednou z metod ednoduchou na provoz je stanovení výšky PBL na základě dat z ceilometru. Získaná data jsou ale poměrně náročná pro interpretaci. Při měření v terénu navíc nastává poměrně hodně případů, kdy hodnoty výšky PBL není možné neboť měření ceilometrem je rušeno. For the interpretation of air pollutants concentrations, the one of the key parameter is the atmospheric boundary layer (ABL) evolution during a day and night. The ABL is a broad concept that includes different states of airflow dynamics in the part of troposphere closest to the Earth's surface (0-2 km above the surface), which has an effect in this area. A lot of air flow changes occur in the ABL during the day. For the measurement of substances concentrations in the air the development of mixing layer (ML) in the light part of the day is very important. A lot of ground remote sensing methods was developed for determination of ABL height during the day, one of them which can be very simply operated is to use data from ceilometer. However, the obtained outputs cannot be directly interpreted. In addition, in the case of the terrain measurements a lot of cases when ABL height values cannot be determined because the ceilometer measurement is disturbed can occur.\n\n
Keywords:
ceilometr; atmospheric boundary layer; mixing layer height concentration gradient; tropospheric ozone
Available at various institutes of the ASCR
Využití dat z ceilometru při intepretaci vývoje koncentrací látek v ovzduší během dne
Pro interpretaci naměřených koncentrací látek znečišťujících atmosféru je jedním z klíčových parametrů výška mezní vrstvy atmosféry a její vývoj během dne. Planetární mezní vrstva (angl. Planetary ...
Modulation of ozone flux in a mountain spruce forest under different cloud cover
Juráň, Stanislav; Fares, S.; Urban, Otmar
2017 - English
Ozone (O3) fluxes were modelled from a concentration gradient in a Norway spruce forest at the Bílý Kříž experimental station for years 2012–2016. Daily and seasonal O3 depositions were calculated separately for days with cloudy, partly cloudy, and clear sky conditions. The hypothesis that overcast conditions modulate O3 flux in the forest ecosystem via controlled stomatal conductance is tested. Indeed, the highest stomatal conductance followed by the highest O3 deposition was found during partly cloudy and cloudy sky conditions in all seasons.
Keywords:
ozone; norway spruce; sky conditions; inverse lagrangian transport model
Available at various institutes of the ASCR
Modulation of ozone flux in a mountain spruce forest under different cloud cover
Ozone (O3) fluxes were modelled from a concentration gradient in a Norway spruce forest at the Bílý Kříž experimental station for years 2012–2016. Daily and seasonal O3 depositions were calculated ...
Influence of the chlorophylls-to-carotenoids ratio on light use efficiency estimation by optical parameters
Ač, Alexander; Kováč, Daniel; Veselovská, Petra; Večeřová, Kristýna; Klem, Karel
2017 - English
The influence is examined of changing leaf photosynthetic pigments concentrations on sensitivity of the\nphotochemical reflectance index (PRI) and ΔPRI optical parameters in relation to light use efficiency\n(LUE). Photosynthetic and leaf chlorophylls-to-carotenoids (Chl/Car) ratio changes during the growth of\nEuropean Beech (Fagus sylvatica) and Norway spruce (Picea abies) saplings were induced by altering the\nliving environment inside growth chambers. Point reflectance measurements of each individual tree were\nrecording changes in optical properties while measurements were being taken simultaneously of altering\nphotosynthesis. Based on the evaluation of 45 pairs of measurements conducted on six individual saplings,\nthe observed variability in the strength of the PRI and ΔPRI versus LUE relationships was compared to the\nresulting leaf Chl/Car ratio of each tree. Data were used to explain the influence of changing pigments on\nthe sensitivity of each individual optical parameter with regards to the LUE estimation.
Keywords:
chlorophylls carotenoids; light use efficiency; optical parameters
Available at various institutes of the ASCR
Influence of the chlorophylls-to-carotenoids ratio on light use efficiency estimation by optical parameters
The influence is examined of changing leaf photosynthetic pigments concentrations on sensitivity of the\nphotochemical reflectance index (PRI) and ΔPRI optical parameters in relation to light use ...
Carbon-smart forestry for building resilience to global change
Brnkalakova, S.; Kluvánková, T.; Marek, Michal V.
2017 - English
The specific role of mountain ecosystems in the carbon cycle and their importance as carbon sinks already\nhas been noted within the broader debate about climate change. There has been progress in designing\nand attempts towards implementing such mountain-specific strategies as green economies, global and regional\nconventions, frameworks, and institutions. There is still need, however, for new and integrative approaches\nto governing mountains in a sustainable and adaptive way with local and global contributions.\nThe proper institutional arrangement, adaptive forest management, and sustainable use of forest ecosystems\ncan make a substantial contribution to the well-being of local communities as well as contribute to\nmitigating global climate change by provisioning of carbon sequestration ecosystem service. This paper\nexamines how reconfiguration of social practice in forest-dependent communities can address urgent societal\nchallenges. In particular, it considers the potential of a common pool resource regime for governance\nand carbon-smart forestry in innovative management of mountain ecosystems to meet societal and natural\nchallenges.
Keywords:
mountain ecosystem; carbon cycle; carbon forestry
Available at various institutes of the ASCR
Carbon-smart forestry for building resilience to global change
The specific role of mountain ecosystems in the carbon cycle and their importance as carbon sinks already\nhas been noted within the broader debate about climate change. There has been progress in ...
Urban ecosystem services in climate change mitigation
Štecová, I.; Kluvánková, T.; Pavelka, Marian
2017 - English
Climate change and global warming rapidly affect urban residents’ well-being. More than 72% of Europeans\nlive in urban environments, and their well-being is closely related to environmental quality. How cities are\nplanned and structured can exacerbate the negative effects of climate change even as natural elements and\ngreen areas are shrinking. The impact of high temperature on human health during heat waves will be one of\nthe most serious problems associated with climate change, and especially in large urban areas. Heat islands\nare mainly due to high concentration and large areas of impermeable surfaces, low moisture, few green areas,\nand poor ventilation. We present results from measuring heat islands at two locations in Bratislava and interview\nkey actors from three cities to identify risk perception regarding climate change. Expected results aim\nto mainstream ecosystem services into spatial planning in cities in support of operationalizing microclimatic\nfunction of green infrastructure to mitigate negative impact of climate change in cities.
Keywords:
global warming; ecosystem services; climate change mitigation
Available at various institutes of the ASCR
Urban ecosystem services in climate change mitigation
Climate change and global warming rapidly affect urban residents’ well-being. More than 72% of Europeans\nlive in urban environments, and their well-being is closely related to environmental quality. ...
Ecosystem services in environmental policy and decision-making in the Czech Republic
Daněk, Jan
2017 - English
In response to the increasing popularity of the ecosystem services concept among scholars and policy makers\non the international level, it has become time to analyse the current state and possibilities for national\npolicy and decision-making in reflecting this concept. This article presents a sneak preview of research\nfocused on content analysis of environmental policy documents. Two current and one outdated climate\nchange policy document are analysed regarding notions of the ecosystem services concept and other aspects\nof an ecosystem-based approach. The output data show contrasting results, with the Adaptation\nStrategy scoring very high compared to the Climate Protection Policy, which almost does not reflect the\necosystem services or related ecosystem approach. Implications of the results and the entire context of the\nresearch are discussed in respective sections.
Keywords:
ecosystem services; environmental policy; decision making; Czech Republic
Available at various institutes of the ASCR
Ecosystem services in environmental policy and decision-making in the Czech Republic
In response to the increasing popularity of the ecosystem services concept among scholars and policy makers\non the international level, it has become time to analyse the current state and ...
Využití odběrových filtrů z atmosférické stanice Křešín pro další analýzu
Vítková, Gabriela; Kahoun, D.; Strnadová, G.; Hanuš, Vlastimil; Petrov, M.; Tříska, Jan; Holoubek, Ivan
2017 - Czech
Atmosférická stanice Křešín u Pacova slouží jako monitorovací bod výskytu a dálkového přenosu skleníkových plynů, vybraných atmosférických polutantů a základních meteorologických charakteristik. Stanovení koncentrace skleníkových plynů (CO2, CH4, N2O, CO) se provádí ve vzduchu kontinuálně vzorkovaném ve výškách 10, 50, 125 a 250 m. Samotná analýza probíhá u paty vysokého stožáru, kam je vzduch veden pomocí trubic z materiálu Synflex 1300. Vzorkovací linky a jednotlivé analyzátory jsou před mechanickým znečištěním chráněny vstupními filtry, které jsou měněny v pravidelných intervalech v rámci rutinní údržby zařízení, nebo dříve, dojde-li k jejich neočekávanému ucpání. Analýza těchto filtrů může poskytnout další informace o prostředí v okolí stanice. Jedná se o nerezové filtry (Swagelog „T“ filtr) s porozitou 40 μm. Před nimi je předsazena odběrová hlava sloužící k ochraně před hrubými nečistotami a kapkami vody. Objemový průtok prosávaného vzduchu činí cca 15 l/min, interval výměny je obvykle 3 měsíce. Potřeba výměny těchto filtrů se v posledních měsících zvýšila, neboť průtok na vzorkovacích linkách poklesl. Vyvstává otázka, jak dlouho filtry zůstávají plně průchozí a jak dobře slouží svému účelu, aniž by zatěžovaly vzorkovací systém a snižovaly kvalitu měření. K odpovědi na tuto otázku by mohly být nápomocny výsledky analýz polycyklických aromatických uhlovodíků (PAHs) prováděné na filtrech na Ústavu chemie a biochemie Přírodovědecké fakulty Jihočeské Univerzity a také snímky ze skenovacího elektronového mikroskopu (SEM). Na základě předběžných výsledků zde navrhujeme rozsáhlejší studii pro využití tohoto odpadního materiálu k analýze pevných částic z ovzduší v okolí AS Křešín u Pacova a optimalizaci postupů QA/QC vzorkovacího systému analyzátorů skleníkových plynů. The Kresin At Pacov Atmospheric Station serves as a monitoring point for the occurrence and remote transmission of greenhouse gases, selected atmospheric pollutants and basic meteorological characteristics. The determination of the GHG concentration (CO2, CH4, N2O, CO) is carried out in air continuously sampled at 10, 50, 125 and 250 m heights. The analysis itself takes place at the foot of a high mast where the air is drawn through the tubes of Synflex 1300. lines and individual analyzers are protected from mechanical pollution by input filters that are changed at regular intervals as part of the routine maintenance of the device or earlier when unexpected clogging occurs. Analyzing these filters can provide additional information about the surrounding area. These are stainless filters (Swagelog „T“ filter) with a porosity of 40 μm. A sampling head is provided in front of them to protect them from rough dirt and water drops. The volume flow of the scrubbed air is about 15 l / min, the exchange interval is usually 3 months. The need to replace these filters has increased in recent months as the flow rate on the sampling lines has fallen. The question arises as to how long the filters remain fully passable and how well they serve their purpose without burdening the sampling system and lowering the measurement quality. The results of analyzes of polycyclic aromatic hydrocarbons (PAHs) carried out on filters at the Institute of Chemistry and Biochemistry of the Faculty of Science of South Bohemian University as well as images from the Scanning Electron Microscope (SEM) could be helpful in answering this question. On the basis of the preliminary results, we propose a more extensive study for the use of this waste material for the analysis of solid particles from the atmosphere in the surroundings of AS Křešín near Pacov and the optimization of the QA / QC sampling systems of greenhouse gas analyzers.
Keywords:
filters; greenhouse gases; polycyclic aromatic hydrocarbons; scanning electron microscope
Available at various institutes of the ASCR
Využití odběrových filtrů z atmosférické stanice Křešín pro další analýzu
Atmosférická stanice Křešín u Pacova slouží jako monitorovací bod výskytu a dálkového přenosu skleníkových plynů, vybraných atmosférických polutantů a základních meteorologických charakteristik. ...
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