67 research outputs found

    Trends in the characteristics of allergenic pollen in Szeged, Hungary

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    The aim of the study is to analyse trends of the pollination season with its start and end dates, as well as trends of annual total pollen count and annual peak pollen concentration for Szeged, Hungary. The data set covers an 11-year period (1999-2007) and includes one of the largest spectra, with 19 taxa, as well as five meteorological variables. After performing Mann-Kendall tests, the annual cycles of slopes of daily pollen concentration trends and annual cycles of slopes of daily climate variable trends are calculated. Representing the strength of their relationship an association measure was introduced. Total annual pollen count calculated by linear trends and annual peak pollen concentrations indicate a small number of trends, while total annual pollen count calculated by daily linear trends show significant trends (71% of them positive) for almost all taxa. However, phenological characteristics are free of significant changes except for Urtica. We received that the association measure performs well when comparing it to the climate change related forces. Furthermore, significant changes in pollen characteristics are also in accordance with the risk and expansion potential due to the climate change

    Long-range transport of PM10 : Part 2.

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    The purpose of this study is to identify long-range transport patterns that may have an important influence on PM10 levels in four European cities at different latitudes, namely those in Thessaloniki, Szeged, Helsinki and Oulu. Trajectory positions were computed using the HYSPLIT model. 4-day, 6-hourly 3D backward trajectory positions arriving at these locations at 1200 GMT were determined for each day over a 5-year period from 2001 to 2005. Non-hierarchical cluster analysis with the k-means method was applied using a Mahalanobis metric. The efficiency of the 2D and 3D cluster analyses were compared for each city

    Körkörös adatok statisztikai elemzése és meteorológiai alkalmazása = Statistical analysis of circular data and its application in meteorology

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    Kidolgoztunk és alkalmaztunk egy eljárást a turbulens áramok kiszámításához szükséges lokális átlagok és fluktuációk képzéséhez szükséges lokális sávszélesség becslésére. Fontos, hogy az eljárás a korábbiakkal ellentétben nem él az adatsorban jelenlévő trendre vonatkozó szigorú feltevéssel (nincs trend, lineáris a trend). A sávszélességet úgy határoztuk meg, hogy a nyers áramok becslésének szisztematikus hibája minimális legyen. Vizsgáltuk az átlagos áramok kiszámításának időbeli felbontását is. Azt találtuk, hogy az áramokat csak legalább 30 perces hosszúságú időszakokra lehet kellő pontossággal megadni. A hegyhátsáli TV torony 113 m-es szintjén mért szén-dioxid (CO2) koncentráció és az ide befutó, a nagytérségű cirkulációt jellemző 5 napos backward trajektóriák kapcsolatát elemeztük. A CO2 koncentráció és a trajektóriák menti információ (pl. a keveredési rétegvastagság) közötti kapcsolat nem túl erős. A kapcsolat hónapról hónapra változik, világos évi menet nélkül. A trajektóriák típusokba sorolása azt mutatja, hogy a trajektória típusok jól érzékelhető de nem alapvető szerepet játszanak a CO2 koncentráció alakulásában. A CO2 koncentráció változásait regionális folyamatok határozzák meg. | A methodology to estimate variable bandwidths to form local means and fluctuations in turbulent data sets has been developed and applied to real data. The method, in contrast with other previous techniques, can produce rough turbulent fluxes without any strong assumption on trends such as lack of trends or linear trends. Bandwidth is chosen such that after removing the estimated trend from data the estimate of rough fluxes has as small bias as possible. Time resolution for calculating average fluxes has also been examined. It was found that averaging lengths not shorter than 30 minutes are necessary to calculate average fluxes. Relationship between local atmospheric carbon-dioxide (CO2) concentration measured at a 113 m height on a tower in Hegyhatsal, Hungary and five-day backward trajectories reflecting large-scale transport processes has been examined. Relationship between CO2 concentrations and information along trajectories (e.g. mixing layer height) is not too strong. Also, the relationship varies among months without a clear annual cycle. Classification of trajectories into types shows that trajectories have apparent but not substantial role in formation of CO2 concentrations. Variations of CO2 concentration are governed by regional scale processes

    The origin and worldwide distribution of regweed- a review

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    The aim of the study is to provide a survey on the history of ragweed worldwide. Its climate dependence, impacts in agriculture, health effects and social costs are also presented. In Europe common ragweed (Ambrosia artemisiifolia) is predominant of all Ambrosia species that is supported by population genetic data. The most important habitat areas of ragweed and the highest pollen concentrations occur, in decreasing order of the pollen levels (1) in the south-western part of the European Russia, (2) in the southern and eastern parts of Ukraine, (3) in the Pannonian Plain in Central Europe, (4) in the RhĂ´ne-Alpes region in France, furthermore (5) in the Po River valley in Italy. Besides Europe, ragweed occurs in China, India, Japan and in other Asian countries, furthermore in Australia and the Unites States of America. However, beyond the USA little information is available. Warming trends due to the climate change favours the expansion of ragweed, producing higher pollen levels worldwide. In association with the warming, increasing ambient CO2 levels generate greater biomass and increased pollen production. Hence, ragweed pollen production can be expected to increase significantly under predicted future climate conditions, bringing severe impacts to areas that have yet been suffering slightly

    Időjárási szélsőségek matematikai statisztikai vizsgálata változó éghajlati feltételek mellett = Mathematical statistical analysis of extreme weather events under changing climate

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    A pályázati munka keretében változó éghajlati feltételek mellett vizsgáltuk az időjárási szélsőségeket. Elméleti, módszertani és modellezési feladatokkal, valamint konkrét elemzésekkel és az abból levonható következtetésekkel foglalkoztunk. Az eredmények jelentős része publikálásra került. A zárójelentésben a legfontosabb eredmények bemutatására kerül sor: a beszámoló részben a sokrétű kutatás egységes tárgyalását tartalmazza, részben pedig az egyes területeken elért eredmények összefoglalóit. | During the project we have been examining the extreme weather parametres under changing climate conditions. We have been dealing with theoretical, methodological and modelling tasks, and also with given analysis on the basis of local meteorological time series and conclusions deducted from these results. Most of the results have been published. In the final report the most important results are being introduced: the report partly comprises the certain fields of research and partly the summary of the results reached and achieved

    The origin and worldwide distribution of regweed

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    The aim of the study is to provide a survey on the history of ragweed worldwide. Its climate dependence, impacts in agriculture, health effects and social costs are also presented. In Europe common ragweed (Ambrosia artemisiifolia) is predominant of all Ambrosia species that is supported by population genetic data. The most important habitat areas of ragweed and the highest pollen concentrations occur, in decreasing order of the pollen levels (1) in the south-western part of the European Russia, (2) in the southern and eastern parts of Ukraine, (3) in the Pannonian Plain in Central Europe, (4) in the RhĂ´ne-Alpes region in France, furthermore (5) in the Po River valley in Italy. Besides Europe, ragweed occurs in China, India, Japan and in other Asian countries, furthermore in Australia and the Unites States of America. However, beyond the USA little information is available. Warming trends due to the climate change favours the expansion of ragweed, producing higher pollen levels worldwide. In association with the warming, increasing ambient CO2 levels generate greater biomass and increased pollen production. Hence, ragweed pollen production can be expected to increase significantly under predicted future climate conditions, bringing severe impacts to areas that have yet been suffering slightly
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