95 research outputs found
A városi hĹ‘sziget problĂ©ma Ăşj mĂłdszertani közelĂtĂ©sei
Mára már a Föld lakosságának több mint fele nagyvárosokban Ă©l, Ăgy egyre nagyobb az igĂ©ny, hogy megmĂ©rjĂĽk, felmĂ©rjĂĽk, modellezzĂĽk, elĹ‘rejelezzĂĽk a városok mĂłdosult Ă©ghajlati sajátosságait, s hogy ezek negatĂv következmĂ©nyeit már az Ă©pĂĽletek, gyárak tervezĂ©si, telepĂtĂ©si fázisában kiszűrhessĂĽk, minimalizálhassuk. Kutatásaink során finom felbontásĂş műholdas adatokat használtunk, digitális magassági modellt, digitális felszĂnborĂtottsági/felhasználati adatbázist. A kutatási projekt során elvĂ©gzett elemzĂ©sek, s azok eredmĂ©nyei: (1) FinomfelbontásĂş műholdas felvĂ©telek felhasználásával megtörtĂ©nt a városi hĹ‘sziget struktĂşra elemzĂ©se Magyarország, illetve KözĂ©p-EurĂłpa nĂ©hány nagyobb városára. Vizsgálatainkhoz a felszĂni hĹ‘mĂ©rsĂ©klet-mezĹ‘sorokat az amerikai Terra Ă©s Aqua műhold MODIS szenzorának 1 km-es tĂ©rbeli felbontásĂş mĂ©rĂ©seibĹ‘l vettĂĽk. (2) A hĹ‘sziget-hatás szerkezetĂ©nek Ă©rtĂ©kelĂ©sĂ©t elvĂ©geztĂĽk az Ă©vszakok, a domborzat Ă©s a felszĂntĂpus fĂĽggvĂ©nyĂ©ben a fĹ‘városra, illetve a hazai nagyvárosokra. (3) ElvĂ©geztĂĽk a NOAA-műholdak AVHRR-szenzoraival mĂ©rt felszĂni hĹ‘mĂ©rsĂ©klet-meghatározĂł algoritmusok összehasonlĂtĂł elemzĂ©sĂ©t. (4) ElemeztĂĽk a felszĂnborĂtottság Ă©vtizedes skálájĂş változásai nyomán lĂ©trejövĹ‘ hatásokat. (5) Az NDVI mezĹ‘k idĹ‘sorainak tendencia-elemzĂ©se megtörtĂ©nt a NOAA-műholdkĂ©pek alapján, s matematikai statisztikai eljárások felhasználásával összehasonlĂtottuk a városi Ă©s az azokat körĂĽlvevĹ‘ vidĂ©ki rĂ©giĂłkat. | More than half of the world population are living in large urban agglomerations. Therefore, an increasing demand appeared for measuring, modelling and forecasting the urban climate, and minimalize or even possibly avoid the negative effects of the urban environment in the planning and building phases of new industrial investments or construction of new residential areas. In our research fine resolution satellite data sets are used, as well, as data sets from digital elevation models and land use/land cover characteristics. The following tasks have been accomplished. (1) Analyses of the structure of urban heat island (UHI) effect in several cities of Hungary and Central Europe on the base of fine resolution satellite images of sensor MODIS on-board satellites Terra and Aqua (with 1 km spatial resolution). (2) Evaluation of UHI structure of Budapest and other 9 Hungarian large cities depending on seasons, topography, and land cover. (3) Comparison of algorithms for determining surface temperature based on NOAA/AVHRR measurements. (4) Tendency analysis of decadal land cover change in the Carpathian basin. (5) Tendency analysis of NDVI fields on the base of NOAA/AVHRR data, and comparison of urban and rural regions using mathematical statistical methods
Regional effects of ENSO in Central/Eastern Europe
El Niño - Southern Oscillation (ENSO) effects on the European circulation features and on the regional climate of Hungary are evaluated in this paper. European climate is represented by atmospheric macrocirculation patterns (MCPs). Local climate characteristics are linked to ENSO phases through regionally averaged temperature values and precipitation amounts. Significant statistical relationship was found between the European circulation and the ENSO phases. Furthermore, considerable differences were detected in the empirical frequency distribution of monthly climate anomalies in Hungary during El Niño and La Niña episodes
Comparison of Simulated Trends of Regional Climate Change in the Carpathian Basin for the 21st Century Using Three Different Emission Scenarios.
The present paper discusses the regional climate mo
deling experiments for the 21st
century for the Carpathian Basin using the model PR
ECIS. The model PRECIS is a hydrostatic
regional climate model with 25 km horizontal resolu
tion developed at the UK Met Office, Hadley
Centre. Simulated future changes – in mean climatic
values, distributions and empirical
probabilities – are analyzed for the period 2071–21
00 (compared to 1961–1990, as a reference
period). Significant warming is projected at 0.05 l
evel for all of the A2, A1B, and B2 scenarios,
the largest warming is estimated in summer. Not onl
y the mean value is likely to change, but also
the distribution of daily mean temperature. By the
end of the century the annual precipitation in
the Carpathian Basin is likely to decrease, and the
annual distribution of monthly mean
precipitation is expected to change. Significant dr
ying is projected in the region in summer, while
in winter the precipitation is estimated to increas
e
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