Empirical downscaling method as a tool for development of regional climate change scenario | Nekatere metode za pripravo regionalnih scenarijev podnebnih sprememb

anglais. Results of simulations with general circulation models (GCM) are the basis for the future climate change and impact studies. In our case, results of simulations with four GCM (CSIRO/Mk2, UKMO/HadCM3, DOE-NCAR/PCM and MPI-DMI/ECHAM4-OPYC3), based on SRES A2 and B2 marker emission scenarios, were used. The mean monthly values of near ground air temperature and sea level pressure were selected for the period 1951-2100 and used as predictor values. The results of GCM were projected to near ground air temperature and precipitation amount at five locations in Slovenia (Ljubljana, Novo mesto, Murska Sobota, Rateče, and Bilje) by using empirical downscaling. Different regression techniques were used for the development of empirical downscaling models (EM) that relate selected large-scale predictors with local-scale predictands. The EM were developed by means of data from ARSO archive and NCEP/NCAR reanalysis data for the period 1951-2002. Derived EM explained a great part of variability of local air temperature at all five locations. This was not the case for the local precipitation, where the quality of EM is acceptable only for the months of the cold half of the year. Local projections of GCM results by EM were additionally scaled to other (A1Fl, A1B, A1T, and B1) marker SRES scenarios and used as a base for the development of regional climate change scenarios.

slovène. Za oblikovanje strategij prilagoditev predvidenim podnebnim spremembam potrebujemo scenarije bodočega podnebja v regionalni skali. Lokalne podnebne razmere so običajno v veliki meri odvisne od procesov, ki potekajo v manjši skali, kot je prostorska ločljivost globalnih modelov splošne cirkulacije (MSC), ki so orodje za proučevanje odziva podnebnega sistema na spremembe sestave ozračja. V delu so zato prikazani načini, kako premostimo prepad med obsežno prostorsko in regionalno skalo, kar imenujemo tudi empirično zmanjševanje skale. Pri tem smo za povezavo podnebnih spremenljivk v regionalni oziroma lokalni skali s podnebnimi spremenljivkami v obsežni skali uporabili različne matematične modele. Modele, ki temeljijo na izmerjenih vrednostih v preteklosti, smo uporabili za projeciranje rezultatov simulacij štirih MSC. Pri tem predpostavimo, da bo v spremenjenih podnebnih razmerah matematični opis odvisnosti med lokalno podnebno spremenljivko in podnebno spremenljivko v globalni skali še vedno veljaven. V obdobju 2001 do 2030 se bodo v Sloveniji temperature zraka povečale za 0.5°C do 2.5°C, v obdobju 2031 do 2060 za 1°C do 3.5°C in v obdobju 2061 do 2090 za 1.5°C do 6,5°C. Več težav je z empiričnimi modeli za ocenjevanje letne količine padavin, saj je kakovost modelov zadovoljiva le za mesece hladne polovice leta.