COLD WAVES IN THE ROMANIAN CARPATHIANS, AN INDICATOR OF NEGATIVE TEMPERATURE EXTREMES
D. MICU
ABSTRACT. – Cold waves in the Romanian Carpathians, an indicator of negative temperature extremes. Cold waves are a representative indicator frequently used to analyze the incidence of cold extremes in a given area. This study was undertaken on these cold extremes in the Romanian Carpathians defined by the STARDEX project. Investigations had in view mountain weather stations located >1,000 m a.s.l. (15 sites) over the 1961-2003 period of available daily temperature records. Long-term records of daily minimum temperature (blended) were also studied from the available ECA&D data sets at Omu Peak station (1928-2011). Regional patterns of cold waves were expressed by comparing their frequency, duration and intensity at the weather stations located in the alpine, sub-alpine and forest vegetation belts. There is an evident inter-annual variability of cold wave duration, showing a significant increase particularly in some forest belt locations in the Southern Carpathians. However, the long-term variability trend (83 years) at Omu Peak alpine station showed quite an opposite trend, corresponding to the warming process in terms of minimum temperature values. Cold waves are usually associated to a high number of consecutive frosty nights and freeze days, but they have low effects on the characteristics of snow season.
Keywords: cold extremes, cold wave duration index, variability, mountain region.