hrvatski

Raspodjela izotopnog sastava vodika, kisika i ugljika u atmosferi Hrvatske i Slovenije

Natural cycles of water and carbon can be studied by monitoring the isotopic composition of H2O and CO2 in the atmosphere. The monitoring includes isotopes 2H, 3H and 18O in precipitation, and 13C and 14C in atmospheric CO2. The results of such a monitoring of the atmosphere over Croatia and Slovenia during last several years are presented here. Monthly precipitation samples at Zagreb and Ljubljana have been collected since 1976 and 1981, respectively. In the period 2000-2003 the sampling network has been extended to 7 stations along the Adriatic coast of the two countries. Tritium activity in precipitation shows seasonal variations that are most pronounced at the continental stations (Zagreb, Ljubljana) followed by the north-Adriatic (Portorož, Kozina, Malinska) and mid-Adriatic stations (Zadar, Zavižan), and the smallest are at the south-Adriatic stations (Komiža, Dubrovnik). The mean annual tritium activity also decreases from the north to the south of the Adriatic coast. Seasonal variations in  2H and  18O in precipitation follow the temperature variations at the sampling station, and the mean annual  18O values follow the mean annual temperatures. Thus, the south-Adriatic stations show the smallest variations in  18O and highest mean  18O values. Atmospheric CO2 has been collected on a monthly basis in Zagreb and Plitvice. Seasonal variations in both  14C and  13C have been observed. The mean annual 14C activities in Zagreb were decreasing after the maximum in 1960-ties and approached the natural pre-bomb activities. During the last 3 years the mean 14C activity  14C remains about 30‰ . This study extended our knowledge about natural spatial and temporal distributions of 2H, 3H, 13C, 14C and 18O in the atmosphere over a relatively small area reach in diversity of climatic and geographic characteristics.

tricij; stabilni izotopi 18O i 2H; oborine; atmosfera

Rad (bez sazetka) na hrvatskom jeziku, extended abstract na engleskom.