DISTRIBUTION OF CLOUDINESS ON THE CENTRAL PLATEAU OF MOLDAVIA

Abstract

The distribution of cloudiness on the Central Plateau of Moldavia is almost similar with that of other hilly areas of Romania, although the mentioned area are located in the east of Romania, where continental influences are present. In the Central Moldovan Plateau. The values of the cloudiness are higher than in the south-eastern areas of Romania, due to specific conditions. In winter the values are raised by the lower temperatures, sometimes generated by the presence of the Euro-Asian Anticyclone and by the high frequency of the thermal inversions. In addition, there is an intensification of the passages of Mediterranean cyclones, often above the anticyclonic cold air. At the end of spring and in the first half of summer, the western circulation intensifies, to the north of the Carpathians, as it enters the studied area. The Central Plateau of Moldavia is a relatively high area, located in the front of the predominant north-western local circulation, a fact that produces slight orographic convection in the case of north component circulations. The annual average of cloudiness is heavily influenced by the genesis of stratiform clouds. The multiannual regime shows decreases of the values. The annual regime is similar for entire Central Plateau of Moldova. In the Central Plateau of Moldavia, both the total and low cloudiness recorded has the highest average in December and the lowest average in August. Total hourly cloudiness recorded two main classes of values between 4-6, with presence in the months of warm semester and 6-8 tenths, characteristic of the cold semester. The low cloudiness presents, in the territory, small differencies for the annual averages and higher differencies than the total cloudiness regime. Diurnal, the low cloudiness exceeds 6 tenths only in the mornings of December, in Vaslui and values below 2 tenths occur only on the nights of June, July, August and September in whole area. The values in the territory are similar, only in the high areas we can see a slight increase in the number of clear sky days, with a corresponding decrease in the number of cloudy and covered days.