The physical state of the atmosphere finds itself in continuous change. As such, it can be characterized as generating complex physical processes and out of these physical processes, a significant impact upon agriculture is imposed by severe weather events. All the heights that characterize the state of the atmosphere and of the oceans do possess a significant spatial but also temporal variability. At synoptic level, the atmospheric blocking circulation is determined by the persistence of very strong anticyclonic circulation, which extends on the entire tropospheric column. As such, the reorientation of the jet stream from its normal quasi-zonal circulation towards a polar direction is, as such, due to the jet stream’s barotropic structure. The main aim of this paper is to analyse and present a short climatology of the blocking circulation events in the time scale 2000-2005 and their influence on agriculture. Throughout this paper the main meteorological parameter which will be analysed is the geopotential surface at non divergent level (500 hPa). The atmospheric blocking circulation is at best detected in the upper surface of the atmosphere. As such the presence of a blocking circulation above a region is equivalent to the existence of a large area of high pressure, which is characterized as being slow compared to a low-pressure area. The mean latitude region is characterized as having westerly winds at the surface as well as in altitude. The study concludes that the appearance and the persistence of the atmospheric blocking circulation events may, in some extent explain, the persistent drought especially in Câmpia Română. Besides this, another important blocking circulation event, which occurred in March 2005, led to severe flooding in the western part of Romania.

blocking circulation, agriculture, geopotential height, drought, flooding

environmental engineering

Presentation: None