The Study of Condition and the Intensity of Lower Level Temperature Inversion in Tabriz of 2004-2008

In this research we have studied Tabriz temperature inversion using radio-sound information، during the 2004-2008 periods in daily، monthly and seasonally scales. Produced data associated with temperature inversion daily of the surface (2 meters) to 700 H. Pa. Several different measures are used، including the height of the base and the height of the top of the inversion، the temperature at the base and at the top of the inversion، the temperature difference across the inversion، the depth of the inversion and pressure of base and top temperature inversion layer. After reviewing the information and data at first days with weak، medium، and intense and very intense temperature inversion conditions were specified. The results indicate that mean annual temperature inversion phenomenon in Tabriz is equal to 191 days، 87% of which is related to the radiation temperature inversion and the remaining 13% is related to the subsidence temperature inversion. In total، 24 days intensity temperature inversion have seen which occurred 17 in winter particularly 12 days during the month of January and 7 days in autumn season. Very intense inversions occasions have mostly occurred during the cold season are radiation temperature inversion. In addition to 70% two stage temperature inversions occurred in winter season particularly in the month of January. Findings of this research have shown that restless to thickness inversion layer، peaked intense temperature inversion when hence difference temperature layer.