Study of mixing layer height in Mehrabad airport,Case Study: Period 2017-1998

In this study we obtained the maximum height of the mixed layer for each day in the time period 1998 to 2017 by using the radiosonde zero Greenwich data of Mehrabad airport station in Tehran and also using the maximum temperature measured at 12 GMT at the same station. The mean value of the depth of the mixed layer whit monthly time separation during the studied time period as well as the maximum, minimum and average height of the mixed layer for January, December, July and August were calculated as the representative of the two cold and two warm months. In the following the selected samples were analyzed by the SKEW-T chart. The results showed that the average maximum height of the mixed layer in warm seasons was between 3 to 4 km and in cold seasons between 1 and 2.5 km. The purpose of this research is to provide a method that predicts the depth of the mixed layer by using the upper air data of the zero GTM and also using the predicted maximum temperature. The predicted results can be used in suitable time range for practical, scientific and prognosis purposes.