دراسة ساينوبتيكية للامطار في العراق باستخدام بيانات الاقمار الاصطناعية

Rain is the one of most important meteorological parameter and the most parameter that varies in space and time. Because of the climate change of the Earth that occurred particularly during the second half of the past century, the precipitation patterns has been change and many areas has been suffering from water recourses shortage, and many of these areas droughted and became desert. For these reasons, there has been an increasing interests in the climate researches, especially those concerning rain. In addition, the industrial developments lead to more sophisticates measuring instruments and today it is possible measure rainfall rate with radars and satellites. The aim of this research is study the synoptic situation of rainfall over Iraq using satellite data. To carry out this research, rainfall and meteorological parameters extracted from satellite images provided by the National Center for Environmental Prediction (NCEP) for the period 1998 – 2008 were used. To verify the NCEP rainfall data, they were compared with corresponding data recorded by the Iraqi Meteorological Organization (IMO) and by the National Aeronautic and Space Agency (NASA). The results indicated that the values of rainfall from the three sources were very closes with a correlation coefficients of 0.971 between IMO and NCEP data, 0.961 between IMO and NASA, and 0.966 between NCEP and NASA. Results of data analysis showed that the low pressure systems over Iraq were characterized by an atmospheric pressure of 800 to 840 mb, relative vorticity of (1.2 x 10-1 to 3 x 10-5 s-1), vertical velocity of (- 0.25 to -0.4 Pa/s), and wind speed of (4 to 6 m/s). The results also illustrated that Mediterranean low pressure system is more effective than the Sudani low pressure system in producing rain storms over Iraq and surrounding regions and the most frequent occurrence of Mediterranean low rain storms occurred during the month of April, and most frequent occurrence of Sudani low rain storms occurred during the month of January. In general, rain storms in Iraq occurred more frequently during the months of January to May that during the months of October to December.