تكرار منظومات القطع الجوية فوق المنطقة الشمالية من العراق و علاقتها بالمنظومات الضغطية السطحية و العليا خلال الموسم المطير

الملخص EN

This research aims the extension of air studying and analyze the cut off systems at the pressure level 500 mb formed over the northern region due to air troughs.

The study depends or a minor climate Cycle and // seasons / beginning with 1977 / 1998 to, 2007 /2008 .

It also analyses the cut off systems assuaged with their repetition ,along with the stales jet stream lakes at the time and their appearance.

Farther, it shows the influence as the Climate change on the repenaition and the cut off system, adopting the data and the cycle 1957-1958 /1967-1968 par basis.

For comparison the low cut off on the northern region is associated with the rig six pressure systems at the level 1000mb,they are the Siberian, high And European high Sudan low Middeterean low, and Indian seasonal low where is accompanied with cut off high the the Siberian, high.

The research also has show the coincide of the jet stream curing at 300 mb towards the south at at change frome the smooth pattern or cycle pattern, with formation off cut off low .the same can be application whith 200 mb thecut off system bends towards the north in same way the jet streambeds towards the same destination taking curved from bigger than the cycle state from due to the weakness of it recurrence during that season .

the comparison between the cut off system of both climate cycle 1957 / 1958-1967 / 1968 , 1997 / 1998-2007 / 2008 shwed decrease off the frequency off cut off system recurrence at -18.8 %for 00z whith change rate of -29.04 % for 12 z whith increase in the frequency of cut off high system peaks on the region at rate of 400 % esspeciaiiy the increase of its the frequency .

for creation months of rain season which didn’t witness any reassurance during the first cycle and the change of reoccurring of cut off system bottoms was accompanied by reaccurancy of surface pressure system.