Month Of April Research Articles

The work studied the relationship between polar jet stream and surface low pressure in April's months during years from 2014 to 2016 which the polar jet passes with high frequencies over the area of study. The study presents the structure of polar jet that affects significantly in the intensity of the low pressure system at the surface. The structuredid not repeat regularly during April's months for the years from 2014 to 2016 and it was two structures, continuous and discontinuous with different percentage ratios from a year to year. The percentages ratios of discontinuous jet-types were in2014 about 36 %, 6 % in 2015, 92 % in 2016 which declared to estimate low pressure center value on the surface which need the corrected recognizing the polar jet-type depending on its structure. The relationship between low pressure center value and the lowest polar jet geopotential height was during April 2014 which was generally direct relationship with continuous jet-type while it was indirect relationship with discontinuous jet-type. The mixing continuous and discontinuous jet-types data in same year will distorted that relationship. The discontinuous jet-type structure was significant to limit the relationship between low pressure center on surface and geopotential height which was direct relationship with small ratio of discontinuous as April 2015 jet-type and high ratio as April 2016 while with ratio near from middle as April 2014 relationship was distorted. The study also revealed the low pressure center value would be less withthe discontinuous jet-type if there were same geopotential height values of continuous and discontinuous jet-type