Using the Polar Jet Stream Core Wind Speed to Estimate the Surface Low Pressure System value during winter

• Main Author: hazim D. mohsin
• Format: Article
• Language: Arabic
• Published: Al-Mustansiriyah University 2019-08-01
• Series: Mustansiriyah Journal of Science
• Online Access: http://mjs.uomustansiriyah.edu.iq/ojs1/index.php/MJS/article/view/448

The work studied the relationship between polar jet stream core speed at 300 hPa level and the surface low pressure system on winter seasons during years from 2014 to 2016. Februaries were chosen from winter seasons which the polar jet stream passes with high frequencies over the area of study. The study presented that the structure of polar jet was almost continuous jet-type structure that the jet core was easy to recognize and it had indirect relationship with the low pressure systems at surface. the Pearson's (R) statistical test used to show the strength of that relationship which accessible values were between (0.6 - 1) that presented the core speed values as a good element to derive equation connecting between the low pressure system value in (hPa) at surface and core speed value in (kt) at 300 hPa level . The simple linear regression technique is used to drive the equation that connects between the low pressure system and the jet core speed value which was (Low pressure center value (hPa) =1042.57 ̶ (0.307 × core speed (kt) )) . The equation was tested against some jet stream cases at 300 hPa that were the highest value of the jet core speed, the lowest and middle selected value which presented the percentage errors were between (0.03-0.09). the chart analyzing presented the lowest low pressure system center corresponded the highest the jet core speed values as shown in 11 Feb., 2015 at 00 UTC which the core speed was 150 (kt) corresponding the surface low pressure system which was 993 (hPa)