Trend and Change in the Frequency and Duration of the Subtropical High-Pressure System (1989-2022)

Abstract

The research aims to reveal what Iraq is exposed to a change in the general trend of frequencies and days of stay of the subtropical high throughout the year and for the frequency and duration of stay, sometimes trending towards an increase in the frequency and duration of stay of the subtropical high, while others are trending towards a decrease or decrease for the frequency and duration of stay of the subtropical high in the study area.

It turned out from the data that the frequencies of the subtropical high tend to increase in all stations for both observations , as the Mosul station recorded the lowest increase in the frequency of the subtropical high among all stations reached (0.5420 and 3.0936) repetition of both observations , respectively, while the rest of the stations recorded an increase in frequency, the highest of which was in Basra station reached (3.6174)repetition during (00)GMT and Baghdad station reached (4.6585) repetition during (1200)GMT.

It is clear through the analysis of the results that there is a change in the duration of the stay of the subtropical high towards an increase in all stations except Mosul station , which recorded a decrease in the duration of the stay of the high reached (-0.94065) days during the observation of (00)GMT, due to the decrease in the frequency of the subtropical high, while Basra station recorded the highest increase of the days of the stay of the subtropical high reached(3.688294) during the same observation, while the observation (1200)GMT 2.073845) a day in Mosul and above in Basra station reached (4.067391) days.