Effect of Arabian subtropical high-pressure intensity on the ITCZ zonal displacement pattern in Northeast Africa

In this study, the role of Arabian subtropical high-pressure (ASHP) positive and negative phases on displacement and refraction in the ITCZ zonal position was investigated. Therefore, the wave activity at the atmospheric levels was calculated in the domain of the ASHP's establishment and expansion. The results were compared with changes in the ITCZ zonal position in the positive and negative critical phase samples of the high pressure. The results of flux measurements in the domain of the ASHP's establishment and expansion show that in the positive phase, the northern flows have overcome the region and the meridian gradient has been created and increased. This condition has led to the strengthening of ASHP. But in the negative phase, due to the increase in the amount of input flux in the eastern boundary, the place of propagation of the waves has a more southern route, which enters the domain by overcoming zonal flows. Zonal flows have led to a decrease in the meridian gradient and, consequently, to a reduction in the vorticity of the flow, which is a factor in weakening ASHP. The study of ITCZ's position in the sample phases also confirmed the adaptation of its changes in the positive phase every 3 months to the strong southern flux flow. So, ITCZ has a more southern position and severe refraction compared to the negative phase. In general, ASHP is one of the centers of effective activity in the unconventional movements of the ITCZ belt in the cold seasons by creating south-southwest flows.