Iran Meteorology Society (IMS) Journal of Meteorology and Atmospheric Science 2645-7261 4 4 2022 02 20 Investigating role of the Quasi-Biennial Oscillation in the variability of the Stratospheric-Tropospheric circulation of the Polar Vortex in relation to the atmospheric circulation changes over Southwest Asia and Iran. Investigating role of the Quasi-Biennial Oscillation in the variability of the Stratospheric-Tropospheric circulation of the Polar Vortex in relation to the atmospheric circulation changes over Southwest Asia and Iran. 308 325 170990 10.22034/jmas.2023.352441.1181 FA Hassan Haji Mohamadi Journal Article 2021 08 02 One of the most important dominant oscillations of the stratosphere is the Quasi-Biennial Oscillation, which has important effects on atmospheric circulation in extratropical regions and especially large-scale systems such as polar ice caps. In this regard, it was tried to study the role of QBO in the atmospheric variability of stratospheric-tropospheric polar convection in connection with atmospheric circulation over West Asia and Iran. For this purpose, data from the National Center of Environmental Prediction/ National Center of Atmospheric Sciences (NCEP/NCAR) and the Singapore Center were used during the statistical period of 1948-2020. The results indicated that the changes in atmospheric circulation in the stratosphere in the winter season include the decrease in geopotential height in the polar cap and its increase in the North Pacific Ocean and North West Asia. But this situation did not show any significant relationship in the summer season of the Northern Hemisphere stratosphere. In the spring season, the maximum correlation was with the outer edge of the polar ice cap and in mid-latitudes, which had a high negative correlation. In the autumn season, the increase in geopotential height in the southern parts of the Middle East in the stratosphere and in the middle and lower troposphere leads to a decrease in geopotential height over the north of Iran. One of the most important dominant oscillations of the stratosphere is the Quasi-Biennial Oscillation, which has important effects on atmospheric circulation in extratropical regions and especially large-scale systems such as polar ice caps. In this regard, it was tried to study the role of QBO in the atmospheric variability of stratospheric-tropospheric polar convection in connection with atmospheric circulation over West Asia and Iran. For this purpose, data from the National Center of Environmental Prediction/ National Center of Atmospheric Sciences (NCEP/NCAR) and the Singapore Center were used during the statistical period of 1948-2020. The results indicated that the changes in atmospheric circulation in the stratosphere in the winter season include the decrease in geopotential height in the polar cap and its increase in the North Pacific Ocean and North West Asia. But this situation did not show any significant relationship in the summer season of the Northern Hemisphere stratosphere. In the spring season, the maximum correlation was with the outer edge of the polar ice cap and in mid-latitudes, which had a high negative correlation. In the autumn season, the increase in geopotential height in the southern parts of the Middle East in the stratosphere and in the middle and lower troposphere leads to a decrease in geopotential height over the north of Iran. https://www.ims-jmas.net/article_170990_61248ba7a941cc629c66125032d5236e.pdf