Iran Meteorology Society (IMS) Journal of Meteorology and Atmospheric Science 2645-7261 8 Number 2 2025 12 22 The effect of the Indian Dipolar Oscillation on the intensity of the Madden-Julian Oscillation in relation to the atmospheric circulation of Iran and the Middle East. The effect of the Indian Dipolar Oscillation on the intensity of the Madden-Julian Oscillation in relation to the atmospheric circulation of Iran and the Middle East. 31 48 247771 10.22034/jmas.2026.532607.1244 FA Hassan Haji Mohamadi Faramarz Khosh Akhlagh Associate Professor of Climatology, University of Tehran 0000-0003-4602-7084 Journal Article 2025 07 11 In this regard, and in order to investigate the effect of the Indian Dipolar Oscillation on the intensity of the Madden-Julian oscillation in relation to Iranian precipitation, the gridded data of the National Center for Environmental Prediction/Atmospheric Sciences (NCEP/NCAR) for the atmosphere-ocean circulation and the RMM data for the intensity of the Madden-Julian index between 1991 and 2020 were used. To understand the atmospheric mechanism, dynamical quantities of potential velocity and divergent wind were used. The results showed that the strongest IOD occurred in 2019, which lasted from May to November. During this period, the MJO was in phases 7 to 3 in most months, indicating the activity of this system in the Indian Ocean and Africa. As this situation continued, it was observed that the sea surface temperature anomaly reached more than 4 degrees Celsius compared to its long-term average, and on the other hand, a sharp decrease in the OLR index was observed over Africa, India, and South Asia. Correlations showed that the omega index and OLR in the Asian tropics indicated a high and significant relationship between the Indian Ocean surface temperature in the mentioned time period and the representative indices. In this regard, and in order to investigate the effect of the Indian Dipolar Oscillation on the intensity of the Madden-Julian oscillation in relation to Iranian precipitation, the gridded data of the National Center for Environmental Prediction/Atmospheric Sciences (NCEP/NCAR) for the atmosphere-ocean circulation and the RMM data for the intensity of the Madden-Julian index between 1991 and 2020 were used. To understand the atmospheric mechanism, dynamical quantities of potential velocity and divergent wind were used. The results showed that the strongest IOD occurred in 2019, which lasted from May to November. During this period, the MJO was in phases 7 to 3 in most months, indicating the activity of this system in the Indian Ocean and Africa. As this situation continued, it was observed that the sea surface temperature anomaly reached more than 4 degrees Celsius compared to its long-term average, and on the other hand, a sharp decrease in the OLR index was observed over Africa, India, and South Asia. Correlations showed that the omega index and OLR in the Asian tropics indicated a high and significant relationship between the Indian Ocean surface temperature in the mentioned time period and the representative indices. https://www.ims-jmas.net/article_247771_0f9b867c11201ff3276bcc611c5c3e5a.pdf