Introducing new climate indices for identifying wet/dry spells within an Madden-Julian Oscillation phase Mohammad Jafar Nazemosadat, Kokab Shahgholian, Habiballah Ghaedamini, Elham Nazemosadat International Journal of Climatology, 2021 Daily values of precipitation in southwestern parts of Iran along with the corresponding Madden–Julian oscillation (MJO) phase are analysed to introduce some auxiliary indicators that can identify the wet and dry spells within a particular MJO phase. As a case study, the identification procedure focuses on phase 1 during the rainy season (Nov–Apr). The study shows that this phase contains two opposite spells, referred to as spells with pervasive precipitation (SWPP) and spells with widespread dryness (SWWD). Although the precipitation characteristics are essentially different between SWPP and SWWD, their associated MJO indices are found statistically identical. Therefore, the MJO–precipitation relationship fails to identify the wet/dry spells within an MJO phase. To resolve this deficiency, other climate indicators, which behave differently between these two spells, are introduced. The westward moisture flux over equatorial parts of the Indian Ocean and the northeastward moisture flux over the North African tropics are up to seven times stronger in the SWPP compared to SWWD. The dominance of a strong cyclonic (anticyclonic) circulation over the eastern side of the Mediterranean Sea and the negative (positive) west–east temperature gradient over southern parts of Iran are introduced as SWPP (SWWD) indicators. The study reveals that the SWPP (SWWD) coincides with a strong (weak) convection dipole that resembles the positive Indian Ocean dipole. The intensified (weakened) wind speed in the subtropical jet stream and persistence of the jet‐exit‐regions above Iran (Egypt and Saudi Arabia) are other SWPP (SWWD) indicators. Negative (positive) anomalies of sea surface temperature over the North Atlantic Ocean, the Black, Mediterranean, and Caspian Seas, as well as the Persian Gulf, signify the prevalence of the SWPP (SWWD). To the best of our knowledge, this is the first time that auxiliary indices are utilized to improve the MJO–precipitation relationship in southwestern Iran.
Predicting heavy precipitation in Southwest iran: a machine learning classification approach with atmospheric precursors and feature optimization K Shahgholian, J Bazrafshan, P Irannejad, D Ranazadeh, VP Singh Earth Systems and Environment 9 (3), 1875-1900 , 2025 2025.0 Citations: 2
Synoptic weather variables and data mining methods for predicting regional heavy precipitation over the southwest of Iran K Shahgholian, J Bazrafshan, P Irannejad 2023.0 Citations: 1
The wet and dry spells within the MJO-phase 8 and the role of ENSO and IOD on the modulation of these spells: A regional to continental-scales analysis MJ Nazemosadat, K Shahgholian, H Ghaedamini Atmospheric Research 285, 106631 , 2023 2023.0 Citations: 9
The Wet and Dry Spells within the Mjo-Phase 8 and the Role of Enso and Iod on the Characteristics of These Spells: From Regional to Continental-Scales Analysis MJ Nazemosadat, K Shahgholian Available at SSRN 4188407 , 2023 2023.0 Citations: 3
Development of a non-stationary standardized precipitation evapotranspiration index (NSPEI) for drought monitoring in a changing climate J Bazrafshan, M Cheraghalizadeh, K Shahgholian Water Resources Management 36 (10), 3523-3543 , 2022 2022.0 Citations: 35
Prediction of Regional Heavy Precipitation Occurrence in the Southwest Iran Using Synoptic Variables and Data Mining Methods K Shahgholian, J Bazrafshan, P Irannejad Iranian Journal of Soil and Water Research 53 (2), 317-332 , 2022 2022.0
Introducing new climate indices for identifying wet/dry spells within an Madden‐Julian Oscillation phase MJ Nazemosadat, K Shahgholian, H Ghaedamini, E Nazemosadat International Journal of Climatology 41, E1686-E1699 , 2021 2021.0 Citations: 6
Heavy precipitation in the southwest of Iran: association with the Madden–Julian Oscillation and synoptic scale analysis M Jafar Nazemosadat, K Shahgholian Climate Dynamics 49 (9), 3091-3109 , 2017 2017.0 Citations: 24
A synoptic-scale analysis of the episodes with and without precipitation in the southwest of Iran during the phase 1 of the MJO MJ Nazemosadat, A Rostampour, K Shahgholian Iranian Journal of Geophysics 10 (1), 73-87 , 2016 2016.0
Formation of Heavy Precipitations in Southwestern Part of Iran and its Association with the Madden-Julian Oscillation MJ Nazemosadat, K Shahgholian Water and Soil 28 (5), 1072-1083 , 2015 2015.0 Citations: 3
Predicting Regional Heavy Precipitation Occurrences in the Southwest Iran Using Machine Learning Models and Atmospheric Variables K Shahgholian, J Bazrafshan, P Irannejad, D Ranazadeh, VP Singh Available at SSRN 5090878 , 0
MOST CITED SCHOLAR PUBLICATIONS
Development of a non-stationary standardized precipitation evapotranspiration index (NSPEI) for drought monitoring in a changing climate J Bazrafshan, M Cheraghalizadeh, K Shahgholian Water Resources Management 36 (10), 3523-3543 , 2022 2022.0 Citations: 35
Heavy precipitation in the southwest of Iran: association with the Madden–Julian Oscillation and synoptic scale analysis M Jafar Nazemosadat, K Shahgholian Climate Dynamics 49 (9), 3091-3109 , 2017 2017.0 Citations: 24
The wet and dry spells within the MJO-phase 8 and the role of ENSO and IOD on the modulation of these spells: A regional to continental-scales analysis MJ Nazemosadat, K Shahgholian, H Ghaedamini Atmospheric Research 285, 106631 , 2023 2023.0 Citations: 9
Introducing new climate indices for identifying wet/dry spells within an Madden‐Julian Oscillation phase MJ Nazemosadat, K Shahgholian, H Ghaedamini, E Nazemosadat International Journal of Climatology 41, E1686-E1699 , 2021 2021.0 Citations: 6
The Wet and Dry Spells within the Mjo-Phase 8 and the Role of Enso and Iod on the Characteristics of These Spells: From Regional to Continental-Scales Analysis MJ Nazemosadat, K Shahgholian Available at SSRN 4188407 , 2023 2023.0 Citations: 3
Formation of Heavy Precipitations in Southwestern Part of Iran and its Association with the Madden-Julian Oscillation MJ Nazemosadat, K Shahgholian Water and Soil 28 (5), 1072-1083 , 2015 2015.0 Citations: 3
Predicting heavy precipitation in Southwest iran: a machine learning classification approach with atmospheric precursors and feature optimization K Shahgholian, J Bazrafshan, P Irannejad, D Ranazadeh, VP Singh Earth Systems and Environment 9 (3), 1875-1900 , 2025 2025.0 Citations: 2
Synoptic weather variables and data mining methods for predicting regional heavy precipitation over the southwest of Iran K Shahgholian, J Bazrafshan, P Irannejad 2023.0 Citations: 1
Prediction of Regional Heavy Precipitation Occurrence in the Southwest Iran Using Synoptic Variables and Data Mining Methods K Shahgholian, J Bazrafshan, P Irannejad Iranian Journal of Soil and Water Research 53 (2), 317-332 , 2022 2022.0
A synoptic-scale analysis of the episodes with and without precipitation in the southwest of Iran during the phase 1 of the MJO MJ Nazemosadat, A Rostampour, K Shahgholian Iranian Journal of Geophysics 10 (1), 73-87 , 2016 2016.0
Predicting Regional Heavy Precipitation Occurrences in the Southwest Iran Using Machine Learning Models and Atmospheric Variables K Shahgholian, J Bazrafshan, P Irannejad, D Ranazadeh, VP Singh Available at SSRN 5090878 , 0
