Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan

This work investigates the factors influencing summer (June–September: JJAS) monsoon rainfall variability over Sudan using monthly datasets from multiple sources from 1980 to 2018. Sequential Mann-Kendall, Empirical Orthogonal Function (EOF), composite and correlation analysis were utilized to inves...

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Main Authors: Alriah, Mohamed Abdallah Ahmed, Bi, Shuoben, Shahid, Shamsuddin, Nkunzimana, Athanase, Ayugi, Brian, Ali, Arfan, Bilal, Muhammad, Teshome, Asaminew, Sarfo, Isaac, Elameen, Ayman M.
Format: Article
Published: Elsevier Ltd 2021
Subjects:
_version_ 1796866104289656832
author Alriah, Mohamed Abdallah Ahmed
Bi, Shuoben
Shahid, Shamsuddin
Nkunzimana, Athanase
Ayugi, Brian
Ali, Arfan
Bilal, Muhammad
Teshome, Asaminew
Sarfo, Isaac
Elameen, Ayman M.
author_facet Alriah, Mohamed Abdallah Ahmed
Bi, Shuoben
Shahid, Shamsuddin
Nkunzimana, Athanase
Ayugi, Brian
Ali, Arfan
Bilal, Muhammad
Teshome, Asaminew
Sarfo, Isaac
Elameen, Ayman M.
author_sort Alriah, Mohamed Abdallah Ahmed
collection ePrints
description This work investigates the factors influencing summer (June–September: JJAS) monsoon rainfall variability over Sudan using monthly datasets from multiple sources from 1980 to 2018. Sequential Mann-Kendall, Empirical Orthogonal Function (EOF), composite and correlation analysis were utilized to investigate the spatio-temporal rainfall variability in Sudan, and its associated circulations and teleconnections. Results revealed a significant increase in JJAS rainfall during the study period. The wet condition was found with accompanying convergence winds at low levels and divergence in the upper levels, while the dry conditions were due to the weakening of convergence moisture transport. A hot Sea Surface Temperature anomalies over the Eastern Pacific Ocean (Nino3.4) are associated with dry conditions,whilst cold anomalies are associated with wet conditions. There was correlation between the first EOFs JJAS rainfall and EOFs SSTs teleconnections NINO3.4. IOD, PDO, and NAO, exhibited moderate to strong positive correlations of 62.5% in average. However, the second mode of SSTs teleconnections EOFS revealed a low positive correlation of 46.4% in average, excluding the strong negative impact of NINO3.4–73%. In different regions in Sudan, the influences of NINO3.4 are much stronger in the south, west and central regions (0.71, −0.71 and −0.72). And IOD exhibited much impact in the south and west regions (0.73, 0.74). The southern and western regions had the highest correlation with PDO and NAO. ENSO and IOD also tend to extend summer rainfall season. Therefore, this research serves as the baseline study for further work to examine the impact of SSTs teleconnections on summer rainfall in Sudan (starting, cessation and extremes), thereby providing a reasonable basis for monitoring and predicting similar conditions in the future.
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spelling utm.eprints-958502022-06-20T08:46:06Z http://eprints.utm.my/95850/ Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan Alriah, Mohamed Abdallah Ahmed Bi, Shuoben Shahid, Shamsuddin Nkunzimana, Athanase Ayugi, Brian Ali, Arfan Bilal, Muhammad Teshome, Asaminew Sarfo, Isaac Elameen, Ayman M. TA Engineering (General). Civil engineering (General) This work investigates the factors influencing summer (June–September: JJAS) monsoon rainfall variability over Sudan using monthly datasets from multiple sources from 1980 to 2018. Sequential Mann-Kendall, Empirical Orthogonal Function (EOF), composite and correlation analysis were utilized to investigate the spatio-temporal rainfall variability in Sudan, and its associated circulations and teleconnections. Results revealed a significant increase in JJAS rainfall during the study period. The wet condition was found with accompanying convergence winds at low levels and divergence in the upper levels, while the dry conditions were due to the weakening of convergence moisture transport. A hot Sea Surface Temperature anomalies over the Eastern Pacific Ocean (Nino3.4) are associated with dry conditions,whilst cold anomalies are associated with wet conditions. There was correlation between the first EOFs JJAS rainfall and EOFs SSTs teleconnections NINO3.4. IOD, PDO, and NAO, exhibited moderate to strong positive correlations of 62.5% in average. However, the second mode of SSTs teleconnections EOFS revealed a low positive correlation of 46.4% in average, excluding the strong negative impact of NINO3.4–73%. In different regions in Sudan, the influences of NINO3.4 are much stronger in the south, west and central regions (0.71, −0.71 and −0.72). And IOD exhibited much impact in the south and west regions (0.73, 0.74). The southern and western regions had the highest correlation with PDO and NAO. ENSO and IOD also tend to extend summer rainfall season. Therefore, this research serves as the baseline study for further work to examine the impact of SSTs teleconnections on summer rainfall in Sudan (starting, cessation and extremes), thereby providing a reasonable basis for monitoring and predicting similar conditions in the future. Elsevier Ltd 2021-11-15 Article PeerReviewed Alriah, Mohamed Abdallah Ahmed and Bi, Shuoben and Shahid, Shamsuddin and Nkunzimana, Athanase and Ayugi, Brian and Ali, Arfan and Bilal, Muhammad and Teshome, Asaminew and Sarfo, Isaac and Elameen, Ayman M. (2021) Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan. Journal of Atmospheric and Solar-Terrestrial Physics, 225 . pp. 1-15. ISSN 1364-6826 http://dx.doi.org/10.1016/j.jastp.2021.105751 DOI:10.1016/j.jastp.2021.105751
spellingShingle TA Engineering (General). Civil engineering (General)
Alriah, Mohamed Abdallah Ahmed
Bi, Shuoben
Shahid, Shamsuddin
Nkunzimana, Athanase
Ayugi, Brian
Ali, Arfan
Bilal, Muhammad
Teshome, Asaminew
Sarfo, Isaac
Elameen, Ayman M.
Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title_full Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title_fullStr Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title_full_unstemmed Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title_short Summer monsoon rainfall variations and its association with atmospheric circulations over Sudan
title_sort summer monsoon rainfall variations and its association with atmospheric circulations over sudan
topic TA Engineering (General). Civil engineering (General)
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