Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans
This study presents the relationship between Tanzania short rain variability and the sea surface temperature (SST) over the Southern Oceans from 1950 to 2017. It is found that the warm SST anomalies to the east of Australia (EA-SST) and the southern Atlantic Ocean (SA-SST) are significantly negative...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-06-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.922172/full |
| _version_ | 1811245649658642432 |
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| author | Exavery Kisesa Makula Exavery Kisesa Makula Exavery Kisesa Makula Botao Zhou Botao Zhou |
| author_facet | Exavery Kisesa Makula Exavery Kisesa Makula Exavery Kisesa Makula Botao Zhou Botao Zhou |
| author_sort | Exavery Kisesa Makula |
| collection | DOAJ |
| description | This study presents the relationship between Tanzania short rain variability and the sea surface temperature (SST) over the Southern Oceans from 1950 to 2017. It is found that the warm SST anomalies to the east of Australia (EA-SST) and the southern Atlantic Ocean (SA-SST) are significantly negatively correlated with the OND rainfall throughout Tanzania, signifying that the warmer (cooler) than normal EA-SST and SA-SST tend to cause a suppressed (enhanced) OND rainfall in Tanzania. Further investigation indicates that the above-normal SA-SST anomalies are linked to the changes of Walker-type circulation over the Atlantic Ocean, with the low-level (upper-level) divergence (convergence) occurring over the study region, which suppresses the in-situ convection and hence decreases the rainfall over Tanzania. The above-normal SA-SST anomalies are associated with the upper-level wave patterns propagating from the southern Atlantic Ocean, resulting in the formation of cyclonic anomalies over the target region. The upper-level cyclonic anomalies formed favor the subsidence of airflows over Tanzania and hence reduce rainfall. The local moisture and dynamical conditions also support the atmospheric circulations observed, whereby warm EA-SST and SA-SST anomalies are associated with the westerly moisture flux over the Indian Ocean moving away from Tanzania and the descending motion over Tanzania. Hence, close monitoring of SST anomalies over these regions might be useful in updating OND rainfall seasonal forecasts in Tanzania. |
| first_indexed | 2024-04-12T14:42:34Z |
| format | Article |
| id | doaj.art-73e0a9efdd8741c49126056736b19ee4 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-12T14:42:34Z |
| publishDate | 2022-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-73e0a9efdd8741c49126056736b19ee42022-12-22T03:28:46ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-06-011010.3389/feart.2022.922172922172Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern OceansExavery Kisesa Makula0Exavery Kisesa Makula1Exavery Kisesa Makula2Botao Zhou3Botao Zhou4Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster, Ministry of Education/International Joint Research Laboratory of Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing, ChinaSchool of Atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing, ChinaDepartment of Physics, University of Dar es Salaam, Dar es Salaam, TanzaniaCollaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster, Ministry of Education/International Joint Research Laboratory of Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing, ChinaSchool of Atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing, ChinaThis study presents the relationship between Tanzania short rain variability and the sea surface temperature (SST) over the Southern Oceans from 1950 to 2017. It is found that the warm SST anomalies to the east of Australia (EA-SST) and the southern Atlantic Ocean (SA-SST) are significantly negatively correlated with the OND rainfall throughout Tanzania, signifying that the warmer (cooler) than normal EA-SST and SA-SST tend to cause a suppressed (enhanced) OND rainfall in Tanzania. Further investigation indicates that the above-normal SA-SST anomalies are linked to the changes of Walker-type circulation over the Atlantic Ocean, with the low-level (upper-level) divergence (convergence) occurring over the study region, which suppresses the in-situ convection and hence decreases the rainfall over Tanzania. The above-normal SA-SST anomalies are associated with the upper-level wave patterns propagating from the southern Atlantic Ocean, resulting in the formation of cyclonic anomalies over the target region. The upper-level cyclonic anomalies formed favor the subsidence of airflows over Tanzania and hence reduce rainfall. The local moisture and dynamical conditions also support the atmospheric circulations observed, whereby warm EA-SST and SA-SST anomalies are associated with the westerly moisture flux over the Indian Ocean moving away from Tanzania and the descending motion over Tanzania. Hence, close monitoring of SST anomalies over these regions might be useful in updating OND rainfall seasonal forecasts in Tanzania.https://www.frontiersin.org/articles/10.3389/feart.2022.922172/fullOND rainfallTanzaniasea surface temperatureatmospheric circulationssouthern oceans |
| spellingShingle | Exavery Kisesa Makula Exavery Kisesa Makula Exavery Kisesa Makula Botao Zhou Botao Zhou Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans Frontiers in Earth Science OND rainfall Tanzania sea surface temperature atmospheric circulations southern oceans |
| title | Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans |
| title_full | Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans |
| title_fullStr | Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans |
| title_full_unstemmed | Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans |
| title_short | Linkage of Tanzania Short Rain Variability to Sea Surface Temperature Over the Southern Oceans |
| title_sort | linkage of tanzania short rain variability to sea surface temperature over the southern oceans |
| topic | OND rainfall Tanzania sea surface temperature atmospheric circulations southern oceans |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.922172/full |
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