El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring
This paper examines the effects of the tropical Pacific Ocean (TPO) and Indian Ocean Dipole (IOD) modes in the interannual variations of austral spring rainfall over South America (SA). The TPO mode refers to the El Niño-Southern Oscillation (ENSO). The isolated effects between IOD and TPO were esti...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/11/1437 |
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| author | Mary T. Kayano Wilmar L. Cerón Rita V. Andreoli Rodrigo A. F. Souza Itamara P. Souza Teresita Canchala |
| author_facet | Mary T. Kayano Wilmar L. Cerón Rita V. Andreoli Rodrigo A. F. Souza Itamara P. Souza Teresita Canchala |
| author_sort | Mary T. Kayano |
| collection | DOAJ |
| description | This paper examines the effects of the tropical Pacific Ocean (TPO) and Indian Ocean Dipole (IOD) modes in the interannual variations of austral spring rainfall over South America (SA). The TPO mode refers to the El Niño-Southern Oscillation (ENSO). The isolated effects between IOD and TPO were estimated, events were chosen from the residual TPO (R-TPO) or residual IOD (R-IOD), and the IOD (TPO) effects for the R-TPO (R-IOD) composites were removed from the variables. One relevant result was the nonlinear precipitation response to R-TPO and R-IOD. This feature was accentuated for the R-IOD composites. The positive R-IOD composite showed significant negative precipitation anomalies along equatorial SA east of 55° W and in subtropical western SA, and showed positive anomalies in northwestern SA and central Brazil. The negative R-IOD composite indicated significant positive precipitation anomalies in northwestern Amazon, central–eastern Brazil north of 20° S, and western subtropical SA, and negative anomalies were found in western SA south of 30° S. This nonlinearity was likely due to the distinct atmospheric circulation responses to the anomalous heating sources located in longitudinally distinct regions: the western tropical Indian Ocean and areas neighboring Indonesia. The results obtained in this study might be relevant for climate monitoring and modeling studies. |
| first_indexed | 2024-03-10T05:42:09Z |
| format | Article |
| id | doaj.art-5c3b5e4188864f36a53f2f1979be1a05 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T05:42:09Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-5c3b5e4188864f36a53f2f1979be1a052023-11-22T22:24:22ZengMDPI AGAtmosphere2073-44332021-10-011211143710.3390/atmos12111437El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral SpringMary T. Kayano0Wilmar L. Cerón1Rita V. Andreoli2Rodrigo A. F. Souza3Itamara P. Souza4Teresita Canchala5Coordenação Geral de Ciências da Terra, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas, 1758, São José dos Campos 12227-010, SP, BrazilDepartment of Geography, Faculty of Humanities, Universidad del Valle, Calle 13 # 100-00, Cali P.O. Box 25360, ColombiaEscola Superior de Tecnologia, Universidade do Estado do Amazonas, Avenue Darcy Vargas, 1200, Parque 10 de Novembro, Manaus 69065-020, AM, BrazilEscola Superior de Tecnologia, Universidade do Estado do Amazonas, Avenue Darcy Vargas, 1200, Parque 10 de Novembro, Manaus 69065-020, AM, BrazilEscola Superior de Tecnologia, Universidade do Estado do Amazonas, Avenue Darcy Vargas, 1200, Parque 10 de Novembro, Manaus 69065-020, AM, BrazilWater Resources Engineering and Soil Research Group, School of Natural Resources and Environmental Engineering, Universidad del Valle, Calle 13 # 100-00, Cali P.O. Box 25360, ColombiaThis paper examines the effects of the tropical Pacific Ocean (TPO) and Indian Ocean Dipole (IOD) modes in the interannual variations of austral spring rainfall over South America (SA). The TPO mode refers to the El Niño-Southern Oscillation (ENSO). The isolated effects between IOD and TPO were estimated, events were chosen from the residual TPO (R-TPO) or residual IOD (R-IOD), and the IOD (TPO) effects for the R-TPO (R-IOD) composites were removed from the variables. One relevant result was the nonlinear precipitation response to R-TPO and R-IOD. This feature was accentuated for the R-IOD composites. The positive R-IOD composite showed significant negative precipitation anomalies along equatorial SA east of 55° W and in subtropical western SA, and showed positive anomalies in northwestern SA and central Brazil. The negative R-IOD composite indicated significant positive precipitation anomalies in northwestern Amazon, central–eastern Brazil north of 20° S, and western subtropical SA, and negative anomalies were found in western SA south of 30° S. This nonlinearity was likely due to the distinct atmospheric circulation responses to the anomalous heating sources located in longitudinally distinct regions: the western tropical Indian Ocean and areas neighboring Indonesia. The results obtained in this study might be relevant for climate monitoring and modeling studies.https://www.mdpi.com/2073-4433/12/11/1437climate variabilitySouth AmericarainfallteleconnectionsIndian OceanRossby wave train |
| spellingShingle | Mary T. Kayano Wilmar L. Cerón Rita V. Andreoli Rodrigo A. F. Souza Itamara P. Souza Teresita Canchala El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring Atmosphere climate variability South America rainfall teleconnections Indian Ocean Rossby wave train |
| title | El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring |
| title_full | El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring |
| title_fullStr | El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring |
| title_full_unstemmed | El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring |
| title_short | El Niño-Southern Oscillation and Indian Ocean Dipole Modes: Their Effects on South American Rainfall during Austral Spring |
| title_sort | el nino southern oscillation and indian ocean dipole modes their effects on south american rainfall during austral spring |
| topic | climate variability South America rainfall teleconnections Indian Ocean Rossby wave train |
| url | https://www.mdpi.com/2073-4433/12/11/1437 |
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