Circulation patterns linked to the positive sub-tropical Indian Ocean dipole
Zitieren Sie bitte immer diese URN: urn:nbn:de:bvb:20-opus-324119
- The positive phase of the subtropical Indian Ocean dipole (SIOD) is one of the climatic modes in the subtropical southern Indian Ocean that influences the austral summer inter-annual rainfall variability in parts of southern Africa. This paper examines austral summer rain-bearing circulation types (CTs) in Africa south of the equator that are related to the positive SIOD and the dynamics through which specific rainfall regions in southern Africa can be influenced by this relationship. Four austral summer rain-bearing CTs were obtained. AmongThe positive phase of the subtropical Indian Ocean dipole (SIOD) is one of the climatic modes in the subtropical southern Indian Ocean that influences the austral summer inter-annual rainfall variability in parts of southern Africa. This paper examines austral summer rain-bearing circulation types (CTs) in Africa south of the equator that are related to the positive SIOD and the dynamics through which specific rainfall regions in southern Africa can be influenced by this relationship. Four austral summer rain-bearing CTs were obtained. Among the four CTs, the CT that featured (i) enhanced cyclonic activity in the southwest Indian Ocean; (ii) positive widespread rainfall anomaly in the southwest Indian Ocean; and (iii) low-level convergence of moisture fluxes from the tropical South Atlantic Ocean, tropical Indian Ocean, and the southwest Indian Ocean, over the south-central landmass of Africa, was found to be related to the positive SIOD climatic mode. The relationship also implies that positive SIOD can be expected to increase the amplitude and frequency of occurrence of the aforementioned CT. The linkage between the CT related to the positive SIOD and austral summer homogeneous regions of rainfall anomalies in Africa south of the equator showed that it is the principal CT that is related to the inter-annual rainfall variability of the south-central regions of Africa, where the SIOD is already known to significantly influence its rainfall variability. Hence, through the large-scale patterns of atmospheric circulation associated with the CT, the SIOD can influence the spatial distribution and intensity of rainfall over the preferred landmass through enhanced moisture convergence.…
Autor(en): | Chibuike Chiedozie IbebuchiORCiD |
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URN: | urn:nbn:de:bvb:20-opus-324119 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Philosophische Fakultät (Histor., philolog., Kultur- und geograph. Wissensch.) / Institut für Geographie und Geologie |
Sprache der Veröffentlichung: | Englisch |
Titel des übergeordneten Werkes / der Zeitschrift (Englisch): | Advances in Atmospheric Sciences |
ISSN: | 0256-1530 |
Erscheinungsjahr: | 2023 |
Band / Jahrgang: | 40 |
Heft / Ausgabe: | 1 |
Seitenangabe: | 110-128 |
Originalveröffentlichung / Quelle: | Advances in Atmospheric Sciences (2023) 40:1, 110-128 DOI: 10.1007/s00376-022-2017-2 |
DOI: | https://doi.org/10.1007/s00376-022-2017-2 |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 526 Mathematische Geografie |
9 Geschichte und Geografie / 91 Geografie, Reisen / 910 Geografie, Reisen | |
Freie Schlagwort(e): | South Indian Ocean; circulation types; moisture convergence; rainfall; subtropical Indian Ocean dipole |
Datum der Freischaltung: | 17.01.2024 |
Lizenz (Deutsch): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |