Decadal variability of summer Southern African rainfall

Bastien Dieppois, B. Pohl, M. Rouault, M. New, N. Keenlyside, Damian Lawler

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

57 Downloads (Pure)

Abstract

Summer Southern African rainfall exhibit three significant timescales of variability over the 20th century: interdecadal (15–28 year), quasi-decadal (8–13 year) and interannual (2–8 year). Teleconnections with global sea-surface temperature and atmospheric circulation anomalies are different for each timescale. Interdecadal fluctuations in summer rainfallI are associated with the Pacific Decadal Oscillation (PDO), while quasi-decadal and interannual fluctuations are related to decadal ENSO-like, often described as the Interdecadal Pacific Oscillation (IPO), and ENSO. Annular geopotential anomalies related the Pacific SST influence strongly interact with those driven by the Southern Annular Mode (SAM). Shifts in the westerlies thus lead to anomalous low-level easterly moisture fluxes from the Mascarene region even though decadal timescales, which are not significantly expressed in the SAM.
Original languageEnglish
Title of host publicationSASAS 2015
Subtitle of host publicationApplying the weather
PublisherSouth African Society for Atmospheric Sciences
Volume31
Publication statusPublished - 2015
EventSASAS 2015: Applying the Weather - Pretoria, South Africa
Duration: 21 Sep 201522 Sep 2015
Conference number: 31

Conference

ConferenceSASAS 2015
CountrySouth Africa
CityPretoria
Period21/09/1522/09/15

Fingerprint Dive into the research topics of 'Decadal variability of summer Southern African rainfall'. Together they form a unique fingerprint.

  • Cite this

    Dieppois, B., Pohl, B., Rouault, M., New, M., Keenlyside, N., & Lawler, D. (2015). Decadal variability of summer Southern African rainfall. In SASAS 2015 : Applying the weather (Vol. 31). South African Society for Atmospheric Sciences.