NDLI: Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales

Content Provider	Springer Nature Link
Author	Puaud, Yohan Pohl, Benjamin Fauchereau, Nicolas Macron, Clémence Beltrando, Gérard
Copyright Year	2016
Abstract	This paper investigates and quantifies co-variability between large-scale convection in the South American and Southern African sectors at different timescales (interannual, intraseasonal and synoptic), during the austral summer seasons (November–February) from 1979 to 2012. Multivariate analyses (Canonical Correlation Analysis and Principal Component Analysis) are applied to daily outgoing longwave radiation (OLR, used as a proxy for atmospheric convection) anomalies to extract the principal modes of variability and co-variability in each and between both regions, filtered to consider the appropriate time-scales. At the interannual timescale, results confirm the predominant role of El Niño Southern Oscillation (ENSO), favoring enhanced convection over both southeastern Brazil and northern Argentina on the one hand, and tropical Africa and the western Indian Ocean on the other hand. At the intraseasonal timescale, the leading mode of co-variability is related to modulations of large-scale atmospheric convection over most of South America, and 10 days later, tropical Southern Africa. This mode accounts for the impacts of the Madden–Julian-oscillation (MJO) over these regions: identifying robust co-variability at the intraseasonal timescale between both regions require thus to consider a temporal shift between the two sectors. At the synoptic scale, however, co-variability consists mostly of a synchronous modulation of the large-scale atmospheric convection over the South American and Southern African sectors. This results from the development of concomitant Rossby waves forming a continuous wave train over the South Atlantic in the mid-latitudes, affecting both the South Atlantic and South Indian Convergence Zones. Among the days when convection shows significant anomalies (30 % of the total days in each sector), this synchronous mode occurs about 25 % of the time, individual Rossby waves modulating convection over one single region only during the remaining 75 % events. Another mode of co-variability, involving a single Rossby wave modulating the convection first over the Americas, and 4 days later over Africa, appears as sensibly weaker than the synchronous mode, suggesting that the “wave train” mode occurs more frequently than the development and propagation of a single wave that could affect both regions.
Starting Page	4029
Ending Page	4050
Page Count	22
File Format	PDF
ISSN	09307575
Journal	Climate Dynamics
Volume Number	48
Issue Number	11-12
e-ISSN	14320894
Language	English
Publisher	Springer Berlin Heidelberg
Publisher Date	2016-08-17
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	El Niño southern oscillation Madden–Julian oscillation Rossby waves Co-variability Atmospheric convection South Atlantic convergence zone South Indian convergence zone Geophysics/Geodesy Climatology Oceanography
Content Type	Text
Resource Type	Article
Subject	Atmospheric Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales.

Intraseasonal variability of the Atlantic Intertropical Convergence Zone during austral summer and winter

Interactions between synoptic, intraseasonal and interannual convective variability over Southern Africa

Interannual variability of seasonal rainfall over the Cape south coast of South Africa and synoptic type association

Interannual variability of the South Pacific Convergence Zone and implications for tropical cyclone genesis

Processes controlling the surface temperature signature of the Madden–Julian Oscillation in the thermocline ridge of the Indian Ocean

Arctic sea ice and the Madden–Julian Oscillation (MJO)

The role of synoptic and intraseasonal anomalies in the life cycle of summer rainfall extremes over South America

Factors controlling January–April rainfall over southern India and Sri Lanka

Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales

Similar Documents

Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales.

Intraseasonal variability of the Atlantic Intertropical Convergence Zone during austral summer and winter

Interactions between synoptic, intraseasonal and interannual convective variability over Southern Africa

Interannual variability of seasonal rainfall over the Cape south coast of South Africa and synoptic type association

Interannual variability of the South Pacific Convergence Zone and implications for tropical cyclone genesis

Processes controlling the surface temperature signature of the Madden–Julian Oscillation in the thermocline ridge of the Indian Ocean

Arctic sea ice and the Madden–Julian Oscillation (MJO)

The role of synoptic and intraseasonal anomalies in the life cycle of summer rainfall extremes over South America

Factors controlling January–April rainfall over southern India and Sri Lanka

Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales