In the hot seat: Insolation, ENSO, and vegetation in the african tropics

Sarah J. Ivory, Joellen Russell, Andrew Cohen

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

African climate is changing at rates unprecedented in the Late Holocene with profound implications for tropical ecosystems and the global hydrologic cycle. Understanding the specific climate drivers behind tropical ecosystem change is critical for both future and paleomodeling efforts. However, linkages between climate and vegetation in the tropics have been extremely controversial. The Normalized Difference Vegetation Index (NDVI) is a satellite-derived index of vegetation productivity with a high spatial and temporal resolution. Here we use regression analysis to show that NDVI variability in Africa is primarily correlated with the interannual extent of the Intertropical Convergence Zone (ITCZ). Our results indicate that interannual variability of the ITCZ, rather than sea surface temperatures or teleconnections to middle/high latitudes, drives patterns in African vegetation resulting from the effects of insolation anomalies and El Niño-Southern Oscillation (ENSO) events on atmospheric circulation. Global controls on tropical atmospheric circulation allow for spatially coherent reconstruction of interannual vegetation variability throughout Africa on many time scales through regulation of dry season length and moisture convergence, rather than precipitation amount. Key Points Atmospheric variability has a dramatic effect on tropical African vegetation. ITCZ position and intensity result from variations in insolation and ENSO. Growing season vegetation controls are both rainfall and dry season length.

Original languageEnglish (US)
Pages (from-to)1347-1358
Number of pages12
JournalJournal of Geophysical Research: Space Physics
Volume118
Issue number4
DOIs
StatePublished - 2013

Fingerprint

seats
Tropics
insolation
Southern Oscillation
Incident solar radiation
Seats
vegetation
tropical regions
oscillation
tropics
solar radiation
intertropical convergence zone
atmospheric circulation
climate
normalized difference vegetation index
ecosystems
dry season
NDVI
Ecosystems
hydrologic cycle

Keywords

  • ENSO
  • insolation
  • ITCZ
  • NDVI
  • tropical climate
  • vegetation

ASJC Scopus subject areas

  • Soil Science
  • Forestry
  • Water Science and Technology
  • Palaeontology
  • Atmospheric Science
  • Aquatic Science
  • Ecology

Cite this

In the hot seat : Insolation, ENSO, and vegetation in the african tropics. / Ivory, Sarah J.; Russell, Joellen; Cohen, Andrew.

In: Journal of Geophysical Research: Space Physics, Vol. 118, No. 4, 2013, p. 1347-1358.

Research output: Contribution to journalArticle

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