Open AccessEvidence of Tropical Forcing of the 6.5-Day Wave from Lightning Observations over Africa
Author(s) -
Themis Chronis,
Earle Williams,
Emmanouil N. Anagnostou
Publication year - 2007
Publication title -
journal of the atmospheric sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.853
H-Index - 173
eISSN - 1520-0469
pISSN - 0022-4928
DOI - 10.1175/jas4021.1
Subject(s) - outgoing longwave radiation , climatology , lightning (connector) , forcing (mathematics) , environmental science , convection , proxy (statistics) , atmospheric sciences , deep convection , meteorology , geology , geography , physics , power (physics) , quantum mechanics , machine learning , computer science
A study employing observations and climatic reanalysis data is concerned with links between convection and the well-documented 6.5-day stratospheric global wave. Observations from a long-range lightning detection network, known as ZEUS, reveal an in-phase behavior between the maximization of daily lightning activity over Africa and the intensification of the wave. To extend the observations on a climatological basis, the authors make use of the outgoing longwave radiation (OLR) as proxy for convection and the surface level pressure (SLP) as an indicator of atmospheric column forcing. Cross-spectral analysis shows significant peaks in coherency between OLR and SLP, apparent only over equatorial Africa and South America (Amazon basin), while strong coherency in this frequency band is absent over the Maritime Continent.