Editing Intertropical Convergence Zone (section)

==South Pacific convergence zone==
[[File:Omega-500-july-era40-1979.png|thumb|left|Vertical air velocity at 500 hPa, July average. Ascent (negative values) is concentrated close to the [[solar equator]]; descent (positive values) is more diffuse]]

The [[South Pacific convergence zone]] (SPCZ) is a reverse-oriented, or west-northwest to east-southeast aligned, trough extending from the west Pacific warm pool southeastwards towards [[French Polynesia]]. It lies just south of the equator during the Southern Hemisphere warm season, but can be more extratropical in nature, especially east of the [[International Date Line]]. It is considered the largest and most important piece of the ITCZ, and has the least dependence upon heating from a nearby [[land mass]] during the summer than any other portion of the [[monsoon trough]].<ref>E. Linacre and B. Geerts. [http://www-das.uwyo.edu/~geerts/cwx/notes/chap12/spcz.html Movement of the South Pacific convergence zone] Retrieved on 2006-11-26.</ref>  The southern ITCZ in the eastern tropical Pacific and southern tropical Atlantic, known as the SITCZ, occurs during the Southern Hemisphere fall between [[3rd parallel south|3°]] and [[10th parallel south|10° south]] of the equator east of the [[140th meridian west]] longitude during cool or neutral [[El Niño–Southern Oscillation]] (ENSO) patterns. When ENSO reaches its warm phase, otherwise known as El Niño, the tongue of lowered [[sea surface temperature]]s due to upwelling off the South American continent disappears, which causes this convergence zone to vanish as well.<ref>{{cite web|author1=Semyon A. Grodsky |author2=James A. Carton |url=http://www.atmos.umd.edu/~carton/pdfs/grodsky&carton03.pdf|date=2003-02-15|publisher=University of Maryland, College Park|title=The Intertropical Convergence Zone in the South Atlantic and the Equatorial Cold Tongue|access-date=2009-06-05}}</ref>