Convergence is an atmospheric condition that exists when there is a horizontal net inflow of air into a region. When air converges along the earth's surface, it is forced to rise since it cannot go downward.

Large scale convergence can lift a layer of air hundreds of kilometers across.

[Image: thickening cirrus and cirrostratus at sunset (56K)] Photograph by: Rauber

Vertical motions associated with convergence are typically much weaker than the small-scale vertical motions associated with convective processes. As a result, clouds generated through convergence, for example cirrostratus clouds, are typically less vertically developed than convective clouds.

convection

Terms for using data resources. CD-ROM available. Credits and Acknowledgments for WW2010. Department of Atmospheric Sciences (DAS) at the University of Illinois at Urbana-Champaign.

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