WW2010
University of Illinois

WW2010
 
  welcome
 
> online guides
 
  archives
 
  educational cd-rom
 
  current weather
 
  about ww2010
 
  index

Online Guides
 
  introduction
 
> meteorology
 
  remote sensing
 
  reading maps
 
  projects, activities

Meteorology
 
  introduction
 
  air masses, fronts
 
> clouds, precipitation
 
  el nino
 
  forces, winds
 
  hurricanes
 
  hydrologic cycle
 
  light, optics
 
  midlatitude cyclones
 
  severe storms
 
  weather forecasting

Clouds, Precipitation
 
  introduction
 
> mechanisms
 
  precip processes
 
  high level clouds
 
  mid level clouds
 
  low level clouds
 
  vertically developed
 
  other cloud types

Mechanisms
 
  convection
 
> convergence
 
  orographic
 
  fronts

User Interface
 
  graphics
> text

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
.
Lifting by Convergence
broad lifting of an entire layer of air

When the horizontal flow of air converges along the earth's surface, it must go somewhere. Since it is not able to go into the ground, it rises.

Large scale convergence lifts a layer of air (sometimes hundreds of kilometers across), the air cooling as it rises. If the rising air cools to its saturation point, the water vapor will condense out to form cloud droplets.

[Image: thickening cirrus and cirrostratus at sunset (65K)]

Vertical motions associated with convergence lifting are typically much weaker than the stronger small scale vertical motions associated with convective processes. As a result, clouds generated through convergence are less vertically developed. Cirrostratus clouds is one cloud type that develops from convergence lifting.

It is also important to note that convergence occurs not only at the surface, but higher levels as well.


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.