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

Forces, Winds
 
  introduction
 
  pressure
 
  pressure gradient
 
  coriolis force
 
  geostrophic wind
 
  gradient wind
 
  friction
 
  boundary layer wind
 
  sea breezes
 
> land breezes

Land Breezes
 
  low-level cooling
 
  onshore flow aloft
 
> circulation

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.
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Land Breeze Develops
cooler air flows offshore

Since the pressure at any location is determined by the weight of the air above it, the accumulation of air at higher levels causes the pressure at levels below to increase. In the case of a developing land-breeze circulation, an area of high pressure develops over land at the surface in response to the accumulation of air at higher levels by onshore flow. Conversely, an area of surface low pressure develops over water in response to the removal of air from higher levels.

These areas of high and low pressure establish a surface pressure gradient which generates an offshore flow of air at the surface, or land breeze.

Vertical motions are induced in response to the horizontally moving air. Over water, for example, offshore flow causes air to pile up at lower levels while onshore flow removes air from higher levels. As a result, air rises up from lower levels to replace the air that is being removed aloft.

On the other hand, over land, air is accumulated at higher levels while being removed from lower levels. In response, air descends from higher levels to replace the air that is being removed from lower levels. These rising and sinking motions complete the loop that makes up the land-breeze circulation.



onshore flow aloft
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.

Hurricanes