University:
California State University, Northridge
Course:
GEOG 103 | Weather
Academic year:

2024
Views:

174

Pages:

1
Author:

Harley Phelps

Geography 103 - Weather Summary notes. Winds and vertical air motion Winds winds aloft flow parallel to isobars winds at surface flow in the same direction as those aloft but cross the isobar of lower pressure due to friction Vertical air motion surface lows (cyclones) cause air to blow inwards = convergence -> air must rise -> divergence aloft. Therefore surface lows are associated with rising air, clouds, precipitation. surface highs (anticyclones) cause air to blow outwards = divergence at surface -> convergence aloft -> subsidence of air. Therefore surface highs are associated with sinking (and warming) air and fair weather. divergence at surface corresponds to convergence aloft convergence at surface corresponds to divergence aloft lake-effect snows – convergence of air at surface on far side of lake causes air to rise and clouds/precipitation/snow Scales of Atmospheric motion 3 scales: local winds: eg. land and sea breezes – during the day the land heats up more quickly than water and produces a thermal low at the surface. Air rises above low. H formed aloft in warm column of air above surface L. L formed aloft in cool column of air above cold water. Thermal circulation sets up sea breeze during day. At night land cools faster and circulation reverses. synoptic (weather map scale) eg. Santa Ana winds initiated by H over Great Basin – forces air downslope from elevated desert plateau eg monsoons global scale (affect climate of different regions around the world)