ATOC 181 Lecture Notes - Lecture 9: Anemometer, Sodar, Lidar

• School: McGill University
• Department: Atmospheric & Oceanic Sciences
• Course: ATOC 181
• Professor: Andreas Zuend

Document Summary

Chapter 9 winds at different scales: small and local. - topics: 1) scales of atmospheric motions: microscale and local wind systems, turbulence and surface friction, influence of obstacles and topography; 3) thermal circulations at different scales: land & sea breezes, mountain & valley breezes, chinook, monsoon; 4) measuring wind velocity and direction: local weather station measurements, vertical wind profiles. Coriolis force - not important for microscale, but for macroscale. This two air collide even if one (air and its molecules) is stationary. Mechanical generation: regions of strong wind shear (= a. Forced convection = eddy motions created by obstructions to the wind: friction at the earth"s surface; flow past bluff bodies (buildings, mountain peaks); Mechanical turbulence creates a drag on the air-flow > that caused by molecular viscosity. The frictional drag of the ground normally decreases as moving away from the surface / higher in altitude increased wind speed;