By the end of this chapter, you should be able to:
- identify regions of convergence, divergence, positive vorticity, and negative vorticity on a weather map
- calculate the strength of the different flow types from observations
- relate vertical motion to horizontal convergence and divergence
The study of kinematics provides a physical and quantitative description of our atmospheric motion, while the study of dynamics provides the physical and quantitative cause-and-effect for this motion. This lesson discusses kinematics. When we look at weather in motion from a satellite, we see very complicated swirls and stretching that evolve over time. We can see the same types of motions on a much smaller scale by observing swirling leaves. These complex motions can be ascribed to combinations of just five different types of atmospheric motion. Quantifying these motions with mathematics, without assigning a cause to the motion, is the focus of this lesson on kinematics.
Global composite infrared satellite image for 13 June 2015. The air motion is indicated by the infrared radiation from clouds, which were formed from vertical air motion resulting in cooling. Credit: NASA Global Hydrology and Climate Center
Thumbnail: Water vapor in the atmosphere over North America showing the behavior of different air parcels as they interact. (Public Domain: NOAA)