Online, www.eumetrain.org
Wave phenomena can be found at any level of the atmosphere and can be detected by infrared, visible and water vapour channels. Their regular pattern may extend over hundreds or thousands of kilometres.
But, why is it so important to locate atmospheric waves?
Waves are vertically oscillating air masses which means aircraft passing through such regions are subject to strong vertical accelerations or turbulence. Turbulence is a major threat to aircraft and passengers. Past aviation accidents have shown the vulnerability of planes which entered a region with severe turbulence caused by lee waves.
The module starts with a retrospect on the accident of BOAC Flight 911 in 1966, which illustrates the danger of atmospheric mountain waves. In the subsequent chapters, the reader learns more about the characteristics of lee waves in different spectral channels, and on the physical mechanisms behind atmospheric wave phenomena. One chapter is dedicated to the most prominent wave producing wind in Europe: the Foehn.
Gravity waves over the ocean, their origins and development in time are explained. The final chapter is on the Kármán vortex street, an atmospheric wave phenomenon but not a gravity wave. There are test exercises at the end of each chapter.