CHAPTER 8- Air mass Flashcards by Jennifer Boone

Because there is no vertical motion, smoke & dust are concentrated in the lower layers. They can bring anything from scorching heat to bone-chilling cold depending on the type of air mass. This air mass does affect the British Isles, and it can bring very cold, wet, and snowy weather.

This typically occurs in a high pressure system with light wind. The areas where air masses develop are called source regions. Air masses over warm surfaces usually develop faster than those over colder surfaces because there is weaker turbulence in the stable air over the cold surface. When air masses shift from their source regions, they change over time due to the surfaces and terrain over which the air masses flow.

Was suggested by the Bjerkneses because the collisions of two air masses reminded them of a battlefront during a military operation. Fronts develop when two air masses with different temperatures and, in most cases, different moisture contents come into contact with each other. The result depends on the relative temperature and moisture content of the two air masses and the relative movement of the two masses. By convention, operational weather forecasters place fronts just on the warm side of the temperature gradient. In other words, a front lies just on the warm side of the narrow ribbon of tightly packed isotherms that mark the boundary between the two contrasting air masses. Although fronts can indeed be located on maps that do not have isotherms plotted, it sure helps to have them when looking for fronts.

The former is called a cold-type occluded front whereas the latter is a warm-type occluded front. The development of an occluded front is accompanied by the formation of clouds and, in most cases, by steady and moderate precipitation. An occluded front is shown on a weather map with a solid line that contains, alternatively, both triangles and half circles on the same side of the line. Air masses form when a body of air comes to rest over an area large enough for it to take on the temperature and humidity of the land or water below it. Certain locations on the earth’s surface possess the topographical characteristics that favor the development of air masses.

February 13–17, 2021 North American winter storm resulted in blackouts for over 10 million people in the U.S. and Mexico, most notably the 2021 Texas power crisis. The Iran Blizzard of February 1972 is the deadliest blizzard in history (every hear of it? It’s time you did!). In a week southern Iran received almost 8 m of snow, completely burying several villages and killing all the residents. One of the consequences of climate change appears to be an increase in the frequency and severity of hurricanes, incurring greater costs and new building guidelines.

Tropical air masses form within 25 degrees latitude of the equator. These masses, abbreviated with a “T,” can develop over land or water. Source regions include the Gulf of Mexico, southwestern United States and northern Mexico.

But on the leeward side air is descending, warming, and not condensing. Air masses are large, uniform bodies of air, with no major differences in temperature, wind and humidity. All of the air in an air mass is more-or-less the same temperature, pressure, and relative humidity. Vertical movements can be induced in how to get fishing pole genshin the air masses by geography, cyclones, and anticyclones – called mechanical or dynamic. They need an extensive and uniform area and an an of general stagnation or low atmospheric circulation. The movement of air masses across the Earth’s surface is an important component of the weather that develops in an area.