Weather map motion. Two-dimensional streamlines based on wind speeds at various levels show areas of convergence and divergence in the wind field, which are helpful in determining the location of features within the wind pattern. A popular type of surface weather map is the surface weather analysis, which plots isobars to depict areas of high pressure and low pressure. Cloud codes are translated into symbols and plotted on these maps along with other meteorological data that are included in synoptic reports sent by professionally trained observers. The use of weather charts in a modern sense began in the middle portion of the
Zero-profit condition Zero-profit condition In economic competition theory, the zero-profit condition describes the condition that occurs when an industry or type of business has an extremely low (near-zero) cost of entry. In this situation, many people tend to join the industry, seeing the opportunity to make money, until there is no more money to make (supply exceeds demand); the large amount of competition limits each person's share of the market, as well as their ability to pursue a large profit margin. This would represent a situation of almost perfect competition. For instance, despite the real estate boom of the mid-2000s, the incomes