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
Type 079-class landing ship 1972 to January 1977 revealed the performance was somewhat satisfactory, but the speed was slow and the ability to operate in bad weather condition is poor. Work immediately begun on redesign named as Type 079II-class, while the first unit subsequently became named as Type 079I. A total of 31 were built, including the conversion of the sole Type 079I to Type 079II standard. 26 were completed by Guangzhou Shipyard International, and 4 were completed by Xiamen Shipyard. Like its predecessor Type 079I, the Type 079II was also designed by 708th Research Institute. The main difference between 079I and 079II is