Climates semiarid and arid

Arid and semiarid climates
Arid climates

We identified two typical arid northern Mexico, and on the Pacific coast of South America between 5 and 30 th latitude.
-Characteristics of the climate.The two typical arid zones are associated with tropical latitudes and are determined by the existence of high pressure over the Pacific Ocean, which generate and dry downdrafts.
The desert ofnorthern Mexico's table. With less than 400 mm annual rainfall, the desert has a marked continental, which is due to the obstacle of the two longitudinal ranges (Sierra Madre Oriental and Occidental) withrespect to the maritime influence. For this reason, the annual thermal amplitudes are accentuated north to reach over 20 ° C. Winters, therefore, are rigorous because of the outbreak of cold air thatcomes without hindrance from the American desert.
The arid Mexican desert due to the wind direction and temperature, rather cold, the Pacific Ocean at this latitude. The highest temperatures in Mexicoare recorded in the lowlands of the north end of the desert. In Colorado River in the Gulf of California reaches approximately 45 ° C in the hottest days of summer.
The Peruvian-Chilean desert.Hiperaridez is famous for its being in some sectors the most absolute of the Earth, by the total lack of rain and water sources (Atacama Desert). Factor in this very dry (46 mm per year in Lima, 2.1 mmper year in Iquique) is the influence of the cold Humboldt current, together with the belt of high pressure, inhibits rainfall. As a result of this stream, along the coast is a belt of high humiditycharacterized by "low fog" (desert sea). Thermal averages are not exaggerated (Lima, 19.3 ° C; Iquique 17.5 ° C), whereas the differences between day and night are remarkable. The presence of the coldmakes the Peruvian-Chilean desert to be tropical, is surprisingly cool in summer and low annual oscillation. His remarkable influence is evident in the great uniformity of the average temperatures...