Desert biomes are distinctive terrestrial ecosystems characterized by their extreme aridity, meaning they receive very low levels of precipitation. This lack of water shapes the unique plant and animal life that can survive in these environments. Understanding where these dry regions are situated across the planet helps to explain the patterns of global biodiversity and climate. This article explores the geographical distribution of these remarkable biomes.
Global Overview of Desert Locations
Deserts are found across various continents, often concentrated in specific latitudinal bands. Many of the world’s largest deserts are located around 30 degrees north and 30 degrees south of the equator. This global pattern is influenced by atmospheric circulation patterns that create dry conditions in these zones. Major desert biomes are present on nearly every continent, including Africa, Asia, Australia, North America, South America, and even the polar regions.
These arid landscapes vary greatly in size and specific climatic conditions. While some deserts are expansive, covering vast stretches of land, others are comparatively smaller. Their widespread presence highlights the diverse set of geographical and atmospheric factors that can lead to extreme dryness in different parts of the world.
Where Hot Deserts Are Found
Hot deserts are primarily located in subtropical regions, characterized by high daytime temperatures and significant fluctuations. The Sahara Desert, the largest hot desert, spans across much of North Africa, covering countries like Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, and Tunisia. East of the Sahara, the Arabian Desert dominates the Arabian Peninsula in the Middle East, extending through Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, and Jordan.
In Australia, a significant portion of the continent’s interior is covered by hot deserts, including the Great Victoria Desert, Gibson Desert, and Simpson Desert. Southern Africa hosts the Kalahari Desert, which spans Botswana, Namibia, and South Africa, and the coastal Namib Desert, primarily in Namibia. North America features the Sonoran Desert, found in parts of Arizona and California in the United States, and Sonora, Mexico, alongside the Mojave Desert in California, Nevada, Arizona, and Utah. South America’s Atacama Desert, one of the driest places on Earth, is located along the Pacific coast of Chile and Peru.
Where Cold Deserts Are Found
Cold deserts are arid environments, characterized by low temperatures and often receiving precipitation in the form of snow. These can be broadly divided into polar deserts and temperate cold deserts. Polar deserts encompass the vast, ice-covered regions of the Arctic and Antarctic, where precipitation is minimal and temperatures remain below freezing for most of the year. The Antarctic Polar Desert, for instance, covers nearly the entire continent of Antarctica, while the Arctic Polar Desert extends across parts of Greenland, Canada, and Russia.
Temperate cold deserts are found at higher latitudes in continental interiors, far from oceanic moisture sources. The Gobi Desert is a prominent example, stretching across large areas of Mongolia and China in Central Asia. In Western North America, the Great Basin Desert covers much of Nevada, Utah, Oregon, and Idaho, characterized by its cold winters and hot summers. South America is home to the Patagonian Desert, situated in Argentina and parts of Chile, which experiences cold, windy conditions due to its location in the rain shadow of the Andes Mountains.
Geographical Factors Influencing Desert Placement
The global distribution of deserts is shaped by geographical and atmospheric factors. A significant cause for many hot deserts is the presence of high-pressure systems, particularly the Hadley cells, which cause dry, descending air around 30 degrees north and south latitude. As this air descends, it warms and dries, inhibiting cloud formation and precipitation. This atmospheric circulation pattern largely explains the subtropical desert belts.
The rain shadow effect is another factor, where mountain ranges block moisture-laden winds. As air masses rise over mountains, they cool and release their moisture as precipitation on the windward side. By the time the air descends on the leeward side, it is dry, creating arid conditions in the rain shadow. The Andes Mountains contribute to the extreme dryness of the Atacama Desert, and the Sierra Nevada range helps create the Great Basin Desert in North America. Cold ocean currents also contribute, as they cool the air above them, stabilizing the atmosphere and preventing the formation of rain-producing clouds. The Benguela Current along southwestern Africa contributes to the aridity of the Namib Desert, and the Humboldt Current off the coast of South America influences the Atacama Desert.