Unveiling the World of Dust: Origins, Movements, and Historical Perspectives
Dust, a fine-grained sediment, originates mainly from arid regions like deserts, with the Sahara being a major source. Carried by winds over vast distances, dust plays a crucial role in shaping landscapes and climate. The amount of dust in the atmosphere has fluctuated throughout Earth's history, with glacial periods marked by increased dust due to glacial activities. Explore the intriguing world of dust and its impact on our planet.
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Whats the deal with dust? Dust is fine-grained sediment that erodes from rocks on the land, is carried into the atmosphere, and then settles back onto the land and into the ocean. At any time, there is between 17-20 million tons of dust in the atmosphere. Some places end up with more dust deposits than others. Dust deposits with current climate conditions
Where does dust come from? Areas with dry climates make lots of dust. Most of the dust in the atmosphere comes from deserts. The Sahara Desert in northern Africa produces far more atmospheric dust than any other region in the world. Deserts of the World
Where does dust come from? Areas with dry climates make lots of dust. Most of the dust in the atmosphere comes from deserts. The Sahara Desert in northern Africa produces far more atmospheric dust than any other region in the world. Deserts and dust deposits with current climate conditions
What moves the dust around? Dust is carried around the world by winds that blow in predictable patterns. Wind can carry dust thousands of miles from its source. Winds
What moves the dust around? Dust is carried around the world by winds that blow in predictable patterns. Wind can carry dust thousands of miles from its source. Winds and dust deposits with current climate conditions
Has it always been this dusty? The amount of dust in the atmosphere has changed throughout Earth s history. This map shows dust deposits from the Last Glacial Maximum - which was approximately 22,000 years ago - when the climate was much cooler. Dust deposits during the Last Glacial Maximum (LGM)
Has it always been this dusty? Compared to the amount of dust today (left), there was much more dust during the last glacial period (right). Glacial periods are dustier because moving glaciers and ice sheets grind bedrock into fine dust, which blows away in the wind. Dust deposits with current climate conditions Dust deposits during the Last Glacial Maximum (LGM)
Are certain times of the year dustier than others? The amount of dust in the air changes seasonally in response to changes in temperature and wind patterns. In the Atlantic Ocean, the dustiest months are from June-August.
How does dust affect Earths climate? Dust that settles into the ocean adds iron and other nutrients to the water, which helps phytoplankton to grow. Phytoplankton take carbon dioxide out of the atmosphere, which helps cool the climate. Phytoplankton remove about 10 gigatons of carbon from the atmosphere each year. Dust in the air also affects the climate by scattering light and absorbing energy from the Sun. Tiny particles suspended in the air are called aerosols. The winds carry large amounts of dust aerosols from central Asia into the North Pacific Ocean during April and May of each year. Where chlorophyll levels are higher, phytoplankton are abundant (shown as bright areas in the ocean). Large amounts of dust entering the ocean from Asia during April and May allow phytoplankton populations to grow.
How do we know so much about dust? Scientists study the rocks that make dust in the Junggar Basin, Xinjiang Province, China, to learn about the past climate of Eastern Asia. The geologist uses a Jacob staff to measure the thickness of sedimentary rock layers.
Credits Dust Tales was created by the UCAR Center for Science Education as part of the educational activities supporting the NSF funded project PIRE: DUST stimulated draw-down of atmospheric CO2 as a trigger for Northern Hemisphere Glaciation (Award #1545859) Dust deposition data maps sourced from: Mahowald, N. M., D. R. Muhs, S. Levis, P. J. Rasch, M. Yoshioka, C. S. Zender, and C. Luo (2006), Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates, J. Geophys.Res., 111, D10202, doi:10.1029/2005JD006653. Aerosols and Chlorophyll data maps from NASA Earth Observations: https://neo.gsfc.nasa.gov/view.php?datasetId=MODAL2_M_AER_OD&year=2018 https://neo.gsfc.nasa.gov/view.php?datasetId=MY1DMM_CHLORA&date=2018-12-01 A Dusty Journey: https://earthobservatory.nasa.gov/images/146122/a-dusty-journey Biome Map: Deserts of the World: https://commons.wikimedia.org/wiki/File:Biome_map_13.svg Prevailing winds: https://en.wikipedia.org/wiki/Prevailing_winds#/media/File:Map_prevailing_winds_on_earth.png
