Rain dust or snow dust, traditionally known as muddy rain, red rain, or coloured rain, is a variety of rain (or any other form of precipitation) which contains enough mineral dust, from soils (particularly from deserts), for the dust to be visible without using a microscope.
The rain dust phenomenon was studied by Italian scientist Giuseppe Maria Giovene (1753–1837), who managed to correctly explain the phenomenon as early as 1803. On 7 March 1803, rain dust fell over Southern Italy's region Apulia. At that time, people believed that the rain was caused by the explosions of Italy's volcanoes Mount Vesuvius or Etna, or that it was due to the transport of matter coming from the sea floor and raised by vapor. Giuseppe Maria Giovene related the phenomenon to the wind which occurred prior to the rain event, and he came to the conclusion that the sand had come from Africa and that it had been pushed by the wind coming from south-east. [1] [2]
Rain dust is common in the Western and Southern Mediterranean, where the dust supply comes from the atmospheric depressions going through the northern part of North Africa. The main sources of desert dust reach the Iberian Peninsula and the Balearic Islands in the form of dust transported by wind or rain from the Sahara, Atlas Mountains in Morocco and Central Algeria. [3]
Mud rains are relatively frequent and had been increasing in early 1990s in the Mediterranean Basin. [4]
It also occurs in arid desert regions of North America such as west Texas or Arizona. It occasionally happens in the grasslands as it did in Bexar County, Texas on March 18, 2008.
The rain dust is very alkaline. [3] Some of the large particles contain mixtures of chemicals such as sulfate and sea salt (chiefly with sodium, chlorine and magnesium). Major minerals in order of decreasing abundance are: illite, quartz, smectite, palygorskite, kaolinite, calcite, dolomite and feldspars. [3] In Majorca a study finds that the size, by volume, 89% of the particles from rain dust fraction corresponded to silt (between 0.002 mm and 0.063 mm) and that there was virtually no clay sized particles (less than 0.29%). [5]
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Rain dust is the most common cause of blood rain.
Red rain is however not always rain dust, see for example the Red rain in Kerala.
Desertification is a type of gradual land degradation of fertile land into arid desert due to a combination of natural processes and human activities. This spread of arid areas is caused by a variety of factors, such as overexploitation of soil as a result of human activity and the effects of climate change. Geographic areas most affected are located in Africa, Asia and parts of South America. Drylands occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people. Effects of desertification include sand and dust storms, food insecurity, and poverty.
South Korea is located in East Asia, on the southern portion of the Korean Peninsula located out from the far east of the Asian landmass. The only country with a land border to South Korea is North Korea, lying to the north with 238 kilometres (148 mi) of the border running along the Korean Demilitarized Zone. South Korea is mostly surrounded by water and has 2,413 kilometres (1,499 mi) of coast line along three seas; to the west is the Yellow Sea, to the south is the East China Sea, and to the east is the Sea of Japan. Geographically, South Korea's landmass is approximately 100,032 square kilometres (38,623 sq mi). 290 square kilometres (110 sq mi) of South Korea are occupied by water. The approximate coordinates are 37° North, 128° East.
Sudan is located in Northeast Africa. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the southwest, Chad to the west and Libya to the northwest. Sudan is the third largest country in Africa, after Algeria and the Democratic Republic of the Congo. It was the largest country on the continent until South Sudan split off from it in 2011.
A dust storm, also called a sandstorm, is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Fine particles are transported by saltation and suspension, a process that moves soil from one place and deposits it in another.
Niter or nitre is the mineral form of potassium nitrate, KNO3. It is a soft, white, highly soluble mineral found primarily in arid climates or cave deposits.
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts.
The Kerala red rain phenomenon was a blood rain event that occurred in Wayanad district of southern Indian state Kerala on Monday, 15 July 1957 and the colour subsequently turned yellow and also 25 July to 23 September 2001, when heavy downpours of red-coloured rain fell sporadically in Kerala, staining clothes pink. Yellow, green and black rain was also reported. Coloured rain was also reported in Kerala in 1896 and several times since, most recently in June 2012, and from 15 November 2012 to 27 December 2012 in eastern and north-central provinces of Sri Lanka.
Alkaline precipitation occurs due to natural and anthropogenic causes. It happens when minerals, such as calcium, aluminum, or magnesium combine with other minerals to form alkaline residues that are emitted into the atmosphere, absorbed by water droplets in clouds, and eventually fall as rain. Aquatic environments are especially impacted by alkaline precipitation. Because alkaline precipitation can be harmful to the environment, it is important to utilize various methods such as air pollution control, solidification and stabilization, and remediation to manage it.
Alkali, or Alkaline, soils are clay soils with high pH, a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate, which causes the soil to swell and difficult to clarify/settle. They derive their name from the alkali metal group of elements, to which sodium belongs, and which can induce basicity. Sometimes these soils are also referred to as alkaline sodic soils. Alkaline soils are basic, but not all basic soils are alkaline.
Yucca Flat is a closed desert drainage basin, one of four major nuclear test regions within the Nevada Test Site (NTS), and is divided into nine test sections: Areas 1 through 4 and 6 through 10. Yucca Flat is located at the eastern edge of NTS, about ten miles (16 km) north of Frenchman Flat, and 65 miles (105 km) from Las Vegas, Nevada. Yucca Flat was the site for 739 nuclear tests – nearly four of every five tests carried out at the NTS.
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location.
Blood rain or red rain is a phenomenon in which blood is perceived to fall from the sky in the form of rain. Cases have been recorded since Homer's Iliad, composed approximately 8th century BC, and are widespread. Before the 17th century it was generally believed that the rain was actually blood. Literature mirrors cult practice, in which the appearance of blood rain was considered a bad omen. It was used as a tool foreshadowing events, but while some of these may be literary devices, some occurrences are historic. There is now a scientific consensus that the blood rain phenomenon is caused by aerial spores of green microalgae Trentepohlia annulata.
Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolonged weathering of the underlying parent rock, usually when there are conditions of high temperatures and heavy rainfall with alternate wet and dry periods. The process of formation is called laterization. Tropical weathering is a prolonged process of chemical weathering which produces a wide variety in the thickness, grade, chemistry and ore mineralogy of the resulting soils. The majority of the land area containing laterites is between the tropics of Cancer and Capricorn.
The composition of Mars covers the branch of the geology of Mars that describes the make-up of the planet Mars.
Martian regolith simulant is a terrestrial material that is used to simulate the chemical and mechanical properties of Martian regolith for research, experiments and prototype testing of activities related to Martian regolith such as dust mitigation of transportation equipment, advanced life support systems and in-situ resource utilization.
Dan Hardy Yaalon was an Israeli pedologist and soil scientist, who contributed to the fields of arid and Mediterranean pedology and paleopedology, as well as the history, sociology, and philosophy of soil science. Through a research career spanning over six decades (1950–2014), Yaalon was an active member of the International Union for Quaternary Research (INQUA) and the International Soil Science Society. He was awarded the Sarton Medal for his contribution to the history of science, and the Dokuchaev Award.
Giuseppe Maria Giovene was an Italian archpriest, naturalist, agronomist, geologist, meteorologist, entomologist and ichthyologist. He is best known for his studies on the "nitrosity" of Pulo di Molfetta, which made him famous abroad, so as to be cited and appreciated by many Italian and foreign scholars, including Eberhard August Wilhelm von Zimmermann in a French publication.
The Phoenix Vernal Pools are located in Fair Oaks, California, a suburb of Sacramento city around 20 miles east of the city of Sacramento and north of highway 50. This land consists of seasonally inundated wetlands that form after winter rains. The climate type of Phoenix Vernal Pools is classified as Mediterranean, receiving 24 in (610 mm) of rain per year. The rainwater percolates into the soil until it reaches an impermeable hardpan that causes an elevated water table, forming the vernal pools. The Phoenix Vernal Pool ecosystem is relatively unique as is supports many species of fauna and flora endemic to vernal pools.
The soil matrix is the solid phase of soils, and comprise the solid particles that make up soils. Soil particles can be classified by their chemical composition (mineralogy) as well as their size. The particle size distribution of a soil, its texture, determines many of the properties of that soil, in particular hydraulic conductivity and water potential, but the mineralogy of those particles can strongly modify those properties. The mineralogy of the finest soil particles, clay, is especially important.
Saharan dust is an aeolian mineral dust from the Sahara desert, the largest hot desert in the world. The desert spans just over 9 million square kilometers, from the Atlantic Ocean to the Red Sea, from the Mediterranean sea to the Niger River valley and the Sudan region in the south.
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