Giant Brown Cloud Storm over Asia (NASA)

The chemical equator term and concept was coined in 2008 when researchers from

University of York , mottoeng = On the threshold of wisdom , established = , type = Public research university , endowment = £8.0 million , budget = £403.6 million , chancellor = Heather Melville , vice_chancellor = Charlie Jeffery , students ...

discovered a distinct divide between the polluted air and

haze Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification ...

over

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

from the largely uncontaminated atmosphere over Australia. This divide is distinguishable by a rapid increase in atmospheric levels of

carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

and other pollutants from the

Tropical Warm Pool The Tropical Warm Pool (TWP) or Indo-Pacific Warm Pool is a mass of ocean water located in the western Pacific Ocean and eastern Indian Ocean which consistently exhibits the highest water temperatures over the largest expanse of the Earth's surfac ...

region northward. The divide of the

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. ...

of the northern hemisphere from the atmosphere of the southern hemisphere is different from that of the Intertropical Convergence Zone.University of York, 2008, 'Chemical Equator' Discovery Will Aid Pollution Mapping: Science Daily: https://www.sciencedaily.com/releases/2008/09/080923091339.htm (accessed November 2021).

Discovery

Scientists at the University of York's Department of Chemistry conducted the first research that supported the concept of a 50 km wide chemical equator by comparing concentrations of atmospheric pollutants in both sides. They observed that the atmospheric boundary, where drastic and quick changes in pollutants occurred, was well north of the Intertropical Convergence Zone, which was previously thought to be the only chemical atmospheric boundary. This discovery is also the first observance of meteorological and chemical boundaries between air masses not being the same, though correlated.

Causes

Biomass Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms biom ...

burning within this region, particularly from

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

, is responsible for the polluted air which is uplifted by convection and dispersed into the atmosphere over the Western Pacific. This convection is in contrast to the clean ocean air that is advected by cyclones over Northern Australia.

Greenhouse gases A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (), carbon dioxide (), meth ...

are produced at high rates in Southeast Asia due to the less developed burning conditions, large population, and fast population growth. The soluble pollutants are mostly removed during the summer by

monsoons A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscill ...

and winds but during winter these pollutants are more present in the atmosphere, making the divide more definite. Storm systems in the

may also increase the influence of the atmospheric pollutants by acting as a pump that lifts polluted air higher up in the atmosphere where it will remain suspended for a longer period of time, as well as helping to spread it.

References

{{reflist Tropical meteorology Atmospheric dynamics Southeast Asian haze

Discovery

Causes

See also

References