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

University of York The University of York (abbreviated as or ''York'' for Post-nominal letters, post-nominals) is a public Collegiate university, collegiate research university in York, England. Established in 1963, the university has expanded to more than thir ...

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 classificati ...

over

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

from the largely uncontaminated atmosphere over

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. This divide is distinguishable by a rapid increase in atmospheric levels of

carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and 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 region northward. The divide of the

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

of the

northern hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

from the atmosphere of the southern hemisphere is different from that of the

Intertropical Convergence Zone The Intertropical Convergence Zone (ITCZ , or ICZ), known by sailors as the doldrums or the calms because of its monotonous windless weather, is the area where the northeast and the southeast trade winds converge. It encircles Earth near the t ...

.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

, 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 a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

burning within this region, particularly from

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

, 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 Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...

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 oscil ...

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