Their findings show for the first time that the chemical and meteorological boundaries between the two air masses are not necessarily the same.
Observations of the novel boundary will provide important clues to help scientists to model simulations of the movement of pollutants in the atmosphere more accurately, and to assess the impact of pollution on climate, the researchers say.
A scientific paper about the chemical equator is to be published in the Journal of Geophysical Research - Atmospheres, a publication of the American Geophysical Union (AGU).
Scientists had previously thought that a meteorological feature-- the Intertropical Convergence Zone (ITCZ)--formed the boundary between the polluted air of the Northern Hemisphere and the clearer air of the Southern Hemisphere. The ITCZ is a cloudy region circling the globe where the trade winds from each hemisphere meet. It is characterized by rapid vertical uplift and heavy rainfall, and acts as a meteorological barrier to pollutant transport between the hemispheres.
But, in cloudless Western Pacific skies well to the north of the ITCZ, Jacqueline Hamilton of York University and her colleagues found evidence for an atmospheric chemical equator around 50 kilometers (31 miles) wide.
Across that newfound borderline, air quality differed dramatically. For instance, carbon monoxide, a tracer of combustion, increased from 40 parts per billion to the south, to 160 parts per billion in the north. The difference in pollutant levels was increased by extensive forest fires to the north of the boundary and very clean air south of the chemical equator being pulled north from the Southern Indian Ocean by a land based cyclone in northern Australia.
The scientists discovered evidence of the chemical equator using sensors on a specially equipped airplane during a series of flights north of Darwin, a city on the northern coast of Australia. At the time, the ITCZ was situated well to the south over central Australia.
Researchers from the universities of York, Manchester, Cambridge, Leicester, and Leeds--all in the United Kingdom--collaborated in the study.
"The shallow waters of the Western Pacific, known as the Tropical Warm Pool, have some of highest sea surface temperatures in the world, which result in the region's weather being dominated by storm systems," says Hamilton, lead author of the scientific paper. "The position of the chemical equator was to the south of this stormy region."
"This means that these powerful storms may act as pumps, lifting highly polluted air from the surface to high in the atmosphere where pollutants will remain longer and may have a global influence," Hamilton notes. "To improve global simulations of pollutant transport, it is vital to know when the chemical and meteorological boundaries are in different locations."
This research was funded by the United Kingdom's Natural Environment Research Council (NERC) as part of the ACTIVE project (Aerosol and Chemical Transport in Tropical Convection).
Other partners include the Australian Bureau of Meteorology and Flinders University in Adelaide, Australia. Flights were carried out onboard the NERC Airborne Research and Survey Facility Dornier 228 aircraft.Title:
Grant Allen, Geraint Vaughan, Keith N. Bower, Michael J. Flynn, and Jonathan Crosier: School of Earth, Atmospheric and Environmental Science, University of Manchester, Manchester, United Kingdom;
Glenn D. Carver and Neil R. P. Harris: Chemistry Department, University of Cambridge, Cambridge, United Kingdom;
Robert J. Parker and John J. Remedios: Earth Observation Science, Space Research Centre, Department of Physics &Astronomy, University of Leicester, Leicester, UK.
Nigel A.D. Richards: Institute for Atmospheric Science, School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds, United Kingdom.Citation:
firstname.lastname@example.orgAlastair Lewis: Professor, Department of Chemistry, University of York; Composition Director, National Centre for Atmospheric Science; phone: +44 (0)1904 432522
email: email@example.comGeraint Vaughan: Professor, School of Earth, Atmospheric and Environmental Sciences, University of Manchester; Weather Director, National Centre for Atmospheric Science; phone: +44 (0)
161 306 3931, email: firstname.lastname@example.org
Peter Weiss | American Geophysical Union
Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America
Ice stream draining Greenland Ice Sheet sensitive to changes over past 45,000 years
14.05.2018 | Oregon State University
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology