Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate and pollution: a week link?

15.02.2002


Atmospheric carbon dioxide is lower at the weekend.


Mauna Loa observatory: continuous atmospheric carbon dioxide measurements since the 1950s
© NOAA/CMDL



The climate-monitoring station on Mauna Loa volcano on Hawaii, 3,400 metres above sea level, could hardly be farther away from it all. Yet even here there is no escaping the weekly rhythm of modern life. The observatory records lower concentrations of carbon dioxide in the atmosphere at the weekend than during the week.

Because there is no known natural cause of such a seven-day cycle, Randall Cerveny of Arizona State University and Kevin Coakley of the National Institute of Standards and Technology in Boulder, Colorado, propose that these observations reflect the weekday bustle and weekend lull in Hawaii’s populated regions1.


Increased traffic on Hawaii’s islands, especially in the main city Hilo, is the most likely cause. Carbon dioxide is a greenhouse gas - it absorbs and retains solar heat in the Earth’s atmosphere. Vehicles, industry and agriculture produce the gas when they burn fossil fuels. It is the main component of exhaust fumes.

Could these weekly carbon dioxide cycles cause corresponding variations in climate? The researchers point out that some climate records already show signs of such effects. Global average temperatures and regional rainfall seem to depend to a small degree on the day of the week.

The daily grind

Established in the 1950s, the Mauna Loa weather-monitoring station now takes continuous measurements of atmospheric carbon dioxide levels to help understand how human activities are changing global climate.

The Mauna Loa records show a steady rise in atmospheric carbon dioxide levels over the past few decades, modulated by an annual rise and fall owing to seasonal changes in the natural sources and sinks of the gas (caused by differences in plant growth, for instance). Cyclical changes on shorter time scales are harder to spot in the records, because they are usually much weaker than the seasonal oscillations, and masked by random variations in the data.

Cerveny and Coakley spotted the weekly cycle by calculating the average carbon dioxide levels for each day of the week, after subtracting out changes owing to the seasonal cycle and the gradual yearly rise. They find that the measurements rise to a peak on Mondays and then decline steadily to a minimum on Saturdays.

Crucially, the researchers find no such cycle in carbon dioxide records from the Amundsen-Scott South Pole Station in Antarctica, which is far from any sources of pollution. The Antarctic measurements show the same yearly trend and seasonal cycle, but there is no significant difference between average daily values.

The researchers reason that by the time carbon dioxide pollution reaches Antarctica, such short-term variations have evened out. On Hawaii, in contrast, local pollution levels seem to register almost instantly at the Mauna Loa station.

References

  1. Cerveny, R. S. & Coakley, K. J. A weekly cycle in atmospheric carbon dioxide. Geophysical Research Letters, 29, 10.1029/2001GL013952 (2002).

PHILIP BALL | © Nature News Service
Further information:
http://www.nature.com/nsu/020211/020211-10.html

More articles from Earth Sciences:

nachricht The Wadden Sea and the Elbe Studied with Zeppelin, Drones and Research Ships
19.09.2017 | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung

nachricht FotoQuest GO: Citizen science campaign targets land-use change in Austria
19.09.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>