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 NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>