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 Atmospheric scientists reveal the effect of sea-ice loss on Arctic warming
11.03.2019 | Institute of Atmospheric Physics, Chinese Academy of Sciences

nachricht Sensing shakes
11.03.2019 | University of Tokyo

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

Im Focus: The moiré patterns of three layers change the electronic properties of graphene

Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.

Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Researchers measure near-perfect performance in low-cost semiconductors

18.03.2019 | Power and Electrical Engineering

Nanocrystal 'factory' could revolutionize quantum dot manufacturing

18.03.2019 | Materials Sciences

Long-distance quantum information exchange -- success at the nanoscale

18.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>