But the weather-climate dichotomy paints an incomplete picture – one that may be complicating efforts to untangle natural variations in climate from man-made effects, according to McGill University physics professor Shaun Lovejoy.
In a paper published recently in the journal Eos, Transactions, American Geophysical Union, and in a forthcoming book, Lovejoy argues that statistical analysis shows there is a period between short-term weather and long-term climate that should be recognized as distinct.
Using the three-part atmospheric regime also makes the challenge of climate modeling more precise, and could open up a new set of approaches for modeling and predicting the climate, Lovejoy says.
Lovejoy used a new kind of "fluctuation analysis" to show that there are three atmospheric regimes, each with different types of variability. Between the weather (periods less than 10 days) and the climate (periods longer than about 30 to 100 years), there is an intermediate "macroweather" regime. A graphic representation makes the case intuitively clear.
The accompanying chart shows examples from weather (one-hour resolution, bottom), macroweather (20 days, middle) and climate (one century, top). The daily and annual cycles were removed and 720 consecutive points from each resolution are shown so that the differences in the characters of each regime are visually obvious.
At the bottom, the weather curve "wanders" up or down in a path resembling a drunkard's walk. In the middle, the macroweather curve has a markedly different character: upward fluctuations are typically followed by nearly cancelling downward ones. "The longer the period over which we average it, the smaller the variations become," Lovejoy says.
By contrast, the century scale climate curve (top) displays again a weather-like, wandering variability. (While this plot shows temperatures, other atmospheric fields – including wind, humidity and precipitation -- are similar.)
Although the ultimate implications of macroweather may not be known for some time, a basic change in our understanding of what climate is will surely have repercussions, Lovejoy notes.
"Macroweather clarifies the distinction between natural and anthropogenic types of variability and allows us to separate the two with more confidence."The old saying that "climate is what you expect, weather is what you get," also needs to be reconsidered, he adds. "Macroweather is what we expect."
Chris Chipello | EurekAlert!
Theory of the strong interaction verified
27.03.2015 | Forschungszentrum Juelich
Dark matter even darker than once thought
27.03.2015 | ESA/Hubble Information Centre
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
27.03.2015 | Agricultural and Forestry Science
27.03.2015 | Materials Sciences
27.03.2015 | Ecology, The Environment and Conservation