Dutch research into fair-weather clouds important in climate predictions

Dec 08, 2008
Today, with the help of better observational methods and more powerful computers, we can get a much nicer picture of how clouds "work." Credit: TU Delft

Research at the Delft University of Technology (The Netherlands) has led to better understanding of clouds, the unknown quantity in current climate models. The Delft researcher Thijs Heus has tackled this issue with a combination of detailed computer simulations and airplane measurements. He charted data including cloud speed, temperature and the 'life span' of clouds to arrive at new observations.

The behaviour of clouds is the great unknown quantity in current climate models. To make reliable predictions on climate change, more knowledge about clouds is thus essential. Heus explains, 'What we call fair-weather clouds have posed one of the biggest challenges in atmospheric science for decades. For accurate representation of clouds in weather and climate models, it is crucial to have a solid understanding of the interaction between clouds and the environment. Today, with the help of better observational methods and more powerful computers, we can get a much nicer picture of how it works.'

Heus continues, 'A cloud is normally described as an entity in which air rises. All around the cloud, air sinks downward in compensation for the upward movement.

'We demonstrated that air far away from the cloud on average displaces very little. The biggest amount of compensatory downward flow occurs immediately surrounding the cloud, in a ring of sinking air. This ring results because cloud air mixes with the surroundings, causing the cloud water to evaporate, air to cool, and thereby sink. The interaction between the cloud and its environment as such occurs indirectly, through the buffer zone of the ring. This buffer zone has not yet been incorporated into climate models until now.

'The ring is principally created by horizontal mixing. We showed that whatever happens on the cloud top has little influence on the underlying layers.'

A cloud's behaviour is likewise affected over time by this same horizontal mixing; the air in a cloud appears not to rise continuously, but rather in bubble-shaped form. Using visualizations in a Virtual Reality-environment, Heus could reliably research this tendency for the first time.

The Royal Netherlands Meteorological Institute (KNMI), Heus' current employer, and other scientific institutes have already expressed interest in the results of his study.

Source: Delft University of Technology

Explore further: Sculpting tropical peaks

add to favorites email to friend print save as pdf

Related Stories

Volcano expert comments on Japan eruption

2 hours ago

Loÿc Vanderkluysen, PhD, who recently joined Drexel as an assistant professor in Department of Biodiversity, Earth and Environmental Science in the College of Arts and Sciences, returned Friday from fieldwork ...

Bats may be mistaking wind turbines for trees

Sep 30, 2014

Certain bats may be approaching wind turbines after mistaking them for trees, according to a study to be published in the Proceedings of the National Academy of Sciences.

NREL software tool a boon for wind industry

Sep 30, 2014

Wind energy is blowing away skeptics—it's so close to achieving cost parity with fossil fuels that just a little extra efficiency is all that is likely needed to push it into the mainstream and past the ...

New technology tracks tiniest pollutants in real time

Sep 26, 2014

Researchers may soon have a better idea of how tiny particles of pollution are formed in the atmosphere. These particles, called aerosols, or particulate matter (PM), are hazardous to human health and contribute ...

Recommended for you

Sculpting tropical peaks

1 hour ago

Tropical mountain ranges erode quickly, as heavy year-round rains feed raging rivers and trigger huge, fast-moving landslides. Rapid erosion produces rugged terrain, with steep rivers running through deep ...

NASA's HS3 looks Hurricane Edouard in the eye

15 hours ago

NASA and NOAA scientists participating in NASA's Hurricane and Severe Storms Sentinel (HS3) mission used their expert skills, combined with a bit of serendipity on Sept. 17, 2014, to guide the remotely piloted ...

Tropical Storm Rachel dwarfed by developing system 90E

20 hours ago

Tropical Storm Rachel is spinning down west of Mexico's Baja California, and another tropical low pressure area developing off the coast of southwestern Mexico dwarfs the tropical storm. NOAA's GOES-West ...

NASA ocean data shows 'climate dance' of plankton

23 hours ago

The greens and blues of the ocean color from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton—microscopic aquatic plants ...

User comments : 0