The cloud detectives
8 Jun 2005 by Evoluted New Media
A cloud detection system developed by scientists at the Leicester Earth Observation Science Group could lead to a better understanding of greenhouse gases and how human activities affect them.
In an age where the environment is becoming a politically pressing issue, more emphasis is being put on scientists to find out exactly what damage is being caused and how to stop it.
But is human activity responsible for environmental change? Tim Barnett from the Scripps Institution of Oceanography said: "Evidence, based on computer models and observations in the field, is so strong that it should put an end to any debate about whether humanity is causing global warming."
A cloud detection system developed by scientists at the Leicester Earth Observation Science Group could lead to a better understanding of greenhouse gases and how human activities affect them.
The team use an atmospheric instrument onboard the ENVISAT satellite to study profiles of greenhouse gases in the atmosphere.
As ENVISAT orbits the Earth every 100 minutes, the team can create a “signature” of the various gases. However, certain regions of the atmosphere have high cloud cover that can result in inaccurate readings.
To overcome this the team developed a cloud detection scheme that identifies cloud-free data, so that ‘decontaminated’ ozone information can be used to study key regions of the atmosphere.
The team has already found increased ozone levels over equatorial Africa in a region of the atmosphere called the Upper Troposphere. Postgraduate research student Harjinder Sembhi explains: “Ozone above 20km acts as a protective shield from harmful ultraviolet radiation. However, in the troposphere it is a greenhouse gas and has the ability to affect the concentrations of other important greenhouse gases in this region. It is therefore essential to study the distribution of these gases in the tropical atmosphere to help understand their impact on the global atmosphere and climate.”
