Aurora Nephelometer

Climate change (global warming and global dimming) is impacting the entire planet on which we live. Many governments throughout the world have realized the size and complexity of the problem and are beginning to take decisive action to ameliorate the effects of global warming. A key component of taking action is to understand:

• What is happening?
• Why is it happening?
• How is it happening?

Global warming/global dimming have many interrelated factors that influence the type, rate and direction of changes that can affect the earth’s radiation balance.

The Earth is warmed principally by the sun’s radiation which enters the atmosphere. Not all the radiation penetrates the atmosphere as some is scattered back into space. The amount of back-scattering into space alters the amount of energy that is absorbed into the atmosphere, this is known as global dimming (see figure below). Measuring the amount of backscattering of this light provides valuable information on the change in the earth’s radiation balance and how different activities (artificial and anthropogenic) can affect this delicately balanced system.

Global dimming has, by all accounts, reduced the radiation reaching the earth's surface and thus cooled the planets heating. This is explained best in the folowing transcript at www.pbs.org. Measuring the effect global dimming throughout various parts of the world will help dramatically in predicting global temperature rises and the effect these will have on climate change.

The Aurora 3000 Three wavelength nephelometer with backscatter is an ideal instrument for determining the backscatter of radiation back into space. An extension of this instrument is the Aurora 4000 polar nephelometer which can measure scatter in specific segments, giving a much more detailed understanding of particulate scattering.