Clouds have a profound effect on the climate, but we know
surprisingly little about how they form. Erika Sundén,
researcher at the University of Gothenburg, Sweden, has studied
how extremely small cloud particles can dispose of excess
energy. This knowledge is necessary to understand processes in
the atmosphere that affect global climate change. The models
that have been built to describe climate change contain a major
source of uncertainty, namely the effects of clouds. The UN
Intergovernmental Panel on Climate Change points out in its
climate report for 2007 that new knowledge is needed in this
field. It is namely the case that clouds can act in two ways:
they may be a mirror that reflects radiation from the sun back
into space, and they may be a blanket that seals in the heat
emitted by the Earth. Mapping the formation and dispersion of
clouds may, therefore, be a key step in climate research. "One
important stage is understanding the fundamental properties of
the particles involved", says Erika Sundén, do