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National
Oceanic and Atmospheric Administration (NOAA)
Leeds
researchers are aiming to unlock the secrets
of the British weather, bringing forecasters
one step closer to that elusive holy grail:
the ability to predict exactly where, when
and how much rain is going to fall.
“There’s still a lot we don’t
know about exactly how rain is formed, so
it’s no surprise that the forecasting
models don’t always get it right,”
said Dr Alan Blyth from environment.
Most rain in the UK is caused by ice crystals
growing to such a size that they fall to earth,
melting as they enter warmer air. But how
and when these crystals form in cumulus clouds
still isn’t clear. Some water droplets
in clouds will freeze and begin the process
at –10C; others need temperatures closer
to –40C.
Using
the latest equipment, the research team will
measure the size and shape of ice crystals
in the clouds from a specially equipped NERC
aircraft. The plane travels faster than 100
metres a second, yet its ‘cloud particle
imager’ can capture pictures of ice
crystals just 0.001mm in size.
“The ability to take pictures of such
small ice crystals means we can see what’s
happening at a very early stage of the process,
while the crystals are just starting to form,”
said Dr Blyth. Their findings will be fed
into the forecasting models to provide more
accurate predictions.
The research is a collaboration with the Met
Office, UMIST, the University of Hertfordshire
and the national centre for atmospheric research
in the USA.
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