Satellites are one of a meteorologist’s best tools. Satellite images can tell us where weather systems are and how fast they are moving. They can also often help us distinguish between many things such as thick and thin clouds and high and low clouds, as well as detecting snow, fog, volcanic ash, smoke, thunderstorms, and much more.

Main types of satellite images

Up, up and away in my beautiful, my beautiful balloon… So the song goes, but what’s it actually like way up high in the atmosphere? Could we humans live up there if we wanted to, or had to? I recall David Attenborough doing a great documentary in the series “The Living Planet” (“The Sky Above” episode, BBC) where he ascended beneath a very large hot-air balloon, complete with oxygen mask and equipment for sampling for life specimens. It was surprising to discover that small insects could be whisked up there and freeze, before descending again and reviving.

As I indicated at the end of the recent post about surface tension, I've started a new thread about the amazing properties of water. This time I'll write about saturation, what it is and what it isn't. The reason I included the bit about "what it isn't" is that a close friend once asked what saturation actually was - they thought that if the air were "saturated" it was like walking through a swimming pool. Not an unreasonable deduction based on our everyday meaning of "saturation".

Earlier in the September 2009 many parts of New Zealand had frosts. This is the beginning of spring so it got me thinking about the impact that late season frosts can have on the delicate buds sprouting on trees and vines around the country.