Climbing into the alpine, the landscape takes
on an appearance similar to the arctic tundra. Growing seasons are incredibly
short with a sudden explosion of wildflowers appearing in early July and
disappearing almost as suddenly. Some of the many atmospheric changes that occur
as you head into the high country are brought on as a result of a reduction in
the density of the air.. In fact, barometric pressure decreases about 1/30th for
every 291 metres climbed. This lower density allows greater amounts of incoming
solar radiation to reach the surface. In fact, at around 12,000 feet (i.e. the
summit of Mount Temple), the radiation can be as much as 280% higher than sea
level. This increase in solar radiation is accompanied with an matching increase
in the intensity of violet and ultraviolet radiation. I don't need to mention
the higher potential for sunburns and other maladies caused by too much sun.
Don't forget your sunscreen.
For man, one of the greatest dangers of high
altitude travel is mountain sickness. The symptoms include nausea and headaches
accompanied by weakness. At high
altitude, with the corresponding drops in air pressure, our bodies have a more
difficult time extracting the oxygen we need to survive. On average, people
begin showing symptoms as they head above 2500-3000 metres. The effect of
individuals varies greatly and some people may not feel the effects at all.
Others rapidly suffer as they ascend. The secret is to acclimatize to altitude
and to listen to your body. If it says head down, listen to it.
All Material © Ward Cameron 2005