Thursday, October 1, 2009

No earthquakes, no tsunamis, just BIG clouds...

October 1, and China is celebrating their 60th National Day. This week there have been earthquakes in American Samoa and Sumatra, tsunamis in Samoa, and a tropical cyclone over Vietnam. But I am safe, since I am none of those places. I am in Malaysia, where we are only getting BIG clouds on these searingly-hot afternoons.

(Left: Cumulus building over South China Sea)

Walking home this afternoon, I enjoyed watching a very large cumulus cloud building up over the South China Sea. These two photos do not do the cloud justice since the photo is only a two-dimensional medium. One has to be on the street looking up into the awesome three-dimensional object to appreciate truly its scale of grandeur and beauty.

I could bore my readers with technical details about cumulus clouds, but basically the term means "heap" or "pile" in Latin, and it looks like puffs of cotton heaped up into a massive pile. Cumulus form on hot afternoons, and is a way for heat to be dissipated and moved around in the atmosphere. Much of the heat goes into evaporating water from the ocean surface, which then rises and cools, becoming visible water vapour. As it rises and cools further, droplets of ice water form on things called aerosols: tiny bits of sand, salt, dust, etc., that provide the nucleus around which the water vapor can condense. The tropics are ideal for the formation of cumulus clouds for there is ample supply of heat, water (ocean surface), and aerosols (airborne salt particles).

If a cumulus cloud picks up enough moisture, it can build up to great heights and transform into a cumulo-nimbus cloud, that brings lightning, thunder, and heavy rains.


  1. I hear KL had a shake up? My mum in Seremban says she did not feel a thing.

  2. We never seem to feel any of those earthquakes that occur in Indonesia.