Friday 2010-10-01 Dev. update and Discussion

[philip.ed]

Originally Posted by winny

Did this forum suddenly turn into the Met office or something?

Go here and look at some clouds, then stop generalising.

My question was directed to Oleg, not to you. I have no need to explain myself to you. I have supplied evidence, and posted calmly without whinging or whineing. My original post was nicely structured, and simply asked whether these clouds models were still WIP. You blew my post way out of proportion. yet why should I have to explain myself to you every week? Are you Oleg's sacred messenger? Have you spoken to him personally and do you know what kind of realism he is aiming for? No.
Not that I am doing you a discredit, but your constant belittling of simple posts is just boring, Winny. It happens most weeks and just leeds to flame wars. I know I add to it by replying to you, but it's just boring now. I am not some cloud nut. I based my observation on what I see most (summer) days in kent, and even throughout the year the type of clouds un question (cumulus off the top of my head) will form quite profoundly. The clouds in SoW currently look like cotton-balls, and have no profund shape.
Read this:

Cumulus clouds are a type of cloud with noticeable vertical development and clearly defined edges. Cumulus means "heap" or "pile" in Latin.
As air rises, warmed up by the ground, the temperature falls by adiabatic effect (fall in pressure) to an average rate of 0.65 C per 100 m of altitude.

At 15 C (the average temperature worldwide) a cubic meter of air can contain 14 grams of water. No more.

As the rising air cools down, it has less and less place for water vapour and soon the temperature reaches what is called the dew point, i.e. when the air is 100% saturated and cannot cools any further without condensing in droplets; the cloud.

The base of the cumulus is flat because it is exactly the place where the air reaches the dew point.

But once 'in the cloud' the air cools down at a lower rate because the condensation of water creates energy released as heat. Because of that, the air inside the cloud continues to rise until, eventually the temperature becomes even with the surrounding temperature and the convective rise stops.

The reason the top of the cumulus is cauliflower shaped is that, each 'bump' is in fact the top of one cell of warm air that has been rising.

Such cells, often called thermic cells are what glider pilots are looking for because they use it to circle in and climb. You will also see birds like seagulls and eagles taking those 'elevators' to gain altitude without effort.


Thankyou Winny. I researched it for you, and I think this answer answers the question


@Slipball: you may be right about seeing the bottoms of the clouds, as the view in the shots is slightly above them. Nonetheless, there is no defined shape that leads to the bottom of the clouds, as one might see when flying above clouds. It is hard to explain, but my quote (I feel) gives a good explanation of this paticular type of clouds