Today, for the being of the lesson, we revise on the PLANETARY HEAT BALANCE for a period of time.
& here’s the summary for the whole idea of the heat balance:
we proceed on with the CLOUD-MAKING experiment.
We gathered around Ms Lin outside class in groups and she started the demonstration on how to make clouds appear in a 1.5 litre bottle.
For the experiment, a 1.5 litre bottle with some water in it and a matchstick is needed. Before starting, Ms lin squeeze the capped bottle and asked us "What is happening in the bottle?" Yes, air was being compressed and uncompressed inside the bottle before and after squeezing. (that's our answer)
Next, the matchstick was lit and entingushed inside the bottle. The smoke from the matchstick was then trapped in the capped bottle. The inside of the bottle looks misty at first but soon cleared away later.
After that,
Ms Lin squeezed and released the bottle &POOF! "clouds" appeared above the water surface. We were then give the chance to play around, squeezing and un-squeezing the bottle, watching the "clouds" form.
ANDthats CLOUD-MAKING
& SO
Why do we need to squeeze and release the bottle? for change in pressure
Why is smoke needed? condensation nuclei
How did the "clouds" form?.
In short, what was the experiment trying to show?
The ability of air to hold water depends on the temperature of the surroundings: the cooler the air the less water vapour is retained.
If warm air is cooled, it will become saturated with water vapour which will later condense in to liquid or ice water (e.g. water &ice-droplets).
HOWEVER water will NOT be able to condense spontaneuosly by itself. Minute particles in the atmosphere is needed which brings me to CONDENSATION NUCLEI. Water requires a surface to transit from a vapour to a liquid.
PICTURE THIS
Water vapor molecules is moving around at a FAST speed in air. For you to see "cloud" formation, the water vapour molecules have to collide &BIND together.
BUT now, at the speed that water vapour molecules are traveling, they tend to bounce off one another instead of bonding together.
condensation nuclei will then act as a platform for condensation to take place.
We also learnt about the forced uplit &free uplit.
FORCED UPLIFT
stable air forced to rise aboce relief barrier and ten to fall back toward lower level asap.
NO strong updraughts, collision process INEFFECTIVE
produces slight drizzle, hill fogs
FREE UPLIFT
unstable conditions
rising air continues to rise once triggered.
clouds may reach high in the atmosphere (temperature far below freezing)
both collision and icing takes place
HEAVY rainfall of high intensity
SEEDER clouds - high lvl clouds
High clouds are cirro-form clouds being composed mostly of ice. Generally found above 7000 meters, these clouds include: cirrus, cirrostratus and cirrocumulus.
GREAT rainfall intensity
FEEDER clouds - low lvl clouds
Low clouds are those that form from the surface up to 2,000 meters. Low clouds include: stratus, stratocumulus, and nimbostratus.
SIMIN(:
And again Geography has been learnt and taught in an awesome way. Cloud making experiments! I think it was a very interesting experential way to understand cloud formations. I think we all felt like God that reigns The Waber Tottle Planet during that 10 seconds when our bottle squeeze created misty clouds. I think Geography is really fun, I love to feel smart, and now with all this knowledge on Rainfall and Cloud Formation, I'm totally going to impress my non-njcip friends by sounding so knowledgeable. If I just mentioned the "Picture This" paragraph posted by Si Min, they are so not going to talk about Water Vapour to me anymore. I can totally picture that.
ReplyDeleteThat was a very concise and effective summary of our lesson indeed! I think I now better understand what the "cloud" experiment intended for us to learn! The picture on the Planetary Heat Balance also shows the great effort you have put in for the better learning of the rest of us! Thanks SiMin! (:
ReplyDeleteThat was a really detailed entry about our lesson last week :)
ReplyDeleteRain is so interesting, and it's even more interesting looking at molecular level.
By the way, the last part, feeder clouds and seeder clouds are part of feeder-seeder mechanism :) And the info about the 2 types of clouds are very precised :)
Thanks Simin!
I love the cloud-making experiment, and it also helps me to really understand what's happening up in the sky, and why we have those fab-looking clouds. Simin's post is very concise and effective for learning! thankssss
ReplyDeletechailin
I think the experiment on making clouds was very interesting and enriching. It really made me think about the formation of clouds and rainfall. Also, i the planetary heat balance diagram helped to summarise the main points of the lesson. thanks simin!
ReplyDelete