Arctic Clouds: A missing puzzle piece

Ideas we will cover

• How thick is the atmosphere?

• The climate system is COMPLICATED

• Greenhouse gases warm the planet

• Aerosols cool the planet

• Clouds can warm or cool the planet

• (New Vocabulary: Optical Depth)

• Arctic clouds are warming the Arctic while other clouds are cooling the planet because……….

Thinking about scales

How thick would the atmosphere be on my earth ball?

Let’s do a little calculation:Radius of the earth = 6378 kmDepth of the atmosphere = 8-18 kmRadius of my beach ball earth = 300 mm (30 cm)

10 km x mm----------- = --------------6378 km 300 mm

Depth of the atmosphere on my beach ball = 0.46 mm(Find something that is about 0.46 mm thick! Look at the mm marks on

a ruler) About 2-3 sheets of regular paper? Note, at the poles, the atmosphere is the thinnest

Guesses????

It’s a very complex system!

Greenhouse Gases

Short wave(Solar Energy)

Long waveThermal Heat

Short wave(Solar Energy)

Long waveThermal HeatGreen house

gases make thereflected thermalarrow bigger andWARMS the earth

Aerosols

Short wave(Solar Energy)

Long waveThermal Heat

Short wave(Solar Energy)

Long waveThermal Heat

Aerosols (smoke and dustmake the reflected shortwave arrow bigger andCOOLS the planet

How do clouds transmit and/or reflect radiation?__________

Do clouds cool down or heat up the Earth’s climate?

Short wave(Solar Energy)

Long waveThermal Heat

Short wave(Solar Energy)

Long waveThermal Heat

It turns out that clouds can do both. Clouds can make the reflected short wave arrow bigger and COOL the planet, but they can also make the reflected long-wave arrow bigger and WARM the planet

Which cloud effect will win????

WARMER!!!!

COLDER!!!!

First question is why can clouds both cool and warm?

Why do these clouds look so different?

Fabulous book by Mark Cassino

Ice clouds pretty, but not very effective at reflecting light or heat

Water clouds are very dense and good at reflectingand absorbing light and heat energy

Question you should be asking……Hey! It’s very cold in the Arctic, why are there ever any water droplets in the cloud? Shouldn’t they be frozen?

This is one of the most surprising discoveries that we started to make only 10 yearsago. Arctic clouds are full of layer of “super-cooled” liquid water all year. This ismaking big changes on how Arctic clouds are considered in the earth’s climate Puzzle. They have a much larger effect on the surface then expected

Long waveThermal Heat

Long waveThermal Heat

Short wave(Solar Energy)

Short wave(Solar Energy)

Think about what will happen when there is nosun?

What effect will win then?

Another factor to consider

Clouds can be “umbrellas” or “blankets”

Cooler!!!! Warmer!!!!

And the winner is…..

In our arctic cloud activity we will look at how an ‘ice cloud” and a “water cloud” change heating and cooling of the

surface and speculate about the total effect of clouds is in the Arctic………..

Hint for the activity: The Arctic is very very very very very very very very very very very dark all winter long…………..

Optical Depth is a measure of transparency and is how scientists measure “how thick” a cloud is to

light and heatin general, clouds made of

snowflakes have lower optical depth then clouds made of water droplets

Thanks for listening……