Uneven Heat Distribution on the Earth Surface -Why ?

So on Monday the 22nd we had our Geog class and came out of it much brighter ( literally)!
We started of the lesson with a cool experiment to understand how the 'position' of the Sun affects the amount of insolation received by the Earth.


As the image above shows, we used a flashlight as a analogy to represent the sun and how the surface area of the Earth receiving insolation increases as the sun moves away from the Earth. Figure A represents the position of the Sun overhead where the heat is focused and concentrated on a small area and is more intense, while Figure B shows the Sun's rays hitting the Earth at an angle where heat is diffused and dispersed over a larger area.

Another concept we discussed was how the spherical shape of the Earth resulted in uneven heat distribution on Earth. The angle of solar incidence differs from place to place in Earth, with the polar regions receiving the sun rays most obliquely (acute angle) and the equator receiving the Sun's rays from straight overhead (right angle). As the diagram above shows, the solar energy received at the poles is much lesser that the solar energy received at the equator. Another reason for this phenomenon is that the white ice and snow found at the poles increases the albedo at the poles, resulting in lesser energy absorption ( +ve feedback).

There were some question that were raised in class and were answered in the next lesson so you'll have to wait for the next post to satisfy your curiosity !

Krittika (07)

IS 2104 Peer Assessment Form and Score & Comments Form for Individual Essay

Dear JH403,

Here is the link for you to do a peer assessment on the work of a friend or classmate. Do note that having your work peer assessed is a pre-requisite for the submission of your Individual Essay. If your work isn't found to be peer assessed, it will be rejected immediately without notification. Do note that the teachers will use a similar template to grade your work.

For the form, please click on the link below.
Peer Assessment Form

Of course, it doesn't make much sense for someone to edit your work and yet be unable to see their comments. To see the score given by your friend as well as the comments, click on the link below.
Score and Comments

Do take note of the score, it's unlikely that the teacher would give you a higher score than what your friend has given. Thus, pay close attention to the comments given as it'll provide direction on how you can improve your script.

Finally, do take note that this Peer Assessment must be completed by 1 March, Monday, 6:00pm.

tks,

Cloud and Rain Formation

What we learn during the 2 lessons after the cloud making was mainly on the rain formation.

1. Atmospheric Moisture

- maintains life on earth

- keep our planet at habitable temperature

- balance the heat budget

2. Condensation

- radiation cooling and advection cooling (horizontal movement)

- orographic and frontal uplift and adiabatic cooling (rising movement)

3. The main point of the lesson was the study of the orographic rain

This happens when there is a mountain next to a sea or ocean. On the windward side, there is the sea/ocean. The wind brings the water up and lenticular clouds form on the leeward side of the mountain. On the leeward side, the rainshadow effect occurs due to adiabatic warming.

Rainshadow effect: where precipitation is noticeably low and the air is drier.

Adiabatic Warming: happens over a big area where the air pressure increases causing air parcels to compress and hence the area warms rapidly.

Examples: California(rains alot), Pacific Coast(alot of water) [windward] ----> Death Valley(desert) [leeward]

Jasmine :)

The ozone layer is important!

Hello, sorry for the late post. I couldn't sign it for a long time until I realised I typed the wrong username yeah ):

On the 24^th of January in IS2104, we learnt the composition of air and the structure of the atmosphere. Our air comprises of 78% nitrogen, 21% oxygen and 1% of other gasses. Carbon dioxide only comprises 0.03% of the air around us.

We also learnt how the ozone protects life from UV rays in this simple chemical equation:

UV rays + O3 --> O₂ + O
The UV provides energy to break the ozone into an oxygen molecule and an oxygen atom, thus being absorbed by the ozone layer.

We also learnt 6 simple steps on how and why CFC can destroy the ozone layer.

1. 1.UV radiation hits CFC molecules

2. 2 Chlorine atom breaks away

3. 3 Chlorine atoms hits ozone molecule

4. 4 Chlorine atom takes one oxygen atom to create chlorine monoxide and leaves one molecule of oxygen

5. 5 The oxygen atom hits the chlorine monoxide molecule

6. 6The oxygen atom will combine with the oxygen in the chlorine monoxide, leaving the chlorine free and repeating the depletion process of the ozone.

It can also be summarized in 2 simple equations.

ClO + O₃ --> ClO + O₂
ClO + O --> Cl + O₂

And I found this comic strip on the internet, maybe it might give you guys a better explanation if you all still don’t get it (:

Temperatures at the thermosphere can reach beyond 1200 degrees Celsius and yet it’s freezing up there. Why is this so? It is so near vacuum up there that the air is thin and there is low pressure. There is not enough contact with the few atoms of gas to be able to transfer heat, and thus you do not feel the heat of the thermosphere. However, you might freeze to death up there because the pressure is so low that the boiling point of blood will decrease significantly and thus will lead to death.

Yes so lesson learnt, never go up to the thermosphere.

And yeah, quite simple right today’s lesson (: Hope you have an awesome day ahead.

Erina Tan (4)
JH403

CARBON CYCLE

The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, hydrosphere, and atmosphere of the Earth. It is a very important cycle as it allows for the fourth richest element to be cycled and reused.

In the atmosphere, carbonic acid (H₂CO₃) forms by the reaction of carbon dioxide and water. This weakly acidic water reaches the earth as rain; it reacts with minerals at the earth’s surface, slowly dissolving them into their component ions through the process of chemical weathering. These component ions are carried in surface waters like streams and rivers eventually to the ocean, where they precipitate out as minerals like calcite (CaCO₃). Through continued deposition and burial, this calcite sediment forms the rock called limestone. This cycle continues as seafloor spreading pushes the seafloor under continental margins in the process of subduction. As seafloor carbon is pushed deeper into the earth by tectonic forces, it heats up, eventually melts, and can rise back up to the surface, where it is released as CO₂ and returned to the atmosphere. This return to the atmosphere can occur violently through volcanic eruptions or hotsprings.

Biology plays an important role in the movement of carbon between land, ocean, and atmosphere through the processes of photosynthesis and respiration. Plants take in carbon dioxide (CO₂) from the atmosphere during photosynthesis, and release CO₂ back into the atmosphere during respiration. Carbon is released through the decay of animal and plant matter as bacteria and fungi break down the carbon compounds in dead animals and plants and convert the carbon to carbon dioxide; or burning of biomass.

In the oceans, phytoplankton (microscopic marine plants that form the base of the marine food chain) use carbon to make shells of calcium carbonate (CaCO₃). The shells settle to the bottom of the ocean when phytoplankton die and are buried in the sediments. The shells of phytoplankton and other creatures can become compressed over time as they are buried and are often eventually transformed into limestone. Additionally, under certain geological conditions, organic matter can be buried and over time form deposits of the carbon-containing fuels coal and oil. It is the non-calcium containing organic matter that is transformed into fossil fuel. The carbon is emitted through burning fossil fuels and limestone.

BY: DOAN VIET HONG (3)

Bibliography:

John Arthur Harrison, Ph.D. "The Carbon Cycle: What Goes Around Comes Around," Visionlearning Vol. EAS-2 (3), 2003.
http://www.visionlearning.com/library/module_viewer.php?mid=95