WE LOVE GEOGRAPHY <333

Water Features! 5th May ’09

2009-05-10T01:14:00.000-07:00

This was Ms Tang’s second last lesson with us, and it was the one of the few times when I actually paid extra attention to the lesson, partly due to the fact that I had to do this blog post. However, I found this lesson rather interesting, when we learnt about waterfalls and rapids. This was what we learnt…

The formation of waterfalls: As water flows over the bedrock, the less resistant (‘soft’) rocks erode first. As the less resistant rocks keeps eroding, the gradient of the slope gets steeper, thus the formation of waterfalls. There is usually a plunge pool at the end of the waterfall, due to the force of the water hitting the bottom.

The retreat of waterfalls: Eventually, the more resistant (‘hard’) rocks will start to erode, thus the gradient gets less steep. However, the main cause of the retreat of waterfalls is the collapsing of the overhanging hard rock due to the erosion of the soft rock.

The formation of rapids is almost similar to that of a waterfall. The ground consists of alternate layers of ‘hard’ and ‘soft’ rocks, with the ‘soft’ rocks eroding first, thus forming a ‘step-like’ structure that resembles a mini waterfall.

Reflections:

Learning about the formation of these natural wonders is rather interesting. It seems so well planned yet it is a natural process, thus I enjoyed the lesson thoroughly (it’s my first time complimenting on Geography). Lesson was as usual, in a hot and stuffy classroom, everyone was noisy while the two groups were presenting on their respective topics. I finally realized that geography is actually a subject which ‘makes sense’. For instance, the steeper a slope of the waterfall, the faster/more the water flows, thus the formation of a waterfall…etc.

-Kevin (finally...)

2 May 2009

2009-05-02T00:33:00.001-07:00

Hi 04, let’s revise what we have learnt from the previous lessons.\

*Three types of load:

*Erosion processes:
Corrasion (abrasion): the current picks up materials and rubs them along its banks and bed  the river erodes both horizontally and vertically
Attrition: The rocks collide with each others and break into smaller pieces, and become more rounded
Solution (corrosion): The word solution is used for both transportation and erosion process, but their meanings are slightly different. Solution in transportation means that the substances are just in the water, no chemical change; whereas when we talk about solution in erosion process, they will not be the same. (e.g. in the booklet: “Water contains dissolved CO2 from the air and this may react with limestone and chalk, causing it to dissolve).
Hydraulic action: the sheer force of water pushes into cracks at the river bank and the bank will gradually collapse

* Hjulstrom curve: a graph which shows the relationship between current velocity and particle size

The first line is the critical erosion velocity line: minimum current velocity before the particles are eroded.
The second line is the critical deposition velocity: minimum current velocity before the particles are transported.
Generally, when bigger the particle, the greater velocity needed to pick it up (transport) or erode. Very small and light substances like clay are very easily carried along by the current. However, because the clay particles tend to stick together, it requires higher velocity for the particles to be eroded.

Reflection:
As we gained more knowledge about Geography, I think that we are learning more of the “what” than the “how”. The knowledge in physical Geography is not so hard to get, since we are just accepting everything as fact. I feel like we are trying to make sense of common senses, in a more logical way, and ‘simpler’ way. At the basic knowledge of physical geography, the scientists mainly worked on putting our common knowledge from nature in to a neater and more organized table, for us to see the connection between them, and then make up even more connections (which we need to do ourselves).
I think that most of us would find it kind of boring to keep learning the “what” for so long. However, if we can link the knowledge together in a big picture, it would feel like using Lego to build a model of our nature, with more and more pieces after each lesson :).
I agree with Tung that ‘how’ is more important than ‘what’ (even though he was talking about different things anyway). However, ‘what’ is fundamental. If we don’t know what the problem is, it will be very hard to figure out how to solve the problem.
So, for the time being, let's enjoy Lego! :)

By the way, as I searched the internet, I found this website which contains a lot of useful presentation slides that we can use for our references:
http://www.slideshare.net/maliadamit/river-presentation-presentation (it has a mind map at the start, linking the river processes to different landforms, and then presents the knowledge accordingly)
http://www.slideshare.net/jacksonthree/river-processes-and-landforms (very long slides and I don’t really get the flow of the presentation, but I found it interesting because it has a lot of pictures in real life)
There are also similar slides in the website, hope you find this useful.
And enjoy the rest of weekend!!!
Jenny

RIVERS!

2009-04-20T04:46:00.000-07:00

Hello guys!I am really sorry for putting up this post late-.-||. Anyway, thank God, Guzheng SYF is finished!Hooray!XD
OK,let's do some revision. Do you still remember what we learnt on 17th of April?

1. River---Man and civilisation
River is so essential for human development. And learning about the essential living conditions for humans is also important for us. We find out that great civilizations have always flourished alongside rivers. For example, the Yellow River Valley, is always thought to be the cradle of The Chinese civilization. And the Nile River valley in Egypt was the site of the world's first great civilization. Our pretty teacher Ms. Tang also showed us a picture of Nile Delta (which is screenshoted from her favourate Google Earth), and we saw that there is a very high population density along the river but few people live elsewhere in that region.

The explanation is as simple as this:
River-->water necessary for farming & drinking--> better living conditions--> more people live and multiply along rivers.

2. Model-making Time
The second half of the lesson was used for model making activities. We were supposed to make models of deltas, waterfalls, floodplain and levees, meanders,rapids and ox-box lake with plasticine and put them in order according to how a river flows. I feel that this kind of hands on acitivities really helps in understanding. I can have a clear picture of how different parts of a river look like and why they are located at where they are.
Yeah this is the whole model done by Loulou,Jenny,Binghui and YIXUAN!

Before making a model like ours, you must understands what the different parts of the river are.:)By the way, Ms Tang showed us the photos of the waterfalls she took in U.S.,and those photos are cool!:)

OK, lastly, let me ask you a question that we have already discussed in class:
Is the speed of the water in the upper cause always the fastest?Why?

Done by:

GEO-PRESENTATION by YINGZHENG.-

2009-04-07T09:02:00.000-07:00

Today’s lesson was a short lesson, but we did learn many important things. Firstly, we learnt in previous lessons about the equation regarding the hydrological cycle. The individual factors that can change are precipitation, evapotranspiration, total streamflow, and also change in soil water storage. These things alone, when changed, will affect our water cycle. We also looked into things like storm hydrographs and rainfall. Different groups took turns to present on the different factors which affected rainfall and such. This was different from an ordinary lesson as it was actually our classmates teaching us. It was very interactive as we asked many questions and clarified many doubts. We were also able to visualize better as there were drawings to aid us.
What we learnt today was mainly about the various factors that affect the hydrological cycle, and why they do. This was then referenced to the smaller factors that defined the water cycle. One factor that affected the activity of the hydrological cycle was afforestation and deforestation. Using the equation we learnt previously, during afforestation, runoff decreases, evapotranspiration increases, and soil water storage decreases. This is because there are more trees, there is an increase in interception, thus there will be less runoff. More tress would then also lead to higher evapotranspiration rates, and their roots, taking up space in the soil, will decrease the soils water storage capacity.
Another change in surrounding was deforestation. Deforestation is actually the exact opposite of afforestation. During deforestation, the number of trees decreases thus resulting in less interception, and more runoff. Similarly, less trees would result in less evapotranspiration, and the lower amount of roots in the soil would then increase its water storage capacity.
Next, there’s agriculture. Agriculture is the growth of vegetation. And as such, infiltration decreases, stemflow and root absorption increases and blocked surface area also increases, thus, throughflow and baseflow would decrease.
The last point presented was grazing. Grazing reduces the amount of vegetation, thus increasing infiltration. This would then result in an exact opposite of agriculture, therefore increasing total throughflow and baseflow.

---YINGZHENG

2009-04-03T18:44:00.000-07:00

As we advance in our learning, I realized that we go more and more indebt into things. For Geography, I always thought that the water cycle was simply just the evaporation of water, formation of clouds, then rain. Although this still holds true, there are now many factors that we know that have to be taken into consideration before this “simple” process can take place. I also did not know that equations and graphs are actually constructed just to study the rain and its effects. Also, it did not occur to me that so many factors could cause a change in the storm hydrograph. Factors including: drainage density, shape of basin, steepness of slope, amount of rain, presence of vegetation and rock permeability. The range of these factors is so great that it is hard to imagine that the difference of something as minute as rock permeability as compared to something as large as drainage density can both have an effect on the hydrograph. Moreover, a simple tweak in only one factor such as the presence of vegetation can actually change the hydrograph by quite a lot. I cannot imagine how much thought has to be put in just to construct a graph that has majority of its factors different from the original graph. Through the learning of these factors, I found out that some things could be inferred from as long as you knew the definition of the term and some background knowledge. For example, the steepness of a slope. From basic knowledge we know that the steeper a slope is, the faster things can roll down. Thus, we then infer that the faster the rain droplets flow down the hill, the shorter is the basin lag time as the river would peak faster. There are some things that we can easily infer when we are studying, we just need to dig out the necessary background information and would be able to arrive at the conclusion.

Janell

The water balance~! by zhang binghui

2009-03-31T06:19:00.000-07:00

Hi, everyone! This is Binghui. Today it's my turn to write the blog.

Basically, what we learned today is The Water Balance.

Here is a picture of hydrologic cycle for your better understanding:

The water balance is a simple equation which describes how precipitation may be accounted for within a drainage basin.

A general water balance equation is:
P = Q + E + ΔSwhere
P is total precipitation
Q is total streamflow (runoff)
E is evapotranspiration
ΔS is the change in storage (in soil or the bedrock)

Some examples of the factors:
Q can be affected by dams, but the teacher said not very sure about it.
E can be affected by vegetation
ΔS can be affected by amount of soil and also type of soil.
The water balance is used by hydrologists to plan and manage water supply within a drainage basin. It can be used to suggest possible water shortages for which special measures like hosepipe bans can be implemented to preserve stocks. It has implications too for irrigation, pollution control and flooding. The water balance can be illustrated using a water balance graph which plots levels of precipitation and evapotranspiration often on a monthly scale.
There are some additional points:

1. Precipitation in the form of rain, snow, sleet, hail, etc. makes up the primarily supply of water to the surface. In some very dry locations, water can be supplied by dew and fog.

2. Evaporation is the phase change from a liquid to a gas releasing water from a wet surface into the air above. Similarly, transpiration is represents a phase change when water is released into the air by plants. Evapotranspiration is the combined transfer of water into the air by evaporation and transpiration.

3. Soil moisture storage refers to the amount of water held in the soil at any particular time. The amount of water in the soil depend soil properties like soil texture and organic matter content. The maximum amount of water the soil can hold is called the field capacity. Fine grain soils have larger field capacities than coarse grain (sandy) soils. Thus, more water is available for actual evapotranspiration from fine soils than coarse soils. The upper limit of soil moisture storage is the field capacity; the lower limit is 0 when the soil has dried out.

4. The change in soil moisture storage is the amount of water that is being added to or removed from what is stored. The change in soil moisture storage falls between 0 and the field capacity.

Take note of this, ΔS can be zero. There are some reasons we discussed in class:
1. It can be raining all the time caused the soil saturated, thus ΔS become zero.
2. It can also be no rain at all caused ΔS to be zero.

Lastly, I am not very sure about the question the teacher asked us in class:
Can S be reduced? The answer is yes.
But what is the reason? Can someone who understood this tell me the answer?

I think the lesson is too short, only half an hour.
These are all what we learned.
Thank you!

Binghui
31, 01, 2009

geogpost-o-matic by Matthewlimtianwang

2009-03-30T07:11:00.000-07:00

Hey All! This is Matthew And I'll be blogging what we learnt last lesson.
First off, we started talking about water from the hand out that we received.
We deduced that water.
-Has a high specific heat capacity.
>Its able to absorb more heat without turning into gas.
>Very big range in between states, solid, and gas.
-Many many things have water in it.
>Us!
>Plants
>Many things need water to manufacture.
-Drinkable
-Hydrogen bonds
>DNA
>Ice floats
-Ice
>Insulator, it protects the water that is not exposed to the air.
-Universal solvent
-The Earth is mostly water, but we cannot use ocean water as.
ITS TOO SALTY BABY!

okay, time to go on to the next part of the lesson.
the...
HYDROLOGICAL CYCLE
and unusually the caption is,
"what goes around comes around"

Made up of many parts,
Infiltration
Overland flows
etc..

I will scan in the entire picture next week when i get my scanner fixed.
Some terms that we've learnt that day was:
Infiltration Capacity - Rate at which water soaks into the soil.
>affected by:
->Saturation of water.
->Compaction, type of soil.
->Surface area exposed to the water.
->Porous, permeability of the soil.
->If the soil is frozen or not
->Vegetation

Water table - Demarcates the saturated and unsaturated zone, its not the same throughout the year.

Methods of input: Precipitation
Methods of output: Evotranspiration, which is a combination of transpiration and evaporation.

Storages - Groundwater, soil moisture.

Flows - Infiltration, overland flow.

Flows can also be in different categorieroots take in water
Inbetween surface and groundwater - Through flows.
Groundwater - Base flow
Vertically in the soil - Percolation

Interception - Anything that hinders movement of water from precipitation
> Vegetation - reduces impact of rain drops, reduces rain splash erosion.
->stuck in leaves
->roots take in water
->stemflow
->Throughfall

THATS ALL FOLKS!
bwahha.
Matt!

2009-03-14T03:03:00.000-07:00

My apologies everyone, I saved it in my comp and forgot to post. So it’s a little back-dated somewhat. I’ve made changes and the last part of reflection was something I added in recently. Yup, so here goes.

Hello.

I’m going to briefly run through today’s lesson and then do some reflecting.

Goodbye Peixin, Hello Ms Tang.

It was Ms Tang’s first lesson with us.
Some interesting notes:
1.

Good attitude
Engagement
Ownership
Grow!!

2.

Desert is spelt as desert, if you forget and spell it like dessert, do look at the picture below.

3.

Some people have funky-looking camels

Point 1
Wind moves from HIGH pressure to LOW pressure

Point 2
Cold air --> high pressure
Hot air --> low pressure

Point 3
Air rises --> rain

RECAP
The Hadley and the Polar cell are driven by the SUN.
The Ferrel cell is induced by the Polar and the Hadley cells.

The desert belt occurs where the air subsides.
Air subsides (where the arrows go down)
--> no uplift of air (i.e. air does not rise)
--> no rain
--> deserts

REFLECTION
I was whacked during lesson and it was hot and noisy.
I learnt that concept maps are useful for firstly identifying key concepts and secondly it helps us see the links between ideas and concepts.
Eh, I haven’t got much to reflect on the one and a half hours.
We kind of just revised some concepts, got to know ourselves better, and did a concept map on what we have learnt thus far in this module.

---

As I sit through, not just this lesson but all our lessons, I just kind of keep thinking that the world we live in is so huge, so awesome, so wild.
Yet here we are, tiny and insignificant yet trying to contain this gloriousness into words and diagrams.
Trying to manipulate, predict, exploit great things we can neither understand nor control.
We see a little and we make much of it.
We feel a little and we assume much from it.
We think a little and we decide we can re-create it.
Who are we?

Makes one think huh. Exams almost seem frivolous compared to this.
Ever sat back, looked at those hand-drawn air-cell diagrams and think, and silently ask in the general direction of the teacher, have you seen the earth as a ball? Have you experienced the force of tornado? Have you even tasted the brutality of the desert? Have you seen wind move in ways beyond all humans can imagine?
Sometimes I look at geography, and augh, how shall I say this.
Like,
WAKE UP, HELLO, YOU’RE TALKING ABOUT THE EARTH LIKE IT’S A BALL,
OF THE GALAXIES LIKE IT’S YOUR BACKYARD.
Wake up, ever thought of how small and puny our efforts are to record all these?
Yet we do it, why? I honestly don’t know.

Hahahahah, I sound like I’m ranting but I’m quite serious.
We, as students, sit in class, learning about things of such complexity and beauty, yet all we care about is, oh crap this module is gonna kill my GPA, or aiya only 3 credits.

I’m just suddenly appalled that we are trying to squeeze something great and make it small, boring and “muggerable” (which means able to mug for).
Sigh.

I think as we drill down deep, we find that there are things we just do not have answers for.
Yet we keep asking. :D
Humans ARE complex huh but also beautiful, like the rest of the earth.
So in conclusion,
As we learn all this, doesn’t even need to be geography, can be science or even LA,
I guess it’s important that we take a step back, and look at things from a different perspective eh?
One where grades are not everything, one where the classroom is not the ends of the world, and one where you know, we can really just stare in awe of the glorious wonder of all creation.

The end.

Esther.
PS: and I thought I had nothing to say.

IS 2104 lesson on 5th march 2009

2009-03-07T05:39:00.000-08:00

It was our last IS2104 lesson for the term. Naturally, everyone was sad about it. Worst still, it was only our new physical geog teacher second lesson with us, which is such a pity since she's so nice.

This is her!

That day was hot and humid, but because of that wonderful lesson that we had, the day seemed less painful to get through. Our new geog teacher, (who's name i forgot, sorry), was charming and nice.

Anyway, back to the lesson. That final lesson for the term was spent on going through wind patterns. We talked about how winds are formulated on earth. The following picture simply put together what i want to tell you all.

yup, so basically that sums up everything about wind patterns. Remember the directions the wind in each section blows in. They are really important. Also, you must remember the all the names given the each wind pattern in each section of the Earth. I must admit, the names are really weird. And cute, but this makes it easier to remember. :)

After that, our new geog teacher evaluated the mind map that everyone did last week. There were some that were great, but there were some that were not that good. I'll state down which is the best, and you can use that for revision.

This part is great. Because the hardley cell and polar cell had a connection with the ferrel cell. Yes people, there is indeed such a connection, so remember.

Ok, this is quite a bad mind map. The basic ideas are there, but details aren't being made. If it was elaborated on much more, it would have been better.

This one is the best based on our new geography teacher. This is because the carbon cycle is shown without really stating it. ( notice the crooked lines there if you don't know where to find it). But of cause its not totally perfect. There are details missing here and there, but its alright.

For the best result, it is suggested that you make your own mind map, while using the good points from each of the three mind maps ive shown you.

This is as everyone knows, the weekend before ass week. When you do not feel like studying, like how i'm feeling right now, but go and sleep. It works. And don't feel all guilty about slacking a while from time to time. Because all work and no play makes jack a dull boy. :)

Alright ending off here. Jia you everybody! jeremy

smile and don't strees :)

Tilt and Shape: Season 2 (27th Feb)

2009-03-02T08:50:00.000-08:00

Hello.
Sorry for the delay in posting. It's basically the same as mak's, but probably not so defined and content-based. Because i wasn't in school for that lesson, and the rest of the class wasn't sure about it anyway. Hence, we revised everything again for this lesson. By the way, could someone help me explain how autumn and spring come about and how are they different? Sorry, I didn't get it and it wasn't really explained in class that day. Thanks!

Why are there seasons?

Seasons occur due to the Earth’s tilt.
Note: Radiation from the sun does not weaken with distance. It only gets cooler when the distance between you and the sun is larger as the radiation is spread over a bigger area and is thus less intense. So, when explaining about the sun’s rays, cannot write hotter/colder.

1. As the Earth is so huge, a small tilt in the Earth’s axis will result in a change of distance between the Sun and each hemisphere. Hence, when the northern hemisphere is inclined towards the sun, meaning it is nearer the sun, the Sun’s rays are/solar radiation is more intense on the northern hemisphere, hence it experiences summer. They/it are/is less intense on the southern hemisphere, as it is further away from the sun, thus it undergoes winter.

3. The southern hemisphere is inclined towards the sun, meaning it is nearer the sun, so the Sun’s rays are/solar radiation is more intense on the southern hemisphere, hence it experiences summer. They/it are/is less intense on the northern hemisphere as it is further away from the sun, thus it undergoes winter.

Explain the distribution of Earth’s Climate.

Basically everything is explained in the diagram. Hence, the content seems very little, haha. Anyway, pardon my messy handwriting(:

I feel that this lesson was quite informative, as I've never known that the world's climate was brought about by the movement of air within the atmosphere. I've not looked at it as a whole system before, only from certain segments, like the water cycle. Therefore, this lesson enabled me to appreciate the big picture and how it all works out. Also, it's interesting to know that deserts are not found at the hottest area on Earth,the equator, where one would naturally expect deserts to be at. That's one point to note. Another thing, I knew that seasons were caused by the tilt of the Earth, however I did not really know how they were actually brought about. Hence, this lesson provided alot of details and explanations that added to my existing knowledge and allowed me to understand the topic more thoroughly.
The End.

- Jia Yi

Tilt and Shape (23 Feb)

2009-02-23T06:51:00.001-08:00

MAK (IE TING AMANDA) SAYS HELLO. :D

So I’m here to post on today’s lesson. Basically, the lesson was spent answering, or trying to figure out the answers for two questions.

1. Explain the distribution of Earth’s climate.

2. Why are there seasons?

Miss Lin split us into groups of threes and fours to discuss. Like, some of us were supposed to work on the first question while the rest had to do the second. Some of us were told to present our answers on the board but we weren’t that clear, so Miss Lin ended up explaining instead.

We referred to the colourful world map given to us a few lessons ago to answer the first question. It can be seen from the map that at the Polar Regions, the climate is much colder than at the Equator. Reason being, the radiation from the Sun is being spread over a larger area when shone at the Earth’s surface at the poles than at the equator. The diagram below should give you a better picture.

So, as you can see, supposedly six rays hit upon Earth - three at the North pole and three at the equator. The intensity of sunlight does not decrease due to the distance but the rays are like, spread out at the pole. So the concentration there is lesser as compared to the equator. Therefore, it is hotter at the equator! Yeah, it's something along these lines.

We learnt that this uneven heating is known as differential insolation. Insolation refers to the amount of solar radiation energy received on an area in a given time.

Okay, then Miss Lin drew another diagram to aid our understanding on the distribution of the Earth’s climate.

I only drew the Northern Hemisphere because it looks neater. :D
(I hope the diagram's correct..)

Okay fine, I'm a little lazy too but yeah. As long as you understand how the convection currents at the Northern Hemisphere work, you will understand how the Southern works too. The principle is the same, just flip the Northern Hemisphere over, using the equator (where the words "Low Pressure" are at) as the line of symmetry, and you will get your Southern Hemisphere.

I think it's damn cool to have different names to the convection currents at different parts. Besides that, I made a brief explanation on what happens at the Polar Cell. If it's too small, maybe you can look at it here.

High Pressure --> Air cannot rise --> No clouds formed --> No precipitate --> No water --> Desert --> At the High Pressure Belt.

As the air at the North pole is cold, its density is really high and therefore the air has high pressure. So, the air can't possibly rise and form clouds. Without clouds, you can't get rain yeah? And no rain means no water. If there is no water over a long period of time, the land will be dry and tata, you get your desert at the High Pressure Belt!

I guess this answers today's commonly asked question: How come there are deserts at the Tropic of Cancer/Capricorn and not at the equator?!

Also, we learnt that there are seasons because the Earth receives different amounts of sunlight at different times. Thus, during the first half of the year, the Northern Hemisphere which is tilted towards the Sun will be warmer as it receives a greater amount of insolation, while the Southern Hemisphere receives lesser insolation. The Northern Hemisphere will experience summer while the Southern Hemisphere experiences winter. Basically, during the later half of the year, the Northern Hemisphere experiences winter and the Southern Hemisphere, summer. This cycle goes on and on. And so, we have the four seasons. The equatorial countries do not experience the four seasons as the equator is where the subsolar point is. The subsolar point is the point on Earth where the Sun’s rays meet the surface at a right angle, with no change in the amount of solar radiation received throughout the year.

I’d say this lesson is pretty interesting. I mean, we get to understand how deserts become deserts. So if you actually have those fantasies of a giant blowing away all the water and drying up a piece of land to make it a desert, you should now realise that the giant does not exist. So the reason why the Earth’s climate is like this is all due to the convection currents in our atmosphere. The rising of hot air and the sinking of cold air cause the difference in air pressure which in turn causes the convection currents.

It is also amazing to find out how much a degree change in latitude or longitude can affect the amount of sunlight received. In our daily lives, I doubt a degree change actually means anything to anyone; it seems so insignificant. But wow, things are indeed different out in space.

So yeah, that’s about all for today! I hope this isn’t too screwed. :D

Rain Formation

2009-02-16T05:17:00.000-08:00

BASIS OF RAIN

So, rain formation. It's the formation of rain! How? The basis of it is that when hot air rises, the pressure would decrease resulting in expansion and then the cooling of water molecules. ---> RAIN This is done by the gases in the atmosphere which causes each molecule to lose energy.
There are three different types of rain. Convection rain, orographic (yes its the correct spelling) rain and frontal rain.

1) Convection Rain - Rain caused by the cycle of evaporation and condensation on the clouds (nothing special)

2) Orographic Rain - Rain caused by natural forces of its surroundings. (usually appears at hilly regions and mountains)

3) Frontal Rain - Rain which is created by the collision of two fronts made of different air masses, the warm front (warm air) and the cold front (cold air). The cold front would "subduct" under the warm front just like how plates subduct under each other.

Reflection
I found the lesson on the formation rather dull as it was rather common sense that how rain basically forms. The only problem is that we do not know what the names of the rain are called. For example, convection rain is basically what we learnt in like primary school. However, the other two types of rains were pretty new and interesting to learn about. Also, there was also a part which mentioned something about the physics of the system of geography which we are all learning about. Didn't find it very important though and I don't think it would be tested until a very very long time so I ignored it and slept through that part :D. (woke up 5 mins later and found out lesson ended anyway)

Nigel Tan JH404

2009-02-09T04:13:00.000-08:00

REFLECTION FOR 9th FEBRUARY GEOGRAPHY LESSON
by Ng Shou Jin.

So today we just got a new 8 mark assignment with the question as: To what extent should we be concerned about carbon dioxide emissions? After which, we watched a DVD on Al Gore and his dedication to climate changes and due to that, he won a nobel prize due to his works.

Now, who is Al Gore? He is an American environmental activist who served as the 45th Vice President of the United States, and has been in the political line for quite a long time. He presented a documentary on global warming and climate change called An Inconvenient Truth; one that was inevitable yet is the cold, hard reality of the state of the world which is falling. He was working to try to get the message across to as many people as possible about the falling state of the world, and that we humans are the major factor of its impending downfall.

Atmosphere
The atmosphere that protects the Earth is actually vulnerable as it is a thin film over the Earth, and the major disadvantage of ts thin-ness is that it is actually thin enough for human beings to change its air composition. Up above is a picture I have amateurly drawn on paint to illustrate how the atmosphere traps heat as well as reflect heat to keep the Earth's temperature just right for us to live in. Ive added in the text in the picture as well to explain how the atmosphere ensures a desirable environment for us to live in as well, as explained by Al Gore.

What air pollution is doing to the atmosphere is actually to THICKEN the atmosphere, and thus the infrared radiation trapped in the Earth does not easily escape to space, and this would then cause our problem of global warming. He also gave an analogy where the leaves also contribute to the carbon dioxide cycle which maintains the carbon dioxide cycle. During Spring and Summer, when the sun is at it brightest, the leaves of trees would 'inhale' carbon dioxide for photosynthesis; but they would 'exhale' carbon dioxide as well in Autumn and Winter where light is scarce, and the leaves would be decomposing to form carbon dioxide. Through this, carbon dioxide is repeatedly maintained at around the same levels.

However, now that the carbon dioxide level is much higher than those expected of from the last few centuries [where 300 parts per million is way too high already]. Al Gore also provided us with one of the most important concept, where

More CO2 = higher temperature,

because CO2 traps heat in Earth

That's about it for today's lesson! My conclusion for this is that we have to be concerned about carbon dioxide emissions to a high extent.

REFLECTION:

If I hadn't attend this lesson, I would not be aware that such a dedicated and passionate environmental activist called Al Gore existed. In addition, I had not really been clear of what negative things greenhouse gases like carbon dioxide do to the atmosphere as well as how it contributes to global warming. It makes me more aware for what we humans are constantly doing to promote further global warming in the Earth, like the careless burning and usage of fossil fuels or the neglection of the negative impacts of deforestation for cultivation in Indonesia etc. Greenhouse gases, in fact, are the ones responsible for trapping heat in the Earth and if it thickens the atmosphere, our Earth would get heated up.

-End.

Planetary Heat Balance

2009-02-06T05:39:00.000-08:00

Planetary Heat Balance

So what is the planetary heat balance???

Basically it is a system that needs to be in balance otherwise the Earth would either freeze or burn.

(If one day the system is not in balance, I prefer being freezed to being burned, I hate hot weather ^^)

The note is very long and complicated to read every single point in it so that I will summarize the most important points :

Shortwave radiation from the Sun enters the surface-atmosphere system and is ultimately returned to space as longwave radiation.

There are 3 main losses of solar radiation back to space .The sunlight is returned back because of

1. Surface reflection

2. Cloud reflection

3. Back scattering

There are also 3 main processes through which the energy leaves the Earth’s surface

1. The heat may leaves as sensible heat ( sensible heat is just a kind of heat that can be felt) => atmosphere by convection and conduction

2 & 3.The melting and evaporation of water transfer energy into atmosphere as latent heat

Personal comments on the lessons and the note :

I’m sure that we will find all the data provided in the note very hard to memorize and you will wonder why we have to learn all those data.

Oh, the reason is simply for you to understand roughly how much energy is transferred in and out of the Earth.

However, I personally think that all those numbers are just making just more and more confused. Those values of energy cannot be constant because if they were constant then there would be no climate change today (so good right ?!). Those values depend on a lot of other factors such as CO₂concentration, the thickness of the Ozone layer…etc… Therefore, I think you don’t need to remember all those value, you just learn the processes and understand them as a system. Forget all the Values.

One last comment about the method of the teaching is that drawing the whole system on your own is a really useful technique to study since you can explore your ability to really learn by yourself. At the same time you also learn how to analyze the information in the passage and how to synthesize them into a diagram.

Yeah, that's all for today lessons. One more time, LEARN IT AS A SYSTEM!!!!!!!!

2009-02-04T04:43:00.000-08:00

We were told (more than ten times) NOT to memorise any knowledge, but to understand everything in systems.
A system has regulatory forces, and these forces are known as positive or negative feedback.
A negative feedback is something that discourages the change. For example, when you exercise, your body heats up (the change), but you sweat, which cools your body down (the negative feedback). And negative feedback can be good, even if it's negative.
A positive feedback is a reaction that encourages the change. For example, water vapour is a greenhouse gas, so it will trap heat from the sun and cause the Earth to heat up. Because of this, more water will evaporate, and then more water vapour will built up in the atmosphere, causing the Earth to heat up further, which causes more water to evaporate and so on and so on and so on.
Then, we talked about the Carbon Cycle. This is a drawing of it. (The words are microscopic, so you may have to squint and guess.)

The black arrow labelled burning (if you really can't ready microscopic print), was caused by (guess who?) us human beings. That is why there is an increase in the amount of carbon dioxide in the air, which has led to the enhanced greenhouse effect. (This is a hint for our Climate Change essay, if you are talking about reducing carbon emissions)

The real reflection:
I thought the Carbon cycle was really interesting, because it was an example of how Mother Earth is completely made up of systems. Besides the Carbon Cycle, there is the Nitrogen Cycle, and the Water cycle, etc. Everything is somehow positioned perfectly so complement each other. For example, we do not need to worry about a shortage of water when we see the sea water evaporating, because it falls back down as rain again, and no water is actually lost. How the Earth is so flawlessly programmed amazes me.
(During this lesson, we also learned about how we needed to do an essay on Climate change.)

Goh Yi Sin JH404

Lesson 1

2009-01-19T04:46:00.000-08:00

Finally managed to sign in after ten million tries because that bimbo gave me the wrong login id. -.-

Composition and Structure of the Air

We need to know this because it is essential for our living.

Composition of Air
Nitrogen 78%
Oxygen 21%
Carbon Dioxide 0.036%
Hydrogen
Methane
Sulphur Dioxide
Noble Gases
Trace Gases
Water Vapour

Carbon Dioxide, water vapour, Sulphur Dioxide and Methane are all variable gases, because their compositions in the air are not fixed. For example, methane is apparently cow fart, so on a farmland -> more cows -> more farts -> more methane.

Nitrogen
Most prominent gas in the air.
Main source of nitrogen is from volcanic eruptions.
Nitrogen is important because it provides us with energy as can be illustrated from the nitrogen cycle which goes as follows:
Atmosphere -> Soil -> Plants -> Us/Animals (and when we die we decompose and the nitrogen goes back to the atmosphere and the soil)

Oxygen
Used in repiration
Given out during photosynthesis

Carbon Dioxide
Regulated by the Carbon cycle.
Traps heat (Greenhouse effect, which is good unless it is an advanced greenhouse effect. That is bad.)

Methane
Traps heat (Greenhouse effect)

Structure of the air

Troposphere
Tropo in Greek means to mix or to blend
Sort of represents the weather. The composition of air above is found in the troposphere. (Note that different layers have different compositions of air.)

Stratosphere
Ozone layer
Protects us from UV rays

Mesosphere
Meso - middle

Thermosphere
It is the hottest layer. Hottest molecules can go up to 2000 degrees Celsius.

The mesosphere and thermosphere protects us from meteorites.
Meteorites burn up in the meso and thermosphere before it hits earth. That is why the Earth has no craters unlike the moon, because the moon has no atmosphere.

The atmosphere also ensures stable temperatures. On the moon, temperatures in the day can go up to 200 degrees Celsius and on the night it can go to as low as -200 degrees Celsius.

The atmosphere traps heat and blocks heat. It also absorbs and reflects radiation. Half of the rays are reflected.
The heat we have at night is trapped heat. Without the atmosphere, a blanket will surely not be enough to keep us warm.

Moving air - wind. The wind transfers heat to the colder parts of the earth like the poles. That is why extreme temperatures will not affect us too much.

In conclusion, the atmosphere
1. Protects (meteors, UV, too much solar radiation)
2. Acts as in insulator (thus ensuring stable temperatures)
3. Provides us with wind (transfers heat)

Misc:
Smell of burnt wire - smell of ozone layer
Smelling too much of it is poisonous and can cause respiratory problems (MATTHEW AND NIGEL TAKE NOTE)

Reflections (because Miss Lin said to add it)
The atmosphere is very interesting. Because uhm it rocks.
Okay but seriously, I never knew how important the atmosphere was until today. So I feel that the world should make a greater effort to slow down the speed of global warming! Also use more CFC-free products so as not to destroy our precious ozone layer. You don't want some meteorite to come crashing down in our classroom during a VERY INTERESTING geography lesson huh? (;

And the world will be no fun if everybody had skin cancer.

(Oh no, I think I'm gonna fail this reflections thing. /:)

-Nadine (:

2009-01-15T05:32:00.001-08:00

Hello people this is Yvett, the blogmaster. How cool is that? WOOOO :O Anyway this post is just so that the blog is view-able. Yeah bye muggers ;D

-the current skin is temporary until further instructed by Mr Heah. Since this's about geog, we should go green..... for now