Jingyi

Hello!

Friday’s geog lesson was basically just a continuation of the previous lesson. In the groups that we were split into, we had to attempt to answer either the question of why are there seasons or explain the distribution of the Earth’s climate.

We were given time to reorganize the points that we came up with in the previous lesson into a more coherent answer that we want to present to the class. After that was done, some of the groups were called upon to present their answers. One thing that I learnt from the presentation of the answers was that there was a need to be organized. Most of the answers to the questions that are asked in geog are already known to us, thus what differentiates the better answers from the rest is how well they are organized. Organizing the answer properly also helps us to ensure that the answer is logical and is answering the question.

For the question that asked to explain the distribution of the Earth’s climate, the explanations given by the various groups were sort of summarized on the whiteboard.
The climate is generally distributed along the latitudes, as can be seen from the horizontal bands along the Köppen-Geiger map. In general, as we move from the equator to the poles, it tends to get cooler. This is due to the spherical shape of the Earth. The spherical shape causes the radiation from the sun to be spread out unevenly across the Earth. At the equator, the radiation would be more intense as compared to the poles, where the radiation will be forced to spread out over a larger region. Thus, there will be a higher temperature around the equatorial regions. However, there are also abnormalities as the latitudes are not the only factor affecting the climate of the region. The altitude, for example, would be one of the other factors. As the altitude gets higher, the cooler the temperature gets. This is why the Andes mountain range, the Himalayan Mountain range and the Tibetan Plateau are of the polar climate, despite them not being at the poles.

I’m not sure why deserts have a higher temperature than the equatorial regions (since it is closer to the poles than the equator) so can someone please explain that part to me?

The next question was sort of left unfinished, because the different groups were sort of like attempting to simplify the definition of the word ‘seasons’ (although I seriously think that the explanation got much more complicated in the end).

I think that we should not memorize definitions without first understanding it because it would be quite pointless. Furthermore, memorizing will only make things more difficult for us. When we understand the terms/concepts, we will be able to explain them without having to memorize them, thus we will not need to spend hours trying to soak up all the info in the various notes and textbooks.

Well, that’s about all. Byebye! =D

Minh - 23th Feb - Distribution of Climate.

Basically during today lesson, we had to try to answer the question: "Explain the distribution of the Earth's Climate".


As usual, we broke the question into smaller parts and asked questions about every single one first, rather than diving in an ocean of info without knowing what exactly that we need. I realised that even simple questions matter much. We all thought about how the climates are distributed without questioning what "Climate" and "distribution" themselves mean. Questioning and answering those simple things really help us simplify the problem. "Climate" actually refers to how wet and warm the place is, therefore factors affecting the distribution of Climate must be those that affect the temperature and the wetness of the place. Cool! The problem has been narrowed down!



Next, the class was divided into two sides as you all knew. I fell to the season variation side. Our objective is to study why there are seasons on Earth ( I'm feeling that our side is actually answering the temperature half of the question ). And now, using all the progress that my group has made today, I would explain for you why there are seasons on Earth.




Firstly, seasons refer to different periods of the year when the temperature of each period is generally different from each other. 4 seasons Spring, Summer, Autumn and Winter nicely fit in a cycle of one year. Summer refers to the period when the temperature is highest throughout the year, and Winter refers to the period when the temperature is lowest. Spring and Autumn are rather intermediate period between Summer and Winter so the temperature at those time is in between that of Winter and Summer. Another thing to take note is that Spring comes after Winter and before Summer; Autumn comes after Summer and before Winter. Sounds simple, right?



So basically we differentiate seasons based on the temperature. And, as we all know, the temperature of a place generally propotionates to the amount of Sunlight received by that place. Therefore, the Sun has to be somewhat responsible for the distribution of heat on Earth throughout the year.




However, after studying the causes of season variation on Earth, I figured out that the REVOLUTION of the earth around the Sun and the TILT of the earth actually play important roles in causing season variation. And now I will explain to you with a simplified version of the picture that you can find in the notes itself.

First I shall explain a little bit about the picture.

The fish-ball like thing is actually our Earth in different position around the sun, and you should know that the Earth takes 1 year to travel 1 round in its orbit around the Sun. Therefore, the position of the Earth at a point of time is the same as its position one year later. And you also know that the Earth TILTs at an angle of 23.5 degrees with respect to plane that contains its orbit around the Sun. The yellow colour represents the part of the Earth that receives sunlight and blue represents the part of the Earth which does not. The equator represented by the red line divides the Earth into two halves, called North and South HEMISPHEREs.

Okay, now we have enough info to explain season variation. Let's put them together. As you can see, when the Earth is in the right-most position, which corresponds to 21-22 December, you can see that the South Hemisphere (S) generally receive more light than the North Hemisphere (N). And considering the Earth's "free body diagram" in this position, there are much more interesting things that you can see.


In the "free body diagram", the two tiny violet dots represent the two points on Earth which are symmetrical about the equator. As the Earth rotates, the two dots move along the two green lines with the same speed. On the diagram, you all can see that the dot in the South Hemisphere spends more time (More than 12 hrs a day) in the yellow region which is daytime while the dot in the North Hemisphere spends more time (More than 12 hrs a day) in the blue region which is night time, therefore the temperature the South hemisphere is generally higher than that of the North hemisphere and reaches its peak. Therefore, It's summer in the South Hemisphere and Winter in the North Hemisphere.


As the Earth revolves around the Sun for one more quarter of a year, to the second position on 21-22 March, the difference between daylength and nightlength becomes smaller and smaller and finally equal to each other. The temperature is generally the same in the two hemispheres. Because the daylength in the South Hemisphere is generally shorter than previously, therefore the temperature drops with comparison to the 21-22 December point and becomes mild. Similarly, the North hemisphere generally becomes warmer. Hence, on 21-22 March, It's Spring in North hemisphere and Autumn in the South hemisphere.



From here, you can figure out the rest, right?



The 23.5 degrees tilt of the Earth is very important for season variation. If this tilt does not exist, there would not be any difference between daylength and nightlength throughout the year at any point on Earth, hence no seasons.



However, there are much more interesting things than the season variation alone. By shifting the green line along the direction perpendicular to the equator, we get another result that the places near the two poles would have greater difference between the duration of daytime and night time during Winter or Summer and people living around the equator do not have to worry so much about the variation of daylength and nightlength because they have 12hrs of daytime and 12hrs of night time throughout the year. This helps us explain why the temperature of places near the equator varies very slightly as they receive a consistent amount of sunlight throughout a year.



And for the places which is at 66.5 degrees or beyond, there is an interesting phenomenon that a 24 hours or longer daytime/ night time can occur. And at the two extremes, the people who live near the two poles have possibly experienced a period of 6 months with, or without the Sun. You can try to explain this fact using what I've told you previously in this entry. Haha. Doing Physical Geog is fun, right?!?



Basically that's what I've got so far. We've gone through what seasons are, the key factors that causes season variation and the mechanism behind season variation.

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After diving into the pages full of words, I realised that the best way to learn something is to try to visualize it!!! So actually I focus on the picture first and even redraw them all so that I can imagine what is happening. And it was actually very effective because it took me only 15 minutes to digest the content in 8-10 pages of the handout. And after you've understood the thing, try to rehearse everything by your own words. By doing so, you would construct a system where everything has its own place and its own roles, hence reduce the amount of work that your memory has to carry out. Moreover, after you put everything in a complete system, actually you would realise that there are many unnecessary things that you can ignore. One more time, you can minimize the amount of info that our limited memory has to store. Personally I think that's the most effective way to study for me.

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Yawn!!!

I Think I SHOULD and MUST go to bed now.

Tmr Training 6.35 a.m, horrible.

Save me, God.

And all the best, Chandel (kidding only why so serious?).

Post for 20 Feb lesson: The Climograph (Victoria Lim)

Today’s lesson was a revisit on climographs. From the previous lesson, we assembled into our groups to work on various climographs and presented our answers.
We went through again, how to describe a climograph. Most importantly, we have 2 main areas to cover, how warm a place is and how wet.

For both areas, we have to mention the magnitude, which includes the highs and the lows, as well as the distribution – the range. I learnt that apart from merely plucking numbers from the climograph, and trying to impress with our knowledge of statistics, we must, most importantly, interpret the data. The description is what is the core of the answer is, and it helps to use a variety of vocabulary to describe them. From scorching temperatures to freezing colds, intense rainfalls, to droughts. Additionally, we must be able to conclude from all these information, the general pattern of the climograph, thus giving us a good idea of the climate in that region.

The general pattern of a climograph can tell us many things, for example if the area experiences seasons and from which we can approximately infer the location of the area if we have to. In general, I noticed that climographs of regions in the northern hemisphere generally came in the shape of an ‘n’ (the temperature part at least), while countries in the south such as Santiago and McMurdo Station had climographs in a ‘U’.

This is because the northern hemisphere such as US and Russia experiences winter in the Jan/Dec period, with summer in mid-year, hence temperatures follow the n shape with approximately the highest temperatures in Jun. On the other hand, temperatures in the southern hemisphere experience the seasons in the opposite pattern as the north, having temperatures dipping lowest in winters in mid-year, hence giving rise to the U shape. Personally, I find this rather useful as it makes sense and indeed does help me recognise the general patterns. To add on, equatorial countries usually have rather stable temperatures, so their climographs will be rather flat, so called.

Something else which was brought up in class was that in certain countries, the pattern of rainfall followed the trend of temperatures. I’m guessing this is due to higher temperatures resulting in more evaporation leading to higher rainfall. But again, I suppose this does depend on many other factors such as the winds as well as location, so this trend might not hold true all countries.

One last thing I learnt from class today was to be careful not to mention things that cannot be explicitly inferred from the climograph. For example wind patterns cannot be seen from the average climograph and mentioning it in one’s answer will be almost suicidal. So, as the rule of the thumb, just work on whatever’s given in the question.


I guess that’s all :)

Victoria Lim

Hazel Goh

So here's my post for Monday's geog lesson. :)

We talked a lot today about the climate and weather. We always want to know if it's wet or warm in a particular area. There are many ways to describe how wet or how warm a place is! Take for example, descriptions of warmth are, hot, cold, freezing etc. And the descriptions for wet are very wet, damp, mild etc. To add on, how wet a place is depends on the amount of rainfall and the precipitation in that particular area. Snow is not a type of rainfall, but it is a type of precipitation.

Then we watched a video! Bill Nye the science guy. It was a really funny but detailed video! :) It talked about the Earth having many different climates, and covered mostly by water. Different kinds of living things have found their way to adapt to the surrounding climates. Mountains have a big effect on climate, and can divide areas into two different climates, one side warm, and the other side wet.

After that, we learnt about the climograph! :) We were grouped into groups of 2/3s, and then made to evaluate the climographs. When we are doing climographs, we have to always read the title first! So that we would know where the location is. We also have to pay attention to the units, as the units are not standard across the countries. A climograph is a measure of the temperature/precipitation for the year in a particular location, measuring how warm/wet is the area. When evaluating the climographs, we have to look out for the magnitude and the distribution of the temperature and weather. The distribution includes the range (is there any fluctuations?) and the seasons (when is it warm/cool? How many seasons?). We have to describe the general pattern of a climograph via the temperature and precipitation!

When describing a climograph, we have to check out for

• What are the general patterns?
• Any special abnormalities? (Eg, suddenly going out of pattern)
• Is it hot/cold?
• Are there any seasons?
• When is it wet, mild or dry?

AND, we have to be concise! Write as little as possible, and don't be too naggy and long winded! So here's an example of a climograph! :)


For the last part of the lesson, we looked at the latitudes and longtitudes of the world map! :D Climate is affected by location, which is the longtitude! And the world map is sorted out by climates and temperatures by looking at the different coloured areas.

So that's what we covered in on Monday! :) It was really enlighting, watching the video of Bill Nye. It was rather funny, and it showed us how to learn geography in a less boring way! Plus, learning to read the climograph was something new and rather interesting!

Eugenie Foo

HELLOHELLO! :D
Today we had a long lesson full of information! So everybody, here it goes!

We did alot of things today and it includes the cloud-making experiment and learning the different types of rain. Firstly, the coke bottles! Before we started on the experiment, Mr Heah revised water cycle, also known as the hydrological cycle, and he revealed that we would be "making clouds" inside the coke bottles. Mr Heah gathered us around the teacher's table and he demostrated "making clouds". I'm sure everyone was amazed, and so was I! It was cool, to see clouds appear and disappear before our eyes. For the experiment, we needed a 1.5 litre coke bottle, and a little bit of water in the bottle. All we had to do was to extinguish a matchstick, trap the smoke from the matchstick in the bottle and cap the bottle up. Then, we had to squeeze the bottle and release it continuously. While squeezing and releasing the bottle, we see a phenomonen! x) We notice that when squeezing the bottle, the bottle is clear inside. However, when releasing the bottle, the inside of the bottle turns cloudy! Seeing this, we have just "made clouds"!

After the experiment, Mr Heah wrote two questions on the board,
1. Why is there a need to squeeze the bottle?
2. Why is the smoke needed?

1. Firstly, how do clouds form? Water vapour must become water droplets in order to form clouds. When we squeeze the bottle, the volume of the bottle becomes smaller, and there is a higher pressure in the bottle, and the temperature is high, and water remains as water vapour. When we release the bottle, the volume of the bottle becomes larger, and the pressure becomes lower, the temperature is low, and water droplets form! Therefore we squeeze the bottle to allow the pressure to change and cause water droplets to form as described above.

2. Now why is the smoke needed? Water droplets are really really small and therefore they only collide and bounce off. To make water droplets coalesce into a visible cloud, there is a need for a surface. And in the case of the experiment, aerosols (eg. smoke) serve as a condensation nuclei, which allow water droplets to coalesce into a cloud, therefore smoke is needed.

(:
Now, the different types of rain! There's 3 types, namely the relief rain, the frontal rain, and convectional rain. We were separated into 6 groups and were given 5 minutes to explain the various types of rain. This is what we learnt about the 3 types of rain:

1. Relief rain.
As the name suggests, this got to do with the relief of a mountain. As moisture-laden air approaches the mountain ranges, the relief of the mountain forces air to rise, and adiabatic cooling (air forced to rise, expand and condense, and water droplets form) occurs, and clouds form, and eventually, rain falls. The unique thing about relief rain is that all rain would only fall on the leeward side of the mountain. Why? At the windward side of the mountain, there is less moisture, and air sinks. As the air gets warmer, condensation no longer occur, and no clouds would be form, thus no rain.

2. Frontal rain.
As warm air meet cold air OR as cold air meet warm air, they do not mix. Instead, the denser cold air would force warm air to rise, and adiabatic cooling occurs, and clouds form, and eventually, rain falls. The unique thing about frontal rain is that this type of rain can only be found at temperate regions.

3. Convectional rain.
Heat from the sun heats up the ground and ocean, causes the air to get warmer (lower density) and rise, adiabatic cooling occurs, and clouds form, and eventually, rain falls. The unique thing about convectional rain is that it only happens at tropics and equatorial regions, and it would only occur in the day time, from afternoon to evening.

Yay, that marks the end of the lesson! It was an enriching lesson, and I never knew there was different types of rain! I have learnt how to "make clouds". I have also learnt what happens before it rains, and most importantly, I have learnt to use the correct terms in replacement of the layman terms, such as adiabatic cooling, coalesce, aerosols! Till next time, haha. :D

Comments: (here, name at bottom)
The most important thing to take note is the process how the air is forced to rise up. And the thing following it is just adiabetic cooling, clouds form and rain. The names of the types of rain also suggest what forces the air to rise. RELIEF of the mountain, hot air rises at its FRONT(AL) with cool air, and hot air rises up simply because of CONVECTIONAL air flow <- Shorter and easier to memorise. ( by Minh ).

Charmaine Khoo

Reflections for Monday 9th February Geography lesson

I’m really sorry for the delay in submitting this reflection, I was not feeling well last night (went to the doctor's) so I did not have time to post. Here’s my reflection:

During today’s geography lesson, we watched the video “An Inconvenient Truth” by Al Gore. The main gist of it revolves round the topic of the increase of carbon dioxide in our atmosphere leading to global warming leading to adverse effects on Earth. I really enjoyed watching the video; its visual aids (such as graphs) helped to bring the message across very effectively.

The atmosphere is very vulnerable, very thin, and we humans are absolutely capable of changing its composition. As shown in various graphs in the video, the level of carbon dioxide produced into the air and temperature of earth are constantly rising and have risen significantly much faster over the last 10 years.

Glaciers are melting at a rate faster than anyone can imagine now, which brings detrimental effects such as the polar bears having to swim miles to find ice as depicted in the video and ocean waters absorbing the sun’s rays faster than before. This is indeed very worrying. It is good that we are exposed to such a phenomenon of the Earth. While we are cooped up at home in Singapore, we do not know what takes place in other places of the world such as the North and South Poles, where gigantic chunks of ice are melting away each day. How can we just watch our Earth fall into the hands of global warming like that and not do anything? What can we do to reduce the amount of carbon dioxide being released into the air?

I remember Al Gore talking about the carbon dioxide level in history, for as long as it was recorded. Earth experienced 7 ice ages, 650,000 years recorded and the carbon dioxide level has never exceeded 300 million parts (that’s how it was measured). Today’s carbon dioxide level has hit way, way above any record in history. As my eyes traced the line extending upwards, I was shocked at how sharp the gradient of this line is. The carbon dioxide level is increasing at too fast a rate for us! We have to do something drastic about this before all the remaining ice melts during summertime in 30-50 years.

He claims that there are 3 reasons for the possible collision of the world in future. The first is increase in population over generations, which put pressure on the supply of food, water and other resources as these have to be increased to meet the demands. Secondly, old habits + new technology = dramatically altered changes. Lastly, it is the sudden jolt to be aware of danger, as illustrated by the frog humping out of hot water. Do not wait till tomorrow to start making attempts to save the Earth, our home. We may not directly feel the effects of it now and thus not care much. However, we have seen the truth for ourselves in the video. Many countries/ states are drowning because of the excessive melting of ice into water around it. We have to start making the conscious effort now.

When the Earth’s overall heat gain is greater than its' heat loss, as being experienced now, what will happen? This leads to the question posted to us: To what extent should we be concerned about carbon dioxide emissions?

Comments: (here, name at bottom)

Chandel Tan

Hello people:)

so it's finally my turn to blog about my geog reflections. it's kind of pressurising seeing how the previous 3 people all had uber long blog posts. HAHA. i shall try to make it long. and well, easy to digest. ok. so here goes:

today, we talked about THERMODYNAMIC EQUILIBRIUM, meaning that whatever heat gained from the sun to the earth will be the same amount as whatever heat lost.

we also had this really really short discussion on how heat transfer is made up of 3 mediums - conduction, convection and radiation. yes yes, i know we've already learnt that in sec 2.

Also, we touched on the electromagnetic spectrum, a 'bar' made up of the colours of the rainbow. so how do you actually intepret the electromagnetic spectrum? well, the lower the energy rays, the longer the wavelength on the spectrum. and as you all know, the coulours of the rainbow are in this order: RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET.. yes.. so any wavelengths longer that the RED coloured part will be hereby known as INFRARED RAYS. (like how phones used to have infrared.. but i think these phones are pretty outdated already) and.. wavelengths shorter than the VIOLET coloured part are known as ULTRAVIOLET RAYS..

just for your information, heat gained from the sun is know as short wave radiation (which also symbolises a gain in heat on earth's surface). and heat produced from the earth is also called long wave radiation.. (meaning that heat is lost from earth)

apart from these facts, we also learnt to draw the diagram to depict the global shortwave radiation cascade. although it was pretty confusing in the beginning, we soon learnt the method of drawing the diagrams. the trick, however, is simply to read the instructions step by step. Personally, i feel that this simple method does wonders when one is truly clueless and confused as you are taken to approach the problem a step at a time. for example, in math, you don't usually go straight into the final statement and come up with the answer. you analyse it, then you try to find the right formula or something. then you solve. haha. yes.. it's the same thing for drawing of such diagrams.

we also did some group work during the lesson today, since we were made to come up with a diagram as a group. so we had some interaction with our classmates during geog lesson today. I have to say that many brains put together far surpasses a sole opinion since i not only clarified my doubts of the diagram's concept with daryl, but also managed to see how the diagram should more or less look like, since each of us contributed in one way or another during the illustrating of the diagram. Should I have tried to attempt it all by myself, I would not have cleared the question in my head, and might not even have figured out how the diagram should have been drawn.

In a nutshell, within today's 1 hour period, I not only acquired new knowledge, but also realised the importance of going a step at a time to acheive utmost success, and also how crucial it is to work as a team. I learnt a lot indeed.

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Sara Chan

The entire world operates as a system, and in order to maintain this system, regulatory forces are required to maintain balance. This may sound obvious, and scarcely in need of being repeated, but I feel that we do not quite register the significance of this. This balance is essential, it plays a crucial role in our continued existence (just like the atmosphere). Our lives, our future, our very existence is dependent on this balance. How ironical it is that we, as human beings dependent on this delicate balance are doing our utmost to upset this balance, an act which, should we succeed, can ultimately end only in the annihilation of ourselves.

When watching the video we saw in class today, the first thing that came to my mind was that our earth is beautiful. Isn't it amazing how the simple presence of the atmosphere has transformed the once (theoretically) barren planet into the gorgeous paradise we see around us today? (Or the paradise we would see if we didn't live in the concrete jungle of Singapore.) What a wonderful job the stromatolites (was that spelt correctly? stromatolites are the first life forms on earth, bacteria, the first to photosynthesize and produce that incredible life giving gas: oxygen) did of turning that "witches brew" of noxious fumes into the vibrant, life-supporting world of today.

The Earth is simply perfect for human survival, or perhaps I should say was. The composition of air for example, 21% oxygen, 78% nitrogen, 0.03% carbon dioxide and 0.97% sundry other gases, is completely ideal for human habitation. Too much oxygen would lead to the horrible anguish of lung damage as oxygen is a highly reactive element, while too would result in a slow suffocating death. The key then is balance: neither too much nor too little. Take carbon dioxide, along with other greenhouse gases as another example. Too little and we would freeze to death, but any more would lead to global warming. As we saw in the video today, global warming sets off a chain of other events. Apart from the obvious rise in temperatures across the globe, and the subsequent melting of the ice around the world, the rise in ocean levels and all the other problems brought on by global warming, there is also the melting of the permafrost in Siberia, releasing copious amounts of methane into the atmosphere. As an extremely potent greenhouse gas, the drastic increase in methane would lead to a great rise in global warming: a downward spiraling cycle where more global warming causes the release of more methane which in turn causes a rise in global warming and so on. How quickly things spiral out of control once we tip the balance! This balance we depend on is indeed delicate. Delicate and precious.

Another thing we learnt to day was how to analyze questions, a skill that will surely be useful, not only in Geography, but also in English, Chinese, MI, and possibly all of our other subjects as well. Breaking down the question does indeed help you to understand exactly what the question is asking for, and, consequently, makes it a lot easier to answer.

The last thing we covered today would be the carbon cycle, in which we once again made use of the nifty method of mind-mapping. Another thing that proves how perfectly the world is for survival: the way the carbon circulates. And another example of how humans are demolishing the earth through deforestation and whatnot. It may take some time to get used to mind mapping as opposed to memorizing all those facts and regurgitating them when the exams loom over us, but I'm sure as time goes on we will find it much easier. Not to mention we would probably die if we attempted to memorize everything we're learning for Geography.

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