Saturday, February 28, 2009
Geography lesson, 27th February 2009Today, our Geography lesson is quite exciting.
Once again, Mr. Heah told us about the better way to study geography. As you all know by now, memorizing is strongly discouraged. But the very fact is that you will still need to sit for exams. So Mr.Heah said the most effective way is to study using your logical/critical thinking (study the Earth as a system) to generate your own knowledge.
After that, we came back to answer the two questions brought by Mr.Heah last lesson
1/Explain the distribution of Earth’s climate
Once again, splitting up the questions to get the main ideas is important. There are several questions you need to think about before you can attempt to find the answer for the main question (as mentioned by Sue-ann in the last post).
However, the most fundamental question you need to think about is what is the Earth’s climate distribution. And I do think that the more important thing is to find out the “how” behind the “what”.
If you look at the World Map of Koppen-Geiger Climate Classification given, you should notice that there is a banding pattern in the climate distribution. This banding pattern is actually along the altitude and is symmetrical along the equator. So, there are some more questions we need to think about before we can reach the final answer.
1. Why is climate different in different regions of the world ( polar, temperate, tropical, temperate, polar )
2. Why is the climate distribution patterned the way it is?
My group came out with several single words to answer those questions such as radiation, heat, shape, tilt, etc. However, we then look at specific features of each type of climate over certain regions. The climate is actually identified to be warmer at equator and cooler as approaching to polar regions. Does it have any link to radiation energy from the Sun? We know that the intensity of radiation has nothing to do with the distance from the Sun to certain region that receives the energy. However, over larger distance, the energy will be diffused and by the time it reaches the surface, it will be less intensive. Here, looking back at our Earth, the equatorial region receives the most intensive radiation from the Sun. Thus, this region is always warmer compared to the polar regions which are farer from the Sun ( by the time radiation reaches those regions, it is less intensive as it has been diffused over space ). Once again, we need to think. Why is it so, why does equatorial region receives most intense radiation from the Sun while polar regions are farer from the Sun, thus get less intense radiation? It is so simple that the answer can be expressed in only one word. It is because of our Earth’s SHAPE. (circular)
So all in all, the answer to a the question actually lies in one key word : SHAPE
2/Why are there seasons?
What are seasons in the very first place?
The most important thing we should know about season is the change of weather (ex, from low to high temperature and vice versa)
Here, we need to look at the climographs given, it is notable that the change occurs in the middle of the year.
Some may ask are the seasons results of changes in the distance from the Earth to the Sun? No, they are actually not.
In our lesson today, we learn that our Earth spins on a tilted axis (this axis is an invisible axis through the center of the Earth) once every 24 hour. That’s why there are day and night.
In addition, the Earth revolves around the Sun once every 365.25 days. As such, the tilt of the Earth causes different regions of the earth to point towards the sun (over specific periods of time). This causes different amounts of sunlight to reach the same surface area of the Earth throughout the year. The different amounts of sunlight lead to different weather at this location
There are seasons because the Earth’s axis of rotation is tilted 23 degrees. In June, northern hemisphere is tilted towards the Sun, so the sunlight has the more direct path to the Earth surface, thus, there are more hours of sunlight during the day. As a result, it is summer in northern hemisphere. Meanwhile, in southern hemisphere, the sunlight has to go a longer path to the surface and the days are shorter in June. So, it is winter in southern hemisphere.
So, basically, looking back at the question and the detailed answer I have written, the main point lies in the word “tilt”
All in all, answers for many questions can be expressed in one word or few. The important thing is that you need to use those few words to generate your own complete answer from what you already know. This is a better way of learning.
So that's about it :)
Chi
Monday, February 23, 2009
Today we had a short lesson. We learnt a lot but very little. A lot of concepts and ideas and theories, but very little put in words. This is something I think we need to brush up on. How to express our answers in words.So, the first question posed to us was:
Explain the distribution of the Earth's climate.
Splitting the question up, we look at the words distribution and Earth's climate respectively.- What is distribution?
- Which areas?
- Why?
- What is climate?
- How many types/kinds of climate?
- What is the difference (how to tell them apart?) ?
From what we have learnt so far, we are already able to answer question 1. What is climate? It is how warm and how wet a particular place is.
We were then splitted into groups according to our birthdates! Interesting way of grouping. Some of us were to answer the question above, and others were to answer the question below.
Why are there seasons?
For my group, we came to understand that seasons are caused by the 23.5 degrees tilt of the Earth on its own axis, AND the revolution about the Sun. The amount of insolation the Northern hemisphere receives from the Sun determines the seasons it is going through.
During the period of June, the incoming solar energy is the greatest in the Northern Hemisphere, thus it is going through summer. Looking at your notes, Figure 2-11, the diagram shown is a clear representation of the tilt towards the sun in June. It is clear that the Northern hemisphere receives most insolation from the Sun then. Vice versa for the winter time in Dec for Northern Hemishpere.
As the year goes by, the rotation of the Earth on it's own axis plus the revolution around the Sun causes Autumn , Winter, Spring to follow as well.
When Spring and Autumn is in place, the position of the Earth towards the Sun allows equal amounts of insolation for BOTH hemispheres. though the position of the Earth during Spring and Autumn receives same amount of insolation, it is different because when Summer becomes Winter, (warm to cold) leaves dry up start to fall: Autumn. When winter becomes summer (cold to warm) leaves are given more warmth and all life needs warmth to grow therefore Spring comes.
So far this is what we have concluded. Coreect me if i'm wrong and, if your group is ready to share your view on any of the 2 questions, please comment. *winks*
Sue-Ann. [:
Friday, February 20, 2009
Climographs
We revisited climate and precipitation over again today. There’re just a few main points that we need to remember, in order to describe climographs accurately and concisely, so here it goes.Climate: Tropical (Arid), warm or cold temperate, polar (tundra)
To differentiate warm or cold temperate countries, warm temperate countries have warmer winters and summers whereas cold temperate countries have cooler summers and winters.
When describing climate, we need to say:
a) How warm it is–
This is measured in terms of temperature (not a description). Humidity is NOT included.
BE SPECIFIC: Is it freezing cold, cold, cool, warm, or sweltering hot?
After we focus on magnitude, focus on the distribution throughout the year (compare to seasons). Is it high, low or moderate? Then, we focus on the range. Is it small or large?
b) How wet it is—
This is mentioned in terms of how much liquid is precipitated. We use the term precipitation as it includes snow, hail, etc, whereas rainfall does not. Move on to describe precipitation; is it dry(draught season), or wet(monsoon)? Is it even, or uneven?
Then, we can see if there is a pattern between precipitation and rainfall. In countries such as Tokyo, temperatures and precipitation increase at decrease at around the same periods. If there is none, then nevermind.
Additional point: To describe temperature or precipitation, we put anomalies aside in order to determine the precipitation kind or temperature type. Always remember that climate is based on how wet, and how warm a country is.
My opinion: I think a good climograph description should be able to reflect the temperature and precipitation in a country in someone’s head if there is no climograph.
Barrow, Alaska, USA
- Generally freezing cold and dry.
- Extremely low rainfall, with peak periods of July to October at 20mm. Mostly, rainfall during the year barely reaches 10mm.
- Temperatures are usually sub zero (below zero) with warmer months from June to September at 1°C to 5 °C, and cold months occur in December to February at around 28°C.
- Warmer and wetter periods exist from July to October, whereas Colder and drier periods from December to February.
- Climate is typical of a Polar tundra.
a) How warm it is–
This is measured in terms of temperature (not a description). Humidity is NOT included.
BE SPECIFIC: Is it freezing cold, cold, cool, warm, or sweltering hot?
After we focus on magnitude, focus on the distribution throughout the year (compare to seasons). Is it high, low or moderate? Then, we focus on the range. Is it small or large?
b) How wet it is—
This is mentioned in terms of how much liquid is precipitated. We use the term precipitation as it includes snow, hail, etc, whereas rainfall does not. Move on to describe precipitation; is it dry(draught season), or wet(monsoon)? Is it even, or uneven?
Then, we can see if there is a pattern between precipitation and rainfall. In countries such as Tokyo, temperatures and precipitation increase at decrease at around the same periods. If there is none, then nevermind.
Additional point: To describe temperature or precipitation, we put anomalies aside in order to determine the precipitation kind or temperature type. Always remember that climate is based on how wet, and how warm a country is.
My opinion: I think a good climograph description should be able to reflect the temperature and precipitation in a country in someone’s head if there is no climograph.
Barrow, Alaska, USA
- Generally freezing cold and dry.
- Extremely low rainfall, with peak periods of July to October at 20mm. Mostly, rainfall during the year barely reaches 10mm.
- Temperatures are usually sub zero (below zero) with warmer months from June to September at 1°C to 5 °C, and cold months occur in December to February at around 28°C.
- Warmer and wetter periods exist from July to October, whereas Colder and drier periods from December to February.
- Climate is typical of a Polar tundra.
Santiago, Chile
- Santiago has a warm temperature climate throughout the year. The temperature has a large range from 8°C to 20°C. The highest temperature is 20°C in December to February, followed by a steady decrease in temperature to a low of 8°C. After this decrease, temperature steadily rises back to 20°C.
- Santiago receives an uneven amount of precipitation throughout the year. It is dry during summer and slightly wet in winter, autumn. The range is from 0mm to 9mm. This precipitation differs from the temperature graph in a way that when temperature is high, rainfall is of a minimal amount. Conversely when temperature is low, rainfall is rather high. It increases to 9mm in June, followed by a decrease to 0mm in December, which lasts till about March.
- Climate is typical of a hot, arid one.
- Santiago has a warm temperature climate throughout the year. The temperature has a large range from 8°C to 20°C. The highest temperature is 20°C in December to February, followed by a steady decrease in temperature to a low of 8°C. After this decrease, temperature steadily rises back to 20°C.
- Santiago receives an uneven amount of precipitation throughout the year. It is dry during summer and slightly wet in winter, autumn. The range is from 0mm to 9mm. This precipitation differs from the temperature graph in a way that when temperature is high, rainfall is of a minimal amount. Conversely when temperature is low, rainfall is rather high. It increases to 9mm in June, followed by a decrease to 0mm in December, which lasts till about March.
- Climate is typical of a hot, arid one.
Bombay, India
- Bombay is HOT, and has a fairly high temperature which is constant throughout the year with monthly average temperature between 23°C and 30°C.
- Bombay has a very uneven distribution of precipitation. During its wet season between June to September, it receives an intensive precipitation, especially in the month of July. (Approximately 650mm.
NOTE: In some countries, temperatures rise, as well as rainfall. However, this is just a trend, not that it is supposed to be that way.
- In September, there is a sharp drop in precipitation, followed by the rest of the months in the year (November to March), in which it is extremely dry and receive on average a precipitation below 10mm. This is very low, and sometimes so low that it hardly receives any rainfall.
- This climograph is typical of a tropical monsoon climate.
- Bombay is HOT, and has a fairly high temperature which is constant throughout the year with monthly average temperature between 23°C and 30°C.
- Bombay has a very uneven distribution of precipitation. During its wet season between June to September, it receives an intensive precipitation, especially in the month of July. (Approximately 650mm.
NOTE: In some countries, temperatures rise, as well as rainfall. However, this is just a trend, not that it is supposed to be that way.
- In September, there is a sharp drop in precipitation, followed by the rest of the months in the year (November to March), in which it is extremely dry and receive on average a precipitation below 10mm. This is very low, and sometimes so low that it hardly receives any rainfall.
- This climograph is typical of a tropical monsoon climate.
Tombouctou, Mali
- Tombouctou, Mali has a warm climate with temperatures ranging from 20°C to 33°C throughout the year. Temperatures increase steadily towards midyear (Jan) from 20°C to 33°C in June, and decreases from mid year to year end (Dec) from 33°C to 20°c.
- Tombouctou, Mali has a dry climate with rainfall less than 50mm for most of the year except during the mid year (June to Sept) when it gets slightly wetter with precipitation of approx 80mm.
- This climograph is of a tropical, arid climate.
- Tombouctou, Mali has a warm climate with temperatures ranging from 20°C to 33°C throughout the year. Temperatures increase steadily towards midyear (Jan) from 20°C to 33°C in June, and decreases from mid year to year end (Dec) from 33°C to 20°c.
- Tombouctou, Mali has a dry climate with rainfall less than 50mm for most of the year except during the mid year (June to Sept) when it gets slightly wetter with precipitation of approx 80mm.
- This climograph is of a tropical, arid climate.
London, England
- While temperatures in London tend to rise and decrease in the year, rainfall tends to remain around the same amount.
- London has a cool climate with a steady increase in temperature from Jan to july (approx 5°C to 18°C). When temperature reaches its peak in July, it starts decreasing to a temperature of 5°C from July to December.
- London has a relatively even distribution of precipitation throughout the four seasons (approx 50 to 70mm.)
OR
- You could say: London has a rather small range of precipitation throughout the year.
- This climograph is of a typical warm temperate climate. (warmer summer and winter).
- While temperatures in London tend to rise and decrease in the year, rainfall tends to remain around the same amount.
- London has a cool climate with a steady increase in temperature from Jan to july (approx 5°C to 18°C). When temperature reaches its peak in July, it starts decreasing to a temperature of 5°C from July to December.
- London has a relatively even distribution of precipitation throughout the four seasons (approx 50 to 70mm.)
OR
- You could say: London has a rather small range of precipitation throughout the year.
- This climograph is of a typical warm temperate climate. (warmer summer and winter).
Tokyo, Japan
- Japan has a relatively cool climate throughout the year. From Jan to Aug, there is a steady increase of temperature of approximately 4°C to 26°C. Temperatures reach their peak at around August, followed by a stable decrease to approximately 6°C.
- Japan is relatively wet—its precipitation mostly averages from 100mm to 200mm. It is rather high in the months of June, September and October, but precipitation is fairly low from November to February comparatively. In months such as July and August, precipitation drops from June, then rises in September, where it is supposedly supposed to increase in relation to the steady upward trend. The precipitation graph tends to follow the temperature graph.
- This climograph is typical of a warm temperate climate.
- Japan has a relatively cool climate throughout the year. From Jan to Aug, there is a steady increase of temperature of approximately 4°C to 26°C. Temperatures reach their peak at around August, followed by a stable decrease to approximately 6°C.
- Japan is relatively wet—its precipitation mostly averages from 100mm to 200mm. It is rather high in the months of June, September and October, but precipitation is fairly low from November to February comparatively. In months such as July and August, precipitation drops from June, then rises in September, where it is supposedly supposed to increase in relation to the steady upward trend. The precipitation graph tends to follow the temperature graph.
- This climograph is typical of a warm temperate climate.
Brueno Aires, Arg
- Brueno Aires has a moderately high range of temperature varying from 9°C to 23°C. The hottest months are from Dec to March where temperatures hit above 20°C. This is followed by a decrease in temperature in the months of march to August, in which temperatures are lowest in June. Subsequently, temperatures then resume with an increase.
- There is a relatively even amount of precipitation throughout the year, of less than 100mm. Dry months exist in the months of May to August of approximately 50mm, and in September to April, precipitation is of a larger amount. The peak is during March, reaching a high of 110mm.
- Brueno Aires has a fairly wet climate.
- This climograph is typical of a warm temperate climate.
- Brueno Aires has a moderately high range of temperature varying from 9°C to 23°C. The hottest months are from Dec to March where temperatures hit above 20°C. This is followed by a decrease in temperature in the months of march to August, in which temperatures are lowest in June. Subsequently, temperatures then resume with an increase.
- There is a relatively even amount of precipitation throughout the year, of less than 100mm. Dry months exist in the months of May to August of approximately 50mm, and in September to April, precipitation is of a larger amount. The peak is during March, reaching a high of 110mm.
- Brueno Aires has a fairly wet climate.
- This climograph is typical of a warm temperate climate.
McMurdo Station
- Fairly constant and low precipitation throughout the year, ranging from 0mm to 10mm. The climate is extremely dry, with sub zero temperatures ranging from approximately -26°C to -4°C. In the months of April to September, temperatures are extremely low as it is during the cold seasons (approx -22°C to -27°C) with moderately constant levels.
- From Jan to April, there is a steep and steady decrease in temperatures of -3°C to 22°C, as it is the transition between Summer and Winter.
- Comparatively, there is also an increase in temperature from September to December, marking the progression between winter and summer.
- This cold and dry climate is typical of a polar tundra climate.
- Fairly constant and low precipitation throughout the year, ranging from 0mm to 10mm. The climate is extremely dry, with sub zero temperatures ranging from approximately -26°C to -4°C. In the months of April to September, temperatures are extremely low as it is during the cold seasons (approx -22°C to -27°C) with moderately constant levels.
- From Jan to April, there is a steep and steady decrease in temperatures of -3°C to 22°C, as it is the transition between Summer and Winter.
- Comparatively, there is also an increase in temperature from September to December, marking the progression between winter and summer.
- This cold and dry climate is typical of a polar tundra climate.
Yakutsk, Russia
- Cool summers and freezing cold temperatures during winters, rather dry all year round.
- Temperature fluctuates greatly, with drastic increases and decreases (large range of temperature/ huge temperature differences at different times of the year.)
- Winter temperatures of -40°C or even slightly below. Summer temperatures are approx 15°C to 20°C.
- As temperature increases, precipitation generally increases.
- Generally, very low precipitations with peaks at 50mm in July, (summer) and with very low levels of precipitation during winter months.
- This climograph is typical of a polar tundra climate.
- Cool summers and freezing cold temperatures during winters, rather dry all year round.
- Temperature fluctuates greatly, with drastic increases and decreases (large range of temperature/ huge temperature differences at different times of the year.)
- Winter temperatures of -40°C or even slightly below. Summer temperatures are approx 15°C to 20°C.
- As temperature increases, precipitation generally increases.
- Generally, very low precipitations with peaks at 50mm in July, (summer) and with very low levels of precipitation during winter months.
- This climograph is typical of a polar tundra climate.
Yea. That's about it. yunwei
Monday, February 16, 2009
CLIMATE GRAPHS.Today’s lesson was rather short and sweet. (:
Basically, to determine :
1. how warm a climate is, we look at the temperature
2. how wet a climate is, we look at the amount of precipitation.
When reading climographs, we convert the amount of precipitation into mm. Note: (1cm=10mm)
There are 3 axis for climate graphs, and JFMAMJJASOND stands for the months in a year.
The line graph tells you the average monthly temperature,
and the bar represents the average monthly precipitation.
Things to note:
1. Always look at the title
2. Look at the temperature and amount of precipitation
MOST IMPORTANTLY: ALWAYS TAKE NOTE OF THE UNITS
Usually what you will be asked to do is to:
1. Describe how warm or how wet a place is.
2. Read temperature and precipitation, and describe what you see.
3. Describe the general pattern(magnitude)
4. Look out for the anomalies
5. What kind of climate does this country have? (Polar/Tropical/Temperate)
Example. Singapore's climate would be tropical, as it is warm and wet.
If countries are less wet than Singapore, we can describe them as mildly wet.
In addition, for countries such as Bombay, their climate would be described
described as very wet due to intense rainfall.
Thats all for now. (:
Cheers!
-grace :D
Friday, February 13, 2009
official rainmaker
Well, friday's lesson started with the question, “What do you remember about the water cycle from primary school? (throughout this blog post, ill mainly be focusing on the red box).
Then we went on to the “cloud in a bottle” experiment and what we observed is that only after adding in the smoke, when the bottle is squeezed, we don't see “clouds” however when we release it we see “clouds.” Yes, you guessed it, its all related to pressure and this is very much like how clouds are formed. But what is the link between pressure, smoke and clouds?
Well, since clouds do not appear in our homes, we can safely say that yes, pressure on earth is higher than that in our atmosphere. Lets say you have 100 units of heat for an ice cube(solid state). Now if I want to make this solid a liquid, I would have to force these molecules apart, as in the liquid state, molecules are further away from each other, this would eventually leave me with less units of heat as the molecules have absorbed the heat energy to move apart. Now think, if I were to make this liquid into a gas, I would have to again force the molecules apart, this time further than before and I am thus left with even less units of heat.
What does all this mean? Well, it is simply that releasing the pressure allows air to expand, and in doing so, the temperature of the air becomes cooler. Thus condensation occurs but clouds do not form because the water droplets are too small. So what happens? The water droplets collide instead of coalescing to form clouds. The air now is super saturated however, the water droplets would group together more easily if there are some solid particle in the air to act as a nucleus. This is where the smoke comes in, thus the cloud only forms when you add the smoke into the bottle. In the troposphere, the solid particles in the air may be in the form of pollution, smoke, dust or even tiny particles of dirt.
We now know how clouds are formed, but do you know how rain is formed? And did you know that there are 3 different types of rain? (well there may be more but we only covered 3 during lesson)
The three different kinds of rain are namely relief rain, frontal rain and convectional rain. Before I carry onto explain how each of these rain is formed I would like you to know what adiabatic cooling is. It is basically a process whereby air is forced to rise,expand and then condense to form water droplets.
Relief Rain:
The unique thing about this rain:
only occurs where there is a really high mountain or a mountain range
only rains on one side of the mountain (the leeward side). It doesn't rain at the rain shadow/windward side. Why? Well simply because there is little or no moisture here, the air then sinks and heats up.
- take a look at the Himalayan and Andes mountains, notice how there are deserts found there.
2. Frontal Rain
NOTE: warm air and cold air do meet but they do not mix, so what happens when they meet? Well, since cold air is denser than warm air, the cold air will sink, forcing the warm air to rise, we then get adiabatic cooling. After which clouds and rain form.
Unique thing about this rain:
only found at temperate regions, because this is where the cold air from the polar regions meet the warm air from the tropical regions.
3) Convectional Rain
Note that for convectional rain, the sun does not heat up the air. What happens is, the sun heats up the ground (land) the land then heats up the air. The warm air then rises and once again we get adiabatic cooling, after which clouds and rain form.
Unique thing about this rain:
found at tropical regions as it is sufficiently warm there.
- normally occurs during the afternoon to evening, why? Well cause thats when the sun is up. It doesn't occur during the day time, as the ground isn't hot enough to heat up the land. But then why is it we experience rain in the daytime sometimes? Well thats monsoonal rain and I'm not about to get into that.
We'll that's basically it. Enjoy! Oh and for those guys who missed out on all the FUN during lesson, here;s a little video, though i don't think you can see much.
meera
Monday, February 9, 2009
Mr. Sunbeam is trapped! :O
So Mr Heah let us watch The Inconvinient Truth by Al Gore today. :D So I shall try to pick out the main points from the video, since some of you *ahemahem* fell asleep during the video! haha. xDSo basically, the video talks about global warming and how it's affecting us. So here's a quick recap on what global warming is (although you should know fully well by now):
The Earth is made up of a thin layer of atmosphere. It's so thin that its like you painting a coat of vanish onto a globe and the atmosphere is represented by the varnish. So you can imagine how thin the atmosphere is in relation to Earth. So when the atmosphere gets thicker, the air composition also changes, which means that more greenhouse gases are in the atmosphere and more heat is trapped! So in the video, Al Gore showed a cartoon to represent global warming and there it is! Heh. xD
So after watching this, you should have a rough idea on why the Earth is getting warmer and warmer.
So Al Gore goes on to explain why there are high and low points on the carbon charts. And this is due to the fact that there are more vegetation in the Northern Hemisphere as most of the landmass is in the Northern Hemisphere. So drung Spring and Summer, the Northern Hemisphere is facing the sun, so the plants will take in more carbon dioxide for photoshynthesis thus causing the carbon dioxide level to drop. Then when it's the Southern Hemisphere turn to face the Sun, the plants release more carbon dioxide due to respiration and a lower rate of photosynthesis. However, there is a steady increase in the amount of Carbon dioxide in the atmosphere over these few years. And so when the amount of carbon dioxide increases, the higher the temperature, as illustrated in the video above.
As Mr Heah always say, there is always a cause and effect for everything. So what's the effect of global warming?
-Glaciers are melting. If you watched the video, it's kinda scary to see the rate this HUGE, GIGANTIC glaciers are melting at.
-Many mountains like the Alps, Mt Kilimanjaro, etc have no more/little snow at the peaks anymore as they are melting at a super fast rate as well.
You may think, so what? This doesn't really affect us, after all we're living in Singapore and those glaciers and mountains are mostly at the other end of the world. But you're wrong! Places like Greenland and West Antartica have lots of land-based glaciers which are starting to melt. And if half of Greenland and half of West Antartica glaciers melt, the sea levels will rise about 20 feet ALL around the world. Thats like ALOT ALOT of extra water. And Singapore being an island surrounded by open seas, we're most likely going to go underwater as well. Places like San Francisco, Beijing, Shanghai will all be affected as well. Billions of people are going to lose their lives cos of global warming.
So I'll just backtrack abit. If you're wondering how those ice glaciers melt so fast, its cos when sunlight hits the ice, 90% of the heat is reflected back to space. HOWEVER, when the sunrays hit the open waters surrounding the ice, 90% of the heat is absorbed, causing the surroundings to get warmer, thus causing the ice to melt at a faster rate. So it is really important for us to come up with ways to stop global warming. hopefully this will help your Geog Essay, which is due next monday, a little. (:
So I'm done summarising (ok fine, it's kinda long) today's lesson. Now i have to write my answer for the geog question on the yellow paper. And if you think you can copy my answer, GET THAT IDEA OUT OF YOUR HEAD NOW! Cos seriously, i don't do well for such questions. But we learn and improve on our mistakes. ;D
Qns: To what extent should we be concerned about the CO2 emissions?
Ans: We should be veryconcerned about CO2 emissions as it has many harmul effects on us.
Firstly, when too much CO2 is emitted into the atmosphere, it will case global warming to happen as the CO2 will trap the sun's heat and prevent it from going back to space and thus, the global temperature will gradually increase. When the global temperature increases even by as little as 1 degree celsius, the ice glaciers at the North and South pole will melt rapidly. This will cause an increase in the water levels all around the world and many places will be flooded.
Secondly, when we emit too much CO2, it will cause Climate Change. Climate Change will affect all of us. Examples of climate change can be seen in the news these days. For example, Melbourne, Australia is experiencing the hottest summer ever with temperatures rising up to as high as 46.5 degress celcius. While in places like China, certain places are experiencing severe flooding while parts are experiencing severe drought. This shows that Climate change has a negative impact on us.
Therefore, looking at the severity of Global Warming and Climate Change caused by CO2 emissions, we should be very concerned at the amount of excess carbon dioxide we're emitting into the atmosphere as it has severe impacts on us and the environment we are living in.
That's all,
-Amelia ;D
Friday, February 6, 2009
At the start of the lesson, Mr Heah did a revision of what we had done last week.
Firstly, he talked about systems and that all systems must have a balance, equilibrium or in biology terms, homeostasis. When the system is not at equilibrium, either a negative or a positive feedback occurs. Negative feedbacks discourages change and hence the change would be stable. Positive feedback encourages change and hence the change would be unstable.
Then Mr Heah started talking about the main gist of our lesson, which was on thermodyanic equilibrium.
Heat transfers in 3 ways: conduction, convection and radiation.
The range of visible light: Red Orange Yellow Green Blue Indigo Violet
Short wavelengths -------------------> long wavelengths
cool ---------------------------------------> hot
low energy ------------------------------> high energy
The sun emits long wavelengths and the Earth emites short wavelengths.
So, what does thermodynamic equilibrium mean?
It simply just means heat gained by the Earth, must be equal to the heat lost by the Earth.
However, due to an excess in greenhouse gases, we are losing less heat because greenhouse gases trap heat within the atmosphere.
Mr Heah then talked about CO2 which is a greenhouse gas. CO2 absorbs long wave radiation but allows short wave radiation which comes from the sun to pass through. So greenhouse gases actually act as a heat blanket for the Earth.
Global warming is due to the building up of more greenhouse gases which then traps more heat.
To see exactly how much heat is gained and lost and in what ways, Mr Heah got us to draw this diagram. It shows exactly how much heat is gained and lost and how if the Earth gains 100 units of heat.
That's all for now (:
-audrina
Monday, February 2, 2009
Geo lesson for 2nd.Feb! ^^
When today`s lesson just started, Mr.Heah tried to remember our names.~_~And then was the revision part. We reviewed some points including composition of atmosphere, function of Oxygen Carbon dioxide and Nitrogen.
Following we talked about systems equilibrium and regulatory forces witch include positive and negative feedback, positive feedback will cause encourages change while negative one will cause discourages change.
Next is the most important part we had for this lesson: Carbon Cycle! "What is the impact of man on carbon cycle?" Mr.Heah said it was very important to ASK QUESTIONS ABOUT THE QUESTION! So we need to consider about "What is/are the impacts?" and "What is carbon cycle?". And here are the mind map of carbon cycle.:)
Umm sorry maybe not clearly enough...
Ok that`s all for today.
Xue^_^lu