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
posted by 08ip01 at
11:34 PM
4 Comments:
To answer your question on why desserts have a higher temperature than equatorial regions:
Firstly, the earth is tilted at an angle (23.5 degrees i believe), thus the equator is not always in fact the place where radiation from the sun is most concentrated. Rather, depending on the position of the earth in its rotation about the sun, the area of most concentrated radiation is sometimes 23.5 degrees north of the equator (the tropic of cancer) and 23.5 degrees south (the tropic of capricorn), when the earth is at a point called aphelion (point when Earth is furthest from the sun, occurring around june to july) and at perihelion (point when earth is nearest to the sun, occurring around december to january) respectively. Thus, during these times of the year, the most concentrated radiation hits the tropic of cancer and the tropic of capricorn, which is where you will observe a large number of desserts.
(ok, this doesn't really answer your question, but it's inclusion feels more complete).
Of course it is true that at majority of the time, the Equator does on the whole receive more concentrated radiation. Now, we also need to take into account Global Air Circulation. This is responsible for distributing heat around the Earth. if you would refer to Zhao Pei's explanation of global air circulation, you should realize the air currents rise at the equator, carrying with it heat. Thus, although the equator does receive more concentrated radiation, the heat is dissipated by the winds.
Hope this answers your question. :)
No, personally I believe that the reason why deserts' temperature is so high because it is very dry there. As you know, water has a high specific heat capacity, therefore for the same amount of heat supplied, wet places will be cooler than the dry ones. Plants also absorb sunlight for their photosynthesis hence in places that no plants are present like deserts, less sunlight is absorbed and converted into other kind of energy but heat. And there is also a difference in temperature taken in shade and outside the shade as well. And as you know, in deserts there can hardly be as much shaded area as in other places like jungle or forest so the temperature taken can be higher.
Haha, hopefully I've answered your question :D.
Is the temperature of a desert always high? At night, temperatures may drop to extreme lows. Is there an explanation for it?
Perhaps it has to do with the level of water vapour there. As we see from the tri-cellular model, the wind that reaches deserts are very dry because precipitation has already occured where the air rises (e.g. at the equator), which is another important factor for the formation of deserts. As it is so, maybe the amount of greenhouse gases in the air (and as scientists have discovered, water vapour is the most pre-dominant) will be dramatically lowered at deserts. This means that radiation that hits the ground is easily re-emitted at night because there is less of a 'blanket' surrounding it to absorb the heat.
I thought that the temperature of deserts was low at night because of the lack of clouds, thus the heat will escape faster when the sun goes down, something like a greenhouse effect maybe?
Post a Comment
Subscribe to Post Comments [Atom]
<< Home