Weather School: A climate discussion.

It's easy to think that the global warming isn't happening when it gets colder where you live, but we need to remember it's global so even if it gets colder at your place the global temperature can still increase.

Global warming can be divided in two categories; man made and naturally global warming. Many global warming skeptics are using the fact that the sun has different kind of cycles and that for example they say its due to solar spots. Of course solar variability are affecting the climate, but the changes of the temperature can't be fully correlated with the warming. We also has volcano eruptions, but none of the latest volcano did affect the global temperature.

Some of the skeptics even doesn't fully understand the greenhouse effect, and mostly of the scientist that doesn't believe in that the anthropogenic emissions is the cause of the global warming is in a minority. This article (http://www.pnas.org/content/early/2010/06/22/1003187107.abstract) found out that most of the scientist that isn't a 'believer' doesn't actively publishing in this field. I think that's interesting, wonder why? I won't answer that and instead let my readers think about that.

In spirit of the climate discussion I will try to explain the greenhouse effect in several simple ways. I start with the easy and probably the most used way:

We can compare the greenhouse gases with a coat, it works the same way holding the heat inside, making the temperature increasing. This might easily explain the effect, but it can be harder to explain why increased anthropogenic gases would make the temperature increase. The easiest way is to think about it like you another coat on earth. More greenhouse gases means more 'coats'. Pretty simple and explains the essence of the greenhouse effect.

But my favourite explanation is one I learned from one of my teachers. It is still very easy to understand but you can explain a lot more than with the 'coat' explanation. We start with imagining a pub and a little cabin, between the cabin and the pub is a thick forest. If we imagine the forest as the greenhouse gases and the cabin as the open space. The heat or infra-red radiation can then be a drunk person leaving the pub, heading for the cabin. What happens when he walks through the forest? He will have trouble walking in a straight line and 'bounce' between the trees, if the forest is thicker he will have a lot harder to walk through the forest. This is how the greenhouse effect works, with more gases the heat will stay inside the atmosphere longer and heating up it more.

A more scientific explanation talks about 'windows' of radiation that depends on the structure of a molecule. A greenhouse gases has a specific structure that makes it absorb long-wave radiation (heat).

I hope you think this was an interesting reading, please comment and tell me what you thought about it or if you have a question.

//Osced

Kelvin Waves

Hi

I'm back again, as you are seeing I'm not really a blogger. But today I decided to write in my blog about a phenomena I'm working with: Kelvin Waves. You have probably not heard about them before, but they are important in the oceans. The Tide is actually linked through Kelvin waves.

To describe these waves, I will use the tide as en example. When tides is getting high, it will disturb the sea-surface, that itself creates this Kelvin Waves. These waves will travel along the coast at the right side in the Northern hemisphere and at the left side in the Southern hemisphere. These waves will also travel along the coast and creates a perturbation we could also call a tide. Because of that ocean basins are big, we rarely are seeing this Kelvin Wave propagating a whole revolution before the tide is turning, if that happened you will getting the both stages of the tide . But you can actually see that at some island that has the right length to do so.

Hope you liked it and please comment about what you are thinking about it.

//Osced

Weather School Part 3 : Twister or Tornadoes

Hi

I'm here to update my blog, I haven't updated it for a while because of that I haven't found something interesting to talk about. So today I will continues my Weather School with something that many thinks is interesting, Twister or more commonly named Tornadoes.

A tornado is a rapidly rotating column of air, which is contact with the ground. This rotationg column needs to have a suiffcient rotating before its called a tornado. If you have a tornado you should have a convective (strong upward winds) storm in the vincinity, either it's hanging from or positioned beneath the base of the cloud. It's the atmospheric pressure who defines how the tornado looks like and the damaging wind is extended outsided the outline of the 'tornado cloud'. Even if we doesn't got any cloud, we still can have a strong wind.

How a tornado really does work is hard to know, but they are still pretty amazing and beutifull. Something interesting is that the updraft in a tornado is many times stronger then the graviation accelration which implis tha we got strong pressure difference vertically.

Like usally please comment and give me your thought about this entry.

//Osced

Weather School Part 2 : Weather System Part One

In the latest part, I tried to explain how High and Low pressure system works. In this part I will continues on the same path and go deeper into them. A High Pressure system has often nothing interesting to point out, instead we will focus on storms aka a low pressure system. The only interesting with a high pressure system is that is usually cloudless.

Low pressure system can deepen or developed as it continues its path, the mean path is towards the east ( UK to Sweden to Russia) in the northern hemisphere. When the system deepens the winds grow stronger and the clouds gets bigger. In the centre of the system the winds goes upward and clouds forms. Why does the wind go up-wards ? The answer to that question is not easy to explain in layman terms, but I will try: The storm system need to have a mass-balance. When new air moves into the centre, the system needs to send away some to preserve the mass-balance.

A tropical cyclone is also a low pressure system, but is still a little different and I will describe them in the next Weather School
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If you wants to know more about low-pressure system, you only need to ask in a comment.

Hope you like it.

//Osced

Weather School Part One: Pressure

Welcome to my first part of my own little weather school, I will start with something easy like pressure.
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Pressure is measure of how much force a object has against a surface. The earth atmosphere has a standard pressure who is 1012 hPa. When a meteorologist are talking about high pressure or High they are talking about a region with a higher pressure then in the rest of the vicinity.

The fact of that high pressure often are connected with a beautiful weather is because of the vertical wind (downward) who create a region who has less clouds then a region with a standard pressure.

A low pressure is often connected with cloudy and rainy weather, this is also because of the vertical wind (upward) who here is contributing to the genesis of clouds.

If you has some question or want to correct something or if you like this particular entry please comment.

//Osced