Sunday, 7 October 2012

Meteorology and Weather Prediction


Have you woken up one morning looked out your window and seen clouds? Then of course you open up a weather net work online and check to see if its suppose to rain later. The radar says nothing and yet the Satellite shows clouds. What?!?!? Confusing right? Why does it happen? Does this mean Radar is wrong?
No here's how it goes down, the Radar isn't looking at anything it cannot "see" but it sends radio signals, (It's kinda like how Bats fly and don't run into anything because they hear the echo they create.) In return if there is any precipitation in the area, the Radar will show you where the precipitation is. But the Satellite is Imagery, you will see clouds cover and cloud types, but you can't see what is going on  below the clouds.
So neither is right or wrong, they just both use different methods to getting the job done. And that doesn't mean their always correct or agreeing with each other.

So let's get more detailed about Radar's...
Radio Detection and Ranging, is the longer way of saying Radar. The weather surveillance radar systems normally use a parabolic antenna. (It's like a dish you have for T.V. or Internet.) It focus's a pulsed radio-frequency beam out into the Atmosphere, kinda light a search light. It does a 360 degrees scan of the radar site, it has a narrow beam and it points at different elevation angles, whenever it comes by.
The emitted energy that the radar antenna strikes its particles of precipitation. (Like Rain, Snowflakes, Freezing Rain, etc.) A portion of the engery is reflected back to the Radar, and the intensity of this energy is related to the number, size and type of precipitation particles.
It's hard to make out this picture but Basicly it's showing how the Radar works,
I'll focus on only a few of what's here. Notice the scale on the side? Yeah the colourful one.
That's the Intensity Scale, you can probably guess the "low" and "High" but just to clear it up, the light blue is the lowest, while the deep purple is the highest. The middle of the picture, is the Radar and the circles coming from the Radar are about 40km apart from each other. The farthest one is 250km.

Satellite... So I won't go so deep in detail with this, but basicly it's seeing the view from up high!
It mostly shows of the clouds and their forms. A lot of people go straight for the Satellite pictures to see whats up, they seem to understand the pictures, an actual imagine of whats happening. It's more effective, for us humans, to actual see whats going on. So when you see a picture from a Satellite you suddenly are like.. "Oh so thats what's happening?" because you see it for your self.
Here's a picture from a Satellite from the Environment Canada's, When you look at this picture you seem to understand what the weather is like right?? Being able to see makes a world of differance.

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