Forecast an El Nino or La Nina!
|You can see if an El Nino or a La Nina is coming!|
|Who hasn't heard of El Nino and la Nina? Almost no one! But who can tell if one of these events that change our weather and climate is coming. Scientists are working to forecast El Nino and La Nina events but as yet our best way to tell what is coming is to look at satellite ocean data and watch for these features as they travel across the ocean. And you can do that!|
First let's think about what an El Nino or La Nina is and how it affects
us. The simple explantion is that they are hot and cold ocean events
that start in the tropical Pacific Ocean. These 'hot and cold' events cover
large areas of the tropics, move from weat to east, and can spread north
and south along the coasts of the Pacific ocean. The events are so large
that they affect the local weather and change the jet stream which affects
global weather. For more information read further!
|Let's take a look at the ocean!!|
This picture was made from data taken from a satellite that measures the height of the ocean. By measuring the height of the ocean surface we can make a map that gives us information about the amount of heat in the ocean. The 'bottom line' is that hot water expands and is higher and cold water takes up less space so it is lower. Think about designing an experiment to prove this? (Hint!)
Check out this image taken from our TOPEX/Poseidon satellite
- Why are there stripes on this image? Hint!
- What color is shows a 'normal' sea surface height and temperature? Hint!
- Where in the ocean are the high areas indicating warm water?
- What areas of the world (countries) are near high (warm) or low (cool) water?
Now for another view .....
- Let's look at a recent image that uses 10 days of data which gives a more global coverage.(Why's that? Hint!) Check out where TOPEX/Poseidon is now!
- In this image green shows areas that are a normal height, blue and purple are lower (cooler) than average and yellow, red and white are areas that are higher (warmer) than average.
- How much is 14 cm?
- Where are the high areas indicating warm water?
- What areas of the world are near high (warm) or low (cool) water?
|Let's compare and forecast!|
||The image to the left is taken at the height of the '97-'98 El Nino. Note the area of higher and warmer than average water (white) in the east.||
||The image to the left is the '98-'99 La Nina. Note the area of lower and cooler water in the tropical Pacific, this later moved to the east|
|How does the ocean make a difference in the weather?|
The ocean affects the temperature and the amount of moisture in the
air. How could you do an experiment to test this? Hint!
With more moisture in the air, it is more likely to rain if the air is cooled. How could you do an experiment to test this? Hint!
With less moisture in the air, even as the air cools going over mountains there will be little rain.
Check out these graphics and write your own captions!
|So why do we need to know what's coming next?|
The El Nino and La Nina conditions are not necessarily bad, its just that we and the landscape adapt to average or 'normal' conditions, so when the weather is not normal, it often causes problems.
Map showing some of the impacts from the 1997-98 El Nino
Drought is when there is not enough rainfall to support activities that
usually occur on a piece of land. These activites include growth
of natural vegetation, use of the land for grazing or support of a city.
In the case of the latter, the affects of the drought can often be lessened,
but in natural areas the affects often result in dramatic natural population
-What is your average rainfall?
- What would happen to the area that you live in if you had half your annual rainfall?
- If you knew that you would be getting half the average rainfall what could people do so it would matter less?
-When are fires 'good' and when are they 'bad'
Satellite view of Hurricane Mitch
(Courtesy:Same old Someone Else)
|What would be affected in your life if you were without power for a
How would a farmer be affected?
How would a city be affected?