1. ICT in Weather Forecasting
The Use Of
ICT in Weather Forecasting
Main Menu 1.
Introduction on the use of ICT in Weather forecasting 2.
The use of satellites
Sources and collections of data 3.
Other weather measurements 4. 5.
Processing the data

2. Introduction on the use of ICT in Weather forecasting
A daily weather forecast involves the work of thousands of
observers and meteorologists all over the world,
and the work of thousands of  machines
Modern computers make forecasts more accurate
than ever, and weather satellites orbiting the
earth take photographs of clouds from space.
Forecasters use the observations from
ground and space, along with formulas and
rules based on experience of what has
happened in the past, and then make their forecast.

3. Satellites
Weather satellites have been our eyes in the sky for over thirty years,
Today, satellite images showing the advance of weather fronts are regular elements of the evening news.
Infra-red cameras mounted on orbiting satellites also transmit valuable weather data back to earth. There are two types of satellites used which are :Geostationary satellites these monitor the movement of the clouds, and Polar orbiting satellites provide temperature data.
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All the data collected is sent to the forecasting model and processed.

4. Sources and collection
of data
A huge amount of data is collected everyday to assist in forecasting the weather. The data is collected from land-based stations, from out at sea, from the air and from orbiting satellites. This data is collected by using automated instruments with their own embedded microprocessors,
The data is then stored in memory before being passed on to larger computers for processing.
The important weather data collected includes:
The temperature
Wind direction
The Humidity
The wind speed
The air pressure

5. Other Weather Measurements1.
Weather Balloons- these are released daily from many locations around the world .Each balloon is fitted with a miniature radio transmitter. Weather data including temperature, humidity and pressure are broadcasted from the balloon.
Radar Stations-these feed large amounts of weather data through for processing. A special kind of radar, called Doppler radar, is used to track rain and clouds as they move through the atmosphere. It also used to track weather balloons as they rise through the air. 2. 3.
Weather data is also provided from instruments on aircraft and from ships. The ocean temperature and currents have a large effect on the worlds weather this data is also recorded and sent for processing.

6. Forecasting Model
In order to forecast weather, a computer program has been made to model the behaviour of the atmosphere.
The model involves making large numbers of very complicated calculations using the enormous quantity of data being input to the computer.
The power of the super computer is measured in flops (Floating point operations per second).
The MET office supercomputer, the Cray T3E, uses a massively Parallel Processor (MPP) system with 700 processor each working on calculations.
Floating point calculations means performing calculations on fractions and non-integer numbers which are quite complex operations for computers.

7. What is Parallel Processing?
The simultaneous use of more than one CPU to execute a program.
Ideally, parallel processing makes a program run faster because there are more engines (CPUs) running it.
In practice, it is often difficult to divide a program in such a way that separate CPUs can execute different portions without interfering with each other.

8. Processing the data
In a typical weather-forecasting system, recently collected data are fed into a
computer model in a process called assimilation.
This ensures that the computer model holds the current weather
conditions as accurately as possible before using it to predict how the weather may change over the next few days.
Weather forecasting involves processing a lot of data, but interpretation
can be difficult because of the chaotic nature of the factors that affect the
weather. These factors can follow generally recognized trends, but meteorologists
understand that many things can affect these trends. With the advent of computer models and satellite imagery, weather forecasting has improved greatly. Since lives and livelihoods depend on accurate weather forecasting, these improvements have helped not only the understanding of weather, but how it affects living and nonliving things on Earth.
The chaotic nature of the atmosphere imposes a limit on the predictability of the weather. The predictability limit is estimated to be about two weeks. Predictions beyond this limit are necessarily statistical rather than deterministic. Current operational weather prediction has not yet reached this predictability limit.

9. Weather Forecasting
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