How third-generation weather satellites make weather forecasts more accurate

AND WHY WE ARE ON THE VERGE OF A WEATHER APP WITH A PERSONALIZED FORECAST

OHB Redaktionsteam
Published on
by OHB Redaktionsteam, OHB SE

An individualized weather forecast which is never wrong no matter where you are and accurate for many days in advance may currently just be a pipe dream. However, it will be possible with the Meteosat Third Generation (MTG) weather satellites. OHB is supplying the platform and a number of the measurement instruments for the total of six satellites. Dr. Christoph Bartscher is the MTG Instruments Program Manager at OHB System. He has been overseeing the MTG project in Munich from the outset. So he knows why weather satellites are not only important for gardening but can even save lives.

 

Precise weather forecasts are crucial for hikers, farms and pilots

“Do I need to take an umbrella to work today?” An answer to this question can be gained by looking out the window, watching the conventional weather forecast on TV or going on to Facebook (“Good morning. It looks like rain today in Oberpfaffenhofen. Make sure you take your umbrella”). In our daily lives, weather forecasts like these are convenient more than anything else.

Yet, there are situations in which accurate weather forecasts are crucial – for hikers for example. For them, conditions can quickly become very treacherous. Given the nature of mountain ranges, dangerous swings in the weather may occur locally. If I am a hiker and know that a snow storm is already raging behind the mountain ridge, this can prompt me to descend to a valley or find a shelter. Consequently, this can be a matter of life or death.

Agriculture is equally as dependent on accurate weather forecasts, e.g. warnings of frosty conditions, hailstorms or heavy rain, which in some cases may occur as very local phenomena. Another important example is aviation. If the pilot knows the location of a thunderstorm or gale, he can fly around it or at least give his passengers early warning. He can also make better use of tail winds with this knowledge to save fuel and power the environmental impact.

“At certain altitudes, gales and thunderstorms are so intense that they pose a threat to life and limb. This particularly applies to small aircraft. If I fly into a storm in a two-motor Cessna, it can easily rip the wings off.”

How do weather forecasts arise?

A lot of data used by meteorologists comes from weather balloons, automatic weather stations, buoys and weather satellites. In Europe, the Meteosat satellites are primarily used. They are operated by the European Organization for the Exploitation of Meteorological Satellites EUMETSAT, which forwards the weather data to the national authorities such as the German Weather Service. 30 European countries are members of EUMETSAT.

Seeing “invisible” air humidity to prevent disasters

The basic problem with many weather forecasts is that many phenomena are difficult to observe or can only be predicted at very short notice – frequently with dire consequences. To give an example, small islands in the Atlantic are repeatedly inundated by unexpected heavy rainfall. These bad weather fronts often literally come out of the blue – sometimes within half an hour. These extreme weather changes can cause flooding or landslides, thus posing a real threat to human life. The problem is that the photos taken by weather satellites only show humidity in the form of clouds. But there is also humidity in the air even if no clouds are visible. This means that humidity is always in motion outside clouds but we can’t see it. Imaging processes from space have previously not been good enough to solve this problem.

“For one thing, you cannot detect any differences in altitude and, for another, we need to render the speed, direction and height of the invisible humidity visible.”

For this purpose, the third-generation Meteosat satellites (MTG) will be fitted with an infrared sounder (IRS) for the first time. This instrument can detect such humidity and its movement in the earth’s atmosphere. This marks a major step forward. “The sounder will help us to increase the early warning period for many weather catastrophes to several hours and perhaps even a day. OHB System holds prime responsibility for this instrument for the MTG satellites. Meteorologists are eagerly awaiting its completion.

 

“The MTG instruments will achieve a resolution of one to two kilometers – sufficient to detect large villages.”

The new data will also improve the quality of the daily weather forecast. Currently, we can predict the weather for a maximum of five days with a reasonably high probability. MTG will be paving the way for a substantial improvement in quality.

“The goal is to achieve a solid ten-day forecast. In this way, we can double the length of the long-range weather forecast.”

MTG will also be able to help with research into phenomena related to global warming. To this end, the satellites will be fitted with instruments capable of detecting gases in the atmosphere contributing to global warming. Although this is not the main purpose of the mission, it is still an added benefit. The closes the circle as far as the weather is concerned as global warning will trigger more extreme weather phenomena, which we can see and understand more clearly thanks to MTG.

A prestige project for OHB System

More than 200 experts at OHB System have been working on the MTG instruments at times, posing a major organizational challenge. Other MTG instruments include search-and-rescue antennae and the lightning imager instrument.

“We are increasingly being perceived as a company with a high reputation in optical instruments. MTG marks a quantum leap for us. The team are performing outstanding work.”

MTG brochure: Next-generation weather satellites

 

Download the PDF here.

Based on navigation data gained from Galileo, the weather app of the future is being developed

Looking forward, the more precise MTG data will make daily use of mobile devices easier. Working in conjunction with MTG, the Galileo navigation system could assemble enough data for each mobile device to offer users their own personal weather service. They can then use it on their way to a neighboring town or to the shopping mall - always localized and always up to date. It would also be possible to link the weather app with the smartphone user’s personal calendar and to predict weather conditions for a given date, place or event.

“I can well imagine that in a few years from now I will be able to spontaneously ask my smartphone whether I can climb a given mountain today or whether it would be advisable to wait until tomorrow.”