Radiosonde launch

Measuring climate change

Vaisala

While climate change is a well-accepted phenomenon, its study has challenged scientists for many decades. Encompassing temperature, humidity, atmospheric pressure, winds, rainfall, atmospheric particle count and numerous other meteorological elements in a particular region, scientists depend on different instruments for measurement in addition to a vast number of empirical indicators to quantify the changes observed.

Each year has meant these tools produce ever more sophisticated readings; however the search for a high-precision upper-atmosphere instrument to improve long-term research on climate change remains. The international scientific community is now collaborating on developing a meteorological instrument that will provide superior quality and highly reliable data to shed light on the dynamics of climate change.

Research evolution

The study of climate change started as a long-term, comparative study of changes occurring in the earth’s natural resources. Today it has evolved into a much more scientific process of deploying tools such as radiosondes, which are meteorological devices, launched from the ground to measure temperature, humidity, pressure, wind speed and direction in the upper atmosphere. Other measurement tools are surface weather stations and satellites – together with sophisticated computer models – to evaluate and project the changes in atmospheric temperature and composition.

To ensure national and international needs for climatological information were addressed as efficiently as possible, a globally coordinated monitoring system for the climate, the Global Climate Observing System (GCOS) was set up in 1992. Information obtained through the GCOS network is currently used for climatological observations by countries across the world, and also as an input for climatological models that help estimate how the climate will change in the future.

In keeping with GCOS’ mission, i.e. to produce the highest quality long-term climatological data as well as calibrate data from other global systems such as satellites and existing radiosonde networks, the GCOS Reference Upper Air Network (GRUAN) was set up.

Reference radiosonde will shed light to the dynamics of climate change

Radiosonde relevance

While the current radiosonde networks support normal weather observation needs rather well, they do not provide accurate enough information for climate change observations. The biggest problem of existing radiosondes relates to imprecise upper-air measurements of humidity levels.

Humidity is the most abundant and subsequently the most important greenhouse gas in the earth’s atmosphere. Understanding the changes in its concentration are imperative to better understanding global warming. However, it is also one of the most difficult parameters to measure with high precision and accuracy, especially in the upper troposphere and stratosphere where conditions are extremely cold and dry.

Supported by the World Meteorological Organization (WMO) and the United Nations Educational, Scientific and Cultural Organization (UNESCO), the GRUAN project started to take shape to deliver to scientists a high-precision instrument that would provide superior-quality climatological data on the upper parts of the atmosphere.

Vaisala, the leader in meteorological monitoring systems and backed by 70 years of history, came forward to take on this important development challenge. Scientific evaluation started early this year in January, with the intention that after piloting the instrument will be further developed according to the experiences gained from the international scientific community

Deployment of the ‘new age’ radiosonde

The first generation operational reference radiosonde is expected in Q4 2009 and the initial parameter that it will help measure is humidity. Specifically, the Vaisala reference radiosonde will provide high-quality measurements high up at over 30km above the earth’s surface.

What’s more, scientists will be able to provide initial feedback to Vaisala on its performance. In parallel, Vaisala will continue development of the radiosonde to provide even more precise measurements. The feedback will help enhance the radiosonde’s functionality until such a time that the final product will be useful for the climate scientists.

A global community project, the benefits of this development will be shared equally with all countries. Vaisala has kept aside commercial gain and is driving the project forward as a key Corporate Social Responsibility programme.

The overall goal of GRUAN is to establish 30-40 stations which will use the operational reference radiosonde in addition to other instrumentation, representing different climatological conditions around the world.

Demanding long-term commitment, resources and cooperation with the scientific community, the program will not change things overnight. But the journey has definitely begun; we are on the threshold of ground-breaking research, the kind that will make us keenly aware of climate change dynamics, the kind that will hopefully help put a halt to the events that lead to them.

Vaisala
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