Climate modelling is a complex activity, crucially important for making predictions for institutions such as the Intergovernmental Panel on Climate Change (IPCC), whose reports are used to define policies and seal the conventions needed to combat climate change at the global level.
Providing data for atmospheric species to the Climate Change Service
Understanding the full complexity of the climate system requires high-quality data sets for all aspects of the Earth system (atmosphere, oceans, cryosphere, etc.). BIRA-IASB contributes to this effort by providing data for different atmospheric species to the Climate Change Service of the Copernicus programme coordinated by the European Centre for Medium-range Weather Forecasts (ECMWF).
Copernicus in turn makes this climate data available to a wide range of users such as the scientific community, decision-makers, the private sector and interested citizens.
In order to provide all these stakeholders with reliable, easily accessible and well-documented data, these data are encoded according to standard formats allowing easy application, and providing all the information necessary for their use: geolocation and date, data relating to the instrument, measurement uncertainties, etc.
A detailed description of data processing methods is also provided so that any potential problems can be traced.
The challenge of precise and reliable aerosol data
Among the data provided by BIRA-IASB, time series are provided for stratospheric aerosols. These tiny airborne particles scatter light and play a key role in climate change where they partially offset the greenhouse effect.
Unlike molecular species, whose spectral response to well-defined structures can be accurately measured in the laboratory, aerosols, due to their particulate appearance, have a variable spectral response depending on their composition, the number and size of particles, and on some changing and uncertain parameters.
Their characterisation therefore remains a challenge and this is one reason why they have been identified as an "essential climate variable" by the IPCC. The role of researchers is to develop algorithms to find the spectral signatures of the main atmospheric components, including aerosols, in order to decode satellite measurements as accurately as possible to obtain increasingly precise and reliable aerosol data.
