Land & Earth Observation

More than half of all Global Climate Observation System (GCOS) Essential Climate Variables (ECVs) (atmosphere, ocean and land) can only be measured via remote sensing from space and another quarter require at least some space-based observations. This section includes metrology support for all remote sensing techniques from all platforms including satellites, aircrafts, drones and surface-based remote sensing, along with observations that provide in situ validation of remote sensing techniques.

This section also covers the metrological needs of land-based in-situ observations. Land and its biosphere provide a natural sink for more than half of all anthropogenic CO2 emissions. Therefore, its continued health and sustainability is critical for achieving the net zero carbon goals needed to stabilise our planet. On the other hand, land can also be a source of greenhouse gas emissions, with potential tipping points such as methane release from permafrost in the cryosphere.

In this theme, our activities include developing standards and methods for the pre-flight and in-flight calibration and validation of sensors using remote sensing methods across the electromagnetic spectrum, remotely or locally deployed. It also covers the metrology needed to assign quality metrics to derived information products, i.e. accounting for retrieval algorithms, sampling and timescales that might span decades (historical and future). We also look to support those making or interpreting measurements of all land-based parameters - whether it be through laboratory calibrations or supporting field measurements in campaigns and networks.

Improving climate modelling accuracy

Identifying climate trends frequently relies on comparing data for sensitive indicators used in predictive models that can contain variability generated by affects such as measurement altitude. Ground-based, air-borne and satellite made observations need independent scrutiny to increase confidence in data consolidation. The introduction of more rig...
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Seeing ocean colour from space

Oceans are the largest active carbon sinks on Earth, absorbing more than a quarter of anthropogenic carbon emissions. Phytoplankton in the ocean, such as microscopic plants and algae, have a major impact on the ocean’s ability to absorb carbon dioxide. Satellite measurements of the sunlight reflected by the ocean – ‘ocean colour’ – can be used as a...
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Confidence in climate data

Central to our understanding of climate change are reliable Earth models. These models depend on complex measurements for validation of variables such as ice cover, cloud cover, sea level and temperature that can only be made from space using satellites. The Earth observation community needs to be able to compare and combine these satellite data, r...
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Improving atmospheric data

Greenhouse gases are accumulating in the Earth’s atmosphere and have created a heat-trapping layer which is driving climate change. Satellite instruments are used high in the atmosphere to generate gas concentration data but require on-going performance validation post launch. A more direct link of satellite measurements to the SI throughout their ...
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Ensuring accuracy in the upper atmosphere

Variations in ozone and aerosols in the Earth’s atmosphere affect air quality, weather and climate. One critical example of this is climate change, where the build-up of greenhouse gases is driving the warming of the planet’s surface. To assess the impact of tiny variations in atmospheric composition on long-term climate change, the Earth observati...
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