Leicester scientists contribute to latest climate satellite mission EarthCARE

A SpaceX Falcon 9 rocket is due to launch tonight at 11.20 pm BST (15.20 PDT in California), carrying a major Earth Explorer satellite, EarthCARE (Earth Clouds, Aerosol and Radiation Explorer), a joint mission between ESA (the European Space Agency) and JAXA (the Japan Aerospace Exploration Agency). The UK is a major partner in ESA supporting 15 years of world-leading research through NCEO (the National Centre for Earth Observation) at the Universities of Leicester, Reading, Oxford, and Imperial College.

EarthCARE will revolutionise our understanding of how clouds and aerosol particles affect weather and climate, helping to resolve disagreements between projections of future climate. Atmospheric aerosols are suspended particles, such as smoke and dust, that are the seeds from which clouds grow. When traffic or industry release aerosols, they can alter the brightness of clouds and likelihood that they rain. EarthCARE’s instruments are designed to unpick the mechanisms that cause these changes.

EarthCARE will also be tested for its ability to improve our weather forecasts which, if successful, will lead to future EarthCARE instrumentation flying as part of the operational instruments underpinning forecasts. This is significant for people in the UK because sectors such as transport and agriculture depend on knowledge of, for example, intense winter storms which bring flooding.

First proposed in 1993, this €800 million satellite is the most complex Earth Explorer mission to date. 23 UK organisations have been involved in the design and development of the satellite over the last 30 years. The satellite brings together four types of measurements on a single platform for the first time. The instruments are; The Cloud Profiling Radar (CPR), built  in Japan, reflects radio waves off droplets within clouds to determine their location and fall speed. The Atmospheric Lidar (ATLID) does similarly for aerosols using an ultraviolet laser. Two important instruments have been built by companies in the UK. The Multi-Spectral Imager (MSI) photographs the area around the radar beam while the Broad-Band Radiometer (BBR) measures the total energy leaving the Earth. The combination of the four instruments will monitor each step in sunlight moving through the air, determining the balance of energy between the surface and atmosphere.

Working with colleagues across the world, University of Leicester NCEO staff have developed a more realistic way of calculating the in-cloud signals seen by the radar and devised new mathematical algorithms which provide vertical profiles of the profile fall speed. For the first time, scientists will be able to observe from space the speed at which particles fall through cloud decks and precipitate to the surface. This is fundamental to whether we experience rain or hail or snow and its intensity.

More recently, Dr Kamil Mroz at the University of Leicester has developed a world-leading method to add knowledge of the total water in the cloud particles and their characteristic size to the fall speed. Understanding this process is crucial for comprehending the lifecycle of clouds, including how rain forms, intensifies, and dissipates during storms.

Professor John Remedios, Director of NCEO and a University of Leicester atmospheric science expert commented:

“The launch of Earthcare, with its sophisticated scientific payload, is a major milestone after many years proving the technology. We are very excited by the possibility to actually look inside clouds and observe the droplet motion and growth whether they fall downwards directly or rise in the updrafts which fuel the intensity of storms. Modelling these processes will give us new insights into the ways in which storms grow, their influence and response to climate change and how we can harness this knowledge to improve weather predictability.

“In the UK, we see that rainfall plays a fundamental role in our working lives, our homes, and our leisure. This mission enables our world-leading scientists to make a difference at home and across the world. We will work closely with weather forecast agencies such as the Met Office and European Centre for Medium Range Weather Forecasting (at Reading) to do this.”