ESA selects WIVERN as 11th Earth Explorer mission

The journey began in 2020, when ESA launched a Call for Ideas for bold new missions that could push the boundaries of Earth science and satellite technology. From 15 proposals, four were subsequently shortlisted for detailed study. In 2023, that shortlist was narrowed further to two contenders: WIVERN and CAIRT.

Following the release of a detailed report for each mission (linked below) and during an in-depth User Consultation Meeting in July, both mission concepts were scrutinised by the scientific community and ESA’s Advisory Committee for Earth Observation (ACEO). Based on their evaluation, ACEO recommended that WIVERN be selected for implementation as Earth Explorer 11.

Today, ESA’s Earth Observation Programme Board confirmed that decision – formally selecting WIVERN as the next Earth Explorer.

WIVERN, which is short for wind velocity radar nephoscope, will provide the first measurements of wind within clouds together with information on the internal structure of clouds, filling a significant gap in the global satellite observing system. It will also deliver profiles of cloud water droplets, rain, snow and ice water.

Carrying a dual-polarisation, conically scanning, 94 GHz Doppler radar with an 800 km swath, the mission promises to improve forecasts of hazardous weather and provide new insights into severe storms. It will also contribute to the climate record of cloud and precipitation profiling.

ESA’s Director of Earth Observation Programmes, Simonetta Cheli, said, “After a rigorous selection process, we are excited to welcome WIVERN to the Earth Explorer family and we are eager to see the groundbreaking science it will deliver.

“Earth Explorer missions have consistently surpassed expectations, using breakthrough technology to deliver vital insights into our planet – from climate dynamics to ice melt and gravity.

“Both the WIVERN and CAIRT concepts embody scientific excellence, and I want to thank all the teams who worked tirelessly to develop them. Their outstanding efforts made ACEO’s recommendation process a particularly challenging one.”

CAIRT – short for changing-atmosphere infrared tomography – would have provided the measurements needed to make a necessary step change in understanding the links between climate change, atmospheric chemistry and dynamics in the altitude range of about 5 to 115 km.

“Ultimately, WIVERN offered the broadest range of scientific and societal applications – spanning atmosphere, ocean, and ice – while its exceptionally wide swath promised near-daily coverage of vast areas of Earth’s surface,” noted Rune Floberghagen, Head of ESA’s Climate Action, Sustainability and Science Department.

Professor René Forsberg, Chair of ACEO, added, “It was indeed a very difficult decision. CAIRT’s scientific goals are both timely and important, addressing major unknowns with important societal benefits as well. While we recommended WIVERN as Earth Explorer 11, we also strongly encourage continued scientific studies and field campaigns for CAIRT to keep the door open for possible future implementation.”