Nobel Prize for physics winner shaped ground-breaking Earth-observing mission
Professor Hasselmann devised a system for measuring ocean waves from space.
Klaus Hasselmann, this year’s Nobel Laureate in Physics, was instrumental in shaping a groundbreaking Earth-observation expedition that laid the path for modern studies of our planet’s ecology.
The prize was given to the German oceanographer and climate modeller for his contribution to physical modelling of Earth’s climate, which has allowed scientists to quantify natural climate variability and better predict climate change. Last Thursday, Hasselman shared half of the 2021 Nobel Prize in Physics with scientists Syukuro Manabe and Giorgio Parisi for their work on disorder and fluctuation.
Hasselman, who is now 89 and works at Germany’s Max Planck Institute for Meteorology, was also a member of an expert panel that helped the European Space Agency (ESA) develop its Earth observation programme and build its first mission dedicated to studying Earth from space in the 1970s.
In a statement, ESA Director General Josef Aschbacher remarked, “We express our most sincere congratulations to Prof. Dr. Hasselmann for his well-deserved Nobel Prize.”
Hasselmann created a method for measuring ocean waves using synthetic aperture radar (SAR) images for this mission, according to an ESA release. SAR sensors send a signal to the ground and measure how much of it is reflected back to them. Environment-monitoring satellites are increasingly using these technologies today, and Hasselmann’s technique is still in use on current Earth-observing satellites like the European Copernicus Sentinel-1 radar mission.
“Without no doubt, we have best operational wave monitoring, or ‘wave mode,’ from Sentinel-1 today — a source of vital data for ocean forecasting, making maritime traffic safety,” Aschbacher said in a statement.
Launches this year!
This year also happened to be the 30th anniversary of the ERS-1 mission. ERS-1, which was launched on July 17, 1991, was Europe’s most complex spacecraft at the time, according to the space agency. The 5,256-lb. (2,384 kilogrammes) satellite also carried a radar altimeter (a sensor that sends a radar pulse to the ground and measures the distance based on the time it takes for the signal to return) and a wind scatterometer (which measures how a radar signal is affected by disturbances in Earth’s atmos) in addition to the imaging synthetic aperture radar that was used for wave monitoring. Before failing in March 2000, the project had collected data for nine years about Earth’s atmosphere, seas, ice cover, and land conditions, having outlasted its expected lifespan by eight years.
ERS-2, its successor was already present in orbit at the time, enabling ESA to flawlessly continue to gather information about the planet change. ESR-2, launched in 1995 also held a dedicated sensor for monitoring ozone layer.