The European Space Agency's (ESA) Arctic Weather Satellite (AWS), launched in August 2024, has been successfully integrated into the European Centre for Medium-Range Weather Forecasts (ECMWF) operational system as of July 10, 2025. This integration represents a significant advancement in weather forecasting, particularly for the challenging Arctic region.
The compact AWS satellite is equipped with a sophisticated 19-channel microwave radiometer, featuring a groundbreaking 325 GHz sounding channel. This advanced channel enhances sensitivity to ice clouds, a critical factor for improving forecast accuracy. The satellite's ability to measure atmospheric temperature and humidity profiles through cloud cover, even in difficult conditions, provides invaluable data. ECMWF's assimilation of AWS data has already led to demonstrably improved forecasts, especially in high-latitude areas. The incorporation of sub-millimeter channels has increased the model's responsiveness to ice clouds, resulting in more precise short-range predictions for temperature, humidity, and wind.
The success of the AWS underscores the transformative potential of small-satellite constellations in revolutionizing weather forecasting. It serves as a vital precursor to ESA's proposed EUMETSAT Polar System – Sterna (EPS-Sterna) constellation, which plans to deploy six similar satellites in polar orbit. This "New Space" approach, characterized by rapid development and cost-effective deployment, has proven its efficacy through the AWS's performance and its positive influence on operational weather forecasting.
This advancement is particularly noteworthy as the Arctic region is experiencing climate change at an accelerated pace, making precise weather monitoring crucial. The AWS data, alongside the anticipated EPS-Sterna constellation, is poised to bolster climate research by offering essential insights into Arctic conditions. The mission's ability to provide high-quality, passive microwave measurements from a small, economical satellite demonstrates a new paradigm in Earth observation. The AWS's impact on forecast accuracy is comparable to that of instruments on much larger, traditional missions, highlighting its significant contribution. Furthermore, the satellite's advanced features offer clearer visibility of phenomena like typhoons by detecting colder brightness temperatures, marking a substantial leap in meteorological data assimilation.