WindBorne Global Sounding Balloons: Observations and Forecast Impacts

WindBorne Systems has developed a novel balloon-based observation system, enabling constellations of balloons to be flown throughout the troposphere for extended periods of time. Each balloon, known as a Global Sounding Balloon (GSB), can fly for weeks at a time while being remotely directed to ascend and descend from a few hundred meters above the earth surface to the lower stratosphere, collecting up to 50 vertical profiles of wind speed and direction, pressure, temperature, and humidity per flight. Data collected by GSBs is available in real-time and can be used as a data source for numerical weather prediction initialization and verification, validation of parameterizations, and climate reanalyses.

Over the past 5 years, over 1250 GSBs have been flown and have collected atmospheric data throughout much of the world. During the first 4 years of operations, the GSB was developed, demonstrated and refined during large-scale intermittent field campaigns. In early 2023 WindBorne began operating a persistent constellation of GSBs and by early 2024, the constellation averaged 15 GSBs aloft at any given time with an expected increase to 100 aloft, supporting collection of over 300 vertical profiles of data per day, by the end of 2024.

WindBorne has partnered with the United States National Oceanic and Atmospheric Administration to optimize the assimilation of GSB observations for use in numerical weather prediction, and to further assess the impact of the observations on forecasts. During summer and autumn of 2022, 169 GSBs were flown in the tropical Atlantic and the Arctic, collecting observations throughout large parts of the northern hemisphere during a 3 month period. The observations were assimilated into retrospective runs of the NOAA National Center for Environmental Prediction Global Forecast System (GFS) and reduced both average geopotential height errors in the tropics by 2-3% and tropical cyclone forecast track errors by up to 18%. Experiments are currently underway to assimilate GSB data into AI-driven weather prediction models.