Students from the University of Alabama in Huntsville successfully deployed three micro super-pressure balloon satellites in winter 2021. Students planned and implemented all phases of the project from obtaining funding, determining project timelines, preparing equipment, launching balloons, designing and implementing a website, writing daily blogs on the balloon progress, and analyzing the data. The objective of the flights was to use the balloons as a meteorological tools to study conditions in the lower stratosphere (12 - 14 km), as a tracer for evaluating modeled air parcel trajectories, and as an outreach and educational tool. The tee balloons successfully traveled hundreds of thousands of kilometers, making an accumulated total of 16 global circumnavigations. Toughout the project, students made connections with hundreds of researchers, ham radio operators, STEM groups, and other students around the globe. The balloons provided velocity telemetry within many different weather regimes, including vigorous jets over the Himalayas, slow-moving equatorial air masses over the middle of the Pacific Ocean, and dense polar air masses over the Arctic Circle. This study has found that the accuracy of HYSPLIT calculated trajectories using Numerical Weather Predication (NWP) meteorological data can be quantified using parcel velocity, duration of trajectory forecast, and spatial resolution of the NWP model.

During the 2022/2023 Antarctic summer, eight pico balloon flights were depolyed from Neumayer Station III (70.6666° S, 8.2667° W), yielding valuable insights into the Antarctic stratospheric wind structure. Pico balloons maintain a lower altitude compared to larger super pressure balloons, floating between 9 to 15 km AMSL. The most impressive flight lasted an astounding 98 days, completing eight circumnavigations of the Southern Hemisphere. Throughout the flights, pico balloons encountered diverse air masses, displaying zonal velocities ranging from −50 to 250 km hr−1 and meridional velocities between ±100 km hr−1 . Total wind speeds observed were extensive, spanning from 2.0 to 270 km hr−1 . An significant finding revealed that lower-flying pico balloons could rise due to convection underneath the flight paths, influenced by high convective available potential energy environments, resulting in changes to the balloons’ float density. Moreover, the flights demonstrated that pico balloons tended to drift further south compared to larger stratospheric balloons, with some balloons reaching up to 8 degrees south of the equator and 2 degrees from the south pole. This article explores the pressure-testing process and deployment techniques for pico balloons, showcasing their transformation from inexpensive party balloons (costing less than 20 dollars) into efficient super pressure balloons. The logistical demands for pico balloon flights were minimal, with a single person transporting all materials for the balloons (excluding lifting gas) to the Antarctic continent in carry-on luggage. The authors aim to promote the application of pico balloons to a wider scientific community by demonstrating their usefulness.

We deployed six pico balloons with 20 m transmitters (14.09 MHz) from Neumayer Station III in the 2022 Antarctic summer. Our objective was to evaluate ionospheric propagation in lower latitudes. Leveraging the Weak Signal Propagation Reporter (WSPR) protocol, we transmitted and received telemetry data on a global scale. Each balloon remained airborne for over a month, with one completing eight circumnavigations of the southern hemisphere, transmitting WSPR beacon data for 98 days. Our analysis focused on signal propagation characteristics in the polar ionosphere and surrounding regions, considering factors such as location relative to the WSPR network and solar elevation angles. Alignment between solar elevation angles at transmitting and receiving stations indicated a relationship with signal reception; lower solar elevation angles proved crucial for long-range propagation. We discovered that, beyond a solar angle of 60 degrees above the horizon, no decodes were recorded beyond 7500 km. Most signal spots were observed within a 1000–5000 km range and solar elevation angles ranging from 1 to 80 degrees. Over Antarctica, spot occurrences peaked around 4 UTC, particularly during the early hours of the day. Our findings demonstrate the usefulness of pico balloons for propagation studies, providing insights into the WSPR network’s coverage over Antarctica and surrounding lower latitudes.