An unfortunate incident in the early stages of the Arctic Lower Troposphere Observed Structure (ALTOS) field campaign at Oliktok Point on the North Slope of Alaska has resulted in the campaign being terminated. The primary in situ measurement platform for the campaign was a tethered balloon for making ascents through the clouds with instruments that measure cloud microphysical properties, while ground-based instruments simultaneously collect additional data. During one of the balloon’s initial flights, its primary and secondary tethers broke. A radio-controlled cut-down device was activated to bring down the balloon, which landed with its instrument payload in the ocean. Because of the weather and estimated landing location, the payload could not be safely recovered. There were no injuries or damage to other equipment but, for now at least, the ALTOS crew will be going home. If replacement instruments can be obtained in the next few months, there is a possibility the campaign could restart in the spring. The remaining equipment will be stored in Oliktok while this possibility is explored by the science team.
