A distributed atmosphere - sea ice - ocean observatory in the central Arctic

To understand the current evolution of the ArcticOcean towards a less extensive, thinner and younger sea ice cover is one of the biggest challenges in climate research. Especially the lack of simultaneous in-situ observations of sea ice, ocean and atmospheric properties leads to significant knowledge gaps in their complex interactions, and how the associated processes impact the polar marine ecosystem. Here we present a concept for the implementation of a long-term strategy to monitor the most essential climate- and ecosystem parameters in the central ArcticOcean, year round and synchronously. The basis of this strategy is the development and enhancement of a number of innovative autonomous observational platforms, such as rugged weather stations, ice mass balance buoys, ice-tethered bio-optical buoysand upper ocean profilers. The deployment of those complementing platforms in a distributed network enables the simultaneous collection of physical and biogeochemical in-situ data on basin scales and year round, including the largely undersampledwinter periods. A key advantage over other observatorysystems is that the data is sent via satellite in near-real time, contributing to numerical weather predictionsthrough the Global Telecommunication Network(GTS) and to the International Arctic BuoyProgramme (IABP). The first instruments were installed on ice floes in the Eurasian Basin in spring 2015 and 2016, yielding exceptional records of essential climate- and ecosystem-relevant parameters in one of the most inaccessible regions of this planet. Over the next 4 years, and including the observational periods of the Year of Polar Prediction (YOPP, 2017-2019) and the Multidisciplinary drifting Observatoryfor the Study of the Arctic Climate(MOSAiC, 2020), the distributed observatorywill be maintained by deployment of additional instruments in the central Arcticeach year, benefitting from international logistical efforts.