Investigating changes in the climate- and ecosystemof Arctic sea iceusing remotely operated vehicles

The Arctic Ocean is currently undergoing a dramatic change. Decreasing sea-ice extent, thickness and age are changing important processes in the climate system. An increasing coverage of the sea ice by melt ponds and an increased amount of light transmitted to the upper ocean are also affecting the ice associated ecosystem. To document these changes, we operated different remotely operated vehicles (ROV) underneath the drifting sea ice of the Central Arctic Ocean. The newest underwater technology combined with a highly interdisciplinary sensor suite was successfully used for scientific investigations directly under the sea ice. The unique dataset of novel observations provided insights into the partitioning of solar shortwave radiation in and under sea ice, the deformation and topography of the ice cover, the distribution of sea-ice algae and ice algal aggregates and the ice associated primary production. The large range covered by the ROV surveys enabled us to quantify the spatial variability of physical as well as habitat properties. Despite the harsh climatic conditions and logistical difficulties in the high Arctic, the latest ROV technology proved to be a valuable tool for interdisciplinary sea-ice research.