Intense meso-scale cyclones known as polar lows are frequently observed in the Arctic sector of the North Atlantic Ocean. During winter, cold-air outbreaks may be triggered by the large scale atmospheric flow exposing dry and very cold air to the relatively warm ocean surface. One of the ocean areas mostly favored for polar low development is between the Norwegian mainland and the Svalbard island. Due to the presence of the North Atlantic Current (NAC) the waters in this area may be warmer than 6o C in January. The large air-sea temperature differences experienced during cold-air outbreaks result in the formations of atmospheric fronts, large heat fluxes and sometimes the development of polar lows. The main scientific questions addressed by the STARS project are:

• Can satellite IR observations in combination with altimeter be used to detect possible sea-surface warming caused by strong winds under polar low events?
• Can we identify a Polar Low Indicator based on satellite data that could be a useful tool for polar low forecasting?
• Can the forecasting of polar lows be improved by introducing coupled atmosphere ocean models?
• Does the strong turbulent mixing induced by polar lows have an anomalously strong impact on the cooling of the North Atlantic Current?

The project has prepared an extensive database of EO data for polar low cases in the Norwegian Sea. These data have been used to derive a climatological study of polar lows in the Nordic Seas (Noer et al, 2011). A polar low indicator has been developed and tested at the Norwegian meteorological office polar low forecasting centre. The project is also investigating the application of SAR data to better understand surface wind fields in and around polar lows. Ocean models has been used to evaluate how the ocean adjusts and re-stratifies after PL events. An international workshop for Polar Lows was held in Oslo brought the polar low community together to discuss the results of field studies, new theoretical investigations and develop the polar-low community awareness of new EO data sets.