Special Observing Period (SOP) Data for the Year of Polar Prediction site Model Intercomparison Project (YOPPsiteMIP)

Abstract. The rapid changes occurring in the polar regions require an improved understanding of the processes that are driving the changes. At the same time increased human activities, such as marine navigation, resource exploitation, aviation, commercial fishing, and tourism, require reliable and relevant information. One of the primary goals of the World Meteorological Organization’s Year of Polar Prediction (YOPP) Project is to improve the accuracy of numerical weather prediction (NWP) at high latitudes. During YOPP, two Canadian observatories were commissioned and equipped with new ground-based instruments for enhanced meteorological and system process observations that are considered to be “supersites” for addressing YOPP objectives, while other pre-existing supersites in Canada, the United States, Norway, Finland and Russia provided data from ongoing long-term observing programs. Data from these seven supersites were amalgamated and are being used to evaluate NWP systems from several international forecast centers and to perform meteorological process studies with the aim of improving NWP performance in the Polar Regions. In order to increase data useability and station interoperability, novel Merged Observatory Data Files (MODFs) have been created for these seven international supersites over two Special Observing Periods (February to March 2018 and July to September 2018). All observations collected at the seven supersites were compiled into this new standardized NetCDF MODF format, simplifying the process of conducting pan-Arctic NWP verification and process evaluation studies. This paper describes the seven Arctic YOPP supersites, data collection and processing methods, and the novel MODF format and output files, which together comprise the observational contribution to the associated model intercomparison effort, termed YOPP supersite Model Intercomparison Project (YOPPsiteMIP). All YOPPsiteMIP MODFs are publicly accessible via the YOPP Data Portal (Whitehorse: https://doi.org/10.21343/a33e-j150, Iqaluit: https://doi.org/10.21343/yrnf-ck57, Sodankylä: https://doi.org/10.21343/m16p-pq17, Utqiaġvik: https://doi.org/10.21343/a2dx-nq55, Tiksi: https://doi.org/10.21343/5bwn-w881, Ny-Ålesund: https://doi.org/10.21343/y89m-6393, Eureka: https://doi.org/10.21343/r85j-tc61), hosted by MET Norway, with corresponding output from NWP models.