[A-CG52] Science in the Arctic Region

[ACG52-15] The JAMSTEC Arctic regional Reanalysis system (JAMSTARs)

*Kazuyoshi Suzuki¹, Milija Zupanski², Tkashi Dan¹, Steven Fassnacht², Hotaek Park¹, Hideki Kobayashi¹, Tetsuya Hiyama³ (1.Japan Agency for Marine-Earth Science and Technology, 2.Colorado State University, 3.Institute for Space-Earth Environmental Research, Nagoya University, Nagoya)

Keywords:Reanalysis, Data assimilation, Snow, Arctic environment

The JAMSTEC Arctic Regional reanalysis system (JAMSTARs) is a regional reanalysis framework based on 32 ensemble simulations covering areas from the Arctic to mid-latitudes. It routinely assimilates observational data from the US National Centers for Environmental Prediction (NCEP) PREPBUFR. The system provides tools to evaluate the impact of advanced land surface model parameterization and satellite retrieval on reanalysis accuracy. Its accuracy was assessed by comparing JAMSTARs with the ERA5 global reanalysis, MODIS snow cover, the US Climate Reference Network (USCRN), and US Snowpack Telemetry (SNOTEL) datasets. The results show that JAMSTARs achieves accuracy comparable to ERA5 for temperature, while it outperforms ERA5 in representing snowpack characteristics, such as snow depth. When assimilating AMSR2 Sea Surface Wind (SSW) data, the accuracy in polar regions improves, likely because the AMSR2 SSW data enhances the polar water cycle. In addition, a more sophisticated land surface model contributed to better surface reanalysis, especially regarding wind fields. The JAMSTARs system we developed can contribute to understanding extreme weather and permafrost changes in the Arctic and mid-latitudes, as well as provide a means to evaluate the impact of various observational data and land surface schemes. Eventually, this system is expected to serve as a tool for detailed monitoring of the rapidly changing Arctic environment, paving the way for the operation of Arctic Ocean routes and the utilization of related data.