To improve surface mass balance (SMB) estimates for the Greenland Ice Sheet (GrIS), we developed a 5&thinsp;km resolution regional climate model combining the Japan Meteorological Agency Non-Hydrostatic atmospheric Model and the Snow Metamorphism and Albedo Process model (NHM-SMAP) with an output interval of 1&thinsp;h, forced by the Japanese 55year Reanalysis (JRA-55). We used in situ data to evaluate NHM-SMAP in the GrIS during the 2011&ndash;2014 mass balance years. We investigated two options for the lower boundary conditions of the atmosphere, an "off-line" configuration using snow/firn/ice albedo and surface temperature data from JRA-55 and an "on-line" configuration using values from SMAP. The on-line configuration improved model performance in simulating 2&thinsp;m air temperature, suggesting that the surface analysis provided by JRA-55 is inadequate for the GrIS and that SMAP results can better simulate snow/firn/ice physical conditions. It also reproduced the measured features of the GrIS climate, diurnal variations, and even a meso-scale strong wind event. In particular, it reproduced the GrIS surface melt area extent well. Sensitivity tests showed that the choice of calculation schemes for vertical water movement in snow and firn has an effect as great as 200&thinsp;Gt&thinsp;year<sup>–1</sup> in the GrIS-wide accumulated SMB estimates; a scheme based on the Richards equation provided the best performance.
Niwano, M., Aoki, T., Hashimoto, A., Matoba, S., Yamaguchi, S., Tanikawa, T., … Hori, M. (2018). NHM-SMAP: Spatially and temporally high-resolution nonhydrostatic atmospheric model coupled with detailed snow process model for Greenland Ice Sheet. Cryosphere, 12(2), 635–655. https://doi.org/10.5194/tc-12-635-2018