Factors and Mechanisms Affecting the Air Temperature Distribution on a Clear Winter Night in a Snow-Covered Mesoscale Plain

摘要

?There is an increasing need for accurate winter agrometeorological forecasts, which is facilitated by a better understanding of the evolution process of nighttime air-temperature distribution. However, studies on how air-temperature distributions evolve in mesoscale plains have been limited. To clarify how the low temperatures in winter nights form, we analyzed the effects of topography and boundary-layer wind on the temperature distribution of the Tokachi region for a winter night using numerical simulations by the Japan Meteorological Agency Nonhydrostatic Model (JMA-NHM) with horizontal grid spacing of 2 and 5 km. We also analyzed vertical profiles of boundary-layer atmospheric conditions.