Impact of Initial Soil Temperature and Moisture on the Temperature and Relative Humidity at 2 m in the WRF Model over North China in Winter

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  • 1. Key Laboratory of Meteorology and Ecological Environment of Hebei ProvinceShijiazhuang 050021HebeiChina
    2. China Meteorological Administration Xiongan Atmospheric Boundary Layer Key LaboratoryXiongan New Area 071800HebeiChina
    3. Hebei Provincial Institute of Meteorological SciencesShijiazhuang 050021HebeiChina
    4. State Key Laboratory of Severe WeatherChinese Academy of Meteorological SciencesBeijing 100081China

Online published: 2025-12-31

Abstract

The effects of initial soil temperature and moisture were explored by performing a series of 84-hour numerical simulations form 10 to 25 December 2023using the WRF model with soil temperature and moisture initialized with CMA-GFS forecasts and the China Meteorological Administration Land Data Assimilation Sys‐ temCLDASanalysis respectively. It showed that the relative humidityRH2mand the temperatureT2mat 2 m were poorly during the first 21-hour integration and getting better during the following time integration ini‐ tialized with CLDAS than that with CMA-GFSwith a maximum root mean square errorRMSEdecrease of 8. 3% and 10% respectively. Further diagonosis indicated that the first 21-hour integration usually a accompanied with more sensible and latent heat fluxes in case of the soil temperature and moisture initialized with CLDAS. It means that the model would take a longer spin-up time during which any satisfiable forecasted T2m and RH2m might not be gottendue to the in consistanece in initial conditions which came from the different source datasets containing some more reliable variables although. Spatiallywhen the model was initialized with CLDASit rep‐ resented much more favourable with smaller negative deviation of RH2m and positive deviation of the daily max‐ imum T2mwhich maximally decreased by 8% and 1. 5 °C in Henan respectivelyand unfavourable with larger positive deviation of the daily minimum T2m in the southern region of Shanxi and central Hebei. Whereasit rep‐ resented pretty well performance of daily maximum and minimum T2m and bad performance of RH2m with larg‐ er negative deviation in the northern region of northern Shanxi and northern Hebei. Among groups of initial soil conditionsthe moister and colder initial soil group had the best forecasting performance of T2m which is tightly closed to the observationand the moister and warmer initial soil group has the worst although the T2m differ‐ ence between the simulations initialized with CLDAS and CMA-GFS is small. Compared with the initial soil tem‐ peraturethe initial soil moisture has a greater impact on T2m. The drier initial soil would lead to a better fore‐ casting performance of daily minimum T2maccompanied with larger sensible heat flux and smaller latent heat flux in the integration.

Cite this article

ZHANG Lin, ZHANG Weihong, YIN Jinfang, DING Minghu . Impact of Initial Soil Temperature and Moisture on the Temperature and Relative Humidity at 2 m in the WRF Model over North China in Winter[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00058

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