Monthly-scale extended predictions using the atmospheric model coupled with a slab ocean

[摘要] Given the good persistence of sea surface temperature(SST) due to the slow-varying nature of the ocean, an atmospheric modelcoupled with a slab ocean model (SOM) instead of a 3-D dynamical ocean modelis designed as an efficient approach for extended-range predictions. Theprediction experiments from July to December 2020 are performed based on theWeather Research and Forecasting (WRF) model coupled to the SOM (WRF-SOM)with the initial and boundary conditions same as the WRF coupled to theRegional Ocean Model System (WRF-ROMS). The WRF-SOM is verified to havebetter performance of SSTs in the extended-range predictions than WRF-ROMSsince it avoids the complicated model biases from the ocean dynamics andseabed topography when extended-range predictions are made using a 3-Ddynamical ocean model. The improvement of SSTs can lead to the remarkableimpact on the response of the atmosphere from the surface to the upperlayer. Taking typhoon as an example of extreme events, the WRF-SOM canobtain comparable intensity predictions and slightly improved trackpredictions due to the improved SSTs in the initialized WRF-SOM system.Overall, the WRF-SOM can ensure the stability of extended-range predictionand reduce the demand for computing resources by roughly 50 %.

[学科分类] 土木及结构工程学