We evaluated the performance of the Weather Research and Forecasting Model in simulating the boundary-layer structure at an urban site in Seoul on two clear summer days against observations made using a ceilometer, a Doppler wind lidar, and a microwave radiometer. The planetary boundary-layer height (PBLH) was estimated from two different methods using observations: the ceilometer-based method (CBM) and bulk Richardson number method (BRM). The maximum PBLH was well captured by the model but PBLH was underestimated in the late afternoon and evening. To examine the cause for underestimation of PBLH in the evening, we compared the wind and virtual potential temperature structure between the simulation and observations. The model captured the timing of the sea breeze well, but it considerably overestimated the intensity of the simulated sea breeze, resulting in an overestimated cold advection by a sea breeze. The effect of the overestimated cold advection on evening PBLH was greater when the sea breeze arrived in the late afternoon and hence the vertical extent of the sea breeze was shallow. This study underscores the importance of accurately simulating the sea breeze for PBLH prediction in the evening, over the inland urban areas under sea breeze penetration.

我们通过使用云高仪，多普勒风激光雷达和微波辐射计进行的观测，评估了天气研究与预报模型在模拟两个晴朗的夏日首尔市区边界层结构时的性能。行星边界层高度（PBLH）是使用观测值从两种不同的方法估算出来的：基于云高仪的方法（CBM）和体理查森数方法（BRM）。该模型很好地捕获了最大的PBLH，但在午后和傍晚却低估了PBLH。为了研究晚上低估PBLH的原因，我们在模拟和观测之间比较了风和虚拟的潜在温度结构。该模型很好地捕捉了海风的时机，但它大大高估了模拟海风的强度，导致海风高估了冷平流。当海风在下午晚些时候到达时，高估的平流对晚上PBLH的影响更大，因此海风的垂直范围很浅。这项研究强调了在海风渗透下的内陆城市地区，准确模拟海风对晚上进行PBLH预报的重要性。