###### Abstract  
This study aims to improve the performance of the Weather Research and Forecasting (WRF) model in the sea breeze circulation using the micro-Genetic Algorithm (micro-GA). We found the optimal combination of four physical parameterization schemes related to the sea breeze system, including planetary boundary layer (PBL), land surface, shortwave radiation, and longwave radiation, in the WRF model coupled with the micro-GA (WRF-uGA system). The optimization was performed with respect to surface meteorological variables (2 m temperature, 2 m relative humidity, 10 m wind speed and direction) and a vertical wind profile (wind speed and direction), simultaneously for three sea breeze cases over the northeastern coast of South Korea. The optimized set of parameterization schemes out of the WRF-uGA system includes the Mellor-Yamada-Nakanishi-Nino level-2.5 (MYNN2) for PBL, the Noah land surface model with multiple parameterization options (Noah-MP) for land surface, and the Rapid Radiative Transfer Model for GCMs (RRTMG) for both shortwave and longwave radiation. The optimized set compared with the various other sets of parameterization schemes for the sea breeze circulations showed up to 29 % for the improvement ratio in terms of the normalized RMSE considering all meteorological variables. ao 2021 11 11221. [[https://doi.org/10.3390/app112311221](https://doi.org/10.3390/app112311221)]([https://doi.org/10.3390/app112311221](https://doi.org/10.3390/app112311221))  
15 September 2021 18 November 2021 26 November 20  
breezes in Yeongdong [14], prominent sea breezes appeared for 268 days during April, May, and June from 2009 to 2018. Therefore, sea breezes play a vital role in local weather as it affects weather elements, e.g., temperature, humidity, and wind, in Yeongdong. Thus, various studies are needed to improve the prediction skill of the numerical simulation of the sea breeze in Yeongdong. Recently, various numerical sensitivity experiments of the sea breeze circulations have been conducted using mesoscale models, mainly on the performance of several parameterization schemes in a specific physical process (e.g., cumulus, land surface, or planetary boundary layer (PBL)). For example, among several PBL schemes widely used in the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5), [PERSON] et al. [15] showed that the Blackadar scheme had the best performance in simulating sea breezes over a southeastern coastal area in India. Using the Weather Research and Forecasting (WRF) model, [PERSON] et al. [16] confirmed that the wind speed and offshore extent of sea breezes are sensitive to the adopted PBL scheme at scales similar to the southern North Sea. Impact of three land surface models (LSMs), coupled to WRF, in simulating the sea breeze circulation was also investigated, showing the most realistic simulations by the Noah LSM with multiple parameterization options (Noah-MP), followed by the Noah LSM and the 5-layer soil thermal diffusion scheme [17]. Other studies examined the combined \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Station** & **Latitude (\({}^{\circ}\)N)** & **Longitude (\({}^{\circ}\)E)** & **Altitude (m)** \\ \hline CheongHo (CH) & 38.19 & 128.60 & 3.65 \\ YangYang (YY) & 38.09 & 128.63 & 4.31 \\ JuMunjin (JM) & 37.90 & 128.82 & 8.94 \\ GangMun (GM) & 37.79 & 128.93 & 6.61 \\ Gangneung-Seongsan (GS) & 37.73 & 128.78 & 455.97 \\ OkGye (OG) & 37.61 & 129.03 & 58.41 \\ SamCheok (SC) & 37.45 & 129.17 & 68.48 \\ GungChon (GC) & 37.33 & 129.27 & 14.07 \\ BukGangNeung (BGN) & 37.81 & 128.86 & 75.24 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Main attributes of meteorological stations used for optimization and validation. See the station locations on the map in Figure 1b. Figure 1: **(a)** Computational domain in WRF having triple nesting with horizontal resolution of 9 km (d01), 3 km (d02), and 1 km (d03) and (**b**) locations of the observational stations in d03. Station GangNeung (GN; in red) is used only for selecting the sea breeze cases.