Shelters used to protect air temperature sensors from solar radiation induce a measurement error. This work presents a semi-empirical model based on meteorological variables to evaluate this error. The model equation is based on the analytical solution of a simplified energy balance performed on a naturally ventilated shelter. Two main physical error causes are identified from this equation: one is due to the shelter response time and the other is due to its solar radiation sensitivity. A shelter intercomparison measurement campaign performed by the World Meteorological Organization (WMO) is used to perform a non-linear regression of the model coefficients. The regression coefficient values obtained for each shelter are found to be consistent with their expected physical behavior. They are then used to simply classify shelters according to their response time and radiation sensitivity characteristics. Finally, the ability of the model to estimate the temperature error within a given shelter is assessed and compared to the one of two existing models (proposed by Cheng and by Nakamura). For low-response-time shelters, our results reduce the root mean square error by about 15% (0.07 K) on average when compared with other compensation schemes.

A sea‐breeze (SB) initiation under land synoptic wind near a peninsula is analyzed by means of LiDAR measurements and large‐eddy simulations (LES) using the Weather Research and Forecasting (WRF) framework. In the simulation results, local SBs initiated over several coast segments converge in the morning and form a front near the peninsula. As the marine atmospheric boundary layer is stably stratified, the front generates an undular bore featuring gravity waves (GW). Despite the absence of cloud signatures, the GW are detected in the LiDAR horizontal scans, providing a direct observation. The GW have a low propagation speed, a small wavelength, and their amplitude decreases with increasing distance from the coastline. The GW amplitude increases with the strengthening of the local convergence and then decreases when the local SBs merge into a regional SB. The turbulent kinetic energy (TKE) profile in the SB without GW forms a peak in the center of the SB cell. Within the GW, a significant part of the TKE calculated from simulation results is related to the GW horizontal motion. A method is proposed to extract only the part originating from the turbulent field. A peak in the TKE profile is also observed, and its intensity is 50%–100% higher near the crests than at the troughs. Analysis of the TKE budget demonstrates that, at the peak height, the shear production is positive only in the ascending phase of the GW, and that the TKE maximum at the crests mainly results from the advection process.