In this study, an index for the variability of mesoscale sea surface temperature (SST) anomalies over the Kuroshio and Oyashio confluence region (KOCR) is proposed based on the high‐resolution SST data set. The positive phase of the new index indicates that the mesoscale SST anomalies are strong and feature double peaks of variance within the KOCR, and the negative phase of the index denotes weak mesoscale SST anomalies and a broader single peak of variance. Composite analysis is conducted on the relation between the variability of mesoscale SST and the North Pacific storm track. The mechanism behind the relation is then investigated. We find that the storm track is shifted southwards (northwards) during the positive (negative) phase of the index. The variability of mesoscale SST impacts first the turbulent heat fluxes out of the ocean, changing the near‐surface baroclinicity with the large‐scale zonal wind. The baroclinic energy conversion resembles the baroclinicity anomaly, modulating the anomaly of the storm track along the southern side of its climatological peak.

Concurrence of temperature inversion (TI) and humidity inversion (HI) is a particular configuration of the atmospheric boundary layer with important implications for early warning of fog formation. With a microwave radiometer device deployed in a 2‐month winter campaign at a coastal island in Qingdao, China, we here examine the relationship between TI and HI, and investigate the underneath mechanisms. Cases of temperature inversion are further divided into surface‐based temperature inversion (SBTI) and elevated temperature inversion (ETI), which show different relationship with HI. SBTI typically occurs at night with its strength significantly and positively correlated with HI. ETI also shows a high degree of temporal overlap with HI, but its strength has no obvious relationship with HI. The main explanation for this phenomenon is that ETI may block the vertical diffusion of water vapor, resulting in the formation of HI.

Based on the regional climate model RegCM4.5 driven by National Centers for Environmental Prediction (NCEP) reanalysis, the influence of cumulus convection schemes (CCSs) on the winter North Pacific storm track (WNPST) is investigated. It is found that the climatology, interannual variation, spatial modes and characteristic indices of the WNPST are extremely sensitive to the choice of CCS. Among the selected CCSs, WNPST climatology and interannual variation in the Kuo scheme are better than in other CCSs, with a smaller root mean square error. The WNPST spatial modes and strength indices in the Kuo and Grell schemes are more consistent with NCEP reanalysis. The Kuo scheme has a stronger ability to simulate the WNPST latitude index and the interannual variation of winter characteristic indices. In addition, we attempt to reveal the possible reasons for the different performances of CCSs from the viewpoint of baroclinic energy conversion (BCEC). It is found that the energy conversion from the mean available potential energy to the eddy available potential energy (BCEC1) has no significant difference among the Kuo, Grell and Emanuel schemes, while energy conversion from the eddy available potential energy to eddy kinetic energy (BCEC2) in the Kuo scheme is obviously better than other CCSs, which means that the differences in BCEC2 among these CCSs may be one of the key reasons affecting the simulation results of the WNPST.

Inverse energy cascade (IEC), where energy moves from small to large eddies, has been debated, with limited observational evidence. This study used 19 months of Doppler Lidar data from Qingdao, China, to examine IEC associated with gusts. We found IECs occurred 15% of the time at 50 m height. When near‐surface wind speeds exceeded 11 m·s⁻¹, IEC frequency and intensity increased, indicating that strong winds are a critical driver of IEC. This study suggests that the reduction in the drag coefficient under high wind conditions may generate IEC and gusts, consequently influencing energy transfer throughout the boundary layer and lower troposphere. Analysis using the four‐quadrant model revealed IECs are linked to changes in momentum from ejections and inward interactions, even in weak background fields. The study supports that IECs are more prevalent and highlights their role in the lower atmosphere, contributing to an improved understanding of land‐atmosphere coupling.