资源环境科技发展态势分析平台

The effects of a cyclone-induced sea surface temperature (SST) anomaly in the Sea of Japan on following cyclones were investigated using a regional numerical model. The model was conducted with and without an SST anomaly due to cooling from a single extratropical cyclone in winter. Twenty-six pairs of sensitivity experiments demonstrated that cyclones were not always sensitive to the SST anomaly. The low-level trough (strong northwesterly winds) affected cyclone sensitivity via a cold air intrusion over the Sea of Japan. A strong (weak) cold air intrusion formed a relatively unstable (stable) and higher (lower) convective layer and the concentration of cyclone paths over the oceans, making the cyclones sensitive to the underlying SST. Two specific cyclones were analyzed to demonstrate two distinct patterns (wave-like and path shifting, respectively) in cyclone modulations revealed in the wavelet spectra. The wave-like pattern was formed by the superposition of multiple anomalous waves with different periods and scales, which originated from upper-level potential vorticity anomalies and temperature advection. The path-shifting pattern was caused by the diabatic heating-induced potential vorticity anomalies, which were supplied by the intense heat and moisture from the regions surrounding the Sea of Japan. Therefore, a cyclone can modulate a following cyclone by reducing the SST over the Sea of Japan; however, the modulation can vary in different ways, depending on the atmospheric background and dynamics of the cyclone development.