The effect of the Qinghai-Xizang Plateau anomalous heating on the downstream atmospheric circulation is explored from May to August by using the Regional Climate Model Version 4.0, and a series of numerical experiments are performed with three different kinds of anomalous heating rates over the plateau for each month. The results are: (1) After 12 days when the atmosphere over the plateau is heated with the rate of 4 K·d-1 in May, the geopotential height anomaly on 500 hPa is positive near the Okhotsk Sea and negative in Northeast China and to the south of the Kamchatka Peninsula, forming a suspected wave train; however, it turns to be a dipole pattern on 200 hPa, with positive in the west and negative in the east. When it comes to June, the construction of this wave train becomes more evident, with a complete wave like the Okhotsk-Japan (OKJ) pattern appearing on 200 hPa, which includes a positive anomaly over the plateau, a negative anomaly to the south of Lake Baikal, a positive anomaly around the Okhotsk Sea and a negative anomaly to the east of Japan. The negative geopotential height anomaly on 500 hPa over the plateau indicates the baroclinic effect of this anomalous heating. (2) There are no similar wave structures on both 200 hPa and 500 hPa during other months. In July, the geopotential height anomaly is always negative from Mongolia to the Okhotsk Sea and to the east of Japan on both 200 hPa and 500 hPa. In August, the geopotential height anomaly turns to be positive off the east coast of Japan, and the negative anomaly near the Okhotsk Sea remains to be unchanged. (3) Sensitivity experiments of different anomalous heating rates show that, with the strengthening of anomalous heating over the plateau, the geopotential height anomalies tend to be almost proportionally increased at each point along the wave track on 200 hPa in June. (4) In addition, the analysis of ray tracing shows that the ray paths in May are similar to those in June, and the simulation route lies between the ray paths with zonal wavenumber 3 and 4, nearer to the one with zonal wavenumber 4. However, in July and August, the ray paths with three different kinds of zonal wavenumber are close to each other, which are very different from those in May and June.
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