Physical decomposition principle of regional-scale atmospheric transient anomaly

摘要: In a mixed space-time domain, atmospheric variables can be decomposed into the zonal time-average climate symmetric part, the time-average climate asymmetric part, the zonal-average transient symmetric anomaly, and the transient asymmetric anomaly. The first two parts are forced by the seasonal solar radiation and land-sea distribution and linked to regular daily climate. The third part is caused from intra-seasonal to inter-annual tropical or polar heating variations and shows like the planetary-scale index cycle. The last part is complex as some atmospheric transient waves or regional-scale anomalies. The daily transient anomalies of atmospheric variables can be used to indicate some extreme weather events such as the regional persistent drought, heavy rainfall, lower temperature and hot days. We suggest that the weather map of transient anomalies could be applied in forecasts of extreme weather events.