Climatological anomalies of 500 hPa height fields for heavy rainfalls over the Huaihe River Basin

ABSTRACT: The signal field method was adopted in an effort to effectively extract climatological anomalies from the 500 hPa height fields for the heavy rainfalls over the Huaihe River Basin (HRB) in 2003, 2005 and 2007. The results show that the heavy rainfalls were all associated with a similar anomaly pattern of the 500 hPa height signal fields: both the west of the Lake Baikal and the south of the HRB were dominated by significant positive signals; the vicinity of the HRB was covered by negative signals; the positive-negative height signals established a tripole of “+ − +” from mid-high to low latitudes. In addition, the forming and collapsing of this tripole to some extent corresponded to the heavy rainfall processes of the HRB.