Possible Linkage between Spring Surface Sensible Heat Flux Anomalies over the Mid-High Latitudes of the Eurasian Continent and Summer Precipitation in the Middle-Lower Reaches of the Yangtze River

On the basis of daily precipitation observations at 743 stations in China and monthly surface sensible heat flux data from the European Centre for Medium-Range Weather Forecasts reanalysis data (ERA40 and ERA-interim) as well as that of NCEP/NCAR reanalysis data, the physical mechanism and possible linkage between spring surface sensible heat flux anomalies in the mid-high latitudes of the Eurasian Continent and summer precipitation over the middle-lower reaches of the Yangtze River is analyzed in this study. The results show a significant positive correlation between them. Further analysis indicates that strong spring surface sensible heating in the mid-high latitudes of the Eurasian Continent always exists concurrently with the eastward shifted and strengthened East Asia subtropical westerly jet. In such a situation, evidently anomalous ascension and divergence of the water vapor transport result in increased summer precipitation over the middle-lower reaches of the Yangtze River. On the contrary, weak surface sensible heating tends to cause less precipitation in this area. Therefore, the spring surface sensible heat flux anomalies over the Eurasian Continent in the mid-high latitudes can be a potential predictor for the summer precipitation prediction in the middle-lower reaches of the Yangtze River.