关键词: 淮河流域, 夏季降水, 年代际变化, 大气环流异常

Abstract: Based on precipitation data of 642 stations in China and NCEP/NCAR reanalysis data during 1961-2016, the interdecadal variation characteristics of summer precipitation over the Huaihe River Basin and corresponding atmospheric circulation anomalies since 2000  were  analyzed, and the change of possible predictive signals around  the year 2000 was discussed. The results show that summer precipitation over the Huaihe River Basin had obvious interdecadal change, which was from the period of more precipitation during 2000-2008 to the period of less precipitation during 2009-2016, and the precipitation differences were significant between two periods. The atmospheric circulations during the two different precipitation periods were obviously different. During the period of more (less) precipitation, the high ridge (low trough) over the Lake Baykal was obvious, the low trough (high ridge) over the Ural mountains and the Sea of Okhotsk was obvious. And the South Asia high became weaker (stronger) and shifted westward (eastward-shifted), the East Asian Subtropical Westerly Jet Stream was weaker(stronger), the tropical easterlies jet was stronger (weaker). Meanwhile, during the periods of more (less) precipitation ,there  was  strong (weak) Somali cross-equatorial flow, Mascarene high and Australian high of southern hemisphere. The pre-winter North Pacific Oscillations (NPO) could still be a precursory signal of summer precipitation over the Huaihe River Basin. However, the interdecadal variation  of  relationship between the NPO and summer precipitation over the Huaihe River Basin had arisen around the year 2000. There was a significant negative correlation before 2000 and positive correlation after 2000. For both strong (weak) pre-winter NPO years before 2000 and weak (strong) pre-winter NPO years after 2000, the summer high ridge (low trough) over the Ural mountains and the Sea of Okhotsk was obvious, the summer low trough (high ridge) over the Lake Baykal was  obvious and the summertime western Pacific Subtropical High was located from South China sea to north Philippine(sea area near Taiwan), which influenced summer precipitation less (more) over the Huaihe River Basin.

Key words: Huaihe River Basin, summer precipitation, interdecadal variation, atmospheric circulation anomalies