Arctic Oscillation and Precipiation over the North Pacific

Miao HU
Beijing Normal University
Seminar Date: 
6. December 2012 - 12:30 - 13:00
Lecture room, Ground Floor, NERSC

The relationships between the winter (January-March) Arctic Oscillation and precipitation over the tropical Northern Pacific during the period of 1979 to 2011 is presented based on the monthly GPCP (Global Precipitation Climatology Project) data and NCEP/NCAR Reanalysis, after subtracting ENSO signals from all datasets. The sliding correlation analysis demonstrates there is a prominent weakening in the AO-precipitation relation around the year 1990. In the total 33 years a high (low) AO phase more likely accompanies with a stronger (weaker) precipitation in the subtropical Pacific, and the significant correlation area ranges from 10°N-30°N, 150°E-190°W. During the year 1979 to 1989, the positive correlations over the tropical Pacific are significant and widely-ranged; however, the correlations become weak over the whole region, and even negative over the central Pacific after 1990.