Simulation and Dynamical Prediction of the Summer Asian–Pacific Oscillation and Associated Climate Anomalies by the NCEP CFSv2

AbstractThe Asian–Pacific Oscillation (APO) is a dominant teleconnection pattern linking the climate anomalies over Asia, the North Pacific, and other regions including North America. The National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2) successfully simulates many summer-mean features of the upper-tropospheric temperature, the South Asian high, the westerly and easterly jet streams, and the regional monsoons over Asia and Africa. It also well simulates the interannual variability of the APO and associated anomalies in atmospheric circulation, precipitation, surface air temperature (SAT), and sea surface temperature (SST). Associated with a positive APO are a strengthened South Asian high; a weakened extratropical upper-tropospheric westerly jet stream over North America; strengthened subtropical anticyclones over the Northern Hemisphere oceans; and strengthened monsoons over North Africa, India, and East Asia. Meanwhile, increased precipitation is found over t...