CLIMATIC REGIME CHANGE IN THE ASIAN PACIFIC REGION, INDIAN AND SOUTHERN OCEANS AT THE END OF THE 20TH CENTURY

Abstract

Multiple scale climate variability in Asia of temperate and high latitudes, Pacific, Indian and South Oceans, their features and linkages are studied by using statistical analyses of monthly mean time series of Hadley, Reynolds SST, surface net heat flux (Q), atmospheric pressure (SLP), air temperature (SAT) from NCEP NCAR reanalyses (1948-2015). Three multidecadal climatic regimes were revealed for the whole area studied by using cluster analyses via Principal Components of differences between values of Q, SLP, SAT in tropical and extratropical regions of the Asian Pacific, Indian and Southern Oceans. The climate regime change in 70s of the 20th century in this area is confirmed by this method. It is also found that the climate regime is significantly changed at the end of the 20th century in both same area and World Ocean. The characteristic features of recent climate regime after 1996-1998 are SLP increase in the central extratropic area of Indian Ocean, North and South Pacific being prevailing in boreal winter. It is accompanying SLP increase and precipitation decrease in South Siberia and Mongolia prevailing in boreal summer. Inversed SLP and precipitation anomaly associated with increase of cyclone activity and extreme events in the land-ocean marginal zones including Southern Ocean, eastern Arctic, eastern Indian, western and eastern Pacific margins. It is known that low frequency PDO phase is also changed at the same time.