The Influence of the Madden–Julian Oscillation on Northern Hemisphere Winter Blocking

• DOI: 10.1175/jcli-d-15-0502.1
• Publication Date: 2016-03-29T16:53:30Z
• Authors: Stephanie A. Hend...; Eric D. Maloney; Elizabeth A. Barnes
• Keywords: Madden–Julian oscillation; Blocking (statistics); Anticyclone; Teleconnection

Abstract The persistent and quasi-stationary nature of atmospheric blocking is associated with long-lasting extreme weather conditions that influence much the Northern Hemisphere during boreal winter. Madden–Julian oscillation (MJO) has been previously shown to important factors for blocking, including Rossby wave breaking North Atlantic Oscillation (NAO). However, extent which MJO influences across not yet fully understood. Utilizing a two-dimensional index, composites Pacific, Atlantic, European are generated relative phase. In west central all phases demonstrate significant changes in particularly at high latitudes. A decrease east Pacific occurs following phase 3 MJO, characterized by enhanced convection over tropical East Indian Ocean suppressed Pacific. opposite-signed heating 7 followed increase blocking. follows 4, an after 6. 6 hypothesized result from two preexisting conditions: 1) anomalous anticyclone 2) preceding negative Pacific–North American (PNA) pattern initialized influenced heating.