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The Influence of the Madden–Julian Oscillation on Northern Hemisphere Winter Blocking
- Source :
- Journal of Climate. 29:4597-4616
- Publication Year :
- 2016
- Publisher :
- American Meteorological Society, 2016.
-
Abstract
- The persistent and quasi-stationary nature of atmospheric blocking is associated with long-lasting extreme weather conditions that influence much of the Northern Hemisphere during boreal winter. The Madden–Julian oscillation (MJO) has been previously shown to influence important factors for blocking, including Rossby wave breaking and the North Atlantic Oscillation (NAO). However, the extent to which the MJO influences blocking across the Northern Hemisphere is not yet fully understood. Utilizing a two-dimensional blocking index, composites of North Pacific, North Atlantic, and European blocking are generated relative to MJO phase. In the west and central Pacific, all MJO phases demonstrate significant changes in blocking, particularly at high latitudes. A significant decrease in east Pacific and Atlantic blocking occurs following phase 3 of the MJO, characterized by enhanced convection over the tropical East Indian Ocean and suppressed convection in the west Pacific. The opposite-signed MJO heating during phase 7 is followed by a significant increase in east Pacific and Atlantic blocking. A significant decrease in European blocking follows MJO phase 4, with an increase after phase 6. The phase 6 European blocking is hypothesized to result from two preexisting conditions: 1) an anomalous anticyclone over the Atlantic and 2) a preceding negative Pacific–North American (PNA) pattern initialized and influenced by MJO heating.
- Subjects :
- Atmospheric Science
010504 meteorology & atmospheric sciences
Blocking (radio)
Rossby wave
Northern Hemisphere
Madden–Julian oscillation
010502 geochemistry & geophysics
Block (meteorology)
01 natural sciences
Latitude
North Atlantic oscillation
Climatology
Geology
0105 earth and related environmental sciences
Teleconnection
Subjects
Details
- ISSN :
- 15200442 and 08948755
- Volume :
- 29
- Database :
- OpenAIRE
- Journal :
- Journal of Climate
- Accession number :
- edsair.doi...........38fbe4890f28fa3209ae6180773a5e52