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Recent Weakening in the Stratospheric Planetary Wave Intensity in Early Winter
Author(s) -
Hu Dingzhu,
Guo Yipeng,
Guan Zhaoyong
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl082113
Subject(s) - atmospheric sciences , troposphere , climatology , environmental science , sudden stratospheric warming , potential vorticity , kelvin wave , zonal and meridional , rossby wave , geology , polar vortex , vorticity , physics , meteorology , vortex
Previous studies have reported that the tropospheric climate shifted around the 2000s, but the recent trend in the stratospheric wave intensity (SWI) is still unclear. The results in this study show that the SWI in December during 2001–2015 weakens, which is opposite to that during 1979–2000, implying a shift around the 2000s. The weakened SWI is dominated by its wave number‐1 component, which is related to the wave propagation impeded by the decreased refractive index at high latitudes and the weakened wave activity in the troposphere. Changes in refractive index are mainly contributed by changes in the meridional potential vorticity gradient via the barotropic term. This shift in the wave number‐1 waves leads to a shift in the stratospheric Arctic temperature, that is, warming (cooling) during 1979–2000 (2001–2015), implying that similar shifting phenomena may appear regardless of the continued greenhouse gas emissions.