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On recent interannual variability of the Arctic winter mesosphere: Implications for tracer descent
Author(s) -
Siskind David E.,
Eckermann Stephen D.,
Coy Lawrence,
McCormack John P.,
Randall Cora E.
Publication year - 2007
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 - 10.1029/2007gl029293
Subject(s) - stratopause , stratosphere , mesosphere , thermosphere , atmospheric sciences , atmosphere (unit) , gravity wave , environmental science , climatology , arctic , geology , polar vortex , depth sounding , troposphere , ionosphere , gravitational wave , geophysics , meteorology , physics , oceanography , astrophysics
Observations from the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) experiment on the NASA/Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite show an unusual vertical displacement of the winter Arctic stratopause in 2006 with zonal mean temperatures at 0.01 hPa (∼78 km) exceeding 250 K. By contrast, at the conventional stratopause location near 0.7 hPa (∼50 km), temperatures were unusually cold. Simulations with the NOGAPS‐ALPHA model suggest that these are coupled to an unusually warm and disturbed lower stratosphere that filtered out many of the gravity waves that normally break at and above 50 km. The model also shows that downward transport in the 2006 Arctic vortex was enhanced relative to 2005. These results might explain observations of enhanced upper atmospheric NO descending to the upper stratosphere in 2006 and highlights the importance of gravity waves in modulating the coupling of the upper atmosphere with the stratosphere.