First detection of a brief mesoscale elevated stratopause in very early winter

• Published in: Geophysical Research Letters
• Main Authors: García Comas, Maia, Funke, Bernd, López-Puertas, Manuel, González-Galindo, F., Hoepfner, M.
• Other Authors: Ministerio de Ciencia, Innovación y Universidades (España), European Commission
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2020
• Subjects: Arctic; Merra; Midwinter
• Online Access: http://hdl.handle.net/10261/205312; https://doi.org/10.1029/2019GL086751; https://doi.org/10.13039/501100000780

Elevated stratopauses are typically associated with prolonged disturbed conditions in the Northern Hemisphere polar winter. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Microwave Limb Sounder (MLS) observed a short-lived and highly zonally asymmetric stratopause at mesospheric altitudes in November 2009, the earliest in the season reported so far. The Arctic climatological winter stratopause vanished, and MIPAS and MLS measured temperatures of 260 K at 82 km and 250 K at 75 km, respectively, in a region smaller than in typical midwinter elevated stratopause events. Planetary wave activity was initially high. Zonal mean zonal winds and the poleward temperature gradient northward of 70°N stayed reversed during 7 days, but the mesosphere did not cool. Wave activity dropped until the eastward stratospheric winds resumed and a strong vortex restored in the mesosphere. The stratopause emerged at high altitudes, staying there for 2–5 days. It was accompanied by enhanced downward transport. It took the stratopause 9 days to move down to its typical winter altitudes. ©2020. American Geophysical Union. All Rights Reserved. The IAA team acknowledges financial support from the State Agency for Research of the Spanish MCIU through Project ESP2017?87143-R, the ?Center of Excellence Severo Ochoa? award to the IAA-CSIC (SEV-2017-0709), and EC FEDER funds. MIPAS data sets can be accessed upon request online (https://www.imk-asf.kit.edu/english/308.php). We thank the Global Modeling and Assimilation Office for providing MERRA-2 data and the MLS science and data processing teams for providing MLS data publicly through the NASA Goddard Space Flight Center Earth Sciences (GES) Data and Information Services Center.