Heidelberg 2015 – wissenschaftliches Programm
UP 4.12: Poster
Mittwoch, 25. März 2015, 10:45–19:45, G/Foyer
Sensitivity of equatorial atomic oxygen in the MLT to the 11-year and 27-day cycles of solar activity — •Olexandr Lednyts’kyy and Christian von Savigny — Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany
Atomic oxygen concentration ([O]) profiles are retrieved from O(1S-1D) nightglow emission rates provided by SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) on Envisat from August 2002 to April 2012 daily at approximately 22:00 local solar time. These O retrievals are used to assess the sensitivity of O in the mesosphere-lower thermosphere (MLT) region to the 11-year and 27-day solar activity cycles. The 11-year and 27-day solar cycle responses in SCIAMACHY O are statistically significant and of the same order. Our results correspond well to the 11-year solar cycle response in O volume mixing ratios found in simulations with the NCAR Whole Atmosphere Community Climate Model, version 3 (WACCM3), and the three-dimensional Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA) model. Solar forcing causes increased photodissociation of O2 and raises the O abundance consequently.