Denitrification, dehydration and ozone loss during the 2015/2016 Arctic winter

Abstract

Abstract. The 2015/2016 Arctic winter was one of the coldest stratospheric winters

Comparison of ECHAM5/MESSy Atmospheric Chemistry (EMAC) simulations of the Arctic winter 2009/2010 and 2010/2011 with Envisat/MIPAS and Aura/MLS observations

“…Although not explicitly discussed, we have also performed comparisons for other trace gases, such as O 3 . As found in Khosrawi et al (2017) for the Arctic winter 2015/2016, a very good agreement between the simulated and measured O 3 is also found here at the beginning of the winter. However, during the course of the winter when ozone destruction and descent become important, an increase of the differences is found.…”

“…The largest relative differences (up to 45 %) are found in mid-January, when the PSCs have their peak occurrence. The underestimation of HNO 3 in the model simulation also affects chlorine activation and ozone loss, but other factors like the underestimation of transport in the model and inaccuracies in the partitioning between chlorine species at high solar zenith angles as discussed for the Arctic winter 2015/2016 in Khosrawi et al (2017) also play a role.…”

“…In our study the focus is on PSC volume density, temperature, and HNO 3 . Further (qualitative) comparisons with additional trace gases (O 3 , ClO, and H 2 O) were performed in another study for the Arctic winter 2015/2016 (Khosrawi et al, 2017) where EMAC simulations were compared with observations from Aura/MLS and the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) performed on board the High Altitude and LOng-range Research Aircraft (HALO).…”

Airborne limb-imaging measurements of temperature, HNO<sub>3</sub>, O<sub>3</sub>, ClONO<sub>2</sub>, H<sub>2</sub>O and CFC-12 during the Arctic winter 2015/2016: characterization, in situ validation and comparison to Aura/MLS

“…During these campaigns, the instrument was constantly improved , the data processing was revised Guggenmoser et al, 2015), the level 2 products were validated Woiwode et al, 2015;Ungermann et al, 2015), and GLORIA data proved to be useful for model validation (Khosrawi et al, 2017) and case studies Krisch et al, 2017). Improvements to the instrument (reduced aero-acoustic noise in the spectra) compared to the results of Woiwode et al (2015) also increase the quality of the measured infrared spectra, resulting in different characteristics of the retrieved temperature and trace gas profiles.…”

Toward a Reanalysis of Stratospheric Ozone for Trend Studies: Assimilation of the Aura Microwave Limb Sounder and Ozone Mapping and Profiler Suite Limb Profiler Data

“…The year 2016 was selected for the test experiments since it featured several unusual events occurring in or affecting the stratosphere. Of particular interest are the following: The boreal winter of 2015/2016 characterized by exceptionally cold and strong polar vortex and near‐record ozone loss due to heterogeneous chemistry terminated by a relatively early final warming that began on 6 March 2016 (Khosrawi et al, ; Manney & Lawrence, ; Matthias et al, ). The unusual disruption of the quasi‐biennial oscillation (QBO; Osprey et al, , Newman et al, ) that, combined with a very strong El Niño event, had a significant impact on tracer transport in the lower stratosphere (Diallo et al, ; Tweedy et al, ). …”