Stratospheric ozone loss in the 1996/1997 Arctic winter: Evaluation based on multiple trajectory analysis for double‐sounded air parcels by ILAS

Abstract

[1] Quantitative chemical ozone loss rates and amounts in the Arctic polar vortex for the spring of 1997 are analyzed based on ozone profile data obtained by the Improved Limb Atmospheric Spectrometer (ILAS) using an extension of the Match technique. In this study, we calculated additional multiple trajectories and set very strict criteria to overcome the weakness of the satellite sensor data (lower vertical resolution and larger sampling air mass volume) and to identify more accurately a double-sounded air mass. On the average inside the inner edge of the vortex boundary (north of about 70°N equivalent latitude), the local ozone loss rate was 50-80 ppbv/day at the maximum during late February between the levels of 450 and 500 K potential temperatures. The integrated ozone loss during February to March reached 2.0 ± 0.1 ppmv at 475-529 K levels, and the column ozone loss between 400 and 600 K during the 2 months was 96 ± 0.3 DU. Using a relative potential vorticity (rPV) scale, the vortex was divided into some rPV belts, and it was shown that the magnitude of the ozone loss increased gradually toward the vortex center from the edge. The maximum ozone loss rate of 6.0 ± 0.6 ppbv/sunlit hour near the vortex center was higher than near the vortex edge by a factor of 2-3. When we expanded the area of interest to include all the data obtained inside the vortex edge (north of about 65°N equivalent latitude), the local ozone loss rate was about 50 ppbv/day at the maximum. This value is slightly larger than that estimated by the Match analysis using ozonesondes for the same winter by $10 ppbv/day. Temperature histories of double-sounded air parcels indicated that the extreme ozone loss in the innermost part of the vortex was observed when the air parcel experienced temperatures below T NAT during the two soundings and had experienced temperatures near T ice in the 10 days prior to the first sounding. These facts suggest that the high ozone loss rate deep inside the vortex in the 1997 Arctic early spring correlates with the presence of type Ia polar stratospheric clouds (PSCs).

Ozone loss and chlorine activation in the Arctic winters 1991-2003 derived with the tracer-tracer correlations

“…In 1996-1997, MLS calculations of ozone loss stopped at the end of February 1997. However, in March significant ozone loss can be expected Terao et al, 2002). Although, ozone loss deduced with the two approaches fits very well in this winter considering the entire vortex, MLS ozone loss is significantly smaller considering the vortex core.…”

“…Such values are in agreement with the moderate ozone loss within the range of uncertainty deduced from ILAS 0.5-1.0 ppmv (±0.2 ppmv) and HALOE 0.9-1.4 ppmv (±0.2 ppmv) at the 475 K level . Further calculations of ozone loss were performed by the Match technique based on ILAS observations for the winter 1996-1997 (Terao et al, 2002). There, the integrated ozone loss during February and March reached 2.0±0.1 ppmv at 475-529 K levels.…”

Chemical ozone loss in the Arctic winter 2002/2003 determined with Match

“…4.3 Trajectory quality criteria symmetric in time Terao et al (2002) modified the original Match approach to use it with data from the Improved Limb Atmospheric Spectrometer (ILAS) for the Arctic winter 1996/1997. They introduced an additional Match radius, the backward Match radius explained earlier.…”

“…This addresses the effect of a modification of the original Match approach that was first used by Terao et al (2002).…”

A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations

“…The technique has been refined, characterized, and applied to the quantification of ozone loss in many Arctic winters (e.g., Rex et al, 1997Rex et al, , 1998Rex et al, , 1999Harris et al, 2002;Lehmann et al, 2005) and in the Antarctic (e.g., Frieler et al, 2006;Schofield et al, 2015). The approach has also been applied to observations from spaceborne solar occultation sounders (e.g., Sasano et al, 2000;Terao et al, 2002Terao et al, , 2012Hoppel et al, 2005). Similar techniques have been used in a variety of other studies, including quantification of chemical kinetics constants from observations in the polar vortex (von Hobe et al, 2007;Schofield et al, 2008;Sumińska-Ebersoldt et al, 2012); studies of PSC formation, chlorine activation and denitrification (e.g., Danilin et al, 2000;Santee et al, 2002;Rivière et al, 2003); dehydration processes occurring in the tropical tropopause layer (Inai et al, 2013); long-range transport of tropospheric pollutants (e.g., Methven et al, 2006); and validation of satellite observations (e.g., Morris et al, 2002;Danilin et al, 2002).…”