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- ItemLong-term wintertime trend of zonally asymmetric ozone in boreal extratropics during 1979-2016(Basel : MDPI AG, 2018) Schneidereit, A.; Peters, D.H.W.Strong zonally asymmetric ozone (ZAO) changes are observed in the boreal extratropics for winter. During the TOMS (Total Ozone Mapping Spectrometer) period (1979-1992) the decrease of zonally asymmetric total ozone (ZATO) was twice as large as the observed zonal mean total ozone trend over Europe in January mainly caused by ultra-long wave transport. Recent studies have demonstrated that the ozone evolution reveals three different quasi-bidecadal trend stages: (i) Decline, (ii) leveling, and (ii) healing. This study focuses on the ZAO structure in boreal extratropics and on ozone transport changes by ultra-long waves during winter months. ERA-Interim data together with a linearized transport model are used. During the healing stage ZATO increases significantly over the North Atlantic/European region for January. The ZATO increase (healing stage) and ZATO decrease (decline stage) are caused by different monthly mean ozone transport characteristics of ultra-long planetary waves over the North Atlantic/European region. Furthermore, the vertical advection (ageostrophic transport) of ozone versus its horizontal component dominates in the lower and middle stratosphere during the healing stage. It is hypothesized that these ageostrophic wind changes are mainly caused by a wave train directed northeastwards which seems to be directly linked to the Arctic warming. © 2018 by the authors.
- ItemThe revised method for retrieving daytime distributions of atomic oxygen and odd-hydrogens in the mesopause region from satellite observations(Heidelberg : Springer, 2022) Kulikov, Mikhail Y.; Belikovich, Mikhail V.; Grygalashvyly, Mykhaylo; Sonnemann, Gerd R.; Feigin, Alexander M.Atomic oxygen (O) and atomic hydrogen (H) in the mesopause region are critical species, governing chemistry, airglow, and energy budget. However, they cannot be directly measured by satellite remote sensing techniques and so inference techniques, by airglow observations, are used. In this work, we retrieved daytime O and H distributions at ~ 77 km–100 km from the data of observations by the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument at the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite in 2003–2015. The retrieval approach considered the reaction H + O3 → O2 + OH in the ozone balance equation. Moreover, we revised all quenching and spontaneous emission coefficients according to latest published data. We then calculated daytime distributions of OH and HO2 at these altitudes with the use of their conditions of photochemical equilibrium.
- ItemShort term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries(London : BMJ Publ. Group, 2020) Vicedo-Cabrera, Ana M.; Sera, Francesco; Liu, Cong; Armstrong, Ben; Milojevic, Ai; Guo, Yuming; Tong, Shilu; Lavigne, Eric; Kyselý, Jan; Urban, Aleš; Orru, Hans; Indermitte, Ene; Pascal, Mathilde; Huber, Veronika; Schneider, Alexandra; Katsouyanni, Klea; Samoli, Evangelia; Stafoggia, Massimo; Scortichini, Matteo; Hashizume, Masahiro; Honda, Yasushi; Ng, Chris Fook Sheng; Hurtado-Diaz, Magali; Cruz, Julio; Silva, Susana; Madureira, Joana; Scovronick, Noah; Garland, Rebecca M.; Kim, Ho; Tobias, Aurelio; Íñiguez, Carmen; Forsberg, Bertil; Åström, Christofer; Ragettli, Martina S.; Röösli, Martin; Guo, Yue-Liang Leon; Chen, Bing-Yu; Zanobetti, Antonella; Schwartz, Joel; Bell, Michelle L.; Kan, Haidong; Gasparrini, AntonioObjective To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide. Design Two stage time series analysis. Setting 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network. Population Deaths for all causes or for external causes only registered in each city within the study period. Main outcome measures Daily total mortality (all or non-external causes only). Results A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 μg/m 3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 μg/m 3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 μg/m 3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively. Conclusions Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies. © Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to.