Linking uncertainty in simulated Arctic ozone loss to uncertainties in modelled tropical stratospheric water vapour

Stratospheric water vapour influences the chemical ozone loss in the polar stratosphere via control of the polar stratospheric cloud formation. The amount of water vapour entering the stratosphere through the tropical tropopause differs substantially between simulations from chemistry–climate models (CCMs). This is because the present-day models, e.g. CCMs, have difficulties in capturing the whole complexity of processes that control the water transport across the tropopause. As a result there are large differences in the stratospheric water vapour between the models.In this study we investigate the sensitivity of simulated Arctic ozone loss to the simulated amount of water vapour that enters the stratosphere through the tropical tropopause. We used a chemical transport model, FinROSE-CTM, forced by ERA-Interim meteorology. The water vapour concentration in the tropical tropopause was varied between 0.5 and 1.6 times the concentration in ERA-Interim, which is similar to the range seen in chemistry–climate models. The water vapour changes in the tropical tropopause led to about 1.5&thinsp;ppmv less and 2&thinsp;ppmv more water vapour in the Arctic polar vortex compared to the ERA-Interim, respectively. The change induced in the water vapour concentration in the tropical tropopause region was seen as a nearly one-to-one change in the Arctic polar vortex.We found that the impact of water vapour changes on ozone loss in the Arctic polar vortex depends on the meteorological conditions. The strongest effect was in intermediately cold stratospheric winters, such as the winter of 2013/2014, when added water vapour resulted in 2&thinsp;%–7&thinsp;% more ozone loss due to the additional formation of polar stratospheric clouds (PSCs) and associated chlorine activation on their surface, leading to ozone loss. The effect was less pronounced in cold winters such as the 2010/2011 winter because cold conditions persisted long enough for a nearly complete chlorine activation, even in simulations with prescribed stratospheric water vapour amount corresponding to the observed values. In this case addition of water vapour to the stratosphere led to increased areas of ICE PSCs but it did not increase the chlorine activation and ozone destruction significantly. In the warm winter of 2012/2013 the impact of water vapour concentration on ozone loss was small because the ozone loss was mainly NOx-induced. The results show that the simulated water vapour concentration in the tropical tropopause has a significant impact on the Arctic ozone loss and therefore needs to be well simulated in order to improve future projections of the recovery of the ozone layer.</p

A chemistry-transport model simulation of middle atmospheric ozone from 1980 to 2019 using coupled chemistry GCM winds and temperatures

International audienceA Global 40-year simulation from 1980 to 2019 was performed with the FinROSE chemistry-transport model based on the use of coupled chemistry GCM-data. The main focus of our analysis is on climatological-scale processes in high latitudes. The resulting trend estimates for the past period (1980?1999) agree well with observation-based trend estimates. The results for the future period (2000?2019) suggest that the extent of seasonal ozone depletion over both northern and southern high-latitudes has likely reached its maximum. Furthermore, while climate change is expected to cool the stratosphere, this cooling is unlikely to accelerate significantly high latitude ozone depletion. However, the recovery of seasonal high latitude ozone losses will not take place during the next 15 years

UV measurements at Marambio and Ushuaia during 2000–2010

Solar ultraviolet (UV) irradiances were measured with NILU-UV multichannel radiometers at Ushuaia (54°&thinsp;S) and Marambio (64°&thinsp;S) between 2000 and 2013. The measurements were part of the Antarctic NILU-UV network, which was started in cooperation between Spain, Argentina and Finland. The erythemally weighted UV irradiance time series of both stations were analysed for the first time. The quality assurance procedures included a travelling reference instrument to transfer the irradiance scale to the stations. The time series were homogenized and high quality measurements were available for the period 2000–2010. During this period UV indices of 11 or more were measured on 5 and 35 days at Marambio and Ushuaia, respectively. At Marambio, the peak daily maximum UV index of 12 and daily doses of around 7&thinsp;kJ&thinsp;m−2 were measured in November 2007. The highest UV daily doses at both stations were typically around 6&thinsp;kJ&thinsp;m−2 and occurred when the stations were inside the polar vortex, resulting in very low total ozone amount. At both stations, daily doses in late November could even exceed those in the summer. At Marambio, in some years, also daily doses in October can be as high as those during the summer. At Ushuaia, the peak daily maximum UV index of 13 was measured twice: in November 2003 and 2009. Also during those days, the station of Ushuaia was inside the polar vortex.</p

Analysis of ozone distribution in the Antarctic vortex collar region

Ozone sounding profiles will be used to analyse the ozone distribution in the Antarctic vortex collar region. The collar region will be defined based on the gradient in the potential vorticity field calculated from ECMWF ERA-Interim reanalysis data. The sounding profiles will be classified into vortex collar and in-vortex cases. Additionally the data will be divided according to equivalent latitude. Ozone soundings have been made in Marambio (64S, 57W), on the Antarctic Peninsula, since 1988, i.e. soon after the discovery of the Antarctic 'ozone hole'. The ozone sounding record at Marambio now covers more than two decades of nearly continuous ozone profile data. The vortex edge is often located close to Marambio. Data from other Antarctic sounding stations and Earth observation data will be used to increase the number of observations from the collar area. The analysis will be supported by data from the FinROSE chemistry-transport model, which will be driven by the ERA-Interim winds and temperatures

Mesosphere-to-stratosphere descent of odd nitrogen in February–March 2009 after sudden stratospheric warming

Rajčica je zeljasta jednogodišnja biljka. Sastoji se od 93 do 95 % vode, 5 do 7 % suhe tvari, organskih kiselina (limunske i jabučne), šećera (glukoze, fruktoze i saharoze), tvari netopljivih u alkoholu (proteini, celuloza, pektin, polisaharidi), karotenoida i lipida. Cilj ovog rada bio je testiranje učinkovitosti primjene mikrokapsula na bazi alginata sa simultano inkapsuliranim ionima bakra (Cu2+) ili kalcija (Ca2+) i spora gljive Trichoderma viride, na prinos i kvalitetu rajčice uzgojene u tlu u zaštićenom negrijanom plasteniku. Tijekom višekratne berbe utvrđen je broj tržnih i netržnih plodova, masa tržnih i netržnih plodova, prinos i kvalitativna svojstva. Kemijskom analizom utvrđen je udio karotenoida, ukupnih polifenola te antioksidacijska aktivnost plodova. Rezultati su pokazali pozitivan utjecaj mikrokapsula na rajčicu. Izdvojiti posebno neki tretman kod rajčice je teško jer uz genetiku svake sorte rajčice, svaki tretman je pokazao svoj rezultat. Tretman mikrokapsula s Cu2+ je u prosjeku davao najbolje rezultate u smislu morfoloških karakteristika. Tretmani mikrokapsula s kalcijevim ionima imali su pozitivan utjecaj na sadržaj likopena.Tomato is a herbaceous one-year plant. It consists of 93-95% water, 5-7% dry matter, organic acids (lemon and apple), sugars (glucose, fructose and sucrose), alcohol-insoluble substances (proteins, cellulose, pectin, polysaccharides), carotenoids and lipids. The aim of this paper was to test the efficacy of microcapsules based on biopolymer alginate with simultaneously encapsulated copper (Cu2 +) or calcium (Ca2 +) and Trichoderma viride fungus spores on the yield and quality of tomatoes grown in soil in protected nonheated greenhouses. During the multiple harvests, the number of marketable and non-marketable fruits, the mass of marketable and non-marketable fruits, yield and qualitative properties was established. Chemical analysis showed the proportion of carotenoids, total polyphenols, and antioxidant activity of fruits. The results showed a positive influence on the tomatoes treated with microcapsules. To distinguish a particular tomato treatment is difficult because, with the genetics of each tomato variety, each treatment showed relatively different results. Treatment with microcapsules with Cu2 + gave the best results in terms of morphological characteristics. Microcapsules loaded with Ca2+ had a positive effect on lycopene content