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Ozone depletion over the polar regions is monitored each year by satellite- and ground-based instruments. In this study, the vortex-averaged ozone loss over the last 3 decades is evaluated for both polar regions using the passive ozone tracer of the chemical transport model TOMCAT/SLIMCAT and total ozone observations from Système d'Analyse par Observation Zénithale (SAOZ) ground-based instruments and Multi-Sensor Reanalysis (MSR2). The passive-tracer method allows us to determine the evolution of the daily rate of column ozone destruction and the magnitude of the cumulative column loss at the end of the winter. Three metrics are used in trend analyses that aim to assess the ozone recovery rate over both polar regions: (1) the maximum ozone loss at the end of the winter, (2) the onset day of ozone loss at a specific threshold, and (3) the ozone loss residuals computed from the differences between annual ozone loss and ozone loss values regressed with respect to sunlit volume of polar stratospheric clouds (VPSCs). This latter metric is based on linear and parabolic regressions for ozone loss in the Northern Hemisphere and Southern Hemisphere, respectively. In the Antarctic, metrics 1 and 3 yield trends of - 2.3 % and - 2.2 % per decade for the 2000–2021 period, significant at 1 and 2 standard deviations (σ), respectively. For metric 2, various thresholds were considered at the total ozone loss values of 20 %, 25 %, 30 %, 35 %, and 40 %, all of them showing a time delay as a function of year in terms of when the threshold is reached. The trends are significant at the 2 σ level and vary from 3.5 to 4.2 d per decade between the various thresholds. In the Arctic, metric 1 exhibits large interannual variability, and no significant trend is detected; this result is highly influenced by the record ozone losses in 2011 and 2020. Metric 2 is not applied in the Northern Hemisphere due to the difficulty in finding a threshold value in enough of the winters. Metric 3 provides a negative trend in Arctic ozone loss residuals with respect to the sunlit VPSC fit of - 2.00 ± 0.97 (1 σ) % per decade, with limited significance at the 2 σ level. With such a metric, a potential quantitative detection of ozone recovery in the Arctic springtime lower stratosphere can be made. [ABSTRACT FROM AUTHOR]

The Human Papilloma Virus (HPV) is a virus that has a double-stranded DNA genome belonging to the Papovaviridae family. It has oncogenic ability in a variety of mammals, especially man, in which more than 200 serotypes are known and represents one of the most common sexually transmitted diseases because of its relation to oncological pathogenesis. It is classified into high and low cancer types (IARC), other types of infections such as oropharyngeal and tonsillitis have also been described. The objective of this study was to determine the screening of IgG antibodies against Human Papilloma Virus genotypes 6, 11, 16 and 18 using the Microelisa serological technique. A descriptive, prospective and cross-sectional study was carried out during the first semester of 2015 in the Gary Esparza Sector of Babahoyo, Los Ríos province, with a population of 250 habitants. Blood samples were taken from 97 women with 20 years old, being determined 8 positive cases (8.25%), establishing the first serological diagnosis in the country, which is a tool for preliminary screening or screening of a large number of samples.

Ozone depletion over the polar regions is monitored each year by satellite and ground-based instruments. In this study, the vortex-averaged ozone loss over the last three decades is evaluated for both polar regions using the passive ozone tracer of the chemical transport model TOMCAT/SLIMCAT and total ozone observations from Système d'Analyse par Observation Zénithale (SAOZ) ground-based instruments and Multi-Sensor Reanalysis (MSR2). The passive tracer method allows us to determine the evolution of the daily rate of column ozone destruction, and the magnitude of the cumulative loss the end of the winter. Three metrics are used to estimate the linear trend since 2000 and to assess the current situation of ozone recovery over both polar regions: 1) The maximum ozone loss at the end of the winter; 2) the onset day of ozone loss at specific threshold and 3) the ozone loss residuals computed from the differences between annual ozone loss and ozone loss values regressed with respect to sunlit volume of polar stratospheric clouds (VPSC). This latter metric is based on linear and parabolic regressions for ozone loss in the Northern and Southern Hemispheres, respectively. In the Antarctic, metrics 1, and yield trends of -2.3 and -1.8% dec-1 for the 2000-2021 period, significant at 1 and 2 standard error, respectively. For metric 2, various thresholds were considered, all of them showing a time delay for when they are reached. The trends are significant at the 2 level and vary from 3.5 to 4.2 day dec-1 between the various thresholds. In the Arctic, metric 1 exhibits large interannual variability and no significant trend is detected; this result is highly influenced by the record ozone losses in 2011 and 2020. Metric 2 is not applied in the Northern Hemisphere due to the difficulty of finding a threshold value in a consistent number of winters. Metric 3 shows a negative trend in Arctic ozone loss residuals of -1.7 ±1% dec-1, significant at level. This is therefore the first quantitative detection of ozone recovery in the Arctic springtime lower stratosphere. [ABSTRACT FROM AUTHOR]

After the decrease of ozone-depleting substances (ODSs) as a consequence of the Montreal Protocol, it is still challenging to detect a recovery in the total column amount of ozone (total ozone) at northern high latitudes. To assess regional total ozone changes in the "ozone-recovery" period (2000–2020) at northern high latitudes, this study investigates trends from ground-based total ozone measurements at three stations in Norway (Oslo, Andøya, and Ny-Ålesund). For this purpose, we combine measurements from Brewer spectrophotometers, ground-based UV filter radiometers (GUVs), and a SAOZ (Système d'Analyse par Observation Zénithale) instrument. The Brewer measurements have been extended to work under cloudy conditions using the global irradiance (GI) technique, which is also presented in this study. We derive trends from the combined ground-based time series with the multiple linear regression model from the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) project. We evaluate various predictors in the regression model and found that tropopause pressure and lower-stratospheric temperature contribute most to ozone variability at the three stations. We report significantly positive annual trends at Andøya (0.9±0.7 % per decade) and Ny-Ålesund (1.5±0.1 % per decade) and no significant annual trend at Oslo (0.1±0.5 % per decade) but significantly positive trends in autumn at all stations. Finally we found positive but insignificant trends of around 3 % per decade in March at all three stations, which may be an indication of Arctic springtime ozone recovery. Our results contribute to a better understanding of regional total ozone trends at northern high latitudes, which is essential to assess how Arctic ozone responds to changes in ODSs and to climate change. [ABSTRACT FROM AUTHOR]

The response of the ozone column across Europe to the extreme 2020 Arctic ozone depletion was examined by analyzing ground‐based observations at 38 European stations. The ozone decrease at the northernmost site, Ny‐Ålesund (79°N) was about 43% with respect to a climatology of more than 30 years. The magnitude of the decrease declined by about 0.7% deg−1 moving south to reach nearly 15% at 40°N. In addition, it was found that the variations of the ozone column at each of the selected stations in March‐May were similar to those observed at Ny‐Ålesund but with a delay increasing to about 20 days at mid‐latitudes with a gradient of approximately 0.5 days deg−1. The distributions of reconstructed ozone column anomalies over a sector covering a large European area show decreasing ozone that started from the north at the beginning of April 2020 and spread south. Such behavior was shown to be similar to that observed after the Arctic ozone depletion in 2011. Stratospheric dynamical patterns in March–May 2011 and during 2020 suggested that the migration of ozone‐poor air masses from polar areas to the south after the vortex breakup caused the observed ozone responses. A brief survey of the ozone mass mixing ratios at three stratospheric levels showed the exceptional strength of the 2020 episode. Despite the stronger and longer‐lasting Arctic ozone loss in 2020, the analysis in this work indicates a similar ozone response at latitudes below 50°N to both 2011 and 2020 phenomena. Plain Language Summary: The winter polar vortex isolates a huge volume of air from external impacts that, in the absence of the sunlight, leads to a great deal of cooling and the formation of polar stratospheric clouds. Chemical reactions taking place in these clouds contribute to ozone destruction. Such spring‐time ozone depletions are regularly observed in Antarctica, but usually do not occur in the Arctic where the vortex is much less intense. However, in the past three decades several similar episodes occurred in the Arctic and the most marked of them took place in the 2011 and 2020 springs. The response of the ozone layer over Europe to the 2020 episode was studied here by analyzing the data from 38 ground measurement stations. It was found that there was a nearly 43% decrease in ozone in the Arctic, and, as it spread southward, a reduction of 15% in mid‐latitudes 15–20 days later. This spread was attributed to the transport of ozone‐poor air from the Arctic to the south after the vortex breakup. Despite the stronger depletion in 2020 and some differences in the movement of air, the response of the ozone layer was quite similar in the springs of both 2011 and 2020. Key Points: The 2020 ozone depletion in the Arctic was found to impact the ozone in the mid‐latitude European areasThe magnitude of ozone decrease in the southern regions declined with respect to that in the Arctic and occurred with a delay up to 20 daysSuch a response was similar to that observed in 2011 and both were considered a result of ozone‐poor air masses transported southward [ABSTRACT FROM AUTHOR]

The objective of this paper is to estimate the trend of the Total Ozone Column (TOC) over Togo. A Multi-Sensor Reanalysis-2 (MSR-2) of the TOC over the entire territory of Togo was used. A Multiple Linear Regression (MLR) method has been applied to retrieve the interannual contributions of different forcings and the long-term variability. It was found that the Annual Oscillation (AnO), the Quasi Biennial Oscillation at 30 mb (QBO30), the Solar Flux (SF), and the El Niño–Southern Oscillation (ENSO) has a statistically significant influence on the interannual variability of the TOC. The strongest contribution (22 ± 1.4 DU) is allocated to the AnO while the weakest (<1 DU) is attributed to the Semi-Annual Oscillations (SAnO). Before the peak year of the Equivalent Effective Stratospheric Chlorine (EESC) in the tropics in 1997, the trend is negative (−0.3% ± 0.9% per decade) and is not statistically significant. After the peak year, a statistically significant positive trend is observed. The trend of the TOC is 0.6% ± 0.2% per decade. The monthly TOC trend over Togo is positive and statistically significant during the rainy season (particularly during the monsoon period) except in April, unlike during the harmattan period (DJF), where the trend is not significant. [ABSTRACT FROM AUTHOR]

The Observatoire de Haute Provence (OHP) weekly electrochemical concentration cell (ECC) ozonesonde data have been homogenized for the period 1991–2021 according to the recommendations of the Ozonesonde Data Quality Assessment (O3S-DQA) panel. The assessment of the ECC homogenization benefit has been carried out using comparisons with other ozone-measuring ground-based instruments at the same station (lidar, surface measurements) and with colocated satellite observations of the O3 vertical profile by Microwave Limb Sounder (MLS). The major differences between uncorrected and homogenized ECC data are related to a change of ozonesonde type in 1997, removal of the pressure dependency of the ECC background current and correction of internal pump temperature. The original 3–4 ppbv positive bias between ECC and lidar in the troposphere is corrected with the homogenization. The ECC 30-year trends of the seasonally adjusted ozone concentrations are also significantly improved in both the troposphere and the stratosphere after the ECC homogenization, as shown by the ECC/lidar or ECC/surface ozone trend comparisons. A -0.19 % yr -1 negative trend of the normalization factor (NT) calculated using independent measurements of the total ozone column (TOC) at OHP disappears after homogenization of the ECC data. There is, however, a remaining -3.7 % negative bias in the TOC which is likely related to an underestimate of the ECC concentrations in the stratosphere above 50 hPa. Differences between TOC measured by homogenized ECC and satellite observations show a smaller bias of -1 %. Comparisons between homogenized ECC and OHP stratospheric lidar and MLS observations below 26 km are slightly negative (-2 %) or positive (+2 %), respectively. The comparisons with both lidar and satellite observations suggest that homogenization increases the negative bias of the ECC to values lower than -6 % above 28 km. The reason for this bias is still unclear, but a possible explanation might be related to freezing or evaporation of the sonde solution in the stratosphere. [ABSTRACT FROM AUTHOR]

After the decrease of ozone-depleting substances (ODSs) as a consequence of the Montreal Protocol, it is still challenging to detect a recovery in the total column amount of ozone (total ozone) at northern high-latitudes. To assess regional total ozone changes in the "ozone-recovery"-period (2000-2020) at northern high-latitudes, this study investigates trends from ground-based total ozone measurements at three stations in Norway (Oslo, Andøya, and Ny-Ålesund). For this purpose, we combine measurements from Brewer spectrophotometers, ground-based UV filter radiometers (GUVs), and a SAOZ instrument. The Brewer measurements have been extended to work under cloudy conditions using the global irradiance (GI) technique, which is also presented in this study. We derive trends from the combined ground-based time series with the multiple linear regression model from the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) project. We evaluate various predictors in the regression model and found that tropopause pressure and lower-stratospheric temperature contribute most to ozone variability at the three stations. We report significant positive trends at Andøya (0.9% per decade) and NyÅlesund (1.5% per decade) and no annual trends at Oslo, but significant positive trends in autumn at all stations. Finally we found positive but insignificant trends of around 3% per decade in March at all three stations, which may be an indication for Arctic spring-time ozone recovery. Our results contribute to a better understanding of regional total ozone trends at northern high-latitudes, which is essential to assess how Arctic ozone responds to changes in ODSs and to climate change. [ABSTRACT FROM AUTHOR]

The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the period 1979–2020 on three isentropic levels (475, 550, and 675 K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the onset and breakup dates of the polar vortex, which are determined from wind thresholds (e.g., 15.2, 20, and 25 m s -1) along the vortex edge. The vortex edge is stronger in late winter, during September–October–November, with the period of strongest intensity occurring later at the lowermost level. During the same period, we observe a lower variability of the edge position. A long-term increase in the vortex edge intensity and break-up date is observed during 1979–1999, linked to the increase in the ozone hole. A long-term decrease in the vortex onset date related to the 25 m s -1 wind threshold is also observed at 475 K during this period. The solar cycle and to a lower extent the quasi-biennial oscillation (QBO) and El Niño–Southern Oscillation (ENSO) modulate the interannual evolution of the strength of the vortex edge and the vortex breakup dates. A stronger vortex edge and longer vortex duration are observed in solar minimum (minSC) years, with the QBO and ENSO further modulating the solar cycle influence, especially at 475 and 550 K: during west QBO (wQBO) phases, the difference between vortex edge intensity for minSC and maxSC years is smaller than during east QBO (eQBO) phases. The polar vortex edge is stronger and lasts longer for maxSC/wQBO years than for maxSC/eQBO years. ENSO has a weaker impact but the vortex edge is somewhat stronger during cold ENSO phases for both minSC and maxSC years. [ABSTRACT FROM AUTHOR]

The Observatoire de Haute Provence (OHP) weekly Electrochemical Concentration Cell (ECC) ozonesonde data have been homogenized for the time period 1991-2020 according to the recommendations of the Ozonesonde Data Quality Assessment (O3S-DQA) panel. The assessment of the ECC homogenization benefit has been carried out using comparisons with ground based instruments also measuring ozone at the same station (lidar, surface measurements) and with collocated satellite observations of the O3 vertical profile by Microwave Limb Sounder (MLS). The major differences between uncorrected and homogenized ECC are related to a change of ozonesonde type in 1997, removal of the pressure dependency of the ECC background current and correction of internal ozonesonde temperature. The 3-4 ppbv positive bias between ECC and lidar in the troposphere is corrected with the homogenization. The ECC 30-years trends of the seasonally adjusted ozone concentrations are also significantly improved both in the troposphere and the stratosphere when the ECC concentrations are homogenized, as shown by the ECC/lidar or ECC/surface ozone trend comparisons. A -0.29 % per year negative trend of the normalization factor (NT) calculated using independent measurements of the total ozone column (TOC) at OHP disappears after homogenization of the ECC. There is however a remaining -5 % negative bias in the TOC which is likely related to an underestimate of the ECC concentrations in the stratosphere above 50 hPa as shown by direct comparison with the OHP lidar and MLS. The reason for this bias is still unclear, but a possible explanation might be related to freezing or evaporation of the sonde solution in the stratosphere. Both the comparisons with lidar and satellite observations suggest that homogenization increases the negative bias of the ECC up to 10 % above 28 km. [ABSTRACT FROM AUTHOR]

The evolution of NO 2 , considered as a proxy for air pollution, was analyzed to evaluate the impact of the first lockdown (17 March–10 May 2020) over the Île-de-France region (Paris and surroundings). Tropospheric NO 2 columns measured by two UV-Visible Système d'Analyse par Observation Zénithale (SAOZ) spectrometers were analyzed to compare the evolution of NO 2 between urban and suburban sites during the lockdown. The urban site is the observation platform QualAir (48 ∘ 50 ′ N / 2 ∘ 21 ′ E) at the Sorbonne University Pierre and Marie Curie Campus in the center of Paris. The suburban site is located at Guyancourt (48 ∘ 46 ′ N / 2 ∘ 03 ′ E), Versailles Saint-Quentin-en-Yvelines University, 24 km southwest of Paris. Tropospheric NO 2 columns above Paris and Guyancourt have shown similar values during the whole lockdown period from March to May 2020. A decade of data sets were filtered to consider air masses at both sites with similar meteorological conditions. The median NO 2 columns and the surface measurements of Airparif (Air Quality Observatory in Île de France) during the lockdown period in 2020 were compared to the extrapolated values estimated from a linear trend analysis for the 2011–2019 period at each station. Negative NO 2 trends of - 1.5 Pmolec. cm -2 yr -1 (∼ - 6.3 % yr -1) are observed from the columns, and trends of -2.2 µg m -3 yr -1 (∼ - 3.6 % yr -1) are observed from the surface concentration. The negative anomaly in tropospheric columns in 2020 attributed to the lockdown (and related emission reductions) was found to be 56 % at Paris and 46 % at Guyancourt, respectively. A similar anomaly was found in the data of surface concentrations, amounting to 53 % and 28 % at the urban and suburban sites, accordingly. [ABSTRACT FROM AUTHOR]

The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the 1979 - 2020 period on three isentropic levels (475K, 550K and 675K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the onset and breakup dates of the polar vortex, which are determined from wind thresholds (e.g. 15.2 m.s-1, 20 m.s-1 and 25 m.s-1) along the vortex edge. The vortex edge is stronger in late winter, over September - October - November with the period of strongest intensity occurring later at the lowermost level. A lower 5 variability of the edge position is observed during the same period. Long-term increase of the vortex edge intensity and breakup date is observed over the 1979 - 1999 period, linked to the increase of the ozone hole. Long-term decrease of the vortex onset date related to the 25 m.s-1 wind threshold is also observed at 475K during this period. The solar cycle and to a lower extent the quasi-biennal oscillation (QBO) and El Niño Southern Oscillation (ENSO) modulate the inter-annual evolution of the strength of the vortex edge and the vortex breakup dates. Stronger vortex edge and longer vortex duration is observed in 10 solar minimum (minSC) years, with the QBO and ENSO further modulating the solar cycle influence, especially at 475K and 550K: during West QBO (wQBO) phases, the difference between vortex edge intensity for minSC and maxSC years is smaller than during East QBO (eQBO) phases. The polar vortex edge is stronger and lasts longer for maxSC/wQBO years than for maxSC/eQBO years. ENSO has a weaker impact but the vortex edge is somewhat stronger during cold ENSO phases for both minSC and maxSC years. [ABSTRACT FROM AUTHOR]

The evolution of NO2, considered as proxy for air pollution, was analyzed to evaluate the impact of 1st lockdown (March 17th - May 10th 2020) over île-de-France region (Paris and surroundings). Tropospheric NO2 columns measured by two UV-Visible SAOZ spectrometers were analyzed to compare the evolution of NO2 between urban and suburban sites during the lockdown. The urban site is the observation platform QUALAIR (48°50' N/2°21' E) on the Pierre et Marie Curie Campus of Sorbonne University in the center of Paris. The suburban site is located at Guyancourt (48°46' N/2°03' E), University of Versailles Saint Quentin, 24 km south-west of Paris. Tropospheric NO2 columns above Paris and Guyancourt have shown similar values during the whole lockdown period from March to May 2020. One decade datasets were filtered to consider air masses at both sites with similar meteorological conditions. The median NO2 columns, as well as the surface measurements of AIPARIF (Air Quality Observatory in Ile de France) during the lockdown period in 2020 were compared to the extrapolated values estimated from a linear trend analysis for the 2011-2019 period at each station. Negative NO2 trends of -1.5 Pmolec cm-2 yr-1 (~-6.3 % yr-1) are observed from the columns and of -2.2 μg m-3 yr-1 (~-3.6 % yr-1) from the surface concentration. The negative anomaly in tropospheric columns in 2020 attributed to lockdown (and related emission reductions) was found to be 56 % at Paris and 46 % at Guyancourt, respectively. Similar anomaly was found in the data of surface concentrations, amounting for 53 % and 28 % at the urban and suburban sites, accordingly. [ABSTRACT FROM AUTHOR]

This paper reports on consolidated ground-based validation results of the atmospheric NO2 data produced operationally since April 2018 by the TROPOMI instrument on board of the ESA/EU Copernicus Sentinel-5 Precursor (S5p) satellite. Tropospheric, stratospheric, and total NO2 column data from S5p are compared to correlative measurements collected from, respectively, 19 Multi-Axis DOAS (MAX-DOAS), 26 NDACC Zenith-Scattered-Light DOAS (ZSL-DOAS), and 25 PGN/Pandora instruments distributed globally. The validation methodology gives special care to minimizing mismatch errors due to imperfect spatio-temporal co-location of the satellite and correlative data, e.g., by using tailored observation operators to account for differences in smoothing and in sampling of atmospheric structures and variability, and photochemical modelling to reduce diurnal cycle effects. Compared to the ground-based measurements, S5p data show, on an average: (i) a negative bias for the tropospheric column data, of typically -23 to -37% in clean to slightly polluted conditions, but reaching values as high as -51% over highly polluted areas; (ii) a slight negative bias for the stratospheric column data, of about -0.2Pmolec/cm2, i.e. approx. -2% in summer to -15% in winter; and (iii) a bias ranging from zero to -50% for the total column data, found to depend on the amplitude of the total NO2 column, with small to slightly positive bias values for columns below 6Pmolec/cm2 and negative values above. The dispersion between S5p and correlative measurements contains mostly random components, which remain within mission requirements for the stratospheric column data (0.5Pmolec/cm2), but exceed those for the tropospheric column data (0.7Pmolec/cm2). While a part of the biases and dispersion may be due to representativeness differences, it is known that errors in the S5p tropospheric columns exist due to shortcomings in the (horizontally coarse) a-priori profile representation in the TM5-MP chemistry transport model used in the S5p retrieval, and to a lesser extent, to the treatment of cloud effects. Although considerable differences (up to 2Pmolec/cm2 and more) are observed at single ground-pixel level, the near-real-time (NRTI) and off-line (OFFL) versions of the S5p NO2 operational data processor provide similar NO2 column values and validation results when globally averaged, with the NRTI values being on average 0.79% larger than the OFFL values. [ABSTRACT FROM AUTHOR]

A broad ligament can drive it in 5% of cases. Bowel obstruction through a defect in the broad ligament of the uterus is an uncommon disease. We present a 41‐year‐old woman who underwent an abdominal laparoscopic. It showed diffuse loop dilation, minimal free fluid in the pelvis, and an unexpected small orifice in the right broad ligament of the uterus, which measured approximately 3 cm. [ABSTRACT FROM AUTHOR]

Subpolar regions in the Southern Hemisphere are influenced by the Antarctic polar vortex during austral spring, which induces high and short-term ozone variability at different altitudes, mainly into the stratosphere. This variation may affect considerably the total ozone column changing the harmful UV radiation that reaches the surface. With the aim of studying ozone with a high time resolution at different altitudes in subpolar regions, a millimetre-wave radiometer (MWR) was installed at the Observatorio Atmosférico de la Patagonia Austral (OAPA), Río Gallegos, Argentina (51.6 ∘ S, 69.3 ∘ W), in 2011. This instrument provides ozone profiles with a time resolution of ∼1 h, which enables studies of short-term ozone mixing ratio variability from 25 to ∼70 km in altitude. This work presents the MWR ozone observations between October 2014 and 2015, focusing on an atypical event of the polar vortex and Antarctic ozone hole influence over Río Gallegos detected from the MWR measurements at 27 and 37 km during November of 2014. During the event, the MWR observations at both altitudes show a decrease in ozone followed by a local peak of ozone amount of the order of hours. This local recovery is observed thanks to the high time resolution of the MWR mentioned. The advected potential vorticity (APV) calculated from the MIMOSA high-resolution advection model (Modélisation Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection) was also analysed at two isentropic levels (levels of constant potential temperature) of 675 and 950 K (∼27 and ∼37 km of altitude, respectively) to understand and explain the dynamics at both altitudes and correlate the ozone rapid recovery with the passage of a tongue with low PV values over Río Gallegos. In addition, the MWR dataset was compared for the first time with measurements obtained from the Microwave Limb Sounder (MLS) at individual altitude levels (27, 37 and 65 km) and with the differential absorption lidar (DIAL) installed in the OAPA to analyse the correspondence between the MWR and independent instruments. The MWR–MLS comparison presents a reasonable correlation with mean bias errors of + 5 %, - 11 % and - 7 % at 27, 37 and 65 km, respectively. The MWR–DIAL comparison at 27 km also presents good agreement, with a mean bias error of - 1 %. [ABSTRACT FROM AUTHOR]

The long-term evolution of total ozone column inside the Antarctic polar vortex is investigated over the 1980-2017 period. Trend analyses are performed using a multilinear regression (MLR) model based on various proxies for the evaluation of ozone interannual variability (heat flux, quasi-biennial oscillation, solar flux, Antarctic oscillation and aerosols). Annual total ozone column measurements corresponding to the mean monthly values inside the vortex in September and during the period of maximum ozone depletion from 15 September to 15 October are used. Total ozone columns from the Multi-Sensor Reanalysis version 2 (MSR-2) dataset and from a combined record based on TOMS and OMI satellite datasets with gaps filled by MSR-2 (1993-1995) are considered in the study. Ozone trends are computed by a piece-wise trend (PWT) proxy that includes two linear functions before and after the turnaround year in 2001 and a parabolic function to account for the saturation of the polar ozone destruction. In order to evaluate average total ozone within the vortex, two classification methods are used, based on the potential vorticity gradient as a function of equivalent latitude. The first standard one considers this gradient at a single isentropic level (475 or 550 K), while the second one uses a range of isentropic levels between 400 and 600 K. The regression model includes a new proxy (GRAD) linked to the gradient of potential vorticity as a function of equivalent latitude and representing the stability of the vortex during the studied month. The determination coefficient (R²) between observations and modelled values increases by *** 0.05 when this proxy is included in the MLR model. Highest R² (0.92-0.95) and minimum residuals are obtained for the second classification method for both datasets and months. Trends in September over the 2001-2017 period are statistically significant at 2σ level with values ranging between 1.84±1.03 and 2.83±1.48 DU yr-1 depending on the methods and considered proxies. This result confirms the recent studies of Antarctic ozone healing during that month. Trends from 2001 are 2 to 3 times smaller than before the turnaround year, as expected from the response to the slowly ozonedepleting substances decrease in polar regions. For the first time, significant trends are found for the period of maximum ozone depletion. Estimated trends from 2001 for the 15 September-15 October period over 2001± 2017 vary from 1.21±0.83 to 1.96DU±0.99 yr-1 and are significant at 2σ level. MLR analysis is also applied to the ozone mass deficit (OMD) metric for both periods, considering a threshold at 220DU and total ozone columns south of 60° S. Significant trend values are observed for all cases and periods. A decrease of OMD of 0.86±0.36 and 0.65±0.33 Mt yr-1 since 2001 is observed in September and 15 September-15 October, respectively. Ozone recovery is also confirmed by a steady decrease of the relative area of total ozone values lower than 175DU within the vortex in the 15 September-15 October period since 2010 and a delay in the occurrence of ozone levels below 125DU since 2005. [ABSTRACT FROM AUTHOR]

Ultraviolet radiation (UVR) exposure, skin cancer and other related diseases are not just subjects of scientific literature. Nowadays, these themes are also discussed on television, newspapers and magazines for the general public. Consequently, the interest in prevention of sun overexposure is increasing, as the knowledge of photoprotection methods and UVR levels. The ultraviolet index (UVI) is a well-known tool recommended by the World Health Organization to avoid harmful effects of UV sunlight. UVI forecasts are provided by many national meteorological services, but local UVI measurements can provide a more realistic and appropriate evaluation of UVR levels. Indeed, as scientific instruments are very expensive and difficult to manipulate, several manufacturers and retail shops offer cheap and simple non-scientific instruments for UVI measurements, sometimes included in objects of everyday life, such as watches, outfits and hand-held instruments. In this work, we compare measurements provided by several commercial non-scientific instruments with data provided by a Bentham spectrometer, a very accurate sensor used for UV measurements. Results show that only a few of the instruments analyzed provide trustworthy UVI measurements.