Observed and simulated time evolution of HCl, ClONO2, and HF total column abundances

Time series of total column abundances of hydrogen chloride (HCl), chlorine nitrate (ClONO2), and hydrogen fluoride (HF) were determined from ground-based Fourier transform infrared (FTIR) spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC) and located between 80.05°N and 77.82°S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl and ClONO2, the present study is able to confirm the decrease of the atmospheric inorganic chlorine abundance during the last few years. This decrease is expected following the 1987 Montreal Protocol and its amendments and adjustments, where restrictions and a subsequent phase-out of the prominent anthropogenic chlorine source gases (solvents, chlorofluorocarbons) were agreed upon to enable a stabilisation and recovery of the stratospheric ozone layer. The atmospheric fluorine content is expected to be influenced by the Montreal Protocol, too, because most of the banned anthropogenic gases also represent important fluorine sources. But many of the substitutes to the banned gases also contain fluorine so that the HF total column abundance is expected to have continued to increase during the last few years. The measurements are compared with calculations from five different models: the two-dimensional Bremen model, the two chemistry-transport models KASIMA and SLIMCAT, and the two chemistry-climate models EMAC and SOCOL. Thereby, the ability of the models to reproduce the absolute total column amounts, the seasonal cycles, and the temporal evolution found in the FTIR measurements is investigated and inter-compared. This is especially interesting because the models have different architectures. The overall agreement between the measurements and models for the total column abundances and the seasonal cycles is good. Linear trends of HCl, ClONO2, and HF are calculated from both measurement and model time series data, with a focus on the time range 2000–2009. This period is chosen because from most of the measurement sites taking part in this study, data are available during these years. The precision of the trends is estimated with the bootstrap resampling method. The sensitivity of the trend results with respect to the fitting function, the time of year chosen and time series length is investigated, as well as a bias due to the irregular sampling of the measurements. The measurements and model results investigated here agree qualitatively on a decrease of the chlorine species by around 1%yr-1. The models simulate an increase of HF of around 1%yr-1. This also agrees well with most of the measurements, but some of the FTIR series in the Northern Hemisphere show a stabilisation or even a decrease in the last few years. In general, for all three gases, the measured trends vary more strongly with latitude and hemisphere than the modelled trends. Relative to the FTIR measurements, the models tend to underestimate the decreasing chlorine trends and to overestimate the fluorine increase in the Northern Hemisphere. At most sites, the models simulate a stronger decrease of ClONO2 than of HCl. In the FTIR measurements, this difference between the trends of HCl and ClONO2 depends strongly on latitude, especially in the Northern Hemisphere.Peer reviewe

Validation of MIPAS CH₄ profiles by stratospheric balloon, aircraft and ground based measurements.

International audienceThe ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS included a number of balloon-borne, aircraft, other satellite and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. In parallel to the contribution of the individual validation teams, the present paper provides a synthesis of comparisons made between MIPAS CH 4 profiles produced by the current ESA operational software (Instrument Processing Facility version 4.61 i.e. IPF v4.61) or by the IMK-FZK scientific processor and correlative measurements obtained from balloon and aircraft experiments as well as from satellite sensors or from ground-based instruments

Validation of MIPAS N₂O profiles by stratospheric balloon, aircraft and ground based measurements

The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-bone, aircraft and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. As a companion to a similar paper on CH4 and in parallel to the contribution of the individual validation teams, the present paper provides a synthesis of comparisons performed between MIPAS N2O profiles produced by the current ESA operational software (Instrument Processing Facility version 4.61 or IPF v4.61) or by the IMK-FZK scientific processor and correlative measurements obtained from balloon and aircraft experiments as well as from ground-based instruments

Santé publique et culture familiale de la santé mentale

Contexte théorique En Suisse, comme dans la plupart des pays industrialisés, on estime que 20% des adolescents souffre de problèmes psychiques et un grand nombre d’entre eux ne bénéficient pas de traitement. De plus, la plupart des recherches longitudinales sont en accord pour affirmer que les problèmes psychiques graves qui surgissent pendant l’enfance ou l’adolescence et qui ne sont pas traites, ou qui le sont trop tardivement, peuvent avoir des conséquences lourdes sur le développement de la personne ainsi que sur sa famille. Objectifs de l’étude Les objectifs de la thèse sont d’explorer les concepts de sante et maladie psychique, les stratégies d’action face à un problème de sante psychique et finalement les barrières qui empêchent l’accès au système de sante mentale pour les adolescents. Je voudrais examiner ces différents aspects chez les adolescents et leur famille, en regardant s’ils existent des différences culturelles en Suisse, des différences de sexe, d’âge et d’expérience de traitement avec le système sanitaire en matière de sante mentale. Tout ces éléments permettent une description de la culture familiale de la sante mentale. Cette description ainsi que la compréhension d’une culture familiale de la sante mentale dans les familles suisses est un élément indispensable pour la détection des barrières qui se trouvent a l’intérieur de la famille et qui empêchent l’accès au système de sante mentale pour les adolescents. Méthodologie Une méthodologie mixte, qualitative et quantitative, est à la base de cette these. Des entretiens (N=101) avec des adolescents (10-16 ans) de la population générale, à risque et clinique, et leurs parents composent la partie qualitative. Cet outil permettra de collecter et d'analyser les concepts relatifs a la sante et a la maladie ainsi que les stratégies selon lesquelles les adolescents et leurs familles ont recours aux soins de sante mentale. Sur la base des résultats de l’analyse qualitative, effectuée a l’aide du logiciel MAXqda et intégrée dans le modèle socio écologique de Bronfenbrenner, nous avons élaboré le questionnaire, instrument de la phase quantitative, pour réaliser l’enquête en Suisse alémanique, Suisse romande et au Tessin (N=819). Résultats Les résultats montrent des différences dans la perception de la sante mentale entre les régions linguistiques suisses et les générations. L’expérience de traitement dans le système des soins et le sexe, ont des répercussions sur le choix des stratégies d’action face à un problème de sante mentale. La perception de la culture familiale de la sante mentale est également différente entre les régions culturelles. Les barrières vers l’accès au système des soins sont présentes au niveau individuel, familial et social. Conclusion Tenir compte des différences générationnelles et régionales, ainsi que du point de vue des adolescents est, a notre avis, un outil important pour améliorer l’accès au système des soins en sante mentale des adolescents et la qualité de la communication entre le médecin et la famille. La culture familiale de la sante mentale se révèle être un élément important en sante publique

The canary in the city: indicator groups as predictors of local rent increases

Abstract As cities grow, certain neighborhoods experience a particularly high demand for housing, resulting in escalating rents. Despite far-reaching socioeconomic consequences, it remains difficult to predict when and where urban neighborhoods will face such changes. To tackle this challenge, we adapt the concept of ‘bioindicators’, borrowed from ecology, to the urban context. The objective is to use an ‘indicator group’ of people to assess the quality of a complex environment and its changes over time. Specifically, we analyze 92 million geolocated Twitter records across five US cities, allowing us to derive socio-economic user profiles based on individual movement patterns. As a proof-of-concept, we define users with a ‘high-income-profile’ as an indicator group and show that their visitation patterns are a suitable indicator for expected future rent increases in different neighborhoods. The concept of indicator groups highlights the potential of closely monitoring only a specific subset of the population, rather than the population as a whole. If the indicator group is defined appropriately for the phenomenon of interest, this approach can yield early predictions while simultaneously reducing the amount of data that needs to be collected and analyzed

Validation of MIPAS ClONO₂ measurements

International audienceAltitude profiles of ClONO2 retrieved with the IMK (Institut für Meteorologie und Klimaforschung) science-oriented data processor from MIPAS/Envisat (Michelson Interferometer for Passive Atmospheric Sounding on Envisat) mid-infrared limb emission measurements between July 2002 and March 2004 have been validated by comparison with balloon-borne (Mark IV, FIRS2, MIPAS-B), airborne (MIPAS-STR), ground-based (Spitsbergen, Thule, Kiruna, Harestua, Jungfraujoch, Izaña, Wollongong, Lauder), and spaceborne (ACE-FTS) observations. With few exceptions we found very good agreement between these instruments and MIPAS with no evidence for any bias in most cases and altitude regions. For balloon-borne measurements typical absolute mean differences are below 0.05 ppbv over the whole altitude range from 10 to 39 km. In case of ACE-FTS observations mean differences are below 0.03 ppbv for observations below 26 km. Above this altitude the comparison with ACE-FTS is affected by the photochemically induced diurnal variation of ClONO2. Correction for this by use of a chemical transport model led to an overcompensation of the photochemical effect by up to 0.1 ppbv at altitudes of 30?35 km in case of MIPAS-ACE-FTS comparisons while for the balloon-borne observations no such inconsistency has been detected. The comparison of MIPAS derived total column amounts with ground-based observations revealed no significant bias in the MIPAS data. Mean differences between MIPAS and FTIR column abundances are 0.11±0.12×1014 cm?2 (1.0±1.1%) and ?0.09±0.19×1014 cm?2 (?0.8±1.7%), depending on the coincidence criterion applied. ?2 tests have been performed to assess the combined precision estimates of MIPAS and the related instruments. When no exact coincidences were available as in case of MIPAS ? FTIR or MIPAS ? ACE-FTS comparisons it has been necessary to take into consideration a coincidence error term to account for ?2 deviations. From the resulting ?2 profiles there is no evidence for a systematic over/underestimation of the MIPAS random error analysis