Statistical estimations of the number of future ozone exceedances due to climate change in Europe

A statistical model to examine the potential impact of increasing future temperatures due to climate change on ozone exceedances (days with daily maximum 8 h average ≥ 60 ppb) is developed for Europe. We employ gridded observed daily maximum temperatures and hourly ozone observations from nonurban stations across Europe, together with daily maximum temperatures for 2021–2050 and 2071–2100 from three regional climate models, based on the Intergovernmental Panel on Climate Change Special Reports on Emissions Scenarios A1B scenario. A rotated principal components analysis is applied to the ozone stations yielding five principal components, which divide the study domain in five subregions. The historical ozone-temperature relationship is examined and then used to provide estimates of future ozone exceedance days under current emissions and under the assumption that this relationship will retain its main characteristics. Results suggest that increases in the upper temperature percentiles lead to statistically significant increases (95% statistical significance level) of the ozone exceedances for both future periods. The greatest average increases depending on the particular regional climate model range from 5 to 12 extra ozone days/yr for 2021–2050 and from 16 to 25 for 2071–2100, in southeast Europe. The lowest average increases range from 0 to 2 extra ozone days/yr for 2021–2050 and from 2 to 4 for 2071–2100 and are seen in northwest Europe. The simulations with the dynamical Goddard Institute of Space Studies/GEOS-CHEM climate chemistry modeling system shows decreases instead of increases in eastern Europe, higher increases in northwest Europe, whereas for the other subregions similar results to the statistical model are obtained

Estimating future air-quality due to climate change: the Athens case study

The aim of this study is to investigate the development of an empirical-statistical model in order to examine the potential impact of increasing future temperatures on ozone exceedance days in the Greater Athens Area. It is based on the concept that temperature is a capable predictor for the ozone concentrations and that in a future climate change world, the likelihood of ozone pollution episodes may increase

Assessment of the Impacts of Climate Change on European Ozone Levels

The objective of this study is to investigate the potential impact of future climate change on ozone air quality in Europe. To provide a full assessment, simulations with the global chemical transport model GEOS-CHEM driven by the NASA Goddard Institute for Space Studies general circulation model (NASA/GISS GCM) are conducted. To isolate the effects from changes in climate and anthropogenic emissions four types of simulations are performed: (1) present-day climate and emissions (2) future climate following the IPCC Special Report on Emission Scenarios (SRES) A1B scenario and present-day anthropogenic emissions of ozone precursors (3) present-day climate and future emissions and (4) future climate and future emissions. Results indicate that climate change impact on its own leads to an increase of less than 3 ppb in western and central Europe whereas decreases are evident for the rest of the areas with the highest (about 2.5 ppb) in southeastern Europe (Italy, Greece). Increases are attributed to the increases of isoprene biogenic emissions due to increasing temperatures whereas decreases are associated with the increase of water vapor over sea which tends to decrease the lifetime of ozone as well as the increased wind speeds in the 2050 climate. When future emissions are implemented in the future climate simulations, the greatest increases are seen in the southwest and southeast Mediterranean (about 16 ppb) due to the increased isoprene biogenic emissions under higher levels of NOx in the model. Decreases up to 2 ppb of ozone are shown for France, Switzerland, Northern Italy and northern Europe

Climate change and future ozone concentrations in high resolution over Europe

In this study a methodology is developed that applies the ozone concentration change signal from a global climate-chemical modeling system with a coarse horizontal resolution to a finer resolution. To this aim simulations with two different configurations of the GEOS-CHEM chemical transport model are conducted a) driven from the GISS III general circulation model (4ox 5o) for a present (1999–2001) and a future (2049–2051) period and b) driven by assimilated meteorological data (GEOS, 0.5o x 0.667o) for the year 2005. Results indicate highest increases between the future and the reference period in the north west and the south west Europe for both the average mean (~ 5 ppb) and average daily maximum ozone concentrations (~ 10 ppb) whereas the highest decreases (~ 4-6 ppb) are shown in the south East Europe for the same statistical targets. Moreover, these results are of the same sign to the results of the global climate-chemical modelling system in the North-west and the South-east Europe. Nevertheless changes in the GISS/GEOS-CHEM between the future and the present climate are in the range of ± 2 ppb and ± 3 ppb for the average mean and the average daily maximum ozone concentrations respectively

Self-other agreement for improving communication in libraries and information services

Purpose – This paper aims to examine the Self-Other Agreement between leaders and employees in the sector of Libraries and Information Services (LIS) to construct a sustainable and strategic communicational process among library directors and staff. Design/methodology/approach – A sample of 135 leaders-employees of 17 organisations of LIS in more than five countries answered on a quantitative methodological research instrument in a multiplicity of variables. Statistical analysis of independent samples t-test was used to testify our research hypotheses. Findings – Results indicated that there is a difference in means between the two independent samples (leaders-employees). There are library leaders who rate themselves quite high, and there are employees who rate their leaders with lower evaluations. Research limitations/implications – This research extends and improves the matter of Self-Other Agreement in the sector of LIS through the collection of data that indicated a possible gap of communication and trustworthiness between leaders and employees. Practical implications – Regardless of the difference or the consensus of ratings among leaders and employees, the results of this research could be served as a stimulus plus as a starting point for library leaders by correcting or developing relations of communication and trustworthiness between them and their followers. Originality/value – Self-Other Agreement is one of the major factors that positively or negatively affect the overall operation of the organization in the way a leader could perceive the additional feedback. In the sector of LIS, the study of Self-Other Agreement is a rich and unexplored research area which deserves further analysis

The impact of vascular burden on late-life depression.

Small vessel pathology and microvascular lesions are no longer considered as minor players in the fields of cognitive impairment and mood regulation. Although frequently found in cognitively intact elders, both neuroimaging and neuropathological data revealed the negative impact on cognitive performances of their presence within neocortical association areas, thalamus and basal ganglia. Unlike cognition, the relationship between these lesions and mood dysregulation is still a matter of intense debate. Early studies focusing on the role of macroinfarct location in the occurrence of post-stroke depression (PSD) led to conflicting data. Later on, the concept of vascular depression proposed a deleterious effect of subcortical lacunes and deep white matter demyelination on mood regulation in elders who experienced the first depressive episode. More recently, the chronic accumulation of lacunes in thalamus, basal ganglia and deep white matter has been considered as a strong correlate of PSD. We provide here a critical overview of neuroimaging and neuropathological sets of evidence regarding the affective repercussions of vascular burden in the aging brain and discuss their conceptual and methodological limitations. Based on these observations, we propose that the accumulation of small vascular and microvascular lesions constitutes a common neuropathological platform for both cognitive decline and depressive episodes in old age

Constraining tropospheric mixing timescales using airborne observations and numerical models

International audienceA technique is demonstrated for estimating atmospheric mixing time-scales from in-situ data, using a Lagrangian model initialised from an Eulerian chemical transport model (CTM). This method is applied to airborne tropospheric CO observations taken during seven flights of the Mediterranean Intensive Oxidant Study (MINOS) campaign, of August 2001. The time-scales derived, correspond to mixing applied at the spatial scale of the CTM grid. Specifically, they are upper bound estimates of the mix-down lifetime that should be imposed for a Lagrangian model to reproduce the observed small-scale tracer structure. They are relevant to the family of hybrid Lagrangian-Eulerian models, which impose Eulerian grid mixing to an underlying Lagrangian model. The method uses the fact that in Lagrangian tracer transport modelling, the mixing spatial and temporal scales are decoupled: the spatial scale is determined by the resolution of the initial tracer field, and the time scale by the trajectory length. The chaotic nature of lower-atmospheric advection results in the continuous generation of smaller spatial scales, a process terminated in the real atmosphere by mixing. Thus, a mix-down lifetime can be estimated by varying trajectory length so that the model reproduces the observed amount of small-scale tracer structure. Selecting a trajectory length is equivalent to choosing a mixing timescale. For the cases studied, the results are very insensitive to CO photochemical change calculated along the trajectories. The method is most appropriate for relatively homogeneous regions, i.e. it is not too important to account for changes in aircraft altitude or the positioning of stratospheric intrusions, so that small scale structure is easily distinguished. The chosen flights showed a range of mix-down time upper limits: 1 and 3 days for 8 August and 3 August, due to recent convective and boundary layer mixing respectively, and 7?9 days for 16, 17, 22a, 22c and 24 August. For the flight of 3 August, the observed concentrations result from a complex set of transport histories, and the models are used to interpret the observed structure, while illustrating where more caution is required with this method of estimating mix-down lifetimes

Spatio-temporal patterns of recent and future climate extremes in the eastern Mediterranean and Middle East region

Recent and future changes in temperature and precipitation climate extremes are estimated using the Hadley Centre PRECIS ("Providing REgional Climates for Impacts Studies") climate model for the eastern Mediterranean and Middle East region. The area of interest is considered vulnerable to extreme climate events as there is evidence for a temperature rise while precipitation tends to decline, suggesting likely effects on vital socioeconomic sectors in the region. Observations have been obtained for the recent period (1961–1990) and used to evaluate the model output. The spatial distribution of recent temporal trends in temperature indicates strong increasing in minimum temperature over the eastern Balkan Peninsula, Turkey and the Arabian Peninsula. The rate of warming reaches 0.4–0.5 °C decade⁻¹ in a large part of the domain, while warming is expected to be strongest in summer (0.6–0.7 °C decade⁻¹) in the eastern Balkans and western Turkey. The trends in annual and summer maximum temperature are estimated at approximately 0.5 and 0.6 °C decade⁻¹ respectively. Recent estimates do not indicate statistically significant trends in precipitation except for individual sub-regions. Results indicate a future warming trend for the study area over the last 30 years of the 21st century. Trends are estimated to be positive and statistically significant in nearly the entire region. The annual trend patterns for both minimum and maximum temperature show warming rates of approximately 0.4–0.6 °C decade⁻¹, with pronounced warming over the Middle Eastern countries. Summer temperatures reveal a gradual warming (0.5–0.9 °C decade⁻¹) over much of the region. The model projects drying trends by 5–30% in annual precipitation towards the end of the 21st century, with the number of wet days decreasing at the rate of 10–30 days year⁻¹, while heavy precipitation is likely to decrease in the high-elevation areas by 15 days year⁻¹

The effect of tertiary surveys on missed injuries in trauma:A systematic review

BACKGROUND: Trauma tertiary surveys (TTS) are advocated to reduce the rate of missed injuries in hospitalized trauma patients. Moreover, the missed injury rate can be a quality indicator of trauma care performance. Current variation of the definition of missed injury restricts interpretation of the effect of the TTS and limits the use of missed injury for benchmarking. Only a few studies have specifically assessed the effect of the TTS on missed injury. We aimed to systematically appraise these studies using outcomes of two common definitions of missed injury rates and long-term health outcomes. METHODS: A systematic review was performed. An electronic search (without language or publication restrictions) of the Cochrane Library, Medline and Ovid was used to identify studies assessing TTS with short-term measures of missed injuries and long-term health outcomes. ‘Missed injury’ was defined as either: Type I) any injury missed at primary and secondary survey and detected by the TTS; or Type II) any injury missed at primary and secondary survey and missed by the TTS, detected during hospital stay. Two authors independently selected studies. Risk of bias for observational studies was assessed using the Newcastle-Ottawa scale. RESULTS: Ten observational studies met our inclusion criteria. None was randomized and none reported long-term health outcomes. Their risk of bias varied considerably. Nine studies assessed Type I missed injury and found an overall rate of 4.3%. A single study reported Type II missed injury with a rate of 1.5%. Three studies reported outcome data on missed injuries for both control and intervention cohorts, with two reporting an increase in Type I missed injuries (3% vs. 7%, P<0.01), and one a decrease in Type II missed injuries (2.4% vs. 1.5%, P=0.01). CONCLUSIONS: Overall Type I and Type II missed injury rates were 4.3% and 1.5%. Routine TTS performance increased Type I and reduced Type II missed injuries. However, evidence is sub-optimal: few observational studies, non-uniform outcome definitions and moderate risk of bias. Future studies should address these issues to allow for the use of missed injury rate as a quality indicator for trauma care performance and benchmarking