E. Katragkou

An Assessment of the Efficiency of Dust Regional Modelling to Predict Saharan Dust Transport Episodes

Aerosol levels at Mediterranean Basin are significantly affected by desert dust that is eroded in North Africa and is transported northwards. This study aims to assess the performance of the Dust REgional Atmospheric Model (BSC-DREAM8b) in the prediction of dust outbreaks near the surface in Eastern Mediterranean. For this purpose, model PM10 predictions covering a 7-year period and PM10 observations at five surface monitoring sites in Greece are used. A quantitative criterion is set to select the significant dust outbreaks defined as those when the predicted PM10 surface concentration exceeds 12 μg/m3. The analysis reveals that significant dust transport is usually observed for 1–3 consecutive days. Dust outbreak seasons are spring and summer, while some events are also forecasted in autumn. The seasonal variability of dust transport events is different at Finokalia, where the majority of events are observed in spring and winter. Dust contributes by 19–25% to the near surface observed PM10 levels, which can be increased to more than 50 μg/m3 during dust outbreaks, inducing violations of the air quality standards. Dust regional modeling can be regarded as a useful tool for air quality managers when assessing compliance with air quality limit values.

MOSESS: A New Emission Model for the Compilation of Model-Ready Emission Inventories—Application in a Coal Mining Area in Northern Greece

Over the last years, the capabilities of chemical transport models have been greatly improved and the need for more accurate emission data has increased as well. In the past, a number of emission models have been developed and present different functionalities and applications. The majority of these though cover very specific needs. This paper describes the development of a new emission model namely computer model for the construction of model-ready emission inventories (MOSESS) which is used to compile high-resolution emission inventories or improve existing ones, utilizing complex GIS techniques. The model aims in helping chemical modelers to obtain a better overview of their modeling application by having a comprehensive understanding of the emission input. MOSESS incorporates more than 70 different emission calculation methodologies, and it is capable of handling external emission databases (such as EMEP and EPER) from which emissions can be extracted. The temporal variation (annual/daily and diurnal processing), chemical speciation of NMVOCs and particles, vertical distribution and point source treatment, as well as the spatial disaggregation of emissions (utilizing numerous spatial proxies including high-resolution landuses) can help create model-ready emission inventories which can be used for contemporary modeling applications.

Land‐atmosphere coupling in EURO‐CORDEX evaluation experiments

The authors like to thank the coordination and the participating institutes of the EURO‐CORDEX initiative for making this study possible. The contribution from Centre de Recherche Public‐Gabriel Lippmann (labeled here as “MIUB”) (now Luxembourg Institute of Science and Technology, LIST) was funded by the Luxembourg National Research Fund (FNR) through grant FNR C09/SR/16 (CLIMPACT). The John von Neumann Institute for Computing and the Forschungszentrum Julich provided the required compute time for the project JJSC15. Work is furthermore sponsored through a research and development cooperation on hydrometeorology between the Federal Institute of Hydrology, Koblenz, Germany, and the Meteorological Institute, University of Bonn, Bonn, Germany. The KNMI‐RACMO simulation was supported by the Dutch Ministry of Infrastructure and the Environment. The simulations of the Universidad de Cantabria were supported by the CORWES project (CGL2010‐22158‐C02), funded by the Spanish R&D Programme and by the FP7 grant 308291 (EUPORIAS). We acknowledge Santander Supercomputacion support group at the University of Cantabria, who provided access to the Altamira Supercomputer at the Institute of Physics of Cantabria (IFCA‐CSIC), member of the Spanish Supercomputing Network. Rowan Fealy acknowledges the financial support provided by the Irish Environmental Protection Agency and the use of Maynooth Universitys high‐performance computer and the Irish Centre for High End Computing (ICHEC) Stokes facility. The work done by Rita M. Cardoso and Pedro M.M. Soares was financed the Portuguese Science Foundation (FCT) under Project SOLAR‐PTDC/GEOMET/7078/2014. The work of University of Hohenheim as part of the Project RU 1695 was funded by German Science Foundation (DFG). WRF‐UHOH simulations were carried out at the supercomputing center HLRS in Stuttgart (Germany). The CLMcom‐CCLM simulation was supported by the German Federal Ministry of Education and Research (BMBF) and the German Climate Computing Centre (DKRZ). AUTH‐DMC acknowledges the technical support of AUTH‐Scientific Computing Center, the HellasGrid/EGI infrastructure, and the financial support of AUTH‐Research Committee (Pr.Nr. 91376 and 87783). This work used eddy covariance data acquired by the FLUXNET community. We acknowledge the financial support to the eddy covariance data harmonization (www.fluxdata.org). The ERA‐Interim data were accessed from http://apps.ecmwf.int/datasets/. The GLEAM data were accessed from www.gleam.eu/#downloads. The analysis results and the underlying RCM data base are available upon request (sknist@uni‐bonn.de). The data are archived at the Julich Supercomputing Centre, Research Centre Julich, Julich, Germany. We thank the anonymous reviewers for their detailed and constructive comments.

Is the ozone climate penalty robust in Europe

Ozone air pollution is identified as one of the main threats bearing upon human health and ecosystems, with 25 000 deaths in 2005 attributed to surface ozone in Europe (IIASA 2013 TSAP Report #10). In addition, there is a concern that climate change could negate ozone pollution mitigation strategies, making them insufficient over the long run and jeopardising chances to meet the long term objective set by the European Union Directive of 2008 (Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008) (60 ppbv, daily maximum). This effect has been termed the ozone climate penalty. One way of assessing this climate penalty is by driving chemistry-transport models with future climate projections while holding the ozone precursor emissions constant (although the climate penalty may also be influenced by changes in emission of precursors). Here we present an analysis of the robustness of the climate penalty in Europe across time periods and scenarios by analysing the databases underlying 11 articles published on the topic since 2007, i.e. a total of 25 model projections. This substantial body of literature has never been explored to assess the uncertainty and robustness of the climate ozone penalty because of the use of different scenarios, time periods and ozone metrics. Despite the variability of model design and setup in this database of 25 model projection, the present meta-analysis demonstrates the significance and robustness of the impact of climate change on European surface ozone with a latitudinal gradient from a penalty bearing upon large parts of continental Europe and a benefit over the North Atlantic region of the domain. Future climate scenarios present a penalty for summertime (JJA) surface ozone by the end of the century (2071–2100) of at most 5 ppbv. Over European land surfaces, the 95% confidence interval of JJA ozone change is [0.44; 0.64] and [0.99; 1.50] ppbv for the 2041–2070 and 2071–2100 time windows, respectively.

Climate change impact assessment of air pollution levels in bulgaria

The presented work is aiming at climate change impacts and vulnerability assessment in Bulgaria Climate change may affect exposures to air pollutants by affecting weather and thereby local and regional pollution concentrations Local weather patterns influence atmospheric chemical reactions and can also affect atmospheric transport and deposition processes. US EPA Models-3 System for a region with resolution of 10 km covering Bulgaria is exploited here The meteorological background is produced by the climatic version of ALADIN weather forecast system TNO emission inventory for 2000 is used The chemical boundary conditions are extracted from 50-km resolution runs over Europe made in Aristotle University of Thessaloniki, Greece Calculations for the period 1991-2000 are performed, results presented in a study For year 2000, some scenarios are run, results compared with measured data.

Optimization of a Regional Climate Model for High Resolution Simulations over Greece

A set of six yearly high resolution (10 × 10 km) regional climate simulations were carried out over Greece using RegCM3 in the framework of the project GEOCLIMA based on different setups for the convective scheme. Specifically, the simulations comprised two experiments using the Grell convective scheme with Fritsch-Chappell (FC) closure assumption and four experiments using the Emanuel convective scheme. The aim of the study is the optimization of the model for Greece by comparing simulated values of near surface temperature, precipitation and cloudiness with the respective observed values at 84 Greek stations. The model domain is nested to a coarser RegCM3 European domain (at a resolution of 25 × 25 km) driven by the ERA-40 reanalysis dataset. Simulations using the modified Emanuel convective scheme reduce mean bias (and RMSE) in temperature over 25% (20%), in cloudiness over 20% (10%) and in precipitation over 70% (40%). Results show that the model for the Greek area is more sensitive to changes in autoconversion threshold than changes in relaxation rate.

Decadal Analysis of Heat-Wave Events in Thessaloniki and Investigation of Impacts on PM10

The aim of this paper is to analyze the heat wave events during the decade 2001–2010 over Thessaloniki and the determination of their basic characteristics. Since extreme weather events are accompanied by serious pollution episodes, the potential linkages of heat wave events with high particulate matter (PM10) concentrations are investigated. In order to describe the heat wave events we use the Temperature Humidity Index (THI) and we classify accordingly the days fulfilling the heatwave criteria. PM10 measurements at two monitoring stations in Thessaloniki are used in order to investigate their potential linkage to the extreme meteorological events. In the urban background station of Panorama the distribution of PM10 is shifted to higher size bins and the mean of the distribution increases by 6 μg/m3 during the heatwave days. At the urban station of Agia Sofia, the impact of heatwave on PM10 pollution on the PM10 distribution is weaker, due to masking effects of the local (traffic) emission sources.

A system for assessment of climatic air pollution levels in Bulgaria: description and first steps towards validation

The EC FP6 project CECILIA (http://www.cecilia-eu.org) aims at climate change impacts and vulnerability assessment in targeted areas of Central and Eastern Europe. Emphasis is given to regional climate change modeling at resolution of 10 km. The respective weather patterns influence local air quality. For its assessment EPA Models-3 (MM5, CMAQ, SMOKE) is used. The meteorological input is produced by the climatic version of ALADIN weather forecast system. TNO emission inventory for 2000 is exploited. The boundary conditions are extracted from 50-km runs over Europe made in Aristotle University of Thessaloniki, Greece. Calculations for the period 1991–2000 are performed, results presented.

Background pollution forecast over bulgaria

Both, the current level of air pollution studies and social needs in the country, are in a stage mature enough for creating Bulgarian Chemical Weather Forecasting and Information System The system is foreseen to provide in real time forecast of the spatial/temporal Air Quality behaviour for the country and (with higher resolution) for selected sub-regions and cities on the base of the weather forecast and national emission inventory. The country-scale part of the system is designed It is based on the US EPA Models-3 System The meteorological input is the ALADIN output, ALADIN being the national numerical weather forecast tool The boundary conditions are prepared by a similar system running operationally in Aristotle University of Thessaloniki, Greece (AUTH) Special interface is created to retrieve in real time the AUTH-system forecasts producing boundary files uploaded to dedicated server in Bulgaria. In the paper, detailed description of the System will be given together with first results of its testing.

Simulated Dust Over the Sahara and Mediterranean with a Regional Climate Model (RegCM4)

The present study focuses on the evaluation of dust in on-line chemistry-climate simulations with the regional climate model RegCM4. The simulations cover the period from December 2006 to November 2014 and use the new dust scheme implemented in RegCM4 that splits 12 dust size groups according to the changes of dry deposition velocity with size (isogradient method). In the model, dust is emitted over desert and semidesert grid cells when a wind speed threshold value is exceeded. This critical wind speed value varies and depends on soil particle size distribution, surface roughness and soil moisture.