scholarly journals The regional impact of urban emissions on climate over central Europe: present and future emission perspective

2016 ◽  
Author(s):  
Peter Huszár ◽  
Michal Belda ◽  
Jan Karlický ◽  
Petr Pišoft ◽  
Tomáš Halenka
Keyword(s):  
Co2 Emissions ◽  
Central Europe ◽  
Regional Climate ◽  
Minor Role ◽  
Near Surface ◽  
Regional Impact ◽  
Radiative Impacts ◽  
A Minor ◽  
Urban Emissions ◽  
The Impact

Abstract. The regional climate model RegCM4.2 was coupled to the chemistry transport model CAMx, including two-way interactions, to evaluate the regional impact of urban emission from Central European cities on climate for present (2001–2010) and future (2046–2055). Short-lived non-CO2 emissions are considered, and, for the future impact, only the emission changes are accounted for (the climate is kept 'fixed'). The urban impact on climate is calculated with the annihilation approach, when two experiments are performed: one with all emissions included and one without considering urban emissions. The radiative impacts of non-CO2 primary and secondary formed pollutants are considered: namely ozone (O3), sulfates (PSO4), nitrates (PNO3), primary organic and elementary carbon (POA and PEC). The validation of the modeling system is limited to key climate parameters, near surface and precipitation. It shows that the model, in general, under-estimates temperature and overestimates precipitation. We attribute this behavior to too much cloudiness/water vapor present in the model atmosphere as a consequence of over-predicted evaporation from the surface. The impact on climate is characterized by a statistically significant cooling up to −0.02 K and −0.04 K in winter (DJF) and summer (JJA) season, mainly over cities. We found that the main contributor to the cooling is the aerosols direct and indirect effects, while the ozone titration, calculated especially for DJF, plays rather a minor role. In accordance with the vertical extent of the urban emission induced aerosol perturbation, cooling dominates the first few model layers up to about 150 m in DJF and 1000 m in JJA. We found a clear diurnal cycle of the radiative impacts with maximum cooling just after noon (JJA) or later in afternoon (DJF). Furthermore, statistically significant decreases of surface radiation are modeled, in accordance with the temperature decrease. The impact on the boundary later height is small but statistically significant and reaches −1 m and −6 m decreases in DJF and JJA, respectively. We did not find any statistically significant impact on precipitation and wind speed. Considering future emissions, the impacts are, in general, smaller – as a consequence of smaller emissions resulting in smaller urban induced chemical perturbations. In overall, the study suggest that the non-CO2 emissions play rather a minor role in modulating regional climate over central Europe. Much more important is the direct climate impact of urban surfaces trough urban canopy meteorological effects as we showed earlier.

scholarly journals The regional impact of urban emissions on climate over central Europe: present and future emission perspectives

2016 ◽  
Vol 16 (20) ◽  
pp. 12993-13013 ◽  
Author(s):  
Peter Huszár ◽  
Michal Belda ◽  
Jan Karlický ◽  
Petr Pišoft ◽  
Tomáš Halenka
Keyword(s):  
Co2 Emissions ◽  
Central Europe ◽  
Regional Climate ◽  
Minor Role ◽  
Regional Impact ◽  
Radiative Impacts ◽  
The Future ◽  
Emission Changes ◽  
A Minor ◽  
Urban Emissions

Abstract. The regional climate model RegCM4.2 was coupled to the chemistry transport model CAMx, including two-way interactions, to evaluate the regional impact of urban emission from central European cities on climate for present-day (2001–2010) and future (2046–2055) periods, and for the future one only emission changes are considered. Short-lived non-CO2 emissions are considered and, for the future impact, only the emission changes are accounted for (the climate is kept “fixed”). The urban impact on climate is calculated with the annihilation approach in which two experiments are performed: one with all emissions included and one without urban emissions. The radiative impacts of non-CO2 primary and secondary formed pollutants are considered, namely ozone (O3), sulfates (PSO4), nitrates (PNO3), primary organic aerosol and primary elementary carbon (POA and PEC).The validation of the modelling system is limited to key climate parameters, near-surface temperature and precipitation. It shows that the model, in general, underestimates temperature and overestimates precipitation. We attribute this behaviour to an excess of cloudiness/water vapour present in the model atmosphere as a consequence of overpredicted evaporation from the surface.The impact on climate is characterised by statistically significant cooling of up to −0.02 and −0.04 K in winter (DJF) and summer (JJA), mainly over cities. We found that the main contributors to the cooling are the direct and indirect effects of the aerosols, while the ozone titration, calculated especially for DJF, plays rather a minor role. In accordance with the vertical extent of the urban-emission-induced aerosol perturbation, cooling dominates the first few model layers up to about 150 m in DJF and 1000 m in JJA. We found a clear diurnal cycle of the radiative impacts with maximum cooling just after noon (JJA) or later in afternoon (DJF). Furthermore, statistically significant decreases of surface radiation are modelled in accordance with the temperature decrease. The impact on the boundary layer height is small but statistically significant and decreases by 1 and 6 m in DJF and JJA respectively. We did not find any statistically significant impact on precipitation and wind speed. Regarding future emissions, the impacts are, in general, smaller as a consequence of smaller emissions, resulting in smaller urban-induced chemical perturbations.In overall, the study suggest that the non-CO2 emissions play rather a minor role in modulating regional climate over central Europe. Much more important is the direct climate impact of urban surfaces via the urban canopy meteorological effects as we showed earlier.

scholarly journals The regional impact of urban emissions on air quality in Europe: the role of the urban canopy effects

2021 ◽  
Vol 21 (18) ◽  
pp. 14309-14332
Author(s):  
Peter Huszar ◽  
Jan Karlický ◽  
Jana Marková ◽  
Tereza Nováková ◽  
Marina Liaskoni ◽  
...  
Keyword(s):  
Air Quality ◽  
Land Surface ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Scale ◽  
Urban Canopy ◽  
Regional Climate Models ◽  
Near Surface ◽  
Urban Emissions ◽  
The Impact

Abstract. Urban areas are hot spots of intense emissions, and they influence air quality not only locally but on a regional or even global scale. The impact of urban emissions over different scales depends on the dilution and chemical transformation of the urban plumes which are governed by the local- and regional-scale meteorological conditions. These are influenced by the presence of urbanized land surface via the so-called urban canopy meteorological forcing (UCMF). In this study, we investigate for selected central European cities (Berlin, Budapest, Munich, Prague, Vienna and Warsaw) how the urban emission impact (UEI) is modulated by the UCMF for present-day climate conditions (2015–2016) using two regional climate models, the regional climate models RegCM and Weather Research and Forecasting model coupled with Chemistry (WRF-Chem; its meteorological part), and two chemistry transport models, Comprehensive Air Quality Model with Extensions (CAMx) coupled to either RegCM and WRF and the “chemical” component of WRF-Chem. The UCMF was calculated by replacing the urbanized surface by a rural one, while the UEI was estimated by removing all anthropogenic emissions from the selected cities. We analyzed the urban-emission-induced changes in near-surface concentrations of NO2, O3 and PM2.5. We found increases in NO2 and PM2.5 concentrations over cities by 4–6 ppbv and 4–6 µg m−3, respectively, meaning that about 40 %–60 % and 20 %–40 % of urban concentrations of NO2 and PM2.5 are caused by local emissions, and the rest is the result of emissions from the surrounding rural areas. We showed that if UCMF is included, the UEI of these pollutants is about 40 %–60 % smaller, or in other words, the urban emission impact is overestimated if urban canopy effects are not taken into account. In case of ozone, models due to UEI usually predict decreases of around −2 to −4 ppbv (about 10 %–20 %), which is again smaller if UCMF is considered (by about 60 %). We further showed that the impact on extreme (95th percentile) air pollution is much stronger, and the modulation of UEI is also larger for such situations. Finally, we evaluated the contribution of the urbanization-induced modifications of vertical eddy diffusion to the modulation of UEI and found that it alone is able to explain the modeled decrease in the urban emission impact if the effects of UCMF are considered. In summary, our results showed that the meteorological changes resulting from urbanization have to be included in regional model studies if they intend to quantify the regional footprint of urban emissions. Ignoring these meteorological changes can lead to the strong overestimation of UEI.

scholarly journals The regional impact of urban emissions on air quality in Europe: the role of the urban canopy effects

2021 ◽  
Author(s):  
Peter Huszar ◽  
Jan Karlický ◽  
Jana Marková ◽  
Tereza Nováková ◽  
Marina Liaskoni ◽  
...  
Keyword(s):  
Air Quality ◽  
Rural Areas ◽  
Land Surface ◽  
Urban Areas ◽  
Regional Climate ◽  
Regional Scale ◽  
Urban Canopy ◽  
Near Surface ◽  
Urban Emissions ◽  
The Impact

Abstract. Urban areas are hot-spots of intense emissions and they influence air-quality not only locally but on regional or even global scales. The impact of urban emissions over different scales depends on the dilution and chemical transformation of the urban plumes which are governed by the local and regional scale meteorological conditions. These are influenced by the presence of urbanized land-surface via the so called urban canopy meteorological forcing (UCMF). In this study, we investigate for selected central European cities (Berlin, Budapest, Munich, Prague, Vienna and Warsaw), how the urban emission impact (UEI) is modulated by the UCMF for present day climate conditions (2015–2016) using three regional climate-chemistry models: the regional climate models RegCM and WRF-Chem (its meteorological part), the chemistry transport model CAMx coupled to either RegCM and WRF and the “chemical” component of WRF-Chem. The UCMF was calculated by replacing the urbanized surface by rural one while the UEI was estimated by removing all anthropogenic emissions from the selected cities. We analyzed the urban emissions induced changes of near surface concentrations of NO2, O3 and PM2.5. We found increases of NO2 and PM2.5 concentrations over cities by 4–6 ppbv, and 4–6 μgm−3, respectively meaning that about 40–60 % and 20–40 % of urban concentrations of NO2 and PM2.5 are caused by local emissions and the rest is the result of emissions from surrounding rural areas. We showed that if UCMF is included, the UEI of these pollutants is about 40–60 % smaller, or in other words, the urban emission impact is overestimated if urban canopy effects are not taken into account. In case of ozone, models due to UEI usually predict decreases around −2 to −4 ppbv (about 10–20 %), which is again smaller if UCMF is considered (by about 60 %). We further showed that the impact on extreme (95th percentile) air-pollution is much stronger, as well as the modulation of UEI is larger for such situations. Finally, we evaluated the contribution of the urbanization induced modifications of vertical eddy-diffusion to the modulation of UEI, and found that it alone is able to explain the modelled decrease of the urban emission impact if the effects of UCMF are considered. In summary, our results showed that the meteorological changes resulting from urbanization have to be included in regional model studies if they intend to quantify the regional fingerprint of urban emissions. Ignoring these meteorological changes can lead to strong overestimation of UEI.

scholarly journals Analysis of Leading Cities in Central Europe: Control of Regional Economy

2011 ◽  
Vol 16 (16) ◽  
pp. 21-33 ◽  
Author(s):  
György Csomós
Keyword(s):  
Central Europe ◽  
Regional Economy ◽  
Science Studies ◽  
Stock Exchanges ◽  
Minor Role ◽  
Large Cities ◽  
Definition Of ◽  
A Minor ◽  
German Cities ◽  
Visegrad Group

Analysis of Leading Cities in Central Europe: Control of Regional EconomyNowadays, one of the characteristic orientations in social science studies focusing on cities is the ranking of cities, as well as the definition of the world's leading cities (world cities, global cities) on the basis of various criteria. Central European countries are given just a minor role in these researches, particularly in comparison with German cities with their considerable economic performance. This analysis compares the large cities of Austria, Germany and the countries of the Visegrád Group in terms of their role in economic leadership. To this end, the characteristic parameters have been examined: the GDP in purchasing power standards and nominal GDP of the cities, the revenues of large companies found in these cities, as well as the domestic market capitalization of the stock exchanges.

High Hopes

2020 ◽  
pp. 286-301
Author(s):  
Katja Lahikainen ◽  
Timo Pihkala ◽  
Elena Ruskovaara
Keyword(s):  
Regional Policy ◽  
Peripheral Region ◽  
Minor Role ◽  
Regional Impact ◽  
Regional Policies ◽  
A Minor ◽  
Lock In ◽  
The University ◽  
Technological University ◽  
Start Ups

The regional impact of entrepreneurial universities is a well-researched topic, but less attention is paid to the expectations of the regional policy institutes toward the university. This chapter investigates the regional policy expectations toward the university and what the influence of the university to these expectations is. This study is based on a technological university case in a peripheral region in Finland. The results of the study show that the existence of a single university leads easily to a university-dominant policy and thus to a regional policy lock-in. Consequently, the implementation of the regional policies can be in the hands of the university, leaving other regional stakeholders with a minor role. In order to fully utilize the potential of the university to address the specific regional challenges, the university should not only be seen as a locus of new spin-offs and start-ups, but rather as a producer of qualified graduates and future entrepreneurs.

scholarly journals 2-way coupling the hydrological land surface model PROMET with the regional climate model MM5

2013 ◽  
Vol 17 (5) ◽  
pp. 1705-1714 ◽  
Author(s):  
F. Zabel ◽  
W. Mauser
Keyword(s):  
Heat Flux ◽  
Land Surface ◽  
Regional Climate ◽  
Surface Processes ◽  
Surface Model ◽  
Land Surface Processes ◽  
Near Surface ◽  
Danube Catchment ◽  
Simulated Precipitation ◽  
The Impact

Abstract. Most land surface hydrological models (LSHMs) consider land surface processes (e.g. soil–plant–atmosphere interactions, lateral water flows, snow and ice) in a spatially detailed manner. The atmosphere is considered as exogenous driver, neglecting feedbacks between the land surface and the atmosphere. On the other hand, regional climate models (RCMs) generally simulate land surface processes through coarse descriptions and spatial scales but include land–atmosphere interactions. What is the impact of the differently applied model physics and spatial resolution of LSHMs on the performance of RCMs? What feedback effects are induced by different land surface models? This study analyses the impact of replacing the land surface module (LSM) within an RCM with a high resolution LSHM. A 2-way coupling approach was applied using the LSHM PROMET (1 × 1 km2) and the atmospheric part of the RCM MM5 (45 × 45 km2). The scaling interface SCALMET is used for down- and upscaling the linear and non-linear fluxes between the model scales. The change in the atmospheric response by MM5 using the LSHM is analysed, and its quality is compared to observations of temperature and precipitation for a 4 yr period from 1996 to 1999 for the Upper Danube catchment. By substituting the Noah-LSM with PROMET, simulated non-bias-corrected near-surface air temperature improves for annual, monthly and daily courses when compared to measurements from 277 meteorological weather stations within the Upper Danube catchment. The mean annual bias was improved from −0.85 to −0.13 K. In particular, the improved afternoon heating from May to September is caused by increased sensible heat flux and decreased latent heat flux as well as more incoming solar radiation in the fully coupled PROMET/MM5 in comparison to the NOAH/MM5 simulation. Triggered by the LSM replacement, precipitation overall is reduced; however simulated precipitation amounts are still of high uncertainty, both spatially and temporally. The distribution of precipitation follows the coarse topography representation in MM5, resulting in a spatial shift of maximum precipitation northwards of the Alps. Consequently, simulation of river runoff inherits precipitation biases from MM5. However, by comparing the water balance, the bias of annual average runoff was improved from 21.2% (NOAH/MM5) to 4.4% (PROMET/MM5) when compared to measurements at the outlet gauge of the Upper Danube watershed in Achleiten.

scholarly journals Modeling the present and future impact of aviation on climate: an AOGCM approach with online coupled chemistry

2013 ◽  
Vol 13 (19) ◽  
pp. 10027-10048 ◽  
Author(s):  
P. Huszar ◽  
H. Teyssèdre ◽  
M. Michou ◽  
A. Voldoire ◽  
D. J. L. Olivié ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
General Circulation ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Climate Impacts ◽  
Ozone Production ◽  
The Arctic ◽  
Near Surface ◽  
Aviation Emissions ◽  
The Impact

Abstract. Our work is among the first that use an atmosphere-ocean general circulation model (AOGCM) with online chemistry to evaluate the impact of future aviation emissions on temperature. Other particularities of our study include non-scaling to the aviation emissions, and the analysis of models' transient response using ensemble simulations. The model we use is the Météo-France CNRM-CM5.1 earth system model extended with the REPROBUS chemistry scheme. The time horizon of our interest is 1940–2100, assuming the A1B SRES scenario. We investigate the present and future impact of aviation emissions of CO2, NOx and H2O on climate, taking into account changes in greenhouse gases, contrails and contrail-induced cirrus (CIC). As in many transport-related impact studies, we distinguish between the climate impacts of CO2 emissions and those of non-CO2 emissions. Aviation-produced aerosol is not considered in the study. Our modeling system simulated a notable sea-ice bias in the Arctic, and therefore results concerning the surface should be viewed with caution. The global averaged near-surface CO2 impact reaches around 0.1 K by the end of the 21st century, while the non-CO2 impact reaches 0.2 K in the second half of the century. The NOx emissions impact is almost negligible in our simulations, as our aviation-induced ozone production is small. As a consequence, the non-CO2 signal is very similar to the CIC signal. The seasonal analysis shows that the strongest warming due to aviation is modeled for the late summer and early autumn. In the stratosphere, a significant cooling is attributed to aviation CO2 emissions (−0.25 K by 2100). A −0.3 K temperature decrease is modeled when considering all the aviation emissions, but no significant signal appears from the CIC or NOx forcings in the stratosphere.

scholarly journals Extracellular Pneumococcal Serine Proteases Affect Nasopharyngeal Colonization

2021 ◽  
Vol 10 ◽  
Author(s):  
Murtadha Q. Ali ◽  
Thomas P. Kohler ◽  
Gerhard Burchhardt ◽  
Andreas Wüst ◽  
Nadin Henck ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Bacterial Load ◽  
Acute Infection ◽  
Minor Role ◽  
Extracellular Proteases ◽  
Nasopharyngeal Colonization ◽  
Invasive Diseases ◽  
Pneumococcal Colonization ◽  
A Minor ◽  
The Impact

Streptococcus pneumoniae has evolved versatile strategies to colonize the nasopharynx of humans. Colonization is facilitated by direct interactions with host cell receptors or via binding to components of the extracellular matrix. In addition, pneumococci hijack host-derived extracellular proteases such as the serine protease plasmin(ogen) for ECM and mucus degradation as well as colonization. S. pneumoniae expresses strain-dependent up to four serine proteases. In this study, we assessed the role of secreted or cell-bound serine proteases HtrA, PrtA, SFP, and CbpG, in adherence assays and in a mouse colonization model. We hypothesized that the redundancy of serine proteases compensates for the deficiency of a single enzyme. Therefore, double and triple mutants were generated in serotype 19F strain EF3030 and serotype 4 strain TIGR4. Strain EF3030 produces only three serine proteases and lacks the SFP encoding gene. In adherence studies using Detroit-562 epithelial cells, we demonstrated that both TIGR4Δcps and 19F mutants without serine proteases or expressing only CbpG, HtrA, or PrtA have a reduced ability to adhere to Detroit-562 cells. Consistent with these results, we show that the mutants of strain 19F, which preferentially colonizes mice, abrogate nasopharyngeal colonization in CD-1 mice after intranasal infection. The bacterial load in the nasopharynx was monitored for 14 days. Importantly, mutants showed significantly lower bacterial numbers in the nasopharynx two days after infection. Similarly, we detected a significantly reduced pneumococcal colonization on days 3, 7, and 14 post-inoculations. To assess the impact of pneumococcal serine proteases on acute infection, we infected mice intranasally with bioluminescent and invasive TIGR4 or isogenic triple mutants expressing only CbpG, HtrA, PrtA, or SFP. We imaged the acute lung infection in real-time and determined the survival of the mice. The TIGR4lux mutant expressing only PrtA showed a significant attenuation and was less virulent in the acute pneumonia model. In conclusion, our results showed that pneumococcal serine proteases contributed significantly to pneumococcal colonization but played only a minor role in pneumonia and invasive diseases. Because colonization is a prerequisite for invasive diseases and transmission, these enzymes could be promising candidates for the development of antimicrobials to reduce pneumococcal transmission.

scholarly journals Seasonal Changes of the Airborne Microbiome in a Large Urban Area

2020 ◽  
Author(s):  
Andrés Núñez ◽  
Diego A Moreno ◽  
Ana M García ◽  
Raul Guantes
Keyword(s):  
Disease Outbreaks ◽  
Urban Environments ◽  
Minor Role ◽  
Near Surface ◽  
Surface Atmosphere ◽  
Ecological Importance ◽  
Bacteria And Fungi ◽  
A Minor

Abstract Background Compared to soil or aquatic ecosystems, the atmosphere is still an underexplored environment for microbial diversity. Besides its ecological importance, the spatial and temporal characterization of aerosolized microorganisms is relevant for understanding allergy and disease outbreaks, especially in highly populated cities. Results In this study, we surveyed the composition, variability and sources of microbes (bacteria and fungi) in the near surface atmosphere of a highly populated area, spanning ~ 4,000 Km 2 around the city center of Madrid (Spain), in different seasonal periods along two years. We found a core of abundant bacterial genera robust across space and time, most of soil origin, while fungi were more sensitive to environmental conditions. Microbial communities showed clear seasonal patterns driven by variability of environmental factors, mainly temperature and accumulated rain, while local sources played a minor role. We also identified taxa in both kingdoms characteristic of seasonal periods, but not of specific sampling sites or plant coverage. Conclusions The present study suggests that the near surface atmosphere of urban environments constitutes a stable ecosystem, with a relatively homogenous composition, modulated by climatic variations. As such, it contributes to our understanding of the long-term changes associated to the human exposome in the air of highly populated areas.

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