Components, drivers and temporal dynamics of ecosystem respiration in a Mediterranean pine forest

To investigate the climate impacts on the different components of ecosystem respiration, we combined soil efflux data from a tree-girdling experiment with eddy covariance CO2 fluxes in a Mediterranean maritime pine (Pinus pinaster) forest in Central Italy. 73 trees were stem girdled to stop the flux of photosynthates from the canopy to the roots, and weekly soil respiration surveys were carried out for one year. Heterotrophic respiration (RH) was estimated from the soil CO2 flux measured in girdled plots, and rhizosphere respiration (RAb) was calculated as the difference between respiration from controls (RS) and girdled plots (RH). Results show that the RS dynamics were clearly driven by RH (average RH/RS ratio 0.74). RH predictably responded to environmental variables, being predominantly controlled by soil water availability during the hot and dry growing season (MayeOctober) and by soil temperature during the wetter and colder months (NovembereMarch). High RS and RH peaks were recorded after rain pulses greater than 10 mm on dry soil, indicating that large soil carbon emissions were driven by the rapid microbial oxidation of labile carbon compounds. We also observed a time-lag of one week between water pulses and RAb peaks, which might be due to the delay in the translocation of recently assimilated photosynthates from the canopy to the root system. At the ecosystem scale, total autotrophic respiration (RAt, i.e. the sum of carbon respired by the rhizosphere and aboveground biomass) amounted to 60% of ecosystem respiration. RAt was predominantly controlled by photosynthesis, and showed high temperature sensitivity (Q10) only during the wet periods. Despite the fact that the study coincided with an anomalous dry year and results might therefore not represent a general pattern, these data highlight the complex climatic control of the respiratory processes responsible for ecosystem CO2 emissions. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

JRC Ispra EMEP-GAW Regional Station for Atmospheric Research - 2007 Report

The aim of the JRC-Ispra station for atmospheric research (45°49'N, 8°38'E) is to monitor atmospheric parameters (pollutant concentrations and fluxes, atmospheric particle chemical composition, number size distribution and optical properties) to contribute in assessing the impact of European policies on air pollution and climate change. The station has been operated continuously since November 1985, with a gap in gas phase data due to a severe breakdown of the data acquisition system in 2003 though. The measurements performed in 2007 led to annual averages of ca. 32 µg m-3 O3, 0.8 µg m-3 SO2, 21 µg m-3 NO2 and 30 µg m-3 PM10. Carbonaceous species (organic matter plus elemental carbon) are the main constituents of PM2.5 (> 55 %) followed by NH4NO3 (20-30 %) and (NH4)2SO4 (10-20 %). The measurements confirmed the seasonal variations observed over the previous years, mainly driven by meteorology rather than by changes in emissions. Aerosol physical and optical properties were also measured in 2007. The average particle number (from 10 nm to 10 µm) was about 9200 cm-3 in 2007. The mean (close to dry) aerosol single scattering albedo (0.79) was low compared to the values generally observed in Europe, which means that the cooling effect of aerosols is reduced in our region compared to others. Long-term trends (over 20 years) show consistent decreases in sulfur concentrations and deposition, PM mass concentration (-0.9 µg m-3 yr-1) and in extreme ozone value occurrence frequency. The decreasing trends in oxidised and reduced nitrogen species are much less pronounced. However, historical minimum in NO3-, NH4+, (and SO42-) wet deposition, as well as in O3 pollution indicators (AOT40 and SOMO35) were observed in 2007.JRC.H.2-Climate chang

JRC Ispra EMEP - GAW Regional Station for Atmospheric Research - 2006 Report

The aim of the JRC-Ispra station for atmospheric research (45°49'N, 8°38'E) is to monitor atmospheric parameters (pollutant concentrations and fluxes, atmospheric particle chemical composition, number size distribution and optical properties) to contribute in assessing the impact of European policies on air pollution and climate change. The station has been operated continuously since November 1985, with a gap in gas phase data due to a severe breakdown of the data acquisition system in 2003 though. The measurements performed in 2006 led to annual averages of ca. 41 µg m-3 O3, 1.1 µg m-3 SO2, 21 µg m-3 NO2 and 33 µg m-3 PM10. Carbonaceous species (organic matter plus elemental carbon) are the main constituents of PM2.5 (> 50 %) followed by (NH4)2SO4 (10-20 %) and NH4NO3 (20-30 %). The measurements confirmed the seasonal variations observed over the previous years, mainly driven by meteorology rather than by changes in emissions. Aerosol physical and optical properties were also measured in 2006. The average particle number (from 6 nm to 10 µm) was about 10000 cm-3 in 2006. The mean (close to dry) aerosol single scattering albedo (a key parameter for determining the aerosol direct radiative forcing) was 0.79. Long-term trends (over 20 years) show decreases in sulfur concentrations and deposition, and in extreme ozone value occurrence frequency, although the latter was higher in compared to the last two years The decreasing trends in nitrogen oxides, reduced nitrogen species, and PM concentrations are much less pronounced.JRC.H.2-Climate chang

JRC Ispra EMEP - GAW Regional Station for Atmospheric Research 2008 Report

The aim of the JRC-Ispra station for atmospheric research (45°49'N, 8°38'E) is to monitor atmospheric parameters (pollutant concentrations and fluxes, atmospheric particle chemical composition, number size distribution and optical properties) to contribute in assessing the impact of European policies on air pollution and climate change. The station has been operated continuously since November 1985, with a gap in gas phase data due to a severe breakdown of the data acquisition system in 2003 though. The measurements performed in 2008 led to annual averages of ca. 34 µg m-3 O3, 0.7 µg m-3 SO2, 20 µg m-3 NO2 and 27 µg m-3 PM10. Carbonaceous species (organic matter plus elemental carbon) are the main constituents of PM2.5 (~57 %) followed by NH4NO3 (20-30 %) and (NH4)2SO4 (10-20 %). The data from 2008 confirmed the seasonal variations observed over the previous years, mainly driven by meteorology rather than by changes in emissions, as revealed by the lidar measurements. Aerosol physical and optical properties were also measured in 2008. The average particle number (from 10 nm to 10 µm) was about 8000 cm-3 in 2008. The mean (close to dry) aerosol single scattering albedo (0.75) was low compared to the values generally observed in Europe, which means that the cooling effect of aerosols is reduced in our region compared to others. Long-term trends (over 20 years) show consistent decreases in sulfur concentrations and deposition, PM mass concentration (-0.9 µg m-3 yr-1), and from 2003 in ozone concentrations too. The decreasing trends in oxidised and reduced nitrogen species are much less pronounced.JRC.H.2-Climate chang

JRC Ispra EMEP - GAW Regional Station for Atmospheric Research, 2009 Report

The aim of the JRC-Ispra station for atmospheric research (45°49¿N, 8°38¿E) is to monitor atmospheric parameters (pollutant concentrations and fluxes, atmospheric particle chemical composition, number size distribution and optical properties) to contribute in assessing the impact of European policies on air pollution and climate change. The station has been operated continuously since November 1985, with a gap in gas phase data in 2003 and 2009 due to a breakdown of the data acquisition system and lack of man-power, respectively. The measurements performed in 2009 led to annual average of 26.8 µg m-3 for PM10, well below the European annual limit value of 40 µg/m³ (the European directive 1999/30/EC for the year 2005 and onwards). In addition, the measurements performed in 2009 led to annual average of 19.0 µg m-3 for PM2.5, well below the future European annual limit value of 25 µg/m³ (European directive 2008/50/EC for the year 2015 and onwards). Carbonaceous species (organic matter plus elemental carbon) are the main constituents of PM2.5 (~57 %) followed by (NH4)2SO4 (24 %) and NH4NO3 (12 %). The data from 2009 confirmed the seasonal variations observed over the previous years, mainly driven by meteorology rather than by changes in emissions, as revealed by the lidar measurements. Aerosol physical and optical properties were also measured in 2009. The average particle number (from 10 nm to 10 µm) was about 7400 cm-3 and the mean geometric diameter was 70 nm. Their hygroscopic growth at 90% RH varies from <1.2 in December to 1.25 ¿ 1.35 (size dependent) in June. The mean (close to dry) aerosol single scattering albedo at ¿ = 550 nm was 0.76, and it was low compared to the values generally observed in Europe, which means that the cooling effect of aerosols is reduced in our region compared to others. Long-term trends (over 20 years) show consistent decreases in sulfur concentrations and deposition, PM mass concentration (about -0.9 µg m-3 yr-1), and from 2003 onwards also a slight decease in ozone concentrations too. The decreasing trends in oxidised and reduced nitrogen species are much less pronounced.JRC.DDG.H.2-Climate change and air qualit

JRC-Ispra Atmosphere - Biosphere - Climate Integrated monitoring Station: 2016 report

A comprehensive set of essential atmospheric variables have been measured at the JRC-Ispra Atmosphere - Biosphere - Climate Integrated monitoring Station (ABC-IS) for several years to assess the impact of European policies and international conventions on air pollution and climate forcing. The variables we measure at the Atmospheric Observatory in Ispra include greenhouse gas concentrations (CO2, CH4, N2O, SF6), radon (222Rn) activity concentration, short-lived gaseous and particulate pollutant (CO, SO2, NO, NO2, O3, PM2.5 and its main ionic and carbonaceous constituents) concentrations, atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (SO42-, NO3-, NH4+) wet deposition. Vegetation atmosphere exchanges (CO2, O3, H2O and heat) are measured at our Forest Flux Station of San Rossore, backed up by meteorological and pedological measurements. The ABC-IS 2016 report presents the data produced during the past year in the context of the previous years of measurements.JRC.C.5-Air and Climat

JRC – Ispra: Atmosphere – Biosphere – Climate Integrated monitoring Station: 2015 Report

A comprehensive set of essential atmospheric variables have been measured at the JRC-Ispra Atmosphere -Biosphere - Climate Integrated monitoring Station (ABC-IS) for several years to detect the impact of European policies and international conventions on air pollution and climate forcing. The variables we measure include greenhouse gas concentrations (CO2, CH4, N2O, SF6), radon (222Rn)activity concentration, short-lived gaseous and particulate pollutants (CO, SO2, NO, NO2, O3, PM2.5 and its main ionic and carbonaceous constituents), atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (SO42-, NO3-, NH4+) wet deposition, and vegetation atmosphere exchanges (CO2, O3, H2O and heat), backed up by meteorological and pedological measurements. All the measurements performed at ABC-IS are made under international projects and programs like InGOS (Integrated non-CO2 Greenhouse gas Observation System), ACTRIS (the EU research Infra-Structure for the observation of Aerosols, Clouds and TRace gases), EMEP (co-operative Program for Monitoring and Evaluation of the long range transmission of air pollutants in Europe) and GAW (Global Atmosphere Watch), which implies the use of standard methods and scales, and the participation in quality assurance activities. The JRC has a leading role in ACTRIS and EMEP regarding the quality assurance for carbonaceous aerosol measurements. All the data obtained at ABC-IS are submitted to international open data bases (www.europe-fluxdata.eu, fluxnet.ornl.gov, www.ingos-infrastructure.eu, ebas.nilu.no,) and can be freely downloaded from these web sites. The data we produce are used in European wide assessments, for model inputs and validation, and for calibrating satellite airborne sensors. The ABC-IS 2015 report presents the data produced during the past year in the context of the previous years of measurements.JRC.C.5-Air and Climat

Intercomparison Study of Six HTDMAs: Results and Recommendations

We report on an intercomparison of six different hygroscopicity tandem differential mobility analysers (HTDMAs). These HTDMAs are used worldwide in laboratory experiments and field campaigns to measure the water uptake of aerosol particles and have never been intercompared. After an investigation of the different design of the instruments with their advantages and inconveniencies, the methods for calibration, validation and data analysis are presented. Measurements of nebulised ammonium sulphate as well as of secondary organic aerosol generated from a smog chamber were performed. Agreement and discrepancies between the instruments and to the theory are discussed, and final recommendations for a standard instrument are given, as a benchmark for laboratory or field experiments to ensure a high quality of HTDMA data.JRC.H.2-Climate chang

Joint Research Centre 2018 light-duty vehicles emissions testing

This report presents the activities of the JRC on tailpipe emissions compliance assessment of light-duty vehicles conducted throughout 2018. Criteria pollutant and CO2 emissions of 19 vehicles were measured in the laboratory and on the road in a wide range of driving conditions. Distance-specific emissions for individual vehicles and per vehicle technologies and standards are presented. The methodology for emissions compliance defined in the Guidance on the evaluation of Auxiliary Emission Strategies and the presence of Defeat Devices with regard to the application of Regulation (EC) No 715/2007 on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) was applied and discussed.JRC.C.4-Sustainable Transpor

JRC – Ispra Atmosphere – Biosphere – Climate Integrated monitoring Station 2013 report

The Institute for Environment and Sustainability provides long-term observations of the atmosphere within international programs and research projects. These observations are performed from the research infrastructure named ABC-IS: Atmosphere – Biosphere – Climate Integrated monitoring Station. Most measurements are performed at the JRC-Ispra site, but observations are also carried out from two other platforms: the forest station in San Rossore, and a ship cruising in the Western Mediterranean sea. This document reports about the measurement programs, the equipment which is deployed, the data quality assessment, and the results obtained for each site. Our observations are presented, compared to each other, as well as to historical data obtained over more than 25 years at the Ispra site.JRC.H.2-Air and Climat