Malnes E.,Norut |
Buanes A.,Norut |
Nagler T.,ENVEO |
Bippus G.,ENVEO |
And 9 more authors.
Cryosphere | Year: 2015
CryoLand (2011-2015) is a project carried out within the 7th Framework of the European Commission aimed at developing downstream services for monitoring seasonal snow, glaciers and lake/river ice primarily based on satellite remote sensing. The services target private and public users from a wide variety of application areas, and aim to develop sustainable services after the project is completed. The project has performed a thorough user requirement survey in order to derive targeted requirements for the service and provide recommendations for the design and priorities of the service. In this paper we describe the methods used, the major findings in this user survey, and how we used the results to design and specify the CryoLand snow and land ice service. The user requirement analysis shows that a European operational snow and land ice service is required and that there exists developed cryosphere products that can meet the specific needs. The majority of the users were mainly interested not only in the snow services, but also the lake/river ice products and the glacier products were desired. © Author(s) 2015.
Panagos P.,European Commission - Joint Research Center Ispra |
Borrelli P.,European Commission - Joint Research Center Ispra |
Spinoni J.,European Commission - Joint Research Center Ispra |
Ballabio C.,European Commission - Joint Research Center Ispra |
And 17 more authors.
Water (Switzerland) | Year: 2016
As a follow up and an advancement of the recently published Rainfall Erosivity Database at European Scale (REDES) and the respective mean annual R-factor map, the monthly aspect of rainfall erosivity has been added to REDES. Rainfall erosivity is crucial to be considered at a monthly resolution, for the optimization of land management (seasonal variation of vegetation cover and agricultural support practices) as well as natural hazard protection (landslides and flood prediction). We expanded REDES by 140 rainfall stations, thus covering areas where monthly R-factor values were missing (Slovakia, Poland) or former data density was not satisfactory (Austria, France, and Spain). The different time resolutions (from 5 to 60 min) of high temporal data require a conversion of monthly R-factor based on a pool of stations with available data at all time resolutions. Because the conversion factors show smaller monthly variability in winter (January: 1.54) than in summer (August: 2.13), applying conversion factors on a monthly basis is suggested. The estimated monthly conversion factors allow transferring the R-factor to the desired time resolution at a European scale. The June to September period contributes to 53% of the annual rainfall erosivity in Europe, with different spatial and temporal patterns depending on the region. The study also investigated the heterogeneous seasonal patterns in different regions of Europe: on average, the Northern and Central European countries exhibit the largest R-factor values in summer, while the Southern European countries do so from October to January. In almost all countries (excluding Ireland, United Kingdom and North France), the seasonal variability of rainfall erosivity is high. Very few areas (mainly located in Spain and France) show the largest from February to April. The average monthly erosivity density is very large in August (1.67) and July (1.63), while very small in January and February (0.37). This study addresses the need to develop monthly calibration factors for seasonal estimation of rainfall erosivity and presents the spatial patterns of monthly rainfall erosivity in European Union and Switzerland. Moreover, the study presents the regions and seasons under threat of rainfall erosivity. © 2016 by the authors.
Schulze E.D.,Max Planck Institute for Biogeochemistry |
Ciais P.,CEA Saclay Nuclear Research Center |
Luyssaert S.,CEA Saclay Nuclear Research Center |
Schrumpf M.,Max Planck Institute for Biogeochemistry |
And 21 more authors.
Global Change Biology | Year: 2010
Overviewing the European carbon (C), greenhouse gas (GHG), and non-GHG fluxes, gross primary productivity (GPP) is about 9.3 Pg yr-1, and fossil fuel imports are 1.6 Pg yr-1. GPP is about 1.25% of solar radiation, containing about 360 × 1018 J energy - five times the energy content of annual fossil fuel use. Net primary production (NPP) is 50%, terrestrial net biome productivity, NBP, 3%, and the net GHG balance, NGB, 0.3% of GPP. Human harvest uses 20% of NPP or 10% of GPP, or alternatively 1‰ of solar radiation after accounting for the inherent cost of agriculture and forestry, for production of pesticides and fertilizer, the return of organic fertilizer, and for the C equivalent cost of GHG emissions. C equivalents are defined on a global warming potential with a 100-year time horizon. The equivalent of about 2.4% of the mineral fertilizer input is emitted as N2O. Agricultural emissions to the atmosphere are about 40% of total methane, 60% of total NO-N, 70% of total N2O-N, and 95% of total NH3-N emissions of Europe. European soils are a net C sink (114 Tg yr-1), but considering the emissions of GHGs, soils are a source of about 26 Tg CO2 C-equivalent yr-1. Forest, grassland and sediment C sinks are offset by GHG emissions from croplands, peatlands and inland waters. Non-GHGs (NH3, NOx) interact significantly with the GHG and the C cycle through ammonium nitrate aerosols and dry deposition. Wet deposition of nitrogen (N) supports about 50% of forest timber growth. Land use change is regionally important. The absolute flux values total about 50 Tg C yr-1. Nevertheless, for the European trace-gas balance, land-use intensity is more important than land-use change. This study shows that emissions of GHGs and non-GHGs significantly distort the C cycle and eliminate apparent C sinks. © 2010 Blackwell Publishing Ltd.
Freney E.,CNRS Laboratory of Physics and Meteorology |
Freney E.,French National Center for Scientific Research |
Karine S.,CNRS Laboratory of Physics and Meteorology |
Karine S.,French National Center for Scientific Research |
And 16 more authors.
Aerosol and Air Quality Research | Year: 2016
Aerosol particles emitted by both natural and anthropogenic sources have direct and indirect radiative impacts. Within the planetary mixing layer (ML), these particles are subjected to a large number of removal processes, e.g., rain, sedimentation, coagulation, and thus have a relatively short lifetime. Once aerosols are transported into the free troposphere (FT), their atmospheric lifetime increases significantly and they tend to be representative of large spatial areas. The work presented here shows evidence of anthropogenic emissions being transported from the ML to the FT during a cold period in February 2012. Using a wide range of in-situ measurements of aerosol chemical and physical properties at the Puy de Dome (PUY) station, as well as LIDAR measurements (at the Cezeaux site) of atmospheric back scattering we studied the exchange between the ML and the FT. Criteria used to identify when the PUY station was sampling in the ML or in the FT included mixing layer height estimates from LIDAR measurements, trace gas measurements, and air mass trajectories. Within the FT, we observed a gradual change in aerosol physical properties with increases in aerosol mass concentrations of up to 2 times the starting concentration, as well as increases in the number of larger particles (particle diameter >150 nm). Aerosol chemical properties showed increases in organic and nitrate particles. A series of linear fits were made through the data providing information on how different parameters change as a function of time. The impact of these changing aerosol properties are discussed in relation to the potential influence on aerosol direct and indirect effects. This work presents a unique combination of observations, and provide valuable data for future model validation. © Taiwan Association for Aerosol Research.
Stefancova L.,Czech Institute of Chemical Process Fundamentals |
Schwarz J.,Czech Institute of Chemical Process Fundamentals |
Makela T.,Finish Meteorological Institute |
Hillamo R.,Finish Meteorological Institute |
Smolik J.,Czech Institute of Chemical Process Fundamentals
Aerosol Science and Technology | Year: 2011
Two cascade impactors, a Berner Low Pressure Impactor (BLPI model 25/0.018) and a modified BLPI (with a lower pressure drop) were characterized experimentally. First, the critical dimensions of each impactor stage that affect the collection characteristics were measured. Second, the absolute pressures at each stage were determined. Finally, the collection efficiency curves were obtained for all stages in a range of particle sizes from 0.026-13.7 μm. The collection efficiency of the modified impactor was measured using two condensation particle counters (CPC). Monodisperse calibration particles in the submicron size range were generated with a differential mobility analyzer (DMA). A vibrating orifice aerosol generator (VOAG) was used to produce supermicron test particles. In addition, the particle losses of both impactors were experimentally tested using ammonium sulfate particles under dry (15% RH) and wet (> 80% RH) conditions. The losses were determined by rinsing a sampling foil and the corresponding impactor stage (nozzle plate, walls and spacer ring) with deionized water. Subsequently, the ammonium sulfate contents of the samples, along with the rinse water, were analyzed using ion chromatography. Copyright © American Association for Aerosol Research.
Comment on "Trends and low frequency variability of extra-tropical cyclone activity in the ensemble of twentieth century reanalysis" by Xiaolan L. Wang, Y. Feng, G. P. Compo, V. R. Swail, F. W. Zwiers, R. J. Allan, and P. D. Sardeshmukh, Climate Dynamics, 2012
Krueger O.,University of Edinburgh |
Krueger O.,Helmholtz Center Geesthacht |
Feser F.,Helmholtz Center Geesthacht |
Barring L.,Rossby Center |
And 4 more authors.
Climate Dynamics | Year: 2014
The main subject of this article is to comment on the issue of storminess trends derived from the twentieth century reanalysis (20CR) and from observations in the North Atlantic region written about in Wang et al. (Clim Dyn 40(11-12):2775-2800, 2012). The statement that the 20CR estimates would be consistent with storminess derived from pressure-based proxies does not hold for the time prior to 1950. © 2013 Springer-Verlag Berlin Heidelberg.
Illingworth A.J.,University of Reading |
Cimini D.,CNR Institute of Neuroscience |
Cimini D.,University of L'Aquila |
Gaffard C.,UK Met Office |
And 5 more authors.
Bulletin of the American Meteorological Society | Year: 2015
A recent Cooperation in Science and Technology (COST) action financed by the European Union, European Ground-Based Observations of Essential Variables for Climate and Operational Meteorology (EG-CLIMET) is reported. The final report identified four ground-based profiling instruments that are currently underexploited and that have the potential to provide profiles of aerosol and cloud backscatter, winds, temperature, and humidity in real time. These include automatic lidars and ceilometers (ALCs), Doppler lidars, wind profilers, and microwave radiometers. Low-power and sensitive ALCs transmit a short pulse of laser radiation, with wavelengths ranging from 355 to 1064 nm, and receive a backscattered signal with a delay that provides range information. Doppler lidars have the ability to continuously monitor the wind vector throughout the boundary layer using the return from aerosol particles and that the instruments can operate unmanned with minimal maintenance. The precise estimation of Doppler frequencies is performed through heterodyning followed by spectral estimation methods and only requires sufficiently stable radio frequency (RF) oscillators.
Ilie R.,University of Michigan |
Ganushkina N.,University of Michigan |
Ganushkina N.,Finish Meteorological Institute |
Toth G.,University of Michigan |
And 2 more authors.
Journal of Geophysical Research A: Space Physics | Year: 2015
We investigate the configuration of the geomagnetic field on the nightside magnetosphere during a quiet time interval based on National Oceanic and Atmospheric Administration Polar Orbiting Environment Satellites Medium Energy Proton and Electron Detector (NOAA/POES MEPED) measurements in combination with numerical simulations of the global terrestrial magnetosphere using the Space Weather Modeling Framework. Measurements from the NOAA/POES MEPED low-altitude data sets provide the locations of isotropic boundaries; those are used to extract information regarding the field structure in the source regions in the magnetosphere. In order to evaluate adiabaticity and mapping accuracy, which is mainly controlled by the ratio between the radius of curvature and the particle's Larmor radius, we tested the threshold condition for strong pitch angle scattering based on the MHD magnetic field solution. The magnetic field configuration is represented by the model with high accuracy, as suggested by the high correlation coefficients and very low normalized root-mean-square errors between the observed and the modeled magnetic field. The scattering criterion, based on the values of k = Rc/ρ ratio at the crossings of magnetic field lines, associated with isotropic boundaries, with the minimum B surface, predicts a critical value of kCR ∼ 33. This means that, in the absence of other scattering mechanisms, the strong pitch angle scattering takes place whenever the Larmor radius is ∼33 times smaller than the radius of curvature of the magnetic field, as predicted by the Space Weather Modeling Framework. ©2015. American Geophysical Union. All Rights Reserved.