Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Conceptual model of diurnal cycle of low-level stratiform clouds over southern West Africa
    Lohou, Fabienne ; Kalthoff, Norbert ; Adler, Bianca ; Babić, Karmen ; Dione, Cheikh ; Lothon, Marie ; Pedruzo-Bagazgoitia, Xabier ; Zouzoua, Maurin - \ 2020
    Atmospheric Chemistry and Physics 20 (2020)4. - ISSN 1680-7316 - p. 2263 - 2275.

    The DACCIWA (Dynamics Aerosol Chemistry Cloud Interactions in West Africa) project and the associated ground-based field experiment, which took place during summer 2016, provided a comprehensive dataset on the low-level stratiform clouds (LLSCs), which develop almost every night over southern West Africa. The LLSCs, inaccurately represented in climate and weather forecasts, form in the monsoon flow during the night and break up during the following morning or afternoon, affecting considerably the radiation budget. Several published studies give an overview of the measurements during the campaign, analyse the dynamical features in which the LLSCs develop, and quantify the processes involved in the LLSC formation. Based on the main results of these studies and new analyses, we propose in this paper a conceptual model of the diurnal cycle of the LLSCs over southern West Africa. Four main phases compose the diurnal cycle of the LLSC. The stable and the jet phases are the two steps during which the relative humidity increases, due to cooling of the air, until the air is saturated and the LLSCs form. Horizontal advection of cold air from the Guinean coast by the maritime inflow and the nocturnal low-level jet (NLLJ) represents 50 % of the local total cooling. The remaining half is mainly due to divergence of net radiation and turbulence flux. The third step of the LLSC diurnal cycle is the stratus phase, which starts during the night and lasts until the onset of surface-buoyancy-driven turbulence on the following day. During the stratus phase, interactions between the LLSCs and the NLLJ lead to a modification of the wind speed vertical profile in the cloud layer, and a mixing of the sub-cloud layer by shear-driven turbulence below the NLLJ core. The breakup of the LLSC occurs during the convective phase and follows three different scenarios which depend on the intensity of the turbulence observed during the night in the sub-cloud layer. The breakup time has a considerable impact on the energy balance of the Earth's surface and, consequently, on the depth of the convective boundary layer, which could vary by a factor of 2 from day-to-day.

    The diurnal stratocumulus-to-cumulus transition over land in southern West Africa
    Pedruzo-bagazgoitia, Xabier ; Roode, Stephan R. De; Adler, Bianca ; Babić, Karmen ; Dione, Cheikh ; Kalthoff, Norbert ; Lohou, Fabienne ; Lothon, Marie ; Vilà-guerau De Arellano, Jordi - \ 2020
    Atmospheric Chemistry and Physics 20 (2020)5. - ISSN 1680-7316 - p. 2735 - 2754.
    The misrepresentation of the diurnal cycle of boundary layer clouds by large-scale models strongly impacts the modeled regional energy balance in southern West Africa. In particular, recognizing the processes involved in the maintenance and transition of the nighttime stratocumulus to diurnal shallow cumulus over land remains a challenge. This is due to the fact that over vegetation, surface fluxes exhibit a much larger magnitude and variability than on the more researched marine stratocumulus transitions. An improved understanding of the interactions between surface and atmosphere is thus necessary to improve its representation. To this end, the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) measurement campaign gathered a unique dataset of observations of the frequent stratocumulus-to-cumulus transition in southern West Africa. Inspired and constrained by these observations, we perform a series of numerical experiments using large eddy simulation. The experiments include interactive radiation and surface schemes where we explicitly resolve, quantify and describe the physical processes driving such transition. Focusing on the local processes, we quantify the transition in terms of dynamics, radiation, cloud properties, surface processes and the evolution of dynamically relevant layers such as subcloud layer, cloud layer and inversion layer. We further quantify the processes driving the stratocumulus thinning and the subsequent transition initiation by using a liquid water path budget. Finally, we study the impact of mean wind and wind shear at the cloud top through two additional numerical experiments. We find that the sequence starts with a nighttime well-mixed layer from the surface to the cloud top, in terms of temperature and humidity, and transitions to a prototypical convective boundary layer by the afternoon. We identify radiative cooling as the largest factor for the maintenance leading to a net thickening of the cloud layer of about 18 g m−2 h−1 before sunrise. Four hours after sunrise, the cloud layer decouples from the surface through a growing negative buoyancy flux at the cloud base. After sunrise, the increasing impact of entrainment leads to a progressive thinning of the cloud layer. While the effect of wind on the stratocumulus layer during nighttime is limited, after sunrise we find shear at the cloud top to have the largest impact: the local turbulence generated by shear enhances the boundary layer growth and entrainment aided by the increased surface fluxes. As a consequence, wind shear at the cloud top accelerates the breakup and transition by about 2 h. The quantification of the transition and its driving factors presented here sets the path for an improved representation by larger-scale models
    Earth System Governance : Science and Implementation Plan of the Earth System Governance Project 2018
    Burch, Sarah ; Gupta, A. ; Yumie Aoki Inoue, Christina ; Kalfagianni, Agni ; Persson, Asa ; Heijden, Jeroen van der; Vervoort, Joost ; Adler, Carolina ; Bloomfield, Michael John ; Djalante, Riyanti ; Dryzek, John S. ; Galaz, Victor ; Gordon, Christopher ; Harmon, Renee ; Jinnah, Sikina ; Kim, Rakhyun E. ; Olsson, Lennart ; Leeuwen, J. van; Ramasar, Vasna ; Wapner, Paul ; Zondervan, Ruben - \ 2019
    Utrecht : Earth System Governance - 128 p.
    Low-level stratiform clouds and dynamical features observed within the southern West African monsoon
    Dione, Cheikh ; Lohou, Fabienne ; Lothon, Marie ; Adler, Bianca ; Babić, Karmen ; Kalthoff, Norbert ; Pedruzo-Bagazgoitia, Xabier ; Bezombes, Yannick ; Gabella, Omar - \ 2019
    Atmospheric Chemistry and Physics 19 (2019)13. - ISSN 1680-7316 - p. 8979 - 8997.

    During the boreal summer, the monsoon season that takes place in West Africa is accompanied by low stratus clouds over land that stretch from the Guinean coast several hundred kilometers inland. Numerical climate and weather models need finer description and knowledge of cloud macrophysical characteristics and of the dynamical and thermodynamical structures occupying the lowest troposphere, in order to be properly evaluated in this region. The Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) field experiment, which took place in summer 2016, addresses this knowledge gap. Low-level atmospheric dynamics and stratiform low-level cloud macrophysical properties are analyzed using in situ and remote sensing measurements continuously collected from 20 June to 30 July at Savè, Benin, roughly 180 km from the coast. The macrophysical characteristics of the stratus clouds are deduced from a ceilometer, an infrared cloud camera, and cloud radar. Onset times, evolution, dissipation times, base heights, and thickness are evaluated. The data from an ultra-high-frequency (UHF) wind profiler, a microwave radiometer, and an energy balance station are used to quantify the occurrence and characteristics of the monsoon flow, the nocturnal low-level jet, and the cold air mass inflow propagating northward from the coast of the Gulf of Guinea. The results show that these dynamical structures are very regularly observed during the entire 41 d documented period. Monsoon flow is observed every day during our study period. The so-called "maritime inflow" and the nocturnal low-level jet are also systematic features in this area. According to synoptic atmospheric conditions, the maritime inflow reaches Savè around 18:00-19:00 UTC on average. This timing is correlated with the strength of the monsoon flow. This time of arrival is close to the time range of the nocturnal low-level jet settlement. As a result, these phenomena are difficult to distinguish at the Savè site. The low-level jet occurs every night, except during rain events, and is associated 65 % of the time with low stratus clouds. Stratus clouds form between 22:00 and 06:00 UTC at an elevation close to the nocturnal low-level jet core height. The cloud base height, 310±30 m above ground level (a.g.l.), is rather stationary during the night and remains below the jet core height. The cloud top height, at 640±100 m a.g.l., is typically found above the jet core. The nocturnal low-level jet, low-level stratiform clouds, monsoon flow, and maritime inflow reveal significant day-to-day and intra-seasonal variability during the summer given the importance of the different monsoon phases and synoptic atmospheric conditions. Distributions of strength, depth, onset time, breakup time, etc. are quantified here. These results contribute to satisfy the main goals of DACCIWA and allow a conceptual model of the dynamical structures in the lowest troposphere over the southern part of West Africa.

    New directions in earth system governance research
    Burch, Sarah ; Gupta, A. ; Inoue, C. ; Kalfagianni, Agni ; Persson, Asa ; Gerlak, Andrea K. ; Ishii, Atsushi ; Patterson, James ; Pickering, Jonathan ; Scobie, M. ; Heijden, Jeroen van der; Vervoort, J. ; Adler, Carolina ; Bloomfield, Michael ; Djalante, Riyante ; Dryzek, John ; Galaz, Victor ; Gordon, Christopher ; Harmon, Renée ; Jinnah, Sikina ; Kim, Rakhyun E. ; Olsson, Lennart ; Leeuwen, J. van; Ramasar, Vasna ; Wapner, Paul ; Zondervan, R. - \ 2019
    Earth System Governance 1 (2019). - ISSN 2589-8116 - 18 p.
    Governance - Research networks - Earth system - Transformation
    The Earth System Governance project is a global research alliance that explores novel, effective governance mechanisms to cope with the current transitions in the biogeochemical systems of the planet. A decade after its inception, this article offers an overview of the project's new research framework (which is built upon a review of existing earth system governance research), the goal of which is to continue to stimulate a pluralistic, vibrant and relevant research community. This framework is composed of contextual conditions (transformations, inequality, Anthropocene and diversity), which capture what is being observed empirically, and five sets of research lenses (architecture and agency, democracy and power, justice and allocation, anticipation and imagination, and adaptiveness and reflexivity). Ultimately the goal is to guide and inspire the systematic study of how societies prepare for accelerated climate change and wider earth system change, as well as policy responses.
    The observed diurnal cycle of low-level stratus clouds over southern West Africa : A case study
    Babić, Karmen ; Adler, Bianca ; Kalthoff, Norbert ; Andersen, Hendrik ; Dione, Cheikh ; Lohou, Fabienne ; Lothon, Marie ; Pedruzo-Bagazgoitia, Xabier - \ 2019
    Atmospheric Chemistry and Physics 19 (2019)2. - ISSN 1680-7316 - p. 1281 - 1299.

    This study presents the first detailed observational analysis of the complete diurnal cycle of stratiform low-level clouds (LLC) and involved atmospheric processes over southern West Africa (SWA). The data used here were collected during the comprehensive DACCIWA (Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa) ground-based campaign, which aimed at monitoring LLC characteristics and capturing the wide range of atmospheric conditions related to theWest African monsoon flow. In this study, in situ and remote sensing measurements from the supersite near Savè (Benin) collected during a typical day, which is characterized by the onset of a nocturnal lowlevel jet (NLLJ) and the formation of LLC, are analyzed. The associated dynamic and thermodynamic conditions allow the identification of five different phases related to the LLC diurnal cycle: the stable, jet, stratus I, stratus II, and convective phases. The analysis of relative humidity tendency shows that cooling is a dominant process for LLC formation, which leads to a continuous increase in relative humidity at a maximum rate of 6%h-1, until finally saturation is reached and LLC form with a cloud-base height near the height of NLLJ maximum. Results of heat budget analysis illustrate that horizontal cold-air advection, related to the maritime inflow, which brings the cool maritime air mass and a prominent NLLJ wind profile, has the dominant role in the observed strong cooling of-1.2Kh-1 during the jet phase. The contribution from horizontal cold advection is quantified to be up to 68 %, while radiative cooling and sensible heat flux divergence both contribute 16% to the observed heat budget below the NLLJ maximum. After the LLC form (stratus phases I and II), turbulent mixing is an important factor leading to the cooling below the cloud base, while strong radiative cooling at the cloud top helps to maintain thick stratus.

    Nocturnal low-level clouds in the atmospheric boundary layer over southern West Africa : an observation-based analysis of conditions and processes
    Adler, Bianca ; Babia, Karmen ; Kalthoff, Norbert ; Lohou, Fabienne ; Lothon, Marie ; Dione, Cheikh ; Pedruzo-Bagazgoitia, Xabier ; Andersen, Hendrik - \ 2019
    Atmospheric Chemistry and Physics 19 (2019)1. - ISSN 1680-7316 - p. 663 - 681.
    During the West African summer monsoon season, extended nocturnal stratiform low-level clouds (LLCs) frequently form in the atmospheric boundary layer over southern West Africa and persist long into the following day affecting the regional climate. A unique data set was gathered within the framework of the Dynamics-Aerosol- Chemistry-Cloud Interactions in West Africa (DACCIWA) project, which allows, for the first time, for an observational analysis of the processes and parameters crucial for LLC formation. In this study, in situ and remote sensing measurements from radiosondes, ceilometer, cloud radar and energy balance stations from a measurement site near Save in Benin are analyzed amongst others for 11 nights. The aim is to study LLC characteristics, the intranight variability of boundary layer conditions and physical processes relevant for LLC formation, as well as to assess the importance of these processes. Based on the dynamic and thermodynamic conditions in the atmospheric boundary layer we distinguish typical nocturnal phases and calculate mean profiles for the individual phases. A stable surface inversion, which forms after sunset, is eroded by differential horizontal cold air advection with the Gulf of Guinea maritime inflow, a cool air mass propagating northwards from the coast in the late afternoon and the evening, and shear-generated turbulence related to a nocturnal low-level jet. The analysis of the contributions to the relative humidity changes before the LLC formation reveals that cooling in the atmospheric boundary layer is crucial to reach saturation, while specific humidity changes play a minor role.We quantify the heat budget terms and find that about 50% of the cooling prior to LLC formation is caused by horizontal cold air advection, roughly 20% by radiative flux divergence and about 22% by sensible heat flux divergence in the presence of a low-level jet. The outcomes of this study contribute to the development of a conceptual model on LLC formation, maintenance and dissolution over southern West Africa.
    Breeding progress and preparedness for mass-scale deployment of perennial lignocellulosic biomass crops switchgrass, miscanthus, willow and poplar
    Clifton-Brown, John ; Harfouche, Antoine ; Casler, Michael D. ; Dylan Jones, Huw ; Macalpine, William J. ; Murphy-Bokern, Donal ; Smart, Lawrence B. ; Adler, Anneli ; Ashman, Chris ; Awty-Carroll, Danny ; Bastien, Catherine ; Bopper, Sebastian ; Botnari, Vasile ; Brancourt-Hulmel, Maryse ; Chen, Zhiyong ; Clark, Lindsay V. ; Cosentino, Salvatore ; Dalton, Sue ; Davey, Chris ; Dolstra, Oene ; Donnison, Iain ; Flavell, Richard ; Greef, Joerg ; Hanley, Steve ; Hastings, Astley ; Hertzberg, Magnus ; Hsu, Tsai Wen ; Huang, Lin S. ; Iurato, Antonella ; Jensen, Elaine ; Jin, Xiaoli ; Jørgensen, Uffe ; Kiesel, Andreas ; Kim, Do Soon ; Liu, Jianxiu ; McCalmont, Jon P. ; McMahon, Bernard G. ; Mos, Michal ; Robson, Paul ; Sacks, Erik J. ; Sandu, Anatolii ; Scalici, Giovanni ; Schwarz, Kai ; Scordia, Danilo ; Shafiei, Reza ; Shield, Ian ; Slavov, Gancho ; Stanton, Brian J. ; Swaminathan, Kankshita ; Trindade, Luisa M. - \ 2019
    Global change biology Bioenergy 11 (2019)1. - ISSN 1757-1693 - p. 118 - 151.
    bioenergy - feedstocks - lignocellulose - M. sacchariflorus - M. sinensis - Miscanthus - Panicum virgatum - perennial biomass crop - Populus spp. - Salix spp.

    Genetic improvement through breeding is one of the key approaches to increasing biomass supply. This paper documents the breeding progress to date for four perennial biomass crops (PBCs) that have high output–input energy ratios: namely Panicum virgatum (switchgrass), species of the genera Miscanthus (miscanthus), Salix (willow) and Populus (poplar). For each crop, we report on the size of germplasm collections, the efforts to date to phenotype and genotype, the diversity available for breeding and on the scale of breeding work as indicated by number of attempted crosses. We also report on the development of faster and more precise breeding using molecular breeding techniques. Poplar is the model tree for genetic studies and is furthest ahead in terms of biological knowledge and genetic resources. Linkage maps, transgenesis and genome editing methods are now being used in commercially focused poplar breeding. These are in development in switchgrass, miscanthus and willow generating large genetic and phenotypic data sets requiring concomitant efforts in informatics to create summaries that can be accessed and used by practical breeders. Cultivars of switchgrass and miscanthus can be seed-based synthetic populations, semihybrids or clones. Willow and poplar cultivars are commercially deployed as clones. At local and regional level, the most advanced cultivars in each crop are at technology readiness levels which could be scaled to planting rates of thousands of hectares per year in about 5 years with existing commercial developers. Investment in further development of better cultivars is subject to current market failure and the long breeding cycles. We conclude that sustained public investment in breeding plays a key role in delivering future mass-scale deployment of PBCs.

    Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
    Karp, Daniel S. ; Chaplin-Kramer, Rebecca ; Meehan, Timothy D. ; Martin, Emily A. ; Declerck, Fabrice ; Grab, Heather ; Gratton, Claudio ; Hunt, Lauren ; Larsen, Ashley E. ; Martínez-Salinas, Alejandra ; O’Rourke, Megan E. ; Rusch, Adrien ; Poveda, Katja ; Jonsson, Mattias ; Rosenheim, Jay A. ; Schellhorn, Nancy A. ; Tscharntke, Teja ; Wratten, Stephen D. ; Zhang, Wei ; Iverson, Aaron L. ; Adler, Lynn S. ; Albrecht, Matthias ; Alignier, Audrey ; Angelella, Gina M. ; Zubair Anjum, Muhammad ; Avelino, Jacques ; Batáry, Péter ; Baveco, Johannes M. ; Bianchi, Felix J.J.A. ; Birkhofer, Klaus ; Bohnenblust, Eric W. ; Bommarco, Riccardo ; Brewer, Michael J. ; Caballero-López, Berta ; Carrière, Yves ; Carvalheiro, Luísa G. ; Cayuela, Luis ; Centrella, Mary ; Ćetković, Aleksandar ; Henri, Dominic Charles ; Chabert, Ariane ; Costamagna, Alejandro C. ; La Mora, Aldo De; Kraker, Joop De; Desneux, Nicolas ; Diehl, Eva ; Diekötter, Tim ; Dormann, Carsten F. ; Eckberg, James O. ; Entling, Martin H. ; Fiedler, Daniela ; Franck, Pierre ; Veen, F.J.F. van; Frank, Thomas ; Gagic, Vesna ; Garratt, Michael P.D. ; Getachew, Awraris ; Gonthier, David J. ; Goodell, Peter B. ; Graziosi, Ignazio ; Groves, Russell L. ; Gurr, Geoff M. ; Hajian-Forooshani, Zachary ; Heimpel, George E. ; Herrmann, John D. ; Huseth, Anders S. ; Inclán, Diego J. ; Ingrao, Adam J. ; Iv, Phirun ; Jacot, Katja ; Johnson, Gregg A. ; Jones, Laura ; Kaiser, Marina ; Kaser, Joe M. ; Keasar, Tamar ; Kim, Tania N. ; Kishinevsky, Miriam ; Landis, Douglas A. ; Lavandero, Blas ; Lavigne, Claire ; Ralec, Anne Le; Lemessa, Debissa ; Letourneau, Deborah K. ; Liere, Heidi ; Lu, Yanhui ; Lubin, Yael ; Luttermoser, Tim ; Maas, Bea ; Mace, Kevi ; Madeira, Filipe ; Mader, Viktoria ; Cortesero, Anne Marie ; Marini, Lorenzo ; Martinez, Eliana ; Martinson, Holly M. ; Menozzi, Philippe ; Mitchell, Matthew G.E. ; Miyashita, Tadashi ; Molina, Gonzalo A.R. ; Molina-Montenegro, Marco A. ; O’Neal, Matthew E. ; Opatovsky, Itai ; Ortiz-Martinez, Sebaastian ; Nash, Michael ; Östman, Örjan ; Ouin, Annie ; Pak, Damie ; Paredes, Daniel ; Parsa, Soroush ; Parry, Hazel ; Perez-Alvarez, Ricardo ; Perović, David J. ; Peterson, Julie A. ; Petit, Sandrine ; Philpott, Stacy M. ; Plantegenest, Manuel ; Plećaš, Milan ; Pluess, Therese ; Pons, Xavier ; Potts, Simon G. ; Pywell, Richard F. ; Ragsdale, David W. ; Rand, Tatyana A. ; Raymond, Lucie ; Ricci, Benoît ; Sargent, Chris ; Sarthou, Jean-Pierre ; Saulais, Julia ; Schäckermann, Jessica ; Schmidt, Nick P. ; Schneider, Gudrun ; Schüepp, Christof ; Sivakoff, Frances S. ; Smith, Henrik G. ; Stack Whitney, Kaitlin ; Stutz, Sonja ; Szendrei, Zsofia ; Takada, Mayura B. ; Taki, Hisatomo ; Tamburini, Giovanni ; Thomson, Linda J. ; Tricault, Yann ; Tsafack, Noelline ; Tschumi, Matthias ; Valantin-Morison, Muriel ; Trinh, Mai Van; Werf, Wopke Van Der; Vierling, Kerri T. ; Werling, Ben P. ; Wickens, Jennifer B. ; Wickens, Victoria J. ; Woodcock, Ben A. ; Wyckhuys, Kris ; Xiao, Haijun ; Yasuda, Mika ; Yoshioka, Akira - \ 2018
    Proceedings of the National Academy of Sciences of the United States of America 115 (2018)33. - ISSN 0027-8424 - p. E7863 - E7870.
    IPM
    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
    A global network for operational flood risk reduction
    Alfieri, Lorenzo ; Cohen, Sagy ; Galantowicz, John ; Schumann, Guy J.P. ; Trigg, Mark A. ; Zsoter, Ervin ; Prudhomme, Christel ; Kruczkiewicz, Andrew ; Coughlan de Perez, Erin ; Flamig, Zachary ; Rudari, Roberto ; Wu, Huan ; Adler, Robert F. ; Brakenridge, Robert G. ; Kettner, Albert ; Weerts, Albrecht ; Matgen, Patrick ; Islam, Saiful A.K.M. ; Groeve, Tom de; Salamon, Peter - \ 2018
    Environmental Science & Policy 84 (2018). - ISSN 1462-9011 - p. 149 - 158.
    Disaster risk management - Early warning systems - Flood monitoring - Global flood partnership (GFP) - Satellite remote sensing
    Every year riverine flooding affects millions of people in developing countries, due to the large population exposure in the floodplains and the lack of adequate flood protection measures. Preparedness and monitoring are effective ways to reduce flood risk. State-of-the-art technologies relying on satellite remote sensing as well as numerical hydrological and weather predictions can detect and monitor severe flood events at a global scale. This paper describes the emerging role of the Global Flood Partnership (GFP), a global network of scientists, users, private and public organizations active in global flood risk management. Currently, a number of GFP member institutes regularly share results from their experimental products, developed to predict and monitor where and when flooding is taking place in near real-time. GFP flood products have already been used on several occasions by national environmental agencies and humanitarian organizations to support emergency operations and to reduce the overall socio-economic impacts of disasters. This paper describes a range of global flood products developed by GFP partners, and how these provide complementary information to support and improve current global flood risk management for large scale catastrophes. We also discuss existing challenges and ways forward to turn current experimental products into an integrated flood risk management platform to improve rapid access to flood information and increase resilience to flood events at global scale.
    An overview of the diurnal cycle of the atmospheric boundary layer during the West African monsoon season : Results from the 2016 observational campaign
    Kalthoff, Norbert ; Lohou, Fabienne ; Brooks, Barbara ; Jegede, Gbenga ; Adler, Bianca ; Babić, Karmen ; DIone, Cheikh ; Ajao, Adewale ; Amekudzi, Leonard K. ; Aryee, Jeffrey N.A. ; Ayoola, Muritala ; Bessardon, Geoffrey ; Danuor, Sylvester K. ; Handwerker, Jan ; Kohler, Martin ; Lothon, Marie ; Pedruzo-Bagazgoitia, Xabier ; Smith, Victoria ; Sunmonu, Lukman ; Wieser, Andreas ; Fink, Andreas H. ; Knippertz, Peter - \ 2018
    Atmospheric Chemistry and Physics 18 (2018)4. - ISSN 1680-7316 - p. 2913 - 2928.
    A ground-based field campaign was conducted in southern West Africa from mid-June to the end of July 2016 within the framework of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project. It aimed to provide a high-quality comprehensive data set for process studies, in particular of interactions between low-level clouds (LLCs) and boundary-layer conditions. In this region missing observations are still a major issue. During the campaign, extensive remote sensing and in situ measurements were conducted at three supersites: Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). Daily radiosoundings were performed at 06:00 UTC, and 15 intensive observation periods (IOPs) were performed during which additional radiosondes were launched, and remotely piloted aerial systems were operated. Extended stratiform LLCs form frequently in southern West Africa during the nighttime and persist long into the following day. They affect the radiation budget and hence the evolution of the atmospheric boundary layer and regional climate. The relevant parameters and processes governing the formation and dissolution of the LLCs are still not fully understood. This paper gives an overview of the diurnal cycles of the energy-balance components, near-surface temperature, humidity, wind speed and direction as well as of the conditions (LLCs, low-level jet) in the boundary layer at the supersites and relates them to synoptic-scale conditions (monsoon layer, harmattan layer, African easterly jet, tropospheric stratification) in the DACCIWA operational area. The characteristics of LLCs vary considerably from day to day, including a few almost cloud-free nights. During cloudy nights we found large differences in the LLCs' formation and dissolution times as well as in the cloud-base height. The differences exist at individual sites and also between the sites. The synoptic conditions are characterized by a monsoon layer with south-westerly winds, on average about 1.9 km deep, and easterly winds above; the depth and strength of the monsoon flow show great day-to-day variability. Within the monsoon layer, a nocturnal low-level jet forms in approximately the same layer as the LLC. Its strength and duration is highly variable from night to night. This unique data set will allow us to test some new hypotheses about the processes involved in the development of LLCs and their interaction with the boundary layer and can also be used for model evaluation.
    Proposal for a "standard' field study for the evaluation of the effects of parasiticides on dung and soil organisms
    Lahr, J. ; Adler, N. ; J., Bachmann ; Blanckenhorn, W.U. ; Düring, R.A. ; Floate, K.D. ; Rombke, J. ; Lumaret, J.P. ; Jensen, J. - \ 2017
    Proposal for a "standard' field study for the evaluation of the effects of parasiticides on dung and soil organisms
    Lahr, J. ; Adler, N. ; J., Bachmann ; Blanckenhorn, W.U. ; Düring, R.A. ; Floate, K.D. ; Römbke, J. ; Lumaret, J.P. ; Jensen, J. - \ 2017
    Proposal for a 'standard' field study for the evaluation of the effects of parasiticides on dung and soil organisms
    Lahr, J. ; Adler, N. ; J., Bachmann ; Blanckenhorn, W.U. ; Düring, R.A. ; Floate, K.D. ; Römbke, J. ; Tixier, T. ; Lumaret, J.P. ; Jensen, J. - \ 2017
    Numerous published studies and most authorisation procedures of parasiticidal products have shown that simple laboratory studies typically demonstrate a risk for dung fauna and/or soil dwelling invertebrates. Hence, there is a need for a more advanced standard test in order to evaluate risk under more realistic field conditions. In order to develop and validate such a field test, comparable investigations were conducted under varying conditions at Lethbridge (Canada), Montpellier (France), Zurich (Switzerland), and Wageningen (the Netherlands). Results of this project were published in 2016 in a series of articles in Environmental Toxicology and Chemistry vol. 35(8):1914-1977. This poster presents some of the lessons learned and recommendations from a methodological point of view.
    Marine mammals and windfarms: Effects of alpha ventus on harbour porpoises
    Dähne, Michael ; Peschko, Verena ; Gilles, Anita ; Lucke, Klaus ; Adler, Sven ; Ronnenberg, Katrin ; Siebert, Ursula - \ 2014
    In: Ecological Research at the Offshore Windfarm alpha ventus Springer Fachmedien Wiesbaden - ISBN 9783658024611 - p. 133 - 149.
    Offshore windfarms have the potential to affect marine mammal populations. For harbour porpoises, the threat considered most important is the influence of noise during the construction phase. Effects of the operational period that need to be considered can be either noise effects or effects due to alteration to the habitat where foundations were erected. Visual surveys and stationary acoustic monitoring showed a strong avoidance reaction during pile-driving while during the operational period results were inconclusive. In future, these impacts must be seen in a larger framework to predict the biological significance of cumulative effects
    Improving the supply chain and food quality of professionally prepared meals
    Adler-Nissen, Jens ; Akkerman, Renzo ; Frosch, Stina ; Grunow, Martin ; Løje, Hanne ; Risum, Jørgen ; Wang, Yang ; Ørnholt-Johansson, Gine - \ 2013
    Trends in Food Science and Technology 29 (2013)1. - ISSN 0924-2244 - p. 74 - 79.

    An increasing share of the daily meals served in Europe is prepared out-of-home by professionals in foodservice. The quality of such meals is highly debated. This paper presents and discusses obstacles to improving quality in a cost-effective way and suggests solutions: 1) Modularisation of the meal production in order to transfer labour-intensive operations from the kitchens to the industry; 2) Systemic use of a new concept: thawing during distribution, which improves shelf-life and reduces waste; 3) Supply chain modelling to improve delivery schedules and reduce environmental impact. Existing food legislation complies with the suggested approaches.

    Effects of pile-driving on harbour porpoises (Phocoena phocoena) at the first offshore wind farm in Germany
    Daehne, M. ; Gilles, A. ; Lucke, K. ; Peschko, V. ; Adler, S. ; Kruegel, K. ; Sundermeyer, J. ; Siebert, U. - \ 2013
    Environmental Research Letters 8 (2013)2. - ISSN 1748-9326
    air bubble curtain - north-sea - underwater noise - aerial surveys - baltic sea - detection thresholds - marine mammals - t-pods - waters - abundance
    The first offshore wind farm 'alpha ventus' in the German North Sea was constructed north east of Borkum Reef Ground approximately 45 km north off the German coast in 2008 and 2009 using percussive piling for the foundations of 12 wind turbines. Visual monitoring of harbour porpoises was conducted prior to as well as during construction and operation by means of 15 aerial line transect distance sampling surveys, from 2008 to 2010. Static acoustic monitoring (SAM) with echolocation click loggers at 12 positions was performed additionally from 2008 to 2011. SAM devices were deployed between 1 and 50 km from the centre of the wind farm. During aerial surveys, 18¿600 km of transect lines were covered in two survey areas (10¿934 and 11¿824 km2) and 1392 harbour porpoise sightings were recorded. Lowest densities were documented during the construction period in 2009. The spatial distribution pattern recorded on two aerial surveys three weeks before and exactly during pile-driving points towards a strong avoidance response within 20 km distance of the noise source. Generalized additive modelling of SAM data showed a negative impact of pile-driving on relative porpoise detection rates at eight positions at distances less than 10.8 km. Increased detection rates were found at two positions at 25 and 50 km distance suggesting that porpoises were displaced towards these positions. A pile-driving related behavioural reaction could thus be detected using SAM at a much larger distance than a pure avoidance radius would suggest. The first waiting time (interval between porpoise detections of at least 10 min), after piling started, increased with longer piling durations. A gradient in avoidance, a gradual fading of the avoidance reaction with increasing distance from the piling site, is hence most probably a product of an incomplete displacement during shorter piling events.
    Modelling harbour porpoise seasonal density as a function of the German Bight environment: implications for management
    Gilles, A. ; Adler, S. ; Kaschner, K. ; Scheidat, M. ; Siebert, U. - \ 2011
    Endangered Species Research 14 (2011)2. - ISSN 1863-5407 - p. 157 - 169.
    A classical user–environment conflict could arise between the recent expansion plans of offshore wind power in European waters and the protection of the harbour porpoise Phocoena phocoena, an important top predator and indicator species in the North Sea. There is a growing demand for predictive models of porpoise distribution to assess the extent of potential conflicts and to support conservation and management plans. Here, we used a range of oceanographic parameters and generalised additive models to predict harbour porpoise density and to investigate seasonal shifts in porpoise distribution in relation to several static and dynamic predictors. Sightings were collected during dedicated line-transect aerial surveys conducted year-round between 2002 and 2005. Over the 4 yr, survey effort amounted to 38720 km, during which 3887 harbour porpoises were sighted. Porpoises aggregated in distinct hot spots within their seasonal range, but the importance of key habitat descriptors varied between seasons. Predictors explaining most of the variance were the hydrographical parameter ‘residual current’ and proxies for primary production and fronts (chlorophyll and nutrients) as well as the interaction ‘distance to coast/water depth’. Porpoises preferred areas with stronger currents and concentrated in areas where fronts are likely. Internal cross-validation indicated that all models were highly robust. In addition, we successfully externally validated our summer model using an independent data set, which allowed us to extrapolate our predictions to a more regional scale. Our models improve the understanding of determinants of harbour porpoise habitat in the North Sea as a whole and inform management frameworks to determine safe limits of anthropogenic impacts
    Global patterns of leaf mechanical properties
    Onoda, Y. ; Westoby, M. ; Adler, N.E. ; Choong, A.M.L. ; Clissold, F.J. ; Cornelissen, J.H.C. ; Diaz, S. ; Dominy, N.J. ; Elgart, A. ; Markesteijn, L. ; Poorter, L. ; Kitajima, K. - \ 2011
    Ecology Letters 14 (2011)3. - ISSN 1461-023X - p. 301 - 312.
    fracture-toughness - life-span - latitudinal variation - economics spectrum - leaves - plants - traits - shade - photosynthesis - biomechanics
    Leaf mechanical properties strongly influence leaf lifespan, plant-herbivore interactions, litter decomposition and nutrient cycling, but global patterns in their interspecific variation and underlying mechanisms remain poorly understood. We synthesize data across the three major measurement methods, permitting the first global analyses of leaf mechanics and associated traits, for 2819 species from 90 sites worldwide. Key measures of leaf mechanical resistance varied c. 500-800-fold among species. Contrary to a long-standing hypothesis, tropical leaves were not mechanically more resistant than temperate leaves. Leaf mechanical resistance was modestly related to rainfall and local light environment. By partitioning leaf mechanical resistance into three different components we discovered that toughness per density contributed a surprisingly large fraction to variation in mechanical resistance, larger than the fractions contributed by lamina thickness and tissue density. Higher toughness per density was associated with long leaf lifespan especially in forest understory. Seldom appreciated in the past, toughness per density is a key factor in leaf mechanical resistance, which itself influences plant-animal interactions and ecosystem functions across the globe
    Phytophthora andina sp nov., a newly identified heterothallic pathogen of solanaceous hosts in the Andean highlands
    Oliva, R.F. ; Kroon, L.P.N.M. ; Chacon, G. ; Flier, W.G. ; Ristaino, J.B. ; Forbes, G.A. - \ 2010
    Plant Pathology 59 (2010)4. - ISSN 0032-0862 - p. 613 - 625.
    infestans-sensu-lato - central mexico - toluca valley - phylogenetic-relationships - genetic analyses - wild solanum - ecuador - potato - mitochondrial - populations
    A blight disease on fruits and foliage of wild and cultivated Solanum spp. was found to be associated with a new species of Phytophthora. The proposed novel species is named Phytophthora andina Adler & Flier, sp. nov. based on morphological characteristics, pathogenicity assays, mitochondrial DNA haplotyping, AFLP fingerprinting and nuclear and mitochondrial DNA sequence analyses. Isolates of P. andina (n = 48) from the Andean highland tropics of Ecuador were collected from 1995 to 2006. Phytophothora andina is closely related to P. infestans and has semipapillate, ellipsoidal sporangia borne on sympodially branched sporangiophores. It is heterothallic and produces amphigynous antheridia. The species consists of several clonal lineages, including the EC-2 and EC-3 RFLP lineages, which were described previously as P. infestans. Approximately 75% of isolates react as compatibility type A2 when paired with an A1 compatibility type isolate of P. infestans. However, when A2 isolates from the Anarrhichomenum section of Solanum were paired in all combinations, viable oospores were obtained in several crosses, suggesting that there is a unique compatibility interaction in P. andina that is complementary to that described in P. infestans. Nuclear and mitochondrial sequence analysis supported the species designation of P. andina. This newly identified heterothallic pathogen shares a common ancestor with P. infestans and may have arisen from hybridization events with sister taxa in the Andes.
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