bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant phosphorus use and acquisition strategies in the Amazon rainforest with relevance to vegetation models
Authors: Reichert Tatiana , Rammig Anja , A. Quesada Carlos , Fuchslueger Lucia , F. Lugli Laynara , Fleischer Katrin
Published: March 2020

The Amazon rainforest is the biggest tropical rainforest in the world and provides significant global climate regulation services. However, the future of the Amazon rainforest carbon sink under elevated CO2 is uncertain. The potential fertilization effect of elevated CO2 on the Amazon rainforest carbon sink may be constrained by phosphorus availability. Phosphorus is an essential element involved in all major plant processes and is considered to be the primary limiting nutrient in the Amazon rainforest. To cope with phosphorus limitation, plants have developed different strategies to increase the use efficiency, uptake, and availability of phosphorus. Vegetation models have identified phosphorus use and acquisition strategies as crucial to the projections of the future of the Amazon rainforest. Although some of the strategies are explicitly or implicitly represented in vegetation models, the mechanistic representations diverge due to the lack of empirical knowledge. Here, we synthesized the current understanding of the main strategies and how they may play out in the Amazon rainforest, namely, root phosphorus foraging, arbuscular mycorrhizal symbiosis, phosphatase and organic acids exudation, and leaf phosphorus resorption. We focus on mechanisms, drivers, and plasticity along soil phosphorus gradients of the named strategies, aiming to inform models and highlight important knowledge gaps, offering an opportunity to bring modeling and experimental research together.
Tell me what's underneath! Using a model to investigate core sampling methodology with secondary school students
Authors: Borghini Alessandra
Published: March 2020

What is under our feet? How can we study something that we cannot directly see? How can we reconstruct Earth’s history?
To find answers to these interesting questions scientists developed different methodologies to investigate soil, rock formations, as well as the deeper structure of Earth’s interior. The same questions can be used as a starting point for many teaching activities.
In the teaching activity we experimented with 11-12 years old students in a Secondary School in Italy, we used a model made with inexpensive materials to discover core sampling, one of the methodologies used by geologists to investigate the outermost part of our planet and gather important information to reconstruct Earth’s history. 
One of the aims of the teaching sequence is to make students understand the work of geologists and how they can discover what happened in the past by studying rocks. These activities are also a way to help students to develop important skills such as formulating hypotheses, carrying on investigations and using data to validate a hypothesis.
In this poster I present the activities and discuss some observations on students' drawings and descriptions, collected during the learning sequence to better understand students’ learning process and the learning outcomes. 

 
Modeling the transition of death assemblages from surface to subsurface: predicting the effects of burial, mixing, and disintegration on time averaging
Authors: Tomašových Adam , Kidwell Susan M. , Dai Ran
Published: March 2020

Although the temporal resolution and incompleteness of the fossil record are strongly determined by the thickness of the taphonomic active zone and by the depth and rate of mixing, it is unclear whether changes in time-averaging associated with the burial of assemblages that form in the surface mixed layer (SML) can be generalized across environments. Here we extend our previous models, which estimated disintegration on the basis of shell-age distributions (AFDs) in the SML, to stochastic transition matrices, and then apply them to discrete stratigraphic layers in sediment cores. This permits us to: (1) predict downcore trends in the shape of shell AFDs, and (2) estimate burial, disintegration, and mixing rates on the basis of age distributions observed in sediment cores. We find that, first, if the time to burial of individual shells to a specific sediment depth is stochastic due to bioturbation, then the inter-quartile age range will increase and skewness and kurtosis will decrease downcore to the top of permanent, historical layers (because the deepest layers reached by bioturbators are affected by mixing for a longer time than are surface layers). Systematic dm- to meter-scale changes in AFDs downcore can thus arise without changes in rates of sedimentation or mixing. Second, in contrast to expectations that species with durable shells will exhibit greater time averaging (larger inter-quartile age ranges) than species with fragile shells (an effect typical of assemblages in the SML), this difference will be minimized below the taphonomically active zone. Third, the median and modes of the AFDs of species differing in durability will differ, however, in those subsurface assemblages, producing age offsets (geologic age discordance) among species. These three predictions are clearly relevant for Holocene-Anthropocene studies, but also inform our understanding of deeper time fossil records, where episodically rapid burial can move surface assemblage to historical layers. In such case, the downcore decline in time averaging associated predicted by the surface-subsurface transition will characterize some subsets of stratigraphic successions in the fossil record.
Geostructural complexity and passive seismic surveys: a geostatistical analysis in the Kathmandu basin
Authors: Trevisani Sebastiano , Maharian Dev Kumar , Sandron Denis , Shrestha Surya Narayan , Paudyal Sarmila , Pettenati Franco , Giorgi Massimo
Published: March 2020

In this study a set of 39 single station passive seismic surveys conducted in the Kathmandu basin (Nepal), based on the horizontal to vertical spectral ratio methodology (HVSR), is analyzed by means of a geostatistical approach. The Kathmandu basin is characterized by a heterogeneous sedimentary cover and by a complex geostructural setting, inducing high spatial variability of the bedrock depth. In relation to the complex geological setting, the interpretation and analysis of HVSR data are challenging, both from the perspective of bedrock depth analysis as well as of seismic site effects detection. In order to maximize the broad range of information available, the HVSR data are analyzed according to a geostatistical approach. First, the spatial continuity structure of HVSR data is analyzed and interpreted taking into consideration the geological setting and available stratigraphic and seismic information. In addition, we test the possibility to integrate the analysis with potential auxiliary variables, derived from geomorphometric variables and considering the distance from outcropping bedrock. The explorative geostatistical analysis confirms the complexity of the geo-structural setting of the area. Finally, a mapping of HVSR resonance periods, with the evaluation of interpolation uncertainty, is obtained by means of ordinary kriging interpolation. The resulting map, even if characterized by a large interpolation support, is congruent with the geo-structural setting and the main lineaments of the area. The adopted approach is particularly useful in the context of micro-zonation studies based on HVSR methodology conducted in historical urban areas. Moreover, this work contributes to the geo-structural knowledge of the deep structure of the Kathmandu basin.

References

Paudyal YR, Yatabe R, Bhandary NP, Dahal RK, 2013. Basement topography of the Kathmandu Basin using microtremor observation. J Asian Earth Sci 62:627–637, doi.org/10.1016/j.jseaes.2012.11.011.

Nakamura Y., 1989. A method for dynamic characteristic estimation of subsurface using microtremors on the ground surface. Quart. Rep. Railway Tech. Res. Inst. 30, 25-33

Sandron D., S. .Maskey , M. Giorgi, D. V. Maharjan, S. N. Narayan, C. Cravos, F. Pettenati, 2019. Environmental and on buildings noise measures: Laliptur (Kathmandu). Earthquake Engineering. Vol. 60, n. 1, 17-38: March 2019, doi 10.4430/bgta0259.

Trevisani S., Boaga J., Agostini L., Galgaro A., 2017. Insights into bedrock surface morphology using low-cost passive seismic surveys and integrated geostatistical analysis. Science of the Total Environment, 578, 186-202, http://dx.doi.org/ 10.1016/j.scitotenv.2016.11.041.
Propagation of Freshwater Lenses as Buoyant Gravity Currents
Authors: Moulin Aurélie , Moum James , Shroyer Emily
Published: March 2020

Freshwater lenses (FWL) deposited by rain create surface salinity and temperature anomalies that can persist for extended periods of time (> 1 day). The resulting patchiness in near-surface density and sea surface temperature influence upper ocean dynamics and air-sea fluxes of heat. For these reasons, understanding lens formation and evolution has been a focus of recent observational and modeling efforts. The work presented here integrates near-surface ocean and atmosphere time series with remote sensing of sea surface roughness (X-band radar) and precipitation (C-band radar) to describe the formation and temporal evolution of lenses within the equatorial Indian Ocean. Twenty-six FWLs are observed at different stages of their evolution from freshly deposited and actively spreading to older, passively advected features. Salinity anomalies reached -1.2 psu near the surface, while temperature anomalies were observed to be both cool (down to -0.8°C) and warm (up to +0.4°C). The largest density anomaly reached -0.5 kg/m3. Remotely-sensed, ship-based radar imagery allows for quantification of the observed propagation speeds of ten lenses, which follow internal gravity wave theory. These results offer a novel perspective on the evolution of FWLs whose dynamics need to be properly accounted for to assess lens longevity, including persistence of salinity and temperature anomalies, as well as influences to air-sea interactions.
The additional value of using proxy data besides runoff for calibrating a conceptual hydrological model in a small agricultural catchment
Authors: Széles Borbála , Parajka Juraj , Hogan Patrick , Silasari Rasmiaditya , Pavlin Lovrenc , Strauss Peter , Blöschl Günter
Published: March 2020

The aim of this study was to explore the additional value of using proxy data besides runoff for calibrating a conceptual hydrological model. The study area was the Hydrological Open Air Laboratory (HOAL), a 66 ha large experimental catchment in Austria. A conceptual, HBV type, spatially lumped hydrological model was calibrated following two approaches. First, the model was calibrated in one step using only runoff data. Second, we proposed a step-by-step approach, where the modules of the model (snow, soil moisture and runoff generation) were calibrated using proxy data besides runoff, such as snow, actual evapotranspiration, soil moisture, overland flow and groundwater level. The two approaches were evaluated on annual, seasonal and daily time scales. Using the proposed step-by-step approach, the runoff volume errors in the calibration and validation periods were 0% and -1%, the monthly Pearson correlation coefficients were 0.92 and 0.82, and the daily logarithmic Nash Sutcliffe efficiencies were 0.59 and 0.18, respectively. The additional benefit of using proxy data besides runoff was the improved overall process consistency compared to the approach when only runoff was used for model calibration. Soil moisture and evapotranspiration observations had the largest influence on simulated runoff, while the calibration of the snow and runoff generation modules had a smaller influence.
Multiyear predictability of extratropical North Atlantic sea surface temperatures in hindcasts initialized with wind stress anomalies
Authors: Reintges Annika , Latif Mojib , Bordbar Mohammad Hadi , Park Wonsun
Published: March 2020

Multiyear to decadal predictability of the North Atlantic sea surface temperature (SST) is commonly attributed to buoyancy-forced changes of the Atlantic Meridional Overturning Circulation and associated poleward heat transport. Here we investigate the role of the wind stress anomalies in decadal hindcasts for the prediction of annual extratropical North Atlantic SST anomalies. A global climate model is forced by ERA-interim wind stress anomalies over the period 1979-2017. The resulting climate states serve as initial conditions for the decadal hindcasts. We find significant skill in predicting annual SST anomalies over the central extratropical North Atlantic with anomaly correlation coefficients exceeding 0.6 at lead times of 4 to 7 years. The skill of annual SSTs is basically insensitive to the calendar month of initialization. This skill is potentially linked to a gyre-driven upper-ocean heat content anomaly that leads anomalous SSTs by several years.
Mesoscale resolving high-resolution simulation of wind farms in COSMO-CLM 5
Authors: Akhtar Naveed , Rockel Burkhardt
Published: March 2020

The rapid development of offshore wind farms has raised concerns about the local environment and ecosystem. Wind farms influence the local meteorology by extracting kinetic energy from the wind field and by generating a large wake. The North Sea is one of the main regions of the world where the growth of offshore wind farms is rapidly increasing. In this study, we analyze the impact of large-scale offshore wind farms in the North Sea on local meteorology using regional climate model COSMO-CLM. For this purpose, the parametrization for wind turbine driven by Fitch et al. (2012) and Blahak et al. (2010), previously implemented in COSMO-CLM v 4.8 at KU-Leuven (Chatterjee et al. 2016), has been implemented in the latest version 5 of COSMO-CLM. Here we present the first results of COSMO-CLM long-term simulations with and without wind farms using mesoscale resolving high-resolution horizontal atmospheric grid spacing (~ 2 km).
Front detection using wind park data and NWP
Authors: Feldtkeller Franz , Kirsch Annekatrin , Denisenko Greta , Abel Markus
Published: March 2020

The precise forecasting of ramps in production of windparks is a problem that is not satifsfactorily solved. This is of particular interest because ramps contribute to a major part to the forecasting error in power production, in particular for offshore wind parks.

Since ramps are often due to fronts passing a location, we developed a method for the correction of front speed and -direction using a combination of wind park meteorological measurements and numerical weather prediction (NWP). On one hand we use conventional methods like the Canny algorithm for NWP data, on the other hand, we use data from a collection of wind parks to determine a passing front. By the front speed, and the relative location of wind parks, the front speed is computed and a correction can  be applied to downstream wind parks.

The results can be  validated and a corresponding error measure can be computed on the basis of measured and numerical data. Our method shall be implemented into a proprietary forecast system with the goal of an automatized detection and correction mechanism.
Hysteresis of tropical forests in the 21st century
Authors: Staal Arie , Fetzer Ingo , Wang-Erlandsson Lan , Bosmans Joyce , Dekker Stefan , van Nes Egbert , Rockström Johan , Tuinenburg Obbe
Published: March 2020

Tropical forests modify the conditions they depend on through feedbacks on different spatial scales. These feedbacks shape the hysteresis (history-dependence) of tropical forests, thus controlling their resilience to deforestation and response to climate change. Here we present the emergent hysteresis from local-scale tipping points and regional-scale forest-rainfall feedbacks across the tropics under the recent climate and a severe climate-change scenario. By integrating remote sensing, a global hydrological model, and detailed atmospheric moisture tracking simulations, we find that forest-rainfall feedback expands the range of possible forest distributions especially in the Amazon. The Amazon forest could partially recover from complete deforestation, but may lose that resilience later this century. The Congo forest lacks resilience, but gains it under climate change, whereas forests in Australasia are resilient under both current and future climates. Our results show how tropical forests shape their own distributions and create the climatic conditions that enable them.
A Status Report on the ILRS Contribution to ITRF2020
Authors: Luceri Vincenza , Pavlis Erricos C. , Basoni Antonio , Sarrocco David , Kuzmicz-Cieslak Magdalena , Evans Keith , Bianco Giuseppe
Published: March 2020

The International Laser Ranging Service (ILRS) Analysis Standing Committee (ASC) plans to complete the re-analysis of the SLR data since 1983 to end of this year by early 2021. This will ensure that the ILRS contribution to ITRF2020 will be available to ITRS by February 2021, as agreed by all space geodetic techniques answering its call. In preparation for the development of this contribution, the ILRS completed the re-analysis of all data (1983 to present), based on an improved modeling of the data and a novel approach that ensures the results are free of systematic errors in the underlying data. The new approach was developed after the completion of ITRF2014, the ILRS ASC devoting almost entirely its efforts on this task. A Pilot Project initially demonstrated the robust estimation of persistent systematic errors at the millimeter level, leading us to adopt a consistent set of a priori corrections for data collected in past years. The initial reanalysis used these corrections, leading to improved results for the TRF attributes, reflected in the resulting new time series of the TRF origin and scale. The ILRS ASC will now use the new approach in the development of its operational products and as a tool to monitor station performance, extending the history of systematics for each system that will be used in future re-analysis. The new operational products form a seamless extension of the re-analysis series, providing a continuous product based on our best knowledge of the ground system behavior and performance, without any dependence whatsoever on a priori knowledge of systematic errors (although information provided by the stations from their own engineering investigations are always welcome and taken into consideration). The presentation will demonstrate the level of improvement with respect to the previous ILRS product series and give a glimpse of what is to be expected from the development of a preliminary version of the ITRF2020.
A novel approach towards the reliable characterization of complex sedimentary aquifers
Authors: Vienken Thomas , Zech Alraune , Huber Emanuel , Huggenberger Peter , Kreck Manuel , Pohle Marco , Dietrich Peter , Werban Ulrike
Published: March 2020

The reliable characterization of heterogeneous sedimentary aquifers, especially the identification of preferential flow paths and their connectivity remains a challenge in applied hydrogeology research and practice. However, aforementioned information is crucial for predicting subsurface flow and contaminant transport in complex deposits. Well established characterization methods such as outcrop analogue studies, hydraulic tomography, tracer testing, and direct push profiling suffer from uncertainty due to non-uniqueness of underlying inversions or insufficient temporal and/or spatial data resolution. Furthermore, the relation and effects of observed heterogeneity in hydraulic conductivity on transport is not always straight forward.

A promising novel approach to overcome the limitations of conventional hydraulic site characterization techniques is the joint application of tracer testing and direct push logging. We present a proof-of-concept field study, where conventional salt tracer testing was combined with vertical high resolution direct push electrical conductivity profiling. The method successfully captured tracer distribution in heterogeneous sedimentary deposits in-situ and visualized measured tracer distribution over time. Additional measurements, such as breakthrough-curves and surface geophysics can be easily integrated to set up ex-post simulations to further increase site-specific understanding of groundwater flow and transport processes.
Brown carbon aerosol in urban Beijing: Significant contributions from biomass burning and secondary formation
Authors: Wang Ting , Huang Rujin , Yang Lu , Yuan Wei , Gong Yuquan
Published: March 2020

Atmospheric brown carbon (BrC) has significant impact on Earth’s radiative budget. However, due to our very limited knowledge about the relationship between BrC light absorption and the associated sources, the estimation for radiative effects of BrC is still largely constrained. In this study, we combine ultraviolet−visible (UV−vis) spectroscopy measurements and chemical analyses of BrC samples collected from January to December 2015 in urban Beijing, to investigated the sources of atmospheric BrC. The multiple liner regression model was applied to apportion the contributions of individual primary and secondary organic aerosol (OA) source components to light absorption of BrC. Our results indicated that biomass burning emission and secondary formation are highly absorbing up to 500 nm, and their contributions increased with the wavelengths. In contrast, the contribution of traffic emission and coal combustion to total absorption decreased with the wavelength and the large contributions were mostly found at shorter wavelengths. Then the mass absorption efficiency (MAE) of major light-absorbing components were estimated, which can provide a support to estimate the impact of BrC from these sources on the climate. The positive matrix factorization model were also used to verify the contributions of different source components of BrC absorption at 365 nm. The results consistently demonstrate that the biomass burning and secondary formation contributes significantly to the overall absorption, followed by coal combustion and traffic emission.
The rupture process of the Peru intermediate and deep earthquakes
Authors: López Sánchez Carolina , Buforn Elisa , Mattesini Maurizio , Tavera Hernando
Published: March 2020

The seismicity of Peru is associated with the subduction process of the Nazca plate under South America and characterized by the occurrence of shallow, intermediate and deep earthquakes. In this study, we focus our attention on the rupture process of earthquakes (Mw>6.0 ) that occurred during the period 2018-2019 at intermediate depth (50<h<200 km) and deep depth (500<h<700 km). Focal mechanisms have been estimated from slip inversion of body waves at teleseismic distances (Kikuchi and Kanamori, 1991). We investigate possible differences in the moment rate functions at different focal depths using our results and those provided by SCARDEC database. Furthermore, an estimation of the radiated seismic energy (ER) was provided from the direct integration of the velocity P wave recorded at teleseismic and regional distances, getting values between 1015 to 1016 J. The data were corrected by geometrical spreading, anelastic attenuation, and free surface effect. These results are interpreted in terms of the seismotectonics of the region
Improving Operational Numerical Prediction of Afternoon Thunderstorms over Taiwan through Surface Data Assimilation
Authors: Chen I-Han , Hong Jing-Shan , Tsai Ya-Ting , Fong Chin-Tzu
Published: March 2020

Taiwan, a subtropical island with steep mountains, is influenced by diverse weather systems, including typhoons, monsoons, frontal, and convective systems. Of these, the prediction of deep, moist convection here is particularly challenging due to complex topography and apparent landsea contrast. This study explored the benefits of assimilating surface observations on prediction of afternoon thunderstorms using a 2-km resolution WRF and WRFDA model system with rapid update cycles. Consecutive afternoon thunderstorm events during 30 June to 08 July 2017 are selected. Five experiments, consisting of 240 continuous cycles are designed to evaluate the data assimilation strategy and observation impact. Statistical results show that assimilating surface observations systematically improves the accuracy of wind and temperature prediction near the surface. Also, assimilating surface observations alone in one-hour intervals improves model quantitative precipitation forecast (QPF) skill, extending the forecast lead time in the morning. Furthermore, radar data assimilation can benefit by the additional assimilation of surface observations, particularly for improving the model QPF skill for large rainfall thresholds. An afternoon thunderstorm event that occurred on 06 July 2017 is further examined. By assimilating surface and radar observations, the model is able to capture the timing and location of the convection. Consequently, the accuracy of the predicted cold pool and outflow boundary is improved, when compared to the surface observations.
Hydroclimatological evaluation of CLM5 simulations using multiple data sources for land-atmosphere interaction studies over Scandinavia
Authors: Yılmaz Yeliz A. , Tallaksen Lena M. , Stordal Frode
Published: March 2020

Arctic amplification leads to rapid changes in the terrestrial water and energy balances at high northern latitudes. Advances in Earth System Models (ESMs) is improving our understanding of the underlying feedback mechanisms leading to these changes. The representation of the land surface in ESMs is essential to simulate and understand changes at the global and regional scales. The latest version of the land component of the Norwegian Earth System Model (NorESM), namely the Community Land Model (CLM5), has received substantial new implementations to help simulate the land surface processes in cold environments. At the same time, the behaviour of offline CLM5 simulations and new observational data sets have not been systematically compared over Scandinavian regions. In this study, we run the CLM5 model at relatively high resolution (0.25 degrees) over Scandinavia (including Svalbard) for 15 years between 2002 and 2016. We evaluate the water and energy budget components of CLM5 using several reanalyses and satellite-based observational data sets. In particular, we use monthly model outputs and compare with the satellite retrievals from GRACE, MODIS, AMSR2, and AMSR-E, and reanalysis data sets from ERA5, GLDAS, and MERRA-2. As an additional data source, we use the local‐scale measurements obtained from the Finse Eco-Hydrological Observatory (Finse EcHO) at 1200 m a.s.l, and the high-Arctic research site at Bayelva near Ny-Ålesund, Svalbard. Our investigation is focused on several variables including terrestrial water storage, snow water equivalent, turbulent fluxes, net radiation, and skin temperature. The results indicate that the perceived performance of the land surface model (CLM5) depends strongly on the reference observational data set. Regional discrepancies between data sets, particularly for Svalbard, prompts further investigation of the underlying sources of uncertainty. The results of this evaluation provide a valuable source of information for future studies in the region, particularly in the Land-ATmosphere Interactions in Cold Environments (LATICE) project, which focuses on cold region land surface dynamics, integrating across observational systems, laboratory experiments, field, and modeling efforts.

Acknowledgement : This study is conducted under the LATICE strategic research initiative funded by the Faculty of Mathematics and Natural Sciences at the University of Oslo, and the project EMERALD (294948) funded by the Research Council of Norway.
The Global Long-Term Agricultural Experiment Network
Authors: Cardoso Lisboa Carolina , Storkey Jonathan , Pellegrino Cerri Carlos Eduardo , Thierfelder Christian , Quincke Juan Andres , Chivenge Pauline , Snapp Sieglinde
Published: March 2020

Balancing food production with environmentally sustainable land management can have important climate change mitigation co-benefits. Recent reports, including the IPCC latest Special Report, launched at the COP 25 in December 2019, have highlighted the significant role of soil carbon (C) stocks in agricultural soils in achieving CO2 zero emissons and contributing to CO2 removal. However, to measure the soil C balance (C-gains and C-losses), a deep understanding of the processes governing the changes in soil C stocks in agricultural systems is required as well as knowledge on the impact of management over long and short time scales under distinct climate conditions. An understanding of the mechanisms underpinning these processes depends on robust evidence-based datasets that can be applied to several different models to model soil C-dynamics over time and make predictions upon future scenarios.  The datasets from long-term experiments (LTEs) can be extremely valuable to facilitate the evaluation of alternative food production systems impact/effect on soil health, as such soil C stocks. Employing modeling tools to analyse these data, would lead to better evaluation of land use and management practices and its environmental impacts around the globe. With the aim of supporting the agricultural science community in meeting this and related objetives, the Global Long-Term Agricultural Experiment Network (GLTEN) was launched in October 2019. The main goal of the network is to assemble and harmonize, following FAIR Data Principle (findable, accessible, interoperable and reusable), metadata from LTEs through the online GLTEN-Metadata Portal (https://glten.org/). This initial scientific investigation of the data shared between the experiments focusses on soil C data analyzed using free available tools to exploit and compare the trade-offs between several agricultural practices and C-offset given the distinct soil type and climate conditions. With the support of the GLTEN-members, we will start these joint analyses applying the Carbon Benefits Tools (https://banr.nrel.colostate.edu/CBP/) and the RothC Model (https://www.rothamsted.ac.uk/rothamsted-carbon-model-rothc). The progress of this collaborative work relies on the commitment and expertise of the GLTEN-members and we expect that the outcome from this investigation will support the knowledge refining and advancing the development of existing modeling tools. Furthermore, we will demonstrate the potential for the GLTEN to provide a platform that supports and facilitates collaborative research among the community.
Climate impact of clear air turbulence induced mixing in the UTLS
Authors: Tost Holger , Hoor Peter
Published: March 2020

The upper troposphere / lower stratosphere (UTLS) region has been identified as a region with a high climate sensitivity of the Earth's atmosphere. Past studies have shown that mixing processes can have a substantial impact on the radiative budget of the atmosphere with implications for the climate of the planet. However, in most large-scale models some of these mixing processes are hardly resolved or considered explicitely.
In this study, we focus on clear air turbulence (CAT) as a dynamically driven mixing process, which can induce vertical mixing of radiative active trace gases. For this purpose, we have equipped a chemistry-climate model with a diagnostics for dynamical CAT including vertical stability conditions and a mixing parameterisation for CAT-induced vertical exchange of trace gases.  
With the help of this tool we analyse the occurrence of CAT, the mixing of chemical compounds and the resulting radiative impact of this mixing.
The model simulations indicate a more efficient mixing of trace species in the UTLS, weakening some of the strong gradients of compounds, such that an occasional deeper penetration into the lower stratosphere becomes possible.
A suitable choice of simulation configuration also allows us to disentangle the radiative forcing of climate active gases (e.g., N2O, O3, CH4) from
feedback processes occurring in the holistic system. 
UK Climate Projections 2018 (UKCP18): progress towards more information on future weather
Authors: Sexton David , Lowe Jason , Murphy James , Harris Glen , Kendon Elizabeth , Fung Fai , McSweeney Carol , Rostron John , Yamazaki Kuniko , Thornton Hazel , Fosser Giorgia , Tucker Simon , Bett Philip
Published: March 2020

UK Climate Projections 2018 (UKCP18) included land and marine projections and were published in 2018 to replace UKCP09. The land projections had three components, and all were designed to provide more information on future weather compared to UKCP09. The first component updated the UKCP09 probabilistic projections by including newer CMIP5 data and focussing on seasonal means from individual years rather than 30-year averages. The probabilistic projections represent the wider uncertainty. The second two components (global and regional projections) both had the aim of providing plausible examples of future climate, but at different resolutions.

The global projections were a combination of 13 CMIP5 models and a 15-member perturbed parameter ensemble (PPE) of coupled simulations for 1900-2100 using CMIP5 RCP8.5 from 2005 onwards. The PPE was provided at 60km atmosphere, quarter degree ocean and the large-scale conditions from twelve of the members were used to drive the regional model at both 12km and 2.2km resolution. These plausible examples are more useful for providing information about weather in a future climate to support a storyline approach for decision making.

The talk will present examples of new ways to use UKCP18 compared to UKCP09.  We will show how the global projections can be used to understand that the recent record winter daily maximum temperature in the UK in 2019 had a large contribution from internal variability and what this means for breaking the record in a warming climate. We also use an example from China to demonstrate one way to exploit information at different time scales, looking at how a circulation index, which is predictable and related to tropical cyclone landfall, changes in a future climate.

Finally, we show that while the enhanced resolution of the global and regional projections has improved our capability to provide climate information linked to the better representation of circulation, they lack diversity in some of the key drivers of future climate. Therefore, a key way forward will be to find an appropriate balance between the need for better diversity (e.g. multiple ensembles such as CMIP or PPEs) and the need for an appropriate resolution to retain this new capability.
Assessing future hurricane risk in the Caribbean based on large-scale predictor fields
Authors: Pfleiderer Peter , Schleußner Carl-Friedrich
Published: March 2020

Hurricanes are the most damaging natural disasters in the Caribbean and global warming is expected to increase their impacts. It is well understood that tropical cyclones (TC) will intensify as sea surface temperatures warm and that the amount of precipitation brought by these TCs is going to increase with the water holding capacity of the atmosphere. However, for an assessment of future hurricane risk in the Caribbean it also important to better understand whether and how the overall frequency of tropical cyclones might change.

Projecting future tropical cyclone activity remains challenging because of the weak representation of tropical cyclones in most global circulation models. Here we want to overcome this shortcoming by estimating hurricane risk indirectly based on favorable climatic conditions in the region. These large-scale predictor fields are easier to model and therefore allow for an improved assessment of future hurricane risk.

We define hurricane risk as the accumulated energy that TCs produce in proximity of Caribbean islands. Using novel statistical methods, we identify regions of sea surface temperature, wind speeds and sea level pressure with predictive power for the next weeks hurricane activity. Based on these predictors we construct a classification model to estimate the probability of having TCs in proximity of islands and their strength for the following week. The expected value of seasonal hurricane risk based on these weekly probabilities shows high skill in reproducing the observational record.

Applying the same hurricane risk model to climate projections from global circulation models allows us to estimate future hurricane risk without relying on the ability of climate models to adequately represent tropical.
Prospection of geo-resources for the building of social houses in Cuba
Authors: Martín Sánchez Domingo Alfonso , Costafreda Mustelier Jorge Luis , Presa Madrigal Leticia , García Laso Ana , Rodríguez Rama Juan Antonio
Published: March 2020

The Spanish group of the IAPG has one of its strategic areas focused on development cooperation, in order to solve environmental, ethical and social problems related to the management of geological resources. One of the branches of this cooperation focuses on natural materials prospection which can be used as cheap additives in the construction process. As a result of this line, a cooperation project was carried out framed in the program of the Universidad Politécnica de Madrid (UPM) with Latin America, specifically with the University of Moa, province of Holguín (Cuba). This research aims to characterize the deposits of natural pozzolans in the northeastern region of Cuba, and determine their possible applications in the manufacture of cements and mortars for the construction of social housing in that region. The tasks contemplated in the development of this project are divided into two fundamental parts; the first one, which describes the field campaigns in situ in which geological survey and sampling work was carried out, with the assimilation of natural samples from the selected deposits, as well as samples of slag extracted from a steel plant. The second part refers to the laboratory campaign, in which a great variety of tests have been carried out to determine the suitability of the samples, among which are mentioned: X-ray diffraction, scanning electron microscopy, chemical analysis, pozzolanicity, granulometric test, specific surface, real density, freezing, mechanical resistance and determination of the speed of propagation of the ultrasound. After analyzing the results obtained, it is concluded that the samples studied have the properties and characteristics necessary for the manufacture of cements and mortars with pozzolanic characteristics, justifying, in this way, the manufacture of products with a moderate production cost and with the quality for the construction of social housing and infrastructure, so necessary in the study area.
Hydrology, electron acceptor availability and organic matter decomposition in Dutch peatland pastures
Authors: Boonman Jim , van Huissteden Ko , Dolman Han , van der Velde Ype
Published: March 2020

The Netherlands plans to cut greenhouse gas emissions by 1 megaton CO2-equivalents in 2030 by implementing measures reducing peat decomposition. In order to achieve this, a national research program on peatland pasture greenhouse gas emissions has been set up. In the program, five peatland sites with each two fields, with and without submerged tube drainage systems, are continuously monitored. Here, we present our research with the objective to understand the rate of biochemical peat decomposition by assessing electron acceptor availability from a hydrological perspective. Soil (< 100 cm depth) redox conditions are continuously measured at five depths. Preliminary data on soil electron acceptor availability distribution suggest counterintuitive behavior of the peat soils. We find reducing conditions in the topsoil (0-20 cm) and oxidative conditions in the subsoil (40-80 cm) for the sites without tube drainage. For sites with tube drainage, we find oxidative conditions in the topsoil (0-20 cm) and reducing conditions starting at 60 cm depth at the drain location and at 80 cm depth between the drains. A novel 2D groundwater model is being set up, enabling to capture saturation dynamics, water origin and solute transport in the peat soil. We will present our modelling setup and initial simulation results for water origin and travel paths. These results will indicate how electron acceptors are distributed through the soil, helping to interpret redox measurements in the field at different depths. In a later stage of the research, the effects of redox conditions on microbial soil respiration will be evaluated with greenhouse gas chamber and eddy covariance measurements.
SEPTEMBER 26, 2019 Mw5.8 MARMARA SEA-SILIVRI (ISTANBUL) EARTHQUAKE: ANALYSIS OF GROUND MOTION RECORDS
Authors: Okuyan Akcan Seyhan , Zulfikar Can
Published: March 2020

Marmara region located on the western end of the North Anatolian Fault Zone is a tectonically active region in Turkey. There have been frequent severe earthquakes in the region and will continue to occur. There was no serious earthquake in the region after the 1999 Mw7.4 Kocaeli and Mw7.2 Düzce earthquakes. A Marmara Sea offshore earthquake Mw5.8 close to Silivri Town of Istanbul Metropolitan City has occurred on September 26, 2019 daytime at 13:59. The earthquake happened at the coordinate of 40.87N – 28.19E with a depth of 7.0km on the Kumburgaz segment of the North Anatolian Fault line. It was felt in almost all Marmara region. In some settlements in Istanbul City, slight to moderate damages were observed. A foreshock earthquake of Mw4.8 occurred on the same segment on 24 September, 2019. 150 aftershock events ranging from M1.0 to M4.1 have been recorded within the 24 hours after the mainshock. The ground motions have been recorded in the region by the several institutions including AFAD (Disaster and Emergency Management Presidency), KOERI (Kandilli Observatory and Earthquake Research Institute) and IGDAS (Istanbul Gas Distribution Industry and Trade Inc.). The ground motion records and selected parameters have been examined in this study. The ground motion parameters (MMI, PGA, PGV, Sa, Sv, Sd) distribution have been achieved and checked by the recent NGA-West2 ground motion prediction equations (GMPEs); ASK2014, CY2014 and BSSA2014. The compatibility of the GMPEs for a moderate size Marmara Sea earthquake has been examined.
Moho beneath Tibet based on a joint analysis of gravity and seismic data
Authors: Zhao Guangdong , Liu Jianxin , Chen Bo , K. Kaban Mikhail
Published: March 2020

The Tibetan Plateau, known as the roof of the Earth, is considered as the “Golden Key” for understanding plate tectonics, continental collisions and continental orogenic formation. A reliable Moho structure is also vital for understanding the deformation mechanism of the Tibetan Plateau.

In this study, we use improved Parker−Oldenburg’s formulas that include a reference depth into the exponential term and employ a Gauss-FFT method to determine Moho depths beneath the Tibetan Plateau. The synthetic models demonstrate that the improved Parker’s formula has higher accuracy with the maximum absolute error less than 0.25 mGal.

Two inversion parameters, namely the reference depth and the density contrast are essential for the Moho estimation based on the gravity field, and they need to be determined in advance to obtain correct results. Therefore, the Moho estimates derived from existing seismic studies (Stolk et al., 2013) are used to reduce the non-uniqueness of the gravity inversion and to determine these parameters by searching for the maximum correlation between the gravity-inverted and seismic-derived Moho depths.

Another critical issue is to remove beforehand the gravity effects of other factors, which affect the observed gravity field. In addition to the topography, the gravity effects of the sedimentary layer and crystalline crust are removed based on existing crustal models, while the upper mantle impact is determined based on the seismic tomography model.

The inversion results show that the Moho structure under the Tibetan plateau is very complex with the depths varying from about 30 ~ 40 km in the surrounding basins (e.g., the Ganges basin, the Sichuan basin, and the Tarim basin) to 60 ~ 80 km within the plateau. This considerable difference up to 40 km on the Moho depth reveals the substantial uplift and thickening of the crust in the Tibetan Plateau.

Furthermore, two visible “Moho depression belts” are observed within the plateau with the maximum Moho deepening along the Indus-Tsangpo Suture and along the northern margin of Tibet bounding the Tarim basin with the relatively shallow Moho in central Tibet between them. The southern “belt” is likely formed in compressional environment, where the Indian plate underthrusts northwards beneath the Tibetan Plateau, while the northern one could be formed by the southward underthrust of the Asian lithosphere beneath Tibet.

Stolk, W., Kaban, M., Beekman, F., Tesauro, M., Mooney, W. D., & Cloetingh, S. (2013). High resolution regional crustal models from irregularly distributed data: Application to Asia and adjacent areas. Tectonophysics, 602, 55-68. https://doi.org/10.1016/j.tecto.2013.01.022
Geoeffectiveness of Magnetosheath Jets
Authors: Norenius Linus , Hamrin Maria , Goncharov Oleksandr , Gunell Herbert , Karlsson Tomas , Opgenoorth Hermann , Chong Siung
Published: March 2020

The study on high speed plasma flows in the Earth’s magnetosheath, or commonly known as jets, has been a popular topic for discussion in recent decades. These jets can often be characterised by increases in the dynamic pressure compared to the background plasma. They can propagate through the magnetosheath and impact the magnetopause, causing indentations and possibly triggering waves on the magnetopause and contribute to energy and mass transfer into the magnetosphere. Previous studies suggest that the effects from these impacts are detectable inside the magnetosphere at geostationary orbit, and even at ground level causing geoeffective responses. Case studies show indications where ground based magnetometers, GMAGs, have observed magnetic pulses as a result of impacting jets. By using data from the MMS mission and GMAGs, we conduct an observational study with a larger set of jets compared to previous works. The geoeffectiveness of these jets will be investigated and the properties of the responses in the GMAG observations will be discussed.
Intelligent management of reservoir and photoelectric ponds under water-food-energy nexus perspective
Authors: Lee Wei-De , Chang Fi-John
Published: March 2020

The world is in a crucial era of energy transition, and green energy will serve as a new engine that drives sustainable development in the future. Renewable energy becomes the core energy to cultivate green energy industries and promote energy self-sufficiency in Taiwan. In recent years, water, food and energy nexus (WFE Nexus) has gained global attention. Therefore, a multi-objective optimization framework is proposed in this study to explore the optimal solution to the WFE Nexus for improving the synergistic benefits of water, food, and energy (hydropower, small hydropower and solar power). The joint multi-objective operation of the Shihmen Reservoir and irrigation ponds in the northern Taiwan constitutes the case study. This study aims at achieving the optimal water supply to fulfill basic demands from different sectors as well as increasing green energy output by utilizing reservoir spilled water to lift up hydropower output, installing small hydropower in river channels, and setting up solar panels over irrigation ponds. The results support the high potential of photoelectric ponds because the installation of solar panels over irrigation ponds can 1) reduce evaporation amount and water temperature and 2) provide water quality conditions suitable for growing fish while increasing solar power output. The results also indicate that the optimal joint operation of the Shihmen Reservoir and irrigation ponds can promote reservoir hydropower output and the small hydropower output in river channels while increasing water supply and food production. This study demonstrates that the intelligent management of the reservoir and photoelectric ponds not only can increase green energy production, water supply and food production but also can enhance the synergistic benefits of the WFE Nexus, which provides long/short term policies for sustainable urban development.

 

Keywords: Multi-objective reservoir operation; Optimization; Water, food and energy nexus (WFE Nexus); Green energy; Greenhouse