bluuebunny/crossref_metadata_2025 huggingface dataset:
X-ray computed microtomography to predict CO2 emissions in casts of 6 earthworm species (Lumbricidae)
Authors: Le Mer Guillaume , Bottinelli Nicolas , Dignac Marie-France , Mazurier Arnaud , Caner Laurent , Rumpel Cornelia
Published: March 2020

Plant residues are the main precursors of soil organic matter (SOM) and soil macrofauna is an important driver of ecological processes involved in the sequestration of carbon (C) in soils. In particular, earthworms are one of the largest contributors to soil matter formation in most terrestrial ecosystems. In the short term, they may increase the rate of OM turnover by mineralization, fragmentation and stimulation of microbial activity. On the other hand they may reduce OM degradability by forming stable aggregates and organo-mineral complexes protecting C from mineralization for longer time scales. Earthworms are classified in three main ecological groups depending on their behaviors and on their morpho-functional traits. However, their intra- or inter- ecological group effect on C stabilization needs to be investigated.

In this study, we explored the impact of earthworm diversity (composed of several species belonging to different ecological groups) on the physicochemical properties of casts, related to CO2 emissions. We hypothesized that C mineralization in casts would be related to the ecological category.

We studied casts of 6 species (2 anecic species: Lumbricus terrestris & Aporectodea nocturna, 2 endogeic species: Allolobophora icterica & Aporrectodea caliginosa and 2 epigeic species: Lumbricus castaneus & Eisenia fetida) produced in a silty subsoil with addition of plant litter. Casts were incubated for 140 days under similar laboratory conditions. We measured CO2 mineralization, pH, elemental composition and physical cast organization by X-ray microtomography (resolution of 9.49 µm voxel) at 7, 42, and 140 days.

Our results showed lower CO2 mineralization in aggregates produced without earthworms than all earthworm casts. In the beginning of the incubation casts showed similar CO2 emissions and specific physicochemical properties as OC content and pH. After 140 days, CO2 emissions were earthworm species specific with Aporectodea nocturna showing highest CO2 emissions, and Aporrectodea caliginosa the lowest values. Microtomographic analyses showed that this is due to an increase of cast porosity with increasing cast age coupled with a concurrent decrease particulate organic matter (POM) structures. Our first results seemed to suggest that earthworms belonging to the same ecological category influence similarly C mineralization through their impact on the cast organization.
Assessment of Multiplatform Satellite Image Frequency for Crop Health Monitoring
Authors: Kovalskyy Valeriy , Yang Xiaoyuan
Published: March 2020

Imagery products are critical for digital agriculture as they help delivering value and insights to growers. Use of publicly available satellite data feeds by digital agriculture companies helps keeping imagery services affordable for broader base of farmers. Optimal use of public and private imagery data sources plays a critical role in the success of image based services for agriculture. 

At the Climate Corporation we have established a program focused on intelligence about satellite image coverage and frequency expected in different geographies and times of the year which is becoming critical for global expansion of the company. In this talk we report the results of our analysis on publicly available imagery data sources for key agricultural regions of the globe. Also, we demonstrate how these results can guide commercial imagery acquisition decisions on the case study in Brazil, where some growers run the risk of going through the growing season without receiving imagery from one satellite if relying on a single source of satellite imagery. The study clearly shows the validity of approaches taken as the results matched with factual image deliveries to single digits of percent cover on regional level. Also, our analysis clearly captured realistic temporal and spatial details of chances in image frequency from addition of alternative satellite imagery sources to the production stream. The optimization in imagery acquisitions enables filling data gaps for research and development. In the meantime, it contributes to delivering greater value for growers in Crop Health Monitoring and other image based service. 
Forecasting drought revisited – the importance of spectral transformations to dominant atmospheric predictor variables
Authors: Sharma Ashish , Jiang Ze , Johnson Fiona
Published: March 2020

As we write this abstract, Australia is experiencing widespread forest fires, Sydney has declared significant water restriction measures curtailing demand, and the entire country is experiencing a drought that is amongst the worst on record. Formulating a stable and practical approach for predicting drought into the future is being realised as an important need, as we enter an era of warmer climates that complicate this problem to an even greater extent. This study presents a novel basis for forecasting drought into the future. Use is made of a recently developed wavelets based methodology for transforming predictor variables so as to force greater consistency in spectral attributes with the response being modelled. Using a commonly adopted drought index, we demonstrate how the wavelets transformed predictor variables can be used to model the response with greater accuracy than otherwise. These transformed predictor variables are then used in conjunction with CMIP5 decadal climate forecasts to demonstrate the accuracy attainable at longer lead times than is currently possible. While our application focusses on the Australian mainland, the method is generic and can be adopted anywhere.
The response of deep soil carbon to climate change: Empirical studies from forests to farmland and the tropics to the arctic
Authors: Hicks Pries Caitlin
Published: March 2020

Over half of global soil organic carbon (SOC) is stored in subsurface soils (>20 cm depth), but the vulnerability of this deeper SOC to climate change has only begun to be tested. Most soil warming experiments have either only warmed surface soils or only examined the response of the surface carbon dioxide flux, so the sensitivity of SOC at different soil depths and the potential of various soil depths to generate a positive feedback to climate change is undetermined. As predictive models of terrestrial carbon storage move toward more mechanistic process representations, we need to understand how the carbon cycle differs across soil depths. We present depth-explicit measurements of soil CO2 production from seven studies, including five in situ deep soil warming experiments and two laboratory incubations. The experiments’ locations ranged from coniferous to hardwood temperate forests in the United States and from volcanic soils in Hawaii to agricultural soils in France. The incubated soils came from a former agricultural field and arctic tundra. We have found that in temperate forests, deep soil carbon is just as vulnerable to warming-induced losses as surface soils and that warming has caused a shift in the source of carbon being respired at all depths. However, where minerals are strongly associated with organic carbon, as in Hawaii, or in degraded soils where much of the organic carbon has been lost, deep soil carbon is not vulnerable to warming-induced losses. Thus, the response of deep soil to climate change seems to be dependent on how available deep soil carbon is to microbes.
Effects of ecological construction on the transformation of different water types on Loess Plateau, China
Authors: Zhao Binhua , Li Zhanbin
Published: March 2020

Water is the most essential resource for the ecological and biological survival of organisms as well as being an important strategic socio-economic factor. Stable isotopes of δD and δ18O in water are important indicators of hydrological and ecological process. In this study, temporal and spatial variations in δD and δ18O and transformations between three water bodies (precipitation, stream water, and groundwater) under ecological construction were studied in two contrasting watersheds of the Wuding River, China. In order to understanding the spatial and temporal variation of stable isotopes and water transmission times (WTT) under ecological construction, a total of 1028 water samples were collected from the 30 sites, and 79 precipitation samples were collected at the weather station. The results show that variation range of three water bodies occurred in the order
precipitation>stream water>groundwater, the local meteoric water line was above the level of the last two, and the isotopic composition of stream water and groundwater in controlling watershed is more enriched than that in natural watershed. WTT from precipitation to stream water in Jiuyuangou were 1.53 times those of Peijiamao. Similarly, WTT from precipitation to groundwater was about 7.6 times than that form precipitation to stream water. Supply ratios exhibited obvious seasonal variation. Precipitation and groundwater recharged stream water mostly in the dry season, while precipitation and stream water recharged groundwater during the wet season. Overall, this study shows that ecological construction measures extend WTTs and enhance water evaporation and fractionation. The results of this research are significant as they enhance our understanding of water transformation on the Loess Plateau under ecological construction.
Potential state shifts in terrestrial ecosystems related to changes in El Niño-Southern Oscillation dynamics
Authors: Duque-Villegas Mateo , Salazar Juan Fernando , Rendón Angela Maria
Published: March 2020

The El Niño-Southern Oscillation (ENSO) phenomenon is regarded as a policy-relevant tipping element of the Earth's climate system. It has a prominent planetary-scale influence on climatic variability and it is susceptible to anthropogenic forcing, which could alter irreversibly its dynamics. Changes in frequency and/or amplitude of ENSO would have major implications for terrestrial hydrology and ecosystems. The amount of extreme events such as droughts and floods could vary regionally, as well as their intensities. Here, we use an intermediate complexity climate model, namely the Planet Simulator (PlaSim), to study the potential impact on Earth's climate and its terrestrial ecosystems of changing ENSO dynamics in a couple of experiments. Initially we investigate the global effects of a permanent El Niño, and then we analyse changes in the amplitude of the fluctuation. We found that PlaSim model yields a sensible representation of current large-scale climatological patterns, including ENSO-related variability, as well as realistic estimates of global energy and water budgets. For the permanent El Niño state, there were significant differences in the global distribution of water and energy fluxes that led to asymmetrical effects on vegetation production, which increased in the tropics and decreased in temperate regions. In terrestrial ecosystems of regions such as western North America, the Amazon rainforest, south-eastern Africa and Australia, we found that these El Niño-induced changes could be associated with biome state transitions. Particularly for Australia, we found country-wide aridification as a result of sustained El Niño conditions, which is a potential state in which recent wildfires would be even more dramatic. When the amplitude of the ENSO fluctuation changes, we found that although mean climatological values do not change significantly, extreme values of variables such as temperature and precipitation become more extreme. Our approach aims at recognizing potential threats for terrestrial ecosystems in climate change scenarios in which there are more frequent El Niño phenomena or the intensities of the ENSO phases change. Although it is not enough to prove such effects will be observed, we show a consistent picture and it should raise awareness about conservation of global ecosystems.
Challenges, trade-offs, and opportunities in the design of power transmission lines: a water-energy perspective
Authors: Galelli Stefano , Chowdhury AFM Kamal , Dang Thanh Duc
Published: March 2020

High-voltage transmission lines provide the fundamental service of delivering electricity over long distances, connecting power plants to demand centers. Their role is particularly critical in energy systems characterized by the presence of hydropower, and other renewable resources, whose output exhibits trends and shifts in response to hydro-climatic variability. Yet, the design and operation of transmission networks is rarely placed within a broad water-energy context, often resulting in infrastructures unable to dispatch the available power during peak-production periods. The case in point is Laos: the country has attracted large investments in the hydropower sector, but their effectiveness is severely limited by the capacity of the high-voltage transmission facilities. Here, we show how such challenge could be tackled through the use of process-based models describing the interconnections between water, energy, and power transmission components. Specifically, we run our modelling framework over a broad range of hydro-climatic conditions, so as to identify the transmission lines severely limited by their capacity. With this information at hand, we then explore the potential of both design and management interventions. Potential solutions include the capacity expansion of a few transmission lines and the adoption of a wide area synchronous grid, which facilitates electricity exchange across Laos and Thailand. Results show that both solutions are cost-effective: they require limited investment costs and reduce reliance on fossil fuels, resulting in a significant abatement of CO2 emissions.
Projected near-term changes in three types of heat waves over China under RCP4.5
Authors: Su Qin
Published: March 2020

The changes in three aspects of frequency, intensity and duration of the compound, daytime and nighttime heat waves (HWs) over China during extended summer (May–September) in a future period of the mid-21st century (FP; 2045-2055) under RCP4.5 scenario relative to present day (PD; 1994-2011) are investigated by two models, MetUM-GOML1 and MetUM-GOML2, which comprise the atmospheric components of two state-of-the-art climate models coupled to a multi-level mixed-layer ocean model. The results show that in the mid-21st century all three types of HWs in China will occur more frequently with strengthened intensity and elongated duration relative to the PD. The compound HWs will change most dramatically, with the frequency in the FP being 4–5 times that in the PD, and the intensity and duration doubling those in the PD. The changes in daytime and nighttime HWs are also remarkable, with the changes of nighttime HWs larger than those of daytime HWs. The future changes of the three types of HWs in China in two models are similar in terms of spatial patterns and area-averaged quantities, indicating these projected changes of HWs over the China under RCP4.5 scenario are robust. Further analyses suggest that projected future changes in HWs over China are determined mainly by the increase in seasonal mean surface air temperatures with change in temperature variability playing a minor role. The seasonal mean temperature increase is due to the increase in surface downward longwave radiation and surface shortwave radiation. The increase in downward longwave radiation results from the enhanced greenhouse effect and increased water vapour in the atmosphere. The increase in surface shortwave radiation is the result of the decreased aerosol emissions, via direct aerosol-radiation interaction and indirect aerosol-cloud interaction over southeastern and northeastern China, and the reduced cloud cover related to a decrease in relative humidity.
The chronosequence in context: Elevation-dependent dynamics of soil biogeochemistry during cloud forest succession
Authors: Looker Nathaniel , Margenot Andrew , McFarlane Karis , Nater Ed , Plante Alain , Kolka Randy
Published: March 2020

In mountainous landscapes, rates of soil morphological and biogeochemical change during secondary forest succession (SFS) can vary widely with elevation due to gradients in water, energy, and mineral weathering status. Improved understanding of how elevation mediates the response of soils to SFS is critical not only for reducing the uncertainty of soil maps in complex terrain, but also for predicting the edaphic effects of SFS under future climatic conditions. Focusing on volcanic ash soils in Veracruz, Mexico, we sought to 1) quantify how elevation mediates the dynamics of soil organic carbon (SOC) and geochemistry during SFS and 2) disentangle the soil-forming processes responsible for altitudinal trends. We characterized 16 soil profiles (0-100 cm depth) at various stages of SFS after pasture abandonment at the lower and upper altitudinal limits of the cloud forest ecosystem (1350-1550 and 2050-2220 m) using a broad suite of analytical techniques. Elevation strongly affected the depth distributions of all measured inorganic elements and enhanced the rate of accumulation of biocycled elements (e.g., P, K, Ca, S, Mn) during SFS. Notwithstanding altitudinal differences in C inputs (namely, forest floor recovery rates), profile-level SOC composition and dynamics were more sensitive to mineral weathering status than to SFS stage or elevation per se. Differentiation of soil mineralogy and SOC dynamics contributed to variation of physical properties, consistent with local ‘folk’ soil taxonomy. Ongoing work addresses the interplay of climate, geology, and redistribution processes in determining the mineralogical properties and, ultimately, SOC dynamics of volcanic ash soils. Our findings underscore the importance of considering the complex environmental contingency of soil recovery rates during SFS.
Surface rupture and landscape response within the core of the great Mw 8.3 1934 earthquake mesoseismal area: the case of the Khutti Khola
Authors: Riesner Magali , Bollinger Laurent , Rizza Magali , Klinger Yann , Sapkota Soma Nath , Guérin Cyrielle , Karakaş Çağıl , Tapponnier Paul
Published: March 2020

Great earthquakes generated along the Himalayan mega-thrust plate boundary have been shown to rupture the surface. The Mw 8.3 1934 Bihar-Nepal earthquake is one of these major seismotectonic events. Previous studies focused on sites located at the western end of the fault trace concluded that the surface rupture associated with this earthquake is still locally preserved. Here we document a new site, along the Khutti Khola rivercut, in the core of the mesoseismal area. The effects of the earthquake in that area were described as cataclysmic, generating massive damages, landslides blocking one of the local rivers at 4 sites. The Khutti river cuts the frontal range, incising a 4 m- high cumulated scarp exposed along a 19 m-long stretch of Siwaliks claystone-sandstone and alluvial deposits. A detailed study of the river cut revealed the presence of faults emplacing Siwaliks over quaternary alluvials. These units are sealed by a colluvial wedge and wash as well as by recent underformed alluvials. The C14 radiocarbon analyses of 10 detrital charcoals collected reveal that the last surface-rupturing event at that site occurred after the 17th century and prior to the post-bomb deposition of the young alluvials. The only historical earthquake known within that period is the 1934 earthquake, inferring that for this event the rupture reached the surface at that site. The rupture was followed by rapid aggradation and sealed by ~2 meters of sediments. In addition to being another rare example for the preservation of the 1934 earthquake, these observations demonstrate that, despite their magnitude and potential surface rupture, the study of the great Himalayan paleo-earthquakes are still challenging however necessary to constrain their lateral extent.
Dominant Characteristics of early autumn Arctic sea ice variability and its impact on Winter Eurasian climate
Authors: Ding Shuoyi , Wu Bingyi , Chen Wen
Published: March 2020

The present study investigated dominant characteristics of autumn Arctic sea ice concentration (SIC) interannual variations, and examined impacts of SIC anomalies in the East Siberian-Chukchi-Beaufort (EsCB) Seas on winter Eurasian climate variability and the associated possible physical mechanism. Results showed that the Arctic SIC variations in both September and October display a certain continuity to some extent, thus, we chose the September-October (SO) mean SIC as a factor to explore its delayed impacts on winter atmosphere. Dominant features of Arctic SIC variability in SO is characterized by sea ice loss in the EsCB Seas, with more evident interannual variability since the late 1990s. Such a change can be attributed to the central Arctic pattern of atmospheric variability. Along with the global warming, the interannual variation of sea ice in the EsCB Seas seemingly exerts an increasingly role in the Northern Hemispheric climate variability. When the EsCB sea ice decreases in the early autumn (SO), a barotropic response of wave number 2 structure with significant warming and positive geopotential height anomaly dominates the Arctic region a month later. Then, in the early winter (ND(0)J(1)), the Arctic anticyclonic anomaly extends southward into the central-western Eurasia and leads to evident surface cooling there. Two month later, it further develops toward downstream accompanied by a deepened trough, making the East Asia experience a colder late winter (JFM(1)), especially in the northeastern China. Meanwhile, enhanced North Pacific anticyclonic perturbation excites an eastward wave train and contributes to positive geopotential height anomaly around the Greenland. Combined with a cyclonic anomaly to its southeast, a dipole structure forms and favors negative surface temperature anomaly covering the western Europe. In addition, a weakened polar vortex in the lower stratosphere can be observed during the boreal winter. Similar atmospheric responses to EsCB sea ice loss are well reproduced in the simulation experiments, not only supporting the conclusions from observational analyses, but also illustrating the possible physical mechanism to some extent.
Combined Effects of Synoptic-Scale Teleconnection Patterns on Summer Precipitation in Southern China
Authors: Wang Chao
Published: March 2020

Using ERA-Interim daily reanalysis and precipitation data, the combined effects of East Asia-Pacific (EAP) and Silk Road (SR) teleconnection patterns on summer precipitation in southern China were investigated on synoptic to sub-monthly timescales. Combined EAP and SR patterns lead to more persistent and extreme precipitation in the Yangtze River Valley (YRV) and exhibit an obvious zonal advance between the South Asia High (SAH) and Western Pacific Subtropical High (WPSH) prior to its onset. During typical combined events, an overlap between the SAH and WPSH remains in a favorable position for Persistent Extreme Precipitation (PEP). Furthermore, SR-induced acceleration of the westerly jet stream and extra positive vorticity advection provide persistent upper-level divergence for YRV precipitation. An anomalous EAP-related cyclone/anticyclone pair over East Asia induces enhanced low-level southwesterlies to the northern anticyclone flank and northerlies from the mid-latitudes, advecting anomalously abundant moisture toward the YRV, resulting in clear moisture convergence. Moreover, the strong ascent of warmer/moister air along a quasi-stationary front may be crucial for PEP. During decay, the SAH and WPSH diverge from each other and retreat to their normal positions, and the strong ascent of warmer/moister air rapidly weakens to dissipation, terminating PEP in the YRV.
Data dissemination best practices and challenges identified through NOAA’s Big Data Project
Authors: Richardson Meredith , Kearns Ed , O'Neil Jonathan
Published: March 2020

Through satellites, ships, radars, and weather models, the National Oceanic and Atmospheric Administration (NOAA) generates and handles tens of terabytes of data per day. Many of NOAA’s key datasets have been made available to the public through partnerships with Google, Microsoft, Amazon Web Services, and more as part of the Big Data Project (BDP). This movement of data to the Cloud has enabled access for researchers from all over the world to vast amounts of NOAA data, initiating a new form of federal data management as well as exposing key challenges for the future of open-access data. NOAA researchers have run into challenges of providing “analysis-ready” datasets to which researchers from varying fields can easily access, manipulate, and use for different purposes. This issue arises as there is no agreed-upon format or method of transforming traditional datasets for the cloud across research communities, with each scientific field or start up expressing differing data formatting needs (cloud-optimized, cloud-native, etc.). Some possible solutions involve changing data formats into those widely-used throughout the visualization community, such as Cloud-Optimized GeoTIFF. Initial findings have led NOAA to facilitate roundtable discussions with researchers, public and private stakeholders, and other key members of the data community, to encourage the development of best practices for the use of public data on commercial cloud platforms. Overall, by uploading NOAA data to the Cloud, the BDP has led to the recognition and ongoing development of new best practices for data authentication and dissemination and the identification of key areas for targeting collaboration and data use across scientific communities.
Site-Specific Characterization of Earthquake Ground Motions: Papua New Guinea Case Study
Authors: Novakovic Mark , Yenier Emrah , Hovey Andrew , Quinn Joseph , Witten Benjamin
Published: March 2020

A seismic hazard analysis was conducted for a site in Papua New Guinea which is located in a seismically-active region that experiences frequent large earthquakes generated by crustal and subduction sources.  A suite of ground motion prediction equations (GMPEs) was developed for each source type (crustal, interface and in-slab) using the scaled-backbone approach.  To this end, a ground-motion database consisting of events of 4.0<Mw<8.0 was compiled from available local and regional monitoring stations.  Ground motions were classified based on the source type and converted to a common reference site condition.  The site-corrected motions were compared against alternative GMPEs to examine residual trends between observed and predicted amplitudes.  A backbone model that represents the best estimate of the median ground motions for each source type was selected.  The backbone models were then adjusted to the median of the ground motions observed at the study site.

The epistemic uncertainty in median predictions was modeled using a logic-tree approach, where the distribution of potential median predictions is approximated by a lower, central and upper model.  The central model is represented by the site-adjusted backbone model; it was scaled to define the lower and upper branches.  The scaling factor was determined considering: (i) the standard deviation in median prediction of alternative GMPEs; and (ii) epistemic uncertainties recommended in other studies.  The available data were insufficient to model aleatory variability with confidence; therefore, the standard deviation of observed motions in data-rich regions is used for guidance.  Two alternative aleatory variability models (ergodic and single-station sigma) adopted from other studies are recommended.
Eight Hundred Years of North Atlantic Jet Stream Variability and its Influence on European Climate Extremes
Authors: Trouet Valerie , Meko Matthew , Klippel Lara , Babst Flurin , Esper Jan , Krusic Paul , Panayotov Momchil , Wilson Rob
Published: March 2020

A recent increase in mid-latitude extreme weather events has been linked to anomalies in the position, strength, and waviness of the Northern Hemisphere polar jet stream. The latitudinal position of the North Atlantic Jet (NAJ) in particular drives climatic extremes over Europe, by controlling the location of the Atlantic storm track and by influencing the occurrence and duration of atmospheric blocking. To put recent NAJ trends in a historical perspective and to investigate non-linear relationships between jet stream position, mid-latitude extreme weather events, and anthropogenic climate change, long-term records of NAJ variability are needed. Here, we combine two tree-ring based summer temperature reconstructions from Scotland and from the Balkan Peninsula to reconstruct inter-annual variability in the latitudinal position of the summer NAJ back to 1200 CE. We find that over the past centuries, a northward summer NAJ position has resulted in heatwaves in northwestern Europe, whereas a southward position has promoted wildfires in southeastern Europe and floods in northwestern Europe. The great famine of 1315-1317 in northwestern Europe, for instance, was associated with prolonged flooding and cold summers that resulted in failed grain harvest and were related to a southern NAJ position. We further find an unprecedented increase in NAJ anomalies since the 1960s, which supports more sinuous jet stream patterns and quasi-resonant amplification as potential dynamic pathways for Arctic warming to influence midlatitude weather.
Climate change effects on UK shelf sea’s connectivity and hydrographic properties
Authors: Mayorga Adame Claudia Gabriela , Harle James , Holt Jason , Yuri Artioli , Wakelin Sarah
Published: March 2020

Climate change is expected to cause important changes in ocean physics, which will in turn have important effects on the marine ecosystems. The ReCICLE project (Resolving Climate Impacts on shelf and CoastaL seas Ecosystems) aims to identify and quantify the envelope of response to climate change of lower trophic level shelf-sea ecosystems and their functional interactions, in order to assess the vulnerability of ecosystem goods and services in the UK shelf seas. The central tool for this work is an ensemble of coupled hydrodynamic-biogeochemical ecosystem models NEMO-ERSEM Atlantic Margin Model configuration at 7 km horizontal resolution (AMM7), forced by different CIMP5 global climate change models to generate downscaled scenarios for future decades.

Changes in connectivity patterns are expected to affect coastal populations of marine organisms in shelf seas. Holt et al 2018 (GRL https://doi.org/10.1029/2018GL078878) showed the potential for radical reorganization of the North Sea circulation in earlier simulations. To assess this particular issue particle tracking experiments are carried out during two 10 year time slices, in the recent past (2000-2010) and in the future (2040-2050) in ensemble members of the ReCICLE AMM7 regional downscaling showing contrasting circulation patterns. Surface particles were uniformly seeded in the UK shelf seas every month and tracked for 30 days. The resulting particle trajectories are analysed with cluster analysis technics aiming to determine if persistent oceanographic boundaries re-arrange in the future climate scenarios. The ecological effects of circulation and water masses changes in the future ocean are discussed from a Lagrangian perspective.

 
A study on characteristics of movement of woody debris mass in debris flows by video footage analysis
Authors: Katayama Natsumi , Yamada Takashi
Published: March 2020

It is known that woody debris in a debris flow is concentrated near the flow front. However, the actual state of transportation of woody debris hasn’t been revealed. Accordingly, the purpose of our study is to clear characteristics of transportation of woody debris in debris flows by video footage analysis.

We collected and analyzed video footage of woody debris carried on debris flows and sediment flows. As a result, qualitative characteristics that woody debris was concentrated near the flow front and a lot of woody debris was carried on debris flows were revealed. In our study, the part of woody debris entangled by each other near the flow front is called “woody debris mass”. Woody debris that forms woody debris mass moved with little change in the relative position. When a sediment flow reached the widening part of stream channel and the flow was spread laterally, woody debris mass was broken down and the height of woody debris mass was reduced. Moreover, we measured stream channel width, velocity, flow depth, average length of woody debris, height of woody debris mass, and so on by using video footage. Consequently, a positive correlation was found between “the ratio of the average length of woody debris to the stream channel width” and “the height of woody debris mass”.

Besides, we carried out hydraulic flume experiment on the transportation of woody debris by debris flows. As a result, woody debris mass was formed near the flow front of debris flows. Furthermore, a positive correlation was found between “the ratio of the length of woody debris model to the flume width” and “the height of woody debris mass”. This result was harmonious with that of video footage analysis results.
Characterizing precipitation in convective cloud regimes in the trades with the polarimetric C-band radar POLDIRAD
Authors: Hagen Martin , Ewald Florian , Groß Silke , Li Qiang , Oswald Lothar , Tetoni Eleni
Published: March 2020

Low-level clouds in the trade regions play an important role in the Earth’s climate system since they have a considerable influence on the Earth’s radiation budget. However, the understanding of the coupling between cloud dynamics, cloud microphysics, and mesoscale organization is limited. This results in a large uncertainty in current climate predictions. Despite the importance, observations in these regions are limited. Geostationary satellites cannot provide high resolution three-dimensional details of clouds and precipitation. Polar orbiting satellites like the A-Train satellites Cloudsat and Calipso or the upcoming EarthCARE satellite do provide detailed profiles of cloud properties, but the temporal evolution cannot be observed. On the other hand, long range weather radar observations can provide both, high spatial and temporal observations, however not many weather radar do cover the trades.

During the Eurec4a campaign DLRs C-band polarimetric weather radar POLDIRAD was installed on the island of Barbados. The scope of the radar measurements is manifold:

- POLDIRAD will provide high resolution observations of the different mesoscale cloud patterns as observed from satellites: Flowers, Gravel, Fish, and Sugar. Will the mesoscale organization have an influence on observable microphysical properties?

- POLDIRAD will put the detailed measurements by aircraft (in situ and remote sensing) into a greater context. How are the aircraft measurements related to the spatial distribution of the precipitation pattern? How are the aircraft measurements related to the temporal evolution of the precipitation pattern?

- POLDIRAD will put the observed profiles of clouds and precipitation at the Barbados Cloud Observatory BCO at Deebles Point into a greater context. How are the profile measurements related to the spatial distribution of the precipitation pattern? How are the profile measurements related to the temporal evolution of the precipitation pattern?
Intelligent Extraction and Generation Technology of Emergency Plan
Authors: liu haiyang
Published: March 2020

Natural disasters will bring a huge threat to the safety of human life and property. When disasters happen, leaders at all levels need to respond in time. Emergency plans can be regarded as the effective guidance of natural disaster emergency responses, and they include the textual descriptions of emergency response processes in terms of natural language. In this paper, we propose an approach to automatically extract emergency response process models from Chinese emergency plans, and can automatically generate appropriate emergency plans. First, the emergency plan is represented as a text tree according to its layout markups and sentence-sequential relations. Then, process model elements, including four-level response condition formulas, executive roles, response tasks, and flow relations, are identified by rule-based approaches. An emergency response process tree is generated from both the text tree and extracted process model elements, and is transformed to an emergency response process that is modeled as business process modeling notation. Finally, when different disasters occur, a new plan is generated according to the training of historical plan database. A large number of experiments in the actual emergency plan show that this method can extract the emergency response process model, and can generate a suitable new plan.
Land management extends the duration of the impact of extreme on vegetation
Authors: Chen Tiexi
Published: March 2020

Extreme weather events have a severe impact on vegetation and the carbon cycle. It is generally believed that the vegetation will begin to recover immediately after the extremes, slowly or rapidly. This study will initially report a new response mechanism. We investigated a case of an extreme precipitation event that occurred in a double-cropping (DC) systems dominated region located Yangtze-Huai plain in China, where winter crops and summer crops are planted rotationally within one year. Generally October and June are the transitional periods for harvesting and sowing. In October 2016, monthly precipitation showed strong positive anomalies. Strong negative anomalies of EVI (enhanced vegetation index) persisted during March to May 2017, in response to the farmland abundance due to the heavy rain, especially over the farmland with winter crops – summer rice paddy systems. Information on abandonment due to precipitation also has been confirmed in local agro-meteorological monthly reports and some local government announcements. Data from a flux observation station in the region showed that from January to May 2017, NEE dropped significantly compared to the same period in 2016. Our results demonstrate that, in such a double-cropping system, once extreme events occur during the key sowing period and the phenological conditions determine that it cannot be replanted after, the duration of the impact will last through the entire crop growth period until the next sowing. In other word, land management could extend the duration of the impact of extremes on vegetation.
Analysis of the Response of Karst Spring to Precipitation in Longzici karst Area, Southern Shanxi province, China
Authors: Qiao Xiaojuan , Wang Dawei
Published: March 2020

In recent decades, the frequent occurrence of extreme weather events, coupled with the continuous increase in the intensity of artificial mining led to a general decline in the groundwater level in the karst areas of northern China. Some large springs even dried up.

Under the background of climate change, the analysis of spring water dynamic characteristics and its response to the atmospheric precipitation are of great significance to reveal the internal relation of groundwater system in karst spring area and the prediction and protection of spring water flow.

This paper selected a typical karst spring Longzici in southern Shanxi province as the object where the karst aquifer developed well. Based on the long time series precipitation monitoring and spring water flow data from 1987-2018, this paper analyzed the characteristics of spring and rainfall and found that they both have some periodicity. The precipitation has 2-3-year peak cycle and the annual average spring flow rate is 3.82 m3/s which had a dynamic fluctuation period of spring about 10 years. The result of regression model analysis of spring flow response to precipitation shows that the spring flow response has a time lag of four years to precipitation. It is most affected by its own spring flow in the previous year and different degrees affection of precipitation in the previous year and three years ago. It is also found that the sensitivity of spring flow to precipitation is influenced by precipitation amount. The effect of annual precipitation with abundant water and dry water on the flow rate of springs is with different delay length. The spring flow response to precipitation in the dry year is more pronounced. The trend analysis shows the groundwater in spring area is greatly influenced by spring own storage capacity and human exploitation.
Inception of a global atlas of Holocene sea levels
Authors: Khan Nicole , Ashe Erica , Kopp Robert , Horton Ben ,   HOLSEA working group
Published: March 2020

Determining the rates, mechanisms and geographic variability of sea-level change is a priority science question for the next decade of ocean research. To address these research priorities, the HOLocene SEA-level variability (HOLSEA) working group is developing the first standardized global synthesis of Holocene relative sea-level data to: (1) estimate the magnitudes and rates of global mean sea-level change during the Holocene; and (2) identify trends in spatial variability and decipher the processes responsible for geographic differences in relative sea-level change.

Here we present the efforts of the working group to compile the database, which includes over 12,000 sea-level index points and limiting data from a range of different indicators across seven continents from the Last Glacial Maximum to present. We follow a standard protocol that incorporates full consideration of vertical and temporal uncertainty for each sea-level index point, including uncertainties associated with the relationship of each indicator to past sea-level and the methods used to date each indicator. We highlight important challenges overcome to aggregate the standardized global synthesis, and discuss those that still remain. Finally. we apply a spatio-temporal empirical hierarchical statistical model to the database to estimate global sea-level variability and spatial patterns in relative sea level and its rates of change, and consider their driving mechanisms. Long-term, this effort will enhance predictions of 21st century sea-level rise, and provide a vital contribution to the assessment of natural hazards with respect to sea-level rise.
Modelling biophysically-defined, measurable soil organic matter with MEMS 2.0 model
Authors: zhang yao , Lavallee Jocelyn , Ogle Stephen , Paustian Keith , Cotrufo M. Francesca
Published: March 2020

Soil biogeochemical models have used conceptual soil organic matter (SOM) pools for decades. Recently, the MEMS 1.0 model has been developed which represents measurable biophysical SOM fractions and processes, embodying new understanding of the processes that govern SOM dynamics. We continue to develop the model and present here version 2.0. MEMS 2.0 is a full ecosystem model with modules simulating plant growth, soil water and temperature by layer, decomposition of litter and SOM, mineralization and immobilization of nitrogen. Unlike the older biogeochemical models (e.g. DayCent model) which simulate SOM only in the topsoil, MEMS 2.0 models the dynamics of SOM in every soil layer. We will present results from the calibration and testing of MEMS 2.0 using measurements from several grassland sites in the U.S, and discuss how modeling SOM as a particulate (POM) and mineral-associated (MAOM) pool better represents the formation, persistence, and functioning of SOM.
Multitemporal Monitoring of the Morphodynamics of a Meandering River by UAV-Based Measurements
Authors: Özcan Orkan , Akay Semih Sami , Şen Ömer Lütfi
Published: March 2020

Change detection analysis for monitoring and modeling riverine systems requires detailed spatiotemporal surveying of river morphology dynamics. An accurate high-resolution surface model of the river channel and floodplain enables a more comprehensive view of the riverbed evolution and allows monitoring the morphodynamics of the entire river channel more precisely compared to the traditional methods. Unmanned Aerial Vehicle (UAV) based Structure from Motion (SfM) techniques have renovated 3D topographic monitoring of earth surface, offering low-cost, rapid and reliable data acquisition and processing. Herein, the acquisition of repeated topographic surveys helps us to characterize the flow regime and to monitor the sediment dynamics. Multitemporal models of the river environment can be produced by autonomous operation to determine erosion, subsidence, landslide, soil transport and surface deformation in the riverbeds. The ‘meandering’ phenomenon takes its denomination from the Büyük Menderes River (BMR), which flows in a winding course in western Turkey, known as the Maiandros River in ancient times. Meandering rivers generally consist of a single, highly sinuous channel responding to erosion and sedimentation processes. This study presents the hydromorphological changes of the meandering structures by using multitemporal UAV surveys between 2017 and 2019 in the BMR. In the study, multitemporal topographic data were produced and morphodynamic processes in the lower course of the BMR were modelled by Digital Shoreline Analysis System (DSAS) and Digital Elevation Model of Difference (DoD) methods. These methods were employed to examine the changes in the shoreline and to analyse the size of geomorphological changes and spatial patterns. The results showed that the change in the shoreline of the meanders varied from 3 to 27 meters, and the water levels varied between approximately 0.3 and 3 meters. Although there was both sediment erosion and deposition along the shoreline, the predominant process was identified as deposition in the shoreline. Besides, major changes on the deposition rate were found to occur mostly after the summer season. Ultimately, a significant correlation was found between the deposited sediments and the sinuosity index values (r=0.88) according to the changes in water level over the months. This research showed that UAVs could provide a suitable measurement model for determining areal and volumetric eroded/deposited sediment quantities along the meandering fields.
Spectral Analysis of Solar Radio Type III Bursts from 10 kHz to 80 MHz
Authors: Sasikumar Raja Kantepalli , Maksimovic Milan , Bonnin Xavier , Zarka Philippe , Lamy Laurent , Kontar Eduard P. , Lecacheux Alain , Krupar Vratislav , Cecconi Baptiste , Lahmiti Nora , Denis Laurent
Published: March 2020

Solar radio type III bursts are produced by electron beams that are propagating along the open magnetic field lines in the corona and interplanetary medium (IPM). They are the intense, fast drifting, and frequently observed bursts. Recently, it was reported that observations of type III bursts show a maximum spectral response at around 1 MHz. But this behavior of type III bursts is not sufficiently discussed in the literature. In order to understand this behavior we have revisited this problem and studied 2279 isolated type III bursts that are observed with Wind/Waves instrument (from space during 1995-2009) in the frequency range 10 kHz-14 MHz and found that all of them show a maximum spectral response at around 1 MHz. Since type III bursts are somewhat directive, we have studied separately, another 115 type III bursts that are simultaneously observed (in 2013-2014) using Wind/Waves and ground-based facility Nancay Decameter Array (10-80 MHz) and compared the spectral profiles. In this presentation, we will discuss the observations, applied calibration techniques and the possible theoretical explanation of why type III bursts show such behavior. 