bluuebunny/crossref_metadata_2025 huggingface dataset:
Preview of the future application of the environmental geo-satellites data using aircraft platform: Estimation of anthropogenic VOC emissions from formaldehyde columns
Authors: Park Rokjin , Kwon Hyeong-Ahn , Oak Yujin
Published: March 2020

The Geostationary Environment Monitoring Spectrometer (GEMS) will be launched in February 2020 and will provide hourly observations of atmospheric compositions in the daytime. Prior to the GEMS launch, we explore an application of GEMS data as constraints for estimating anthropogenic volatile organic compound (AVOC) emissions in South Korea using formaldehyde (HCHO) vertical column densities observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) onboard the B200 aircraft during the KORUS-AQ campaign. Our top-down estimates of total AVOC emissions are higher by a factor of four over the petrochemical industries compared to the bottom-up emissions. However, the national AVOC emissions from the top-down estimates are by 37% lower than those of the bottom-up emission inventory in South Korea. We also show that hourly column observations of HCHO can improve not only the total magnitude of AVOC emissions but also their diurnal variation, which is poorly constrained and used in air quality models. Our hourly estimates of AVOC emissions may, thus, improve air quality model simulations in which the simulated ozone sensitivity to AVOC emission changes are also investigated.
Developing a highly-available GNSS reference station network
Authors: Ruddick Ryan , Peterson Amy , Jacka Richard , Thomas Bart
Published: March 2020

Having modern and well-maintained geodetic infrastructure is critical for the development of an accurate and reliable Global Geodetic Reference Frame (GGRF). Geoscience Australia (GA) contributes to the development of the GGRF through a network of Global Navigation Satellite System (GNSS) reference stations positioned in key locations across Australia, Antarctica and the Pacific. Data from these reference stations contribute to the realisation of the GGRF, the development and maintenance of the Asia-Pacific Reference frame and the monitoring of deformation across the Australian continent. We are also seeing a rapid increase in the use of this data for location-based positioning applications, such as civil engineering, transport, agriculture and community safety. These applications bring with them a new suite of challenges for geodetic infrastructure operators, such as reduced data latency, denser networks and accessing the latest signals in the most modern formats. Through the Positioning Australia program, GA is addressing these challenges by developing a modern highly-available GNSS reference station design that will be deployed at over 200 sites across the region. This paper discusses the concept of highly-available infrastructure and presents a GNSS reference station design that is openly available for use by the global geodetic community.
Neural Supermodeling
Authors: Wiegerinck Wim
Published: March 2020

Deep learning is a modeling approach that has shown impressive results in image processing and is arguably a promising tool for dealing with spatially extended complex systems such earth atmosphere with its visually interpretable patterns. A disadvantage of the neural network approach is that it typically requires an enormous amount of training data.

 

Another recently proposed modeling approach is supermodeling. In supermodeling it is assumed that a dynamical system – the truth – is modelled by a set of good but imperfect models. The idea is to improve model performance by dynamically combining imperfect models during the simulation. The resulting combination of models is called the supermodel. The combination strength has to be learned from data. However, since supermodels do not start from scratch, but make use of existing domain knowledge, they may learn from less data.

 

One of the ways to combine models is to define the tendencies of the supermodel as linear (weighted) combinations of the imperfect model tendencies. Several methods including linear regression have been proposed to optimize the weights.  However, the combination method might also be nonlinear. In this work we propose and explore a novel combination of deep learning and supermodeling, in which convolutional neural networks are used as tool to combine the predictions of the imperfect models.  The different supermodeling strategies are applied in simulations in a controlled environment with a three-level, quasi-geostrophic spectral model that serves as ground truth and perturbed models that serve as the imperfect models.
Melt inclusions in olivines from phoscorites and olivinites of the Kovdor massif.
Authors: Redina Anna , Wohlgemuth-Ueberwasser Cora , Mikhailova Julia , Ivanyuk Gregory
Published: March 2020

The Kovdor massif is a part of the Paleozoic Kola alkaline province and located in the eastern part of the Baltic Shield. Kovdor carbonatites host a unique complex baddeleyite-apatite-magnetite deposit from which iron ores and zirconium have been mined. New data on melt inclusions in olivine crystals from phoscorites and olivinites of the ore complex are presented in this contribution. Daughter minerals in crystallized melt inclusions were identified by Raman spectroscopy and scanning electron microscopy. The trace element composition of inclusions was determined using LA-ICP-MS.

Melt inclusions in olivine from Kovdor phoscorites are negative crystal or round in shape, with sizes ranging from 5 to 50 microns. They form groups or line up. According to the mineral composition, two types of melt inclusions can be distinguished: carbonate and silicate-carbonate. In the first type, Ca-Na-Mg- (Sr?) - REE carbonates are dominant among daughter phases. In the second one, silicate phases (phlogopite, monticellite, diopside), Ca-Na-Mg carbonates and magnetite are found together. Melt inclusions in olivine from olivinites are isometric or elongated, 5–25 μm in size. They form groups or occur as isolated inclusions. Benstoneite, geylussit, ankerite, calcite and hydroxyl-bastnesite along with phyllosilicates (phlogopite, paragonite?) were identified among daughter minerals.

The rare earth elements composition of melt inclusions from both types of rocks is characterized by the predominance of light REE. The content of REE, especially light ones, in inclusions from phoscorites is higher. Strontium and barium contents in most melt inclusions have negative correlations with niobium and zirconium concentrations.

Melt inclusions from phoscorites and olivinites contain carbonate and silicate mineral phases in various proportions, which may imply heterogeneous trapping of crystalline phases and two immiscible melts, silicate and carbonatite. Inclusions from phoscorite represent a more evolved magma with higher concentrations of rare metals.

This work was supported by the Russian Science Foundation, grant No 19-17-00013.
Parsing the DOM sources using calibrated biomarkers in the San Francisco Bay Estuary
Authors: Chuang Chia-Ying , Guillemette Francois , Harfmann Jennifer , Kaiser Karl , Spencer Robert , Bergamaschi Brian , Hernes Peter
Published: March 2020

The San Francisco Bay Estuary (SFBE) together with the Sacramento–San Joaquin River Delta is the second largest estuary in the United States and represents a highly dynamic ecosystem. From 2014 to 2016, we conducted three transects across a salinity gradient to investigate the roles of sources, hydrologic and seasonal changes on the DOM composition. Sampling started with a riverine endmember, through a vast area of marshes, wetlands, to the Golden Gate, the largest estuary in western North America. The winter transect at its maximum discharge allowed the study of DOM dynamics largely in the absence of photodegradation processes and low levels of algal production; the summer transect captured significant photodegradation and algal production; the spring transect revealed the signal of stored DOM from the snowmelt cold water flows. Multiple studies indicated that algal primary production alone cannot support the SFBE foodweb, and the wetlands could also serve to reduce DOM loadings coming off of the delta.  Hence, other sources of organic matter must be considered, including autochthonous and allochthonous DOM. Terrestrial DOM export in SFBE were revealed by dissolved lignin dynamics. Optical proxies (UV-vis and fluorescence) were also used to study the photochemical and biological transformations of DOM.
Observed Regional Sea Level Trends: Climate Drivers and Implications for Projecting Future Change
Authors: Nerem R. Steven , Fasullo John
Published: March 2020

The satellite altimeter record has provided an unprecedented climate data record for understanding sea level rise and has recently exceeded 27 years in length. This record of sea level change is becoming sufficiently long that we can begin to infer how sea level will change in the future. Results from Large Ensembles (LEs) of climate model simulations reveal that (a) the trend pattern of the Forced Response (FR) of sea level due to aerosols and Greenhouse gases (GHGs) is beginning to emerge from the altimeter record, (b) this pattern is likely to continue similarly for decades into the future, (c) the altimeter record falls during an interesting period when we are transitioning from an aerosol-dominated FR to a GHG dominated FR. All of these results provide clues into the causes of regional variations in the altimeter-observed regional trend pattern. In addition, these results suggest a possible path forward for performing short-term data-driven extrapolations of the satellite altimeter record to better understand future sea level change. We will review all of these results, show initial attempts at extrapolating the measurements, and discuss potential societal implications of the results.
Instantaneous rock transformations in the deep crust driven by reactive fluid flow
Authors: Beinlich Andreas , John Timm , Vrijmoed Johannes C. , Tominaga Masako , Magna Tomas , Podladchikov Yuri Y.
Published: March 2020

Fluid–rock interactions link mass and energy transfer with large-scale tectonic deformation, drive the formation of mineral deposits, carbon sequestration, and rheological changes of the lithosphere. While spatial evidence indicates that fluid–rock interactions operate on length scales ranging from the grain boundary to tectonic plates, the timescales of regional fluid–rock interactions remain essentially unconstrained, despite being critically important for quantifying the duration of fundamental geodynamic processes. Here we show that reaction-induced transiently high permeability significantly facilitates fast fluid flow through low-permeability rock of the mid-crust. Using observations from an exceptionally well-exposed fossil hydrothermal system to inform a multi-element advective–diffusive–reactive transport model, we show that fluid-driven reaction fronts propagate with ~10 cm year-1, equivalent to the fastest tectonic plate motion and mid-ocean ridge spreading rates. Consequently, in the presence of reactive fluids, large-scale fluid-mediated rock transformations in continental collision and subduction zones occur on timescales of tens of years, implying that natural carbon sequestration, ore deposit formation, and transient and long-term petrophysical changes of the crust proceed, from a geological perspective, instantaneously.
Microbial and abiotic interactions driven higher microbial anabolism on organic carbon accumulation during 2000 years of paddy soil development in the Yangtze River Delta, China
Authors: Bi Qingfang , Lin Xianyong , Wanek Wolfgang , Zhang Shasha , Canarini Alberto , Richter Andreas , Zhu Yong-Guan
Published: March 2020

Paddy soil as a major component of cropland, plays an important role in the global carbon (C) cycle and favors carbon sequestration especially in southern China. Soil microorganisms are central to the conversion of organic matter into SOC, yet the mechanisms underlying the paddy management at long time scales remain largely unknown, including microbial enzyme and functional potential kinetics, microbial growth and turnover. Here, using observations from a 2000-year-old paddy chronosequence since reclamation from tidal wetland at two different soil depths (0-20 cm and 20-50 cm) in the Yangtze River Delta, China, we show how paddy soil C sequestration is driven by the relationship between short-term responses in microbial physiology and long-term changes in biogeochemical soil properties. The samples were analyzed for nutrient pools, microbial biomass and growth, microbial activity and community composition, functional gene abundances, as well as microbially mediated nitrogen (N) cycling rate to determine how these microbial functionalities and processes affect microbial carbon use efficiency (CUE), an important indicator for microbial C sequestration. Across multiple time-scales ranging from decades to millennia, SOC in topsoil was increased by 65% during the first 50 years and reached the steady-state condition until 700-year, then was largely accumulated by 169% and 125% in 1000- and 2000-year, respectively, while C loss appeared in subsoil after 700 years of paddy cultivation. For topsoil and subsoil, microbial CUE reached to the highest values in 1000- and 700-year (0.46 and 0.36, respectively, while only 0.20 in the tidal wetland), along with microbial growth which both increased 5.2- and 3.3-fold in 1000-year, respectively. We found the similar increasing trends between microbial CUE and soil C:P and N:P ratios, the reduction of N limitation and functional potentials including N- and P-cycling, C degradation, C-fixation (acsA gene), microbial community homogenization and microbial biomass across soil chronosequence in topsoil. Moreover, the structural equation model revealed that with longer paddy management, the decline in soil pH had positive effects on microbial functional potentials and microbial biomass carbon. The enhanced functional potentials directly positively affected microbial growth, and thereby on microbial biomass carbon. Finally, the prolonged paddy cultivation increased SOC content via its direct positive effect and indirect positive influence on microbial biomass carbon. We conclude that longer paddy management captures the cumulative microbial anabolism on SOC sequestration in the plough layer, with the shifts in abiotic and biotic conditions towards increased nutrient availability and homogenous microbial community with higher functional potentials.
The improvement of water quality indicators in constructed wetland treatment systems in Latvia
Authors: Grinberga Linda , Lagzdins Ainis
Published: March 2020

This study includes water quality monitoring data obtained since June, 2014 at the farm located in the middle part of Latvia. The water treatment system with two separate constructed wetlands was established to improve water quality in agricultural area. A surface flow constructed wetland received drainage runoff from the agricultural catchment basin. A subsurface flow constructed wetland was implemented to retain nutrients from the surface runoff collected in the area of impermeable pavements of the farmyard. As there are no other specific calculations recommended for the designing of constructed wetlands in Latvia, both wetlands were calculated basing on the surface area of the constructed wetland/catchment area ratio. The surface area of the subsurface flow constructed wetland was deigned by 1.2% of the catchment area and the ratio was 0.5 % for the surface flow constructed wetland.

Water samples were collected manually by grab sampling method once or twice per month basing on a flowrate. Water quality parameters such as total suspended solids (TSS), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), total nitrogen (TN), orthophosphate-phosphorus (PO4-P), and total phosphorus (TP), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were analysed to monitor the performance of both wetlands. The concentrations at the inlet and outlet were compared to evaluate the efficiency of the water treatment.

The concentrations of NO3-N, NH4-N and TN were reduced on average by 21 %, 35 % and 20 %, respectively for the surface flow constructed wetland. PO4-P and TP concentrations were reduced on average by 31 % and 45 %, respectively for the surface flow constructed wetland. Total suspended solids were reduced by 17% at the outlet of the surface flow constructed wetland. However, in some cases, an increase in nutrient concentrations in water leaving the wetland was observed. The study showed the constant reduction of the PO4-P and TP concentrations 82 % and 83 %, respectively in the subsurface flow constructed wetland. The concentrations of NO3-N, NH4-N and TN were reduced on average by 14 %, 66 % and 53 %, respectively for the subsurface flow constructed wetland. BOD and COD reduction on average by 93 % and 83 %, respectively in for the subsurface flow constructed wetland indicated the ability of the treatment system to be adapted for wastewater treatment with high content of organic matter under the given climate conditions. This study outlined that the farmyards should receive a special attention regarding surface runoff management.
How deep do signals of surface conditions extend into the subsurface Critical Zone?
Authors: Trumbore Susan , Totsche Kai Uwe , Küsel Kirsten
Published: March 2020

Fluids (water and gases) connect surface and subsurface compartments of the Critical Zone by transporting matter, including chemical energy and organisms. In the AquaDiva Collaborative Research Center, one of our research goals is to use a variety of tracers to determine how the subsurface and the organisms inhabiting it reflect and depend on surface conditions.  This research is performed at the Hainich Critical Zone Exploratory (CZE), a hillslope transect in limestone and marlstone sedimentary rocks where a network of surface observations is linked to routinely monitored groundwater wells.   This CZE is especially interesting because its different rock units and hydrogeologic conditions create environments with different microbiomes and conditions.

This talk will synthesize information collected by AquaDiva researchers on how different kinds of ‘signals’ identify important mechanisms connecting surface and subsurface.   Biologically dominated signals, such as cell counts, metagenomics, metabolomics, the molecular composition and properties of dissolved organic matter,  change with distance from the surface.   While some individual compounds and organisms can be found across the different critical zone compartments, it is clear that that ground water and its inhabitants are not just diluted from the surface but reflect and co-evolve with microbial communities and subsurface environmental conditions.   Isotopic tools trace elements rather than chemical compounds and provide independent information on the timescales for surface-subsurface transport or the sources of energy or metabolites.  For example, we used bomb-radiocarbon as a tracer for surface carbon recently fixed by plants.  The 14C in dissolved or particulate organic matter and inorganic C demonstrate how newly fixed, recycled or even fossil (rock derived) C is incorporated into microbial food webs. Finally, surface conditions, including structure, influence the subsurface metabolism by regulating the transfer of electron acceptors like O2, excess nutrients from fertilizers, or reactive nanocrystalline Fe, through soils and unsaturated zones into groundwaters.  
Inlaid natural stones in Makrana Marble Taj Mausoleum of India
Authors: Kaur Gurmeet
Published: March 2020

Taj Mahal, the iconic mausoleum, known for finest quality white Makrana Marble from Rajasthan, is inlaid with numerous natural stones which add to the beauty of this architectural wonder from India. Makrana marble has been recently designated as a Global Heritage Stone Resource (GHSR) by IUGS. Makrana marble is the first GHSR from India and in fact the first from the whole of Asia to join the list of 22 designated GHSR’s from around the globe.

The Taj mausoleum is part of the Taj Mahal complex which has numerous edifices built in marble and red sandstone. The white Makrana Marble mausoleum is placed in the center of the northern periphery of the Complex. The main mausoleum is a magnificent octagonal edifice with its arched doorways, walls, floor adorned with intricate inlaid work in semi-precious natural stones and rocks that add an aesthetic dimension to this otherwise white marble edifice. The natural stones adorning the various components of the marble edifice include Yellow Jaisalmer Limestone, black slate, carnelian, agate, Khatu Rainbow Sandstone, onyx, lapis lazuli, malachite, jade, mother pearl, etc. The inlaid natural stones of Taj Mausoleum were procured from far off places during the Mughal rule in India.
Development of interconnected fine-grained polyphase networks during progressive exhumation of a shear zone
Authors: Lusk Alexander , Platt John
Published: March 2020

Present exposure of the ductile Caledonian retrowedge in northwestern Scotland records the evolution of a shear zone that was exhuming while actively deforming, providing a natural laboratory to study strain localization in a progressively cooling system. Examination of rocks from two detailed transects across this region consistently show a transition from microstructures that are dominated by interconnected phyllosilicate networks in a quartz-rich matrix with feldspar porphyroclasts, to interconnected fine-grained regions of mixed quartz + phyllosilicate + feldspar. These polyphase regions are demonstrably weaker than surrounding quartz layers and likely deform by grain-size sensitive mechanisms including diffusion-accommodated grain boundary sliding.

Microstructures characterized by a quartz-rich matrix and interconnected phyllosilicates undergo quartz recrystallization by high temperature grain boundary migration and are dominated by prism a slip. In contrast, fine-grained polyphase microstructures record quartz recrystallization dominated by subgrain rotation and activation of rhomb a and basal a slip systems. We propose transient hardening occurs in quartz-dominated regions as quartz with a strong Y-axis maximum undergoes the switch from prism a easy slip to basal a easy slip during cooling, and thus partitions strain into interconnected phyllosilicate layers. In response, interconnected phyllosilicate layers undergo mechanical comminution, becoming increasingly mixed by grain-size sensitive creep processes to form polyphase layers as they accommodate an increased proportion of strain. This transition from quartz-rich matrix with phyllosilicate interconnected weak layers to fine-grained, polyphase weak layers could be of first-order importance in strain localization within polyphase mylonitic and ultramylonitic rocks.
A characterization of microbial diversity in the Winter Wonderland Ice Cave, Uinta Mountains, Utah, USA
Authors: Seixas Miranda , Eggleston Erin , Munroe Jeffrey , Herron David
Published: March 2020

Winter Wonderland is an ice cave in the Uinta Mountains of northern Utah, USA. The cave, which has an entrance at 3140 m a.s.l., extends 245 m into a north facing cliff of Mississippi Madison Limestone. The cave was discovered by the U.S. Forest Service in 2014. Winter Wonderland Ice Cave likely originated in the Late Mississippian to Early Pennsylvanian when joints opened up in the vadose zone. The interior of the cave is perennially below freezing with ice covering sections of the floor to a thickness of at least 2 m. Seasonally, meltwater from the epikarst enters the cave, pools on the surface of the older ice and freezes, creating a layered ice mass containing organic matter dating back several centuries. As this water freezes, cryogenic cave carbonates (CCCs) precipitate and are incorporated in the ice. In this study, ice, water, and mineral precipitates in the cave were investigated for the presence of microorganisms adapted to this extreme environment. Samples were collected to investigate the microbial communities that may be present within the Winter Wonderland ice cave, identify what they are, and investigate whether the composition of the microbial community changes spatially within the cave and between sample types. An intact block of ice (18x10x10 cm), liquid water samples (n=8), and 13 CCC samples were collected in August 2019. The ice block was removed from a vertical exposure of ice at the back of the cave using a hand saw, water was collected from a pool on the ice surface, and the CCCs were sampled from the surface of the ice in multiple sections of the cave. The water samples were analyzed for stable isotope composition to better understand water source and freezing history. Crystallographic study of oriented slides cut from the ice revealed that the ice crystallized vertically with some variation in crystal size. All samples were also investigated with fluorescence microscopy, flow cytometry, and DNA sequencing to reveal the abundance and type of microorganisms. Preliminary fluorescence microscopy and SEM imaging reveals the presence of cocci and bacilli type microorganisms within water samples and ~10um wide eukaryotic organisms within the CCCs, suggesting that the CCCs may provide much needed nutrients for the microbes or that the CCCs themselves are products of biomineralization.
Evaluating the performance of CMIP6 models in the tropical Atlantic: mean state, variability, and remote impacts
Authors: Richter Ingo , Tokinaga Hiroki
Published: March 2020

General circulation models of the Coupled Model Intercomparison Project Phase 6 (CMIP6) are examined with respect to their ability to simulate the mean state and variability of the tropical Atlantic, as well as its linkage to the tropical Pacific. While, on average, mean state biases have improved little relative to the previous intercomparison (CMIP5), there are now a few models with very small biases. In particular the equatorial Atlantic warm SST and westerly wind biases are mostly eliminated in these models. Furthermore, interannual variability in the equatorial and subtropical Atlantic is quite realistic in a number of CMIP6 models, which suggests that they should be useful tools for understanding and predicting variability patterns. The evolution of equatorial Atlantic biases follows the same pattern as in previous model generations, with westerly wind biases during boreal spring preceding warm sea-surface temperature (SST) biases in the east during boreal summer. A substantial portion of the westerly wind bias exists already in atmosphere-only simulations forced with observed SST, suggesting an atmospheric origin. While variability is relatively realistic in many models, SSTs seem less responsive to wind forcing than observed, both on the equator and in the subtropics, possibly due to an excessively deep mixed layer originating in the oceanic component. Thus models with realistic SST amplitude tend to have excessive wind amplitude. The models with the smallest mean state biases all have relatively high resolution but there are also a few low-resolution models that perform similarly well, indicating that resolution is not the only way toward reducing tropical Atlantic biases. The results also show a relatively weak link between mean state biases and the quality of the simulated variability. The linkage to the tropical Pacific shows a wide range of behaviors across models, indicating the need for further model improvement.
Cyclogenesis and density currents in the Middle East and the associated dust activity in September 2015
Authors: Francis Diana , AlShamsi Noor , Cuesta Juan , Gokcen Isik Ayse , Dundar Cihan
Published: March 2020

The first 10 days of September 2015 were marked by an intense dust activity over the Middle East and the Arabian Peninsula. This study examines the atmospheric conditions at the origin of the large dust storms during this period. We particularly investigate the atmospheric dynamics leading to the development of a large dry cyclone over Iraq on 31 August 2015 which in turn generated an intense dust storm that affected most of the countries around the Arabian Gulf and lasted for 5 days. We found that the cyclone developed over Northwest Iraq as a transfer to low levels of a cut-off low which had formed two days earlier at upper levels over Turkey. Large dust loads exceeding 250 tons were emitted and moved southeast in a cyclonic shape toward the Arabian sea. The second large dust storm on 6-8 September 2015 occurred over Syria and affected all the coastal countries on the eastern side of the Mediterranean Sea. It was associated with the occurrence of a series of density currents over northeast Syria emanating from deep convection over the mountainous border between Syria and Turkey. The unusual development of deep convection over this area was associated with a blocking high and interaction with orography. Both the cut-off high and the cut-off low occurred during a period characterized by a meandering polar jet and an enhanced subtropical jet causing unstable weather over mid-latitudes which in turn led to highly polluted atmosphere by natural dust in the affected countries.
Keywords: Cut-off low; cut-off high; upper-level trough; density current; cyclone; evaporation cooling; desert areas; dust storms; polar jet; subtropical jet.
Plant Water Relation and Drought: Relationship Between Plant Water Potential and Relative Leaf Water Content in Different Tropical Plants
Authors: Kerman Sydney , Bailey Kinzie , van Haren Joost , Kübert Angelika , Kühnhammer Kathrin , Werner Christiane , Ladd Nemiah , Meredith Laura , Hu Jia
Published: March 2020

As global average temperature continues to increase and precipitation events become less predictable, understanding the long-term effects of drought on ecosystems is of increasing importance. However, it is difficult to study phenomena such as drought due to their unpredictable nature and the fact that it is difficult to tag and track the movement of water and carbon through an entire ecosystem. Within the framework of the controlled ecosystem manipulation experiment (WALD- Water, Atmosphere and Life Dynamics) at Biosphere 2, a deliberate drought in the enclosed tropical rainforest biome presented a unique opportunity to study responses in carbon and water cycling due to water stress. Within the scope of this study, the goal of this project was to examine the effect of prolonged water stress on different species within the rainforest and understand how the plants coped with the stress on an ecosystem level. This was accomplished by weekly plant water potential measurements (WP) before, during, and after the drought, as well as leaf sampling for relative leaf water content (RWC) and xylem sampling for water isotope measurements. For both predawn and midday WP, we found significantly different species responses; for Ceiba pentandra and Pachira aquatica, WP did not decrease during the drought, while for Hibiscus tiliaceus and Hibiscus rosa sinensis, WP decreased dramatically during the drought. After the additional of moisture from deeper depths, both C. pentandra and Hura crepitans (largest trees) responded the fastest by increasing in WP, while H. tiliaceus and H. rosa sinensis had the slowest recovery in WP, and only after rewetting from above had occurred. RWC also revealed different responses by different plant species, with Phytolacca dioica and H. rosa sinensis showing the highest RWC values throughout the experiment. The relationship between RWC and WP was also not consistent among species, with half of the species exhibiting a positive relationship, while the other half exhibiting a negative relationship. Other factors such as trunk capacitance and or leaf shedding during the drought might explain some of these contrasting relationships. Establishing such associations could lead to the development of tools that remotely assess average leaf water content of an area of forest via spectral reflectance and use those data to approximate the water stress of plants in that area, a very valuable asset when dealing with such geographically extensive phenomena as drought. 
Time variations of the temperature depth profile in a scientific-drilling borehole penetrated through the Futagawa Fault, Japan
Authors: Lin Weiren , Shibutani Susumu , Kamiya Nana , Sado Koichiro , Sugimoto Tatsuhiro , Yamamoto Yuzuru , Yang Xiaoqiu , Kinoshita Masataka
Published: March 2020

A scientific vertical borehole (borehole FDB) was rapidly drilled down to 691.7 m during September 2017 – March 2018 after the Mw 7.0 Kumamoto earthquake (mainshock), Japan occurred on 16th April 2016. This borehole penetrated the seismogenic fault called Futagawa Fault which ruptured during the mainshock. Temperature measurements across a newly ruptured fault enable us to detect the frictional heat induced by the high-speed fault slipping, and then to estimate the fault frictional resistance which controls earthquake dynamics. To investigate the frictional heat of its coseismic rupturing, we started temperature measurements in the borehole FDB from May 2018, i.e. two years after the mainshock. We are still repeating the temperature measurements once per two or three months; and have conducted seven times of the measurements until the end of November 2019.   

At the drilling site located at Mashiki town, Kumamoto Pref, a ~2.5 m dextral strike-slip coseismic displacement which is the largest displacement of the mainshock was observed on the surface rupture in this area. The borehole FDB consists of a cased interval from the surface down to a depth of ~300 m, and an open hole interval below that, down to the bottom of the borehole. In this borehole, the groundwater level is ~42 m, we measure the water temperature below the groundwater level and assume that the water temperature is the same as that of the formation after they became an equilibrium state after several months after the drilling operation. We measured the temperature and pressure while putting down and pulling up high resolution temperature and pressure sensors at an approximately constant rate of 3 m/min. A positive temperature peak around a fault where resistivity and P-wave velocity obtained from borehole logging abruptly dropped. The temperature depth profile showed time variation possibly including dissipation of the coseismic frictional heat caused by the fault rupturing and the other natural reasons e.g. groundwater flow.
Snow topography on undeformed Arctic sea ice captured by an idealized model
Authors: Popovic Predrag , Finkel Justin , Silber Mary , Abbot Dorian
Published: March 2020

Our ability to predict the future of Arctic sea ice is limited by ice's sensitivity to detailed surface conditions such as the distribution of snow and melt ponds. Snow on top of the ice decreases ice's thermal conductivity, increases its reflectivity, and provides a source of meltwater for melt ponds during summer that decrease the ice's albedo. Here, we develop a simple model of pre-melt ice surface topography that accurately describes snow cover on flat, undeformed ice. The model considers a surface that is a sum of randomly sized and placed ``snow dunes'' represented as Gaussian mounds. This model generalizes the "void model" of Popovic et al. (2018) and, as such, accurately describes the statistics of melt pond geometry. We test this model against detailed LiDAR measurements of the pre-melt snow topography. We show that the model snow-depth distribution is statistically indistinguishable from the measurements on flat ice, while small disagreement exists if the ice is deformed. We then use this model to determine analytic expressions for the conductive heat flux through the ice and for melt pond coverage evolution during an early stage of pond formation. We also formulate a criterion for ice to remain pond-free throughout the summer. Results from our model could be directly included in large-scale models, thereby improving our understanding of energy balance on sea ice and allowing for more reliable predictions of Arctic sea ice in a future climate. 
Classification of precursory weather patterns prior to high PM10 events over the Korean Peninsula
Authors: Ku Ho-young , Kim Baek-min , Choi Wonsik
Published: March 2020

In this study, we investigated precursory regional weather patterns prior to the high PM10 events over Korean Peninsula. The criterion for high-concentration PM10 events was set at 150 ug/m3 per day, referring to the “bad” among air environmental standards. In order to examine the regional weather pattern prior to the high PM10 events, the pressure fields of upper-level and lower-level were simply synthesized expecting the existence of clear signature of stagnant weather pattern. However, the resulting patterns were statistically insignificant around East Asia. We further investigated a possibility of existence of multiple precursory patterns partly offsetting each other.  Through the synoptic analysis of each case, we found that precursory weather patterns can be easily partitioned as two groups: 1) pre-existing persistent ridge and 2) Decaying east Asian cold-surge. In the case 1), persistent ridge embedded in an overall positive AO pattern sustains over East Asia both before and after the high PM10 event causing long-term accumulation of fine dusts over Korean Peninsula. In this case, warm surface temperature dominates before and after the high PM 10 event. In the case 2), upper-level trough over east Asia rapidly moves eastward along with cold-surge evolution and stagnant high pressure system sits in over Korean peninsula just after the timing of high PM event. Surface temperature suddenly changes from cold to warm dramatically.
Basic approaches to abatement of water pollution caused by non-point sources in the Volga river basin.
Authors: Polianin Vladislav , Kirpichnikova Natalia
Published: March 2020

The Volga River is the largest river in Europe and the main waterway of the western part of Russia. The total number of cases of high and extremely high pollution of surface waters in the river basin in 2016 and 2017 amounted to 988 and 939, respectively, which is about 30-35% of the total number of registered cases in the Russian Federation.
Traditionally the main factors affecting water quality are considered to be insufficiently treated industrial effluents and municipal sewage systems. In this regard, until recently, the regulatory actions of water protection in Russia have been the management of discharges and the reuse of wastewater, i.e. the management of point sources of pollution. However, despite some progress in that direction and the overall decline in wastewater discharges, partly as a result of the decline in industrial production, such a one-sided approach had not had the expected effect and, according to official statistics and reports, there had been no significant improvement in the ecological state of water bodies and in the quality of the Volga water. The recent research conducted by Water Problem Institute jointly with other leading Russian institutions and scientific organizations in 2018-19 within the framework of National project of rehabilitation of the Volga river has shown that such a situation took place mainly due to the lack of attention to non-point sources of pollution, particularly to agricultural activities, industrial sites, urban and suburban land development, landfills and areas of «accumulated environmental damage». 
These studies, as well as the synthesis of the results of surveys carried out within the Volga basin in previous years, show that the volume of pollutants such as oil products, organic substances, suspended solids, heavy metals (zinc, copper) from non-point sources exceeds (in some cases repeatedly) that of the point sources. For example, for the catchment area of the Upper Volga, it has been established that the amount of nitrogen and phosphorus coming from non-point sources is on average 45-55% of the total nutrient load, and for oil products and suspended substances this value can exceed 90%, especially during rainfall and spring flood events.
A general conception has been under developing and discussion to prevent further pollution of the Volga region including issues of monitoring, evaluation of diffuse loads, enhancing water protection programs and preventing negative effects of human activities at the scale of river catchments.
Five years of experimental summer drought – Anatomical and physiological acclimation of mature beech and spruce
Authors: Grams Thorsten
Published: March 2020

This contribution summarizes the outcome of a five-year experiment on mature (60-80 years old) trees in a Central European forest. We studied roughly 100 trees of European beech and Norway spruce, two tree species of contrasting foliage (i.e. deciduous vs. evergreen) and stomatal sensitivity to drought (i.e. anisohydric vs. isohydric behavior). Trees were exposed to experimentally induced summer droughts from 2014 to 2018 with precipitation throughfall being completely excluded during the growing seasons. The throughfall-exclusion study was established on 12 plots with trees readily accessible by canopy crane (Kranzberg forest roof experiment, southern Germany). We aimed at bringing trees to the edge of survival to studying trees’ capability for acclimation under repeated, severe summer droughts as expected more frequently in future climate scenarios. Results come from a multidisciplinary approach focusing on mechanisms of acclimation, eventually reducing trees’ vulnerability to drought during the five-year study period. Presented data integrate responses from the level of soil/microbial interactions over tree organs and whole-tree morphology to responses at the stand level.

During the first two years, restrictions caused by drought were most prominent, exemplified by pre-dawn leaf water potentials of down to -2.5 MPa and reductions in photosynthesis and growth by up to 50 and 80 % in European beech and Norway spruce, respectively. Nevertheless, percentage loss of conductivity in branch xylem was hardly affected. Likewise, concentrations of non-structural carbohydrates (sum of soluble sugars and starch) in tree organs remained largely unaffected, but translated to significantly lower carbohydrate pool sizes in view of strongly reduced tree growth. Nevertheless, two spruce trees died from drought, in the absence of bark beetle or pathogen interactions. During the fourth and fifth year of summer drought, trees showed clear signs of drought acclimation with e.g. some recovery of stomatal conductance, reductions of whole-tree leaf area, changes in rooting depth and acclimation of associated soil microbial communities. Accordingly, stem diameter growth recovered during the last years of the stress treatment, indicating reduced vulnerability of trees towards the end of the five-year drought treatment.
Climate Change Impact on Water Yield and Water Security in the Semi-arid Region of Rajasthan, India
Authors: Dubey Swatantra Kumar , Kumar Dr. Pankaj , Sharma Dr. Devesh , Dubey Aditya Kumar , Saharwardi Md. Saquib
Published: March 2020

The Soil and Water Assessment Tool (SWAT) model is a watershed-based hydrologic model for simulating water balance at the basin scale. The SWAT model delineates the watersheds and create the Hydrological Response Units (HRUs) in the different watersheds of the basin using Digital Elevation Model (DEM), Land use, Soil and slope, and gives the water balance of the River basin. In this study, the ensemble CORDEX-SA driving GCM experiment are used to predict the water balance of the basin in the historical and future periods under the RCP4.5 and RCP8.5 scenarios. The Banas River Basin is located into the semi-arid region of Rajasthan, covered 13 districts and 5 Agro-climate zones. The basin is divided into the four zones on the basis of Agro-climatic to predict the water yield and understand water security using per capita water availability and metrological variables. It is projected that the per capita water availability will decrease, and drought frequency will increase in the future period under different scenarios. Considering the par capita water availability and meteorological variation, all the four zones are ranked, and it is found that zone 3 is more water-secure compared to other zones in the present and future periods. This study may help to understand the water scarcity status in the basin under different climate change scenarios and need more focus to improve the water management issues at the basin level.
Assessment of Sediment Loss Reduction by Vegetated Ridge Using SWAT
Authors: Hong Jiyeong , Lee Dongjun , Kim Suhong , Kim Jonggun , Lim Kyoung Jae
Published: March 2020

Pollutants from the agricultural field are the main cause of water pollution in reach. Especially, in heavy rainfall seasons, non-point source pollutants from agricultural land contaminate stream with nitrogen, phosphorus, and other pollutants. To reduce the components of the contaminations that outflow from the agricultural areas, Best Management Practices (BMPs) have been installed. Integrated factors including weather, geographic characteristics and kind of crops should be considered for choosing proper BMPs in each field. In the fields which have long slope-length, the vegetated ridge is one of the best methods and wildly used method to reduce soil loss. In this study, the Soil & Water Assessment Tool (SWAT) was used to assess the effects of the vegetated ridge on streamflow and sediment within non-point source pollutant management areas. The LS factor in the modified Universal Soil Loss Equation (MUSLE) in SWAT was modified in order to simulate sediment loss reduction by the vegetated ridge in the target fields. This study aims to assess sediment loss reduction by implication of the vegetated ridge using SWAT and to propose the importance of vegetated ridge for reducing non-point source pollutants in agricultural fields. For further research, the development of a vegitated ridge application tool for SWAT will be conducted.
PI-COSMOS: An Open Source Python based High Speed Coastal Video Monitoring System
Authors: Madipally Ramesh , Nair L Sheela , Taborda Rui
Published: March 2020

In recent years, Coastal video monitoring methods have been widely accepted tools for continuous monitoring of complex coastal processes. In this paper, the progress made on a new python based coastal video monitoring system, PI-COSMOS (Portuguese Indian COaStal MOnitoring System) which is being developed and tested jointly in India and Portuguese coasts is presented. PI-COSMOS system aims at providing open source, high speed video monitoring toolboxes for the coastal community that can be used anywhere in the world. PI-COSMOS is camera independent system and comprises four modules viz. PI-Calib for camera calibration, RectiPI for video imagery rectification, PI-ImageStacks for image product and pixel product generation and PI- DB for efficient database management. The applicability of PICOSMOS system under different coastal environment conditions has been tested using the data collected from the India as well as the Portugal coast. The results from one of the Indian stations installed at Kozhikode beach, Kerala, India situated at 11°15'14.12" N, 75° 46'15.40" E are presented here to demonstrate the capabilities of the newly developed PI-COSMOS system. the performance of PI-COSMOS is evaluated by conducting a comparative study among PICOSMOS and existing video monitoring toolboxes like UAV processing toolbox provided by Coastal Research Imaging Network and RectifyExtreme provided by the University of Lisbon and it is found that the processing speed of PI-COSMOS is very much high i.e. more than 5 times when compared to UAV processing toolbox and RectifyExtreme.  The high speed performance, camera independent nature and easiness in the operation made PI-COSMOS as the simplest and advanced open source video monitoring system.

 