bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Last Reversal, Last Excursions and important HoloceneAnomalies of the Geomagnetic Field using the Eccentric Dipole and a 360-Dipole Ring Mode
Authors: González-López Alicia , Osete Maria Luisa , A. Campuzano Saioa , Rivera-Pérez Pablo , Molina-Cardín Alberto , Pavón-Carrasco F. Javier
Published: March 2022

Eccentric dipole can be considered the next approximation of the geomagnetic field after the
generally used geocentric dipole. Considering that during reversals, excursions and important
anomalies the non-dipole contributions are relevant, we study the evolution of the eccentric
dipole during the last reversal (Matuyama-Brunhes transition, ~780 ka), last excursions
(Laschamp, ~41 ka and Mono-Lake, ~34 ka), the Levantine Iron Age Anomaly (LIAA, ~1000 BC)
and the South Atlantic Anomaly (SAA, from 700 AD to present day) according to
paleoreconstructions (IMMAB4, LSMOD.2, SHAWQ-Iron Age and SHAWQ2k, respectively). In
order to get as much as information as possible from the eccentric dipole, we design a simple
model based on 360-point dipoles evenly distributed in a ring close to the Inner Core Boundary
that can be reversed and/or changed their magnitude. We calculate the evolution of the
modeled eccentric dipole according to the 360-dipole ring model reproducing the eccentric
dipole from the paleoreconstructions. If we consider that each point dipole could be associated
to convective columns in the outer core of the Earth, we can relate the evolution of the eccentric
dipole with potential variations in the outer core that cause its displacement. We observe that
the modeled eccentric dipole moves away from regions where dipoles start to reverse (which
are the cases for the reversal, excursions and the SAA) and towards regions where there are
anomalous high-moment dipoles (such as the LIAA). The results show that the eccentric dipole
paths during the events studied correlate well to Core Mantle Boundary low heat flux regions
that is consistent with the development of instabilities in the geomagnetic field.
Charge Separations in the Geomagnetosphere
Authors: Shen Chao , Gao Lai , Zhou Yufei , Ji Yong , Pu Zuyin , Russell Chris T. , Escoubet C. Philippe , Bogdanova Yulia V. , Zeng Gang , Torbert Roy , Burch Jame L.
Published: March 2022

Charges and electric currents source the electromagnetic field, and therefore the distribution and motions of charges determine its form. Charge separations may appear in various plasma boundary layers due to the inertia of electrons and ions or the trapping of the magnetic field. Based on the electric fields observed by MMS four spacecraft, the gradient of the electric field, as well as the charge density, can be obtained. The analysis on the electric field data acquired during dayside magnetopause crossing events by the MMS constellation shows a charge separation in the magnetopause boundary layer and that the positive charges are accumulated on the magnetospheric side while the negative charges are accumulated on the magnetosheath side. The charge separations in dayside, dawn side and dusk side magnetopause have been systematically explored. Furthermore, the spatial distribution of electric charge density in the inner magnetosphere is derived and analyzed based on the electric field measurements from September 2015 to December 2020 by MMS satellites. It is revealed that, the inner magnetosphere accumulates positive charge at dusk side and negative charge at dawn side, both of which vary with the magnetic activities. The charge and the electric field distribution confirm the presence of the Alfvén layer for the first time. In the Alfvén layer, the charge distribution has dawn-dusk asymmetry. The positive charge density at dusk is much greater than the negative charge density at dawn. These observations and analysis results could shed light on the structure of the magnetosphere and the magnetosphere-ionosphere coupling during storms.
Demonstrating the air-sea coupling performance of a Regional Earth System Model: Indian summer monsoon a case study
Authors: Kumar Pankaj , Mishra Alok Kumar , Sein Dmitry V.
Published: March 2022

An effort is made to implement a Regional Earth System Model (RESM) over the CORDEX-SA domain to demonstrate its skill in simulating the Indian summer monsoon characteristics. RESM was simulated on climate mode, 1980-2014, and showed good resemblance to observation in simulating mean precipitation, its variability (intraseasonal to interannual), extremes, and associated processes. RESM offers noticeable added value over its standalone atmospheric component (REMO), coupled model intercomparison project (CMIP5 and CMIP6), and regional climate models of CORDEX-SA. The added value is found to vary spatially. The most remarkable improvement is noticed over the Bay of Bengal (BoB), South-Central India, and Indo-Gangetic belt, where most standalone RCMs and coupled GCMs show limitations. The better representation of low-pressure systems both over land and ocean, sea surface temperature, Indian Ocean Dipole, and its underlying mechanism leads to improve mean precipitation. 

 

Keywords: RESM, CORDEX-SA, Indian summer monsoon, LPS, air-sea coupling

 

Acknowledgement: This work is jointly supported by the Department of Science and Technology (DST), Govt. of India, grant number DST/INT/RUS/RSF/P-33/G, and the Russian Science Foundation (Project No.: 19-47-02015).
On the global assessment of the coastal wave storminess
Authors: Lobeto Hector , Semedo Alvaro , Menendez Melisa , Lemos Gil , Ranasinghe Roshanka , Dastgheib Ali
Published: March 2022

Coastal storms represent powerful and damaging episodes involving climatic variables such as wind, precipitation, sea level and ocean wind waves. Particularly, ocean wind wave storms (or simply wave storms) have a high potential for coastal damage by acting as a major driver of impacts like shoreline erosion and flooding. Wave storms represent extreme wave events significantly exceeding the mean local wave climate conditions, hence impacting the coast by altering the mean equilibrium. This study assesses, for the first time, the global wave storminess based on a high resolution hindcast covering a 42-year period (1979-2020) with hourly time resolution, forced with wind fields from ERA5 reanalysis.

Here, wave events are classified as wave storms by using a unique global criterion based on exceedances over the 95th percentile of the significant wave height. This threshold is selected due to its widespread use in the scientific literature and its flexibility to adapt to local wave conditions, a basic requirement for working at global scale. Additionally, a minimum storm duration of 12 hours and a wave storm independence interval of 48 hours are considered to define the storms. For completeness, an independent analysis of the most severe wave storms reaching the coast is performed. For that matter, wave storms are classified as severe wave storms if the significant wave height exceeds the 99th percentile for more than 6 hours.  

The computation of several statistics and indices allows the analysis of the main characteristics of wave storms, such as frequency, duration and intensity. In addition, the mean significant wave height, mean wave direction and energy flux during wave storms are analyzed. Other secondary storm characteristics, such as swell and wind-sea dominance of the storm energy, and wave height and wave period dominance in the energy transport are also examined to complete the analysis. Results show a global coastal wave storminess pattern strongly characterized by a latitudinal gradient in which the coasts at higher latitudes are stormier than those at lower ones. The higher latitudes show the greatest mean wave heights during storms, reaching over 6 meters in western Ireland or southernmost Chile, and a high number of events per year. The tropical coasts are characterized by lower wave heights and longer storm durations, even exceeding 4 days in some stretches bordering the Arabian Sea. The most relevant exceptions to this behavior in the tropical region are the areas affected by TCs, which can be impacted by storms with very high wave heights.
Statistics of sea-effect snowfall in Finland based on ERA5 and FMIClimGrid
Authors: Olsson Taru , Luomaranta Anna , Jylhä Kirsti , Nyman Henri
Published: March 2022

Convective sea-effect snowfall (snow band) can develop in the Baltic Sea when cold air masses are advected from the mainland over a relatively warm open sea. Snow bands may last for several days over the Baltic Sea and, depending on the wind direction, move towards the Finnish coast. To investigate the spatial and temporal characteristics of snow bands in Finland and statistics of conditions favoring their formation, we used a set of detection criteria together with ERA5 reanalysis at a spatial grid spacing of 0.25° (~31 km) for a 48-year time period (1973–2020). Daily changes in snow depth over land areas were studied from FMIClimGrid gridded observational data. Only snow band cases when snow fell over the Finnish mainland was considered. Based on the ERA5 and FMIClimGrid data, we found on average 16 snow band days (SBD) per year. On average, the accumulated snow depths during SBD were moderate, daily mean varied between 2 cm/day to 5 cm/day in the studied regions along the coast of Finland. The largest daily mean snow accumulation (3.5–5 cm) during SBD was observed over the southern coast, but the largest daily snow depth increase (67 cm in January 2016) in the gridded data set was detected in the western coast of Finland. Neither the annual number of snow band days nor the daily snow accumulation revealed statistically significant changes due to large variations between years. The months of November and December showed the highest frequency of SBD. However, the seasonal cycle of SBD seemed to be shifting one month forward as the decrease in the number of SBD during December as well as the increase during January and February were statistically significant in Finland. The long-term changes in sea surface temperature (SST) and air temperature at atmospheric level of 850 hPa (T850) were in line with the changes in occurrence of SBDs. SST increased in all months during 1973–2020 in northern Baltic Sea. In December, when the decrease in snow band days was largest, also the T850 increased indicating less cold air masses occurring in Finland. So, even with increased SST the temperature difference favoring snow band formation might not reach the minimum threshold (13 °C) to produce snow bands due to too warm air temperatures. On the contrary, during January and February the increased SST together with no changes in T850 could favor the formation of snow bands.
Ion-scale transition of plasma turbulence: Pressure-strain effect
Authors: Hellinger Petr , Montagud-Camps Victor , Franci Luca , Matteini Lorenzo , Papini Emanuele , Verdini Andrea , Landi Simone
Published: March 2022

We investigate properties of solar-wind like plasma turbulence using direct numerical simulations. We analyze the transition from large (magnetohydrodynamic) scales to ion ones using two-dimensional hybrid (fluid electrons, kinetic ions) simulations of decaying turbulence. To quantify turbulence properties we apply spectral transfer and Karman-Howarth-Monin equations for extended compressible Hall MHD to the simulated results. The simulation results indicate that the transition from MHD to ion scales (the so called ion break) results from a combination of an onset of Hall physics and of an effective dissipation owing to the pressure-strain energy-exchange channel and resistivity. We discuss the simulation results in the context of the solar wind.
The evolution of early soil microstructure is governed by organic matter and its impact on the weathering rates of host rock
Authors: Ritschel Thomas , Aehnelt Michaela , Totsche Kai
Published: March 2022

Soil aggregation and the translocation of clay as well as organic matter are major processes of pedogenesis that manifest in the diagnostic soil horizons of mature soil. Yet, their onset might date to much earlier stages of soil development where host rock weathering is dominant and litter from pioneer vegetation is the only input of organic matter. To what extent aggregate formation is induced by early weathering and how clay transport facilitates aggregation is not yet comprehensively explored. Here, we present a time-lapse experiment on initial pedogenesis that reveals the formation of aggregates and clay translocation in response to irrigation with and without organic matter released from a litter layer. We show how organic matter increases total carbonate dissolution capacity with a characteristic surface morphology, but simultaneously slows down the dissolution rate. With the dissolution of carbonates, clay minerals of the host rock and iron from pyrite are released. Controlled by the presence of organic matter, both are either transported with the seepage water or form crusts and aggregates from clay minerals and freshly precipitated secondary iron oxides. The translocation and aggregation of organic matter and clay-sized minerals therefore shape soil structure already during initial pedogenesis and control the route in which soil development becomes apparent. 
Status and Plans for GPM and IMERG as They Enter Version 07
Authors: Huffman George , Braun Scott , Bolvin David , Nelkin Eric , Tan Jackson
Published: March 2022

As part of the “extended operations” past the 3-year prime mission, the Global Precipitation Measurement (GPM) mission continues to develop improved products, currently rolling out the next Version 07 datasets.  This is later than expected, due to unforeseen complications in upgrading algorithms.  Example upgrades include:  Complete data across the shift in scanning strategy by the Dual-frequency Precipitation Radar is now provided.  The Goddard Profiling (GPROF) algorithm is improved in regions where orographic enhancement and suppression take place, or where the surface is snowy/icy.  One key point is ensuring continuity across the boundary between the Tropical Rainfall Measuring Mission (TRMM) and of the GPM Core Observatory for each product.  As well, analyses by users have directly affected algorithm development.  Specifically, user research on precipitation features in the Integrated Multi-satellitE Retrievals for GPM (IMERG) led to findings on how the forward/backward morphing process and Kalman filter (KF) weighting distorts the Probability Density Function (PDF) of regional precipitation rates.  This insight has led to the Scheme for Histogram Adjustment with Ranked Precipitation Estimates in the Neighborhood (SHARPEN), a regional adjustment to the PDF of KF precipitation estimates.  In another initiative, the IMERG team worked with a user to develop the Histogram Anomaly Time Series analysis, providing a simple summary of the time series of anomalies in  the PDF of precipitation over a region, and revealing natural and input-based variations in precipitation. 

We will report the status of GPM Version 07 processing as of the conference time, and provide some examples of the changes in algorithm performance between Versions 06 and 07.
Estimation of the partial fluid composition after fluid-rock interaction: from mass balance calculations with an application to natural dolomitization
Authors: Centrella Stephen , Hoareau Guilhem , Beaudoin Nicolas E. , Motte Geoffrey , Lanari Pierre , Piccoli Francesca
Published: March 2022

Using the example of dolomitization where calcite is replaced by dolomite, estimation of the fluid composition in equilibrium with dolomite for major and trace elements was estimated based on EPMA and LA-ICP-MS data using a mass balance approach. The method consists in an analytical quantification of the mass transfer between the original calcite and the newly formed dolomite giving us which elements are coming in and out of the system. Chemical composition of the aqueous fluid in equilibrium with dolomite can be estimated such as the partition coefficient for each element involved in the reaction. This approach was tested using three existing datasets obtained from natural dolomite and original limestone in both Jurassic limestones of the Layens anticline in the Pyrenees (France), and two from the Middle Devonian Presqu’ile barrier from Pine Point (Canada). These are completed with data acquired in Cretaceous limestones of the Benicassim area of the Maestrat Basin (Spain). Using the result obtained with the mass balance calculation, the amount of fluid required to dolomitized a fixed amount of limestone can be obtained for different fluid source (brine and seawater). Results show that the four dolomitization reactions have similar solid volume variation (-14 to -10 vol.%) and the fluid in equilibrium with the dolomite have also similar concentration in trace element. Estimation of the partition coefficients for all trace elements for the three regions were determined and compared.
Accuracy of velocities from annually repeated GPS campaigns
Authors: Sanli D. Ugur , Uysal Ece , Oz Demir Deniz , Duman Huseyin
Published: March 2022

The determination of GPS velocity accuracy and velocity uncertainty has been one of the topics of interest to researchers in recent years. Velocity and velocity uncertainty from continuous GPS data have been studied as deeply as possible, but velocity and velocity uncertainty from campaign measurements are still the subject of ongoing research. Recent studies have shown that the positioning accuracy of GPS PPP is latitude-dependent. At the same time, the velocity and velocity uncertainty produced by the PPP should also be treated in the same way. In this sense, it is necessary to make a global assessment. NASA JPL offers researchers a rich global database constituting GNSS time series analysis results across the globe. In this study, an experiment is conducted to determine the velocity quality of GPS campaign measurements from around 30 globally distributed stations of the IGS network. This time, our motivation is to determine the accuracy and uncertainty of GPS campaign rates from at least 4 years of data, which are performed annually on the same date. As in our previous study, we decimated coordinate components from the NASA JPL time series to generate GPS campaigns. In other words, we use 24-hour data for annual campaign measurements and repeat campaigns on three consecutive days each year. The deformation rates from NASA JPL were considered real and the accuracy of the deformation rates produced by our experiments was evaluated. Preliminary findings suggest that velocity deviations from the truth may be more severe, at 4 mm/year horizontally and 10 mm/year vertically. In the presentation, we discuss the ground truths that lead to this bias and the global distribution of velocity accuracy and velocity uncertainty.
The role of soil moisture information in developing robust climate services for smallholder farmers: evidence from Ghana 
Authors: Paparrizos Spyridon , Sutanto Samuel , Jamaldeen Baba M. , Issahaku Abdulai Kantunsong , Kranjac-Berisavljevic Gordana , Gandaa Bizoola Z. , Nauta Lisanne , Supit Iwan , van Slobbe Erik
Published: March 2022

In Ghana, most of the farmers are engaged in small-scale rainfed farming where the success is influenced by how the farmers are able to march their decisions to the prevailing weather conditions. Climate information services (CIS), which includes weather forecasts, can help farmers to reduce their vulnerability to climate extremes and allow them to maximize agricultural productivity. Current services in Ghana and elsewhere in the world, however, only provides information on the recent and forecasted meteorological variables, primarily precipitation and temperature. Having access to other practical knowledge, such as soil moisture content would help farmers further in the decision-making process. Soil moisture is a key component for better farm management practices, because the plant establishment and growth are directly impacted by the soil moisture content. Therefore, this study aims to assess the importance of soil moisture information in farmers’ agricultural decision-making and to understand how this information is being perceived, assessed, and applied. An exploratory research, combined with field visits, farmer interviews, including questionnaires, and focus group discussions was carried out in three local farming communities i.e. Gbulung, Napakzoo, and Yapalsi in the outskirts of Tamale, northern Ghana. Results show that farmers clearly understand the importance of soil moisture for agriculture decision-making in every farming stages. Many farmers expressed that soil moisture information is highly important for fertilizer application and sowing. This information, however, is not well received by the farmers, causing farmers to rely on their indigenous knowledge to monitor the soil moisture conditions. Soil moisture forecast is ranked as the second critical information for farmers after precipitation. Capacity building and frequent interactions at farmer field schools and trainings could increase the farmer’s understanding and awareness of the role of soil moisture in agricultural decision-making. Moreover, farmers show an interest in a CIS embedded with a soil moisture forecast advisory module (CIS-SM) that could help them to increase the water-use efficiency and in the end, reduce the pressure on available water resources for agriculture.
Regional differences in cyclone impacts on Arctic sea ice concentration during winter
Authors: Aue Lars , Akperov Mirseid , Uotila Petteri , Vihma Timo , Rinke Annette
Published: March 2022

Cyclone events in the Arctic strongly affect both atmospheric variables, such as wind, air temperature and clouds, and surface variables, including sea ice concentration (SIC) and turbulent heat fluxes. However, despite the progress via recent statistical studies, the overall impact of cyclones on Arctic weather, sea ice, and feedback processes between them is not quantitatively well known.

In this study we built up on previous publications and present further details on cyclone impacts on Arctic sea ice in winter by covering a wider range of timescales than before and evaluating our results separately for three different marginal seas of the Arctic Ocean. Hereby we make use of the ERA5 reanalysis and a storm tracking algorithm to analyze the temporal evolution of SIC up to two weeks around the occurrence of each cyclone and compare it with a non-cyclone reference state.

The results show an initial decrease in SIC associated with the occurrence of a cyclone for the Barents and Kara Seas, which is balanced by an increase during the following days. On the contrary, in the Greenland Sea SIC remains lower after a cyclone event for the whole analyzed time period. For all the marginal seas considered, the impact of cyclones on sea ice is intensified, if SIC at a grid cell is low and if the intensity of a cyclone is high. Ongoing work consists of providing more details about the mechanisms responsible for the identified regional differences in cyclone influence on sea ice.
Seasonal and regional pH variation determined from continuous spectrophotometric measurements on a ship of opportunity in a coastal region
Authors: M. Lencina-Avila Jannine , Müller Jens Daniel , Otto Stefan , Glockzin Michael , Sadkowiak Bernd , Rehder Gregor
Published: March 2022

Coastal regions are under the threat of surface water acidification, which its ecological and socioeconomic impacts need to be better constrained. However, pH measurements in coastal waters are challenging and are still primarily measured discretely, compromising spatial or temporal scales. Therefore, directly measuring an acidification parameter, such as pH, with high spatial and temporal coverage could improve our understanding of the changes in the water acid-base balance and, thus, potential changes in the biogeochemical processes in these highly dynamic regions. Contributing to coastal management, we analysed continuous surface spectrophotometric pH measured on board the Ship of Opportunity "Finnmaid" along the Baltic Sea over the year 2020. We observed a pronounced seasonality of isothermal (25 oC) pH (total scale, pHT), with higher pH values in warm seasons (8.206 ± 0.148) and lower in colder seasons (7.959 ± 0.065), with maximum (8.792) and minimum (6.971) pH observed in the Gulf of Finnland during the summer. Consistently, surface pCO2 mirrored pH, with general averages of 299.6 ± 103.5 µatm (spring) and 279.4 ± 108.0 µatm (summer). In addition, the high-frequency measurements enable us to investigate biogeochemical processes at the submesoscale and, thus, better resolve sub-basin and sporadic coastal processes, such as river discharge and upwelling events. For this purpose, the Baltic Sea was sub-dived into three basins along the ship track: the German coast, the Gotland Sea, and the Gulf of Finland. Data in the Gulf of Finland indicated higher biological productivity during the warm season (spring-summer), depicted by a more significant surface pCO2 drawdown (minimum of 181.2 µatm) compared to the Gotland Sea (237.3 µatm) and German coast (200.8 µatm) minima. Consequently, pH values followed this pattern, reaching maxima of 8.792, 8.433, and 8.562 in summer, respectively. The results indicate that seasonal pH variations are controlled mainly by biological processes, which, in turn, vary regionally due to differences in the external conditions (e.g., light availability), the hydrographical setting (e.g., temperature and water column structure) and nutrient availability. Furthermore, the high spatiotemporal resolution of pH measurements achieved here allows for tracking the minimum and maximum pH values encountered in the surface water over the entire year, which can support current efforts towards the development of an acidification indicator within HELCOM.
Rate my Hydrograph: Evaluating the Conformity of Expert Judgment and Quantitative Metrics
Authors: Gauch Martin , Kratzert Frederik , Mai Juliane , Tolson Bryan , Nearing Grey , Gupta Hoshin , Hochreiter Sepp , Klotz Daniel
Published: March 2022

As hydrologists, we pride ourselves on being able to identify deficiencies of a hydrologic model by looking at its runoff simulations. Generally, one of the first questions that a practicing hydrologist always asks when presented with a new model is: "show me some hydrographs!". Everyone has an intuition about how a "real" (i.e., observed) hydrograph should behave [1, 2]. Although there exists a large suite of summary metrics that measure differences between simulated and observed hydrographs, those metrics do not always fully account for our professional intuition about what constitutes an adequate hydrological prediction (perhaps because metrics typically aggregate over many aspects of model performance). To us, this suggests that either (a) there is potential to improve existing metrics to conform better with expert intuition, or (b) our expert intuition is overvalued and we should focus more on metrics, or (c) a bit of both.

In the social study proposed here, we aim to address this issue in a data-driven fashion: We will ask experts to access a website where they are tasked to compare two unlabeled hydrographs (at the same time) against an observed hydrograph, and to decide which of the unlabeled ones they think matches the observations better. Together with information about the experts’ background expertise, the collected responses should help paint a more nuanced picture of the aspects of hydrograph behavior that different members of the community consider important. This should provide valuable information that may enable us to derive new (and hopefully better) model performance metrics in a data-driven fashion directly from human ratings.

 

[1] Crochemore, Louise, et al. "Comparing expert judgement and numerical criteria for hydrograph evaluation." Hydrological sciences journal 60.3 (2015): 402-423.

[2] Wesemann, Johannes, et al. "Man vs. Machine: An interactive poll to evaluate hydrological model performance of a manual and an automatic calibration." EGU General Assembly Conference Abstracts. 2017.
Laser Ablation - ICP-MS measurements for high resolution chemical ice core analysis with a first application to an ice core from Skytrain Ice Rise (Antarctica) 
Authors: Hoffmann Helene , Day Jason , Rhodes Rachael , Grieman Mackenzie , Humby Jack , Rowell Isobel , Nehrbass-Ahles Christoph , Mulvaney Robert , Thomas Elizabeth , Gibson Sally , Wolff Eric
Published: March 2022

The ice in the deepest and therefore oldest parts of polar ice cores is highly compressed. Annual layers, although potentially preserved, can be thinned to a millimeter scale or even below. However, for many palaeoclimate studies these are the most interesting sections. Within the WACSWAIN (WArm Climate Stability of the West Antarctic ice sheet in the last Interglacial) project we aim to investigate particularly the basal part of an ice core recently drilled to bedrock at the Skytrain Ice Rise in West Antarctica. Our aim is to obtain unique information on the state of the Filchner-Ronne ice shelf during the last interglacial (LIG). To achieve this we have set up a system to perform using high-resolution laser-ablation inductively coupled plasma – mass spectrometry (LA-ICP-MS) measurements using a cryocell stage on selected segments of the ice core. Here we present first results of system performance including assessment of measurement sensitivity and precision with respect to analyses of the most relevant components, including sodium, magnesium, calcium and aluminium. We report on the sample preparation technique as well as the resulting process blank. We evaluate the horizontal variability of the LA-ICP-MS signal across the ice core and the representativity of the high-resolution signal for an overall impurity content for different depth levels in the core. The results of the laser ablation ICP-MS measurements are then compared to low-resolution chemistry data from continuous flow analysis of the Skytrain ice core performed on the ice from the same depth. This comparison aims to evaluate the capabilities of the method in terms of improving depth resolution and annual variability. In a first application, sections of 80cm of ice from five different depth intervals covering time frames from late Holocene to the LIG are analysed via LA-ICP-MS and compared for their overall impurity content as well their signal variability. Finally, the potential of the method for resolving annual layers and fast changing climate signals within the core section covering the time period of the late last interglacial (about 115 - 120 ky before present) is investigated.
Soil moisture probes for mobile irrigation machines
Authors: Kafarski Marcin , Jacek Majcher , Andrzej Wilczek , Agnieszka Szypłowska , Arkadiusz Lewandowski , Wojciech Skierucha
Published: March 2022

The necessity of saving water is a very important issue in precision agriculture. It requires soil moisture monitoring of very large field areas. Soil moisture maps obtained in real time are very useful for proper and economic irrigation.

The soil moisture sensor market is very large. Sensors differ in accuracy, price, measurement speed, etc. However, typical soil moisture sensors are designed for fixed installation or manual insertion. The aim of this work was to present sensors which have high accuracy, high speed of measurement and high mechanical strength required for field mapping performed by an automated platform, which makes hundreds or thousands measurements at a given field. In addition to the aforementioned properties, the sensors should have a big sensitivity zone, which would minimize the impact of air gaps, stones, roots and soil local heterogeneity on moisture measurement results. The presented results involve the design of the sensors and laboratory verification of their performance.

Acknowledgments: The research was supported by the Polish National Agency for Academic Exchange under Grant no. PPI/APM/2018/1/00048/U/001.
An automatic oil spill detection and early warning system in the Southeastern Mediterranean Sea
Authors: Yang Yi-Jie , Singha Suman , Goldman Ron
Published: March 2022

Oil pollution is one of the most serious marine contamination; deliberate illegal discharges and tanker accidents pose threats to marine wildlife. The oil pollution “hotspots” are usually related to the regions with high marine traffic. One example would be the Eastern Mediterranean Sea as it offers the shortest shipping route from Asia to Europe and is regarded as an oil transit center. In addition, the discovery of oil and gas in the Levantine basin has led to an increasing number of oil and gas exploration and exploitation activities. However, there is no automated service exists for the region that provides early warning for oil spills along with projected forecast. This contributed to late reactions to an oil spill incident on February 2021, which caused a large ecological impact at the coast of Israel. This study aims to provide an automatic oil slick detection system and its integration to an early warning system for oil drift simulation in the Southeastern Mediterranean Sea. This can help with the estimation of oil contaminating region and the planning of oil combating response. The system includes both oil slick detection and oil drift simulation.

With the advantages of wide coverage and all-weather observations, Synthetic Aperture Radar (SAR) is applied for detecting oil spills. Sentinel-1 SAR Level-1 Ground Range Detected (GRD) products are downloaded from Copernicus Open Access Hub. The SAR products are then preprocessed with corrections including border noise removal, thermal noise removal, calibration, ellipsoid correction and conversion to decibels (dB) in a series of programs with the use of the Sentinel Application Platform (SNAP) Python API. Afterwards, a mosaic of showing the latest results from different preprocessed scenes in the study area is generated. A trained deep learning based You Only Look Once version 4 (YOLOv4) object detector is then used to detect oil spills on the mosaic results; the detector was trained on a total of 9768 manually inspected oil objects collect from 5930 Sentinel-1 images from 2015 to 2018. The extents of the detected oil slicks are defined by bounding boxes. Thus, the segmentation method is then applied to obtain the exact area covered by oil. The output oil slick masks are subsequently used for the simulations of oil slick trajectory by the MEDSLIK model, which uses daily forecasts of wind, circulation and wave to compute the propagation of the slick. An online interface is provided to perform simulations and visualize the results. In summary, the oil slick detection system notifies the decision makers of the existence of oil spills, and at the same time passes the generated oil slick masks to the early warning system for simulating their trajectories in order to help with the planning of response. A prototype of the integration of automatic oil spill detection and early warning system will be shown in the presentation. 

 
Statistical methodology for PRV malfunction detection and alerting in Water Distribution Networks 
Authors: Perdios Anastasios , Kokosalakis George , Karathanasi Irene , Langousis Andreas
Published: March 2022

As the outflow velocity from a pipe crack increases with increasing hydraulic pressure, pressure management concepts have been widely applied to reduce water losses in the delivering and distribution parts of water networks. In this context, pressure reducing valves (PRVs) have been commonly used to regulate pressures and therefore reduce water losses, in both water supply and water distribution networks, by reducing the upstream pressure to a set outlet pressure (i.e. downstream of the PRV), usually referred to as set point.

As all types of mechanical equipment, PRVs exhibit malfunctions affecting pressure regulation, which can be defined as events when the outlet pressure does not match the set point. These events can be classified in two categories: a) high frequency fluctuations around the set point, and b) prolonged systematic deviations from the set point. Since PRV malfunctions result in systematic or random deviations of the outlet pressure from the set point, their detection can be approached in a statistical context.

In this study, we develop a novel framework for detection of PRV malfunctions in water supply and water distribution networks, which uses: a) the root mean squared error (RMSE) as a proper statistical metric for monitoring the performance of a PRV by detecting individual malfunctions (i.e. malfunction occurrences) in the high-resolution pressure time series, and b) the hazard function concept to identify a proper duration of sequential events from (a) to issue alerts.

The suggested methodology is implemented using pressure data at 1-min temporal resolution from pressure management area “Diagora” of the water distribution network of the city of Patras (the third largest city in Greece), for a 3 year period from 01 January 2017 to 31 December 2019. The obtained results show that the developed statistical approach effectively detects major PRV malfunctions (as reported by the Municipal Water Supply Company and Sewerage of Patras, DEYAP), allowing it to be used for operational purposes.

Acknowledgments:

This research is co‐financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: T2EDK-4177).
Reconstructing the Atlantic Meridional Overturning Circulation in Earth System Model simulations from density information using explainable machine learning
Authors: Mayer Björn , Barnes Elizabeth , Marotzke Jochem , Baehr Johanna
Published: March 2022

Despite the importance of the Atlantic Meridional Overturning Circulation (AMOC) to the climate on decadal and multidecadal timescales, Earth System Models (ESM) exhibit large differences in their estimation of the amplitude and spectrum of its variability. In addition, observational data is sparse and before the onset of the current century, many reconstructions of the AMOC rely on linear relationships to the more readily observed surface properties of the Atlantic rather than the less explored deeper ocean. Yet, it is conceptually well established that the density distribution is dynamically closely related to the AMOC, and in this contribution, we investigate this connection in model simulations to identify which density information is necessary to reconstruct the AMOC. We chose to establish these links in a data-driven approach. 

We use simulations from a historically forced large ensemble as well as abruptly forced long term simulations with varying strength of forcing and therefore comprising vastly different states of the AMOC. In a first step, we train uncertainty-aware neural networks to infer the state of the AMOC from the density information at different layers in the North Atlantic. In a second step, we compare the performance of the trained neural networks across depth and with their linear counterparts in simulations that were not part of the training process. Finally, we investigate how the networks arrived at their specific prediction using Layer-Wise-Relevance Propagation (LRP), a recently developed technique that propagates relevance backwards through the network to the input density field, effectively filtering out important from unimportant information and identifying regions of high relevance for the reconstruction of the AMOC.

Our preliminary results show that in general, the information provided by only one density layer between the surface and 1100 m is sufficient to reconstruct the AMOC with high precision, and neural networks are capable of generalizing to unseen simulations. From the set of these neural networks trained on different layers, we choose the surface layer as well as one subsurface layer close to 1000 m for further investigation of their decision-making process using LRP. Our preliminary investigation reveals that the LRP in the subsurface layer identifies regions of potentially high physical relevance for the AMOC. By contrast, the regions identified in the surface layer show little physical relevance for the AMOC.
Chronometry of a nappe-scale thermal event inferred by thermobarometry and viscous relaxation of quartz inclusion pressure (Adula nappe, Alps)
Authors: Zhong Xin , Germer Marisa , Pohl Alexandra , Könemann Vincent , Brunsmann Olga , Groß Philip , Pleuger Jan , John Timm
Published: March 2022

The Adula nappe is located at the eastern flank of the Lepontine dome in the Swiss Alps. It consists mainly of orthogneiss and paragneiss with intercalated lenses of eclogite, amphibolite and metasediments. Previous petrological studies on the peak pressure and temperature (P-T) conditions yield somewhat inconsistent results, particularly the pressure in the southern part of the nappe, but in general exhibit an increasing trend in both P-T towards the south. In this work, we applied zirconium-in-rutile thermometer and quartz-in-garnet Raman elastic barometer to constrain the P-T conditions using samples covering most of the nappe with high spatial coverage within the 600 km2 area to obtain an internally consistent dataset. Based on the results of zirconium-in-rutile thermometer, the temperature gradually increases from the north at ca. 540 °C to the south at ca. 680 °C. Using the quartz-in-garnet elastic barometer, the calculated entrapment pressure increases from ca. 2.0 GPa to ca. 2.2 GPa from the north to the middle-south region of the Adula nappe, but rapidly falls to ca. 0.8-1.2 GPa towards the southern region, where the temperature exceeds ca. 650 °C. It is speculated that due to the temperature increase towards the south, viscous relaxation became activated that led to an apparent drop of the recorded residual quartz inclusion pressure. This suggests that by applying a pure elastic model to high temperature conditions, one may potentially underestimate of the formation pressure of garnets. Therefore, this study may provide information on the limit of the quartz-in-garnet (pure) elastic barometry technique. Moreover, it may offer a potential opportunity to constrain the duration of the near-isothermal decompression path if a viscoelastic model can be applied, which requires not only the equation of state of minerals but also the creep behavior of the inclusion-host system.
Implementation of Climate Forcings (volcanic, orbital, solar, LUC, GHG) for Paleoclimate Simulations (500BCE-2000CE) in the COSMO-CLM
Authors: Hartmann Eva , Zhang Mingyue , Xoplaki Elena , Wagner Sebastian , Adakudlu Muralidhar
Published: March 2022

The climate of the last 2500 years is documented in natural (speleothems, tree rings, sediments and pollen) and human-historical archives. Proxy records and subsequent climate reconstructions can be subject to a considerable amount of uncertainty, as the proxies can only capture a fraction of the entire variability. Climate model simulations can contribute to the interpretation of variations observed in the paleoclimate data and better understanding of dynamics, mechanisms and procedures. The state-of-the-art simulations following the CMIP6-protocol are highly resolved in time but still present a rather coarse horizontal resolution (200 km or more) to adequately address regional paleoclimate questions/hypotheses. Dynamical downscaling can close the gap between the regional archives and the coarsely resolved Earth System Models (ESMs). Using regional climate models to downscale ESM output requires a consistent implementation of the climate forcings in the regional model used also for the driving ESM. State-of-the-art and CMIP6 compliant reconstructions of volcanic (stratospheric aerosol optical depth), orbital (eccentricity, obliquity, precession), solar (irradiance), land-use and greenhouse-gas changes used for the MPI-ESM are therefore implemented in the regional climate model COSMO-CLM (CCLM, COSMO 5.0 clm16). The functionality of each implemented forcing is tested separately and in combination for the period (1255-1265) that covers the Samalas volcanic eruption of 1257. The orbital forcing is found to have the largest impact in general and the volcanic forcing has a strong but short-lasting effect after the eruption. The other climate forcings only show very small impact in the chosen period. At the moment, a transient CCLM simulation with all forcings implemented with a horizontal resolution of 50 km is running for the last 2500 years in the Eastern Mediterranean, the Middle East and the Nile River basin.
Revamping FLEXPART for the next generation of simulations
Authors: Bakels Lucie , Baier Katharina , Bucci Silvia , Dütsch Marina , Plach Andreas , Tatsii Daria , Vojta Martin , Stohl Andreas
Published: March 2022

The Lagrangian atmospheric transport model, FLEXPART, is used to investigate a broad spectrum of topics within the atmospheric sciences, from the propagation of particles emitted during nuclear accidents to global moisture transport. Since its inception in 1998, FLEXPART has undergone many changes, with its last official release (version 10.4) published in 2019. At the same time, numerous versions have been developed across institutes to cater to various needs. To make it easier to modify FLEXPART, while not having to diverge from the main version and its updates, we introduce a more modular way of organising the source code. Running times are improved by consistent OpenMP parallelisation in all parts of the code, resulting in reasonable scaling behaviour. Alongside the restructuring of FLEXPART, other improvements have been made. For instance, the interpolation errors have been reduced by replacing the traditional FLEXPART-internal terrain-following coordinate system with the option of doing all calculations on the native ECMWF ETA coordinate systems. Accuracy improvements are being investigated by quantifying the conservation quantities of dynamical tracers.