bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of different external forcings to the terrestrial carbon cycle variability in extratropical Eurasia in the last millennium
Authors: Savina K D , Eliseev A V 
Published: November 2020

Abstract
The simulations for the last millennium with an Earth system model developed at the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM) are performed. These simulations are forced by changes of the parameters of the Earth orbit, total solar irradiance, volcanic (stratospheric) aerosols optical depth (only since 500 C. E.), atmospheric concentrations of greenhouse gases (CO2, CH4, and N2O), land use, tropospheric sulphate burden, and population density. It is found that the externally forced part of the terrestrial carbon cycle (TCC) interannual variability (IAV) was mostly driven by volcanic activity in the preindustrial part of the last millennium with an increase of importance of anthropogenic forcing during the 20th century. The latter enhanced IAV in the 20th century. For different time intervals and for different kinds of external forcing, coefficient of variation of IAV in different TCC characteristics is smaller (typically, up to few percent) in forested regions and larger in the regions covered by grasses (e.g., in tundra), where it could be as large as several tens of per cents for fire return interval. We show that the externally forced IAV of gross primary production during the 20th century dramatically increased as compared to that during the preindustrial period. In addition, the land use activity increases the relaxation time scale of the vegetation carbon stock by one order of magnitude.
Climate changes in European Russia in 2001-2018
Authors: Shakina N P , Skriptunova E N 
Published: November 2020

Abstract
From the data of observations at 43 aerodromes in European Russia and the neighboring countries for 2001-2018, linear trends are calculated of temperature, humidity, and pressure, and then compared against the temporal changes in pressure field patterns. The latter are estimated on the basis of objective analysis data, using a special software. The linear trends show that the trends of annual-mean and season-mean temperature are positive practically at all the sites, though mean temperature in separate months can exhibit both decrease (in January) and strong increase (in December and summer months). The annual mean dew-point deficit increases in time almost everywhere, while surface pressure increases in the north (larger) part of the area and decreases in its south part. It is shown also, by means of objective classification of pressure field patterns, that the growth of cyclonic situations occurrence frequency dominates in the south part of the area, and the growth of anticyclonic situations occurrence frequency dominates in its main, north part. This result is consistent with the pressure trends distribution over the area.
Validation of global wind wave hindcasts using ERA5, MERRA2, ERA-Interim and CFSRv2 reanalyzes
Authors: Sharmar V , Markina M 
Published: November 2020

Abstract
Four global wind wave hindcasts based on ERA5, MERRA2, ERA-I and CFSR reanalyses and spectral wave model WAVEWATCH III for the period from 1980 to 2017 have been validated against satellite altimetry and NDBC buoys for 1 year. Hindcast based on newly released ECMWF reanalysis ERA5 demonstrated the best agreement with both satellite altimetery (with normalized bias being up to 5%, and RMSE up to 0.5 m) and buoy measurements, including values of upper percentiles. In general, all hindcasts show good correspondence with the observational data and thus can be used in further wind wave climate studies.
On the manifestation of resonant effects in climatic fluctuations
Authors: Sherstyukov B 
Published: November 2020

Abstract
Under the influence of large planets (Jupiter, Saturn, Uranus, Neptune), the Sun moves in outer space along a certain trajectory around the common center of mass of the solar system. Earth follows the sun. It is assumed that part of the barycentric rotation moment is transmitted to the Earth’s rotational moment and zonal currents of the World Ocean. The aim of this work is to obtain estimates of the possible impact on the climate system of additional rotation forces arising on the Earth during the barycentric movement of the Sun around the common center of mass of the Solar system. The climate system is considered as an oscillatory system, which can resonantly perceive external repetitive effects at its own frequencies. The index of the dynamic influence of barycentric rotation on the speed of the axial rotation of the Earth, on the surface temperature of the ocean and on El Nino is proposed. An asynchronous correlation analysis is performed. It is shown that the influence of the dynamic forces of barycentric rotation describe 31% of the total variability of the Earth’s rotation speed with a delay of 5 years, 66% describes the variability of the average annual temperature of the ocean surface in the circumpolar Antarctic current with a delay of 32-37 years. The contribution of the moment of inertia to the total SST variability along other ocean currents is from 25 to 50% with the same delay. It was found that the El Nino phenomenon is a consequence of variations in the circular circulation of oceanic waters in each of the hemispheres of the Pacific Ocean. One of the engines of these variations are perturbations of the ocean circulation in the region of the Antarctic current. The contribution of changes in SST in the Antarctic Current to changes in the NINO3 index is 31%.
Sources and variations of tropospheric ozone in central Siberia: observations and model simulations
Authors: Shtabkin Yu A , Moiseenko K B , Skorokhod A I , Berezina E V , Vasileva A V 
Published: November 2020

Abstract
Impact of climatically significant anthropogenic and natural emissions to seasonal ozone (O3) variations observed at the Zotino Tall Tower Observatory (ZOTTO) in central Siberia in 2007–2012 have quantitatively been estimated using GEOS-Chem chemical transport model. It is shown that the formation of a stable continental pollution plume from sources in Western Europe, European Russia, and southern Siberia plays an important role in regional balance of near-surface ozone and allows to explain up to 15%–17% of the amplitude of O3 annual cycle observed at ZOTTO (∼5–6 ppb).
Reconstruction of the spring-summer precipitation on the Southern Ural
Authors: Vasiliev D Y , Semenov V A , Kucherov S E 
Published: November 2020

AbstractThe article present a reconstruction of the late spring–summer (May–July) precipitation for the Zilair plateau (Southern Urals) based on latewood width chronologies of Scots pine (Pinus sylvestrisL.) for the 1776–2015 period. Wavelet analysis revealed a number of characteristic periodicities in the reconstructed precipitation variability. Cross-wavelet analysis using indices of solar activity (SA), Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO) showed co-variability of the precipitation with SA at about 20-yr, sporadic links to NAO on multi-year to decadal time scale, and a robust link to AMO at multidecadal time scales.
Study of time series of meteorological parameters by wavelet analysis
Authors: Ziuzina N A , Gazaryan V A , Kurbatova J A , Chulichkov A I , Avilov V K , Shapkina N E 
Published: November 2020

Abstract
The paper presents the results of applying the continuous wavelet analysis method to assess the cyclic components of discrete time series. The work is based on an analysis of a long-term series of data on observations of air temperature in the south-west of the Valdai Upland, as well as analysis of data on observations of CO2 concentration in the canopy of the tropical monsoon forest in southern Vietnam. The patterns of wavelet coefficients and integral spectra have been studied for all considered time series. Additionally, the cyclicities contained in the studied series were revealed.
“PREParE SHIPS” for Automated Ship Passages by Modern Decision Support Tools by Exchanging Future Positions
Authors: Hüffmeier J , Sanchez-Heres L , Rylander R , Nord S , Alissa S , Bagge A , Bergljung P , Henkel P , Rydlinger A , Hansen P 
Published: November 2020

Abstract
Misunderstanding the intentions of other vessels is one of the most common causes of ship collisions today. Such misunderstandings are particularly dangerous during navigation in restricted areas, such as fairways, port areas, and inland water ways, and may be exacerbated with the introduction of unmanned vessels. To ensure safe operations, the understanding of the intentions and future positions of manned and unmanned vessels, the PREParE SHIPS project is creating a system capable of determining a ship’s position with high accuracy, predicting its future positions, and communicating the current and future positions. The positioning sub-system combines the signals of Galileo and EGNOS, EGNSS and SBAS respectively, with land based RTK corrections, providing a positioning accuracy of centimetres. Furthermore, by taking advantage of Galileo’s authentication features, the positioning system provides enhanced security measures against spoofing attacks. The prediction sub-system will use a ship dynamic model and machine learning to predict the future positions of the ship and improve said predictions with time, while the communication sub-system will broadcast the prediction through VDES ship2ship and ship2shore. PREParE SHIPS will improve the navigation and handling of ships, through high accuracy positioning and dynamic predictions, as well as reduce the risk of ship collisions, through the communication of present and predicted future positions. PREParE SHIPS is expected to increase safety and efficiency significantly and will be the base of future autonomous operations and standardisations.
A framework for description of autonomous ship systems and operations
Authors: Wennersberg Lars Andreas Lien , Nordahl Håvard , Rødseth Ørnulf Jan , Fjørtoft Kay , Holte Even Ambros 
Published: November 2020

Abstract
The Concept of Operations, or ConOps, has become a central document for the specification, design and approval of autonomous ship systems and operations in the absence of prescriptive rules and regulations. The flexible structure of the ConOps and the fact that it is written in prose text makes it very accessible for all involved stakeholders, but also prone to discrepancies between the descriptions and the actual design. This paper proposes a description framework, for autonomous ship systems and operations, that covers the information items requested through the ConOps. The proposed framework has the potential to facilitate development of a formalized ConOps, which in turn could lead to a standardization of the current approval procedures for autonomous ship systems and operations.
Meaningful Human Control in Autonomous Shipping: An Overview
Authors: van den Broek J (Hans) , Griffioen J R (Jaco) , van der Drift M (Monique) 
Published: November 2020

Abstract
This paper presents an overview of the aspects related to meaningful human control in autonomous shipping. Autonomy is described as a multi-faceted construct including self-sufficiency and self-directedness, which are related to a range of conditions a ship can deal with. This means that autonomy levels will vary in different operational situations. As a consequence, active operator involvement and workload will fluctuate and will sometimes be unpredictable. In case of supervising multiple ships, it is not feasible to maintain a minimal level of situation awareness of all the ships. In order to facilitate operator situation awareness recovery and other human-automation collaboration principles an Intelligent Operator Support System concept is outlined. Whether the large-scale application of Maritime Autonomous Surface Ships will provide equivalent safety and resilience levels will largely depend on the intelligence of the onboard control systems, the design quality of the human-autonomy collaboration system, and the competence and training level of the SC-operators.
Potential benefits of 5G communication for autonomous ships
Authors: Petersen Stig , Orten Pål , Myhre Bård 
Published: November 2020

Abstract
5G, the next generation of mobile networks, aims to deliver wireless connectivity for new applications beyond traditional connectivity and mobile broadband for the smartphone market. For the maritime industry, 5G has the potential to address a wide range of usage scenarios within ship-to-ship, ship-to-shore, and onboard communication. In this paper, we give an introduction to mobile network technologies and systems in general, as well as an overview of technical capabilities and novelties introduced by the forthcoming 5G specifications relevant for maritime operations. Furthermore, perspectives related to applications and opportunities enabled by 5G networks are discussed, along with the potential benefits for unmanned and autonomous ships.
LTE massive MIMO (Pre-5G) test with an updated boat user terminal solution for land-to-boat scenarios in Oslo fjord
Authors: Yang Kun , Zhou Ning , Røste Terje 
Published: November 2020

Abstract
Autonomous shipping is considered to be one of the most important technologies in the maritime industry. Remote control of autonomous shipping is supported by communication solutions featuring long coverage, high throughput and low latency. Since 2018, together with the Norwegian Internet Service Provider (ISP) Telia, we have performed tests with a massive MIMO (Pre-5G) LTE base station, using the 3.7 GHz band, in Horten close to the Oslo fjord. The first Pre-5G tests with user terminal mounted on a 40 feet sailboat performed in 2018, showed great potential for maritime applications in terms of throughputs [1]. The Customer Premise Equipment (CPE) used in 2018 was a LTE Pre-5G terminal from Telia for fixed LAN use, and a modified version of it in 2019. However, since both the base station and the user terminal/CPE are not originally designed and optimized for maritime radio propagation environments, the test results in 2018 unveiled that a CPE designed for land usage experienced limited coverage and instability caused by received unstable signal level. Since 2019, a new user terminal prototype dedicated and optimized for maritime propagation conditions, was designed by Super Radio AS. This new CPE was tested in autumn 2019 under the similar setups as in 2018. The test results of the Reference Signal Receive Power and throughput are analysed and compared the test results in 2018. The comparison proved that the new user terminal solution showed considerable improvement with respect to stability and throughputs in the harsh maritime environments, which means that the new designed solution can be a potential maritime terminal solution for the remote control of autonomous shipping. The prototypes mounted at different places of the sailboat also show different system performances at the same TX-RX distances, which indicates the potential of exploiting the system diversity in the similar propagation environments.
Emergency ship positioning and distribution system for radio disturbance
Authors: Mun Seongmi , Lee Kwaingil 
Published: November 2020

Abstract
Global Navigation Satellite System (GNSS) has been used as a key position, navigation and timing (PNT) input in applications or services provided by ships. However, GNSS is vulnerable to space-vehicle failures, solar disturbances, unintentional radio interference and deliberate jamming. Despite these weaknesses, GNSS has become a key element not only of maritime navigation, but also of critical national infrastructure, often without any backup being provided. In autonomous ships, the use of various integrated systems increases and the dependence on the location data of GNSS increases. Therefore, in the event of a GNSS failure, it is impossible to guarantee the safe operation of the ship and it has various accident possibilities. In this paper, we propose and describe the system newly that can collect PNTs from various equipment to detect anomalies, and measure and distribute PNTs from digital sextants, which are backup systems, when anomalies occur. In the future, we will verify the performance of the implemented system by a test with the full mission bridge simulator provided by the Kongsberg.
Study on the potential gaps and themes identified by IMO Regulatory Scoping Exercise(RSE) for the use of Maritime Autonomous Surface Ships(MASS)
Authors: Jo M.C , Lee A.R , Kim Y.D , Seo J.S 
Published: November 2020

Abstract
Currently, IMO discusses to develop international standard regulations for the use of Maritime Autonomous Surface Ships(MASS), and as a preliminary work to develop them, it carries out RSE work to identify measures that might arise when the existing conventions are applied to MASS. The RSE work is done by the Maritime Safety Committee (MSC), the Legal Committee (LEG), and the Facilitation Committee (FAL) for the conventions under the purview of each committee. In this paper, based on the results of the RSE work performed by each committee, a comprehensive analysis of potential gaps and themes that require further discussion and consideration in the next stage of international standard regulations for the use of MASS is presented.
It’s not all about the COLREGs: a case-based risk study for autonomous coastal ferries
Authors: Rutledal Dag , Relling Tore , Resnes Tron 
Published: November 2020

Abstract
Whilst the maritime world is preparing for autonomous vessels or Maritime Autonomous Surface Ships (MASS), as defined by IMO, we suggest an approach to investigate the risks involved with introducing such ships into service. This case study investigates the risks regarding other surface vessels that the MASS can encounter on their voyage between two berths used by coastal ferries in Norway. The ferries in this case, operate within a fjord declared as testbed for autonomous operations. Albeit the technology is available and declared ready, the area of operation is not. This paper seeks to address some of the remaining obstacles with regards to the risks involved.
Process map for collision avoidance based on information exchange for autonomous navigation of vessel
Authors: Namgung Ho , Jeong Jung Sik , Lee Kwangil , Kim Sun-Young 
Published: November 2020

Abstract
A reliable collision avoidance method is essential when operating an autonomous vessel. For this to become a reality, a number of researches have been conducted in order that the autonomous vessel could take an action for collision avoidance by herself. However, it may lead to dangerous situation without knowing the navigation intention of target-ships. In order to solve the issue, we developed the process map for collision avoidance based on information exchange via the communication relay system as follows: (i) the navigation situation analysis of the autonomous vessel was conducted based on manned ship voyage definition; (ii) the sequence diagram for information exchange was developed based on the autonomous vessel’s navigation context and the communication relay system, and (iii) the process map for collision avoidance based on information exchange was proposed based on the developed sequence diagram and the existing collision avoidance method. It would be expected that the autonomous vessel could avoid collision more safely than taking an action by herself.
A hybrid kinematic controller for resilient obstacle avoidance of autonomous ships
Authors: Marley Mathias , Skjetne Roger , Breivik Morten , Fleischer Caroline 
Published: November 2020

Abstract
Resilience is an important feature of autonomous systems. To be resilient, a control system must be stable, robust, and safe. This paper explores the use of hybrid feedback controllers to ensure robustness towards uncertainties and disturbances in motion control systems for autonomous ships. Motivated by recent developments in control barrier functions (CBFs) for safe maneuvering of autonomous ships, a CBF-based hybrid kinematic controller for obstacle avoidance is proposed. The controller uses course angle as control input, making it suitable for ships with a limited speed envelope. The performance of the controller is illustrated by simulations, using an underactuated ship as a case study.
Standardized navigational data for situational awareness during simultaneous maritime operations
Authors: Hagaseth M. , Berge S. P. 
Published: November 2020

Abstract
The objective of this paper is to describe a protocol for exchange of navigational data between ships operating in close proximity. The protocol supports the exchange of data needed for relative positioning and includes geometry data of the objects involved in the operation in addition to inertial and positional data. The protocol takes into account the variable and limited communication capabilities that may be available for maritime operations. The paper describes one use case where two ships perform a simultaneous operation and another use case where a ship broadcasts its intended route. A S-100 Application Schema covering the required data is presented. Examples of the message exchange and bandwidth requirements are given. The resulting protocol will be useful for autonomous systems and ships that need standardized exchange of data to support situational awareness during their passage. The paper is written as part of the H2H project [1] which is developing an open system architecture to ensure interoperability between different vendors of autonomous systems when it comes to the data exchange related to position and geometry data.
Voyage performance evaluation based on a digital twin model
Authors: Liu M , Zhou Q , Wang X , Yu C , Kang M 
Published: November 2020

Abstract
Using digital twins in voyage performance evaluation is becoming critical for ocean vessels to reduce GHG emissions. A novel GBM approach is proposed in this paper to establish a digital twin model for voyage performance prediction. The weather hindcast data are introduced to enrich noon reports (NR) and automatic identification system (AIS) datasets, which are split into training and validation sets to develop GBM. The NR and AIS datasets collected from a 57000DWT bulk carrier are used to demonstrate the fidelity and capability of the proposed GBM. The voyage performance prediction from the GBM shows better accuracy than those from pure WBM or pure BBMs. An arrival time forecast and a weather routing showcase are also presented to demonstrate the application effects of GBM. The proposed GBM provides a satisfying prediction of ship speed and fuel consumption without mandatory sensor-collected data, thus applicable for a varity of vessels. In those cases where more sensors are available onboard, the proposed approach can incorporate sensor data to improve the model accuracy further.
Research on ontology-based situation understanding and decision-making approach for MASS
Authors: Lan-xuan An , Xin-yu Zhang , Zhi-guo Ding , Cheng-bo Wang 
Published: November 2020

Abstract
Aiming at the problems of miscellaneous navigation safety information and the difficulty of multi-source heterogeneous information fusion, a novel ontology-based collision avoidance decision making method is proposed in this paper. first of all, the structured ontology model of navigation situation is built on the basis of analysing the hierarchy and interactivity of various scene elements in driving scene and constructing the semantic model of entity class and binary attribute of scene elements, implement effective modelling of navigation scenarios. Secondly, the knowledge base of collision avoidance decision and online reasoning system are constructed based on the semantic expression of typical scene elements to realize the efficient utilization of navigation prior knowledge. Finally, the simulation experiment is carried out for the typical ship encounter scenarios in open water. The results show that the ontology method can effectively improve the cognition ability of Maritime Autonomous Surface Ships (MASS), and meet the requirements for real-time, safety and rationality of collision avoidance decision.