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Nataliia Kussul Andrii Kolotii Sergii Skakun Olena Rakoid Leonid Shumilo 《International Journal of Digital Earth》2020,13(2):309-321
ABSTRACTFor evaluating the progresses towards achieving the Sustainable Development Goals (SDGs), a global indicator framework was developed by the UN Inter-Agency and Expert Group on Sustainable Development Goals Indicators. In this paper, we propose an improved methodology and a set of workflows for calculating SDGs indicators. The main improvements consist of using moderate and high spatial resolution satellite data and state-of-the-art deep learning methodology for land cover classification and for assessing land productivity. Within the European Network for Observing our Changing Planet (ERA-PLANET), three SDGs indicators are calculated. In this research, harmonized Landsat and Sentinel-2 data are analyzed and used for land productivity analysis and yield assessment, as well as Landsat 8, Sentinel-2 and Sentinel-1 time series are utilized for crop mapping. We calculate for the whole territory of Ukraine SDG indicators: 15.1.1 – ‘Forest area as proportion of total land area’; 15.3.1 – ‘Proportion of land that is degraded over total land area’; and 2.4.1 – ‘Proportion of agricultural area under productive and sustainable agriculture’. Workflows for calculating these indicators were implemented in a Virtual Laboratory Platform. We conclude that newly available high-resolution remote sensing products can significantly improve our capacity to assess several SDGs indicators through dedicated workflows. 相似文献
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M. Chernyakova A. Neronov F. Aharonian Y. Uchiyama T. Takahashi 《Monthly notices of the Royal Astronomical Society》2009,397(4):2123-2132
PSR B1259−63 is a 48-ms radio pulsar in a highly eccentric 3.4-yr orbit with a Be star SS 2883. Unpulsed γ-ray, X-ray and radio emission components are observed from the binary system. It is likely that the collision of the pulsar wind with the anisotropic wind of the Be star plays a crucial role in the generation of the observed non-thermal emission. The 2007 periastron passage was observed in unprecedented details with Suzaku , Swift , XMM–Newton and Chandra missions. We present here the results of this campaign and compare them with previous observations. With these data we are able, for the first time, to study the details of the spectral evolution of the source over a 2-month period of the passage of the pulsar close to the Be star. New data confirm the pre-periastron spectral hardening, with the photon index reaching a value smaller than 1.5, observed during a local flux minimum. If the observed X-ray emission is due to the inverse Compton (IC) losses of the 10-MeV electrons, then such a hard spectrum can be a result of Coulomb losses, or can be related to the existence of the low-energy cut-off in the electron spectrum. Alternatively, if the X-ray emission is a synchrotron emission of very high-energy electrons, the observed hard spectrum can be explained if the high-energy electrons are cooled by IC emission in Klein–Nishina regime. Unfortunately, the lack of simultaneous data in the TeV energy band prevents us from making a definite conclusion on the nature of the observed spectral hardening and, therefore, on the origin of the X-ray emission. 相似文献
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TeV Gamma Rays From the Galactic Center Direct and Indirect Links to the Massive Black Hole in Sgr A
The recent detection of TeV gamma-radiation from the direction of the Galactic Center within several arc-minutes around Sgr
A* is the first model-independent evidence of existence of high-energy particle accelerator(s) in the central 10 pc region of
our Galaxy. This is an extraordinary site that harbours many remarkable objects with the compact radio source Sgr A* – a hypothetical super-massive black hole (SMBH) – in the dynamical center of the Galaxy. Here we explore the possible direct and indirect links of the reported TeV emission to the SMBH. We show that at least three γ-ray production scenarios that take place close
to the event horizon of the SMBH can explain the reported TeV fluxes. An alternative (or additional) channel of TeV radiation
is related to the run-away protons accelerated in Sgr A*. Quasi-continuous injection of relativistic protons into the surrounding dense gas environment initiates detectable high-energy
gamma-ray emission. The absolute flux and the energy spectrum of this radiation component strongly depend on the history of
particle injection and the character of diffusion of protons during the last 105 yr. For a reasonable combination of a few model parameters, one can explain the detected gamma-ray flux solely by this diffuse
component. 相似文献
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V. V. Shcherbakova V. E. Pavlov V. P. Shcherbakov I. Neronov V. A. Zemtsov 《Izvestiya Physics of the Solid Earth》2006,42(3):233-243
The territory of Karelia (Baltic Shield) is virtually not represented in the global paleomagnetic database for the Lower Riphean time interval (1650—1350 Ma). As regards the paleointensity H an, the huge interval 1–2 Ga in length is represented in the global paleointensity database by only eight determinations concentrated in the interval 1–1.35 Ga. The paper presents results of paleomagnetic studies of volcanic and subvolcanic rocks composing the Early Riphean Salmi Formation, which outcrops in the valley of the lower Tulemaioki River in the northern coast area of Lake Ladoga. Results of the study indicate that, in the Early Riphean time, the East European craton was located in the tropical region of the Southern Hemisphere between 15° S and 40° S. The inferred value of H an is close to the lower boundary of the interval (1.36–11.56) × 1022 A m2, encompassing previously published intensity values of the paleofield 1–1.35 Ga; this supports the hypothesis on the existence of long intervals of a lower field in the period in question [Maquoin et al., 2003]. 相似文献
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Ian McCallum Carsten Montzka Bagher Bayat Stefan Kollet Andrii Kolotii Nataliia Kussul 《International Journal of Digital Earth》2020,13(2):299-308
ABSTRACTThere is a growing recognition of the interdependencies among the supply systems that rely upon food, water and energy. Billions of people lack safe and sufficient access to these systems, coupled with a rapidly growing global demand and increasing resource constraints. Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors, however development of nexus related frameworks has been limited. We describe three open-source models well known in their respective domains (i.e. TerrSysMP, WOFOST and SWAT) where components of each if combined could help decision-makers address the nexus issue. We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework. The outputs of the workflows and the model framework are designed to address the SDGs. 相似文献
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We study time-resolved spectra of the prompt emission of Swift γ-ray bursts (GRB). Our goal is to see if previous BATSE claims of the existence of a large amount of spectra with the low-energy photon indices harder than 2/3 are consistent with Swift data. We perform a systematic search of the episodes of the spectral hardening down to the photon indices ≤2/3 in the prompt emission spectra of Swift GRBs. We show that the data of the Burst Alert Telescope (BAT) instrument on board of Swift are consistent with BATSE data, if one takes into account differences between the two instruments. Much lower statistics of the very hard spectra in Swift GRBs are explained by the smaller field of view and narrower energy band of the BAT telescope. 相似文献
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We discuss the implications of the recent X-ray and TeV γ-ray observations of the PSR B1259–63 system (a young rotation powered pulsar orbiting a Be star) for the theoretical models
of interaction of pulsar and stellar winds. We show that previously considered models have problems to account for the observed
behaviour of the system. We develop a model in which the broad band emission from the binary system is produced in result
of collisions of GeV–TeV energy protons accelerated by the pulsar wind and interacting with the stellar disk. In this model
the high energy γ-rays are produced in the decays of secondary neutral pions, while radio and X-ray emission are synchrotron and inverse Compton
emission produced by low-energy (≤100 MeV) electrons from the decays of secondary charged π
± mesons. This model can explain not only the observed energy spectra, but also the correlations between TeV, X-ray and radio
emission components.
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