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Journal articles on the topic 'National Geophysical Data Center'
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1
Kenny, Maureen R., and Kurt E. Brown. "The national geophysical data center bathymetric program." Marine Geodesy 15, no. 2-3 (January 1992): 165–75. http://dx.doi.org/10.1080/01490419209388052.
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Moore, Carla Jean. "Marine sediment data at the national geophysical data center." Marine Georesources & Geotechnology 12, no. 1 (January 1994): 25–32. http://dx.doi.org/10.1080/10641199409388251.
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Cohen, Lee Mark. "Bathymetric data held at the national geophysical data center." Marine Georesources & Geotechnology 12, no. 1 (January 1994): 53–60. http://dx.doi.org/10.1080/10641199409388253.
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Kihn, E. A., and C. G. Fox. "Geophysical Data Stewardship in the 21st Century at the National Geophysical Data Center (NGDC)." Data Science Journal 12 (2013): WDS193—WDS196. http://dx.doi.org/10.2481/dsj.wds-033.
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Maus, S., T. Sazonova, K. Hemant, J. D. Fairhead, and Dhananjay Ravat. "National Geophysical Data Center candidate for the World Digital Magnetic Anomaly Map." Geochemistry, Geophysics, Geosystems 8, no. 6 (June 2007): n/a. http://dx.doi.org/10.1029/2007gc001643.
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Dunbar, Paula, Heather McCullough, George Mungov, Jesse Varner, and Kelly Stroker. "2011 Tohoku earthquake and tsunami data available from the National Oceanic and Atmospheric Administration/National Geophysical Data Center." Geomatics, Natural Hazards and Risk 2, no. 4 (November 11, 2011): 305–23. http://dx.doi.org/10.1080/19475705.2011.632443.
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Cartwright, John, Jesse Varner, and Susan McLean. "Data Stewardship: How NOAA Delivers Environmental Information for Today and Tomorrow." Marine Technology Society Journal 49, no. 2 (March 1, 2015): 107–11. http://dx.doi.org/10.4031/mtsj.49.2.11.
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AbstractNational Oceanic and Atmospheric Administration's (NOAA's) National Geophysical Data Center (NGDC) ensures the security and widespread availability of scientific marine geophysical data through long-term stewardship. Marine geophysical data extend from the water surface, through the water column, to the seafloor and even the geology beneath. In addition to ensuring the quality, integrity, and accessibility of these data, NGDC develops derived products such as precise representations of Earth's magnetic field and digital elevation models for coastal and marine areas. NOAA and our partners expend significant resources to survey our coasts and oceans. In order to maximize the return on this investment, the data must be easily discoverable and readily accessible by numerous users and applications now and well into the future. To meet these goals, NGDC is drawing on a variety of software technologies and is strictly adhering to international data standards. The result is a geospatial framework built on spatially enabled databases, standard-based Web services, and International Standards Organization (ISO) metadata. NGDC's suite of tools and services delivers over 40 TB of marine geophysical data each year to a wide range of customers. By making the data more accessible to both human and machine clients, NGDC extends the use of, and therefore the value of, these data. The result is environmental information that enables informed decisions.
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Colony, Roger, Vladimir Radionov, and Fred J. Tanis. "Measurements of precipitation and snow pack at Russian North Pole drifting stations." Polar Record 34, no. 188 (January 1998): 3–14. http://dx.doi.org/10.1017/s0032247400014923.
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AbstractThe Russian Arctic and Antarctic Research Institute (AARI) has conducted long-term meteorological studies over the Arctic basin and adjacent Siberian seas. Standard measurements of precipitation and snow geophysical properties were made, consistent with methods recommended by the World Meteorological Organization (WMO). An extensive set of snow and precipitation data has been collected during the last 40 years and has been assembled into a digital database. These data are now kept at the National Snow and Ice Data Center (NSIDC) and World Data Center A for Glaciology. The geophysical properties of snow and sea ice together affect the conductive, turbulent, and radiative energy exchanges between the ocean and atmosphere. The spatial and temporal variations in these exchanges have an impact on virtually all the physical processes operating across this interface. This paper describes some of the basic characteristics of these snow and precipitation data, including seasonal and interannual variability.
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Denig, William F. "The International Council for Science World Data System Stewardship Award 2014 Presented to Dr. Robert Redmon of the National Geophysical Data Center." Space Weather 13, no. 1 (January 2015): 1. http://dx.doi.org/10.1002/2014sw001136.
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Guo, Juan. "A statistical study on solar soft X-ray flare and the sources." Proceedings of the International Astronomical Union 8, S294 (August 2012): 551–52. http://dx.doi.org/10.1017/s1743921313003189.
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AbstractWe surveyed 28 year of Solar X-ray flares and sunspot group records supplied by the National Geophysical Data Center (NGDC) to study the dependence of different class Xray flares on the magnetic structure of sunspot groups statistically. It is found that 82.5% X-class flare, 51.4% M-class flare, 26.3% C-class flare, and 10.1% B-class flare occurred in the sunspot group with βγδ structure. There are 6.6% X-class flares, 17.5% M-class flare, 39.1% C-class flare, and 60.4% B-class flare occurred out of sunspot group.
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Péquegnat, Catherine, Jonathan Schaeffer, Claudio Satriano, Helle Pedersen, Jérôme Touvier, Jean-Marie Saurel, Marie Calvet, et al. "RÉSIF-SI: A Distributed Information System for French Seismological Data." Seismological Research Letters 92, no. 3 (April 7, 2021): 1832–53. http://dx.doi.org/10.1785/0220200392.
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Abstract The Résif project, which started in 2008, aims at gathering under a common research infrastructure the French seismological, Global Navigation Satellite Systems and gravimeter permanent networks, as well as the mobile instrument pools. A central part of Résif is its seismological information system, Système d'Information de Résif (Résif-SI) (started in 2012), which is in charge of collecting, validating, archiving, and distributing seismological data and metadata from seven national centers. Résif-SI follows a distributed architecture, in which the six data collection and validation centers (A-nodes) send validated data and metadata to a national data center (Résif Data Center [Résif-DC]), which is the central point for data archiving and distribution. Résif-SI is based on international standard formats and protocols, and is fully integrated into European and international data exchange systems (European Integrated Data Archive, European Plate Observing System [EPOS], Incorporated Research Institutions for Seismology, International Federation of Digital Seismograph Networks). In this article, we present the organization of Résif-SI, the technical details of its implementation, and the catalog of services provided to the end users. The article is aimed both at seismologists, who want to discover and use Résif data, and at data center operators, who might be interested in the technical choices made in the implementation of Résif-SI. We believe that Résif-SI can be a model for other countries facing the problem of integrating different organizations into a centralized seismological information system.
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Рыбак, Алексей, and Alexey Rybak. "Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles." Solnechno-Zemnaya Fizika 2, no. 2 (June 17, 2016): 22–28. http://dx.doi.org/10.12737/18645.
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This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to Malde classification indices throughout the observation period. The longitude distribution of large sunspot groups made in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.
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Рыбак, Алексей, and Alexey Rybak. "Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles." Solar-Terrestrial Physics 2, no. 2 (August 10, 2016): 28–36. http://dx.doi.org/10.12737/20997.
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This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to classification values after Malde throughout the observation period. The longitude distribution of large sunspot groups plotted in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.
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Derr, John S., and Roger N. Hunter. "The argos seismic data message system." Bulletin of the Seismological Society of America 78, no. 2 (April 1, 1988): 1000–1005. http://dx.doi.org/10.1785/bssa0780021000.
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Abstract A reliable, inexpensive method for sending limited daily seismic data messages from remote observatories to the National Earthquake Information Center has been developed for use with the Argos satellite system. Data messages are compressed on a microcomputer and passed automatically to a simple transmitter. About 4 hr later, the data are available at the National Earthquake Information Center, where they are decompressed and reformatted into standard telegrams for use in quick epicenter determinations. Epicenter data are available daily to the international scientific community.
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Bilitza, D. "Solar-terrestrial models at the National Space Science Data Center." Journal of Atmospheric and Terrestrial Physics 53, no. 11-12 (November 1991): 1207–11. http://dx.doi.org/10.1016/0021-9169(91)90072-f.
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Stickler, A., S. Brönnimann, S. Jourdain, E. Roucaute, A. Sterin, D. Nikolaev, M. A. Valente, et al. "Description of the ERA-CLIM historical upper-air data." Earth System Science Data 6, no. 1 (January 24, 2014): 29–48. http://dx.doi.org/10.5194/essd-6-29-2014.
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Abstract. Historical, i.e. pre-1957, upper-air data are a valuable source of information on the state of the atmosphere, in some parts of the world dating back to the early 20th century. However, to date, reanalyses have only partially made use of these data, and only of observations made after 1948. Even for the period between 1948 (the starting year of the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis) and the International Geophysical Year in 1957 (the starting year of the ERA-40 reanalysis), when the global upper-air coverage reached more or less its current status, many observations have not yet been digitised. The Comprehensive Historical Upper-Air Network (CHUAN) already compiled a large collection of pre-1957 upper-air data. In the framework of the European project ERA-CLIM (European Reanalysis of Global Climate Observations), significant amounts of additional upper-air data have been catalogued (> 1.3 million station days), imaged (> 200 000 images) and digitised (> 700 000 station days) in order to prepare a new input data set for upcoming reanalyses. The records cover large parts of the globe, focussing on, so far, less well covered regions such as the tropics, the polar regions and the oceans, and on very early upper-air data from Europe and the US. The total number of digitised/inventoried records is 61/101 for moving upper-air data, i.e. data from ships, etc., and 735/1783 for fixed upper-air stations. Here, we give a detailed description of the resulting data set including the metadata and the quality checking procedures applied. The data will be included in the next version of CHUAN. The data are available at doi:10.1594/PANGAEA.821222.
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Schertzer, D., and E. Falgarone. "MFGA-IDT2 workshop: Astrophysical and geophysical fluid mechanics: the impact of data on turbulence theories." Nonlinear Processes in Geophysics 3, no. 4 (December 31, 1996): 229–30. http://dx.doi.org/10.5194/npg-3-229-1996.
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Abstract. 1 Facts about the Workshop This workshop was convened on November 13-15 1995 by E. Falgarone and D. Schertzer within the framework of the Groupe de Recherche Mecanique des Fluides Geophysiques et Astrophysiques (GdR MFGA, Research Group of Geophysical and Astrophysical Fluid Mechanics) of Centre National de la Recherche Scientifique (CNRS, (French) National Center for Scientific Research). This Research Group is chaired by A. Babiano and the meeting was held at Ecole Normale Superieure, Paris, by courtesy of its Director E. Guyon. More than sixty attendees participated to this workshop, they came from a large number of institutions and countries from Europe, Canada and USA. There were twenty-five oral presentations as well as a dozen posters. A copy of the corresponding book of abstracts can be requested to the conveners. The theme of this meeting is somewhat related to the series of Nonlinear Variability in Geophysics conferences (NVAG1, Montreal, Aug. 1986; NVAG2, Paris, June 1988; NVAG3, Cargese (Corsica), September, 1993), as well as seven consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions devoted to similar topics. One may note that NVAG3 was a joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first topical conference jointly sponsored by the two organizations. The corresponding proceedings were published in a special NPG issue (Nonlinear Processes in Geophysics 1, 2/3, 1994). In comparison with these previous meetings, MFGA-IDT2 is at the same time specialized to fluid turbulence and its intermittency, and an extension to the fields of astrophysics. Let us add that Nonlinear Processes in Geophysics was readily chosen as the appropriate journal for publication of these proceedings since this journal was founded in order to develop interdisciplinary fundamental research and corresponding innovative nonlinear methodologies in Geophysics. It had an appropriate editorial structure, in particular a large number of editors covering a wide range of methodologies, expertises and schools. At least two of its sections (Scaling and Multifractals, Turbulence and Diffusion) were directly related to the topics of the workshop, in any case contributors were invited to choose their editor freely. 2 Goals of the Workshop The objective of this meeting was to enhance the confrontation between turbulence theories and empirical data from geophysics and astrophysics fluids with very high Reynolds numbers. The importance of these data seems to have often been underestimated for the evaluation of theories of fully developed turbulence, presumably due to the fact that turbulence does not appear as pure as in laboratory experiments. However, they have the great advantage of giving access not only to very high Reynolds numbers (e.g. 1012 for atmospheric data), but also to very large data sets. It was intended to: (i) provide an overview of the diversity of potentially available data, as well as the necessary theoretical and statistical developments for a better use of these data (e.g. treatment of anisotropy, role of processes which induce other nonlinearities such as thermal instability, effect of magnetic field and compressibility ... ), (ii) evaluate the means of discriminating between different theories (e.g. multifractal intermittency models) or to better appreciate the relevance of different notions (e.g. Self-Organized Criticality) or phenomenology (e.g. filaments, structures), (iii) emphasise the different obstacles, such as the ubiquity of catastrophic events, which could be overcome in the various concerned disciplines, thanks to theoretical advances achieved. 3 Outlines of the Workshop During the two days of the workshop, the series of presentations covered many manifestations of turbulence in geophysics, including: oceans, troposphere, stratosphere, very high atmosphere, solar wind, giant planets, interstellar clouds... up to the very large scale of the Universe. The presentations and the round table at the end of the workshop pointed out the following: - the necessity of this type of confrontation which makes intervene numerical simulations, laboratory experiments, phenomenology as well as a very large diversity of geophysical and astrophysical data, - presumably a relative need for new geophysical data, whereas there have been recent astrophysical experiments which yield interesting data and exciting questions; - the need to develop a closer intercomparison between various intermittency models (in particular Log-Poisson /Log Levy models). Two main questions were underlined, in particular during the round table: - the behaviour of the extremes of intermittency, in particular the question of divergence or convergence of the highest statistical moments (equivalently, do the probability distributions have algebraic or more rapid falloffs?); - the extension of scaling ranges; in other words do we need to divide geophysics and astrophysics in many small (nearly) isotropic subranges or is it sufficient to use anisotropic scaling notions over wider ranges? 4 The contributions in this special issue Recalling that some of the most useful insights into the nature of turbulence in fluids have come from observations of geophysical flows, Van Atta gives a review of the impacts of geophysical turbulence data into theories. His paper starts from Taylor's inference of the nearly isotropy of atmospheric turbulence and the corresponding elegant theoretical developments by von Karman of the theory of isotropic turbulence, up to underline the fact that the observed extremely large intermittency in geophysical turbulence also raised new fundamental questions for turbulence theory. The paper discusses the potential contribution to theoretical development from the available or currently being made geophysical turbulence measurements, as well as from some recent laboratory measurements and direct numerical simulations of stably stratified turbulent shear flows. Seuront et al. consider scaling and multiscaling properties of scalar fields (temperature and phytoplankton concentration) advected by oceanic turbulence in both Eulerian and Lagrangian frameworks. Despite the apparent complexity linked to a multifractal background, temperature and fluorescence (i.e. phytoplankton biomass surrogate) fields are expressed over a wide range of scale by only three universal multifractal parameters, H, \\alpha and C_l. On scales smaller than the characteristic scale of the ship, sampling is rather Eulerian. On larger scales, the drifting platform being advected by turbulent motions, sampling may be rather considered as Lagrangian. Observed Eulerian and Lagrangian universal multifractal properties of the physical and biological fields are discussed. Whereas theoretical models provide different scaling laws for fluid and MHD turbulent flows, no attempt has been done up to now to experimentally support evidence for these differences. Carbone et al. use measurements from the solar wind turbulence and from turbulence in ordinary fluid flows, in order to assess these differences. They show that the so-called Extended Self-Similarity (ESS) is evident in the solar wind turbulence up to a certain scale. Furthermore, up to a given order of the velocity structure functions, the scaling laws of MHD and fluids flows axe experimentally indistinguishable. However, differences can be observed for higher orders and the authors speculate on their origin. Dudok de Wit and Krasnosel'skikh present analysis of strong plasma turbulence in the vicinity of the Earth's bow shock with the help of magnetometer data from the AMPTE UKS satellite. They demonstrate that there is a departure from Gaussianity which could be a signature of multifractality. However, they point out that the complexity of plasma turbulence precludes a more quantitative understanding. Finally, the authors emphasise the fact that the duration of records prevents to obtain any reliable estimate of structure functions beyond the fourth order. Sylos Labini and Pietronero discuss the problem of galaxy correlations. They conclude from all the recently available three dimensional catalogues that the distribution of galaxies and clusters is fractal with dimension D ~ 2 up to the present observational limits without any tendency towards homogenization. This result is discussed in contrast to angular data analysis. Furthermore, they point out that the galaxy-cluster mismatch disappears when considering a multifractal distribution of matter. They emphasise that a new picture emerges which changes the standard ideas about the properties of the universe and requires a corresponding change in the related theoretical concepts. Chilla et al. investigate with the help of a laboratory experiment the possible influence of the presence of a large scale structure on the intermittency of small scale structures. They study a flow between coaxial co-rotating disks generating a strong axial vortex over a turbulent background. They show that the cascade process is preserved although strongly modified and they discuss the relevance of parameters developed for the description of intermittency in homogeneous turbulence to evaluate this modification.
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Jiang, Maofei, Ke Xu, and Yalong Liu. "Calibration and Validation of Reprocessed HY-2A Altimeter Wave Height Measurements Using Data from Buoys, Jason-2, Cryosat-2, and SARAL/AltiKa." Journal of Atmospheric and Oceanic Technology 35, no. 6 (June 2018): 1331–52. http://dx.doi.org/10.1175/jtech-d-17-0151.1.
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AbstractThe Haiyang-2A (HY-2A) satellite is China’s first ocean dynamic environment satellite, and the radar altimeter is one of its main payloads. In this study the HY-2A altimeter sensor interim geophysical dataset records (SIGDR) data are reprocessed to obtain better significant wave height (Hs) measurements over a period of more than four years (from 1 October 2011 to 15 March 2016). The reprocessed HY-2A Hs measurements are calibrated and validated using National Data Buoy Center (NDBC) buoys and several operating altimeters: Joint Altimetry Satellite Oceanography Network-2 (Jason-2), CryoSat-2, and Satellite with Argos Data Collection System and Ka-Band Altimeter (SARAL/ALtiKa) The final results of buoys and cross-altimeter comparisons show that the accuracy of the reprocessed HY-2A Hs measurements is significantly improved with respect to the Hs measurements in the operational HY-2A interim geophysical data record (IGDR) publicly distributed by the National Satellite Ocean Application Service (NSOAS), State Oceanic Administration (SOA) of China. Compared with the NDBC Hs measurements, the reprocessed HY-2A Hs measurements show a root-mean-square error (RMSE) of 0.215 m with a positive bias of 0.117 m. After calibrating with the two-branched corrections, the RMSE for the reprocessed HY-2A Hs measurements is reduced to 0.173 m, which is lower than those for the calibrated HY-2A IGDR, Jason-2, Cryosat-2, and SARAL measurements with an RMSE of 0.278, 0.233, 0.239, and 0.184 m, respectively. Long-term validation of the altimeter Hs measurements shows that the reprocessed HY-2A Hs measurements after calibration are stable with respect to the buoys and three other altimeters over the entire period. The reprocessed HY-2A Hs measurements are expected to improve the practical applicability of HY-2A Hs measurements significantly.
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Gao, Guoming, Guofa Kang, Guangquan Li, and Chunhua Bai. "Crustal magnetic anomaly and Curie surface beneath Tarim Basin, China, and its adjacent area." Canadian Journal of Earth Sciences 52, no. 6 (June 2015): 357–67. http://dx.doi.org/10.1139/cjes-2014-0204.
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Based on the geomagnetic field model NGDC-720-V3 (National Geophysical Data Center), the distribution of crustal magnetic anomalies and the Curie surface beneath Tarim Basin, China, and its adjacent area were investigated. The results show that the spatial distribution of the magnetic anomalies in Tarim Basin coincides with the regional tectonic structure, i.e., a basin sandwiched between mountain ranges. Shallow parts of the Curie surface are located in uplifted zones of the basin and correspond well to high values of heat flow. In contrast, deep parts of the Curie surface, having low values of heat flow, are distributed along the depression zones of the basin. The Curie point depth is consistent with the measured heat flow value, with a correlation coefficient of 0.65.
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Foken, Thomas, and Steven Oncley. "Workshop on Instrumental and Methodical Problems of Land Surface Flux Measurements." Bulletin of the American Meteorological Society 76, no. 7 (July 1, 1995): 1191–224. http://dx.doi.org/10.1175/1520-0477-76.7.1191.
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This report summarizes presentations and discussions that occurred at a workshop held in conjunction with the XIXth General Assembly of the European Geophysical Society (EGS) from 22 to 24 April 1994. The purpose of this workshop was to define the state of the art of micrometeorological flux measurements, to identify problem areas, and to define any additional data that must be taken to solve these problems. This workshop was organized in response to a proposal made at the 1993 EGS conference by T. Foken, T. Delany (National Center for Atmospheric Research), S. Oncley, and L. Tsvang (Institute of Atmospheric Physics, Russia) for a new experiment to investigate the problem of the “unclosed” energy balance. Sixty-one scientists from 14 countries participated in the workshop.
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Lopez, Joaquín Marcelo, Rodolfo Gerardo Ezquer, Marcelo Roque Albornoz, Carlos Exequiel Garay, and Luis Alberto Scidá. "Comparacion entre Valores de Vtec Predichos por el Modelo Nequick2 y los Obtenidos a Partir de Gps sobre Boulder durante muy baja actividad Solar." Revista Tecnología y Ciencia, no. 34 (February 8, 2019): 80–92. http://dx.doi.org/10.33414/rtyc.34.80-92.2019.
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Una especificación confiable del estado de la ionósfera dada por modelos empíricos es importante para mitigar los efectos que esta zona atmosférica produce sobre las operaciones de los sistemas de posicionamiento y navegación basadas en satélites.Este estudio evalúa la capacidad del modelo NeQuick2 para predecir el contenido electrónico vertical total (VTEC), hasta la altura de los satélites GPS, sobre Boulder (40,00°N, 254,75°E), durante una época de muy baja actividad solar. Para ello se comparan las predicciones del modelo con valores de VTEC obtenidos a partir de señales de satélites GPS, publicados por el National Geophysical Data Center (NGDC) de EEUU.Teniendo en cuenta las incertezas de los valores de GPS VTEC publicados por el NGDC, los resultados muestran que el modelo estudiado, en general, se comporta como un buen predictor del contenido electrónico total en las condiciones solares consideradas.
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J K S, YADAV. "AN INTEGRATED APPROACH IN DESIGN, INSTALLATION AND COMMISSIONING OF MIRROR RTH AND GLOBAL INFORMATION SYSTEM CENTER (GISC) AT, PUNE." MAUSAM 71, no. 1 (August 4, 2021): 149–58. http://dx.doi.org/10.54302/mausam.v71i1.14.
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WMO Information System (WIS)/Global Information System Center (GISC) and Mirror of Regional Telecommunication Hub (RTH) is basically a metadata catalogue web service and allows Data communication, synchronization of metadata with other Data Collection or Production Center (DCPC), GISCs or National Centers (NC’s) based on protocol OAI-PMH. Such catalogue is quite useful for rapidly integrating real-time and non- real- time data sets for better interpretation of weather systems by the forecaster (Singh et al., 2017).
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Aroori, Mahender, G. Yellaiah, and K. Chenna Reddy. "Variation of Quiet Sun Radiation during Solar Cycles 23 and 24." Proceedings of the International Astronomical Union 13, S335 (July 2017): 11–13. http://dx.doi.org/10.1017/s1743921317007992.
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AbstractRadio observations play a very important role in understanding the structure of the solar atmosphere. In this paper the quiet sun component of the solar radio emission has been investigated using data obtained from the Solar Indices Bulletin, National Geophysical Data Centre. By statistical method, the quiet sun component is estimated for 84 successive basic periods containing three solar rotations each using data obtained at different frequencies. From the quiet sun component we estimate the brightness temperature in each observing frequency.
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Papoutsis, Ioannis, Charalampos Kontoes, Stavroula Alatza, Alexis Apostolakis, and Constantinos Loupasakis. "InSAR Greece with Parallelized Persistent Scatterer Interferometry: A National Ground Motion Service for Big Copernicus Sentinel-1 Data." Remote Sensing 12, no. 19 (October 1, 2020): 3207. http://dx.doi.org/10.3390/rs12193207.
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Advances in synthetic aperture radar (SAR) interferometry have enabled the seamless monitoring of the Earth’s crust deformation. The dense archive of the Sentinel-1 Copernicus mission provides unprecedented spatial and temporal coverage; however, time-series analysis of such big data volumes requires high computational efficiency. We present a parallelized-PSI (P-PSI), a novel, parallelized, and end-to-end processing chain for the fully automated assessment of line-of-sight ground velocities through persistent scatterer interferometry (PSI), tailored to scale to the vast multitemporal archive of Sentinel-1 data. P-PSI is designed to transparently access different and complementary Sentinel-1 repositories, and download the appropriate datasets for PSI. To make it efficient for large-scale applications, we re-engineered and parallelized interferogram creation and multitemporal interferometric processing, and introduced distributed implementations to best use computing cores and provide resourceful storage management. We propose a new algorithm to further enhance the processing efficiency, which establishes a non-uniform patch grid considering land use, based on the expected number of persistent scatterers. P-PSI achieves an overall speed-up by a factor of five for a full Sentinel-1 frame for processing in a 20-core server. The processing chain is tested on a large-scale project to calculate and monitor deformation patterns over the entire extent of the Greek territory—our own Interferometric SAR (InSAR) Greece project. Time-series InSAR analysis was performed on volumes of about 12 TB input data corresponding to more than 760 Single Look Complex Sentinel-1A and B images mostly covering mainland Greece in the period of 2015–2019. InSAR Greece provides detailed ground motion information on more than 12 million distinct locations, providing completely new insights into the impact of geophysical and anthropogenic activities at this geographic scale. This new information is critical to enhancing our understanding of the underlying mechanisms, providing valuable input into risk assessment models. We showcase this through the identification of various characteristic geohazard locations in Greece and discuss their criticality. The selected geohazard locations, among a thousand, cover a wide range of catastrophic events including landslides, land subsidence, and structural failures of various scales, ranging from a few hundredths of square meters up to the basin scale. The study enriches the large catalog of geophysical related phenomena maintained by the GeObservatory portal of the Center of Earth Observation Research and Satellite Remote Sensing BEYOND of the National Observatory of Athens for the opening of new knowledge to the wider scientific community.
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Wu, Chun-Chieh, Kun-Hsuan Chou, Po-Hsiung Lin, Sim D. Aberson, Melinda S. Peng, and Tetsuo Nakazawa. "The Impact of Dropwindsonde Data on Typhoon Track Forecasts in DOTSTAR." Weather and Forecasting 22, no. 6 (December 1, 2007): 1157–76. http://dx.doi.org/10.1175/2007waf2006062.1.
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Abstract Starting from 2003, a new typhoon surveillance program, Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region (DOTSTAR), was launched. During 2004, 10 missions for eight typhoons were conducted successfully with 155 dropwindsondes deployed. In this study, the impact of these dropwindsonde data on tropical cyclone track forecasts has been evaluated with five models (four operational and one research models). All models, except the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane model, show the positive impact that the dropwindsonde data have on tropical cyclone track forecasts. During the first 72 h, the mean track error reductions in the National Centers for Environmental Prediction’s (NCEP) Global Forecast System (GFS), the Navy Operational Global Atmospheric Prediction System (NOGAPS) of the Fleet Numerical Meteorology and Oceanography Center (FNMOC), and the Japanese Meteorological Agency (JMA) Global Spectral Model (GSM) are 14%, 14%, and 19%, respectively. The track error reduction in the Weather Research and Forecasting (WRF) model, in which the initial conditions are directly interpolated from the operational GFS forecast, is 16%. However, the mean track improvement in the GFDL model is a statistically insignificant 3%. The 72-h-average track error reduction from the ensemble mean of the above three global models is 22%, which is consistent with the track forecast improvement in Atlantic tropical cyclones from surveillance missions. In all, despite the fact that the impact of the dropwindsonde data is not statistically significant due to the limited number of DOTSTAR cases in 2004, the overall added value of the dropwindsonde data in improving typhoon track forecasts over the western North Pacific is encouraging. Further progress in the targeted observations of the dropwindsonde surveillances and satellite data, and in the modeling and data assimilation system, is expected to lead to even greater improvement in tropical cyclone track forecasts.
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Sharma, D. K., J. Rai, M. Israil, P. Subrahmanyam, P. Chopra, and S. C. Garg. "Enhancement in electron and ion temperatures due to solar flares as measured by SROSS-C2 satellite." Annales Geophysicae 22, no. 6 (June 14, 2004): 2047–52. http://dx.doi.org/10.5194/angeo-22-2047-2004.
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Abstract. The observations on the ionospheric electron and ion temperatures (Te and Ti) measured by the RPA payload aboard the SROSS-C2 satellite have been used to study the effect of solar flares on ionospheric heating. The data on solar flare has been obtained from the National Geophysical Data Center (NGDC) Boulder, Colorado (USA). It has been found that the electron and ion temperatures have a consistent enhancement during the solar flares on the dayside Earth's ionosphere. The estimated enhancement for the average electron temperature is from 1.3 to 1.9 times whereas for ion temperature it is from 1.2 to 1.4 times to the normal days average temperature. The enhancement of ionospheric temperatures due to solar flares is correlated with the diurnal variation of normal days' ionospheric temperatures. The solar flare does not have any significant effect on the nightside ionosphere. A comparison with the temperature obtained from the IRI-95 model also shows a similar enhancement.
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Golynsky, D. A., and A. V. Golynsky. "Unique geological structures of the Law Dome and Vanderford and Totten glaciers region (Wilkes Land) distinguished by geophysical data." Arctic and Antarctic Research 65, no. 2 (July 9, 2019): 212–31. http://dx.doi.org/10.30758/0555-2648-2019-65-2-212-231.
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Wilkes Land is a key region for Gondwana reconstruction, however it remains one of the largest regions on Earth with poorest knowledge of geology. This study comprehensively reviews the ICECAP/ IceBridge geophysical data for the Law Dome region including Vanderford and Totten adjacent glaciers over Wilkes Land and their role in obtaining new insight on the East Antarctic geology hidden under the ice cover. We analyzed more than 100,000 line kilometers of new magnetic, gravity and subglacial bedrock topography data that are available through the National Snow and Ice Data Center (USA). The newly acquired data supports our previous idea of the continuous rift structure existence at the southern boundary of Law Dome that runs between Vanderford and Totten Glaciers. The rift length exceeds 400 km and width varies from 50 to 100 km. In accordance with results of depth to Moho estimations and density modelling, for axial part of the rift it is characteristic an essential thinning of the Earth crust thickness, it is raised up to 24–26 km and continue to be elevated along entire length of this structure. The thickness of sedimentary rocks within the rift exceeds 3 km, their high density probably evidence that they were formed during Late Paleozoic – Early Mesozoic. The results of our investigations support tectonic nature of this structure as continuous rift developed since the Mesozoic extension phase (~160 Ma) of the Wilkes Land continental margin. Second distinctive structure is the strong reversely magnetized Law Dome magnetic anomaly with an area of about 9,500 km2. This anomaly would map out one of the largest mafic/ultramafic intrusions of the Earth, similar in extent to Norway’s Bjerkreim-Sokndal layered intrusion, the Coompana Block gabbro in Australia, or even the granitic-gneiss complex in the Adirondack Mountains of North America.
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Umar, Roslan, Wardatul Jannah Awang, Siti Nadhirah Berzanji, Nur Farhana Abd Majed, Mohd Khairul Amri Kamarudin, and Musa Garba Abdullahi. "Spatial Model of Sky Brightness Magnitude in KUSZA Observatory, UniSZA." International Journal of Engineering & Technology 7, no. 2.15 (April 6, 2018): 13. http://dx.doi.org/10.14419/ijet.v7i2.15.11189.
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Light pollution is the by-product of anthropogenic activities result from the increases in advanced economic and urbanization. Light pollution limits the ability to view the night sky by astronomers, on biodiversity, and ecosystems. This technology nowadays has led us to increase the convenient method to observe the brightness of night sky to determine how much the night sky polluted by artificial light. The study used SQM device and monitored the sky brightness of the KUSZA Observatory in Merang, Setiu, Terengganu, Malaysia. The results obtained were used to compare with the results obtained by simulation data generated from Earth Observation Group (EOG) of National Oceanic and Atmospheric Administration (NOAA), National Geophysical Data Center. It is the first world atlas of the artificial night sky brightness using GIS Interpolation tools. The result showed that the Kusza Observatory Merang is still appropriate to be the place of observation of celestial objects to either optical or radio astronomers. Hence, we recommended that through the data obtained from Defense Meteorological Satellite Program (DMSP) satellites, the value of sky brightness from all over the world can be used to make further analysis and to increase the precision of data recorded through observations. This study provides a clear view mapping of the accessing the sky condition using Geographic Information System (GIS) analysis in the study area.
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Yang, Junxin, Bing Han, Lihua Zhong, Xinzhe Yuan, Xiaochen Wang, Yuxin Hu, and Chibiao Ding. "First Assessment of GF3-02 SAR Ocean Wind Retrieval." Remote Sensing 14, no. 8 (April 14, 2022): 1880. http://dx.doi.org/10.3390/rs14081880.
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On 23 November 2021, the Gaofen-3-02 (GF3-02) satellite was successfully launched in the Jiuquan Satellite Launch Center of China. The primary payload is C-band Synthetic Aperture Radar (SAR), with a maximum resolution of 1 m, and includes 12 imaging modes such as Spotlight, Strip, and TOPSAR, which will play an essential role in marine environment monitoring. As an important marine environmental parameter, the wind speed accuracy retrieved by GF3-02 SAR directly reflects its performance and effectiveness as an operational product. Therefore, based on the wind data of buoys of the National Data Buoy Center (NDBC), ECMWF reanalysis V5 (ERA5), and HY-2B Scatterometer (SCA), a preliminary accuracy assessment of the wind speed retrieved by GF3-02 SAR is carried out in this paper. The wind speed retrieval accuracy of GF3-02 SAR in the co-polarization (HH+VV) data under different Geophysical Model Functions (GMFs) is discussed by using 478 level-1A Single Look Complex (SLC) ocean products acquired in Quad-Polarization Strip I (QPSI) and produced by the National Satellite Ocean Application Service (NSOAS) from January to March 2022. The results show that the optimal root mean square errors (RMSE) are 1.40 m/s, 1.18 m/s, and 1.24 m/s for the VV polarization and 1.39 m/s, 1.19 m/s, and 1.52 m/s for the HH polarization compared to the NDBC wind speed, the ERA5 wind speed, and the HY-2B SCA wind speed, respectively. The preliminary results show that GF3-02 SAR has good wind speed retrieval ability and can meet the needs of operational products.
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Meng, Lei, Yijun He, Jinnian Chen, and Yumei Wu. "Neural Network Retrieval of Ocean Surface Parameters from SSM/I Data." Monthly Weather Review 135, no. 2 (February 1, 2007): 586–97. http://dx.doi.org/10.1175/mwr3292.1.
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Abstract A new algorithm based on the multiparameter neural network is proposed to retrieve wind speed (WS), sea surface temperature (SST), sea surface air temperature, and relative humidity (RH) simultaneously over the global oceans from Special Sensor Microwave Imager (SSM/I) observations. The retrieved geophysical parameters are used to estimate the surface latent heat flux and sensible heat flux using a bulk method over the global oceans. The neural network is trained and validated with the matchups of SSM/I overpasses and National Data Buoy Center buoys under both clear and cloudy weather conditions. In addition, the data acquired by the 85.5-GHz channels of SSM/I are used as the input variables of the neural network to improve its performance. The root-mean-square (rms) errors between the estimated WS, SST, sea surface air temperature, and RH from SSM/I observations and the buoy measurements are 1.48 m s−1, 1.54°C, 1.47°C, and 7.85, respectively. The rms errors between the estimated latent and sensible heat fluxes from SSM/I observations and the Xisha Island (in the South China Sea) measurements are 3.21 and 30.54 W m−2, whereas those between the SSM/I estimates and the buoy data are 4.9 and 37.85 W m−2, respectively. Both of these errors (those for WS, SST, and sea surface air temperature, in particular) are smaller than those by previous retrieval algorithms of SSM/I observations over the global oceans. Unlike previous methods, the present algorithm is capable of producing near-real-time estimates of surface latent and sensible heat fluxes for the global oceans from SSM/I data.
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Evangelidis, Christos P., Nikolaos Triantafyllis, Michalis Samios, Kostas Boukouras, Kyriakos Kontakos, Olga-Joan Ktenidou, Ioannis Fountoulakis, et al. "Seismic Waveform Data from Greece and Cyprus: Integration, Archival, and Open Access." Seismological Research Letters 92, no. 3 (March 10, 2021): 1672–84. http://dx.doi.org/10.1785/0220200408.
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Abstract The National Observatory of Athens data center for the European Integrated Data Archive (EIDA@NOA) is the national and regional node that supports International Federation of Digital Seismograph Networks and related webservices for seismic waveform data coming from the southeastern Mediterranean and the Balkans. At present, it serves data from eight permanent broadband and strong-motion networks from Greece and Cyprus, individual stations from the Balkans, temporary networks and aftershock deployments, and earthquake engineering experimental facilities. EIDA@NOA provides open and unlimited access from redundant node end points, intended mainly for research purposes (see Data and Resources). Analysis and quality control of the complete seismic data archive is performed initially by calculating waveform metrics and data availability. Seismic ambient noise metrics are estimated based on power spectral densities, and an assessment of each station’s statistical mode is achieved within each network and across networks. Moreover, the minimum ambient noise level expected for strong-motion installations is defined. Sensor orientation is estimated using surface-wave polarization methods to detect stations with misalignment on particular epochs. A single data center that hosts the complete seismic data archives with their respective metadata from networks covering similar geographical areas allows coordination between network operators and facilitates the adhesion to widely used best practices regarding station installation, data curation, and metadata definition. The overall achievement is harmonization among all contributing networks and a wider usage of all data archives, ultimately strengthening seismological research efforts in the region.
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Kirtman, Ben P., and Dughong Min. "Multimodel Ensemble ENSO Prediction with CCSM and CFS." Monthly Weather Review 137, no. 9 (September 1, 2009): 2908–30. http://dx.doi.org/10.1175/2009mwr2672.1.
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Abstract Results are described from a large sample of coupled ocean–atmosphere retrospective forecasts during 1982–98. The prediction system is based on the National Center for Atmospheric Research (NCAR) Community Climate System Model, version 3 (CCSM3.0), and a state-of-the-art ocean data assimilation system made available by the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory (GFDL). The retrospective forecasts are initialized in January, April, July, and November of each year, and ensembles of 6 forecasts are run for each initial month, yielding a total of 408 1-yr predictions. In generating the ensemble members, perturbations are added to the atmospheric initial state only. The skill of the prediction system is analyzed from both a deterministic and a probabilistic perspective, it is then compared to the operational NOAA Climate Forecast System (CFS), and the forecasts are combined with CFS to produce a multimodel prediction system. While the skill scores for each model are highly dependent on lead time and initialization month, the overall level of skill of the individual models is quite comparable. The multimodel combination (i.e., the unweighted average of the forecast), while not always the most skillful, is generally as skillful as the best model, using either deterministic or probabilistic skill metrics.
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Newman, Paul A., Mark R. Schoeberl, and R. Alan Plumb. "Horizontal mixing coefficients for two-dimensional chemical models calculated from National Meteorological Center data." Journal of Geophysical Research: Atmospheres 91, no. D7 (June 20, 1986): 7919–24. http://dx.doi.org/10.1029/jd091id07p07919.
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Carrilho, Fernando, Susana Custódio, Mourad Bezzeghoud, Carlos Sousa Oliveira, Célia Marreiros, Dina Vales, Paulo Alves, et al. "The Portuguese National Seismic Network—Products and Services." Seismological Research Letters 92, no. 3 (February 17, 2021): 1541–70. http://dx.doi.org/10.1785/0220200407.
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Abstract Portugal, located in the southwest region of the Eurasian plate, has been affected by several destructive earthquakes throughout its history, the most well-known being the 1755 Great Lisbon earthquake. The seismicity of the territory, both in the mainland and in the Azores and Madeira islands, has prompted the continuous development of seismic monitoring, from the first known macroseismic inquiry, following the 1755 Great Lisbon earthquake, to the current state-of-the-art seismic network. Once scattered in separate efforts, at present, most seismic stations in Portugal relay its data to a common data center, at Instituto Português do Mar e da Atmosfera, where data are automatically processed for the downstream generation of both manually revised and automatically generated products and services. In this article, we summarize the evolution of the permanent seismic network, its current status, the products and services that are publicly available, a recent effort of rapid deployment of a dense network following a mainshock, and state-of-the-art ocean-bottom seismometer developments.
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Widodo, Amien, Firman Syaifuddin, Wien Lestari, and Dwa Desa Warnana. "Earthquake potential source identification using magnetotelluric data of Kendeng thrust Surabaya area." E3S Web of Conferences 156 (2020): 01002. http://dx.doi.org/10.1051/e3sconf/202015601002.
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The existence of the kendeng fault passing Surabaya is still the subject of study by the researchers after being declared active by the National Earthquake Centre. The Surabaya was passed by two segments of the Kendeng fault, the Surabaya segment and the Waru segment, the two segments had an earthquake potential of 6.5 M. In the context of disaster mitigation and earthquake analysis, more detailed information is needed relating to the geometry and position of the earthquake source with certainty, so that the identification of earthquake sources is needed in more detail. The magnetotelluric method is one of the geophysical methods that is able to properly identify anomalous objects in tens of kilometers depth. Kendeng fault as a potential earthquake source, one of its segments across Surabaya can be identified using the magnetotelluric method. Megnetolelluric measurements were carried out as many as 15 points in the Surabaya region in order to identify the geometry of the kendeng fault. From the 3D resistivity model, the inversion of magnetotelluric data can be identified well with the Kendeng fault that crosses the city of Surabaya, both the Waru segment and the Surabaya segment at a depth of less than 8 km
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Welling, D. T. "The long-term effects of space weather on satellite operations." Annales Geophysicae 28, no. 6 (June 24, 2010): 1361–67. http://dx.doi.org/10.5194/angeo-28-1361-2010.
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Abstract. Integrated lifetime radiation damage may cause spacecraft to become more susceptible to operational anomalies by changing material characteristics of electronic components. This study demonstrates and quantifies the impact of these effects by examining the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC) satellite anomaly database. Energetic particle data from the Geostationary Operational Environmental Satellites (GOES) is used to construct the total lifetime particle exposure a satellite has received at the epoch of an anomaly. These values are compared to the satellite's chronological age and the average exposure per year (calculated over two solar cycles.) The results show that many anomalies occur on satellites that have received a total lifetime high-energy particle exposure that is disproportionate to their age. In particular, 10.8% of all events occurred on satellites that received over two times more 20 to 40 MeV proton lifetime particle exposure than predicted using an average annual mean. This number inflates to 35.2% for 40 to 80 MeV protons and 33.7% for ≥2 MeV electrons. Overall, 73.5% of all anomalies occurred on a spacecraft that had experienced greater than two times the expected particle exposure for one of the eight particle populations used in this study. Simplistically, this means that the long term radiation background exposure matters, and that if the background radiation is elevated during the satellite's lifetime, the satellite is likely to experience more anomalies than satellites that have not been exposed to the elevated environment.
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Yu, Jinhai, Bang An, Huan Xu, Zhongmiao Sun, Yuwei Tian, and Qiuyu Wang. "An Iterative Algorithm for Predicting Seafloor Topography from Gravity Anomalies." Remote Sensing 15, no. 4 (February 15, 2023): 1069. http://dx.doi.org/10.3390/rs15041069.
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As high-resolution global coverage cannot easily be achieved by direct bathymetry, the use of gravity data is an alternative method to predict seafloor topography. Currently, the commonly used algorithms for predicting seafloor topography are mainly based on the approximate linear relationship between topography and gravity anomaly. In actual application, it is also necessary to process the corresponding data according to some empirical methods, which can cause uncertainty in predicting topography. In this paper, we established analytical observation equations between the gravity anomaly and topography, and obtained the corresponding iterative solving method based on the least square method after linearizing the equations. Furthermore, the regularization method and piecewise bilinear interpolation function are introduced into the observation equations to effectively suppress the high-frequency effect of the boundary sea region and the low-frequency effect of the far sea region. Finally, the seafloor topography beneath a sea region (117.25°–118.25°E, 13.85°–14.85°N) in the South China Sea is predicted as an actual application, where gravity anomaly data of the study area with a resolution of 1′ × 1′ are from the DTU17 model. Comparing the prediction results with the data of ship soundings from the National Geophysical Data Center (NGDC), the root-mean-square (RMS) error and relative error can be up to 127.4 m and approximately 3.4%, respectively.
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Carlos, Reyes, Ayesta Gárate, and Navarro Reyes. "Solar flares and variation of local geomagnetic field: Measurements by the Huancayo Observatory over 2001-2010." Serbian Astronomical Journal, no. 194 (2017): 87–99. http://dx.doi.org/10.2298/saj160424002c.
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We study the local variation of the geomagnetic field measured by the Huancayo Geomagnetic Observatory, Peru, during 2001-2010. Initially, we sought to relate the SFI values, stored daily in the NOAA's National Geophysical Data Center, with the corresponding geomagnetic index; however, no relation was observed. Nonetheless, subsequently, a comparison between the monthly geomagnetic-activity index and the monthly SFI average allowed observing a temporal correlation between these average indices. This correlation shows that the effect of the solar flares does not simultaneously appear on the corresponding magnetic indices. To investigate this, we selected the most intense X-class flares; then, we checked the magnetic field disturbances observed in the Huancayo Geomagnetic Observatory magnetograms. We found some disturbances of the local geomagnetic field in the second and third day after the corresponding solar flare; however, the disturbance strength of the local geomagnetic field is not correlated with the X-class of the solar flare. Finally, there are some disturbances of the local geomagnetic field that are simultaneous with the X-class solar flares and they show a correlation with the total flux of the solar flare.
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Sun, Tianqi, Guosheng Zhang, William Perrie, Biao Zhang, Changlong Guan, Shahid Khurshid, Kerri Warner, and Jian Sun. "Ocean Wind Retrieval Models for RADARSAT Constellation Mission Compact Polarimetry SAR." Remote Sensing 10, no. 12 (December 2, 2018): 1938. http://dx.doi.org/10.3390/rs10121938.
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We propose two new ocean wind retrieval models for right circular-vertical (RV) and right circular-horizontal (RH) polarizations respectively from the compact-polarimetry (CP) mode of the RADARSAT Constellation Mission (RCM), which is scheduled to be launched in 2019. For compact RV-polarization (right circular transmit and vertical receive), we build the wind retrieval model (denoted CoVe-Pol model) by employing the geophysical model function (GMF) framework and a sensitivity analysis. For compact RH polarization (right circular transmit and horizontal receive), we build the wind retrieval model (denoted the CoHo-Pol model) by using a quadratic function to describe the relationship between wind speed and RH-polarized normalized radar cross-sections (NRCSs) along with radar incidence angles. The parameters of the two retrieval models are derived from a database including wind vectors measured by in situ National Data Buoy Center (NDBC) buoys and simulated RV- and RH-polarized NRCSs and incidence angles. The RV- and RH-polarized NRCSs are generated by a RCM simulator using C-band RADARSAT-2 quad-polarized synthetic aperture radar (SAR) images. Our results show that the two new RCM CP models, CoVe-Pol and CoHo-POL, can provide efficient methodologies for wind retrieval.
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Yunus, Ali P., Jie Dou, Xuan Song, and Ram Avtar. "Improved Bathymetric Mapping of Coastal and Lake Environments Using Sentinel-2 and Landsat-8 Images." Sensors 19, no. 12 (June 21, 2019): 2788. http://dx.doi.org/10.3390/s19122788.
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The bathymetry of nearshore coastal environments and lakes is constantly reworking because of the change in the patterns of energy dispersal and related sediment transport pathways. Therefore, updated and accurate bathymetric models are a crucial component in providing necessary information for scientific, managerial, and geographical studies. Recent advances in satellite technology revolutionized the acquisition of bathymetric profiles, offering new vistas in mapping. This contribution analyzed the suitability of Sentinel-2 and Landsat-8 images for bathymetric mapping of coastal and lake environments. The bathymetric algorithm was developed using an empirical approach and a random forest (RF) model based on the available high-resolution LiDAR bathymetric data for Mobile Bay, Tampa Bay, and Lake Huron regions obtained from the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC). Our results demonstrate that the satellite-derived bathymetry is efficient for retrieving depths up to 10 m for coastal regions and up to 30 m for the lake environment. While using the empirical approach, the root-mean-square error (RMSE) varied between 1.99 m and 4.74 m for the three regions. The RF model, on the other hand, provided an improved bathymetric model with RMSE between 1.13 m and 1.95 m. The comparative assessment suggests that Sentinel-2 has a slight edge over Landsat-8 images while employing the empirical approach. On the other hand, the RF model shows that Landsat-8 retrieves a better bathymetric model than Sentinel-2. Our work demonstrated that the freely available Sentinel-2 and Landsat-8 imageries proved to be reliable data for acquiring updated bathymetric information for large areas in a short period.
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Falkovich, Aleksandr, Isaac Ginis, and Stephen Lord. "Ocean Data Assimilation and Initialization Procedure for the Coupled GFDL/URI Hurricane Prediction System." Journal of Atmospheric and Oceanic Technology 22, no. 12 (December 1, 2005): 1918–32. http://dx.doi.org/10.1175/jtech1810.1.
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Abstract A new ocean data assimilation and initialization procedure is presented. It was developed to obtain more realistic initial ocean conditions, including the position and structure of the Gulf Stream (GS) and Loop Current (LC), in the Geophysical Fluid Dynamics Laboratory/University of Rhode Island (GFDL/URI) coupled hurricane prediction system used operationally at the National Centers for Environmental Prediction. This procedure is based on a feature-modeling approach that allows a realistic simulation of the cross-frontal temperature, salinity, and velocity of oceanic fronts. While previous feature models used analytical formulas to represent frontal structures, the new procedure uses the innovative method of cross-frontal “sharpening” of the background temperature and salinity fields. The sharpening is guided by observed cross sections obtained in specialized field experiments in the GS. The ocean currents are spun up by integrating the ocean model for 2 days, which was sufficient for the velocity fields to adjust to the strong gradients of temperature and salinity in the main thermocline in the GS and LC. A new feature-modeling approach was also developed for the initialization of a multicurrent system in the Caribbean Sea, which provides the LC source. The initialization procedure is demonstrated for coupled model forecasts of Hurricane Isidore (2002).
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Xie, Xuetong, Jing Wang, and Mingsen Lin. "High Wind Geophysical Model Function Modeling for the HY-2A Scatterometer Using Neural Network." Remote Sensing 14, no. 10 (May 12, 2022): 2335. http://dx.doi.org/10.3390/rs14102335.
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Under low to medium wind speeds and no rainfall, the retrieved vector wind from a scatterometer is accurate and reliable. However, under high wind conditions, the currently used geophysical model function (GMF), such as NSCAT-2, for wind vector retrieval has the disadvantage of overestimating the backscattering coefficient, which leads to a decrease in the quality of the retrieved ocean surface winds. To enhance the wind retrieval precision of the HY-2A scatterometer under high wind conditions, a new GMF for high wind (HW-GMF) is established by using the neural network method based on the backscattering coefficient data of the HY-2A scatterometer combined with the wind speed data of the Special Sensor Microwave Imager (SSM/I) and the Final (FNL) operational global analysis wind direction data from the National Centers for Environmental Prediction (NCEP). The absolute value of the mean deviation between the predicted σ0 by the HW-GMF and the measured σ0 by the HY-2A scatterometer is less than 0.1 dB, indicating that the HW-GMF has high accuracy. To verify the HW-GMF performance, the wind field inversion accuracy of the HW-GMF is compared with that of the NSCAT-2 GMF, a GMF currently used in the data processing of the HY-2A scatterometer. The experimental results show that the deviation between the HW-GMF retrieved wind speed and the SSM/I wind speed is within 2 m/s in the high wind speed range of 15–35 m/s, indicating that the HW-GMF improves the precision of the wind speed inversion of the HY-2A scatterometer under high wind speed conditions.
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Ganiev, O. Z., T. A. Amashukeli, L. V. Farfuliak, and K. V. Petrenko. "Organization of the stationary seismological observations point." Geofizicheskiy Zhurnal 43, no. 5 (November 24, 2021): 232–40. http://dx.doi.org/10.24028/gzh.v43i5.244085.
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The Institute of Geophysics of the NASU organizes and carries out continuous regional and local seismic observations on the territory of Ukraine. The article presents a universal modern model of seismic activity monitoring process, which is used in most international seismological agencies (USGS, EMSC, NEIC) and describes a typical stationary point of seismological observations of the National Seismological Network of the Institute of Geophysics of NAS of Ukraine. Seismological network of observations is a complex of systems consisting of stationary seismological points of registration of seismic waves, the distributed system of transfer and collecting of the seismological information, and also the center of operative processing of the data arriving from data registration points. The process of conducting regime seismological observations of local and remote seismic events on the territory of Ukraine and adjacent regions is described. Some important aspects of the need for comprehensive processing of registered events to identify local earthquakes and assess the current activity of tectonic structures in Ukraine are presented. The seismological network of the National Seismological Center of the Institute of Geophysics of the National Academy of Sciences of Ukraine is represented by a small number of stationary observation points: «Kiev-IRIS», «MI02-Poltava», «MI03-Skvyra», «MI04-Dnipro», «MI05-Stepanivka», «MI07-Mykolaiv», «ODS-Odesa», «MIU-Kryvyi Rih», and «MI06-Kremenchug». This number of seismological observation points does not actually provide seismic observation data to the central, eastern and southern parts of the territory of Ukraine and does not allow to reliably determine the level and quantitative characteristics of its seismic hazard. The seismic recorder Guralp CMG-40T manufactured by the British company GURALP SYSTEMS LIMITED is offered as optimal for the conditions and financial realities of Ukraine when organizing a stationary seismic observation point. It is proposed to use the seismological processing package SeisComP, which works on the SeedLink protocol, which is the basis of the data collection system by the Internet. This software product is the de facto world standard in the field of seismological data processing.
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Wu, Mao-Fou, Marvin A. Geller, Jerry G. Olson, Alvin J. Miller, and Ronald M. Nagatani. "Computations of ozone transport using Nimbus 7 solar backscatter ultraviolet and NOAA/National Meteorological Center data." Journal of Geophysical Research 90, no. D3 (1985): 5745. http://dx.doi.org/10.1029/jd090id03p05745.
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Yeck, William Luther, John M. Patton, Zachary E. Ross, Gavin P. Hayes, Michelle R. Guy, Nick B. Ambruz, David R. Shelly, Harley M. Benz, and Paul S. Earle. "Leveraging Deep Learning in Global 24/7 Real-Time Earthquake Monitoring at the National Earthquake Information Center." Seismological Research Letters 92, no. 1 (September 23, 2020): 469–80. http://dx.doi.org/10.1785/0220200178.
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Abstract Machine-learning algorithms continue to show promise in their application to seismic processing. The U.S. Geological Survey National Earthquake Information Center (NEIC) is exploring the adoption of these tools to aid in simultaneous local, regional, and global real-time earthquake monitoring. As a first step, we describe a simple framework to incorporate deep-learning tools into NEIC operations. Automatic seismic arrival detections made from standard picking methods (e.g., short-term average/long-term average [STA/LTA]) are fed to trained neural network models to improve automatic seismic-arrival (pick) timing and estimate seismic-arrival phase type and source-station distances. These additional data are used to improve the capabilities of the NEIC associator. We compile a dataset of 1.3 million seismic-phase arrivals that represent a globally distributed set of source-station paths covering a range of phase types, magnitudes, and source distances. We train three separate convolutional neural network models to predict arrival time onset, phase type, and distance. We validate the performance of the trained networks on a subset of our existing dataset and further extend validation by exploring the model performance when applied to NEIC automatic pick data feeds. We show that the information provided by these models can be useful in downstream event processing, specifically in seismic-phase association, resulting in reduced false associations and improved location estimates.
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Bondár, István, Tereza Šindelářová, Daniela Ghica, Ulrike Mitterbauer, Alexander Liashchuk, Jiří Baše, Jaroslav Chum, et al. "Central and Eastern European Infrasound Network: contribution to infrasound monitoring." Geophysical Journal International 230, no. 1 (February 17, 2022): 565–79. http://dx.doi.org/10.1093/gji/ggac066.
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SUMMARY The Central and Eastern European Infrasound Network (CEEIN) has been established in 2018 with the collaboration of four research institutes, the Zentralanstalt für Meteorologie and Geodynamik (ZAMG), Vienna, Austria; the Institute of Atmospheric Physics of the Czech Academy of Sciences (CAS IAP), Prague, Czech Republic; the Research Centre for Astronomy and Earth Sciences of the Eötvös Loránd Research Network (ELKH CSFK), Budapest, Hungary; and the National Institute for Earth Physics (NIEP), Magurele, Romania. The Main Centre of Special Monitoring National Center for Control and Testing of Space Facilities, State Agency of Ukraine joined CEEIN in 2019. We show how the CEEIN infrasound arrays improve the detection capability of the European infrasound network and discuss coherent noise sources observed at CEEIN stations. We present the first CEEIN bulletin (2017–2020) of infrasound-only and seismo-acoustic events and using ground truth events, we demonstrate how adding infrasound observations to seismic data in the location algorithm improves location accuracy.
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Evans, Robert D., Irina Petropavlovskikh, Audra McClure-Begley, Glen McConville, Dorothy Quincy, and Koji Miyagawa. "Technical note: The US Dobson station network data record prior to 2015, re-evaluation of NDACC and WOUDC archived records with WinDobson processing software." Atmospheric Chemistry and Physics 17, no. 19 (October 11, 2017): 12051–70. http://dx.doi.org/10.5194/acp-17-12051-2017.
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Abstract. The United States government has operated Dobson ozone spectrophotometers at various sites, starting during the International Geophysical Year (1 July 1957 to 31 December 1958). A network of stations for long-term monitoring of the total column content (thickness of the ozone layer) of the atmosphere was established in the early 1960s and eventually grew to 16 stations, 14 of which are still operational and submit data to the United States of America's National Oceanic and Atmospheric Administration (NOAA). Seven of these sites are also part of the Network for the Detection of Atmospheric Composition Change (NDACC), an organization that maintains its own data archive. Due to recent changes in data processing software the entire dataset was re-evaluated for possible changes. To evaluate and minimize potential changes caused by the new processing software, the reprocessed data record was compared to the original data record archived in the World Ozone and UV Data Center (WOUDC) in Toronto, Canada. The history of the observations at the individual stations, the instruments used for the NOAA network monitoring at the station, the method for reducing zenith-sky observations to total ozone, and calibration procedures were re-evaluated using data quality control tools built into the new software. At the completion of the evaluation, the new datasets are to be published as an update to the WOUDC and NDACC archives, and the entire dataset is to be made available to the scientific community. The procedure for reprocessing Dobson data and the results of the reanalysis on the archived record are presented in this paper. A summary of historical changes to 14 station records is also provided.
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Roger, Jean, Bernard Pelletier, and Jérôme Aucan. "Update of the tsunami catalogue of New Caledonia using a decision table based on seismic data and marigraphic records." Natural Hazards and Earth System Sciences 19, no. 7 (July 22, 2019): 1471–83. http://dx.doi.org/10.5194/nhess-19-1471-2019.
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Abstract. Fourteen years ago, the 26 December 2004 Indian Ocean tsunami demonstrated the destructional capability of tsunamis to the entire world. Since then, many research programs have been initiated to try to understand the phenomenon and its related hazards better and to improve the early warning systems for exposed coastal populations. Pacific Islands Countries and Territories (PICTs) are especially vulnerable to tsunamis. Amongst them, New Caledonia is a French overseas territory located in the Southwest Pacific and exposed to several tsunami sources. In 2010, a catalogue of tsunamis that were visually observed or measured in New Caledonia was published. Since this first study, several events occurred between 2009 and 2019, and an update of this catalogue was necessary within the framework of a tsunami hazard assessment project in New Caledonia (TSUCAL). To complete this catalogue, a decision table has been designed to select potential tsunamigenic events within the USGS earthquake database, using criteria on the distance to New Caledonia, the magnitude and the hypocenter depth. Then a cross-comparison between these earthquakes, the NOAA National Geophysical Data Center (NGDC) tsunami catalogue and local tide gauge records provided 25 events that were recorded in New Caledonia for the period from 30 September 2009 to 10 January 2019. These events are added to the 12 events reported with certainty during previous studies, leading to a number of 37 tsunamis triggered by earthquakes reported or recorded in New Caledonia since 1875. Six of them have been identified only thanks to local tide gauges, supporting the fact that instrumental recording of tsunamis is paramount for tsunami hazard studies, from early warning to the validation of coastal models. In addition, unpublished tide gauge data are provided for the 1960 Chile tsunami.
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Wang, Gefei, Xiaowen Zhang, and Shiqiang Zhang. "Performance of Three Reanalysis Precipitation Datasets over the Qinling-Daba Mountains, Eastern Fringe of Tibetan Plateau, China." Advances in Meteorology 2019 (January 23, 2019): 1–16. http://dx.doi.org/10.1155/2019/7698171.
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Evaluation of different reanalysis precipitation datasets is of great importance to understanding the hydrological processes and water resource management practice in the Qinling-Daba Mountains (QDM), located at the eastern fringe of the Tibetan Plateau. Although the evaluation of satellite precipitation data in this region has been performed, another kind of popular precipitation product-reanalysis dataset has not been assessed in depth. Three popular reanalysis precipitation datasets, including ERA-Interim Reanalysis of European Centre for Medium Forecasts (ERA-Interim), Japanese 55-year Reanalysis (JRA-55), and National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis-1 (NCEP/NCAR-1) were evaluated against rain gauge data over the Qinling-Daba Mountains from 2000 to 2014 on monthly, seasonal, and annual scales. Different statistical measures based on the Correlation Coefficient (CC), relative BIAS (BIAS), Root-Mean-Square Error (RMSE), and Mean Absolute Error (MAE) were adopted to determine the performance of the above reanalysis datasets. Results show that ERA-Interim and JRA-55 have good performance on a monthly scale and annual scale. However, the NCEP/NCAR-1 has the least BIAS with the observed precipitation in annual scale in QDM. All reanalysis datasets performed better in spring, summer, and autumn than in winter. The advantages of involving more precipitation observation stations was probably the main reason of the different performance of three precipitation reanalysis products, and the benefit of a four-dimensional variational analysis model over a three-dimensional variational analysis model may be another reason. The evaluation suggested that ERA-Interim is more suitable for study the precipitation and water cycles in the QDM.
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JAIN, PANKAJ, ASHOK KUMAR, PARVINDER MAINI, and S. V. SINGH. "Short range SW monsoon rainfall forecasting over India using neural networks." MAUSAM 53, no. 2 (January 18, 2022): 225–32. http://dx.doi.org/10.54302/mausam.v53i2.1637.
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Feedforward Neural Networks are used for daily precipitation forecast using several test stations all over India. The six year European Centre of Medium Range Weather Forecasting (ECMWF) data is used with the training set consisting of the four year data from 1985-1988 and validation set consisting of the data from 1989-1990. Neural networks are used to develop a concurrent relationship between precipitation and other atmospheric variables. No attempt is made to select optimal variables for this study and the inputs are chosen to be same as the ones obtained earlier at National Center for Medium Range Weather Forecasting (NCMRWF) in developing a linear regression model. Neural networks are found to yield results which are atleast as good as linear regression and in several cases yield 10 - 20 % improvement. This is encouraging since the variable selection has so far been optimized for linear regression.