scholarly journals Using the Nordic Geodetic Observing System for land uplift studies

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 673-681 ◽  
Author(s):  
M. Nordman ◽  
M. Poutanen ◽  
A. Kairus ◽  
J. Virtanen
Keyword(s):  
International Association ◽  
Data Availability ◽  
Absolute Gravity ◽  
Data Sets ◽  
Land Uplift ◽  
Mantle Dynamics ◽  
Quaternary Climate ◽  
General Data ◽  
Supplementary Material ◽  
Observing Systems

Abstract. Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the data sets. Globally, there is the International Association of Geodesy (IAG) Global Geodetic Observing System (GGOS), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, the Nordic Geodetic Observing System (NGOS) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss in general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such a database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravity, with the Nordic Geodetic Commission NKG2005LU land uplift model for Fennoscandia. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. The primary aim of observing systems will be to produce data and other products needed by multidisciplinary projects, such as Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas (DynaQlim) or the European Plate Observing System (EPOS), but their needs may currently exceed the scope of an existing observing system. We discuss what requirements the projects pose to observing systems and their development. To make comparisons between different studies possible and reliable, the researcher should document what they have in detail, either in appendixes, supplementary material or some other available format.

scholarly journals Using the Nordic Geodetic Observing System for land uplift studies

2014 ◽  
Vol 6 (1) ◽  
pp. 377-401
Author(s):  
M. Nordman ◽  
M. Poutanen ◽  
A. Kairus ◽  
J. Virtanen
Keyword(s):  
Upper Mantle ◽  
Data Availability ◽  
Tide Gauges ◽  
Land Uplift ◽  
Mantle Dynamics ◽  
Quaternary Climate ◽  
Regional System ◽  
General Data ◽  
Different Sources ◽  
Observing Systems

Abstract. Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the datasets. Globally, there is the IAG GGOS (Global Geodetic Observing System), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, NGOS (Nordic Geodetic Observing System) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss on general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravimeter, with the Nordic NKG2005LU land uplift model. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. It is also important to consider the relation between geodetic observing systems and specific projects like DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) or EPOS (European Plate Observing System). The natural aim of observing systems will be to produce data and other products needed by such multidisciplinary projects, but their needs may currently exceed the scope of an observing system. We discuss what requirements the projects pose to observing systems and their development.

scholarly journals Forty-three years of absolute gravity observations of the Fennoscandian postglacial rebound in Finland

2021 ◽  
Vol 95 (2) ◽  
Author(s):  
Mirjam Bilker-Koivula ◽  
Jaakko Mäkinen ◽  
Hannu Ruotsalainen ◽  
Jyri Näränen ◽  
Timo Saari
Keyword(s):  
Gravity Data ◽  
Gravity Change ◽  
Global Navigation Satellite Systems ◽  
Absolute Gravity ◽  
Data Sets ◽  
Postglacial Rebound ◽  
Land Uplift ◽  
Satellite Systems ◽  
Gravity Measurements ◽  
Global Navigation Satellite

AbstractPostglacial rebound in Fennoscandia causes striking trends in gravity measurements of the area. We present time series of absolute gravity data collected between 1976 and 2019 on 12 stations in Finland with different types of instruments. First, we determine the trends at each station and analyse the effect of the instrument types. We estimate, for example, an offset of 6.8 μgal for the JILAg-5 instrument with respect to the FG5-type instruments. Applying the offsets in the trend analysis strengthens the trends being in good agreement with the NKG2016LU_gdot model of gravity change. Trends of seven stations were found robust and were used to analyse the stabilization of the trends in time and to determine the relationship between gravity change rates and land uplift rates as measured with global navigation satellite systems (GNSS) as well as from the NKG2016LU_abs land uplift model. Trends calculated from combined and offset-corrected measurements of JILAg-5- and FG5-type instruments stabilized in 15 to 20 years and at some stations even faster. The trends of FG5-type instrument data alone stabilized generally within 10 years. The ratio between gravity change rates and vertical rates from different data sets yields values between − 0.206 ± 0.017 and − 0.227 ± 0.024 µGal/mm and axis intercept values between 0.248 ± 0.089 and 0.335 ± 0.136 µGal/yr. These values are larger than previous estimates for Fennoscandia.

scholarly journals The semiannual oscillation (SAO) in the tropical middle atmosphere and its gravity wave driving in reanalyses and satellite observations

2021 ◽  
Vol 21 (18) ◽  
pp. 13763-13795
Author(s):  
Manfred Ern ◽  
Mohamadou Diallo ◽  
Peter Preusse ◽  
Martin G. Mlynczak ◽  
Michael J. Schwartz ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Gravity Waves ◽  
Wave Drag ◽  
Satellite Observations ◽  
Absolute Gravity ◽  
Data Sets ◽  
Background Wind ◽  
Wind Climatology ◽  
Basic Features ◽  
Semiannual Oscillation

Abstract. Gravity waves play a significant role in driving the semiannual oscillation (SAO) of the zonal wind in the tropics. However, detailed knowledge of this forcing is missing, and direct estimates from global observations of gravity waves are sparse. For the period 2002–2018, we investigate the SAO in four different reanalyses: ERA-Interim, JRA-55, ERA-5, and MERRA-2. Comparison with the SPARC zonal wind climatology and quasi-geostrophic winds derived from Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite observations show that the reanalyses reproduce some basic features of the SAO. However, there are also large differences, depending on the model setup. Particularly, MERRA-2 seems to benefit from dedicated tuning of the gravity wave drag parameterization and assimilation of MLS observations. To study the interaction of gravity waves with the background wind, absolute values of gravity wave momentum fluxes and a proxy for absolute gravity wave drag derived from SABER satellite observations are compared with different wind data sets: the SPARC wind climatology; data sets combining ERA-Interim at low altitudes and MLS or SABER quasi-geostrophic winds at high altitudes; and data sets that combine ERA-Interim, SABER quasi-geostrophic winds, and direct wind observations by the TIMED Doppler Interferometer (TIDI). In the lower and middle mesosphere the SABER absolute gravity wave drag proxy correlates well with positive vertical gradients of the background wind, indicating that gravity waves contribute mainly to the driving of the SAO eastward wind phases and their downward propagation with time. At altitudes 75–85 km, the SABER absolute gravity wave drag proxy correlates better with absolute values of the background wind, suggesting a more direct forcing of the SAO winds by gravity wave amplitude saturation. Above about 80 km SABER gravity wave drag is mainly governed by tides rather than by the SAO. The reanalyses reproduce some basic features of the SAO gravity wave driving: all reanalyses show stronger gravity wave driving of the SAO eastward phase in the stratopause region. For the higher-top models ERA-5 and MERRA-2, this is also the case in the lower mesosphere. However, all reanalyses are limited by model-inherent damping in the upper model levels, leading to unrealistic features near the model top. Our analysis of the SABER and reanalysis gravity wave drag suggests that the magnitude of SAO gravity wave forcing is often too weak in the free-running general circulation models; therefore, a more realistic representation is needed.

scholarly journals Homogenisation of a gridded snow water equivalent climatology for Alpine terrain: methodology and applications

2014 ◽  
Vol 8 (2) ◽  
pp. 471-485 ◽  
Author(s):  
S. Jörg-Hess ◽  
F. Fundel ◽  
T. Jonas ◽  
M. Zappa
Keyword(s):  
Land Surface ◽  
Snow Water Equivalent ◽  
Winter Season ◽  
Data Availability ◽  
Model Systems ◽  
Added Value ◽  
Data Sets ◽  
Atmospheric Models ◽  
Catchment Areas ◽  
Snow Water

Abstract. Gridded snow water equivalent (SWE) data sets are valuable for estimating the snow water resources and verify different model systems, e.g. hydrological, land surface or atmospheric models. However, changing data availability represents a considerable challenge when trying to derive consistent time series for SWE products. In an attempt to improve the product consistency, we first evaluated the differences between two climatologies of SWE grids that were calculated on the basis of data from 110 and 203 stations, respectively. The "shorter" climatology (2001–2009) was produced using 203 stations (map203) and the "longer" one (1971–2009) 110 stations (map110). Relative to map203, map110 underestimated SWE, especially at higher elevations and at the end of the winter season. We tested the potential of quantile mapping to compensate for mapping errors in map110 relative to map203. During a 9 yr calibration period from 2001 to 2009, for which both map203 and map110 were available, the method could successfully refine the spatial and temporal SWE representation in map110 by making seasonal, regional and altitude-related distinctions. Expanding the calibration to the full 39 yr showed that the general underestimation of map110 with respect to map203 could be removed for the whole winter. The calibrated SWE maps fitted the reference (map203) well when averaged over regions and time periods, where the mean error is approximately zero. However, deviations between the calibrated maps and map203 were observed at single grid cells and years. When we looked at three different regions in more detail, we found that the calibration had the largest effect in the region with the highest proportion of catchment areas above 2000 m a.s.l. and that the general underestimation of map110 compared to map203 could be removed for the entire snow season. The added value of the calibrated SWE climatology is illustrated with practical examples: the verification of a hydrological model, the estimation of snow resource anomalies and the predictability of runoff through SWE.

scholarly journals A general end-to-end diagnosis framework for manufacturing systems

2019 ◽  
Vol 7 (2) ◽  
pp. 418-429 ◽  
Author(s):  
Ye Yuan ◽  
Guijun Ma ◽  
Cheng Cheng ◽  
Beitong Zhou ◽  
Huan Zhao ◽  
...  
Keyword(s):  
Deep Learning ◽  
Manufacturing Systems ◽  
Time Course ◽  
Manufacturing Sector ◽  
Smart Manufacturing ◽  
Data Sets ◽  
Learning Techniques ◽  
General Data ◽  
End To End ◽  
Manufacturing Applications

Abstract The manufacturing sector is envisioned to be heavily influenced by artificial-intelligence-based technologies with the extraordinary increases in computational power and data volumes. A central challenge in the manufacturing sector lies in the requirement of a general framework to ensure satisfied diagnosis and monitoring performances in different manufacturing applications. Here, we propose a general data-driven, end-to-end framework for the monitoring of manufacturing systems. This framework, derived from deep-learning techniques, evaluates fused sensory measurements to detect and even predict faults and wearing conditions. This work exploits the predictive power of deep learning to automatically extract hidden degradation features from noisy, time-course data. We have experimented the proposed framework on 10 representative data sets drawn from a wide variety of manufacturing applications. Results reveal that the framework performs well in examined benchmark applications and can be applied in diverse contexts, indicating its potential use as a critical cornerstone in smart manufacturing.

The Winter Monsoon Experiment—Report of December 1978 Field Phase

1979 ◽  
Vol 60 (5) ◽  
pp. 439-444 ◽  
Author(s):  
Richard S. Greenfield ◽  
T. N. Krishnamurti
Keyword(s):  
The Philippines ◽  
Winter Monsoon ◽  
Data Sets ◽  
Preliminary Evaluation ◽  
Kuala Lumpur ◽  
Field Phase ◽  
Republic Of China ◽  
Technical Personnel ◽  
Short Summary ◽  
Observing Systems

These notes provide a short summary of the field phase of the GARP Winter Monsoon Experiment. The field phase commenced on 1 December 1978, with the field operations coordinated from Kuala Lumpur. The participants included scientists and technical personnel from Malaysia, Indonesia, Thailand, the Philippines, Hong Kong, Japan, Saudi Arabia, Singapore, Australia, People's Republic of China (PRC), the U.S.S.R., and the U.S.A. The observing systems, type of experiments, mission objectives, components of overall data sets, and a preliminary evaluation are presented in this short survey.

scholarly journals Kernel Treelets

2019 ◽  
Vol 11 (03n04) ◽  
pp. 1950006
Author(s):  
Hedi Xia ◽  
Hector D. Ceniceros
Keyword(s):  
Hierarchical Clustering ◽  
Reproducing Kernel ◽  
Reproducing Kernel Hilbert Space ◽  
Feature Space ◽  
Coefficient Matrix ◽  
Data Sets ◽  
Clustering Methods ◽  
Orthonormal Bases ◽  
Data Points ◽  
General Data

A new method for hierarchical clustering of data points is presented. It combines treelets, a particular multiresolution decomposition of data, with a mapping on a reproducing kernel Hilbert space. The proposed approach, called kernel treelets (KT), uses this mapping to go from a hierarchical clustering over attributes (the natural output of treelets) to a hierarchical clustering over data. KT effectively substitutes the correlation coefficient matrix used in treelets with a symmetric and positive semi-definite matrix efficiently constructed from a symmetric and positive semi-definite kernel function. Unlike most clustering methods, which require data sets to be numeric, KT can be applied to more general data and yields a multiresolution sequence of orthonormal bases on the data directly in feature space. The effectiveness and potential of KT in clustering analysis are illustrated with some examples.

Sign in / Sign up

Export Citation Format

Share Document