Searched for: author%3A%22Klees%2C+R.%22
(1 - 20 of 64)

Pages

document
Klees, R. (author), Seitz, Kurt (author), Slobbe, D.C. (author)
We present exact, closed-form expressions for the complete RTM correction and the harmonic correction to disturbing potential, gravity disturbance, gravity anomaly, and height anomaly. They need to be applied in quasi-geoid modelling whenever data points are buried inside the masses after residual terrain model (RTM) reduction and...
journal article 2023
document
Klees, R. (author), Slobbe, D.C. (author)
This paper investigates the full variance–covariance (VC) matrix of two high-resolution regional quasi-geoid models, utilizing a spherical radial basis function parameterization. Model parameters were estimated using weighted least-squares techniques and variance component estimation (VCE) for data weighting. The first model, known as the ...
journal article 2023
document
Afrasteh, Y. (author), Slobbe, D.C. (author), Verlaan, M. (author), Klees, R. (author), Guarneri, H. (author), Keyzer, L.M. (author), Pietrzak, J.D. (author), Sacher, M. (author), Snellen, M. (author), Zijl, F. (author)
The main objective of this study is to develop and analyze an empirical noise model for model-derived coastal summer mean water levels (SMWLs) and use that to obtain a more realistic quality impact of combining hydrodynamic leveling and Unified European Leveling Network (UELN) data in realizing the European Vertical Reference System (EVRS)....
journal article 2023
document
Guarneri, H. (author), Verlaan, M. (author), Slobbe, D.C. (author), Veenstra, J. (author), Zijl, F. (author), Pietrzak, J.D. (author), Snellen, M. (author), Keyzer, L.M. (author), Afrasteh, Y. (author), Klees, R. (author)
Both empirical and assimilative global ocean tidal models are significantly more accurate in the deep ocean than in shelf and coastal waters. In this study, we answered whether this is due to the quality of the models used to reduce tide and surge or the general approach to treat tide and surge as two separate components of the water level...
journal article 2023
document
Afrasteh, Y. (author), Slobbe, D.C. (author), Sacher, M. (author), Verlaan, M. (author), Klees, R. (author), Guarneri, H. (author), Keyzer, L.M. (author), Pietrzak, J.D. (author), Snellen, M. (author)
All realizations of the European Vertical Reference System (EVRS) computed so far are solely based on geopotential differences obtained by spirit leveling/gravimetry. As such, there are no direct connections between height benchmarks separated by large water bodies. In this study, such connections are added by means of model-based...
journal article 2023
document
Guarneri, H. (author), Verlaan, M. (author), Slobbe, D.C. (author), Zijl, Firmijn (author), Pietrzak, J.D. (author), Keyzer, L.M. (author), Klees, R. (author)
Satellite observations can help in the retrieval of constituents in shallow waters. Noise contamination, however, makes smaller constituents irretrievable and large sources of error. Throughout shallow areas, the constituent’s relevancy changes. For example, near an amphidromic point where M2 relevance drops, so does the potential of satellite...
poster 2022
document
Li, X. (author), Huang, J. (author), Klees, R. (author), Forsberg, R. (author), Willberg, M. (author), Slobbe, D.C. (author), Hwang, C. (author), Pail, R. (author)
In this study, we compare six commonly used methods for the downward continuation of airborne gravity data. We consider exact and noisy simulated data on grids and along flight trajectories and real data from the GRAV-D airborne campaign. We use simulated and real surface gravity data for validation. The methods comprise spherical harmonic...
journal article 2022
document
Klees, R. (author), Seitz, K. (author), Slobbe, D.C. (author)
In this paper, we derive improved expressions for the harmonic correction to gravity and, for the first time, expressions for the harmonic correction to potential and height anomaly. They need to be applied at stations buried inside the masses to transform internal values into harmonically downward continued values, which are then input to...
journal article 2022
document
Keyzer, L.M. (author), Mohammadloo, Tannaz H. (author), Snellen, M. (author), Pietrzak, J.D. (author), Katsman, C.A. (author), Afrasteh, Y. (author), Guarneri, H. (author), Verlaan, M. (author), Klees, R. (author), Slobbe, D.C. (author)
The sound speed provides insight in ocean properties, as it depends on depth, temperature and salinity. Here, we propose a method to invert sound speed profiles (SSPs) from multibeam echosounder (MBES) measurements, providing a SSP for every ping. Using erroneous SSPs results in a mismatch in the estimated bathymetry between overlapping swaths....
book chapter 2021
document
Afrasteh, Y. (author), Slobbe, D.C. (author), Verlaan, M. (author), Sacher, M. (author), Klees, R. (author), Guarneri, H. (author), Keyzer, L.M. (author), Pietrzak, J.D. (author), Snellen, M. (author), Zijl, F. (author)
The first objective of this paper is to assess by means of geodetic network analyses the impact of adding model-based hydrodynamic leveling data to the Unified European Leveling Network (UELN) data on the precision and reliability of the European Vertical Reference Frame (EVRF). In doing so, we used variance information from the latest UELN...
journal article 2021
document
Kleptsova, Olga S. (author), Dijkstra, Henk A. (author), van Westen, René M. (author), van der Boog, C.G. (author), Katsman, C.A. (author), James, Rebecca K. (author), Bouma, Tjeerd J. (author), Klees, R. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), Zijlema, Marcel (author), Pietrzak, J.D. (author)
Joint effects of the dynamic sea-level rise projected changes in the large-scale atmosphere/ocean circulation, and wave climate on hurricane-induced extreme water levels in the Caribbean region are assessed. We use the 2D-depth integrated ADCIRC + SWAN wave-ocean model, baroclinically coupled to an ocean-eddying version of the Community Earth...
journal article 2021
document
Ran, Jiangjun (author), Ditmar, P.G. (author), Liu, Lin (author), Xiao, Yun (author), Klees, R. (author), Tang, Xueyuan (author)
Mascon products derived from Gravity Recovery and Climate Experiment satellite gravimetry data are widely used to study the Greenland ice sheet mass balance. However, the products released by different research groups—JPL, CSR, and GSFC—show noticeable discrepancies. To understand them, we compare those mascon products with mascon solutions...
journal article 2021
document
James, R.K. (author), Lynch, A. (author), Herman, P.M.J. (author), van Katwijk, M.M. (author), van Tussenbroek, B.I. (author), Dijkstra, H.A. (author), van Westen, R. M. (author), van der Boog, C.G. (author), Klees, R. (author), Pietrzak, J.D. (author), Slobbe, D.C. (author), Bouma, T.J. (author)
The intensity of major storm events generated within the Atlantic Basin is projected to rise with the warming of the oceans, which is likely to exacerbate coastal erosion. Nature-based flood defence has been proposed as a sustainable and effective solution to protect coastlines. However, the ability of natural ecosystems to withstand major...
journal article 2021
document
van Westen, René M. (author), Dijkstra, Henk A. (author), van der Boog, C.G. (author), Katsman, C.A. (author), James, Rebecca K. (author), Bouma, T.J. (author), Kleptsova, Olga (author), Klees, R. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), Zijlema, Marcel (author), Pietrzak, J.D. (author)
Sea-level rise poses severe threats to coastal and low-lying regions around the world, by exacerbating coastal erosion and flooding. Adequate sea-level projections over the next decades are important for both decision making and for the development of successful adaptation strategies in these coastal and low-lying regions to climate change....
journal article 2020
document
Reudink, R.H.C. (author), Klees, R. (author), Alberts, Bas (author), Van Waarden, Pieter (author)
The backbone of the Amsterdam Ordnance Datum (NAP) is a network of about 400 primary subsurface markers. Relative movements between the primary subsurface markers are measured with spirit levelling once in 10-20 years. However, little is known about absolute vertical movements of the primary network. This information is indispensable for the...
journal article 2020
document
Slobbe, D.C. (author), Klees, R. (author), Farahani, H. (author), Huisman, L. (author), Alberts, Bas (author), Voet, Pierre (author), Doncker, Filip De (author)
We present a local quasi-geoid (QG) model which combines a satellite-only global gravity model with local data sets using weighted least squares. The QG is computed for an area comprising the Netherlands, Belgium, and the southern North Sea. It uses a two-scale spherical radial basis function model complemented by bias parameters to account...
journal article 2019
document
Groh, Andreas (author), Horwath, Martin (author), Horvath, Alexander (author), Meister, Rakia (author), Wouters, B. (author), Ditmar, P.G. (author), Ran, J. (author), Klees, R. (author), Schrama, Ernst (author)
Satellite gravimetry data acquired by the Gravity Recovery and Climate Experiment (GRACE) allows to derive the temporal evolution in ice mass for both the Antarctic Ice Sheet (AIS) and the Greenland Ice Sheet (GIS). Various algorithms have been used in a wide range of studies to generate Gravimetric Mass Balance (GMB) products. Results from...
journal article 2019
document
James, Rebecca K. (author), Pietrzak, J.D. (author), Candy, A.S. (author), Katsman, C.A. (author), van der Boog, C.G. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), Klees, R. (author)
Tropical beaches provide coastal flood protection, income from tourism, and habitat for flagship species. They urgently need protection from erosion, which is being exacerbated by changing climate and coastal development. Traditional coastal engineering solutions are expensive, provide unstable temporary solutions, and often disrupt natural...
journal article 2019
document
James, Rebecca K. (author), van Katwijk, Marieke M. (author), Pietrzak, J.D. (author), Candy, A.S. (author), Klees, R. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), Katsman, C.A. (author), Herman, P.M.J. (author)
Global oceanic pH is lowering, which is causing great concern for the natural functioning of marine ecosystems. Current pH predictions are based on open ocean models; however, coastal zones are dynamic systems with seawater pH fluctuating temporally and spatially. To understand how coastal ecosystems will respond in the future, we first need...
journal article 2019
document
van der Boog, C.G. (author), Pietrzak, J.D. (author), Dijkstra, Henk A. (author), Brüggemann, N. (author), Van Westen, René M. (author), James, Rebecca K. (author), Bouma, Tjeerd J. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), Klees, R. (author), Zijlema, Marcel (author), Katsman, C.A. (author)
The mesoscale variability in the Caribbean Sea is dominated by anticyclonic eddies that are formed in the eastern part of the basin. These anticyclones intensify on their path westward while they pass the coastal upwelling region along the Venezuelan and Colombian coast. In this study, we used a regional model to show that this westward...
journal article 2019
Searched for: author%3A%22Klees%2C+R.%22
(1 - 20 of 64)

Pages