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ESA's ice sheets CCI: Validation and inter-comparison of surface elevation changes derived

Levinsen, J.F. (author), Khvorostovsky, K. (author), Ticconi, F. (author), Shepherd, A. (author), Forsberg, R. (author), Sørensen, L.S. (author), Muir, A. (author), Pie, N. (author), Felikson, D. (author), Flament, T. (author), Hurkmans, R. (author), Moholdt, G. (author), Gunter, B.C. (author), Lindenbergh, R.C. (author), Kleinherenbrink, M. (author)

In order to increase the understanding of the changing climate, the European Space Agency has launched the Climate Change Initiative (ESA CCI), a program which joins scientists and space agencies into 13 projects either affecting or affected by the concurrent changes. 5 This work is part of the Ice Sheets CCI and four parameters are to be...

journal article 2013

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Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean

Kleinherenbrink, M. (author), Riva, R.E.M. (author), Sun, Y. (author)

. In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and Argo, full variance–covariance matrices are...

journal article 2016

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Closing the sea level budget on a regional scale: Trends and variability on the Northwestern European continental shelf

Frederikse, T. (author), Riva, R.E.M. (author), Kleinherenbrink, M. (author), Wada, Yoshihide (author), van den Broeke, Michiel (author), Marion, Ben (author)

Long-term trends and decadal variability of sea level in the North Sea and along the Norwegian coast have been studied over the period 1958–2014. We model the spatially nonuniform sea level and solid earth response to large-scale ice melt and terrestrial water storage changes. GPS observations, corrected for the solid earth deformation, are used...

journal article 2016

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A data-driven model for constraint of present-day glacial isostatic adjustment in North America

Simon, K.M. (author), Riva, R.E.M. (author), Kleinherenbrink, M. (author), Tangdamrongsub, N. (author)

Geodetic measurements of vertical land motion and gravity change are incorporated into an a priori model of present-day glacial isostatic adjustment (GIA) in North America via least-squares adjustment. The result is an updated GIA model wherein the final predicted signal is informed by both observational data, and prior knowledge (or...

journal article 2017

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Lake seasonality across the Tibetan Plateau and their varying relationship with regional mass changes and local hydrology

Lei, Yanbin (author), Yao, Tandong (author), Yang, Kun (author), Sheng, Yongwei (author), Kleinherenbrink, M. (author), Yi, Shuang (author), Bird, Broxton W. (author), Zhang, Xiaowen (author), Zhu, La (author), Zhang, Guoqing (author)

The recent growth and deepening of inland lakes in the Tibetan Plateau (TP) may be a salient indicator of the consequences of climate change. The seasonal dynamics of these lakes is poorly understood despite this being potentially crucial for disentangling contributions from glacier melt and precipitation, which are all sensitive to climate,...

journal article 2017

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Trends and interannual variability of mass and steric sea level in the Tropical Asian Seas

Kleinherenbrink, M. (author), Riva, R.E.M. (author), Frederikse, T. (author), Merrifield, Mark (author), Wada, Yoshihide (author)

The mass and steric components of sea level changes have been separated in the Tropical Asian Seas (TAS) using a statistically optimal combination of Jason satellite altimetry, GRACE satellite gravimetry, and ocean reanalyses. Using observational uncertainties, statistically optimally weighted time series for both components have been...

journal article 2017

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A comparison of methods to estimate vertical land motion trends from GNSS and altimetry at tide gauge stations

Kleinherenbrink, M. (author), Riva, R.E.M. (author), Frederikse, T. (author)

Tide gauge (TG) records are affected by vertical land motion (VLM), causing them to observe relative instead of geocentric sea level. VLM can be estimated from global navigation satellite system (GNSS) time series, but only a few TGs are equipped with a GNSS receiver. Hence, (multiple) neighboring GNSS stations can be used to estimate VLM at...

journal article 2018

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The glacial isostatic adjustment signal at present day in northern Europe and the British Isles estimated from geodetic observations and geophysical models

Simon, K.M. (author), Riva, R.E.M. (author), Kleinherenbrink, M. (author), Frederikse, T. (author)

The glacial isostatic adjustment (GIA) signal at present day is constrained via the joint inversion of geodetic observations and GIA models for a region encompassing northern Europe, the British Isles, and the Barents Sea. The constraining data are Global Positioning System (GPS) vertical crustal velocities and GRACE (Gravity Recovery and...

journal article 2018

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Sea-level change in the Dutch Wadden Sea

Vermeersen, L.L.A. (author), Baart, F. (author), Cohen, Kim M. (author), Frederikse, T. (author), Kiden, Patrick (author), Kleinherenbrink, M. (author), Riva, R.E.M. (author), Slobbe, D.C. (author), van der Wegen, M. (author)

Rising sea levels due to climate change can have severe consequences for coastal populations and ecosystems all around the world. Understanding and projecting sea-level rise is especially important for low-lying countries such as the Netherlands. It is of specific interest for vulnerable ecological and morphodynamic regions, such as the...

journal article 2018

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A revised acceleration rate from the altimetry-derived global mean sea level record

Kleinherenbrink, M. (author), Riva, R.E.M. (author), Scharroo, Remko (author)

Satellite radar altimetry has been providing estimates of global mean sea level (GMSL) since 1992. The early TOPEX record originates from two identical instruments, which requires the estimation of an intermission bias and careful handling of the problematic first part of the record. Calibration of TOPEX is crucial to obtain a continuous and...

journal article 2019

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The second-order effect of Earth’s rotation on Cryosat-2 fully focused SAR processing

Kleinherenbrink, M. (author), Smith, Walter H.F. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Hoogeboom, P. (author)

We investigated the sensitivity of fully focused SAR (FF-SAR) processing of Cryosat-2 altimeter data to Earth rotation. Earth’s rotation causes scatterers at varying cross-track locations to have a different relative velocity with respect to the satellite. This second-order effect of Earth rotation on the phase is currently not corrected for...

journal article 2020

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The performance of CryoSat-2 fully-focussed SAR for inland water-level estimation

Kleinherenbrink, M. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Egido, Alejandro (author), Smith, Walter (author)

This paper applies the Fully-Focussed SAR (FF-SAR) algorithm to CryoSat-2 full-bit-rate data to measure water levels of lakes and canals in the Netherlands, and validates these measurements by comparing them to heights measured by gauges. Over Lake IJssel, a medium-sized lake, the FF-SAR height is biased about 6 cm below the gauge height, and...

journal article 2020

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Estimating instantaneous sea-ice dynamics from space using the bi-static radar measurements of Earth Explorer 10 candidate Harmony

Kleinherenbrink, M. (author), Korosov, Anton (author), Newman, Thomas (author), Theodosiou, A. (author), Komarov, Alexander S. (author), Li, Y. (author), Mulder, G. (author), Rampal, Pierre (author), Stroeve, Julienne (author), Lopez Dekker, F.J. (author)

This article describes the observation techniques and suggests processing methods to estimate dynamical sea-ice parameters from data of the Earth Explorer 10 candidate Harmony. The two Harmony satellites will fly in a reconfigurable formation with Sentinel-1D. Both will be equipped with a multi-angle thermal infrared sensor and a passive...

journal article 2021

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SAR altimetry data as a new source for swell monitoring

Altiparmaki, O. (author), Kleinherenbrink, M. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Visser, P.N.A.M. (author)

This article shows the first spectral analysis of fully-focused Synthetic Aperture Radar (FFSAR) altimetry data with the objective of studying backscatter modulations caused by swells. Swell waves distort the backscatter in altimetry radargrams by means of velocity and range bunching. These swell signatures are visible in the tail of the...

journal article 2022

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Wind-Wave Attenuation in Arctic Sea Ice: A Discussion of Remote Sensing Capabilities

Collard, Fabrice (author), Marié, Louis (author), Nouguier, Frédéric (author), Kleinherenbrink, M. (author), Ehlers, F. (author), Ardhuin, Fabrice (author)

Wind-generated waves strongly interact with sea ice and impact air-sea exchanges, operations at sea, and marine life. Unfortunately, the dissipation of wave energy is not well quantified and its possible effect on upper ocean mixing and ice drift is still mysterious. As the Arctic is opening up and wave energy increases, the limited amount of...

journal article 2022

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Validity assessment of SAMOSA retracking for fully-focused SAR altimeter waveforms

Ehlers, F. (author), Schlembach, Florian (author), Kleinherenbrink, M. (author), Slobbe, D.C. (author)

We demonstrate in this work how we can take advantage of known unfocused SAR (UF-SAR) retracking methods (e.g. the physical SAMOSA model) for retracking of fully-focused SAR (FF-SAR) waveforms. Our insights are an important step towards consistent observations of sea surface height, significant wave height and backscatter coefficient (wind...

journal article 2023

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Benefits of fully focused SAR altimetry to coastal wave height estimates: A case study in the North Sea

Schlembach, Florian (author), Ehlers, F. (author), Kleinherenbrink, M. (author), Passaro, Marcello (author), Dettmering, Denise (author), Seitz, Florian (author), Slobbe, D.C. (author)

Estimating the three geophysical variables significant wave height (SWH), sea surface height, and wind speed from satellite altimetry continues to be challenging in the coastal zone because the received radar echoes exhibit significant interference from strongly reflective targets such as sandbanks, sheltered bays, ships etc. Fully focused...

journal article 2023

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A noise autocovariance model for SAR altimeter measurements with implications for optimal sampling

Ehlers, F. (author), Slobbe, D.C. (author), Verlaan, M. (author), Kleinherenbrink, M. (author)

Earlier work has empirically demonstrated some advantages of an increased posting rate of Synthetic Aperture Radar (SAR) altimeters beyond the expected ground resolution of about 320 m in Delay-Doppler (unfocused SAR, UFSAR) processing, corresponding to ∼20 Hz sampling. Higher posting rates of 40–80 Hz were shown to prevent spectral aliasing...

journal article 2023

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Wide-Swath Ocean Altimetry Using Multi-Satellite Single-Pass Interferometry

Theodosiou, A. (author), Kleinherenbrink, M. (author), Lopez Dekker, F.J. (author)

Estimating sea surface height using cross-track interferometry (XTI) requires high sensitivity because the ocean surface signal is in the order of 10 cm. In addition, the interferometer requires a temporal delay of a few milliseconds to ensure the coherency of the moving ocean surface. We show that a squinted line of sight (LoS), in...

journal article 2023

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Obukhov Length Estimation From Spaceborne Radars

O’Driscoll, Owen (author), Mouche, Alexis (author), Chapron, Bertrand (author), Kleinherenbrink, M. (author), Lopez Dekker, F.J. (author)

Two air-sea interaction quantification methods are employed on synthetic aperture radar (SAR) scenes containing atmospheric-turbulence signatures. Quantification performance is assessed on Obukhov length L, an atmospheric surface-layer stability metric. The first method correlates spectral energy at specific turbulence-spectrum wavelengths...

journal article 2023