407 results on '"Wouters, Bert"'
Search Results
152. Using contemporary LC theory and technology to improve ion-exchange separations
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Wouters, Bert, Wouters, Sam, Eghbali, Hamed, Eeltink, Sebastiaan, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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Kinetic plot ,Method development ,Column comparison ,Ion chromatography - Abstract
The application of high pressures in ion chromatography (IC) can significantly improve the efficiency and reduce the analysis time. In this work, the kinetic-performance limits of capillary IC columns with inner diameters of 400 µm packed with 4 and 7 µm super macroporous anion-exchange particles were investigated employing a capillary ion-exchange instrument allowing column pressures up to 34MPa. Plate heights below 10 µm could be realized in isocratic mode using capillary columns packed with 4 µm particles. Compared to conventional IC using 7 µm particle-packed columns and pressures up to 20 MPa a 40% improvement in plate number could be achieved when working at the kinetic performance limits at 34 MPa and using columns packed with 4 µm particles. The performance limits were also characterized in gradient mode. Using a linear gradient significant broadening was observed with increasing retention factor. Therefore the use of concave gradients were explored to establish the performance limits at maximum operating pressure. The potential of high-efficiency capillary IC is demonstrated with high-pressure gradient IC separations using coupled columns. In a next step to system miniaturization we are focusing on the development of a portable ion analyzer, composed of different substrate layers, each with their own channel layout and functionality. In a first step, a prototype on-chip microfluidic membrane suppressor has been developed and characterized as a stand-alone module and its capabilities and limitations will be discussed.
- Published
- 2013
153. On the recent contribution of the Greenland ice sheet to sea level change
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van den Broeke, Michiel R., primary, Enderlin, Ellyn M., additional, Howat, Ian M., additional, Kuipers Munneke, Peter, additional, Noël, Brice P. Y., additional, van de Berg, Willem Jan, additional, van Meijgaard, Erik, additional, and Wouters, Bert, additional
- Published
- 2016
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154. Geodetic measurements reveal similarities between post–Last Glacial Maximum and present-day mass loss from the Greenland ice sheet
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Khan, Shfaqat A., primary, Sasgen, Ingo, additional, Bevis, Michael, additional, van Dam, Tonie, additional, Bamber, Jonathan L., additional, Wahr, John, additional, Willis, Michael, additional, Kjær, Kurt H., additional, Wouters, Bert, additional, Helm, Veit, additional, Csatho, Beata, additional, Fleming, Kevin, additional, Bjørk, Anders A., additional, Aschwanden, Andy, additional, Knudsen, Per, additional, and Munneke, Peter Kuipers, additional
- Published
- 2016
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155. On the recent contribution of the Greenland ice sheet to sea level change
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van den Broeke, Michiel, primary, Enderlin, Ellyn, additional, Howat, Ian, additional, Kuipers Munneke, Peter, additional, Noël, Brice, additional, van de Berg, Willem Jan, additional, van Meijgaard, Erik, additional, and Wouters, Bert, additional
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- 2016
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156. Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ
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Muresan, Ioana S., primary, Khan, Shfaqat A., additional, Aschwanden, Andy, additional, Khroulev, Constantine, additional, Van Dam, Tonie, additional, Bamber, Jonathan, additional, van den Broeke, Michiel R., additional, Wouters, Bert, additional, Kuipers Munneke, Peter, additional, and Kjær, Kurt H., additional
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- 2016
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157. POSTER: Characterization of polymer monolithic stationary phases using differential scanning calorimetric techniques
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Wouters, Sam, Wouters, Bert, Vaast, Axel, Van Assche, Guy, Eeltink, Sebastiaan, Physical Chemistry and Polymer Science, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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Stationary phases ,cross-link density ,HPLC ,phase separation ,Porous monoliths - Abstract
Thermal analysis and SEM were employed to gain insights in the different stages of morphology development and the thermal properties of polymer-monolithic stationary phases. The studied system was a thermally initiated free-radical copolymerization reaction at 70C of styrene and divinylbenzene in the presence of tetrahydrofuran and 1-decanol. The key events in the early stages of morphology development are initiation, chain growth, branching, and cyclization, leading to microgel particles. Interparticle reactions through pendant vinyl groups lead to the formation of microgel clusters. The rapid increase in molecular weight and cross-link density of the microgel clusters causes a reaction-induced phase separation, and the formation of a macroscopic network of interconnected globules was observed (macrogelation) at around 45 min. After 3 h or 65% conversion, a space-filling macroporous monolithic network was observed. Afterwards, mainly growth of existing globules takes place, reducing themacropore size. The porogen ratio affects the timing of the reactioninduced phase separation, strongly influencing the morphology of the polymer material. The use of a mixture of divinylbenzene isomers yielded a monolithic material that is less cross-linked at the surface compared to the central part of the polymer backbone due to copolymerization-composition drift. The less cross-linked outer layer starts devitrifying at 100C.
- Published
- 2013
158. The quest for ultra-high peak capacities - spacial three-dimensional chromatography
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Wouters, Bert, De Vos, Jelle, Vaast, Axel, Eeltink, Sebastiaan, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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xx - Abstract
xx
- Published
- 2013
159. CO2 laser cordectomy for bilateral vocal-cord paralysis
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Holm, Adriaan F., Wouters, Bert, and Van Overbeek, Jos J. M.
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- 1989
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160. Visualization procedures for proteins on flat-bed monoliths designed for spatial chromatography and subsequent analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
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Aarnoutse, B., Wouters, Bert, Visser, A, Stassen, Catherine, Devreese, B., Schoenmakers, P.j., Eeltink, Sebastiaan, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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xx - Abstract
xx
- Published
- 2013
161. Towards iso-electric focussing of proteins on a chip for potential use in multi-dimensional separations
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Vonk, R. J., Pirok, Bob, Wouters, Bert, Ariese, F., Eeltink, Sebastiaan, Kok, W.th., Schoenmakers, P.j., Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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cyclic olefin copolymer ,iso-electric focussing - Published
- 2013
162. Irreversible mass loss of Canadian Arctic Archipelago glaciers
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Lenaerts, J.T.M., van Angelen, J.H., van den Broeke, M.R., Gardner, A.S., Wouters, Bert, van Meijgaard, E., Marine and Atmospheric Research, Sub Dynamics Meteorology, Marine and Atmospheric Research, and Sub Dynamics Meteorology
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Glacier ice accumulation ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Global warming ,0207 environmental engineering ,Tidewater glacier cycle ,Glacier ,02 engineering and technology ,Snow ,01 natural sciences ,Glacier mass balance ,Geophysics ,Arctic ,13. Climate action ,Climatology ,General Earth and Planetary Sciences ,020701 environmental engineering ,Meltwater ,Geology ,0105 earth and related environmental sciences - Abstract
The Canadian Arctic Archipelago (CAA) contains the largest volume of glacier ice on Earth outside of Antarctica and Greenland. In the absence of significant calving, CAA glacier mass balance is governed by the difference between surface snow accumulation and meltwater runoff—surface mass balance. Here we use a coupled atmosphere/snow model to simulate present-day and 21st century CAA glacier surface mass balance. Through comparison with Gravity Recovery and Climate Experiment mass anomalies and in situ observations, we show that the model is capable of representing present-day CAA glacier mass loss, as well as the dynamics of the seasonal snow cover on the CAA tundra. Next, we force this model until 2100 with a moderate climate warming scenario (AR5 RCP4.5). We show that enhanced meltwater runoff from CAA glaciers is not sufficiently compensated by increased snowfall. Extrapolation of these results toward an AR5 multimodel ensemble results in sustained 21st century CAA glacier mass loss in the vast majority (>99%) of the ~7000 temperature realizations.
- Published
- 2013
163. Design of microfluidic devices for spatial two-dimensional LC separations
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Wouters, Bert, De Vos, Jelle, Desmet, Gert, Schoenmakers, P.j., Eeltink, Sebastiaan, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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xx - Abstract
xx
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- 2013
164. Design of microfluidic devices for spatial multi-dimensional LC separations
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Wouters, Bert, De Vos, Jelle, Jespers, Sander, Desmet, Gert, Schoenmakers, P.j., Eeltink, Sebastiaan, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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flow distributor ,spatial chromatography ,Monolith - Abstract
A polymer-based microfluidic device has been designed and constructed for comprehensive spatial two-dimensional chromatography, with each peak being characterized by its coordinates in the plane. The device manufactured from cyclic olefin copolymer (COC) features a first-dimension (1D) separation channel and 21 parallel second-dimension (2D) separation channels orientated perpendicular to the 1D channel. Compartmentalization of 1D and 2D flow by a physical barrier allowed for a preferential mobile phase flow path mainly restricted to the 1D separation channel, with a minimal dispersion into the 2D separation channels. After a 1D separation was halted, a radially-interconnected flow distributor of diamond-shaped pillars with diverging side-walls introduced the mobile phase for the 2D separation, allowing eluent inside the 1D channel to be fractionated and simultaneously injected into the 2D channels. A hydrophobic methacrylate-based monolithic stationary phase was polymerized in-situ in desired locations via aUV-initiated polymerization reaction employing a photo mask.
- Published
- 2013
165. Parameters affecting the separation of intact proteins in gradienst-elution reversed-phase chromatography using poly(stryrene-co-divinylbenzene) monolithic capillary columns
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Detobel, Frederik, Broeckhoven, Ken, Wellens, Joke, Wouters, Bert, Remco, Swart, Ursem, Mario, Desmet, Gert, Eeltink, Sebastiaan, Science, Elsevier, Chemical Engineering and Industrial Chemistry, and Chemical Engineering and Separation Science
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Chromatography - Abstract
Parameters affecting the separation of intact proteins in gradient-elution reversed-phase chromatography using poly(styrene-co-divinylbenzene) monolithic capillary columns
- Published
- 2010
166. Design of a microfluidic device for comprehensive spatial two-dimensional liquid chromatography
- Author
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Wouters, Bert, primary, De Vos, Jelle, additional, Desmet, Gert, additional, Terryn, Herman, additional, Schoenmakers, Peter J., additional, and Eeltink, Sebastiaan, additional
- Published
- 2015
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167. Towards ultra-high peak capacities and peak-production rates using spatial three-dimensional liquid chromatography
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Wouters, Bert, primary, Davydova, Ekaterina, additional, Wouters, Sam, additional, Vivo-Truyols, Gabriel, additional, Schoenmakers, Peter J., additional, and Eeltink, Sebastiaan, additional
- Published
- 2015
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168. Partitioning recent Greenland mass loss
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van den Broeke, M.R., Bamber, Jonathan L., Ettema, J., Rignot, Eric, Schrama, Ernst, van de Berg, W.J., Velicogna, I., Wouters, Bert, Marine and Atmospheric Research, Sub Dynamics Meteorology, and Dep Natuurkunde
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International (English) - Abstract
Mass budget calculations, validated with satellite gravity observations [from the Gravity Recovery and Climate Experiment (GRACE) satellites], enable us to quantify the individual components of recent Greenland mass loss. The total 2000–2008 mass loss of ~1500 gigatons, equivalent to 0.46 millimeters per year of global sea level rise, is equally split between surface processes (runoff and precipitation) and ice dynamics. Without the moderating effects of increased snowfall and refreezing, post-1996 Greenland ice sheet mass losses would have been 100% higher. Since 2006, high summer melt rates have increased Greenland ice sheet mass loss to 273 gigatons per year (0.75 millimeters per year of equivalent sea level rise). The seasonal cycle in surface mass balance fully accounts for detrended GRACE mass variations, confirming insignificant subannual variation in ice sheet discharge
- Published
- 2009
169. A mascon approach to assess ice sheet and glacier mass balances and their uncertainties from GRACE data
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Schrama, Ernst J. O., primary, Wouters, Bert, additional, and Rietbroek, Roelof, additional
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- 2014
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170. Monitoring the morphology development of polymer-monolithic stationary phases by thermal analysis
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Wouters, Sam, primary, Wouters, Bert, additional, Vaast, Axel, additional, Terryn, Herman, additional, Van Assche, Guy, additional, and Eeltink, Sebastiaan, additional
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- 2013
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171. Real-time multi-model decadal climate predictions
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Smith, Doug M., primary, Scaife, Adam A., additional, Boer, George J., additional, Caian, Mihaela, additional, Doblas-Reyes, Francisco J., additional, Guemas, Virginie, additional, Hawkins, Ed, additional, Hazeleger, Wilco, additional, Hermanson, Leon, additional, Ho, Chun Kit, additional, Ishii, Masayoshi, additional, Kharin, Viatcheslav, additional, Kimoto, Masahide, additional, Kirtman, Ben, additional, Lean, Judith, additional, Matei, Daniela, additional, Merryfield, William J., additional, Müller, Wolfgang A., additional, Pohlmann, Holger, additional, Rosati, Anthony, additional, Wouters, Bert, additional, and Wyser, Klaus, additional
- Published
- 2012
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172. Capillary Ion Chromatography at High Pressure and Temperature
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Wouters, Bert, primary, Bruggink, Cees, additional, Desmet, Gert, additional, Agroskin, Yury, additional, Pohl, Christopher A., additional, and Eeltink, Sebastiaan, additional
- Published
- 2012
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173. Timing and origin of recent regional ice-mass loss in Greenland
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Sasgen, Ingo, primary, van den Broeke, Michiel, additional, Bamber, Jonathan L., additional, Rignot, Eric, additional, Sørensen, Louise Sandberg, additional, Wouters, Bert, additional, Martinec, Zdeněk, additional, Velicogna, Isabella, additional, and Simonsen, Sebastian B., additional
- Published
- 2012
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174. Recent mass changes of glaciers in the Russian High Arctic
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Moholdt, Geir, primary, Wouters, Bert, additional, and Gardner, Alex S., additional
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- 2012
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175. Revisiting Greenland ice sheet mass loss observed by GRACE
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Schrama, Ernst J. O., primary and Wouters, Bert, additional
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- 2011
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176. Sea-level fingerprint of continental water and ice mass change from GRACE
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Riva, Riccardo E. M., primary, Bamber, Jonathan L., additional, Lavallée, David A., additional, and Wouters, Bert, additional
- Published
- 2010
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177. Parameters affecting the separation of intact proteins in gradient-elution reversed-phase chromatography using poly(styrene-co-divinylbenzene) monolithic capillary columns
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Detobel, Frederik, primary, Broeckhoven, Ken, additional, Wellens, Joke, additional, Wouters, Bert, additional, Swart, Remco, additional, Ursem, Mario, additional, Desmet, Gert, additional, and Eeltink, Sebastiaan, additional
- Published
- 2010
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178. Signal and noise in Gravity Recovery and Climate Experiment (GRACE) observed surface mass variations
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Schrama, Ernst J. O., primary, Wouters, Bert, additional, and Lavallée, David A., additional
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- 2007
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179. Impact of Initial Conditions versus External Forcing in Decadal Climate Predictions: A Sensitivity Experiment.
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CORTI, SUSANNA, PALMER, TIM, BALMASEDA, MAGDALENA, WEISHEIMER, ANTJE, DRIJFHOUT, SYBREN, DUNSTONE, NICK, HAZELEGER, WILCO, KRÖGER, JÜRGEN, POHLMANN, HOLGER, SMITH, DOUG, VON STORCH, JIN-SONG, and WOUTERS, BERT
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CLIMATE change forecasts ,CLIMATE change ,SENSITIVITY analysis ,OCEAN temperature ,MERIDIONAL overturning circulation ,LOGICAL prediction - Abstract
The impact of initial conditions relative to external forcings in decadal integrations from an ensemble of state-of-the-art prediction models has been assessed using specifically designed sensitivity experiments (SWAP experiments). They consist of two sets of 10-yr-long ensemble hindcasts for two initial dates in 1965 and 1995 using either the external forcings from the "correct" decades or swapping the forcings between the two decades. By comparing the two sets of integrations, the impact of external forcing versus initial conditions on the predictability over multiannual time scales was estimated as the function of lead time of the hindcast. It was found that over time scales longer than about 1 yr, the predictability of sea surface temperatures (SSTs) on a global scale arises mainly from the external forcing. However, the correct initialization has a longer impact on SST predictability over specific regions such as the North Atlantic, the northwestern Pacific, and the Southern Ocean. The impact of initialization is even longer and extends to wider regions when below-surface ocean variables are considered. For the western and eastern tropical Atlantic, the impact of initialization for the 700-m heat content (HTC700) extends to as much as 9 years for some of the models considered. In all models the impact of initial conditions on the predictability of the Atlantic meridional overturning circulation (AMOC) is dominant for the first 5 years. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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180. Using contemporary liquid chromatography theory and technology to improve capillary gradient ion-exchange separations.
- Author
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Wouters, Bert, Broeckhoven, Ken, Wouters, Sam, Bruggink, Cees, Agroskin, Yury, Pohl, Christopher A., and Eeltink, Sebastiaan
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CAPILLARY columns , *LIQUID chromatography , *ION exchange (Chemistry) , *ANIONS , *SEPARATION (Technology) - Abstract
The gradient-performance limits of capillary ion chromatography have been assessed at maximum system pressure (34.5 MPa) using capillary columns packed with 4.1 μm macroporous anion-exchange particles coated with 65 nm positively-charged nanobeads. In analogy to the van-Deemter curve, the gradient performance was assessed applying different flow rates, while decreasing the gradient time inversely proportional to the increase in flow rate in order to maintain the same retention properties. The gradient kinetic-performance limits were determined at maximum system pressure, applying t G / t 0 = 5, 10, and 20. In addition, the effect of retention on peak width was assessed in gradient mode for mono-, di-, and trivalent inorganic anions. The peak width of late-eluting ions can be significantly reduced by using concave gradient, resulting in better detection sensitivity. A signal enhancement factor of 8 was measured for a late-eluting ion when applying a concave instead of a linear gradient. For the analysis of a complex anion mixture, a coupled column with a total length of 1.05 m was operated at the kinetic-performance limit applying a linear 250 min gradient ( t G / t 0 = 10). The peak capacity varied between 200 and 380 depending on analyte retention, and hence on charge and size of the ion. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
181. A multi-model comparison of Atlantic multidecadal variability.
- Author
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Ba, Jin, Keenlyside, Noel, Latif, Mojib, Park, Wonsun, Ding, Hui, Lohmann, Katja, Mignot, Juliette, Menary, Matthew, Otterå, Odd, Wouters, Bert, Salas y Melia, David, Oka, Akira, Bellucci, Alessio, and Volodin, Evgeny
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GENERAL circulation model ,OCEAN temperature ,CLIMATE change ,CLIMATOLOGY ,COMPARATIVE studies - Abstract
A multi-model analysis of Atlantic multidecadal variability is performed with the following aims: to investigate the similarities to observations; to assess the strength and relative importance of the different elements of the mechanism proposed by Delworth et al. (J Clim 6:1993-2011, 1993) (hereafter D93) among coupled general circulation models (CGCMs); and to relate model differences to mean systematic error. The analysis is performed with long control simulations from ten CGCMs, with lengths ranging between 500 and 3600 years. In most models the variations of sea surface temperature (SST) averaged over North Atlantic show considerable power on multidecadal time scales, but with different periodicity. The SST variations are largest in the mid-latitude region, consistent with the short instrumental record. Despite large differences in model configurations, we find quite some consistency among the models in terms of processes. In eight of the ten models the mid-latitude SST variations are significantly correlated with fluctuations in the Atlantic meridional overturning circulation (AMOC), suggesting a link to northward heat transport changes. Consistent with this link, the three models with the weakest AMOC have the largest cold SST bias in the North Atlantic. There is no linear relationship on decadal timescales between AMOC and North Atlantic Oscillation in the models. Analysis of the key elements of the D93 mechanisms revealed the following: Most models present strong evidence that high-latitude winter mixing precede AMOC changes. However, the regions of wintertime convection differ among models. In most models salinity-induced density anomalies in the convective region tend to lead AMOC, while temperature-induced density anomalies lead AMOC only in one model. However, analysis shows that salinity may play an overly important role in most models, because of cold temperature biases in their relevant convective regions. In most models subpolar gyre variations tend to lead AMOC changes, and this relation is strong in more than half of the models. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
182. Theaflavin-enriched green tea extract lowers low-density lipoprotein cholesterol
- Author
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Maron, David J., primary, Lu, Guo Ping, additional, Sheng, Cai Nai, additional, Wu, Zhong Gui, additional, Li, Yue Hua, additional, Chen, Hui, additional, Zhu, Jian Qiu, additional, Jin, Xue Juan, additional, Wouters, Bert C., additional, and Zhao, Jim, additional
- Published
- 2003
- Full Text
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183. Design and performance evaluation of a microfluidic ion-suppression module for anion-exchange chromatography.
- Author
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Wouters, Sam, Wouters, Bert, Jespers, Sander, Desmet, Gert, Eghbali, Hamed, Bruggink, Cees, and Eeltink, Sebastiaan
- Subjects
- *
PERFORMANCE evaluation , *MICROFLUIDICS , *ION exchange resins , *ACID-base chemistry , *SEPARATION (Technology) , *MICROREACTORS - Abstract
A microfluidic membrane suppressor has been constructed to suppress ions of alkaline mobile-phases via an acid-base reaction across a sulfonated poly(tetrafluoroethylene)-based membrane and was evaluated for anion-exchange separations using conductivity detection. The membrane was clamped between two chip substrates, accommodating rectangular microchannels for the eluent and regenerant flow, respectively. Additionally, a clamp-on chip holder has been constructed which allows the alignment and stacking of different chip modules. The response and efficacy of the microfluidic chip suppressor was assessed for a wide range of eluent (KOH) concentrations, using 127 and 183µm thick membranes, while optimizing the flow rate and concentration of the regenerant solution (H2SO4). The optimal operating eluent flow rate was determined at 5µL/min, corresponding to the optimal van-Deemter flow velocity of commercially-available column technology, i.e. a 0.4mm i.d.×250mm long column packed with 7.5µm anion-exchange particles. When equilibrated at 10mM KOH, a 99% decrease in conductivity signal could be obtained within 5min when applying 10mM H2SO4 regenerant at 75µL/min. A background signal as low as 1.2µS/cm was obtained, which equals the performance of a commercially-available electrolytic hollow-fiber suppressor. When increasing the temperature of the membrane suppressor from 15 to 20°C, ion suppression was significantly improved allowing the application of 75mM KOH. The applicability of the chip suppressor has been demonstrated with an isocratic baseline separation of a mixture of seven inorganic ions, yielding plate numbers between 5300 and 10,600 and with a gradient separation of a complex ion mixture. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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184. Greenland Surface Mass Balance as Simulated by the Community Earth System Model. Part I: Model Evaluation and 1850-2005 Results.
- Author
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Vizcaíno, Miren, Lipscomb, William H., Sacks, William J., van Angelen, Jan H., Wouters, Bert, and van den Broeke, Michiel R.
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MASS budget (Geophysics) ,ICE sheets ,CLIMATE research ,ALBEDO - Abstract
The modeling of the surface mass balance (SMB) of the Greenland Ice Sheet (GIS) requires high-resolution models in order to capture the observed large gradients in the steep marginal areas. Until now, global climate models have not been considered suitable to model ice sheet SMB owing to model biases and insufficient resolution. This study analyzes the GIS SMB simulated for the period 1850-2005 by the Community Earth System Model (CESM), which includes a new ice sheet component with multiple elevation classes for SMB calculations. The model is evaluated against observational data and output from the regional model Regional Atmospheric Climate Model version 2 (RACMO2). Because of a lack of major climate biases, a sophisticated calculation of snow processes (including surface albedo evolution) and an adequate downscaling technique, CESM is able to realistically simulate GIS surface climate and SMB. CESM SMB agrees reasonably well with in situ data from 475 locations ( r = 0.80) and output from RACMO2 ( r = 0.79). The simulated mean SMB for 1960-2005 is 359 ± 120 Gt yr
−1 in the range of estimates from regional climate models. The simulated seasonal mass variability is comparable with mass observations from the Gravity Recovery and Climate Experiment (GRACE), with synchronous annual maximum (May) and minimum (August-September) and similar amplitudes of the seasonal cycle. CESM is able to simulate the bands of precipitation maxima along the southeast and northwest margins, but absolute precipitation rates are underestimated along the southeastern margin and overestimated in the high interior. The model correctly simulates the major ablation areas. Total refreezing represents 35% of the available liquid water (the sum of rain and melt). [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
185. Visualization procedures for proteins and peptides on flat-bed monoliths and their effects on matrix-assisted laser-desorption/ionization time-of-flight mass spectrometric detection
- Author
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Wouters, Bert, Vanhoutte, Dominique J.D., Aarnoutse, Petra, Visser, Adriaan, Stassen, Catherine, Devreese, Bart, Kok, Wim Th., Schoenmakers, Peter J., and Eeltink, Sebastiaan
- Subjects
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PEPTIDES , *MONOLITHIC reactors , *MATRIX-assisted laser desorption-ionization , *TIME-of-flight mass spectrometry , *DETECTORS , *SURFACE chemistry , *CONDENSATION reactions - Abstract
Abstract: The present study concerns the application of visualization methods, i.e. coomassie-brilliant-blue-R staining (CBB-R), silver-nitrate staining, and fluorescamine labeling, and subsequent MALDI-MS analysis of intact proteins and peptides on the surface of flat-bed monoliths, intended for spatial two-dimensional chromatographic separations. The use of 100-μm thick macroporous poly(butyl methacrylate-co-ethylene dimethacrylate) flat-bed monoliths renders a fixation step obsolete, so that CBB-R and silver-nitrate staining and destaining could be achieved in 10–15min as opposed to up to 24h, as is typical on 2D-PAGE gels. The detection limits remained comparable. The compatibility of the monolithic layer with subsequent MALDI-MS analysis of individual proteins and peptide spots was investigated with regards to mass accuracy, mass precision, resolution, and signal intensity. When comparing results from MALDI-MS analysis of proteins and peptides on a flat-bed monolith to results obtained directly on stainless-steel target plates, significant losses in mass precision, signal intensity, and an increased variation in resolution were observed. In addition, a loss in signal intensity up to two orders of magnitude was observed when using monolithic layers. After CCB-R and silver-nitrate staining and destaining to disrupt the protein–dye complexes no MALDI spectra with significant S/N ratios could be achieved. After fluorescamine labeling heterogeneous signals were observed, which resulted from a distribution in the number of fluorescence-labeled lysine groups and from the presence of labeled derivatives that had undergone condensation reactions. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
186. Decadal prediction skill in a multi-model ensemble.
- Author
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Oldenborgh, Geert, Doblas-Reyes, Francisco, Wouters, Bert, and Hazeleger, Wilco
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ATMOSPHERIC models ,PREDICTION theory ,CLIMATE change ,BOUNDARY value problems ,GREENHOUSE gases ,STRATOSPHERIC aerosols ,TROPOSPHERIC aerosols ,OCEAN-atmosphere interaction ,OCEAN temperature ,WEATHER forecasting - Abstract
Decadal climate predictions may have skill due to predictable components in boundary conditions (mainly greenhouse gas concentrations but also tropospheric and stratospheric aerosol distributions) and initial conditions (mainly the ocean state). We investigate the skill of temperature and precipitation hindcasts from a multi-model ensemble of four climate forecast systems based on coupled ocean-atmosphere models. Regional variations in skill with and without trend are compared with similarly analysed uninitialised experiments to separate the trend due to monotonically increasing forcings from fluctuations around the trend due to the ocean initial state and aerosol forcings. In temperature most of the skill in both multi-model ensembles comes from the externally forced trends. The rise of the global mean temperature is represented well in the initialised hindcasts, but variations around the trend show little skill beyond the first year due to the absence of volcanic aerosols in the hindcasts and the unpredictability of ENSO. The models have non-trivial skill in hindcasts of North Atlantic sea surface temperature beyond the trend. This skill is highest in the northern North Atlantic in initialised experiments and in the subtropical North Atlantic in uninitialised simulations. A similar result is found in the Pacific Ocean, although the signal is less clear. The uninitialised simulations have good skill beyond the trend in the western North Pacific. The initialised experiments show some skill in the decadal ENSO region in the eastern Pacific, in agreement with previous studies. However, the results in this study are not statistically significant ( p ≈ 0.1) by themselves. The initialised models also show some skill in forecasting 4-year mean Sahel rainfall at lead times of 1 and 5 years, in agreement with the observed teleconnection from the Atlantic Ocean. Again, the skill is not statistically significant ( p ≈ 0.2). Furthermore, uninitialised simulations that include volcanic aerosols have similar skill. It is therefore still an open question whether initialisation improves predictions of Sahel rainfall. We conclude that the main source of skill in forecasting temperature is the trend forced by rising greenhouse gas concentrations. The ocean initial state contributes to skill in some regions, but variations in boundary forcings such as aerosols are as important in decadal forecasting. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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187. The Effect of the 18.6-Year Lunar Nodal Cycle on Regional Sea-Level Rise Estimates.
- Author
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Baart, Fedor, Van Gelder, Pieter H. A. J. M., De Ronde, John, Van Koningsveld, Mark, and Wouters, Bert
- Subjects
ABSOLUTE sea level change ,ESTIMATES ,COASTAL zone management ,LAND subsidence ,TIDES ,LUNAR orbit ,MOON - Abstract
Sea-level rise rates have become important drivers for policy makers dealing with the long-term protection of coastal populations. Scenario studies suggest that an acceleration in sea-level rise is imminent. The anticipated acceleration is hard to detect because of spatial and temporal variability, which consequently, have become important research topics. A known decadal-scale variation is the 18.6-year nodal cycle. Here, we show how failing to account for the nodal cycle resulted in an overestimation of Dutch sea-level rise. The nodal cycle is present across the globe with a varying phase and a median amplitude of 2.2 cm. Accounting for the nodal cycle increases the probability of detecting acceleration in the rate of sea-level rise. In an analysis of the Dutch coast, however, still no significant acceleration was found. The nodal cycle causes sea level to drop or to rise at an increased rate; therefore, accounting for it is crucial to accurately estimate regional sea-level rise. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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188. High-resolution separations of protein isoforms with liquid chromatography time-of-flight mass spectrometry using polymer monolithic capillary columns
- Author
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Eeltink, Sebastiaan, Wouters, Bert, Desmet, Gert, Ursem, Mario, Blinco, David, Kemp, Glenwyn D., and Treumann, Achim
- Subjects
- *
HIGH performance liquid chromatography , *PROTEIN fractionation , *TIME-of-flight mass spectrometry , *AMINO acid sequence , *SENSITIVITY analysis , *PHASE equilibrium , *OXIDATION , *MOLECULAR structure - Abstract
Abstract: The separation of intact proteins, including protein isoforms arising from various amino-acid modifications, employing a poly(styrene-co-divinylbenzene) monolithic capillary column in high-performance liquid chromatography coupled on-line to a time-of-flight mass spectrometer (MS) is described. Using a 250mm×0.2mm monolithic capillary column high-sensitivity separations yielding peak capacities of >600 were achieved with a 2h linear gradient and formic acid added in the mobile phase as ion-pairing agent. The combination of high-resolution chromatography with high-accuracy MS allowed to distinguish protein isoforms that differ only in their oxidation and biotinylation state allowing the separation between structural isoforms. Finally, the potential to separate proteins isoforms due to glycosylation is discussed. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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189. GPS‐Observed Elastic Deformation Due to Surface Mass Balance Variability in the Southern Antarctic Peninsula
- Author
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Koulali, Achraf, Whitehouse, Pippa L., Clarke, Peter J., Broeke, Michiel R., Nield, Grace A., King, Matt A., Bentley, Michael J., Wouters, Bert, and Wilson, Terry
- Abstract
In Antarctica, Global Positioning System (GPS) vertical time series exhibit non‐linear signals over a wide range of temporal scales. To explain these non‐linearities, a number of hypotheses have been proposed, among them the short‐term rapid solid Earth response to contemporaneous ice mass change. Here we use GPS vertical time series to reveal the solid Earth response to variations in surface mass balance (SMB) in the Southern Antarctic Peninsula (SAP). At four locations in the SAP we show that interannual variations of SMB anomalies cause measurable elastic deformation. We use regional climate model SMB products to calculate the induced displacement assuming a perfectly elastic Earth. Our results show a reduction of the misfit when fitting a linear trend to GPS time series corrected for the elastic response to SMB variations. Our results imply that, for a better understanding of the glacial isostatic adjustment signal in Antarctica, SMB variability must be considered. The Global Positioning System (GPS) allows us to measure the changing shape of the Earth's surface with high accuracy. These changes reflect multiple processes operating both within the Earth and at the surface. Using continuously recording GPS instruments in the Antarctic Peninsula, we study the response of the solid Earth to seasonal and annual variations in snow and ice accumulation over the past decade. We show that such loading triggers a measurable response that varies between years, complicating efforts to calculate the long‐term Earth response to past ice sheet change. We discuss the importance of our findings for understanding feedbacks between the solid Earth and the Antarctic ice sheet. Global Positioning System time series of vertical deformation in the Southern Antarctic Peninsula show transient signalsModeled elastic deformation due to surface mass balance (SMB) variation can largely explain these signalsConsidering SMB elastic deformation improves estimates of linear vertical velocities Global Positioning System time series of vertical deformation in the Southern Antarctic Peninsula show transient signals Modeled elastic deformation due to surface mass balance (SMB) variation can largely explain these signals Considering SMB elastic deformation improves estimates of linear vertical velocities
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- 2022
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190. Physically‐Informed Super‐Resolution Downscaling of Antarctic Surface Melt.
- Author
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de Roda Husman, Sophie, Hu, Zhongyang, van Tiggelen, Maurice, Dell, Rebecca, Bolibar, Jordi, Lhermitte, Stef, Wouters, Bert, and Munneke, Peter Kuipers
- Subjects
- *
ICE shelves , *AUTOMATIC meteorological stations , *MELTING , *DEEP learning , *REMOTE sensing , *ATMOSPHERIC models - Abstract
Because Antarctic surface melt is mostly driven by local processes, its simulation necessitates high‐resolution regional climate models (RCMs). However, the current horizontal resolution of RCMs (≈25–30 km) is inadequate for capturing small‐scale melt processes. To address this limitation, we present SUPREME (SUPer‐REsolution‐based Melt Estimation over Antarctica), a deep learning method to downscale surface melt to 5.5 km resolution using a physically‐informed super‐resolution model. The physical information integrated into the model originates from observations tied to surface melt, specifically remote sensing‐derived albedo and elevation. These remote sensing data, in addition to a Regional Atmospheric Climate Model (RACMO) run at 27 km resolution, account for the diverse drivers of surface melt across Antarctica, facilitating effective generalization beyond the training region of the Antarctic Peninsula. A comparison of SUPREME with a dynamically downscaled RACMO run at 5.5 km over the Antarctic Peninsula shows high accuracy, with average yearly RMSE and bias of 5.5 mm w.e. yr−1 and 4.5 mm w.e. yr−1, respectively. Validation at five automatic weather stations reveals SUPREME's marked improvement with substantially lower average RMSE (81 mm w.e.) compared to RACMO 27 km (129 mm w.e.). Beyond the training region, SUPREME aligns more closely with remote sensing products associated with surface melt than super‐resolution models lacking physical constraints. While further validation of SUPREME is needed, our study highlights the potential of super‐resolution techniques with physical constraints for high‐resolution surface melt monitoring in Antarctica, providing insights into the impacts of localized melting on processes affecting ice shelf integrity such as hydrofracturing. Plain Language Summary: To improve surface melt monitoring in Antarctica, high‐resolution climate models are essential. Existing models, like the Regional Atmospheric Climate Model (RACMO), do not have a fine enough spatial resolution to capture small‐scale melt processes. To overcome this, we introduce SUPREME (SUPer‐REsolution‐based Melt Estimation over Antarctica), a method that refines surface melt data to a higher resolution of 5.5 km using an advanced super‐resolution model. We enhance this model with physical information derived from observations directly related to surface melt, specifically using albedo and elevation data from remote sensing. By incorporating these observations, along with RACMO data at 27 km resolution, we account for the various triggers of surface melt across Antarctica. SUPREME accurately predicts high‐resolution surface melt beyond the training region of the Antarctic Peninsula, showing promising results compared to existing melt observations. Further validation is needed, but this approach, combining super‐resolution techniques and remote sensing data, holds potential for accurate surface melt monitoring in Antarctica. This may advance our understanding of the impacts of localized features on processes affecting ice shelf integrity such as meltwater‐induced hydrofracturing. Key Points: Our method downscales Antarctic surface melt from a regional climate model, employing a physically‐informed super‐resolution architectureThe super‐resolution model relies on physical information derived from remote sensing data, specifically surface albedo and elevationIncorporating physical information boosts model generalization, enabling accurate high‐resolution surface melt beyond the training region [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
191. The Arctic
- Author
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Andersen, J K, Andreassen, Liss M, Baker, Emily H, Ballinger, Thomas J, Berner, Logan T, Bernhard, Germar H, Bhatt, Uma S, Bjerke, Jarle W, Box, Jason E, Britt, L, Brown, R, Burgess, David, Cappelen, John, Christiansen, Hanne H, Decharme, B, Derksen, C, Drozdov, D S, Epstein, Howard E, Farquharson, L M, Farrell, Sinead L, Fausto, Robert S, Fettweis, Xavier, Fioletov, Vitali E, Forbes, Bruce C, Frost, Gerald V, Gerland, Sebastian, Goetz, Scott J, Grooß, Jens-Uwe, Hanna, Edward, Hanssen-Bauer, Inger, Hendricks, Stefan, Ialongo, Iolanda, Isaksen, K, Johnsen, Bjørn, Kaleschke, L, Kholodov, A L, Kim, Seong-Joong, Kohler, Jack, Labe, Zachary, Ladd, Carol, Lakkala, Kaisa, Lara, Mark J, Loomis Bryant andLuks, Bartlomiej, Luojus, K, Macander, Matthew J, Malkova, G V, Mankoff, Kenneth D, Manney, Gloria L, Marsh, J M, Meier, Walt, Moon, Twila A, Mote, Thomas, Mudryk, L, Mueter, F J, Müller, Rolf, Nyland, K E, O'Neel, Shad, Overland, James E, Perovich, Don, Phoenix, Gareth K, Raynolds, Martha K, Reijmer, C H, Ricker, Robert, Romanovsky, Vladimir E, Schuur, E A G, Sharp, Martin, Shiklomanov, Nikolai I, Smeets, C J P P, Smith, Sharon L, Streletskiy, Dimitri A, Tedesco, Marco, Thoman, Richard L, Thorson, J T, Tian-Kunze, X, Timmermans, Mary-Louise, Tømmervik, Hans, Tschudi, Mark, van As, Dirk, van de Wal, R S W, Walker, Donald A, Walsh, John E, Wang, Muyin, Webster, Melinda, Winton, Øyvind, Wolken, Gabriel J, Wood, K, Wouters, Bert, Zador, S, Richter-Menge, Jacqueline, Druckenmiller, Matthew L, Dep Natuurkunde, Sub Dynamics Meteorology, Proceskunde, Sub Algemeen Marine & Atmospheric Res, Marine and Atmospheric Research, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,Oceanography ,State (polity) ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,media_common.quotation_subject ,Environmental science ,[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology ,[SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology ,ComputingMilieux_MISCELLANEOUS ,media_common ,The arctic - Abstract
International audience
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192. Correlation dispersion as a measure to better estimate uncertainty in remotely sensed glacier displacements.
- Author
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Altena, Bas, Kääb, Andreas, and Wouters, Bert
- Subjects
- *
SURFACE waves (Seismic waves) , *GLACIERS , *DISPLACEMENT (Mechanics) , *NON-uniform flows (Fluid dynamics) , *SHEAR flow , *REMOTE-sensing images ,GLACIER speed - Abstract
In recent years a vast amount of glacier surface velocity data from satellite imagery has emerged based on correlation between repeat images. Thereby, much emphasis has been put on the fast processing of large data volumes and products with complete spatial coverage. The metadata of such measurements are often highly simplified when the measurement precision is lumped into a single number for the whole dataset, although the error budget of image matching is in reality neither isotropic nor constant over the whole velocity field. The spread of the correlation peak of individual image offset measurements is dependent on the image structure and the non-uniform flow of the ice and is used here to extract a proxy for measurement uncertainty. A quantification of estimation error or dispersion for each individual velocity measurement can be important for the inversion of, for instance, rheology, ice thickness and/or bedrock friction. Errors in the velocity data can propagate into derived results in a complex and exaggerating way, making the outcomes very sensitive to velocity noise and outliers. Here, we present a computationally fast method to estimate the matching precision of individual displacement measurements from repeat imaging data, focusing on satellite data. The approach is based upon Gaussian fitting directly on the correlation peak and is formulated as a linear least-squares estimation, making its implementation into current pipelines straightforward. The methodology is demonstrated for Sermeq Kujalleq (Jakobshavn Isbræ), Greenland, a glacier with regions of strong shear flow and with clearly oriented crevasses, and Malaspina Glacier, Alaska. Directionality within an image seems to be the dominant factor influencing the correlation dispersion. In our cases these are crevasses and moraine bands, while a relation to differential flow, such as shear, is less pronounced on the correlation spread. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
193. CO2 laser cordectomy for bilateral vocal-cord paralysis
- Author
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Holm, Adriaan F., Wouters, Bert, and Van Overbeek, Jos J. M.
- Abstract
Bilateral vocal-cord paralysis usually causes dyspnoea with inspiratory stridor. Most patients have a fairly satisfactory voice. The purpose of this paper is to present the results of a series of 24 patients with bilateral vocal-cord paralysis treated by CO
2 laser cordectomy during 1978–86. Breathing improved in 19 patients. In most of the patients, however, the voice worsened. If further surgery is necessary this can easily be performed. In appropriate patients the CO2 laser is an ideal surgical tool for the performance of a cordectomy in patients with bilateral vocal-cord paralysis.- Published
- 1989
- Full Text
- View/download PDF
194. Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment.
- Author
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Lhermitte, Stef, Sun, Sainan, Shuman, Christopher, Wouters, Bert, Pattyn, Frank, Wuite, Jan, Berthier, Etienne, and Nagler, Thomas
- Published
- 2019
195. Global sea-level budget 1993-present
- Author
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Cazenave, Anny, Meyssignac, Benoit, Ablain, Michael, Balmaseda, Magdalena, Bamber, Jonathan, Barletta, Valentina, Beckley, Brian, Benveniste, Jerome, Berthier, Etienne, Blazquez, Alejandro, Boyer, Tim, Cáceres, Denise, Chambers, Don, Champollion, Nicolas, Chao, Ben, Chen, Jianli, Cheng, Lijing, Church, John A., Chuter, Stephen, Cogley, J. Graham, Dangendorf, Soenke, Desbruyères, Damien, Döll, Petra, Domingues, Catia, Falk, Ulrike, Famiglietti, James, Fenoglio-Marc, Luciana, Forsberg, Rene, Galassi, Gaia, Gardner, Alex, Groh, Andreas, Hamlington, Benjamin, Hogg, Anna, Horwath, Martin, Humphrey, Vincent, Husson, Laurent, Ishii, Masayoshi, Jäggi, Adrian, Jevrejeva, Svetlana, Johnson, Gregory C., Kolodziejczyk, Nicolas, Kusche, Jürgen, Lambeck, Kurt, Landerer, Felix, Leclercq, Paul W., Legresy, Benoit, Leuliette, Eric, Llovel, William, Longuevergne, Laurent, Loomis, Bryant D., Luthcke, Scott B., Marcos, Marta, Marzeion, Ben, Merchant, Chris, Merrifield, Mark, Milne, Glenn, Mitchum, Gary, Mohajerani, Yara, Monier, Maeva, Monselesan, Didier, Nerem, Steve, Palanisamy, Hindumathi, Paul, Frank, Perez, Begoña, Piecuch, Christopher G., Ponte, Rui M., Purkey, Sarah G., Reager, John T., Rietbroek, Roelof, Rignot, Eric, Riva, Riccardo, Roemmich, Dean, Sørensen, Louise S., Sasgen, Ingo, Schrama, E.J.O., Seneviratne, Sonia I., Shum, C.K., Spada, Giorgio, Stammer, Detlef, Velicogna, Isabella, von Schuckmann, Karina, Wada, Yoshihide, Wang, Yiguo, Watson, Christopher, Wiese, David, Wijffels, Susan, Westaway, Richard, Woppelmann, Guy, and Wouters, Bert
- Subjects
13. Climate action ,14. Life underwater - Abstract
Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g., acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled "Regional Sea Level and Coastal Impacts", an international effort involving the sea-level community worldwide has been recently initiated with the objective of assessing the various datasets used to estimate components of the sea-level budget during the altimetry era (1993 to present). These datasets are based on the combination of a broad range of space-based and in situ observations, model estimates, and algorithms. Evaluating their quality, quantifying uncertainties and identifying sources of discrepancies between component estimates is extremely useful for various applications in climate research. This effort involves several tens of scientists from about 50 research teams/institutions worldwide (www.wcrp-climate.org/grand-challenges/gc-sea-level, last access: 22 August 2018). The results presented in this paper are a synthesis of the first assessment performed during 2017–2018. We present estimates of the altimetry-based global mean sea level (average rate of 3.1±0.3mmyr−1 and acceleration of 0.1mmyr−2 over 1993–present), as well as of the different components of the sea-level budget (http://doi.org/10.17882/54854, last access: 22 August 2018). We further examine closure of the sea-level budget, comparing the observed global mean sea level with the sum of components. Ocean thermal expansion, glaciers, Greenland and Antarctica contribute 42%, 21%, 15% and 8% to the global mean sea level over the 1993–present period. We also study the sea-level budget over 2005–present, using GRACE-based ocean mass estimates instead of the sum of individual mass components. Our results demonstrate that the global mean sea level can be closed to within 0.3mmyr−1 (1σ). Substantial uncertainty remains for the land water storage component, as shown when examining individual mass contributions to sea level., Earth System Science Data, 10 (3), ISSN:1866-3516, ISSN:1866-3508
196. The land ice contribution to sea level during the satellite era
- Author
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Bamber, Jonathan, Westaway, Richard, Marzeion, Ben, and Wouters, Bert
- Subjects
13. Climate action ,Glaciology ,Physical Sciences and Mathematics ,Earth Sciences ,14. Life underwater - Abstract
Since 1992, there has been a revolution in our ability to quantify the land ice contribution to SLR using a variety of satellite missions and technologies. Each mission has provided unique, but sometimes conflicting, insights into the mass trends of land ice. Over the last decade, over fifty estimates of land ice trends have been published, providing a confusing and often inconsistent picture. The IPCC Fifth Assessment Report (AR5) attempted to synthesise estimates published up to early 2013. Since then, considerable advances have been made in understanding the origin of the inconsistencies, reducing uncertainties in estimates and extending time series. We assess and synthesise results published, primarily, since the AR5, to produce a consistent estimate of land ice mass trends during the satellite era (1992 to 2016). We combine observations from multiple missions and approaches including sea level budget analyses. Our resulting synthesis is both consistent and rigorous, drawing on i) the published literature, ii) expert assessment of that literature, and iii) a new analysis of Arctic glacier and ice cap trends combined with statistical modelling. We present annual and pentad (five-year mean) time series for the East, West Antarctic and Greenland Ice Sheets and glaciers separately and combined. When averaged over pentads, covering the entire period considered, we obtain a monotonic trend in mass contribution to the oceans, increasing from 0.31±0.35 mm of sea level equivalent for 1992-1996 to 1.85±0.13 for 2012-2016. Our integrated land ice trend is lower than many estimates of GRACE-derived ocean mass change for the same periods. This is due, in part, to a smaller estimate for glacier and ice cap mass trends compared to previous assessments. We discuss this, and other likely reasons, for the difference between GRACE ocean mass and land ice trends.
197. Dextrocardia?
- Author
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Mannes, Gregor P.M., primary, Jagt, Eric J. van der, additional, Wouters, Bert, additional, and Postmus, Pieter E., additional
- Published
- 1989
- Full Text
- View/download PDF
198. JOINT INVERSION ESTIMATE OF REGIONAL GLACIAL ISOSTATIC ADJUSTMENT IN ANTARCTICA CONSIDERING A LATERAL VARYING EARTH STRUCTURE (ESA STSE PROJECT REGINA).
- Author
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Sasgen, Ingo, Martín-Español, Alba, Horvath, Alexander, Klemann, Volker, Petrie, Elizabeth J., Wouters, Bert, Horwath, Martin, Pail, Roland, Bamber, Jonathan L., Clarke, Peter J., Konrad, Hannes, and Drinkwater, Mark R.
- Abstract
The mass balance of the Antarctic ice sheet from satellite gravimetry, and to a lesser extent altimetry, observations remains uncertain due to the poorly known correction for the glacial isostatic adjustment of the solid Earth (GIA). Although much progress has been made in consistently modelling ice-sheet evolu-tion, related bedrock deformation and sea-level change, predictions of GIA remain ambiguous due to the lack of observational constraints in Antarctica. Here, we present an improved GIA estimate based on the joint inversion of GRACE, Envisat/ICESat and GPS measurements, making use of the different sen-sitivities of the satellite observations to surface-mass and solid Earth processes. We base our joint inver-sion on viscoelastic response functions to a disc load forcing, allowing us to account for lateral variations in the lithosphere thickness and mantle viscosity in Antarctica. Our estimate is able to reproduce extreme GPS-measured uplift rates (up to 3 cm yr-1) in the Amundsen Sea Embayment, indicating that large parts of the uplift are caused by GIA induced by recent load changes in the presence of a low-viscosity upper mantle. We compare our GIA inversion estimate with the prediction obtained with a coupled model of the ice sheet and solid Earth, as well as with published estimates. We evaluate its impact on the determination of ice-mass balance in Antarctica from gravimetry and altimetry. The results present-ed here are the final results of the Support To Science Element Project REGINA and its Supplementary Study of the European Space Agency, www.regina-science.eu. [ABSTRACT FROM AUTHOR]
- Published
- 2018
199. A NEW GLACIAL-ISOSTATIC ADJUSTMENT MODEL FOR GREENLAND CONSTRAINED BY GPS UPLIFT RATES AND RELATIVE SEA-LEVEL DATA.
- Author
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Sasgen, Ingo, Khan, Shafqat Abbas, Wouters, Bert, and Woodroffe, Sarah
- Abstract
The bedrock displacement recorded with GNET-GPS stations in Greenland reveal viscoelastic uplift rates that strongly contradict published predictions of glacial-isostatic adjustment (GIA). In particular, GPS provides evidence that GIA-induced uplift rates are considerably higher in the northwest and southeast of the ice sheet. Both regions are characterized by a lack of relative sea level (RSL) data to constrain the past ice sheet evolution and related viscoelastic displacement, thus causing large uncer-tainties in GIA predictions. Here, we develop a new GIA prediction by adjusting the geomorphological ice-sheet reconstruction of Fleming & Lambeck (2004) simultaneously to the RSL indicators and the newly available GPS data. Special focus lies on south Greenland, where an increasing number of high-quality RSL indicators from isolation basins suggest a fast relaxation of the solid Earth. This finding is consistent with global seismic models indicating a gradient in the lithosphere thickness and astheno-sphere viscosity from high values in the northwest to low values in the southeast. We demonstrate that the GIA prediction fits the GPS and RSL data significantly better for a lateral varying distribution of Earth model parameters. Finally, we evaluate the impact of our new GIA model on determining ice-mass bal-ances from GRACE. We show that commonly used GIA predictions have underestimated the solid Earth response by 17 Gt/yr, which is about 7 % of Greenland current ice-mass loss. [ABSTRACT FROM AUTHOR]
- Published
- 2018
200. Present and future ice mass loss of the North-Atlantic glaciers estimated from satellite observations.
- Author
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Wouters, Bert, Noël, Brice, Moholdt, Geir, Bamber, Jonathan, van Wessem, Melchior, Fettweis, Xavier, and van den Broeke, Michiel
- Subjects
- *
GLACIERS , *ICE , *ALBEDO , *ARTIFICIAL satellites , *ARTIFICIAL satellite launching , *GIFTS - Published
- 2018
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