A Fulcrum Approach To Assessing Source-To-Sink Mass Balance Using Channel Paleohydrologic Paramaters Derivable From Common Fluvial Data Sets With An Example From the Cretaceous of Egypt

2014 ◽  
Vol 84 (5) ◽  
pp. 349-372 ◽  
Author(s):  
J. Holbrook ◽  
H. Wanas
Keyword(s):  
Mass Balance ◽  
Data Sets ◽  
Source To Sink

scholarly journals Mass Balance of Cenozoic Andes-Amazon Source to Sink System—Marañón Basin, Peru

Geosciences ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 167 ◽  
Author(s):  
Gérôme Calvès ◽  
Ysabel Calderón ◽  
Christian Hurtado Enriquez ◽  
Stéphane Brusset ◽  
William Santini ◽  
...  
Keyword(s):  
Mass Balance ◽  
Source To Sink

scholarly journals The modelled surface mass balance of the Antarctic Peninsula at 5.5 km horizontal resolution

2016 ◽  
Vol 10 (1) ◽  
pp. 271-285 ◽  
Author(s):  
J. M. van Wessem ◽  
S. R. M. Ligtenberg ◽  
C. H. Reijmer ◽  
W. J. van de Berg ◽  
M. R. van den Broeke ◽  
...  
Keyword(s):  
Mass Balance ◽  
Antarctic Peninsula ◽  
Climate Model ◽  
Horizontal Resolution ◽  
Surface Mass Balance ◽  
Data Sets ◽  
High Accumulation ◽  
Surface Mass ◽  
Meltwater Runoff ◽  
The Antarctic

Abstract. This study presents a high-resolution (∼  5.5 km) estimate of surface mass balance (SMB) over the period 1979–2014 for the Antarctic Peninsula (AP), generated by the regional atmospheric climate model RACMO2.3 and a firn densification model (FDM). RACMO2.3 is used to force the FDM, which calculates processes in the snowpack, such as meltwater percolation, refreezing and runoff. We evaluate model output with 132 in situ SMB observations and discharge rates from six glacier drainage basins, and find that the model realistically simulates the strong spatial variability in precipitation, but that significant biases remain as a result of the highly complex topography of the AP. It is also clear that the observations significantly underrepresent the high-accumulation regimes, complicating a full model evaluation. The SMB map reveals large accumulation gradients, with precipitation values above 3000 mm we yr−1 in the western AP (WAP) and below 500 mm we yr−1 in the eastern AP (EAP), not resolved by coarser data sets such as ERA-Interim. The average AP ice-sheet-integrated SMB, including ice shelves (an area of 4.1  ×  105 km2), is estimated at 351 Gt yr−1 with an interannual variability of 58 Gt yr−1, which is dominated by precipitation (PR) (365 ± 57 Gt yr−1). The WAP (2.4  ×  105 km2) SMB (276 ± 47 Gt yr−1), where PR is large (276 ± 47 Gt yr−1), dominates over the EAP (1.7  ×  105 km2) SMB (75 ± 11 Gt yr−1) and PR (84 ± 11 Gt yr−1). Total sublimation is 11 ± 2 Gt yr−1 and meltwater runoff into the ocean is 4 ± 4 Gt yr−1. There are no significant trends in any of the modelled AP SMB components, except for snowmelt that shows a significant decrease over the last 36 years (−0.36 Gt yr−2).

scholarly journals Recent mass balance of the Purogangri Ice Cap, central Tibetan Plateau, by means of differential X-band SAR interferometry

2013 ◽  
Vol 7 (5) ◽  
pp. 1623-1633 ◽  
Author(s):  
N. Neckel ◽  
A. Braun ◽  
J. Kropáček ◽  
V. Hochschild
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Sar Interferometry ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Fine Grid ◽  
Mass Budget ◽  
Ice Cap ◽  
Time Period ◽  
X Band

Abstract. Due to their remoteness, altitude and harsh climatic conditions, little is known about the glaciological parameters of ice caps on the Tibetan Plateau. This study presents a geodetic mass balance estimate of the Purogangri Ice Cap, Tibet's largest ice field between 2000 and 2012. We utilized data from the actual TerraSAR-X mission and its add-on for digital elevation measurements and compared it with elevation data from the Shuttle Radar Topography Mission. The employed data sets are ideal for this approach as both data sets were acquired at X-band at nearly the same time of the year and are available at a fine grid spacing. In order to derive surface elevation changes we employed two different methods. The first method is based on differential synthetic radar interferometry while the second method uses common DEM differencing. Both approaches revealed a slightly negative mass budget of −44 ± 15 and −38 ± 23 mm w.eq. a−1 (millimeter water equivalent) respectively. A slightly negative trend of −0.15 ± 0.01 km2 a−1 in glacier extent was found for the same time period employing a time series of Landsat data. Overall, our results show an almost balanced mass budget for the studied time period. Additionally, we detected one continuously advancing glacier tongue in the eastern part of the ice cap.

scholarly journals Long-term records of glacier surface velocities in the Ötztal Alps (Austria)

2019 ◽  
Author(s):  
Martin Stocker-Waldhuber ◽  
Andrea Fischer ◽  
Kay Helfricht ◽  
Michael Kuhn
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
Data Sets ◽  
Climatic Forcing ◽  
Glacier Surface ◽  
Ice Flow ◽  
Strong Indicator ◽  
Length Changes ◽  
Flow Velocities

Abstract. Climatic forcing affects glacier mass balance and ice flow dynamics on different time scales, resulting in length changes. Mass Balance and length changes are operationally used for glacier monitoring, whereas only a few time series of glacier dynamics have been recorded. With more than 100 years of measurements of ice flow velocities at stakes and stone lines on Hintereisferner and more than 50 years on Kesselwandferner, annual velocity and glacier fluctuation records have similar lengths. Subseasonal variations of ice flow velocities have been measured on Gepatschferner and Taschachferner for nearly a decade. The ice flow velocities on Hintereisferner and especially on Kesselwandferner show great variations between advancing and retreating periods, with magnitudes increasing from the highest to the lowest stakes, making ice flow records at ablation stakes a very sensitive indicator of glacier state. Since the end of the latest glacier advances from the 1970s to the 1980s, the ice flow velocities have decreased continuously, a strong indicator of the negative mass balances of the glaciers in recent decades. The velocity data sets of the four glaciers are available at https://doi.pangaea.de/10.1594/PANGAEA.896741.

scholarly journals Exploring uncertainty in glacier mass balance modelling with Monte Carlo simulation

2008 ◽  
Vol 2 (3) ◽  
pp. 447-485 ◽  
Author(s):  
H. Machguth ◽  
R. S. Purves ◽  
J. Oerlemans ◽  
M. Hoelzle ◽  
F. Paul
Keyword(s):  
Monte Carlo ◽  
Mass Balance ◽  
Meteorological Data ◽  
Global Radiation ◽  
Systematic Errors ◽  
Uncertainty Assessment ◽  
Balance Model ◽  
Order Estimate ◽  
Glacier Mass Balance ◽  
Data Sets

Abstract. By means of Monte Carlo simulations we calculated uncertainty in modelled cumulative mass balance over 400 days at one particular point on the tongue of Morteratsch Glacier, Switzerland, using a glacier energy balance model of intermediate complexity. Before uncertainty assessment, the model was tuned to observed mass balance for the investigated time period and its robustness was tested by comparing observed and modelled mass balance over 11 years, yielding very small deviations. Both systematic and random uncertainties are assigned to twelve input parameters and their respective values estimated from the literature or from available meteorological data sets. The calculated overall uncertainty in the model output is dominated by systematic errors and amounts to 0.7 m w.e. or approximately 10% of total melt over the investigated time span. In order to provide a first order estimate on variability in uncertainty depending on the quality of input data, we conducted a further experiment, calculating overall uncertainty for different levels of uncertainty in measured global radiation and air temperature. Our results show that the output of a well calibrated model is subject to considerable uncertainties, in particular when applied for extrapolation in time and space where systematic errors are likely to be an important issue.

scholarly journals Sensitivity of inverse glacial isostatic adjustment estimates over Antarctica

2020 ◽  
Vol 14 (1) ◽  
pp. 349-366
Author(s):  
Matthias O. Willen ◽  
Martin Horwath ◽  
Ludwig Schröder ◽  
Andreas Groh ◽  
Stefan R. M. Ligtenberg ◽  
...  
Keyword(s):  
Mass Balance ◽  
Bias Correction ◽  
Total Mass ◽  
Process Models ◽  
Mass Change ◽  
Quality Data ◽  
Data Sets ◽  
Glacial Isostatic Adjustment ◽  
Satellite Gravimetry ◽  
Isostatic Adjustment

Abstract. Glacial isostatic adjustment (GIA) is a major source of uncertainty for ice and ocean mass balance estimates derived from satellite gravimetry. In Antarctica the gravimetric effect of cryospheric mass change and GIA are of the same order of magnitude. Inverse estimates from geodetic observations hold some promise for mass signal separation. Here, we investigate the combination of satellite gravimetry and altimetry and demonstrate that the choice of input data sets and processing methods will influence the resultant GIA inverse estimate. This includes the combination that spans the full GRACE record (April 2002–August 2016). Additionally, we show the variations that arise from combining the actual time series of the differing data sets. Using the inferred trends, we assess the spread of GIA solutions owing to (1) the choice of different degree-1 and C20 products, (2) viable candidate surface-elevation-change products derived from different altimetry missions corresponding to different time intervals, and (3) the uncertainties associated with firn process models. Decomposing the total-mass signal into the ice mass and the GIA components is strongly dependent on properly correcting for an apparent bias in regions of small signal. Here our ab initio solutions force the mean GIA and GRACE trend over the low precipitation zone of East Antarctica to be zero. Without applying this bias correction, the overall spread of total-mass change and GIA-related mass change using differing degree-1 and C20 products is 68 and 72 Gt a−1, respectively, for the same time period (March 2003–October 2009). The bias correction method collapses this spread to 6 and 5 Gt a−1, respectively. We characterize the firn process model uncertainty empirically by analysing differences between two alternative surface mass balance products. The differences propagate to a 10 Gt a−1 spread in debiased GIA-related mass change estimates. The choice of the altimetry product poses the largest uncertainty on debiased mass change estimates. The spread of debiased GIA-related mass change amounts to 15 Gt a−1 for the period from March 2003 to October 2009. We found a spread of 49 Gt a−1 comparing results for the periods April 2002–August 2016 and July 2010–August 2016. Our findings point out limitations associated with data quality, data processing, and correction for apparent biases.

scholarly journals Exploring uncertainty in glacier mass balance modelling with Monte Carlo simulation

2008 ◽  
Vol 2 (2) ◽  
pp. 191-204 ◽  
Author(s):  
H. Machguth ◽  
R. S. Purves ◽  
J. Oerlemans ◽  
M. Hoelzle ◽  
F. Paul
Keyword(s):  
Monte Carlo ◽  
Mass Balance ◽  
Meteorological Data ◽  
Global Radiation ◽  
Systematic Errors ◽  
Uncertainty Assessment ◽  
Balance Model ◽  
Order Estimate ◽  
Glacier Mass Balance ◽  
Data Sets

Abstract. By means of Monte Carlo simulations we calculated uncertainty in modelled cumulative mass balance over 400 days at one particular point on the tongue of Morteratsch Glacier, Switzerland, using a glacier energy balance model of intermediate complexity. Before uncertainty assessment, the model was tuned to observed mass balance for the investigated time period and its robustness was tested by comparing observed and modelled mass balance over 11 years, yielding very small deviations. Both systematic and random uncertainties are assigned to twelve input parameters and their respective values estimated from the literature or from available meteorological data sets. The calculated overall uncertainty in the model output is dominated by systematic errors and amounts to 0.7 m w.e. or approximately 10% of total melt over the investigated time span. In order to provide a first order estimate on variability in uncertainty depending on the quality of input data, we conducted a further experiment, calculating overall uncertainty for different levels of uncertainty in measured global radiation and air temperature. Our results show that the output of a well calibrated model is subject to considerable uncertainties, in particular when applied for extrapolation in time and space where systematic errors are likely to be an important issue.

scholarly journals The Rofental: a high Alpine research basin (1890 m – 3770 m a.s.l.) in the Ötztal Alps (Austria) with over 150 years of hydro-meteorological and glaciological observations

2017 ◽  
Author(s):  
Ulrich Strasser ◽  
Thomas Marke ◽  
Ludwig Braun ◽  
Heidi Escher-Vetter ◽  
Irmgard Juen ◽  
...  
Keyword(s):  
Mass Balance ◽  
Laser Scanner ◽  
Longwave Radiation ◽  
Water Levels ◽  
Original Research ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Data Sets ◽  
Data Set ◽  
Entire Area

Abstract. A comprehensive hydrometeorological and glaciological data set is presented, originating from a multitude of recordings at several intensively operated research sites in the Rofental (1891–3772 m a.s.l., Ötztal Alps, Austria). The data sets are spanning a period of 150 years and hence represent a unique, worldwide unprecedented pool of high mountain observations. Their collection has originally been initiated to support the scientific investigation of the glaciers Hintereis-, Kesselwand- and Vernagtferner. Later, additional measurements of meteorological and hydrological variables have been undertaken; data now comprise records of temperature, relative humidity, short- and longwave radiation, wind speed and direction, air pressure, precipitation and water levels. For the glaciers, annual mass balance, glacier front variation and flow velocities as well as photographic images of the glacier status have been recorded. Since 2001, a series of distributed (airborne and terrestrial) laserscans has been processed. Most recently, a permanent terrestrial laser scanner installed on "Im hintern Eis" (3244 m a.s.l.) enables to continuously observe almost the entire area of Hintereisferner. The data and research undertaken at the sites of investigation enable combined research of atmospheric, cryospheric and hydrological processes in complex terrain, and support the development of several state-of-the art hydroclimatological and glacier mass balance models. The institutions taking part in the Rofental research framework have joined to a cooperation consortium and promote their site in several international research initiatives. In the framework of INARCH, all original research data sets are now provided to the scientific community according to the Creative Commons Attribution License by means of the PANGAEA repository (https://doi.org/doi:10.1594/PANGAEA.876120).

scholarly journals Sensitivity of inverse glacial isostatic adjustment estimates over Antarctica

2019 ◽  
Author(s):  
Matthias O. Willen ◽  
Martin Horwath ◽  
Ludwig Schröder ◽  
Andreas Groh ◽  
Stefan R. M. Ligtenberg ◽  
...  
Keyword(s):  
Mass Balance ◽  
Bias Correction ◽  
Total Mass ◽  
Mass Change ◽  
Data Sets ◽  
Glacial Isostatic Adjustment ◽  
Satellite Gravimetry ◽  
Isostatic Adjustment ◽  
Time Period ◽  
Combining Data

Abstract. Glacial isostatic adjustment (GIA) is a major source of uncertainty in estimated ice and ocean mass balance that are based on satellite gravimetry. In particular over Antarctica the gravimetric effect of cryospheric mass change and GIA are of the same order of magnitude. Inverse estimates from geodetic observations are promising for separating the two superimposed mass signals. Here, we investigate the combination of satellite gravimetry and altimetry and how the choice of input data sets and processing details affect the inverse GIA estimates. This includes the combination for almost full GRACE lifespan (2002-04/2016-08). Further we show results from combining data sets on time-series level. Specifically on trend level, we assess the spread of GIA solutions that arises from (1) the choice of different degree-1 and C20 products, (2) different surface elevation change products derived from different altimetry missions and associated to different time intervals, and (3) the uncertainty of firn-process models. The decomposition of the total-mass signal into the ice-mass signal and the apparent GIA-mass signal depends strongly on correcting for apparent biases in initial solutions by forcing the mean GIA and GRACE trend over the low precipitation zone of East Antarctica to be zero. Prior to bias correction, the overall spread of total-mass change and apparent GIA-mass change using differing degree-1 and C20 products is 68 and 72 Gt a−1, respectively, for the same time period (2003-03/2009-10). The bias correction suppresses this spread to 6 and 5 Gt a−1, respectively. We characterise the firn-process model uncertainty empirically by analysing differences between two alternative surface-mass-balance products. The differences propagate to a 21 Gt a−1 spread in apparent GIA-mass-change estimates. The choice of the altimetry product poses the largest uncertainty on debiased mass-change estimates. The overall spread of debiased GIA-mass change amounts to 18 and 49 Gt a−1 for a fixed time period (2003-03/2009-10) and various time periods, respectively. Our findings point out limitations associated with data processing, correction for apparent biases, and time dependency.

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