scholarly journals Annual variations in GPS‐measured vertical displacements near Upernavik Isstrøm (Greenland) and contributions from surface mass loading

2017 ◽  
Vol 122 (1) ◽  
pp. 677-691 ◽  
Author(s):  
Lin Liu ◽  
Shfaqat Abbas Khan ◽  
Tonie Dam ◽  
Joseph Ho Yin Ma ◽  
Michael Bevis
Keyword(s):  
Mass Loading ◽  
Surface Mass ◽  
Annual Variations ◽  
Vertical Displacements

First glaciological investigations at Ridge B, central East Antarctica

2021 ◽  
pp. 1-10
Author(s):  
Alexey A. Ekaykin ◽  
Alexey V. Bolshunov ◽  
Vladimir Ya. Lipenkov ◽  
Mirko Scheinert ◽  
Lutz Eberlein ◽  
...  
Keyword(s):  
East Antarctica ◽  
Snow Density ◽  
Deep Drilling ◽  
Surface Mass ◽  
Annual Variations ◽  
First Results ◽  
Vostok Station ◽  
Water Stable Isotope ◽  
Isotope Content ◽  
Firn Core

Abstract The region of Ridge B in central East Antarctica is one of the last unexplored parts of the continent and, at the same time, ranks among the most promising places to search for Earth's oldest ice. In January 2020, we carried out the first scientific traverse from Russia's Vostok Station to the topographical dome of Ridge B (Dome B, 3807 m above sea level, 79.02°S, 93.69°E). The glaciological programme included continuous snow-radar profiling and geodetic positioning along the traverse's route, installation of snow stakes, measurements of snow density, collection of samples for stable water isotope and chemical analyses and drilling of a 20 m firn core. The first results of the traverse show that the surface mass balance at Dome B (2.28 g cm−2 year−1) is among the lowest in Antarctica. The firn temperature below the layer of annual variations is −58.1 ± 0.2°C. A very low value of heavy water stable isotope content (-58.2‰ for oxygen-18) was discovered at a distance of 170 km from Vostok Station. This work is the first step towards a comprehensive reconnaissance study of the Ridge B area aimed at locating the best site for future deep drilling for the oldest Antarctic ice.

scholarly journals Basis functions for the consistent and accurate representation of surface mass loading

2017 ◽  
Author(s):  
Peter Clarke ◽  
David Lavallee ◽  
Geoffrey Blewitt ◽  
Tonie van Dam
Keyword(s):  
Basis Functions ◽  
Mass Loading ◽  
Surface Mass ◽  
Accurate Representation

scholarly journals Analysis of the Potential Contributors to Common Mode Error in Chuandian Region of China

2020 ◽  
Vol 12 (5) ◽  
pp. 751
Author(s):  
Weijie Tan ◽  
Junping Chen ◽  
Danan Dong ◽  
Weijing Qu ◽  
Xueqing Xu
Keyword(s):  
Time Series ◽  
Soil Moisture ◽  
Principal Component ◽  
Mass Loading ◽  
Common Mode ◽  
Surface Mass ◽  
Common Mode Error ◽  
Comparison Results ◽  
Wide Range ◽  
Gps Time Series

Common mode error (CME) in Chuandian region of China is derived from 6-year continuous GPS time series and is identified by principal component analysis (PCA) method. It is revealed that the temporal behavior of the CME is not purely random, and contains unmodeled signals such as nonseasonal mass loadings. Its spatial distribution is quite uniform for all GPS sites in the region, and the first principal component, uniformly distributed in the region, has a spatial response of more than 70%. To further explore the potential contributors of CME, daily atmospheric mass loading and soil moisture mass loading effects are evaluated. Our results show that ~15% of CME can be explained by these daily surface mass loadings. The power spectral analysis is used to assess the CME. After removing atmospheric and soil moisture loadings from the CME, the power of the CME reduces in a wide range of frequencies. We also investigate the contribution of CME in GPS filtered residuals time series and it shows the Root Mean Squares (RMSs) of GPS time series are reduced by applying of the mass loading corrections in CME. These comparison results demonstrate that daily atmosphere pressure and the soil moisture mass loadings are a part of contributors to the CME in Chuandian region of China.

scholarly journals Climate and surface mass balance of Mocho Glacier, Chilean Lake District, 40°S

2016 ◽  
Vol 63 (238) ◽  
pp. 218-228 ◽  
Author(s):  
MARIUS SCHAEFER ◽  
JOSE LUIS RODRIGUEZ ◽  
MATTHIAS SCHEITER ◽  
GINO CASASSA
Keyword(s):  
Mass Balance ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Glacier Mass Balance ◽  
Surface Mass Balance ◽  
Climate Data ◽  
Lake District ◽  
Surface Mass ◽  
Annual Variations ◽  
Snow Drift

ABSTRACTWe present climate data, direct surface mass balance (SMB) observations and model results for Mocho Glacier in the Chilean Lake District. Mean annual temperature on a nunatak of Mocho Glacier at an elevation of ~2000 m was +2.6°C in 2006–15 and mean annual precipitation in Puerto Fuy (13 km from the glacier, at an elevation of 600 m) was 4000 mm for the same period. High interannual variations in the SMB of Mocho Glacier were observed. A simple SMB model is able to reproduce the observed annual variations in SMB, but fails to predict the steep observed mass-balance gradient. The average of the measured annual glacier mass balances in the four hydrological years 2009/10–2012/13 was −0.90 m w.e. a−1and the average modelled annual glacier mass balance 2006/07–2014/15 was −1.05 m w.e. a−1. The observed distributed ablation shows a clear altitudinal dependency, while accumulation is determined by patterns of snow drift as well. These patterns are only poorly represented in the model and have to be included in order to be able to reproduce a realistic SMB map of the glacier.

scholarly journals Basis functions for the consistent and accurate representation of surface mass loading

2007 ◽  
Vol 171 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Peter J. Clarke ◽  
David A. Lavallée ◽  
Geoff Blewitt ◽  
Tonie van Dam
Keyword(s):  
Basis Functions ◽  
Mass Loading ◽  
Surface Mass ◽  
Accurate Representation

scholarly journals Geophysical interpretation of GPS loading deformation over western Europe using GRACE measurements

2016 ◽  
Vol 59 (5) ◽  
Author(s):  
Songyun Wang ◽  
Jianli Chen ◽  
Jin Li ◽  
Xiaogong Hu ◽  
Shengnan Ni
Keyword(s):  
Western Europe ◽  
International Gnss Service ◽  
Satellite Gravity ◽  
Surface Mass ◽  
Grace Data ◽  
Surface Displacements ◽  
Residual Series ◽  
Vertical Displacements ◽  
Gravity Recovery ◽  
Improved Accuracy

<p>We analyze more than 10 years of Global Positioning System (GPS) height residuals and vertical displacements predicted from surface mass loading observed by the Gravity Recovery and Climate Experiment (GRACE) for 36 International GNSS Service (IGS) stations over Europe. Seasonal surface displacements, mostly due to atmospheric and hydrological loading, are significant in both GPS and GRACE measurements. With an extended time period, our new analysis based on release 05 GRACE data from Center for Space Research (CSR) shows considerably improved agreement between GPS and GRACE than that from previous studies, for not only annual but also interannual signals. The GPS height residual series at most stations exhibit reduced weighted root-mean-squares (WRMS) after removing GRACE-derived vertical displacements, which is attributed to improved accuracy of both GPS and GRACE data products. Furthermore, we demonstrate the necessity of reducing leakage bias in GRACE estimates for the study of surface loading deformation using GRACE satellite gravity observations.</p>

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