Download or read book Estimating Antarctic Ice Sheet Mass Balance from Gravimetry and Altimetry written by Rakia Meister and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Antartic Ice Sheet Mass Balance from Gravimetry and Altimetry written by and published by . This book was released on 2012 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Antartic Ice Sheet Mass Balance from Gravimetry and Altimetry written by Rakia Meister and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Decadal Mass Balance of the Antarctic Ice Sheet from Satellite Radar Altimetry and Its Contribution written by Yonghong Li and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, we estimated the decadal mass balance of the Antarctic ice sheet using the European Space Agency's ERS-1 and ERS-2 satellite radar altimeter data over the time period of 1992 - 2003. Several techniques are developed to improve the processing and analysis of both low and high resolution elevation change time series. Our research results show that the majority of the East Antarctica interior regions are thickening, and this is probably caused by increased precipitation. Finally, many coastal areas, especially in West Antarctica, are experiencing strongly negative elevation change. These thinning trends are probably due to high heat fluxes, ocean warming, and/or basal melting. The overall estimate of Antarctic elevation change north of 81.6°S corresponds to global sea level increase of 0.07 mm/yr based on the high-resolution interior and coastal results.
Download or read book Understanding ice sheet mass balance written by H.D. PRITCHARD and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Observations and Modelling of Surface Mass Balance Variations in East Antarctica written by Bianca Kallenberg and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mass balance changes of the Antarctic ice sheet are of significant interest due to its sensitivity to climatic changes and the contribution to changes in global sea level that is makes. In recent years, the Antarctic ice sheet has experienced increased temperatures inducing surface melting, accelerated ice flow and ice discharge but also an increase in accumulation. Geodetic observations suggest variable behaviour across the ice sheet, with an increase in mass over a vast area of East Antarctica and substantial thinning in West Antarctica. Despite considerable improvement on surface mass balance estimates using a variety of techniques, disparity remains mainly due to uncertainties of each method and the unknown contribution of glacial isostatic adjustment, the response of the lithosphere to prolonged surface loads. Estimates of bedrock uplift rates are limited and existing models are poorly constrained due to the lack of observations as a result of the extensive permanent ice coverage in Antarctica. This study investigates the possibility of combining and comparing altimetry and gravity observations by employing a regional climate model to simulate near surface climate and firn compaction, to separate the contributing ice sheet mass balance components of surface mass, firn compaction, ice dynamics and glacial isostatic adjustment within the observed signals. The region of interest covers an area including Enderby, Kemp and Mac.Robertson Land, in East Antarctica, an area where an increase in ice mass and ice height has been recorded over the past decade. Despite the general agreement that the positive signal is primarily related to increased snowfall, large uncertainties remain in bedrock uplift rates in this region due to the lack of observations. Estimates of ice dynamic rates are obtained by removing modelled surface elevation variations, due to surface mass and firn compaction, from altimetry observations, which are subsequently employed in models of mass variations to compare with gravimetric observations.
Download or read book Remote Sensing by Satellite Gravimetry written by Thomas Gruber and published by MDPI. This book was released on 2021-01-19 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last two decades, satellite gravimetry has become a new remote sensing technique that provides a detailed global picture of the physical structure of the Earth. With the CHAMP, GRACE, GOCE and GRACE Follow-On missions, mass distribution and mass transport in the Earth system can be systematically observed and monitored from space. A wide range of Earth science disciplines benefit from these data, enabling improvements in applied models, providing new insights into Earth system processes (e.g., monitoring the global water cycle, ice sheet and glacier melting or sea-level rise) or establishing new operational services. Long time series of mass transport data are needed to disentangle anthropogenic and natural sources of climate change impacts on the Earth system. In order to secure sustained observations on a long-term basis, space agencies and the Earth science community are currently planning future satellite gravimetry mission concepts to enable higher accuracy and better spatial and temporal resolution. This Special Issue provides examples of recent improvements in gravity observation techniques and data processing and analysis, applications in the fields of hydrology, glaciology and solid Earth based on satellite gravimetry data, as well as concepts of future satellite constellations for monitoring mass transport in the Earth system.
Download or read book Time Series Analysis of ERS 2 Elevation Data for Estimation of Antarctic Ice Sheet Mass Balance written by Adam Christopher Ferguson and published by . This book was released on 2002 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polar Environments and Global Change written by Roger G. Barry and published by Cambridge University Press. This book was released on 2018-08-09 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surveys atmospheric, oceanic and cryospheric processes, present and past conditions, and changes in polar environments.
Download or read book Mass Balance of Greenland and Antarctica Ice Sheets from Satellite Gravimetry written by Yu Zhang (Ph. D. in geodetic science) and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative assessment of the mass balance of polar ice sheets plays an important role in better understanding the response of ice sheets to anthropogenic climate change, the present-day and future global sea level change, and interactions between the ice sheets and the atmosphere, ocean and the solid Earth. In this study, I investigate the mass balance of Greenland and Antarctica ice sheets using Gravity Recovery And Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) twin-satellite missions gravity data from April 2002 to August 2020. Auxiliary gravity data from the Swarm mission 3-satellite constellation are also used to support the analysis bridging the GRACE/GRACE-FO data gap (July 2017 to May 2018). Ensemble models are composed combining the official GRACE temporal gravity solutions from CSR, GFZ, JPL and the in-house developed GRACE models using the improved energy balance approach (EBA). The improved atmospheric de-aliasing data produced using the ECMWF (European Centre for Medium-Range Weather Forecasts) Reanalysis 5th Generation (ERA5) data product, and 3-dimensional atmosphere mass computational algorithms are collectively used. The Swarm gravity models are also ensemble of four solutions produced from the kinematic orbit data using four different gravity recovery methods. Post-processing of the gravity models includes replacing low degree spherical harmonic terms (geocenter motions, J2 and J3), destriping filtering, Gaussian smoothing, glacial isostatic adjustment (GIA), forward modeling based signal leakage reduction and ellipsoidal correction. The satellite gravimetric data show that during the period of 2002/04-2020/08, Greenland and Antarctica ice sheets experience rapid mass losses at mean rates of -235.6±3.8 Gt/yr and -122.6±4.6 Gt/yr respectively, equivalent to 0.65 mm/yr and 0.34 mm/yr global sea level changes. In spatial domain, the southern part (including southeast and southwest regions) of Greenland contributes 52.3% of the total Greenland mass loss rate. The West Antarctica (WAIS) losses mass at mean rate of -149.3±3.4 Gt/yr, which accounts for 121.8% of the total Antarctica mass loss rate. The mass gain of +57.2±3.4 Gt/yr in East Antarctica (EAIS) compensates 46.7% of the mass imbalance. Greenland has record-breaking annual mass loss of -461.2±51.8 Gt in 2019. Similarly, Antarctica annual mass loss also sets record at -379.1±90.3 Gt in 2019, mostly due to the abnormal and unprecedented mass loss in EAIS which will be further investigated in the future incorporating independent surface mass balance (SMB) and ice discharge data. The noted abrupt and nonlinear changes in the mass balance of polar ice sheets are presumably due to an increasingly warmer Earth-induced climate episodes with varying time series, from a few years to much longer time periods, along to intraseasonal or shorter changes. It is concluded while the satellite gravimetry climate record is approaching a two decade data span, much longer data are needed to improve our understanding in the complex dynamics of these polar ice sheets responding to climate change.
Download or read book Model Estimates of the Mass Balance of the Greenland and Antarctic Ice Sheets written by Véronique Bugnion and published by . This book was released on 1999 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Surface Mass Balance of the Antarctic Ice Sheet written by Nicole Petra Marie van Lipzig and published by . This book was released on 1999 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleoclimatology written by Gilles Ramstein and published by Springer Nature. This book was released on 2020-11-09 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume book provides a comprehensive, detailed understanding of paleoclimatology beginning by describing the “proxy data” from which quantitative climate parameters are reconstructed and finally by developing a comprehensive Earth system model able to simulate past climates of the Earth. It compiles contributions from specialists in each field who each have an in-depth knowledge of their particular area of expertise. The first volume is devoted to “Finding, dating and interpreting the evidence”. It describes the different geo-chronological technical methods used in paleoclimatology. Different fields of geosciences such as: stratigraphy, magnetism, dendrochronology, sedimentology, are drawn from and proxy reconstructions from ice sheets, terrestrial (speleothems, lakes, and vegetation) and oceanic data, are used to reconstruct the ancient climates of the Earth. The second volume, entitled “Investigation into ancient climates,” focuses on building comprehensive models of past climate evolution. The chapters are based on understanding the processes driving the evolution of each component of the Earth system (atmosphere, ocean, ice). This volume provides both an analytical understanding of each component using a hierarchy of models (from conceptual to very sophisticated 3D general circulation models) and a synthetic approach incorporating all of these components to explore the evolution of the Earth as a global system. As a whole this book provides the reader with a complete view of data reconstruction and modeling of the climate of the Earth from deep time to present day with even an excursion to include impacts on future climate.
Download or read book Mass balance of the Antarctic ice sheet written by D.J. WINGHAM and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recommendations for the collection and synthesis of Antarctic Ice Sheet mass balance data written by ISMASS COMMITTEE. and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravity Geoid and Earth Observation written by Stelios P. Mertikas and published by Springer Science & Business Media. This book was released on 2010-06-25 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: These Proceedings include the written version of papers presented at the IAG International Symposium on "Gravity, Geoid and Earth Observation 2008". The Symposium was held in Chania, Crete, Greece, 23-27 June 2008 and organized by the Laboratory of Geodesy and Geomatics Engineering, Technical University of Crete, Greece. The meeting was arranged by the International Association of Geodesy and in particular by the IAG Commission 2: Gravity Field. The symposium aimed at bringing together geodesists and geophysicists working in the general areas of gravity, geoid, geodynamics and Earth observation. Besides covering the traditional research areas, special attention was paid to the use of geodetic methods for: Earth observation, environmental monitoring, Global Geodetic Observing System (GGOS), Earth Gravity Models (e.g., EGM08), geodynamics studies, dedicated gravity satellite missions (i.e., GOCE), airborne gravity surveys, Geodesy and geodynamics in polar regions, and the integration of geodetic and geophysical information.
Download or read book Mass Balance of Antarctica and Sea Level Change written by C. R. Bentley and published by . This book was released on 1992 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall mass balance of the Antarctic ice sheet has been estimated by comparison of the best available data on input in the form of snowfall with output in the form of ice flux through gates at or near the margin of the ice sheet. Surface melt is a negligible contributor to mass balance and has been ignored. Bottom melt under large ice shelves remains a major source of uncertainty. We conclude that there is probably an excess input of 2-25% of the total input, equivalent to a sea level lowering of 0.1-1.1 mm yr-l. Although errors remain, it becomes increasingly clear that an antarctic contribution to current sea level rise is unlikely. We attribute a reported iceberg flux that is larger than the mass input to a non-equilibrium breakback of the fronts of the ice shelves.
