scholarly journals Effects of polar ice sheets on global sea level in high-resolution greenhouse scenarios

2003 ◽  
Vol 108 (D5) ◽  
Author(s):  
Martin Wild
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Ice Sheets ◽  
Polar Ice ◽  
Polar Ice Sheets ◽  
Global Sea Level

Recent mass balance of polar ice sheets inferred from patterns of global sea-level change

Nature ◽  
2001 ◽  
Vol 409 (6823) ◽  
pp. 1026-1029 ◽  
Author(s):  
Jerry X. Mitrovica ◽  
Mark E. Tamisiea ◽  
James L. Davis ◽  
Glenn A. Milne
Keyword(s):  
Mass Balance ◽  
Sea Level ◽  
Ice Sheets ◽  
Sea Level Change ◽  
Polar Ice ◽  
Level Change ◽  
Polar Ice Sheets ◽  
Global Sea Level

New Space Observation of the Global Cryosphere

2021 ◽  
Author(s):  
Zhitong Yu ◽  
Luojia Hu ◽  
Yan Huang ◽  
Rong Ma ◽  
Peng Xiao ◽  
...  
Keyword(s):  
Sea Ice ◽  
Sea Level ◽  
Rapid Change ◽  
Ice Sheets ◽  
Dynamic Monitoring ◽  
Observation System ◽  
Polar Ice ◽  
Polar Ice Sheets ◽  
New Space ◽  
Wide Swath

<p>Quantifying changes in Earth’s ice sheets and identifying the climate drivers are central to improving sea level projections. But it is a pity that the future sea level is difficult to predicted. Space observation can provide global multiscale long-term continuous monitoring data. And it is very important for understanding intrinsic mechanisms, improve models and projections and analyze the impacts on human civilization.</p><p>Several satellites are applied for Global Cryosphere Watch, including sea ice extent and concentration, ice sheet elevation, glacier area and velocity. Although there are many variable can be measured by satellite sensors. But several variables need to improve the observing capability and developing new methods. Such as snow depth on ice, ice sheets thickness, and permafrost parameters. China has established high-resolution earth observation system to realize stereopsis and dynamic monitoring of the lands, the oceans and the atmosphere.</p><p>Currently, Qian Xuesen Laboratory working together with Sun Yat-sen University, is trying to design a new space observation system to support Three Poles Environment and Climate Changes project. We are conceptualizing two series satellites including FluxSats and BingSats for carbon/water cycle and cryosphere observations, respectively. To clarify the mechanism of the cryosphere carbon release and carbon sink effects of the oceans and ecosystems. We are developing a new lidar system for detecting the concentration and wind speed, and then atmospheric boundary layer flux exchange can be estimated. To understand the rapid change of the sea ice, such as drift, fragmentation and freeze. We need a short revisit and wide swath system capabilities. InSAR technology gives the digitial elevation of the ice surface. And temporal difference InSAR (DInSAR) shows the changes of elevation. BingSAT-Tomographic Observation of Polar Ice Sheets (TOPIS) achieves the tomographic observation of polar ice sheets with a wide swath and short revisit time. Over the polar regions, the CubeSats form a large cross-track baseline with the master satellite to realize the high two-dimensional spatial resolution with the along-track synthetic aperture. The MirrorSAR technology is utilized in BingSat-TOPIS to achieve time and phase synchronization more economically than the traditional bistatic radar. Sparse array and digital beamforming are also considered to significantly reduce the number of microsatellites, and achieve tomographic images of polar ice sheets.</p>

scholarly journals Formation of air clathrate hydrates in polar ice sheets: heterogeneous nucleation induced by micro-inclusions

2010 ◽  
Vol 56 (199) ◽  
pp. 917-921 ◽  
Author(s):  
Hiroshi Ohno ◽  
Vladimir Ya. Lipenkov ◽  
Takeo Hondoh
Keyword(s):  
High Resolution ◽  
Ice Sheets ◽  
Ice Cores ◽  
Transformation Process ◽  
Clathrate Hydrates ◽  
Air Bubbles ◽  
Polar Ice ◽  
High Resolution Mapping ◽  
Polar Ice Sheets ◽  
Resolution Mapping

AbstractTo investigate factors influencing nucleation of air clathrate hydrates in polar ice sheets, we have performed high-resolution mapping of the distributions of soluble impurities, air bubbles and air- hydrate crystals versus depth in the Dome Fuji Antarctic ice. Significant correlation observed between the concentrations of air inclusions and impurities in ice along with frequent occurrence of impurities inside hydrate crystals suggest that micro-inclusions promote hydrate nucleation in the ice matrix. Our observations also show that the diffusive macroscopic-scale redistribution of air constituents in ice in the bubble-hydrate transition zone is controlled by the original sedimentary layering of soluble impurities acting as nucleation helpers. The results of this study are important for the correct interpretation of high-resolution gas analyses of ice cores and for better understanding the global bubble-to-hydrate transformation process in polar ice sheets.

A global synthesis of the latest Ordovician Hirnantian brachiopod faunas

1988 ◽  
Vol 79 (4) ◽  
pp. 383-402 ◽  
Author(s):  
Rong Jia-yu ◽  
David A. T. Harper
Keyword(s):  
Spatial Distribution ◽  
North America ◽  
Sea Level ◽  
Ice Sheets ◽  
Polar Ice ◽  
Low Diversity ◽  
Polar Ice Sheets ◽  
Ecological Associations ◽  
Anticosti Island ◽  
Existing Data

ABSTRACTA global review of new and existing data on the distribution of uppermost Ordovician (Hirnantian) brachiopods indicates the existence of at least three biogeographically distinct faunas. The typical Hirnantia fauna characterised subtropical and temperate latitudes and comprised a variety of ecological associations; the fauna reached its acme during the bohemicus and uniformis zones. Atypical Hirnantia faunas, developed marginal to Gondwana, are of low diversity and have few species in common with the typical Hirnantia fauna; their spatial distribution probably marked the margin of the polar ice sheets. The extinction of the Hirnantia fauna occurred in response to changes in sea level. Diverse and quite different faunas, including those from the Midcontinent of North America, Kolyma, the Oslo Region and probably Anticosti Island, occupied equatorial latitudes during the latest Ordovician. The Holorhynchus fauna, on evidence to date, predates the Hirnantia fauna.

scholarly journals Representative surface snow density on the East Antarctic Plateau

2020 ◽  
Author(s):  
Alexander H. Weinhart ◽  
Johannes Freitag ◽  
Maria Hörhold ◽  
Sepp Kipfstuhl ◽  
Olaf Eisen
Keyword(s):  
Mass Balance ◽  
Sea Level ◽  
Ice Sheets ◽  
Surface Mass Balance ◽  
Snow Density ◽  
Polar Ice ◽  
Surface Mass ◽  
Antarctic Plateau ◽  
Surface Snow ◽  
Polar Ice Sheets

Abstract. Surface mass balance estimates of polar ice sheets are essential to estimate the contribution of ice sheets to sea level rise, in response global warming. One of the largest uncertainties in the interior regions of the ice sheets, such as the East Antarctic Plateau (EAP), is the determination of a precise surface snow density. Wrong estimates of snow and firn density can lead to significant underestimations of the surface mass balance. We present density data from snow profiles taken along an overland traverse in austral summer 2016/17 covering over 2000 km on the Dronning Maud Land plateau. The sampling strategy included investigation on various spatial scales, from regional to local, with sampling locations 100 km apart as well as a high-resolution study in a trench at 30° E 79° S with thirty 3 m deep snow profiles. Density of the surface snow profiles has been measured volumetrically as well as using μ-computer tomography. With an error of less than 2 %, the volumetric liner density provides higher precision than other sampling devices of smaller volume. With four spatially independent snow profiles per location we derive a representative and precise 1 m mean snow density with an error of less than 1.5 %. The average liner density along the traverse across the EAP is 355 kg m−3, which we identify as representative surface snow density between Kohnen station and Dome Fuji. The highest horizontal variability in density can be seen in the upper 0.3 m. Therefore, we do not recommend vertical sampling in intervals of less than several decimeters, as this does neither adequately cover seasonal variations in high accumulation areas nor the annual accumulation in low accumulation areas. From statistical analysis of the liner density on regional scale we identify representative spatial distributions of density based on geographical and thus climatic conditions. Our representative density of 355 kg m−3 is considerably different from the density of 320 kg m−3 provided by a regional climate model. This difference of more than 10 % indicates the necessity for further calibration of density parameterizations. The difference in the total mass equivalent of measured and modelled density yields a 3 % underestimation by models, which translates into 5 cm sea level equivalent. We do not find a statistically significant temporal trend in density changes over the last two decades. Our data provide a solid baseline for tuning parameterizations of the surface snow density for regions with low accumulation and low temperatures like the EAP to improve surface mass balance estimates of polar ice sheets.

scholarly journals Sea-level rise: Which is the role of glaciers and polar ice sheets?

2020 ◽  
Author(s):  
Francisco José Navarro
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheets ◽  
First Century ◽  
Extreme Wave ◽  
Polar Ice ◽  
Special Report ◽  
Polar Ice Sheets ◽  
Wave Heights

Sea-level has been rising at an accelerated rate during recent decades and is projected to continue increasing at an accelerated rate over the twenty-first century and beyond, mostly as a result of anthropogenic warming. A substantially raised sea level can have severe impacts on low-lying coastal areas, including coastal erosion and flooding of inhabited areas. Under continued climate warming, these impacts will be exacerbated by extreme meteorological events and extreme wave heights, posing severe risks to the human communities and coastal ecosystems. In this paper we review the recent advances on the contributions of glaciers and sheets to sea-level rise, in the light of the recently released IPCC Special Report on the Ocean and Cryosphere in a Changing Climate.

Shallow-Layers-Detection Ice Sounding Radar for Mapping of Polar Ice Sheets

2021 ◽  
pp. 1-10
Author(s):  
Bo Zhao ◽  
Yueyi Zhang ◽  
Shinan Lang ◽  
Yan Liu ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Ice Sheets ◽  
Polar Ice ◽  
Polar Ice Sheets
Sign in / Sign up

Export Citation Format

Share Document