{"dp_type": "Project", "free_text": "Accumulation processes"}
[{"awards": "1654922 de la Pena, Santiago", "bounds_geometry": "POINT(0 -90)", "dataset_titles": " South Pole Weather and Accumulation Measurements 2017-2020", "datasets": [{"dataset_uid": "601591", "doi": "10.15784/601591", "keywords": "Accumulation; Antarctica; Snow; South Pole; Surface Mass Balance", "people": "de la Pe\u00f1a, Santiago", "repository": "USAP-DC", "science_program": null, "title": " South Pole Weather and Accumulation Measurements 2017-2020", "url": "https://www.usap-dc.org/view/dataset/601591"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "Non-Technical Description: Snow accumulation in the interior of the Antarctic Ice Sheet, and how much snow is redistributed by wind are important components of the climate system of Antarctica, yet remain largely unknown. Because of the extreme meteorological conditions found in Antarctica, direct observations of snowfall and related weather are few, leaving a gap in the regional climate records in the continent. Snow accumulation across the Antarctic Ice Sheet is a critical component for the assessment of the contribution of Antarctica to sea level rise, and accurate measurements are required to evaluate results from regional climate models, used to reconstruct climate trends of the recent past for the whole ice sheet. Owing to the size of Antarctica alone, small fluctuations in the total snow accumulation at the surface have a significant effect on the mass budget of the ice sheet and thus on global sea level. In this work will develop an instrument suite for deployment at the South Pole research station in Antarctica. The monitoring station will have new state-of-the-art sensors will record measurements of weather, snow accumulation, and structural conditions within the layer of packed snow. The autonomous system will be tested in the coldest and darkest winter on the planet, and will provide the first continuous measurements of snow accumulation processes in the interior of the ice sheet, which will be used to validate atmospheric and regional climate models. Technical Description: The overarching goal of the proposed work is to improve our understanding of the spatiotemporal variability in ice-sheet surface mass balance and densification rates within the layer of firn, a layer roughly 100 m thick consisting of the buried and compacted snow that has yet to densify into solid ice. For this, we will A) design and install a cost-efficient, reliable, and easily deployable surface mass balance and firn monitoring system for Antarctica; B) adapt the system to operate autonomously for long periods of time under the harshest meteorological conditions; C) use observations for evaluation of surface mass balance simulated by atmospheric reanalyzes and regional climate model; and D) measure the surface mass balance, surface density, and firn compaction rates to derive ice sheet surface elevation change in areas with low ice dynamics. The set up of the monitoring station is unique in that it is able to monitor separately height change due to surface mass balance variability and absolute surface mass balance, the latter in units of water equivalence, and differentiation of the two is crucial for understanding the role of surface processes in ice sheet mass balance. An installed sonic ranger will provide hourly measurements of surface height change that is due to snow accumulation. Surface height change alone is not sufficient to evaluate atmospheric models of surface mass balance, which is measured in in units of mass; a key variable missing is density. To overcome this, the system will be equipped with a SnowFox sensor that is able to capture the variations in surface mass balance in terms of mass through time. Combining the height change with mass change will allow us to determine the density of the material as well, which is very important for conversion of observed height changes due to surface processes into mass changes. Therefore, we aim to better evaluate the short-term variability in surface height and mass fluctuations due to surface mass balance to improve our understanding of the total mass change and to evaluate atmospheric models, which are typically used for ice sheet-wide mass balance studies.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "South Pole; SNOW", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "de la Pe\u00f1a, Santiago", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "EAGER: An Operational System to Measure Surface Mass Balance Deep in the Interior of the Antarctic Ice Sheet", "uid": "p0010360", "west": 0.0}, {"awards": "9909484 Lal, Devendra", "bounds_geometry": "POINT(106.133 -76.083)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 02 Oct 2006 00:00:00 GMT", "description": "9909484 Lal This award is for support for three years of funding to develop a history of snow accumulation and physical processes occurring in the upper layers of ice deposited at several sites in Antarctica, using cosmogenic in-situ Carbon-14 (14C) and cosmogenic Beryllium-10 (10Be) as radiotracers. The proposed research emerges from recent studies of cosmogenic in-situ 14C in GISP2 Holocene and several Antarctic ice samples, which revealed marked differences in the 14C concentrations in the samples, compared to the theoretically expected values. The GISP2 samples have about the expected amount of 14C but the Antarctic samples are deficient by 30-50% or more. These results suggest that in slowly accumulating ice samples (such as occur in Antarctica), the cosmic ray implanted 14C is somehow partially lost, but quantitatively preserved in samples from areas of high accumulation. These results suggest that after deposition of the cosmogenic 14C, its concentration is decreased in firn due to processes such as recrystallization, sublimation/evaporation and redeposition. In order to quantify these processes, the atmospheric cosmogenic 10Be in ice samples will also be measured. Since 10Be and 14C have different responses to the firnification processes, their simultaneous study can help to elucidate the nature and importance of these processes. Samples from Taylor Dome, Vostok and Siple Dome will all be studied.", "east": 106.133, "geometry": "POINT(106.133 -76.083)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Radiotracers; Firn; Holocene; Taylor Dome; Vostok; Siple Dome; Cosmogenic 14 C; Carbon-14; Accumulation; 10Be", "locations": "Siple Dome; Taylor Dome; Vostok", "north": -76.083, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lal, Devendra", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -76.083, "title": "Firn Accumulation Processes in Taylor Dome, Vostok and Siple Dome Ice Using Cosmogenic 14 C and 10Be as Tracers", "uid": "p0000732", "west": 106.133}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||
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EAGER: An Operational System to Measure Surface Mass Balance Deep in the Interior of the Antarctic Ice Sheet
|
1654922 |
2022-08-02 | de la Peña, Santiago |
|
Non-Technical Description: Snow accumulation in the interior of the Antarctic Ice Sheet, and how much snow is redistributed by wind are important components of the climate system of Antarctica, yet remain largely unknown. Because of the extreme meteorological conditions found in Antarctica, direct observations of snowfall and related weather are few, leaving a gap in the regional climate records in the continent. Snow accumulation across the Antarctic Ice Sheet is a critical component for the assessment of the contribution of Antarctica to sea level rise, and accurate measurements are required to evaluate results from regional climate models, used to reconstruct climate trends of the recent past for the whole ice sheet. Owing to the size of Antarctica alone, small fluctuations in the total snow accumulation at the surface have a significant effect on the mass budget of the ice sheet and thus on global sea level. In this work will develop an instrument suite for deployment at the South Pole research station in Antarctica. The monitoring station will have new state-of-the-art sensors will record measurements of weather, snow accumulation, and structural conditions within the layer of packed snow. The autonomous system will be tested in the coldest and darkest winter on the planet, and will provide the first continuous measurements of snow accumulation processes in the interior of the ice sheet, which will be used to validate atmospheric and regional climate models. Technical Description: The overarching goal of the proposed work is to improve our understanding of the spatiotemporal variability in ice-sheet surface mass balance and densification rates within the layer of firn, a layer roughly 100 m thick consisting of the buried and compacted snow that has yet to densify into solid ice. For this, we will A) design and install a cost-efficient, reliable, and easily deployable surface mass balance and firn monitoring system for Antarctica; B) adapt the system to operate autonomously for long periods of time under the harshest meteorological conditions; C) use observations for evaluation of surface mass balance simulated by atmospheric reanalyzes and regional climate model; and D) measure the surface mass balance, surface density, and firn compaction rates to derive ice sheet surface elevation change in areas with low ice dynamics. The set up of the monitoring station is unique in that it is able to monitor separately height change due to surface mass balance variability and absolute surface mass balance, the latter in units of water equivalence, and differentiation of the two is crucial for understanding the role of surface processes in ice sheet mass balance. An installed sonic ranger will provide hourly measurements of surface height change that is due to snow accumulation. Surface height change alone is not sufficient to evaluate atmospheric models of surface mass balance, which is measured in in units of mass; a key variable missing is density. To overcome this, the system will be equipped with a SnowFox sensor that is able to capture the variations in surface mass balance in terms of mass through time. Combining the height change with mass change will allow us to determine the density of the material as well, which is very important for conversion of observed height changes due to surface processes into mass changes. Therefore, we aim to better evaluate the short-term variability in surface height and mass fluctuations due to surface mass balance to improve our understanding of the total mass change and to evaluate atmospheric models, which are typically used for ice sheet-wide mass balance studies. | POINT(0 -90) | POINT(0 -90) | false | false | |||
Firn Accumulation Processes in Taylor Dome, Vostok and Siple Dome Ice Using Cosmogenic 14 C and 10Be as Tracers
|
9909484 |
2006-10-02 | Lal, Devendra | No dataset link provided | 9909484 Lal This award is for support for three years of funding to develop a history of snow accumulation and physical processes occurring in the upper layers of ice deposited at several sites in Antarctica, using cosmogenic in-situ Carbon-14 (14C) and cosmogenic Beryllium-10 (10Be) as radiotracers. The proposed research emerges from recent studies of cosmogenic in-situ 14C in GISP2 Holocene and several Antarctic ice samples, which revealed marked differences in the 14C concentrations in the samples, compared to the theoretically expected values. The GISP2 samples have about the expected amount of 14C but the Antarctic samples are deficient by 30-50% or more. These results suggest that in slowly accumulating ice samples (such as occur in Antarctica), the cosmic ray implanted 14C is somehow partially lost, but quantitatively preserved in samples from areas of high accumulation. These results suggest that after deposition of the cosmogenic 14C, its concentration is decreased in firn due to processes such as recrystallization, sublimation/evaporation and redeposition. In order to quantify these processes, the atmospheric cosmogenic 10Be in ice samples will also be measured. Since 10Be and 14C have different responses to the firnification processes, their simultaneous study can help to elucidate the nature and importance of these processes. Samples from Taylor Dome, Vostok and Siple Dome will all be studied. | POINT(106.133 -76.083) | POINT(106.133 -76.083) | false | false |