USAP-DC

{"dp_type": "Dataset", "free_text": "Crystals"}

[{"awards": "0632399 Jefferies, Stuart", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "The ultimate goal of this project is to determine the structure and dynamics of the Sun\u0027s atmosphere, assess the role of MHD waves in heating the chromosphere/corona and driving the solar wind, and better understand how the Sun\u0027s atmosphere couples to the solar interior. As the solar atmosphere is \u0027home\u0027 to many of the solar phenomena that can have a direct impact on the biosphere, including flares, coronal mass ejections, and the solar wind, the broader impact of such studies is that they will lead to an improved understanding of the Sun-Earth connection. \nUnder the current award we have developed a suite of instruments that can simultaneously image the line-of-sight Doppler velocity and longitudinal magnetic field at four heights in the solar atmosphere at high temporal cadence. The instruments use magneto-optical filters (see Cacciani, Moretti and Rodgers, Solar Physics 174, p.115, 2004) tuned to the solar absorption lines at 422 nm (Ca I), 589 nm (Na D2), 770 nm (K) and 1083 nm (He). These lines sample the solar atmosphere from the mid-photosphere to the high-chromosphere. \nA proof-of-concept run was made in the Austral summer of 2007/2008 using the Na and K versions of the instruments. Here we recorded over 40 hours of full-disk, intensity images of the Sun in the red and blue wings of the Na and K Fraunhofer lines, in both right- and left-circularly polarized light. The images were obtained at a rate of one every five seconds with a nominal spatial resolution of 4 arc-seconds. The run started at 09:44 UT on February 2, 2008 and ended at 03:30 UT on February 4, 2008.\nData Quality Assessment:\nThe temperature controls of the instrument housings were unable to fully compensate for the harse Antartic winds encountered during the observing run. This led to large (~15 C) temperature swings which adversely affected the instruments (and thus data quality) in two ways: 1) Crystals of Na and K were deposited on the magneto-optical filter windows leading to \"hot spots\" in the images. These \"hot spots\" come and go with time as the temperature changes. 2) The changing temperature caused the optical rails to contract and expand causing the final images to go in- and out-of-focus, thus reducing the resolution to greater than 4 arc-seconds. Both these effect are worse in the K data.\nDespite these problems, the intensity images can be combined to provide magnetic images that show a very high sensitivity (\u003c 5 Gauss in a 5 second integration).\nData Description:\nThe raw data are stored as a series of 1024x1024x4 FITS images. The format is: blue image (left circulary polarized light), blue image (right circularly polarized light), red image (left circulary polarized light), red image (right circularly polarized light).\nThe naming convention for the images is: Type_Instrument_Day_hour_minutes_seconds\nwhere Type is I (intensity), F (flatfield), D (dark)\n Instrument is 0 (Na), 1 (K)\n Day is the day number from the beginning of the year where January 1 is day 0\nFor example, I_0_32_12_34_40.fits is an intensity image taken with the Na instrument at 12:34.40 UT on February 2, 2008.\nNotes: \n1) The flatfield images were acquired by moving a diffuser in front of the Sun during the integration. The resulting images therefore have to be corrected for residual low-spatial frequencies due to the non-flat nature of the light source.\n2) Each FITS file header contains a variety of information on the observation, e.g.,\nF_CNTO\t: number of summed frames in each 5 second integration (*)\nFPS\t\t: Camera frame rate (Frames Per Second)\nFLIP\t: Rate at which the half-wave rotator (magnetic switch) was switched\nINT_PER\t: Integration time (in seconds)\nMOF\t\t: Temperature of magneto-optical filter cell\nWS\t\t: Temperature of wing selector cell\nTEMP_0\t: Temperature of camera 0\nTEMP_1\t: Temperature of camera 1\nTEMP_2\t: Temperature inside instrument (location 1)\nTEMP_3\t: Temperature of narrowband filter\nTEMP_5\t: Temperature of magnets surrounding MOF cell\nTEMP_6\t: Temperature inside instrument (location 2)\nTEMP_7\t: Temperature of housing for magnetic switch\n(*) This is the frame count for the camera. The number of frames in each image for the two different polarization states, is half this number.\nThe measured temperatures are only coarse measurements.\n3) Due to reflection in the final polarizing beam splitter (which separates the \"red\" and \"blue\" signals into the two cameras), the camera 1 data need to \"reversed\" along the x-axis (i.e. listed as [1024:1] instead of [1:1024])\n4) Line-of-sight velocity and magnetic field images are generated from the observed intensity images. Doppler images as (red-blue)/(red+blue), magnetic images as the difference between the Doppler images\nfor right- and left-circularly polarized light.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cosmos; Satellite Remote Sensing; Sun", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": null, "persons": "Jefferies, Stuart M.", "project_titles": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere", "projects": [{"proj_uid": "p0000526", "repository": "USAP-DC", "title": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere", "uid": "600152", "west": -180.0}, {"awards": "1043145 Obbard, Rachel", "bounds_geometry": ["POLYGON((164.1005 -77.1188,164.36443 -77.1188,164.62836 -77.1188,164.89229 -77.1188,165.15622 -77.1188,165.42015 -77.1188,165.68408 -77.1188,165.94801 -77.1188,166.21194 -77.1188,166.47587 -77.1188,166.7398 -77.1188,166.7398 -77.19337,166.7398 -77.26794,166.7398 -77.34251,166.7398 -77.41708,166.7398 -77.49165,166.7398 -77.56622,166.7398 -77.64079,166.7398 -77.71536,166.7398 -77.78993,166.7398 -77.8645,166.47587 -77.8645,166.21194 -77.8645,165.94801 -77.8645,165.68408 -77.8645,165.42015 -77.8645,165.15622 -77.8645,164.89229 -77.8645,164.62836 -77.8645,164.36443 -77.8645,164.1005 -77.8645,164.1005 -77.78993,164.1005 -77.71536,164.1005 -77.64079,164.1005 -77.56622,164.1005 -77.49165,164.1005 -77.41708,164.1005 -77.34251,164.1005 -77.26794,164.1005 -77.19337,164.1005 -77.1188))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "A range of chemical and microphysical pathways in polar latitudes, including spring time (tropospheric) ozone depletion, oxidative pathways for mercury, and cloud condensation nuclei (CCN) production leading to changes in the cloud cover and attendant surface energy budgets, have been invoked as being dependent upon the emission of halogen gases formed in sea-ice.\nThe prospects for climate warming induced reductions in sea ice extent causing alteration of these incompletely known surface-atmospheric feedbacks and interactions requires confirmation of mechanistic details in both laboratory studies and field campaigns. One such mechanistic question is how bromine (BrO and Br) enriched snow migrates or is formed through processes in sea-ice, prior to its subsequent mobilization as an aerosol fraction into the atmosphere by strong winds. Once aloft, it may react with ozone and other atmospheric species. Dartmouth researchers will collect snow from the surface of sea ice, from freely blowing snow and in sea-ice cores from Cape Byrd, Ross Sea. A range of spectroscopic, microanalytic and and microstructural approaches will be subsequently used to determine the Br distribution gradients through sea-ice, in order to shed light on how sea-ice first forms and then releases bromine species into the polar atmospheric boundary layer.", "east": 166.7398, "geometry": ["POINT(165.42015 -77.49165)"], "keywords": "Atmosphere; Chemistry:ice; Chemistry:Ice; Critical Zone; Crystals; Glaciology; Oceans; Photo/video; Photo/Video; Ross Sea; Sea Ice; Sea Surface; Snow; Southern Ocean", "locations": "Ross Sea; Sea Surface; Southern Ocean", "north": -77.1188, "nsf_funding_programs": null, "persons": "Obbard, Rachel", "project_titles": "Bromide in Snow in the Sea Ice Zone", "projects": [{"proj_uid": "p0000414", "repository": "USAP-DC", "title": "Bromide in Snow in the Sea Ice Zone"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8645, "title": "Bromide in Snow in the Sea Ice Zone", "uid": "600158", "west": 164.1005}, {"awards": "0838722 Reiners, Peter", "bounds_geometry": ["POLYGON((61.9 -67.28,63.218 -67.28,64.536 -67.28,65.854 -67.28,67.172 -67.28,68.49 -67.28,69.808 -67.28,71.126 -67.28,72.444 -67.28,73.762 -67.28,75.08 -67.28,75.08 -67.922,75.08 -68.564,75.08 -69.206,75.08 -69.848,75.08 -70.49,75.08 -71.132,75.08 -71.774,75.08 -72.416,75.08 -73.058,75.08 -73.7,73.762 -73.7,72.444 -73.7,71.126 -73.7,69.808 -73.7,68.49 -73.7,67.172 -73.7,65.854 -73.7,64.536 -73.7,63.218 -73.7,61.9 -73.7,61.9 -73.058,61.9 -72.416,61.9 -71.774,61.9 -71.132,61.9 -70.49,61.9 -69.848,61.9 -69.206,61.9 -68.564,61.9 -67.922,61.9 -67.28))"], "date_created": "Sun, 01 Jan 2012 00:00:00 GMT", "description": "Much of the inventory of East Antarctic bedrock geochronology, as well as a record of its erosional history, is preserved in Cenozoic sediments around its margin. This project is to use these sediments to understand their sub-ice provenance and the erosional history of the shield by measuring ages of multiple geo- and thermochronometers on single detrital crystals and on multiple crystals in detrital clasts (U/Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar). The combination of multi-chronometer ages in single grains and clasts provides a powerful fingerprint of bedrock sources, allowing us to trace provenance in Eocene fluvial sandstones through Quaternary diamicts around the margin. Multiple thermochronometric (cooling) ages in the same grains and clasts also allows us to interpret the timing and rates of erosion from these bedrock sources. Delineating a distribution of bedrock age units, their sediment transport connections, and their erosional histories over the Cenozoic, will in turn allow us to test tectonic models bearing on: (1) the origin of the Gamburtsev Subglacial Mountains, (2) fluvial and topographic evolution, and (3) the history of glacial growth and erosion.\n", "east": 75.08, "geometry": ["POINT(68.49 -70.49)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Marine Sediments; NBP0101; ODP1166; ODP739; Prydz Bay; Solid Earth; Southern Ocean", "locations": "Gamburtsev Mountains; Prydz Bay; Antarctica; Southern Ocean", "north": -67.28, "nsf_funding_programs": null, "persons": "Gehrels, George; Reiners, Peter; Thomson, Stuart", "project_titles": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "projects": [{"proj_uid": "p0000506", "repository": "USAP-DC", "title": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -73.7, "title": "Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "uid": "600093", "west": 61.9}, {"awards": "0838729 Hemming, Sidney", "bounds_geometry": ["POLYGON((-67.2 -58,-43.98 -58,-20.76 -58,2.46 -58,25.68 -58,48.9 -58,72.12 -58,95.34 -58,118.56 -58,141.78 -58,165 -58,165 -59.2,165 -60.4,165 -61.6,165 -62.8,165 -64,165 -65.2,165 -66.4,165 -67.6,165 -68.8,165 -70,141.78 -70,118.56 -70,95.34 -70,72.12 -70,48.9 -70,25.68 -70,2.46 -70,-20.76 -70,-43.98 -70,-67.2 -70,-67.2 -68.8,-67.2 -67.6,-67.2 -66.4,-67.2 -65.2,-67.2 -64,-67.2 -62.8,-67.2 -61.6,-67.2 -60.4,-67.2 -59.2,-67.2 -58))"], "date_created": "Sat, 01 Jan 2011 00:00:00 GMT", "description": "Much of the inventory of East Antarctic bedrock geochronology, as well as a record of its erosional history, is preserved in Cenozoic sediments around its margin. This project is to use these sediments to understand their sub-ice provenance and the erosional history of the shield by measuring ages of multiple geo- and thermochronometers on single detrital crystals and on multiple crystals in detrital clasts (U/Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar). The combination of multi-chronometer ages in single grains and clasts provides a powerful fingerprint of bedrock sources, allowing us to trace provenance in Eocene fluvial sandstones through Quaternary diamicts around the margin. Multiple thermochronometric (cooling) ages in the same grains and clasts also allows us to interpret the timing and rates of erosion from these bedrock sources. Delineating a distribution of bedrock age units, their sediment transport connections, and their erosional histories over the Cenozoic, will in turn allow us to test tectonic models bearing on: (1) the origin of the Gamburtsev Subglacial Mountains, (2) fluvial and topographic evolution, and (3) the history of glacial growth and erosion.", "east": 165.0, "geometry": ["POINT(48.9 -64)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Marine Sediments; Solid Earth; Southern Ocean", "locations": "Gamburtsev Mountains; Antarctica; Southern Ocean", "north": -58.0, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "projects": [{"proj_uid": "p0000506", "repository": "USAP-DC", "title": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "uid": "600094", "west": -67.2}, {"awards": "0816934 Thomson, Stuart", "bounds_geometry": ["POLYGON((65 -66,72.9 -66,80.8 -66,88.7 -66,96.6 -66,104.5 -66,112.4 -66,120.3 -66,128.2 -66,136.1 -66,144 -66,144 -66.3,144 -66.6,144 -66.9,144 -67.2,144 -67.5,144 -67.8,144 -68.1,144 -68.4,144 -68.7,144 -69,136.1 -69,128.2 -69,120.3 -69,112.4 -69,104.5 -69,96.6 -69,88.7 -69,80.8 -69,72.9 -69,65 -69,65 -68.7,65 -68.4,65 -68.1,65 -67.8,65 -67.5,65 -67.2,65 -66.9,65 -66.6,65 -66.3,65 -66))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica\u0027s largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow.", "east": 144.0, "geometry": ["POINT(104.5 -67.5)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Solid Earth", "locations": "Gamburtsev Mountains; Antarctica", "north": -66.0, "nsf_funding_programs": null, "persons": "Thomson, Stuart", "project_titles": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "projects": [{"proj_uid": "p0000210", "repository": "USAP-DC", "title": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "uid": "600089", "west": 65.0}, {"awards": "0817163 Reiners, Peter", "bounds_geometry": ["POLYGON((72 -66,72.3 -66,72.6 -66,72.9 -66,73.2 -66,73.5 -66,73.8 -66,74.1 -66,74.4 -66,74.7 -66,75 -66,75 -66.3,75 -66.6,75 -66.9,75 -67.2,75 -67.5,75 -67.8,75 -68.1,75 -68.4,75 -68.7,75 -69,74.7 -69,74.4 -69,74.1 -69,73.8 -69,73.5 -69,73.2 -69,72.9 -69,72.6 -69,72.3 -69,72 -69,72 -68.7,72 -68.4,72 -68.1,72 -67.8,72 -67.5,72 -67.2,72 -66.9,72 -66.6,72 -66.3,72 -66))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica\u0027s largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow.", "east": 75.0, "geometry": ["POINT(73.5 -67.5)"], "keywords": "Antarctica; Gamburtsev Mountains; Geochronology; Marine Sediments; NBP0101; ODP1166; Prydz Bay; Solid Earth; Southern Ocean", "locations": "Gamburtsev Mountains; Prydz Bay; Antarctica; Southern Ocean", "north": -66.0, "nsf_funding_programs": null, "persons": "Gehrels, George; Reiners, Peter", "project_titles": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "projects": [{"proj_uid": "p0000210", "repository": "USAP-DC", "title": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "uid": "600090", "west": 72.0}]

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