Debra Meese

Debra Meese
Colorado Mountain College · Math and Science

PhD, OD

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68
Publications
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Publications

Publications (68)
Article
Full-text available
An in-depth analysis of seven samples from the Siple Dome (Antarctica) ice core, using optical microscopy and electron backscatter diffraction, illustrates rotational recrystallization or polygonization in the fine-grained region of the core between 700 and 800 m. Between 640 and 700 m, the microstructure is characterized by a bimodal grain-size di...
Article
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The microstructures and microchemistry of four US International trans-antarctic scientific expedition ice cores were examined, at three depths (30, 60, 90 m) each, using scanning electron microscopy, including electron backscattered patterns and energy-dispersive spectroscopy (eds), in order to assess the relationship between chemical and physical...
Article
Full-text available
The Wisconsin section of the Siple Dome (Antarctica) ice core contains zones where mean crystal size and fabric change suddenly. One of these, at 675 m (15 ka) is coincident with evidence of abrupt climate change. Another, at 726 m (22 ka), may reflect a climate event, however, is more likely due to physical processes. In contrast to the larger cry...
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Firn microstructure is accurately characterized using images obtained from scanning electron microscopy (SEM). Visibly etched grain boundaries within images are used to create a skeleton outline of the microstructure. A pixel-counting utility is applied to the outline to determine grain area. Firn grain sizes calculated using the technique describe...
Article
The quality of the ice core from Siple Dome, West Antarctica, varied widely, with significant fracturing below 400 m. Bubbly ice persisted to the ice-rock interface at 1004 m and constituted the brittle zone. The core has undergone minimal relaxation and has remained brittle and prone to fracturing more than 5 years after it was drilled. This behav...
Article
Approximately 300 volcanic ash and dust layers were observed in the Siple Dome (Antarctica) ice core. Most of this tephra, deposited between 700 and 800 m depth, consisted primarily of glass shards with varying amounts of crystalline material and groundmass fragments. The pattern of distribution of tephra fallout closely replicates that found in th...
Article
In this paper, we use a scanning electron microscope (SEM) coupled with X-ray spectroscopy and electron back-scattered diffraction patterns to examine firn in cores retrieved by the United States International Trans-Antarctic Scientific Expedition. From grain boundary grooves we were able to see where the previously existing snow crystals were join...
Article
Full-text available
Shallow ice cores were obtained from widely distributed sites across the West Antarctic ice sheet, as part of the United States portion of the International Trans-Antarctic Scientific Expedition (US ITASE) program. The US ITASE cores have been dated by annual-layer counting, primarily through the identification of summer peaks in non-sea-salt sulfa...
Article
Results of analyses of snow annual accumulation variability, density and crystal growth measurements in firn and ice cores recovered from the upper layers of the West Antarctic ice sheet during the US component of the International Trans-Antarctic Scientific Expedition (ITASE) are presented. Annual-layer structure was analyzed on the basis of the v...
Article
The Holocene portion of the Siple Dome (Antarctica) ice core was dated by interpreting the electrical, visual and chemical properties of the core. The data were interpreted manually and with a computer algorithm. The algorithm interpretation was adjusted to be consistent with atmospheric methane stratigraphic ties to the GISP2 (Greenland Ice Sheet...
Article
A new ice core from Siple Dome, Antarctica suggests the surface temperature increased by ∼6°C in just several decades at approximately 22 ka BP. This abrupt change did not occur 500 km away in the Byrd ice core, or in climate proxy records in the Siple Dome core indicative of the mid-latitude Pacific. This demonstrates there was significant spatial...
Article
Through the NSF-funded Teachers Experiencing Antarctica and the Arctic (TEA) Program K-12 science teachers participate as members of polar field projects. Objectives of the program include: immersing the science teacher in the experience of research; 2) leveraging the research experience of the teacher to better inform teaching practices; and 3) sh...
Article
Full-text available
Abstract Clustering of cloud microphysical conditions, such as liquid water content (LWC) and drop size, can affect the rate and shape of ice accretion and the airworthiness of aircraft. Clustering may also degrade the accuracy of cloud LWC measurements from radars and microwave radiometers being developed by the government for remotely mapping ici...
Article
Sporadic deposition of volcanic ash in ice cores from Siple Dome, West Antarctica, was first observed at around 500 m and continued to a depth of 650 m before the onset of a major period of ash and dust fallout beginning at around 675 m and picking up substantially at around 700 m. Peak fallout was observed at 707-713 m with additional pulses down...
Article
Sea ice characteristics were investigated during July and August on the 1994 transect across the Arctic Ocean. Properties examined from ice cores included salinity, temperature, and ice structure. Salinities measured near zero at the surface, increasing to 3-40/00 at the ice-water interface. Ice crystal texture was dominated by columnar ice, compri...
Article
Episodes of glaciation in the region north of Baffin Bay resulted in the erosion of Paleozoic carbonate outcrops in NW Greenland and the Canadian High Arctic. These events are recognized in the marine sediments of Baffin Bay (BB) as a series of detrital carbonate-rich (DC-) layers. BBDC-layers thin southward within Baffin Bay; thus, the contributio...
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The Nd, Sr and Pb isotopic compositions of silt particles from the basal silty ice of the two deep ice cores in Central Greenland, GISP 2 and GRIP, are compared to those of the subglacial rock material at GISP 2 (dolerite boulder, till and granitic bedrock). The silt particles embedded in the GRIP basal ice result from the reworking of the subglaci...
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The Greenland Ice Sheet Project 2 (GISP2) depth-age scale is presented based on a multiparameter continuous count approach, to a depth of 2800 m, using a systematic combination of parameters that have never been used to this extent before. The ice at 2800 m is dated at 110,000 years B.P. with an estimated error ranging from 1 to 10% in the top 2500...
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The 110,000-year record of ammonium concentrations from the Greenland Ice Sheet Project 2 (GISP2) ice core provides the basis for an analysis of terrestrial biological production and atmospheric circulation patterns involved in the transport of biologically produced ammonium to the Greenland atmosphere. The directly measured concentration series wa...
Article
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Analysis of ice from Dye-3, Greenland, has demonstrated that the transition between the Younger Dryas and Holocene climate periods occurred over a 40-year period. A near annually resolved, multiparameter record of the transition recorded in the GISP2 core from Summit, Greenland, shows that most of the transition occurred in a series of steps with d...
Article
Annual layers are visible in the Greenland Ice Sheet Project 2 ice core from central Greenland, allowing rapid dating of the core. Changes in bubble and grain structure caused by near-surface, primarily summertime formation of hoar complexes provide the main visible annual marker in the Holocene, and changes in "cloudiness" of the ice correlated wi...
Article
Substantial data sets have been collected on the relaxation characteristics, density, grain size, c axis fabrics, and ultrasonic velocities of the Greenland Ice Sheet Project 2 (GISP2) core to its contact with bedrock at 3053.4 m. Changes in all these properties paralleled closely those found in cores from Byrd Station, Antarctica, and Die 3, Green...
Article
Flow disturbances have been shown to alter stratigraphic order in the lower part of the ice sheet in central Greenland. Vertical thin sections of the Greenland Ice Sheet Project 2 ice core show that in the lower 30%, the expected c axis-vertical fabric is interrupted by planes of grains ("stripes") with c axes oriented approximately in the dip dire...
Article
Full-text available
Successful core-drilling to bedrock of both the Greenland and Antarctic ice sheets offers unique opportunities for examining processes acting at the bed. At Byrd Station, Antarctica, penetration of the bed was accompanied by upwelling of glacial meltwater into the drillhole. The nature and disposition of sediment in the 4.83m thick debris-rich basa...
Article
Successful core-drilling to bedrock of both the Greenland and Antarctic ice sheets offers unique opportunities for examining processes acting at the bed. At Byrd Station, Antarctica, penetration of the bed was accompanied by upwelling of glacial meltwater into the drillhole. The nature and disposition of sediment in the 4.83 m thick debris-rich bas...
Article
Full-text available
Glaciochemical time series developed from Summit, Greenland, indicate that the chemical composition of the atmosphere was dynamic during the Holocene epoch. Concentrations of sea salt and terrestrial dusts increased in Summit snow during the periods 0 to 600, 2400 to 3100, 5000 to 6100, 7800 to 8800, and more than 11,300 years ago. The most recent...
Article
Two technical comments are presented on an article by Zielinski concerning the GISP ice core record of volcanic activity in 7000 BC, including a detailed record of the volcanic contribution to sulfate concentrations. The authors describe concerns about (1) correct C14 dating for known eruptions correlated to calendar years and (2) the need for unam...
Article
Mapping the spatial distribution of c-axis orientations in ice thin sections is not much more difficult than preparing c-axis scatter plots but can reveal additional information about procesess responsible for the observed fabric and texture of the ice. Distributions of angles between c-axes of neighbouring grains from the Byrd Station (West Antarc...
Article
Net accumulation rates at the Greenland summit have been inferred using layer-thickness data from the GISP2 ice core with corrections for strain using a non-linear, one-dimensional flow model of an ice sheet. The flow model accounts for thickness changes in ice-sheet in response to mass-balance variations. The model is used to investigate how net a...
Article
The depth–age relation observed in the GISP2 ice core is the result of the integrated effects of ice-sheet changes over time, as well as the accumulation-rate history. Here, we construct a forward model to compute ages at various depths in the core. In the model, these ages are functions of parameters that describe the ice thickness as a function o...
Article
Mapping the spatial distribution of c-axis orientations in ice thin sections is not much more difficult than preparing c-axis scatter plots but can reveal additional information about processes responsible for the observed fabric and texture of the ice. Distributions of angles between c axes of neighboring grains from the Byrd Station (West Antarct...
Article
Net accumulation rates at the Greenland summit have been inferred using layer-thickness data from the GISP2 ice core with corrections for strain using a non-linear, one-dimensional flow model of an ice sheet. The flow model accounts for thickness changes in ice-sheet in response to mass-balance variations. The model is used to investigate how net a...
Article
The depth–age relation observed in the GISP2 ice core is the result of the integrated effects of ice-sheet changes over time, as well as the accumulation-rate history. Here, we construct a forward model to compute ages at various depths in the core. In the model, these ages are functions of parameters that describe the ice thickness as a function o...
Article
A depth-age scale and an accumulation history for the Holocene have been established on the Greenland Ice Sheet Project 2 (GISP2) deep core, providing the most continuously dated record of annual layer accumulation currently available. The depth-age scale was obtained with the use of various independent techniques to count annual layers in the core...
Article
Full-text available
THE ice cores recovered from central Greenland by the GRIP1,2 and GISP23 projects record 22 interstadial (warm) events during the part of the last glaciation spanning 20-105 kyr before present. The ice core from Vostok, east Antarctica, records nine interstadials during this period4,5. Here we explore links between Greenland and Antarctic climate d...
Article
Sulfate concentrations from continuous biyearly sampling of the GISP2 Greenland ice core provide a record of potential climate-forcing volcanism since 7000 B.C. Although 85 percent of the events recorded over the last 2000 years were matched to documented volcanic eruptions, only about 30 percent of the events from 1 to 7000 B.C. were matched to su...
Article
High-resolution, continuous multivariate chemical records from a central Greenland ice core provide a sensitive measure of climate change and chemical composition of the atmosphere over the last 41,000 years. These chemical series reveal a record of change in the relative size and intensity of the circulation system that transported air masses to G...
Article
Full-text available
On July 1, 1993, after 5 years of drilling, the Greenland Ice Sheet Project (GISP2) penetrated several meters of silty ice and reached bedrock at a depth of 3053.4 m. It then penetrated 1.5 m into the bedrock, producing the deepest ice core ever recovered (Figure 1). In July 1992, a nearby European ice coring effort, the Greenland Ice Core Project...
Article
Full-text available
c -axis fabrics of the GISP2 ice core from central Greenland have been measured rapidly and accurately in the field, using both compressional and shear waves generated by an inexpensive, commercially available, “idiot-proof” device. Compressional-wave data were collected at 10 m intervals for the upper 2250 m of the ice sheet and show progressive c...
Article
c-axis fabrics of the GISP2 ice core from central Greenland have been measured rapidly and accurately in the field, using both compressional and shear waves generated by an inexpensive, commercially available, “idiot-proof” device. Compressional-wave data were collected at 10 m intervals for the upper 2250 m of the ice sheet and show progressive cl...
Article
Full-text available
The last millenium of Earth history is of particular interest because it documents the environmental complexities of both natural variability and anthropogenic activity. We have analyzed the major ions contained in the Greenland Ice Sheet Project 2 ice core from the present to about 674 A.D. to yield an environmental reconstruction for this period...
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THE warming at the end of the last glaciation was characterized by a series of abrupt returns to glacial climate, the best-known of which is the Younger Dryas event1. Despite much study of the causes of this event and the mechanisms by which it ended, many questions remain unresolved1. Oxygen isotope data from Greenland ice cores2-4 suggest that th...
Article
The last millenium of Earth history is of particular interest because it documents the environmental complexities of both natural variability and anthropogenic activity. The authors have analyzed the major ions contained in the Greenland Ice Sheet Project 2 (GISP 2) ice core from the present to â¼674 A.D. to yield an environmental reconstruction fo...
Article
Full-text available
Data for this report were obtained during the Winter Weddell Gyre Study-'89 from the Soviet icebreaker Akademik Fedorov. This study took place between September and November 1989 in the Weddell Sea, Antarctica. Several times each day throughout the cruise, we took notes on the ice conditions that the ship was passing through at that time. These not...
Article
Winter leads are regions of intense ice growth with resultant large fluxes of heat to the atmosphere and salt to the ocean. They constitute a major source of new ice in the Arctic basin. During the 1988 drift phase of the Coordinated Eastern Arctic Experiment we were afforded a unique opportunity to conduct a detailed, long-term study of a freezing...
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Full-text available
The Transantarctic Mountains of East Antarctica provide a new milieu for retrieval of ice-core records. We report here on the initial findings from the first of these records, the Dominion Range ice-core record. Sites such as the Dominion Range are valuable for the recovery of records detailing climate change, volcanic activity, and changes in the...
Article
The Transantarctic Mountains of East Antarctica provide a new milieu for retrieval of ice-core records. We report here on the initial findings from the first of these records, the Dominion Range ice-core record. Sites such as the Dominion Range are valuable for the recovery of records detailing climate change, volcanic activity, and changes in the...
Article
Full-text available
Thesis (Ph. D.)--University of New Hampshire, 1988. Includes bibliographical references (p. 212-214). Microfiche. s
Article
The purpose of this study was to provide general information on the chemical, physical and structural properties of estuarine ice and show how it compares with sea ice found at higher latitudes in order to determine whether the ice in Great Bay can be used as an analog in the study of arctic sea ice.Ice cores and water samples were collected during...
Article
Scientists involved in the NSF-funded Teachers Experiencing Antarctica and the Arctic (TEA) Program integrate a K-12 science teacher into their polar field project. Objectives of the program include: having the science teacher immersed in the experience of research; 2) through the teacher, leveraging the research experience to better inform teachin...
Article
We use a ~98ky glaciochemical record recovered from Siple Dome that was collected as part of the WAIS Initiative to understand West Antarctic climate variability. This glaciochemical record reveals strong source signals from the ocean (seasalt (ssNa, ssK, ssMg, ssCa, ssCl, ss-sulfate) and biogenic non-ss-sulfate), volcanism (excess-sulfate), remote...
Article
Nine cores have thus far been analyzed in detail from across West Antarctica as part of the U.S. International Trans-Antarctic Scientific Experiment (ITASE). Accumulation rates vary greatly in the cores based on elevation, temperature, location, etc. Mean annul layer thickness, densification rate, melt layers and crusts will be discussed for each c...
Article
Results of analyses of density and crystal growth measurements in firn and ice cores recovered from the upper layers of the West Antarctic Ice Sheet during the US component of the International Trans-Antarctic Scientific Expedition (ITASE) are presented. Density profiles were measured in the field on meter-long cores; all profiles except one exhibi...
Article
Full-text available
For many years, the microstructural characterization of ice and firn has used optical microscopy often involving observation of thin sections between crossed polarizers. However, such an approach, in addition to being of low resolution, does not provide complete information on the microstructure. In previous work (Obbard et al. 2003), we have shown...
Article
Thesis (M.S.)--University of New Hampshire, 1985. Includes bibliographical references (leaves [89]-92).

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