Characteristics of modern atmospheric dust deposition in snow on the Penny Ice Cap, Baffin Island, Arctic Canada

We evaluated the concentration, size and distribution of insoluble dust microparticles in snowpits on the Penny Ice Cap (PIC), Baffin Island, to define (1) the characteristics of modern atmospheric dust deposition at the site, (2) the relative contributions of proximal and distal dust sources, and (3) the effects of summer melting on depositional signals in snow. The mean concentration (143 mg kg−1), flux (4.8 mg cm2 yr−1) and diameter (2.3 mm) of dust deposited on the PIC are similar to those observed in remote Arctic sites such as central Greenland, implying that dust is primarily supplied through long-range transport from far-removed source regions (at least 102–103 km distant). There is evidence for two seasonal maxima of dust deposition, one in late winter-early spring and one in late summer-early fall, although seasonal signals can not always be resolved in the snowpack due to some post-depositional particle migration with summer melt. However, ice layers appear to limit the mobility of particles, thereby preserving valuable paleoclimatic information in the PIC ice core dust record at a multi-annual to decadal temporal resolution

The Statement of Cash Flows - Unresolved Issues

Financial Accounting Standards no. 95, the Statement of Cash Flows, was released to enhance the comparability and usefulness of the Statement of Cash Flows. Overall, the new guidelines (under Financial Accounting Standards no. 95) on preparing the Statement of Cash Flows have solved many problems that have been disputed int he past, however comparability and usefulness still remain to be a significant concern among financial statement users. Specifically, classification of several items, the direct and indirect methods of reporting cash flow from operations, and noncash transaction disclosures are three of the most significant unresolved issues that must be addressed. Proposed recommendations of improvement include: 1) A new statement called a Statement of Income and Cash Flows, 2) a standardized noncash disclosure note, and 3) mandated use of the direct method of reporting cash flows from operations.B.S. (Bachelor of Science

Collaborative Research: A 700-Year Tephrochronology of the Law Dome Ice Core, East Antarctica

This award supports a project to analyze samples from the Law Dome ice core for volcanic tephra. The Law Dome ice core is the best-dated ice core from East Antarctica and contains a detailed record of climate and atmospheric chemistry over at least the last 700 years. Several global volcanic eruptions appear to be recorded in the Law Dome core, including the well known Tambora 1815 and Unknown 1809 events, as well as the Huaynaputina 1600 and Ruiz 1595 events. To verify the source eruptions responsible for these signals, as well as to differentiate between local Antarctic and southern hemisphere eruptions, a continuous scan for volcanic glass at an annual resolution will be done on the last 700 years of the Law Dome ice core. Sub-annual tephra analyses will be done in the sections containing the largest acid signals in the core. To better evaluate the climatic impact of large equatorial eruptions from ice cores, it is necessary to isolate local eruptions and their associated glaciochemical signal from that of these more distant sources. The identification of local eruptions in the Law Dome core will improve upon the existing chronology of Antarctic volcanism over the last 700 years through the presence of volcanic glass in conjunction with the results from this same type of study on the Siple Dome ice core

Collaborative Research: Volcanic Records from the Siple and Taylor Dome Ice Cores, Antarctica

The primary goals of this project were to, 1) evaluate the volcanic acidity record in the Siple Dome A (SDMA) and B (SDMB) ice cores and the Taylor Dome ice core available through the sulfate time series developed by the glaciochemistry group at the University of Maine, 2) undertake a continuous scan of the SDMA core and scan specific sections in the SDMB core to locate and analyze volcanic glass to determine glass composition, and thus source eruptions for the glass and potentially for volcanic sulfate found in the same layer, and 3) evaluate specific sections containing volcanic glass in the Taylor Dome ice core as noted by visible layers in that core. A specific use of these volcanic records is to identify products of known volcanic eruptions, where possible, thereby providing distinct time lines that are used in developing the depth-age scale for the individual ice cores. In addition, the evaluation of volcanic glass can help differentiate signals that originated from local (Antarctica) volcanic eruptions and those originating from mid-latitude southern hemisphere or equatorial eruptions

Highly Detailed Reconstructions of New England Weather over the Past Few Centuries and Their Climatic Implications

This award will enable researchers to reconstruct daily weather conditions for New England over the past 300 years by compiling and analyzing written archives such as diaries, journals, agricultural records, and marine logs. These archives will be used to reconstruct daily weather maps that will be compared with recent climatic conditions. New England has a large number of lengthy weather archives and is a region sensitive to changing climatic conditions. The region is influenced by storm tracks and upper-air disturbances that impact the Canadian High, Icelandic Low and the Bermuda-Azores High from year-to-year.Obtaining highly detailed and lengthy records of past climatic variability at the regional scale is important to better inform society about the range of climatic change in the lives of individuals. It is also important to develop records of past climatic conditions with daily resolution to evaluate how the number and magnitude of extreme climatic events (i.e., nor\u27Easters, hurricanes, tornadoes, and ice storms) have changed with time. It is these extreme events that can greatly affect individuals and communities.The use of the 300-year record from New England and the reconstruction of synoptic conditions helps to infer differences in seasonality between cold years, warm years, and more common (i.e., normal) years during the Little Ice Age. Instrumental records over approximately the last 100 years provide time series for the evaluation of recent changes that may be representative of anthropogenically-induced conditions. Daily weather conditions will be compiled in electronic format and placed on the World Wide Web. These data will be available to the general public, including schools, to use when evaluating changes in climate

Depletion of atmospheric nitrate and chloride as a consequence of the Toba Volcanic Eruption

Continuous measurements of SO42− and electrical conductivity (ECM) along the GISP2 ice core record the Toba mega‐eruption at a depth 2590.95 to 2091.25 m (71,000±5000 years ago). Major chemical species were analyzed at a resolution of 1 cm per sample for this section. An ∼6‐year long period with extremely high volcanic SO42− coincident with a 94% depletion of nitrate and 63% depletion of chloride is observed at the depth of the Toba horizon. Such a reduction of chloride in a volcanic layer preserved in an ice core has not been observed in any previous studies. The nearly complete depletion of nitrate (to 5 ppb) encountered at the Toba level is the lowest value in the entire ∼250,000 years of the GISP2 ice core record. We propose possible mechanisms to explain the depletion of nitrate and chloride resulting from this mega‐eruption