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Full-Text Articles in Physical Sciences and Mathematics

Assessment Of The Record Of The 1982 El Chichón Eruption As Preserved In Greenland Snow, Gregory A. Zielinski, Jack E. Dibb, Qinzhao Yang, Paul Andrew Mayewski, Sallie Whitlow, Mark S. Twickler, Mark S. Germani Dec 1997

Assessment Of The Record Of The 1982 El Chichón Eruption As Preserved In Greenland Snow, Gregory A. Zielinski, Jack E. Dibb, Qinzhao Yang, Paul Andrew Mayewski, Sallie Whitlow, Mark S. Twickler, Mark S. Germani

Earth Science Faculty Scholarship

Variability in the SO 4 2 - and Cl time series for the 1980s from 12 shallow snow pits across the Greenland ice sheet is used to evaluate the record of the 1982 El Chichón eruption and the potential for recording a moderate northern equatorial eruption in a single Greenland ice core. Composition of volcanic glass found in spring 1983 snow in one of the pits in the Summit region matches that from El Chichón glass, thereby verifying the deposition of material from the eruption. High Na+ and Cl concentrations in this same layer probably represent deposition …


A 110,000-Year History Of Change In Continental Biogenic Emissions And Related Atmospheric Circulation Inferred From The Greenland Ice Sheet Project Ice Core, L. D. Meeker, Paul Andrew Mayewski, M. S. Twickler, S. I. Whitlow, D. Meese Nov 1997

A 110,000-Year History Of Change In Continental Biogenic Emissions And Related Atmospheric Circulation Inferred From The Greenland Ice Sheet Project Ice Core, L. D. Meeker, Paul Andrew Mayewski, M. S. Twickler, S. I. Whitlow, D. Meese

Earth Science Faculty Scholarship

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 was selected for analysis, rather than that of estimated ammonium flux, after a detailed analysis of the relationship among ice core glaciochemical concentrations and a high-resolution simultaneous record of snow accumulation from the GISP2 core. Analysis of the ammonium concentration series shows that maxima in background levels of ammonium in the Greenland atmosphere …


The Co2 Concentration Of Air Trapped In Greenland Ice Sheet Project 2 Ice Formed During Periods Of Rapid Climate Change, H. J. Smith, M. Wahlen, D. Mastroianni, K. Taylor, Paul Andrew Mayewski Nov 1997

The Co2 Concentration Of Air Trapped In Greenland Ice Sheet Project 2 Ice Formed During Periods Of Rapid Climate Change, H. J. Smith, M. Wahlen, D. Mastroianni, K. Taylor, Paul Andrew Mayewski

Earth Science Faculty Scholarship

The CO2 content of air occluded in Greenland Ice Sheet Project 2 (GISP2) ice formed over two separate intervals of rapidly changing climate, centered at approximately 46 and 63 kyr B. P., is as much as 90 ppm more during warm periods (interstadials) than during cold periods (stadials). These CO2 variations are superimposed on changes in annual layer thickness and δ18O of the ice and do not show the 200- to 700-year offsets which would be expected for concurrent variations in the atmosphere and the ice. The CO2 concentrations during the stadials are similar to …


Electrical Measurements On The Greenland Ice Sheet Project 2 Core, Kendrick C. Taylor, Richard B. Alley, Gregg W. Lamorey, Paul Andrew Mayewski Nov 1997

Electrical Measurements On The Greenland Ice Sheet Project 2 Core, Kendrick C. Taylor, Richard B. Alley, Gregg W. Lamorey, Paul Andrew Mayewski

Earth Science Faculty Scholarship

The Greenland Ice Sheet Project 2 (GISP2) electrical conductivity measurement (ECM) record is an indication of the concentration of H+ in the core. The ECM detected seasonal variations in the nitrate concentration of the core which were used to assist in dating the core by annual layer counting. Volcanic eruptions that produce acidic aerosols are recorded in the ECM record. Evidence of biomass burning is detected by the ECM because fire-related ammonium emissions neutralize the acids in the core. Rapid climate transitions associated with the Younger Dryas and Dansgaard/Oeschger interstadial events alter the concentration of alkaline dust and are detected …


Paleoclimatic Variability Inferred From The Spectral Analysis Of Greenland And Antarctic Ice-Core Data, R. Yiou, K. Fuher, L. D. Meeker, J. Jouzel, S. Johnsen, Paul Andrew Mayewski Nov 1997

Paleoclimatic Variability Inferred From The Spectral Analysis Of Greenland And Antarctic Ice-Core Data, R. Yiou, K. Fuher, L. D. Meeker, J. Jouzel, S. Johnsen, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Paleoclimate variations occur at various time scales, between a few centuries for the Heinrich events and several hundreds of millenia for the glacial to interglacial variations. The recent ice cores from Greenland (Greenland Ice Core Project and Greenland Ice Sheet Project 2) and Antarctica (Vostok) span at least one glacial oscillation and provide many opportunities to investigate climate variations with a very fine resolution. The joint study of cores from both hemispheres allows us to distinguish between the sources of variability and helps to propose mechanisms of variations for the different time scales involved. The climate proxies we analyze are …


The Greenland Ice Sheet Project 2 Depth-Age Scale: Methods And Results, D. A. Meese, A. J. Gow, R. B. Alley, G. A. Zielinski, P. M. Grootes, M. Ram, K. C. Taylor, Paul Andrew Mayewski, J. F. Bolzan Nov 1997

The Greenland Ice Sheet Project 2 Depth-Age Scale: Methods And Results, D. A. Meese, A. J. Gow, R. B. Alley, G. A. Zielinski, P. M. Grootes, M. Ram, K. C. Taylor, Paul Andrew Mayewski, J. F. Bolzan

Earth Science Faculty Scholarship

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 m of the core and averaging 20% between 2500 and 2800 m. Parameters used to date the core include visual stratigraphy, oxygen isotopic ratios of the ice, electrical conductivity measurements, laser-light scattering from dust, volcanic signals, and …


Volcanic Aerosol Records And Tephrochronology Of The Summit, Greenland, Ice Cores, Gregory A. Zielinski, Paul Andrew Mayewski, L. David Meeker, Karl Grönvold, Mark D. Germani, Sallie Whitlow, Mark S. Twickler, Kendrick Taylor Nov 1997

Volcanic Aerosol Records And Tephrochronology Of The Summit, Greenland, Ice Cores, Gregory A. Zielinski, Paul Andrew Mayewski, L. David Meeker, Karl Grönvold, Mark D. Germani, Sallie Whitlow, Mark S. Twickler, Kendrick Taylor

Earth Science Faculty Scholarship

The recently collected Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice Core Project ice cores from Summit, Greenland, provide lengthy and highly resolved records of the deposition of both the aerosol (H2SO4) and silicate (tephra) components of past volcanism. Both types of data are very beneficial in developing the hemispheric to global chronology of explosive volcanism and evaluating the entire volcanism-climate system. The continuous time series of volcanic SO42− for the last 110,000 years show a strong relationship between periods of increased volcanism and periods of climatic change. The greatest number of volcanic …


Major Features And Forcing Of High-Atitude Northern Hemisphere Atmospheric Circulation Using A 110,000-Year-Long Glaciochemical Series, Paul Andrew Mayewski, Loren D. Meeker, Mark S. Twickler, Sallie Whitlow, Qinzhao Yang, W. Berry Lyons, Michael Prentice Nov 1997

Major Features And Forcing Of High-Atitude Northern Hemisphere Atmospheric Circulation Using A 110,000-Year-Long Glaciochemical Series, Paul Andrew Mayewski, Loren D. Meeker, Mark S. Twickler, Sallie Whitlow, Qinzhao Yang, W. Berry Lyons, Michael Prentice

Earth Science Faculty Scholarship

The Greenland Ice Sheet Project 2 glaciochemical series (sodium, potassium, ammonium, calcium, magnesium, sulfate, nitrate, and chloride) provides a unique view of the chemistry of the atmosphere and the history of atmospheric circulation over both the high latitudes and mid-low latitudes of the northern hemisphere. Interpretation of this record reveals a diverse array of environmental signatures that include the documentation of anthropogenically derived pollutants, volcanic and biomass burning events, storminess over marine surfaces, continental aridity and biogenic source strength plus information related to the controls on both high- and low-frequency climate events of the last 110,000 years. Climate forcings investigated …


Methanesulfonate In The Greenland Ice Sheet Project 2 Ice Core, E. S. Saltzman, P-Y. Whung, Paul Andrew Mayewski Nov 1997

Methanesulfonate In The Greenland Ice Sheet Project 2 Ice Core, E. S. Saltzman, P-Y. Whung, Paul Andrew Mayewski

Earth Science Faculty Scholarship

In this paper we present measurements of methanesulfonate in the Greenland Ice Sheet Project 2 (GISP2) ice core. Methanesulfonate is an atmospheric oxidation product of dimethylsulfide. The GISP2 methanesulfonate record contains information about the atmospheric loading of biogenic sulfur over the past 110 kyr and its relationship to climate change. The GISP2 data set supports the inferences made from the Renland ice core from Greenland that the glacial atmosphere over Greenland had reduced concentrations of biogenic sulfur compared with the present day [Hansson and Saltzman, 1993]. We conclude that the flux of biogenic sulfur from the North Atlantic Ocean …


Glaciochemistry Of Polar Ice Cores: A Review, Michel Legrand, Paul Andrew Mayewski Aug 1997

Glaciochemistry Of Polar Ice Cores: A Review, Michel Legrand, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Human activities have already modified the chemical composition of the natural atmosphere even in very remote regions of the world. The study of chemical parameters stored in solid precipitation and accumulated on polar ice sheets over the last several hundred thousand years provides a unique tool for obtaining information on the composition of the preindustrial atmosphere and its natural variability over the past. This paper deals with the chemistry of polar ice focused on the soluble mineral (Na+, NH4+, K+, Ca++, Mg++, H+, F, Cl …