Possible solar influences on the dust profile of the GISP2 ice core from

• Main Authors: Michael Ram, Michael R. Stolz
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Greenland; Hale; Greenland Ice Sheet Project; ice core; Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.380.8184; http://www.leif.org/EOS/1999GL900199.pdf

Abstract. The Greenland Ice Sheet Project 2 (GISP2) ice core In this paper, we report and discuss the second finding and dust profile in glacial (Wisconsinan) ice from Cemral Green- demonstrate how a 22 year (Hale) dust modulation period is land has been measured using Laser-Light Scattering (LLS) generated when two consecutive 11 year periods combine in a from ice. This data exhibits considerable high frequency very unique way reminiscent of the generation of a 22 year variability. By applying apprOPriate running averages to the period in the terrestrial neutron flux (Jokipii, 1991). data, certain regularities emerge. Thus, for example, when the data was smoothed with rectangular 4 and 5 year running averages, ~ 11 year dust modulations of considerable amplitude Regularities in the GISP2 Dust Profile were revealed. In this paper, we show how further smoothing of the data causes very large, longer period dust modulations The most prominem and consistera regularity in our GISP2 centered at ~91 years in a Gaussian distribution to emerge. We dust profile is the annual spring dust peaks which have been believe that this corresponds to the 80-90 year modulation of used to date the ice core with a high degree of accuracy (Ram the 11 year sunspot cycle first suggested by Gleissberg. We and Illing, 1994; Ram et al, 1995; Ram and Koenig, 1997; also show how adjacem 11 year dust periods can combine in a Meese et al., 1997). This may be viewed as a solar effect unique way to generate a 22 year (Hale) period of dust modula- inasmuch as it is the result of insolation changes at differera