Dr. Michael Ram
Professor Emeritus, Ph.D. Columbia (1965)
Office: 303 Fronczak Hall, (716) 645-5903
Lab: 340 Fronczak Hall, (716) 645-6252
link to personal website for more info
Ph.D. -- Columbia University (1965)
M.S. -- Technion, Israel (1962)
B.S. -- Technion, Israel (1960)
- Measurements and analysis of solar cycle modulations in the GISP2 ice core dust profile
- Analysis of evidence of severe dust storms seen in ice age Greenland ice
My research efforts in recent years have mainly been involved in
getting information on past climates and climate change. As a
principle investigator in the National Science Foundation's Greenland
Ice Sheet Project 2 (GISP2) initiative, I developed laser-light
scattering (LLS) techniques to measure the dust profile along the
length of the 3000plus-meters-long GISP2 ice core that was retrieved
from central Greenland. Since the dust in the ice is believed to be
representative of past atmospheric dust burdens, our measurements
reflect how past atmospheric dust burdens changed over the past
100,000-plus years. This information is of critical importance in
climate modeling since atmospheric dust can absorb and scatter
solar energy, and can thus modify the earth's albedo. Since it is
known that dust concentration in the core varies seasonally with
maxima occurring every spring/summer, our work has been of critical
importance in dating the GISP2 ice core. In addition, our work is
yielding important information on violent dust storms that seem to
have been prevalent during cold glacial times. Also, we observed that
the dust concentration along the ice core was modulated with 11-, 20-,
90-, and 200-year periods, which we attribute to the solar cycle.
These modulations occur throughout the core, and we observe them
all the way back to 100,000 years BP. We have suggested that the
dust modulations are a consequence of solar modulation of the
terrestrial cosmic ray flux, which can influence cloud cover.
FIG. 1 Dust profile of GISP2 ice core observed using laser-
light scattering (LLS) from ice. For comparison, we also show the
oxygen isotope profile. Colder periods, corresponding to more
negative oxygen isotope ratios, go hand-in-hand with periods of
higher dust concentration, which is consistent with the idea that the
weather was significantly stormier during the colder periods of the last
- "Possible solar influences on the dust profile of the GISP2 ice core from central Greenland", M. Ram, with M. Stolz, Geophys. Res. Lett. 26(8), 1043-46 (1999).
- "Continuous dust concentration profile of pre-Holocene ice from the GISP2 ice core: Dust stadials, interstadials, and the Eemian", M. Ram, with G. Koenig, Jour. Geophys. Res., special GISP2/GRIP issue 102 C12, 26 641-8 (1997).
- "Eleven-year cycle of dust concentration variability observed in the dust profile of the GISP2 ice core from central Greenland: Possible solar cycle connection", M. Ram, with M. Stolz and G. Koenig, Geophys. Res. Lett. 24 19, 2359-62 (1997).
- "Volcanic ash from Icelandic ~57,300 year BP eruption found in GISP2 (Greenland) ice core", M. Ram, with J. Donarummo and M. Sheridan, Geophys. Res. Lett. 23 22, 3167-9 (1996).
- "Insoluble particles in polar ice: Identification and measurement of the insoluble background aerosol", M. Ram, with R. I. Gayley, Geophys. Res. Lett. 21 6, 437-40 (1994).