Search

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 such events. Several historic eruptions may have been greater sulfur producers than previously thought. There are three times as many events from 5000 to 7000 B.C. as over the last two millennia with sulfate deposition equal to or up to five times that of the largest known historical eruptions. This increased volcanism in the early Holocene may have contributed to climatic cooling., Volcanic aerosols have an important role in the Earth's climate, beginning with their contribution to the development of the primordial atmosphere (1). More recently, much interest has focused on the [...]

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 durations of about 5 years. Some climate proxies associated with mid-latitude sources appear to have changed about 15 years before climate proxies associated with more northern regions. Changes in atmospheric water vapor are likely to have played a large role in the climate transition., The Greenland Ice Sheet Project II (GISP2) and Greenland Ice Core Project (GRIP) ice cores were collected at the summit of the Greenland ice sheet at locations selected to obtain [...]

The results of the Greenland ice core GISP2 showing that snow accumulated within one to three years from the Younger Dryas event to the subsequent Preboreal interval is reported. It is well-known that the warming at the end of the last glaciation was punctuated by shifts to glacial climate, of which the 50-year-long Younger Dryas event is the most well-known. The extreme rapidity of climate change indicated by the GISP2 data is remarkable because it suggests that events in the last glaciation may have been a response to a sudden trigger in the North Atlantic climate system.

Sulfate and Nitrate Concentrations from a South Greenland Ice Core ONE OF THE MAJOR PROBLEMS ASSOCIATED with determining the effects of fossil fuel burning and acid deposition through time has [...]