Global cooling in intermediate glacial climate with northern ice sheets preconditions climatic instability with bipolar seesaw.

). The method is demonstrated for the Holocene and last glacial maximum regions of the Dome Fuji and GRIP ice cores. The dominant compounds depend only on the ion balance and the sequence of chemical reactions. In priority order, the principle salts are calcium sulfate, other sulfates, nitrate, chloride, and carbonate. The chemical abundances deduced by this method agree well with the results of Raman spectroscopy on individual salt inclusions. The abundances in the ice cores are shown to reflect differences in climatic periods (the acidic environment of the Holocene versus the reductive environment of the last glacial maximum) and regional conditions (the marine environment of Antarctica versus the continental environment of Greenland).

ABSTRACT. This study clarifies changes in the chemical forms of microparticles during

Movers and shakers: Vibrational states of CH4 molecules encaged in three clathrate hydrate structures are studied (see picture). Guest methane distribution in the structure‐H 512 and 435663 host cavities is revealed for the first time. Raman profiles of the CH4 vibration are dependent not only on types of water cages, but also on clathrate structures (guest compositions), suggesting distinctive differences in molecular interactions between the three hydrate systems.