Okitsugu Watanabe

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The Milankovitch theory of climate change proposes that glacial-interglacial cycles are driven by changes in summer insolation at high northern latitudes. The timing of climate change in the Southern Hemisphere at glacial-interglacial transitions (which are known as terminations) relative to variations in summer insolation in the Northern Hemisphere is an(More)
A method for measuring the concentration of methyl chloride (CH3Cl) in air trapped in an ice core was developed. The method combines the air extraction by milling the ice core samples under vacuum and the analysis of the extracted air with a cryogenic preconcentration/gas chromatograph/mass spectrometry system. The method was applied to air from Antarctic(More)
Sophisticated nozzle and spray-drier were newly developed. The nozzle type was that of four-phase spraying, where two liquid streams and two air streams were blown off. The spray pattern from the nozzle was of a hollow-cone type. Mean diameter of droplets in the mist was 13.2 microm in weight average in the condition of blowing at 776 g/min in air flow and(More)
Climatic variabilities on millennial and longer time scales with a bipolar seesaw pattern have been documented in paleoclimatic records, but their frequencies, relationships with mean climatic state, and mechanisms remain unclear. Understanding the processes and sensitivities that underlie these changes will underpin better understanding of the climate(More)
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