Hydrophobic properties of laser induced periodic surface structures for ice coring drill

第6回極域科学シンポジウム[OM] 極域気水圏11月16日（月）　国立極地研究所１階交流アトリウ

Macroscopically uniform and flat lithium thin film formed by electrodeposition using multicomponent additives

It is well-known that the electrodeposition of lithium usually results in the formation of dendrites on the electrode surface. This limits the utilization of metallic lithium as a material for, for example, the negative electrodes of rechargeable batteries. In aqueous solutions, similar dendritic growth of metals is often observed during electrodeposition; however, utilization of multicomponent additives has overcome this shortcoming. Here, we report that the simultaneous utilization of four different additives greatly suppresses the formation of lithium dendrites during electrodeposition in a tetraglyme-based solution. The roles of the additives are discussed, based on the results of electrochemical quartz crystal microbalance measurements and X-ray photoelectron spectroscopy

Reduced marine biogenic sulphate flux in East Antarctica during glacial periods - Based on ion chemistry records from Dome Fuji ice core -

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / 2F Auditorium, National Institute of Polar Researc

Chemical compositions of sulfate particles during the Termination I in the Dome Fuji ice core

第2回極域科学シンポジウム　氷床コアセッション 11月16日（水） 国立極地研究所 2階大会議

Chemical Compounds of Water-Soluble Impurities in Dome Fuji Ice Core

The amounts of water-soluble impurities in ice cores have been widely discussed in past research on prehistoric climates; in those studies, the analysis of the soluble-aerosol signals of several ion concentrations took place after the ice cores were melted. However, the chemical compounds of the impurities being studied were unclear, due to the ionization of the impurities being caused by the melting of the ice cores. In this paper, the chemical compounds of water-soluble impurities in Dome Fuji ice core are discussed and analyzed using micro-Raman spectroscopy and ion chromatography. Raman spectroscopy helped identify micro-inclusions within ice grains as water-soluble impurities made up primarily of sodium sulfate formed in warm periods and calcium sulfate in cold periods. The major chemical compounds of the water-soluble impurities (sodium sulfate and calcium sulfate) were deduced by examining ion concentrations and the stability of chemical compounds. The amounts of impurities reflect the differences in climatic time periods, as the environment was acidic during warm times and reductive during cold.IV. Chemical properties and isotope

The chemical forms of water-soluble microparticles preserved in the Antarctic ice sheet during Termination I

This study clarifies changes in the chemical forms of microparticles during Termination I, the period of drastic climate change between the Last Glacial Maximum (LGM) and the Holocene. We determine the chemical forms of individual water-soluble microparticles through micro-Raman spectroscopy and compare the relative frequencies of different types with the ion concentrations in melted ice. Micro-Raman spectroscopy shows that Na2SO4・10H2O and MgSO4・11H2O are abundant in Holocene ice, while CaSO4・2H2O and other salts are abundant in LGM ice. Further, the number of CaSO4・2H2O particles is strongly correlated with the concentration of Ca2+ during Termination I. Taken together, the evidence strongly suggests that most of the Ca2+ exists as CaSO4・2H2O. The different compositions of microparticles from the Holocene and LGM can be explained by ion balance arguments

Magnesium methanesulfonate salt found in the Dome Fuji (Antarctica) ice core

Using micro-Raman spectroscopy, we identified the chemical forms of methanesulfonate salt particles in reference samples of the Dome Fuji (Antarctica) ice core. We found only (CH3SO3)2Mg・nH2O among methanesulfonate salts, and this salt particle is most prevalent in the Last Glacial Maximum (LGM) ice. We suggest that during the LGM, (CH3SO3)2Mg・nH2O may have formed in the atmosphere through the chemical reaction of CH3SO3H with sea salts, but probably not in the firn and ice due to the neutralization of acid in LGM ice of inland Antarctica

Chemical compositions of sulfate and chloride salts over the last termination reconstructed from the Dome Fuji ice core, inland Antarctica

The flux and chemical composition of aerosols impact the climate. Antarctic ice cores preserve the record of past atmospheric aerosols, providing useful information about past atmospheric environments. However, few studies have directly measured the chemical composition of aerosol particles preserved in ice cores. Here we present the chemical compositions of sulfate and chloride salts from aerosol particles in the Dome Fuji ice core. The analysis method involves ice sublimation, and the period covers the last termination, 25.0-11.0 thousand years before present (kyr B.P.), with a 350 year resolution. The major components of the soluble particles are CaSO4, Na2SO4, and NaCl. The dominant sulfate salt changes at 16.8 kyr B.P. from CaSO4, a glacial type, to Na2SO4, an interglacial type. The sulfate salt flux (CaSO4 plus Na2SO4) inversely correlates with delta O-18 in Dome Fuji over millennial timescales. This correlation is consistent with the idea that sulfate salt aerosols contributed to the last deglacial warming of inland Antarctica by reducing the aerosol indirect effect. Between 16.3 and 11.0 kyr B.P., the presence of NaCl suggests that winter atmospheric aerosols are preserved. A high NaCl/Na2SO4 fraction between 12.3 and 11.0 kyr B.P. indicates that the contribution from the transport of winter atmospheric aerosols increased during this period