Chemical compositions of past soluble aerosols reconstructed from Greenland and Antarctic ice cores

• Main Author: 大藪, 幾美
• Other Authors: Greve, Ralf, 渡辺, 力, 飯塚, 芳徳, 鈴木, 啓助
• Format: Other/Unknown Material
• Language: English
• Published: Hokkaido University
• Subjects: 468; Antarctic; Dome Fuji; Greenland; Antarc*; Antarctica; ice core
• Online Access: http://hdl.handle.net/2115/60906; https://doi.org/10.14943/doctoral.k11789

Aerosols play an important role in the global climate balance, and therefore they could be important in climate change. Chemical compositions of aerosols are one of the important information for understanding the role of aerosols. Therefore, it is required to clear spatial and temporal distributions of chemical compositions of aerosols. Polar ice cores preserve past atmospheric aerosols, which is a useful proxy for understanding the interaction between climate changes and atmospheric aerosols. One useful technique for reconstructing past soluble aerosols from ice cores is the determination of dissolved ion species. For instance, Na+ and Ca2+ are the major cations of both Greenland and Antarctic ice cores. The Na+ originates from sea-salt (NaCl), and the Ca2+ originates from terrestrial materials (CaCO3 and CaSO4). The NaCl and CaCO3 react with sulfuric acid (H2SO4), and change to Na2SO4 and CaSO4. It has been clearly known that the contribution of terrestrial aerosols is higher in the glacial period, whereas that of sea-salt aerosols is higher in the interglacial period. However, since salts and acids melt into ions, chemical compositions of soluble aerosols in the ice cores have not been cleared. To clarify the temporal variations in the chemical compositions of past soluble aerosols, and the interaction between past soluble aerosols (sulfate-salt aerosols) and temperature changes, this study investigated chemical compositions of soluble particles preserved in the Greenland and Antarctic ice cores by focusing on the last termination, the most recent climate transition. The ice core samples are selected from the sections from the last termination (the Last Glacial Maximum (LGM) to Holocene) of the Dome Fuji and Dome C (inland Antarctica) ice cores, and the sections of the last interglacial period to Holocene of the Greenland NEEM ice core. Using the ice-sublimation method, soluble salt particles were extracted without melting. Chemical components of extracted particles were analysed by scanning electron ...