High resolution reconstruction of hydrological cycle in the East Asia during the last deglaciation using terrestrial biomarkers

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16340158
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: HOKKAIDO UNIVERSITY
• Principal Investigator: YAMAMOTO Masanobu Hokkaido Univ., Faculty of Environmental Earth Science, Asso.Prof., 大学院地球環境科学研究院, 助教授 (60332475)
• Co-Investigator(Kenkyū-buntansha): IRINO Tomohisa Hokkaido Univ., Faculty of Environmental Earth Science, Inst., 大学院地球環境科学研究院, 助手 (70332476) ; TADA Ryuji Tokyo Univ., Grad. School of Science, Prof., 大学院理学系研究科, 教授 (30143366) ; IKEHARA Minoru Kochi Univ., Center for Advanced Marine Core Research, Asso.Prof., 海洋コア総合研究センター, 助教授 (90335919) ; OBA Tadamichi Hokkaido Univ., Emeritus Prof., 名誉教授 (60013588)
• Project Period (FY): 2004 – 2006
• Keywords: Paleoceanography / Paleo-c1imate / East Asia / precipitation / ENSO / Asian monsoon / marine core / biomarker

Research Abstract

This study aims at examining the role of El Nino-Southern Oscillation in last deglacial warming and hydrological changes by reconstructing the latitudinal gradient of precipitation along the East Asian margin during the last deglaciation. For this purpose, we analyzed terrestrial biomarkers in marine cores from five different locations from the tropical to subarctic regions.
Variations in lignin, terrestrial biomarkers and pollen compositions and biomarker-specific deuterium/hydrogen ratio indicated a dry climate in the regions north of 30 degrees north and an increase of precipitation at the site of 8 degrees north during the last deglaciation. This enhanced latitudinal gradient of precipitation was presumably caused by the combination of El Nino-like atmospheric pattern in the North Pacific and the intensified tropical convection.
Other findings are as follows. The winter Aleutian Low was intensified during the last two deglaciations. Winter monsoon was stronger during the last deglaciation. The Holocene 1500-year oscillation was found in the sea surface temperature record from the Japan margin.

Research Products

• [Journal Article] Monsoon related changes in sea surface productivity and water column denitrification in the Eastern Arabian Sea during the last glacial cycle. (2007)
  • Author(s): Banakar, V.K., Oba, T., Chodankar, A.R., Kuramoto, T., Yamamoto, M., Minagawa, M.
  • Journal Title: Marine Geology 238 Pages: 115-117
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] The California Current System during the last 136,000 years : Response of the North Pacific High to precessional forcing. (2007)
  • Author(s): Yamamoto, M., Yamamuro, M., Tanaka, Y.
  • Journal Title: Quaternary Science Reviews 26 Pages: 405-414
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] GHO2航海で採取された十勝沖表層堆積物中の花粉・胞子群. (2007)
  • Author(s): 五十嵐八枝子, 山本正伸, 野田篤
  • Journal Title: 地質調査総合センター速報 (印刷中)
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 十勝冲海底コア・GHO2-1030の花粉群による北海道東部地域21,000年間の古植生復元 (2007)
  • Author(s): 五十嵐八枝子, 山本正伸, 池原研
  • Journal Title: 地質調査総合センター速報 (印刷中)
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Monsoon related changes in sea surface productivity and water column denitrification in the Eastern Arabian Sea during the last glacial cycle. (2007)
  • Author(s): Banakar, V.K., Oba, T., Chodankar, A.R., Kuramoto, T., Yamamoto, M., Minagawa, M.
  • Journal Title: Marine Geology 238, 115-117 doi:10,1016/j.margeo.2006.10.039
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Long term Aleutian Low dynamics and obliquity-controlled oceanic primary production in the mid-latitude western North Pacific (Core MD01-2421) during the last 145,000 years. (2006)
  • Author(s): Ueshima, T., Yamamoto, M., Irino, T., Oba, T., Minagawa, M., Narita, H., Murayama, M.
  • Journal Title: Global and Planetary Change 53 Pages: 21-28
  • Description: 「研究成果報告書概要(和文)」より