[A-OS19] Marine ecosystems and biogeochemical cycles: theory, observation and modeling

[AOS19-06] Basin-scale Relations between Marine Ecosystem Indices and Physical Environment in North Pacific

*Emi Yati^1,6, Shoshiro Minobe^1,2, Nathan Mantua³, Shin-ichi Ito⁴, Emanuele Di Lorenzo⁵ (1.Department of Natural History Sciences, Graduate School of Science, Hokkaido University., 2.Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University. E-mail: [e-mail], 3.Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, California 95060, USA., 4.Atmosphere and Ocean Research Institute, University of Tokyo., 5.School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA., 6.Remote Sensing Application Center, Indonesian National Institute of Aeronautics and Space.)

Keywords:Marine ecosystem indices, Decadal variability, Physical environment , Climate changes, Basin-scale fisheries, North Pacific

To understand how marine ecosystem varies and how that variability is related to physical climate conditions, it is useful to conduct a multivariate analysis using large number (several tens) of marine ecosystem indices (e.g., Hare and Mantua 2000) and this type of analysis is referred to as large multivariate analysis (LMA). In this study we conduct an LMA for the marine ecosystem for whole North Pacific, for the first time to the author's knowledge, using the marine ecosystem indicators both in the eastern and western side of the basin. The main analysis method is Empirical Orthogonal Function (EOF) of marine ecosystem indicators and the relation of the marine ecosystem EOFs and physical climate condition is examined. The EOFs are calculated for marine ecosystem indicators in the western and eastern basin separatory or combined. The results indicate that the first EOF mode is characterized by a long-term trend, irrespective of the EOF domain. The second mode varies on multi-decadal timescale in the eastern North Pacific, and on somewhat shorter timescale in the western North Pacific. It appears that the first mode is related to the overall warming over the North Pacific, but the second modes are closely related to decadal climate modes, i.e., the Pacific (inter-)Decadal Oscillation and North Pacific Gyre Circulation modes. The implications of the present results for marine ecosystem predictability will be discussed.