How do pCO2 and nutrient observations capture the interannual surface variability in the tropical Pacific?

Sayaka Yasunaka, JAMSTEC, Kanagawa, Japan, Shinya Kouketsu, JAMSTEC, Yokosuka, Japan, Akihiko Murata, Japan Agency for Marine-Earth Science and Technology, Research & Development Center for Global Change, Yokosuka, Japan, Peter G Strutton, University of Tasmania, Institute for Marine and Antarctic Studies (IMAS), ARC Centre of Excellence for Climate System Science, Hobart, TAS, Australia, Adrienne J Sutton, NOAA Pacific Marine Environmental Laboratory, Seattle, WA, United States, Shin-ichiro Nakaoka, CGER/NIES, Tsukuba, Japan and Yukihiro Nojiri, Hirosaki University, Hirosaki, Japan