FORA-WNP30

Four-dimensional Variational Ocean ReAnalysis for the Western North Pacific (FORA-WNP30) is the first-ever dataset covering the western North Pacific over the last three decades (1982-2014) at eddy-resolving resolution. This is the cooperative work of Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and Meteorological Research Institude, Japan Meteorological Agency (JMA/MRI) using the Earth Simulator. FORA-WNP30 was produced by using MRI Multivariate Ocean Variational Estimation system, version of 4-dimensional variational method (MOVE-4DVAR; Usui et al. 2015), the data assimilation system developed by the JMA/MRI. MOVE-4DVAR uses MRI.COM-WNP (Tsujino et al. 2006), eddy-resolving ocean model for Western North Pacific developed by JMA/MRI, as the forward model of ocean and sea ice. The settings of the assimilation system are as follows: - Ocean and sea ice model * Domain: 117°E-160°W, 15°N-65°N * Horizontal resolution: 1/10° (1/6° east of 160°E) longitude × 1/10° (1/6° north of 50°N) latitude * Number of vertical levels: 54 levels (0-6300m) - Assimilation method * Ocean: 4-dimensional variational method * Sea ice: objective analysis by minimum variance estimation and nudging * Assimilation cycle: 3 cycles in a month (day 1 to 10, 11 to 20, 21 to the end of month in each month), sea ice is nudeged to the daily analysis. - Assimilated observation * In situ temperature and salinity profiles from WOD2013 and GTSPP (0-1500m) * Gridded SST made by merging satellite and in situ observations (MGDSST; Kurihara et al., 2006 [in Japanese]) * SLA by satellites (TOPEX/Poseidon, Jason-1/2, ERS-1/2, Envisat, GFO, Cryosat) * SSM/I sea ice concentration data - Atmospheric forcing * daily-mean of JRA-55 (Kobayashi et al., 2015) - Analysis period * Jan. 1, 1982 to Dec. 31, 2014